diff options
author | Jens Axboe <axboe@kernel.dk> | 2013-12-31 11:51:02 -0500 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2013-12-31 11:51:02 -0500 |
commit | b28bc9b38c52f63f43e3fd875af982f2240a2859 (patch) | |
tree | 76cdb7b52b58f5685993cc15ed81d1c903023358 /Documentation | |
parent | 8d30726912cb39c3a3ebde06214d54861f8fdde2 (diff) | |
parent | 802eee95bde72fd0cd0f3a5b2098375a487d1eda (diff) |
Merge tag 'v3.13-rc6' into for-3.14/core
Needed to bring blk-mq uptodate, since changes have been going in
since for-3.14/core was established.
Fixup merge issues related to the immutable biovec changes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Conflicts:
block/blk-flush.c
fs/btrfs/check-integrity.c
fs/btrfs/extent_io.c
fs/btrfs/scrub.c
fs/logfs/dev_bdev.c
Diffstat (limited to 'Documentation')
34 files changed, 1168 insertions, 68 deletions
diff --git a/Documentation/Changes b/Documentation/Changes index b17580885273..07c75d18154e 100644 --- a/Documentation/Changes +++ b/Documentation/Changes | |||
@@ -196,13 +196,6 @@ chmod 0644 /dev/cpu/microcode | |||
196 | as root before you can use this. You'll probably also want to | 196 | as root before you can use this. You'll probably also want to |
197 | get the user-space microcode_ctl utility to use with this. | 197 | get the user-space microcode_ctl utility to use with this. |
198 | 198 | ||
199 | Powertweak | ||
200 | ---------- | ||
201 | |||
202 | If you are running v0.1.17 or earlier, you should upgrade to | ||
203 | version v0.99.0 or higher. Running old versions may cause problems | ||
204 | with programs using shared memory. | ||
205 | |||
206 | udev | 199 | udev |
207 | ---- | 200 | ---- |
208 | udev is a userspace application for populating /dev dynamically with | 201 | udev is a userspace application for populating /dev dynamically with |
@@ -366,10 +359,6 @@ Intel P6 microcode | |||
366 | ------------------ | 359 | ------------------ |
367 | o <http://www.urbanmyth.org/microcode/> | 360 | o <http://www.urbanmyth.org/microcode/> |
368 | 361 | ||
369 | Powertweak | ||
370 | ---------- | ||
371 | o <http://powertweak.sourceforge.net/> | ||
372 | |||
373 | udev | 362 | udev |
374 | ---- | 363 | ---- |
375 | o <http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev.html> | 364 | o <http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev.html> |
diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl index 6c9d9d37c83a..f5170082bdb3 100644 --- a/Documentation/DocBook/device-drivers.tmpl +++ b/Documentation/DocBook/device-drivers.tmpl | |||
@@ -58,7 +58,7 @@ | |||
58 | </sect1> | 58 | </sect1> |
59 | <sect1><title>Wait queues and Wake events</title> | 59 | <sect1><title>Wait queues and Wake events</title> |
60 | !Iinclude/linux/wait.h | 60 | !Iinclude/linux/wait.h |
61 | !Ekernel/wait.c | 61 | !Ekernel/sched/wait.c |
62 | </sect1> | 62 | </sect1> |
63 | <sect1><title>High-resolution timers</title> | 63 | <sect1><title>High-resolution timers</title> |
64 | !Iinclude/linux/ktime.h | 64 | !Iinclude/linux/ktime.h |
diff --git a/Documentation/DocBook/media/v4l/vidioc-expbuf.xml b/Documentation/DocBook/media/v4l/vidioc-expbuf.xml index e287c8fc803b..4165e7bfa4ff 100644 --- a/Documentation/DocBook/media/v4l/vidioc-expbuf.xml +++ b/Documentation/DocBook/media/v4l/vidioc-expbuf.xml | |||
@@ -73,7 +73,8 @@ range from zero to the maximal number of valid planes for the currently active | |||
73 | format. For the single-planar API, applications must set <structfield> plane | 73 | format. For the single-planar API, applications must set <structfield> plane |
74 | </structfield> to zero. Additional flags may be posted in the <structfield> | 74 | </structfield> to zero. Additional flags may be posted in the <structfield> |
75 | flags </structfield> field. Refer to a manual for open() for details. | 75 | flags </structfield> field. Refer to a manual for open() for details. |
76 | Currently only O_CLOEXEC is supported. All other fields must be set to zero. | 76 | Currently only O_CLOEXEC, O_RDONLY, O_WRONLY, and O_RDWR are supported. All |
77 | other fields must be set to zero. | ||
77 | In the case of multi-planar API, every plane is exported separately using | 78 | In the case of multi-planar API, every plane is exported separately using |
78 | multiple <constant> VIDIOC_EXPBUF </constant> calls. </para> | 79 | multiple <constant> VIDIOC_EXPBUF </constant> calls. </para> |
79 | 80 | ||
@@ -170,8 +171,9 @@ multi-planar API. Otherwise this value must be set to zero. </entry> | |||
170 | <entry>__u32</entry> | 171 | <entry>__u32</entry> |
171 | <entry><structfield>flags</structfield></entry> | 172 | <entry><structfield>flags</structfield></entry> |
172 | <entry>Flags for the newly created file, currently only <constant> | 173 | <entry>Flags for the newly created file, currently only <constant> |
173 | O_CLOEXEC </constant> is supported, refer to the manual of open() for more | 174 | O_CLOEXEC </constant>, <constant>O_RDONLY</constant>, <constant>O_WRONLY |
174 | details.</entry> | 175 | </constant>, and <constant>O_RDWR</constant> are supported, refer to the manual |
176 | of open() for more details.</entry> | ||
175 | </row> | 177 | </row> |
176 | <row> | 178 | <row> |
177 | <entry>__s32</entry> | 179 | <entry>__s32</entry> |
diff --git a/Documentation/assoc_array.txt b/Documentation/assoc_array.txt index f4faec0f66e4..2f2c6cdd73c0 100644 --- a/Documentation/assoc_array.txt +++ b/Documentation/assoc_array.txt | |||
@@ -164,10 +164,10 @@ This points to a number of methods, all of which need to be provided: | |||
164 | 164 | ||
165 | (4) Diff the index keys of two objects. | 165 | (4) Diff the index keys of two objects. |
166 | 166 | ||
167 | int (*diff_objects)(const void *a, const void *b); | 167 | int (*diff_objects)(const void *object, const void *index_key); |
168 | 168 | ||
169 | Return the bit position at which the index keys of two objects differ or | 169 | Return the bit position at which the index key of the specified object |
170 | -1 if they are the same. | 170 | differs from the given index key or -1 if they are the same. |
171 | 171 | ||
172 | 172 | ||
173 | (5) Free an object. | 173 | (5) Free an object. |
diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt new file mode 100644 index 000000000000..b2830b435895 --- /dev/null +++ b/Documentation/block/null_blk.txt | |||
@@ -0,0 +1,72 @@ | |||
1 | Null block device driver | ||
2 | ================================================================================ | ||
3 | |||
4 | I. Overview | ||
5 | |||
6 | The null block device (/dev/nullb*) is used for benchmarking the various | ||
7 | block-layer implementations. It emulates a block device of X gigabytes in size. | ||
8 | The following instances are possible: | ||
9 | |||
10 | Single-queue block-layer | ||
11 | - Request-based. | ||
12 | - Single submission queue per device. | ||
13 | - Implements IO scheduling algorithms (CFQ, Deadline, noop). | ||
14 | Multi-queue block-layer | ||
15 | - Request-based. | ||
16 | - Configurable submission queues per device. | ||
17 | No block-layer (Known as bio-based) | ||
18 | - Bio-based. IO requests are submitted directly to the device driver. | ||
19 | - Directly accepts bio data structure and returns them. | ||
20 | |||
21 | All of them have a completion queue for each core in the system. | ||
22 | |||
23 | II. Module parameters applicable for all instances: | ||
24 | |||
25 | queue_mode=[0-2]: Default: 2-Multi-queue | ||
26 | Selects which block-layer the module should instantiate with. | ||
27 | |||
28 | 0: Bio-based. | ||
29 | 1: Single-queue. | ||
30 | 2: Multi-queue. | ||
31 | |||
32 | home_node=[0--nr_nodes]: Default: NUMA_NO_NODE | ||
33 | Selects what CPU node the data structures are allocated from. | ||
34 | |||
35 | gb=[Size in GB]: Default: 250GB | ||
36 | The size of the device reported to the system. | ||
37 | |||
38 | bs=[Block size (in bytes)]: Default: 512 bytes | ||
39 | The block size reported to the system. | ||
40 | |||
41 | nr_devices=[Number of devices]: Default: 2 | ||
42 | Number of block devices instantiated. They are instantiated as /dev/nullb0, | ||
43 | etc. | ||
44 | |||
45 | irq_mode=[0-2]: Default: 1-Soft-irq | ||
46 | The completion mode used for completing IOs to the block-layer. | ||
47 | |||
48 | 0: None. | ||
49 | 1: Soft-irq. Uses IPI to complete IOs across CPU nodes. Simulates the overhead | ||
50 | when IOs are issued from another CPU node than the home the device is | ||
51 | connected to. | ||
52 | 2: Timer: Waits a specific period (completion_nsec) for each IO before | ||
53 | completion. | ||
54 | |||
55 | completion_nsec=[ns]: Default: 10.000ns | ||
56 | Combined with irq_mode=2 (timer). The time each completion event must wait. | ||
57 | |||
58 | submit_queues=[0..nr_cpus]: | ||
59 | The number of submission queues attached to the device driver. If unset, it | ||
60 | defaults to 1 on single-queue and bio-based instances. For multi-queue, | ||
61 | it is ignored when use_per_node_hctx module parameter is 1. | ||
62 | |||
63 | hw_queue_depth=[0..qdepth]: Default: 64 | ||
64 | The hardware queue depth of the device. | ||
65 | |||
66 | III: Multi-queue specific parameters | ||
67 | |||
68 | use_per_node_hctx=[0/1]: Default: 0 | ||
69 | 0: The number of submit queues are set to the value of the submit_queues | ||
70 | parameter. | ||
71 | 1: The multi-queue block layer is instantiated with a hardware dispatch | ||
72 | queue for each CPU node in the system. | ||
diff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt index 274752f8bdf9..719320b5ed3f 100644 --- a/Documentation/device-mapper/cache.txt +++ b/Documentation/device-mapper/cache.txt | |||
@@ -266,10 +266,12 @@ E.g. | |||
266 | Invalidation is removing an entry from the cache without writing it | 266 | Invalidation is removing an entry from the cache without writing it |
267 | back. Cache blocks can be invalidated via the invalidate_cblocks | 267 | back. Cache blocks can be invalidated via the invalidate_cblocks |
268 | message, which takes an arbitrary number of cblock ranges. Each cblock | 268 | message, which takes an arbitrary number of cblock ranges. Each cblock |
269 | must be expressed as a decimal value, in the future a variant message | 269 | range's end value is "one past the end", meaning 5-10 expresses a range |
270 | that takes cblock ranges expressed in hexidecimal may be needed to | 270 | of values from 5 to 9. Each cblock must be expressed as a decimal |
271 | better support efficient invalidation of larger caches. The cache must | 271 | value, in the future a variant message that takes cblock ranges |
272 | be in passthrough mode when invalidate_cblocks is used. | 272 | expressed in hexidecimal may be needed to better support efficient |
273 | invalidation of larger caches. The cache must be in passthrough mode | ||
274 | when invalidate_cblocks is used. | ||
273 | 275 | ||
274 | invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]* | 276 | invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]* |
275 | 277 | ||
diff --git a/Documentation/devicetree/bindings/arm/omap/mpu.txt b/Documentation/devicetree/bindings/arm/omap/mpu.txt index 1a5a42ce21bb..83f405bde138 100644 --- a/Documentation/devicetree/bindings/arm/omap/mpu.txt +++ b/Documentation/devicetree/bindings/arm/omap/mpu.txt | |||
@@ -7,10 +7,18 @@ The MPU contain CPUs, GIC, L2 cache and a local PRCM. | |||
7 | Required properties: | 7 | Required properties: |
8 | - compatible : Should be "ti,omap3-mpu" for OMAP3 | 8 | - compatible : Should be "ti,omap3-mpu" for OMAP3 |
9 | Should be "ti,omap4-mpu" for OMAP4 | 9 | Should be "ti,omap4-mpu" for OMAP4 |
10 | Should be "ti,omap5-mpu" for OMAP5 | ||
10 | - ti,hwmods: "mpu" | 11 | - ti,hwmods: "mpu" |
11 | 12 | ||
12 | Examples: | 13 | Examples: |
13 | 14 | ||
15 | - For an OMAP5 SMP system: | ||
16 | |||
17 | mpu { | ||
18 | compatible = "ti,omap5-mpu"; | ||
19 | ti,hwmods = "mpu" | ||
20 | }; | ||
21 | |||
14 | - For an OMAP4 SMP system: | 22 | - For an OMAP4 SMP system: |
15 | 23 | ||
16 | mpu { | 24 | mpu { |
diff --git a/Documentation/devicetree/bindings/arm/pmu.txt b/Documentation/devicetree/bindings/arm/pmu.txt index 343781b9f246..3e1e498fea96 100644 --- a/Documentation/devicetree/bindings/arm/pmu.txt +++ b/Documentation/devicetree/bindings/arm/pmu.txt | |||
@@ -7,6 +7,7 @@ representation in the device tree should be done as under:- | |||
7 | Required properties: | 7 | Required properties: |
8 | 8 | ||
9 | - compatible : should be one of | 9 | - compatible : should be one of |
10 | "arm,armv8-pmuv3" | ||
10 | "arm,cortex-a15-pmu" | 11 | "arm,cortex-a15-pmu" |
11 | "arm,cortex-a9-pmu" | 12 | "arm,cortex-a9-pmu" |
12 | "arm,cortex-a8-pmu" | 13 | "arm,cortex-a8-pmu" |
diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt index 47ada1dff216..5d49f2b37f68 100644 --- a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt +++ b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt | |||
@@ -49,7 +49,7 @@ adc@12D10000 { | |||
49 | /* NTC thermistor is a hwmon device */ | 49 | /* NTC thermistor is a hwmon device */ |
50 | ncp15wb473@0 { | 50 | ncp15wb473@0 { |
51 | compatible = "ntc,ncp15wb473"; | 51 | compatible = "ntc,ncp15wb473"; |
52 | pullup-uV = <1800000>; | 52 | pullup-uv = <1800000>; |
53 | pullup-ohm = <47000>; | 53 | pullup-ohm = <47000>; |
54 | pulldown-ohm = <0>; | 54 | pulldown-ohm = <0>; |
55 | io-channels = <&adc 4>; | 55 | io-channels = <&adc 4>; |
diff --git a/Documentation/devicetree/bindings/clock/exynos4-clock.txt b/Documentation/devicetree/bindings/clock/exynos4-clock.txt index c6bf8a6c8f52..a2ac2d9ac71a 100644 --- a/Documentation/devicetree/bindings/clock/exynos4-clock.txt +++ b/Documentation/devicetree/bindings/clock/exynos4-clock.txt | |||
@@ -6,7 +6,7 @@ SoC's in the Exynos4 family. | |||
6 | 6 | ||
7 | Required Properties: | 7 | Required Properties: |
8 | 8 | ||
9 | - comptible: should be one of the following. | 9 | - compatible: should be one of the following. |
10 | - "samsung,exynos4210-clock" - controller compatible with Exynos4210 SoC. | 10 | - "samsung,exynos4210-clock" - controller compatible with Exynos4210 SoC. |
11 | - "samsung,exynos4412-clock" - controller compatible with Exynos4412 SoC. | 11 | - "samsung,exynos4412-clock" - controller compatible with Exynos4412 SoC. |
12 | 12 | ||
diff --git a/Documentation/devicetree/bindings/clock/exynos5250-clock.txt b/Documentation/devicetree/bindings/clock/exynos5250-clock.txt index 24765c146e31..46f5c791ea0d 100644 --- a/Documentation/devicetree/bindings/clock/exynos5250-clock.txt +++ b/Documentation/devicetree/bindings/clock/exynos5250-clock.txt | |||
@@ -5,7 +5,7 @@ controllers within the Exynos5250 SoC. | |||
5 | 5 | ||
6 | Required Properties: | 6 | Required Properties: |
7 | 7 | ||
8 | - comptible: should be one of the following. | 8 | - compatible: should be one of the following. |
9 | - "samsung,exynos5250-clock" - controller compatible with Exynos5250 SoC. | 9 | - "samsung,exynos5250-clock" - controller compatible with Exynos5250 SoC. |
10 | 10 | ||
11 | - reg: physical base address of the controller and length of memory mapped | 11 | - reg: physical base address of the controller and length of memory mapped |
diff --git a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt index 32aa34ecad36..458f34789e5d 100644 --- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt +++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt | |||
@@ -5,7 +5,7 @@ controllers within the Exynos5420 SoC. | |||
5 | 5 | ||
6 | Required Properties: | 6 | Required Properties: |
7 | 7 | ||
8 | - comptible: should be one of the following. | 8 | - compatible: should be one of the following. |
9 | - "samsung,exynos5420-clock" - controller compatible with Exynos5420 SoC. | 9 | - "samsung,exynos5420-clock" - controller compatible with Exynos5420 SoC. |
10 | 10 | ||
11 | - reg: physical base address of the controller and length of memory mapped | 11 | - reg: physical base address of the controller and length of memory mapped |
diff --git a/Documentation/devicetree/bindings/clock/exynos5440-clock.txt b/Documentation/devicetree/bindings/clock/exynos5440-clock.txt index 4499e9966bc9..9955dc9c7d96 100644 --- a/Documentation/devicetree/bindings/clock/exynos5440-clock.txt +++ b/Documentation/devicetree/bindings/clock/exynos5440-clock.txt | |||
@@ -5,7 +5,7 @@ controllers within the Exynos5440 SoC. | |||
5 | 5 | ||
6 | Required Properties: | 6 | Required Properties: |
7 | 7 | ||
8 | - comptible: should be "samsung,exynos5440-clock". | 8 | - compatible: should be "samsung,exynos5440-clock". |
9 | 9 | ||
10 | - reg: physical base address of the controller and length of memory mapped | 10 | - reg: physical base address of the controller and length of memory mapped |
11 | region. | 11 | region. |
diff --git a/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt b/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt index b0019eb5330e..798cfc9d3839 100644 --- a/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt +++ b/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt | |||
@@ -5,16 +5,42 @@ This is for the non-QE/CPM/GUTs GPIO controllers as found on | |||
5 | 5 | ||
6 | Every GPIO controller node must have #gpio-cells property defined, | 6 | Every GPIO controller node must have #gpio-cells property defined, |
7 | this information will be used to translate gpio-specifiers. | 7 | this information will be used to translate gpio-specifiers. |
8 | See bindings/gpio/gpio.txt for details of how to specify GPIO | ||
9 | information for devices. | ||
10 | |||
11 | The GPIO module usually is connected to the SoC's internal interrupt | ||
12 | controller, see bindings/interrupt-controller/interrupts.txt (the | ||
13 | interrupt client nodes section) for details how to specify this GPIO | ||
14 | module's interrupt. | ||
15 | |||
16 | The GPIO module may serve as another interrupt controller (cascaded to | ||
17 | the SoC's internal interrupt controller). See the interrupt controller | ||
18 | nodes section in bindings/interrupt-controller/interrupts.txt for | ||
19 | details. | ||
8 | 20 | ||
9 | Required properties: | 21 | Required properties: |
10 | - compatible : "fsl,<CHIP>-gpio" followed by "fsl,mpc8349-gpio" for | 22 | - compatible: "fsl,<chip>-gpio" followed by "fsl,mpc8349-gpio" |
11 | 83xx, "fsl,mpc8572-gpio" for 85xx and "fsl,mpc8610-gpio" for 86xx. | 23 | for 83xx, "fsl,mpc8572-gpio" for 85xx, or |
12 | - #gpio-cells : Should be two. The first cell is the pin number and the | 24 | "fsl,mpc8610-gpio" for 86xx. |
13 | second cell is used to specify optional parameters (currently unused). | 25 | - #gpio-cells: Should be two. The first cell is the pin number |
14 | - interrupts : Interrupt mapping for GPIO IRQ. | 26 | and the second cell is used to specify optional |
15 | - interrupt-parent : Phandle for the interrupt controller that | 27 | parameters (currently unused). |
16 | services interrupts for this device. | 28 | - interrupt-parent: Phandle for the interrupt controller that |
17 | - gpio-controller : Marks the port as GPIO controller. | 29 | services interrupts for this device. |
30 | - interrupts: Interrupt mapping for GPIO IRQ. | ||
31 | - gpio-controller: Marks the port as GPIO controller. | ||
32 | |||
33 | Optional properties: | ||
34 | - interrupt-controller: Empty boolean property which marks the GPIO | ||
35 | module as an IRQ controller. | ||
36 | - #interrupt-cells: Should be two. Defines the number of integer | ||
37 | cells required to specify an interrupt within | ||
38 | this interrupt controller. The first cell | ||
39 | defines the pin number, the second cell | ||
40 | defines additional flags (trigger type, | ||
41 | trigger polarity). Note that the available | ||
42 | set of trigger conditions supported by the | ||
43 | GPIO module depends on the actual SoC. | ||
18 | 44 | ||
19 | Example of gpio-controller nodes for a MPC8347 SoC: | 45 | Example of gpio-controller nodes for a MPC8347 SoC: |
20 | 46 | ||
@@ -22,39 +48,27 @@ Example of gpio-controller nodes for a MPC8347 SoC: | |||
22 | #gpio-cells = <2>; | 48 | #gpio-cells = <2>; |
23 | compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio"; | 49 | compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio"; |
24 | reg = <0xc00 0x100>; | 50 | reg = <0xc00 0x100>; |
25 | interrupts = <74 0x8>; | ||
26 | interrupt-parent = <&ipic>; | 51 | interrupt-parent = <&ipic>; |
52 | interrupts = <74 0x8>; | ||
27 | gpio-controller; | 53 | gpio-controller; |
54 | interrupt-controller; | ||
55 | #interrupt-cells = <2>; | ||
28 | }; | 56 | }; |
29 | 57 | ||
30 | gpio2: gpio-controller@d00 { | 58 | gpio2: gpio-controller@d00 { |
31 | #gpio-cells = <2>; | 59 | #gpio-cells = <2>; |
32 | compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio"; | 60 | compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio"; |
33 | reg = <0xd00 0x100>; | 61 | reg = <0xd00 0x100>; |
34 | interrupts = <75 0x8>; | ||
35 | interrupt-parent = <&ipic>; | 62 | interrupt-parent = <&ipic>; |
63 | interrupts = <75 0x8>; | ||
36 | gpio-controller; | 64 | gpio-controller; |
37 | }; | 65 | }; |
38 | 66 | ||
39 | See booting-without-of.txt for details of how to specify GPIO | 67 | Example of a peripheral using the GPIO module as an IRQ controller: |
40 | information for devices. | ||
41 | |||
42 | To use GPIO pins as interrupt sources for peripherals, specify the | ||
43 | GPIO controller as the interrupt parent and define GPIO number + | ||
44 | trigger mode using the interrupts property, which is defined like | ||
45 | this: | ||
46 | |||
47 | interrupts = <number trigger>, where: | ||
48 | - number: GPIO pin (0..31) | ||
49 | - trigger: trigger mode: | ||
50 | 2 = trigger on falling edge | ||
51 | 3 = trigger on both edges | ||
52 | |||
53 | Example of device using this is: | ||
54 | 68 | ||
55 | funkyfpga@0 { | 69 | funkyfpga@0 { |
56 | compatible = "funky-fpga"; | 70 | compatible = "funky-fpga"; |
57 | ... | 71 | ... |
58 | interrupts = <4 3>; | ||
59 | interrupt-parent = <&gpio1>; | 72 | interrupt-parent = <&gpio1>; |
73 | interrupts = <4 3>; | ||
60 | }; | 74 | }; |
diff --git a/Documentation/devicetree/bindings/i2c/i2c-omap.txt b/Documentation/devicetree/bindings/i2c/i2c-omap.txt index 56564aa4b444..7e49839d4124 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-omap.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-omap.txt | |||
@@ -1,7 +1,8 @@ | |||
1 | I2C for OMAP platforms | 1 | I2C for OMAP platforms |
2 | 2 | ||
3 | Required properties : | 3 | Required properties : |
4 | - compatible : Must be "ti,omap3-i2c" or "ti,omap4-i2c" | 4 | - compatible : Must be "ti,omap2420-i2c", "ti,omap2430-i2c", "ti,omap3-i2c" |
5 | or "ti,omap4-i2c" | ||
5 | - ti,hwmods : Must be "i2c<n>", n being the instance number (1-based) | 6 | - ti,hwmods : Must be "i2c<n>", n being the instance number (1-based) |
6 | - #address-cells = <1>; | 7 | - #address-cells = <1>; |
7 | - #size-cells = <0>; | 8 | - #size-cells = <0>; |
diff --git a/Documentation/devicetree/bindings/mmc/ti-omap.txt b/Documentation/devicetree/bindings/mmc/ti-omap.txt new file mode 100644 index 000000000000..8de579969763 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/ti-omap.txt | |||
@@ -0,0 +1,54 @@ | |||
1 | * TI MMC host controller for OMAP1 and 2420 | ||
2 | |||
3 | The MMC Host Controller on TI OMAP1 and 2420 family provides | ||
4 | an interface for MMC, SD, and SDIO types of memory cards. | ||
5 | |||
6 | This file documents differences between the core properties described | ||
7 | by mmc.txt and the properties used by the omap mmc driver. | ||
8 | |||
9 | Note that this driver will not work with omap2430 or later omaps, | ||
10 | please see the omap hsmmc driver for the current omaps. | ||
11 | |||
12 | Required properties: | ||
13 | - compatible: Must be "ti,omap2420-mmc", for OMAP2420 controllers | ||
14 | - ti,hwmods: For 2420, must be "msdi<n>", where n is controller | ||
15 | instance starting 1 | ||
16 | |||
17 | Examples: | ||
18 | |||
19 | msdi1: mmc@4809c000 { | ||
20 | compatible = "ti,omap2420-mmc"; | ||
21 | ti,hwmods = "msdi1"; | ||
22 | reg = <0x4809c000 0x80>; | ||
23 | interrupts = <83>; | ||
24 | dmas = <&sdma 61 &sdma 62>; | ||
25 | dma-names = "tx", "rx"; | ||
26 | }; | ||
27 | |||
28 | * TI MMC host controller for OMAP1 and 2420 | ||
29 | |||
30 | The MMC Host Controller on TI OMAP1 and 2420 family provides | ||
31 | an interface for MMC, SD, and SDIO types of memory cards. | ||
32 | |||
33 | This file documents differences between the core properties described | ||
34 | by mmc.txt and the properties used by the omap mmc driver. | ||
35 | |||
36 | Note that this driver will not work with omap2430 or later omaps, | ||
37 | please see the omap hsmmc driver for the current omaps. | ||
38 | |||
39 | Required properties: | ||
40 | - compatible: Must be "ti,omap2420-mmc", for OMAP2420 controllers | ||
41 | - ti,hwmods: For 2420, must be "msdi<n>", where n is controller | ||
42 | instance starting 1 | ||
43 | |||
44 | Examples: | ||
45 | |||
46 | msdi1: mmc@4809c000 { | ||
47 | compatible = "ti,omap2420-mmc"; | ||
48 | ti,hwmods = "msdi1"; | ||
49 | reg = <0x4809c000 0x80>; | ||
50 | interrupts = <83>; | ||
51 | dmas = <&sdma 61 &sdma 62>; | ||
52 | dma-names = "tx", "rx"; | ||
53 | }; | ||
54 | |||
diff --git a/Documentation/devicetree/bindings/net/davinci_emac.txt b/Documentation/devicetree/bindings/net/davinci_emac.txt index 48b259e29e87..bad381faf036 100644 --- a/Documentation/devicetree/bindings/net/davinci_emac.txt +++ b/Documentation/devicetree/bindings/net/davinci_emac.txt | |||
@@ -4,7 +4,7 @@ This file provides information, what the device node | |||
4 | for the davinci_emac interface contains. | 4 | for the davinci_emac interface contains. |
5 | 5 | ||
6 | Required properties: | 6 | Required properties: |
7 | - compatible: "ti,davinci-dm6467-emac"; | 7 | - compatible: "ti,davinci-dm6467-emac" or "ti,am3517-emac" |
8 | - reg: Offset and length of the register set for the device | 8 | - reg: Offset and length of the register set for the device |
9 | - ti,davinci-ctrl-reg-offset: offset to control register | 9 | - ti,davinci-ctrl-reg-offset: offset to control register |
10 | - ti,davinci-ctrl-mod-reg-offset: offset to control module register | 10 | - ti,davinci-ctrl-mod-reg-offset: offset to control module register |
diff --git a/Documentation/devicetree/bindings/net/fsl-fec.txt b/Documentation/devicetree/bindings/net/fsl-fec.txt index d53639221403..845ff848d895 100644 --- a/Documentation/devicetree/bindings/net/fsl-fec.txt +++ b/Documentation/devicetree/bindings/net/fsl-fec.txt | |||
@@ -15,6 +15,7 @@ Optional properties: | |||
15 | only if property "phy-reset-gpios" is available. Missing the property | 15 | only if property "phy-reset-gpios" is available. Missing the property |
16 | will have the duration be 1 millisecond. Numbers greater than 1000 are | 16 | will have the duration be 1 millisecond. Numbers greater than 1000 are |
17 | invalid and 1 millisecond will be used instead. | 17 | invalid and 1 millisecond will be used instead. |
18 | - phy-supply: regulator that powers the Ethernet PHY. | ||
18 | 19 | ||
19 | Example: | 20 | Example: |
20 | 21 | ||
@@ -25,4 +26,5 @@ ethernet@83fec000 { | |||
25 | phy-mode = "mii"; | 26 | phy-mode = "mii"; |
26 | phy-reset-gpios = <&gpio2 14 0>; /* GPIO2_14 */ | 27 | phy-reset-gpios = <&gpio2 14 0>; /* GPIO2_14 */ |
27 | local-mac-address = [00 04 9F 01 1B B9]; | 28 | local-mac-address = [00 04 9F 01 1B B9]; |
29 | phy-supply = <®_fec_supply>; | ||
28 | }; | 30 | }; |
diff --git a/Documentation/devicetree/bindings/net/smsc-lan91c111.txt b/Documentation/devicetree/bindings/net/smsc-lan91c111.txt index 953049b4248a..5a41a8658daa 100644 --- a/Documentation/devicetree/bindings/net/smsc-lan91c111.txt +++ b/Documentation/devicetree/bindings/net/smsc-lan91c111.txt | |||
@@ -8,3 +8,7 @@ Required properties: | |||
8 | Optional properties: | 8 | Optional properties: |
9 | - phy-device : phandle to Ethernet phy | 9 | - phy-device : phandle to Ethernet phy |
10 | - local-mac-address : Ethernet mac address to use | 10 | - local-mac-address : Ethernet mac address to use |
11 | - reg-io-width : Mask of sizes (in bytes) of the IO accesses that | ||
12 | are supported on the device. Valid value for SMSC LAN91c111 are | ||
13 | 1, 2 or 4. If it's omitted or invalid, the size would be 2 meaning | ||
14 | 16-bit access only. | ||
diff --git a/Documentation/devicetree/bindings/rng/qcom,prng.txt b/Documentation/devicetree/bindings/rng/qcom,prng.txt new file mode 100644 index 000000000000..8e5853c2879b --- /dev/null +++ b/Documentation/devicetree/bindings/rng/qcom,prng.txt | |||
@@ -0,0 +1,17 @@ | |||
1 | Qualcomm MSM pseudo random number generator. | ||
2 | |||
3 | Required properties: | ||
4 | |||
5 | - compatible : should be "qcom,prng" | ||
6 | - reg : specifies base physical address and size of the registers map | ||
7 | - clocks : phandle to clock-controller plus clock-specifier pair | ||
8 | - clock-names : "core" clocks all registers, FIFO and circuits in PRNG IP block | ||
9 | |||
10 | Example: | ||
11 | |||
12 | rng@f9bff000 { | ||
13 | compatible = "qcom,prng"; | ||
14 | reg = <0xf9bff000 0x200>; | ||
15 | clocks = <&clock GCC_PRNG_AHB_CLK>; | ||
16 | clock-names = "core"; | ||
17 | }; | ||
diff --git a/Documentation/devicetree/bindings/spi/nvidia,tegra20-spi.txt b/Documentation/devicetree/bindings/spi/nvidia,tegra20-spi.txt deleted file mode 100644 index 6b9e51896693..000000000000 --- a/Documentation/devicetree/bindings/spi/nvidia,tegra20-spi.txt +++ /dev/null | |||
@@ -1,5 +0,0 @@ | |||
1 | NVIDIA Tegra 2 SPI device | ||
2 | |||
3 | Required properties: | ||
4 | - compatible : should be "nvidia,tegra20-spi". | ||
5 | - gpios : should specify GPIOs used for chipselect. | ||
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt index ce95ed1c6d3e..edbb8d88c85e 100644 --- a/Documentation/devicetree/bindings/vendor-prefixes.txt +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt | |||
@@ -32,12 +32,14 @@ est ESTeem Wireless Modems | |||
32 | fsl Freescale Semiconductor | 32 | fsl Freescale Semiconductor |
33 | GEFanuc GE Fanuc Intelligent Platforms Embedded Systems, Inc. | 33 | GEFanuc GE Fanuc Intelligent Platforms Embedded Systems, Inc. |
34 | gef GE Fanuc Intelligent Platforms Embedded Systems, Inc. | 34 | gef GE Fanuc Intelligent Platforms Embedded Systems, Inc. |
35 | gmt Global Mixed-mode Technology, Inc. | ||
35 | hisilicon Hisilicon Limited. | 36 | hisilicon Hisilicon Limited. |
36 | hp Hewlett Packard | 37 | hp Hewlett Packard |
37 | ibm International Business Machines (IBM) | 38 | ibm International Business Machines (IBM) |
38 | idt Integrated Device Technologies, Inc. | 39 | idt Integrated Device Technologies, Inc. |
39 | img Imagination Technologies Ltd. | 40 | img Imagination Technologies Ltd. |
40 | intercontrol Inter Control Group | 41 | intercontrol Inter Control Group |
42 | lg LG Corporation | ||
41 | linux Linux-specific binding | 43 | linux Linux-specific binding |
42 | lsi LSI Corp. (LSI Logic) | 44 | lsi LSI Corp. (LSI Logic) |
43 | marvell Marvell Technology Group Ltd. | 45 | marvell Marvell Technology Group Ltd. |
diff --git a/Documentation/gpio/00-INDEX b/Documentation/gpio/00-INDEX new file mode 100644 index 000000000000..1de43ae46ae6 --- /dev/null +++ b/Documentation/gpio/00-INDEX | |||
@@ -0,0 +1,14 @@ | |||
1 | 00-INDEX | ||
2 | - This file | ||
3 | gpio.txt | ||
4 | - Introduction to GPIOs and their kernel interfaces | ||
5 | consumer.txt | ||
6 | - How to obtain and use GPIOs in a driver | ||
7 | driver.txt | ||
8 | - How to write a GPIO driver | ||
9 | board.txt | ||
10 | - How to assign GPIOs to a consumer device and a function | ||
11 | sysfs.txt | ||
12 | - Information about the GPIO sysfs interface | ||
13 | gpio-legacy.txt | ||
14 | - Historical documentation of the deprecated GPIO integer interface | ||
diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt new file mode 100644 index 000000000000..0d03506f2cc5 --- /dev/null +++ b/Documentation/gpio/board.txt | |||
@@ -0,0 +1,115 @@ | |||
1 | GPIO Mappings | ||
2 | ============= | ||
3 | |||
4 | This document explains how GPIOs can be assigned to given devices and functions. | ||
5 | Note that it only applies to the new descriptor-based interface. For a | ||
6 | description of the deprecated integer-based GPIO interface please refer to | ||
7 | gpio-legacy.txt (actually, there is no real mapping possible with the old | ||
8 | interface; you just fetch an integer from somewhere and request the | ||
9 | corresponding GPIO. | ||
10 | |||
11 | Platforms that make use of GPIOs must select ARCH_REQUIRE_GPIOLIB (if GPIO usage | ||
12 | is mandatory) or ARCH_WANT_OPTIONAL_GPIOLIB (if GPIO support can be omitted) in | ||
13 | their Kconfig. Then, how GPIOs are mapped depends on what the platform uses to | ||
14 | describe its hardware layout. Currently, mappings can be defined through device | ||
15 | tree, ACPI, and platform data. | ||
16 | |||
17 | Device Tree | ||
18 | ----------- | ||
19 | GPIOs can easily be mapped to devices and functions in the device tree. The | ||
20 | exact way to do it depends on the GPIO controller providing the GPIOs, see the | ||
21 | device tree bindings for your controller. | ||
22 | |||
23 | GPIOs mappings are defined in the consumer device's node, in a property named | ||
24 | <function>-gpios, where <function> is the function the driver will request | ||
25 | through gpiod_get(). For example: | ||
26 | |||
27 | foo_device { | ||
28 | compatible = "acme,foo"; | ||
29 | ... | ||
30 | led-gpios = <&gpio 15 GPIO_ACTIVE_HIGH>, /* red */ | ||
31 | <&gpio 16 GPIO_ACTIVE_HIGH>, /* green */ | ||
32 | <&gpio 17 GPIO_ACTIVE_HIGH>; /* blue */ | ||
33 | |||
34 | power-gpio = <&gpio 1 GPIO_ACTIVE_LOW>; | ||
35 | }; | ||
36 | |||
37 | This property will make GPIOs 15, 16 and 17 available to the driver under the | ||
38 | "led" function, and GPIO 1 as the "power" GPIO: | ||
39 | |||
40 | struct gpio_desc *red, *green, *blue, *power; | ||
41 | |||
42 | red = gpiod_get_index(dev, "led", 0); | ||
43 | green = gpiod_get_index(dev, "led", 1); | ||
44 | blue = gpiod_get_index(dev, "led", 2); | ||
45 | |||
46 | power = gpiod_get(dev, "power"); | ||
47 | |||
48 | The led GPIOs will be active-high, while the power GPIO will be active-low (i.e. | ||
49 | gpiod_is_active_low(power) will be true). | ||
50 | |||
51 | ACPI | ||
52 | ---- | ||
53 | ACPI does not support function names for GPIOs. Therefore, only the "idx" | ||
54 | argument of gpiod_get_index() is useful to discriminate between GPIOs assigned | ||
55 | to a device. The "con_id" argument can still be set for debugging purposes (it | ||
56 | will appear under error messages as well as debug and sysfs nodes). | ||
57 | |||
58 | Platform Data | ||
59 | ------------- | ||
60 | Finally, GPIOs can be bound to devices and functions using platform data. Board | ||
61 | files that desire to do so need to include the following header: | ||
62 | |||
63 | #include <linux/gpio/driver.h> | ||
64 | |||
65 | GPIOs are mapped by the means of tables of lookups, containing instances of the | ||
66 | gpiod_lookup structure. Two macros are defined to help declaring such mappings: | ||
67 | |||
68 | GPIO_LOOKUP(chip_label, chip_hwnum, dev_id, con_id, flags) | ||
69 | GPIO_LOOKUP_IDX(chip_label, chip_hwnum, dev_id, con_id, idx, flags) | ||
70 | |||
71 | where | ||
72 | |||
73 | - chip_label is the label of the gpiod_chip instance providing the GPIO | ||
74 | - chip_hwnum is the hardware number of the GPIO within the chip | ||
75 | - dev_id is the identifier of the device that will make use of this GPIO. If | ||
76 | NULL, the GPIO will be available to all devices. | ||
77 | - con_id is the name of the GPIO function from the device point of view. It | ||
78 | can be NULL. | ||
79 | - idx is the index of the GPIO within the function. | ||
80 | - flags is defined to specify the following properties: | ||
81 | * GPIOF_ACTIVE_LOW - to configure the GPIO as active-low | ||
82 | * GPIOF_OPEN_DRAIN - GPIO pin is open drain type. | ||
83 | * GPIOF_OPEN_SOURCE - GPIO pin is open source type. | ||
84 | |||
85 | In the future, these flags might be extended to support more properties. | ||
86 | |||
87 | Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0. | ||
88 | |||
89 | A lookup table can then be defined as follows: | ||
90 | |||
91 | struct gpiod_lookup gpios_table[] = { | ||
92 | GPIO_LOOKUP_IDX("gpio.0", 15, "foo.0", "led", 0, GPIO_ACTIVE_HIGH), | ||
93 | GPIO_LOOKUP_IDX("gpio.0", 16, "foo.0", "led", 1, GPIO_ACTIVE_HIGH), | ||
94 | GPIO_LOOKUP_IDX("gpio.0", 17, "foo.0", "led", 2, GPIO_ACTIVE_HIGH), | ||
95 | GPIO_LOOKUP("gpio.0", 1, "foo.0", "power", GPIO_ACTIVE_LOW), | ||
96 | }; | ||
97 | |||
98 | And the table can be added by the board code as follows: | ||
99 | |||
100 | gpiod_add_table(gpios_table, ARRAY_SIZE(gpios_table)); | ||
101 | |||
102 | The driver controlling "foo.0" will then be able to obtain its GPIOs as follows: | ||
103 | |||
104 | struct gpio_desc *red, *green, *blue, *power; | ||
105 | |||
106 | red = gpiod_get_index(dev, "led", 0); | ||
107 | green = gpiod_get_index(dev, "led", 1); | ||
108 | blue = gpiod_get_index(dev, "led", 2); | ||
109 | |||
110 | power = gpiod_get(dev, "power"); | ||
111 | gpiod_direction_output(power, 1); | ||
112 | |||
113 | Since the "power" GPIO is mapped as active-low, its actual signal will be 0 | ||
114 | after this code. Contrary to the legacy integer GPIO interface, the active-low | ||
115 | property is handled during mapping and is thus transparent to GPIO consumers. | ||
diff --git a/Documentation/gpio/consumer.txt b/Documentation/gpio/consumer.txt new file mode 100644 index 000000000000..07c74a3765a0 --- /dev/null +++ b/Documentation/gpio/consumer.txt | |||
@@ -0,0 +1,197 @@ | |||
1 | GPIO Descriptor Consumer Interface | ||
2 | ================================== | ||
3 | |||
4 | This document describes the consumer interface of the GPIO framework. Note that | ||
5 | it describes the new descriptor-based interface. For a description of the | ||
6 | deprecated integer-based GPIO interface please refer to gpio-legacy.txt. | ||
7 | |||
8 | |||
9 | Guidelines for GPIOs consumers | ||
10 | ============================== | ||
11 | |||
12 | Drivers that can't work without standard GPIO calls should have Kconfig entries | ||
13 | that depend on GPIOLIB. The functions that allow a driver to obtain and use | ||
14 | GPIOs are available by including the following file: | ||
15 | |||
16 | #include <linux/gpio/consumer.h> | ||
17 | |||
18 | All the functions that work with the descriptor-based GPIO interface are | ||
19 | prefixed with gpiod_. The gpio_ prefix is used for the legacy interface. No | ||
20 | other function in the kernel should use these prefixes. | ||
21 | |||
22 | |||
23 | Obtaining and Disposing GPIOs | ||
24 | ============================= | ||
25 | |||
26 | With the descriptor-based interface, GPIOs are identified with an opaque, | ||
27 | non-forgeable handler that must be obtained through a call to one of the | ||
28 | gpiod_get() functions. Like many other kernel subsystems, gpiod_get() takes the | ||
29 | device that will use the GPIO and the function the requested GPIO is supposed to | ||
30 | fulfill: | ||
31 | |||
32 | struct gpio_desc *gpiod_get(struct device *dev, const char *con_id) | ||
33 | |||
34 | If a function is implemented by using several GPIOs together (e.g. a simple LED | ||
35 | device that displays digits), an additional index argument can be specified: | ||
36 | |||
37 | struct gpio_desc *gpiod_get_index(struct device *dev, | ||
38 | const char *con_id, unsigned int idx) | ||
39 | |||
40 | Both functions return either a valid GPIO descriptor, or an error code checkable | ||
41 | with IS_ERR(). They will never return a NULL pointer. | ||
42 | |||
43 | Device-managed variants of these functions are also defined: | ||
44 | |||
45 | struct gpio_desc *devm_gpiod_get(struct device *dev, const char *con_id) | ||
46 | |||
47 | struct gpio_desc *devm_gpiod_get_index(struct device *dev, | ||
48 | const char *con_id, | ||
49 | unsigned int idx) | ||
50 | |||
51 | A GPIO descriptor can be disposed of using the gpiod_put() function: | ||
52 | |||
53 | void gpiod_put(struct gpio_desc *desc) | ||
54 | |||
55 | It is strictly forbidden to use a descriptor after calling this function. The | ||
56 | device-managed variant is, unsurprisingly: | ||
57 | |||
58 | void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) | ||
59 | |||
60 | |||
61 | Using GPIOs | ||
62 | =========== | ||
63 | |||
64 | Setting Direction | ||
65 | ----------------- | ||
66 | The first thing a driver must do with a GPIO is setting its direction. This is | ||
67 | done by invoking one of the gpiod_direction_*() functions: | ||
68 | |||
69 | int gpiod_direction_input(struct gpio_desc *desc) | ||
70 | int gpiod_direction_output(struct gpio_desc *desc, int value) | ||
71 | |||
72 | The return value is zero for success, else a negative errno. It should be | ||
73 | checked, since the get/set calls don't return errors and since misconfiguration | ||
74 | is possible. You should normally issue these calls from a task context. However, | ||
75 | for spinlock-safe GPIOs it is OK to use them before tasking is enabled, as part | ||
76 | of early board setup. | ||
77 | |||
78 | For output GPIOs, the value provided becomes the initial output value. This | ||
79 | helps avoid signal glitching during system startup. | ||
80 | |||
81 | A driver can also query the current direction of a GPIO: | ||
82 | |||
83 | int gpiod_get_direction(const struct gpio_desc *desc) | ||
84 | |||
85 | This function will return either GPIOF_DIR_IN or GPIOF_DIR_OUT. | ||
86 | |||
87 | Be aware that there is no default direction for GPIOs. Therefore, **using a GPIO | ||
88 | without setting its direction first is illegal and will result in undefined | ||
89 | behavior!** | ||
90 | |||
91 | |||
92 | Spinlock-Safe GPIO Access | ||
93 | ------------------------- | ||
94 | Most GPIO controllers can be accessed with memory read/write instructions. Those | ||
95 | don't need to sleep, and can safely be done from inside hard (non-threaded) IRQ | ||
96 | handlers and similar contexts. | ||
97 | |||
98 | Use the following calls to access GPIOs from an atomic context: | ||
99 | |||
100 | int gpiod_get_value(const struct gpio_desc *desc); | ||
101 | void gpiod_set_value(struct gpio_desc *desc, int value); | ||
102 | |||
103 | The values are boolean, zero for low, nonzero for high. When reading the value | ||
104 | of an output pin, the value returned should be what's seen on the pin. That | ||
105 | won't always match the specified output value, because of issues including | ||
106 | open-drain signaling and output latencies. | ||
107 | |||
108 | The get/set calls do not return errors because "invalid GPIO" should have been | ||
109 | reported earlier from gpiod_direction_*(). However, note that not all platforms | ||
110 | can read the value of output pins; those that can't should always return zero. | ||
111 | Also, using these calls for GPIOs that can't safely be accessed without sleeping | ||
112 | (see below) is an error. | ||
113 | |||
114 | |||
115 | GPIO Access That May Sleep | ||
116 | -------------------------- | ||
117 | Some GPIO controllers must be accessed using message based buses like I2C or | ||
118 | SPI. Commands to read or write those GPIO values require waiting to get to the | ||
119 | head of a queue to transmit a command and get its response. This requires | ||
120 | sleeping, which can't be done from inside IRQ handlers. | ||
121 | |||
122 | Platforms that support this type of GPIO distinguish them from other GPIOs by | ||
123 | returning nonzero from this call: | ||
124 | |||
125 | int gpiod_cansleep(const struct gpio_desc *desc) | ||
126 | |||
127 | To access such GPIOs, a different set of accessors is defined: | ||
128 | |||
129 | int gpiod_get_value_cansleep(const struct gpio_desc *desc) | ||
130 | void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) | ||
131 | |||
132 | Accessing such GPIOs requires a context which may sleep, for example a threaded | ||
133 | IRQ handler, and those accessors must be used instead of spinlock-safe | ||
134 | accessors without the cansleep() name suffix. | ||
135 | |||
136 | Other than the fact that these accessors might sleep, and will work on GPIOs | ||
137 | that can't be accessed from hardIRQ handlers, these calls act the same as the | ||
138 | spinlock-safe calls. | ||
139 | |||
140 | |||
141 | Active-low State and Raw GPIO Values | ||
142 | ------------------------------------ | ||
143 | Device drivers like to manage the logical state of a GPIO, i.e. the value their | ||
144 | device will actually receive, no matter what lies between it and the GPIO line. | ||
145 | In some cases, it might make sense to control the actual GPIO line value. The | ||
146 | following set of calls ignore the active-low property of a GPIO and work on the | ||
147 | raw line value: | ||
148 | |||
149 | int gpiod_get_raw_value(const struct gpio_desc *desc) | ||
150 | void gpiod_set_raw_value(struct gpio_desc *desc, int value) | ||
151 | int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) | ||
152 | void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) | ||
153 | |||
154 | The active-low state of a GPIO can also be queried using the following call: | ||
155 | |||
156 | int gpiod_is_active_low(const struct gpio_desc *desc) | ||
157 | |||
158 | Note that these functions should only be used with great moderation ; a driver | ||
159 | should not have to care about the physical line level. | ||
160 | |||
161 | GPIOs mapped to IRQs | ||
162 | -------------------- | ||
163 | GPIO lines can quite often be used as IRQs. You can get the IRQ number | ||
164 | corresponding to a given GPIO using the following call: | ||
165 | |||
166 | int gpiod_to_irq(const struct gpio_desc *desc) | ||
167 | |||
168 | It will return an IRQ number, or an negative errno code if the mapping can't be | ||
169 | done (most likely because that particular GPIO cannot be used as IRQ). It is an | ||
170 | unchecked error to use a GPIO that wasn't set up as an input using | ||
171 | gpiod_direction_input(), or to use an IRQ number that didn't originally come | ||
172 | from gpiod_to_irq(). gpiod_to_irq() is not allowed to sleep. | ||
173 | |||
174 | Non-error values returned from gpiod_to_irq() can be passed to request_irq() or | ||
175 | free_irq(). They will often be stored into IRQ resources for platform devices, | ||
176 | by the board-specific initialization code. Note that IRQ trigger options are | ||
177 | part of the IRQ interface, e.g. IRQF_TRIGGER_FALLING, as are system wakeup | ||
178 | capabilities. | ||
179 | |||
180 | |||
181 | Interacting With the Legacy GPIO Subsystem | ||
182 | ========================================== | ||
183 | Many kernel subsystems still handle GPIOs using the legacy integer-based | ||
184 | interface. Although it is strongly encouraged to upgrade them to the safer | ||
185 | descriptor-based API, the following two functions allow you to convert a GPIO | ||
186 | descriptor into the GPIO integer namespace and vice-versa: | ||
187 | |||
188 | int desc_to_gpio(const struct gpio_desc *desc) | ||
189 | struct gpio_desc *gpio_to_desc(unsigned gpio) | ||
190 | |||
191 | The GPIO number returned by desc_to_gpio() can be safely used as long as the | ||
192 | GPIO descriptor has not been freed. All the same, a GPIO number passed to | ||
193 | gpio_to_desc() must have been properly acquired, and usage of the returned GPIO | ||
194 | descriptor is only possible after the GPIO number has been released. | ||
195 | |||
196 | Freeing a GPIO obtained by one API with the other API is forbidden and an | ||
197 | unchecked error. | ||
diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt new file mode 100644 index 000000000000..9da0bfa74781 --- /dev/null +++ b/Documentation/gpio/driver.txt | |||
@@ -0,0 +1,75 @@ | |||
1 | GPIO Descriptor Driver Interface | ||
2 | ================================ | ||
3 | |||
4 | This document serves as a guide for GPIO chip drivers writers. Note that it | ||
5 | describes the new descriptor-based interface. For a description of the | ||
6 | deprecated integer-based GPIO interface please refer to gpio-legacy.txt. | ||
7 | |||
8 | Each GPIO controller driver needs to include the following header, which defines | ||
9 | the structures used to define a GPIO driver: | ||
10 | |||
11 | #include <linux/gpio/driver.h> | ||
12 | |||
13 | |||
14 | Internal Representation of GPIOs | ||
15 | ================================ | ||
16 | |||
17 | Inside a GPIO driver, individual GPIOs are identified by their hardware number, | ||
18 | which is a unique number between 0 and n, n being the number of GPIOs managed by | ||
19 | the chip. This number is purely internal: the hardware number of a particular | ||
20 | GPIO descriptor is never made visible outside of the driver. | ||
21 | |||
22 | On top of this internal number, each GPIO also need to have a global number in | ||
23 | the integer GPIO namespace so that it can be used with the legacy GPIO | ||
24 | interface. Each chip must thus have a "base" number (which can be automatically | ||
25 | assigned), and for each GPIO the global number will be (base + hardware number). | ||
26 | Although the integer representation is considered deprecated, it still has many | ||
27 | users and thus needs to be maintained. | ||
28 | |||
29 | So for example one platform could use numbers 32-159 for GPIOs, with a | ||
30 | controller defining 128 GPIOs at a "base" of 32 ; while another platform uses | ||
31 | numbers 0..63 with one set of GPIO controllers, 64-79 with another type of GPIO | ||
32 | controller, and on one particular board 80-95 with an FPGA. The numbers need not | ||
33 | be contiguous; either of those platforms could also use numbers 2000-2063 to | ||
34 | identify GPIOs in a bank of I2C GPIO expanders. | ||
35 | |||
36 | |||
37 | Controller Drivers: gpio_chip | ||
38 | ============================= | ||
39 | |||
40 | In the gpiolib framework each GPIO controller is packaged as a "struct | ||
41 | gpio_chip" (see linux/gpio/driver.h for its complete definition) with members | ||
42 | common to each controller of that type: | ||
43 | |||
44 | - methods to establish GPIO direction | ||
45 | - methods used to access GPIO values | ||
46 | - method to return the IRQ number associated to a given GPIO | ||
47 | - flag saying whether calls to its methods may sleep | ||
48 | - optional debugfs dump method (showing extra state like pullup config) | ||
49 | - optional base number (will be automatically assigned if omitted) | ||
50 | - label for diagnostics and GPIOs mapping using platform data | ||
51 | |||
52 | The code implementing a gpio_chip should support multiple instances of the | ||
53 | controller, possibly using the driver model. That code will configure each | ||
54 | gpio_chip and issue gpiochip_add(). Removing a GPIO controller should be rare; | ||
55 | use gpiochip_remove() when it is unavoidable. | ||
56 | |||
57 | Most often a gpio_chip is part of an instance-specific structure with state not | ||
58 | exposed by the GPIO interfaces, such as addressing, power management, and more. | ||
59 | Chips such as codecs will have complex non-GPIO state. | ||
60 | |||
61 | Any debugfs dump method should normally ignore signals which haven't been | ||
62 | requested as GPIOs. They can use gpiochip_is_requested(), which returns either | ||
63 | NULL or the label associated with that GPIO when it was requested. | ||
64 | |||
65 | Locking IRQ usage | ||
66 | ----------------- | ||
67 | Input GPIOs can be used as IRQ signals. When this happens, a driver is requested | ||
68 | to mark the GPIO as being used as an IRQ: | ||
69 | |||
70 | int gpiod_lock_as_irq(struct gpio_desc *desc) | ||
71 | |||
72 | This will prevent the use of non-irq related GPIO APIs until the GPIO IRQ lock | ||
73 | is released: | ||
74 | |||
75 | void gpiod_unlock_as_irq(struct gpio_desc *desc) | ||
diff --git a/Documentation/gpio.txt b/Documentation/gpio/gpio-legacy.txt index 6f83fa965b4b..6f83fa965b4b 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio/gpio-legacy.txt | |||
diff --git a/Documentation/gpio/gpio.txt b/Documentation/gpio/gpio.txt new file mode 100644 index 000000000000..cd9b356e88cd --- /dev/null +++ b/Documentation/gpio/gpio.txt | |||
@@ -0,0 +1,119 @@ | |||
1 | GPIO Interfaces | ||
2 | =============== | ||
3 | |||
4 | The documents in this directory give detailed instructions on how to access | ||
5 | GPIOs in drivers, and how to write a driver for a device that provides GPIOs | ||
6 | itself. | ||
7 | |||
8 | Due to the history of GPIO interfaces in the kernel, there are two different | ||
9 | ways to obtain and use GPIOs: | ||
10 | |||
11 | - The descriptor-based interface is the preferred way to manipulate GPIOs, | ||
12 | and is described by all the files in this directory excepted gpio-legacy.txt. | ||
13 | - The legacy integer-based interface which is considered deprecated (but still | ||
14 | usable for compatibility reasons) is documented in gpio-legacy.txt. | ||
15 | |||
16 | The remainder of this document applies to the new descriptor-based interface. | ||
17 | gpio-legacy.txt contains the same information applied to the legacy | ||
18 | integer-based interface. | ||
19 | |||
20 | |||
21 | What is a GPIO? | ||
22 | =============== | ||
23 | |||
24 | A "General Purpose Input/Output" (GPIO) is a flexible software-controlled | ||
25 | digital signal. They are provided from many kinds of chip, and are familiar | ||
26 | to Linux developers working with embedded and custom hardware. Each GPIO | ||
27 | represents a bit connected to a particular pin, or "ball" on Ball Grid Array | ||
28 | (BGA) packages. Board schematics show which external hardware connects to | ||
29 | which GPIOs. Drivers can be written generically, so that board setup code | ||
30 | passes such pin configuration data to drivers. | ||
31 | |||
32 | System-on-Chip (SOC) processors heavily rely on GPIOs. In some cases, every | ||
33 | non-dedicated pin can be configured as a GPIO; and most chips have at least | ||
34 | several dozen of them. Programmable logic devices (like FPGAs) can easily | ||
35 | provide GPIOs; multifunction chips like power managers, and audio codecs | ||
36 | often have a few such pins to help with pin scarcity on SOCs; and there are | ||
37 | also "GPIO Expander" chips that connect using the I2C or SPI serial buses. | ||
38 | Most PC southbridges have a few dozen GPIO-capable pins (with only the BIOS | ||
39 | firmware knowing how they're used). | ||
40 | |||
41 | The exact capabilities of GPIOs vary between systems. Common options: | ||
42 | |||
43 | - Output values are writable (high=1, low=0). Some chips also have | ||
44 | options about how that value is driven, so that for example only one | ||
45 | value might be driven, supporting "wire-OR" and similar schemes for the | ||
46 | other value (notably, "open drain" signaling). | ||
47 | |||
48 | - Input values are likewise readable (1, 0). Some chips support readback | ||
49 | of pins configured as "output", which is very useful in such "wire-OR" | ||
50 | cases (to support bidirectional signaling). GPIO controllers may have | ||
51 | input de-glitch/debounce logic, sometimes with software controls. | ||
52 | |||
53 | - Inputs can often be used as IRQ signals, often edge triggered but | ||
54 | sometimes level triggered. Such IRQs may be configurable as system | ||
55 | wakeup events, to wake the system from a low power state. | ||
56 | |||
57 | - Usually a GPIO will be configurable as either input or output, as needed | ||
58 | by different product boards; single direction ones exist too. | ||
59 | |||
60 | - Most GPIOs can be accessed while holding spinlocks, but those accessed | ||
61 | through a serial bus normally can't. Some systems support both types. | ||
62 | |||
63 | On a given board each GPIO is used for one specific purpose like monitoring | ||
64 | MMC/SD card insertion/removal, detecting card write-protect status, driving | ||
65 | a LED, configuring a transceiver, bit-banging a serial bus, poking a hardware | ||
66 | watchdog, sensing a switch, and so on. | ||
67 | |||
68 | |||
69 | Common GPIO Properties | ||
70 | ====================== | ||
71 | |||
72 | These properties are met through all the other documents of the GPIO interface | ||
73 | and it is useful to understand them, especially if you need to define GPIO | ||
74 | mappings. | ||
75 | |||
76 | Active-High and Active-Low | ||
77 | -------------------------- | ||
78 | It is natural to assume that a GPIO is "active" when its output signal is 1 | ||
79 | ("high"), and inactive when it is 0 ("low"). However in practice the signal of a | ||
80 | GPIO may be inverted before is reaches its destination, or a device could decide | ||
81 | to have different conventions about what "active" means. Such decisions should | ||
82 | be transparent to device drivers, therefore it is possible to define a GPIO as | ||
83 | being either active-high ("1" means "active", the default) or active-low ("0" | ||
84 | means "active") so that drivers only need to worry about the logical signal and | ||
85 | not about what happens at the line level. | ||
86 | |||
87 | Open Drain and Open Source | ||
88 | -------------------------- | ||
89 | Sometimes shared signals need to use "open drain" (where only the low signal | ||
90 | level is actually driven), or "open source" (where only the high signal level is | ||
91 | driven) signaling. That term applies to CMOS transistors; "open collector" is | ||
92 | used for TTL. A pullup or pulldown resistor causes the high or low signal level. | ||
93 | This is sometimes called a "wire-AND"; or more practically, from the negative | ||
94 | logic (low=true) perspective this is a "wire-OR". | ||
95 | |||
96 | One common example of an open drain signal is a shared active-low IRQ line. | ||
97 | Also, bidirectional data bus signals sometimes use open drain signals. | ||
98 | |||
99 | Some GPIO controllers directly support open drain and open source outputs; many | ||
100 | don't. When you need open drain signaling but your hardware doesn't directly | ||
101 | support it, there's a common idiom you can use to emulate it with any GPIO pin | ||
102 | that can be used as either an input or an output: | ||
103 | |||
104 | LOW: gpiod_direction_output(gpio, 0) ... this drives the signal and overrides | ||
105 | the pullup. | ||
106 | |||
107 | HIGH: gpiod_direction_input(gpio) ... this turns off the output, so the pullup | ||
108 | (or some other device) controls the signal. | ||
109 | |||
110 | The same logic can be applied to emulate open source signaling, by driving the | ||
111 | high signal and configuring the GPIO as input for low. This open drain/open | ||
112 | source emulation can be handled transparently by the GPIO framework. | ||
113 | |||
114 | If you are "driving" the signal high but gpiod_get_value(gpio) reports a low | ||
115 | value (after the appropriate rise time passes), you know some other component is | ||
116 | driving the shared signal low. That's not necessarily an error. As one common | ||
117 | example, that's how I2C clocks are stretched: a slave that needs a slower clock | ||
118 | delays the rising edge of SCK, and the I2C master adjusts its signaling rate | ||
119 | accordingly. | ||
diff --git a/Documentation/gpio/sysfs.txt b/Documentation/gpio/sysfs.txt new file mode 100644 index 000000000000..c2c3a97f8ff7 --- /dev/null +++ b/Documentation/gpio/sysfs.txt | |||
@@ -0,0 +1,155 @@ | |||
1 | GPIO Sysfs Interface for Userspace | ||
2 | ================================== | ||
3 | |||
4 | Platforms which use the "gpiolib" implementors framework may choose to | ||
5 | configure a sysfs user interface to GPIOs. This is different from the | ||
6 | debugfs interface, since it provides control over GPIO direction and | ||
7 | value instead of just showing a gpio state summary. Plus, it could be | ||
8 | present on production systems without debugging support. | ||
9 | |||
10 | Given appropriate hardware documentation for the system, userspace could | ||
11 | know for example that GPIO #23 controls the write protect line used to | ||
12 | protect boot loader segments in flash memory. System upgrade procedures | ||
13 | may need to temporarily remove that protection, first importing a GPIO, | ||
14 | then changing its output state, then updating the code before re-enabling | ||
15 | the write protection. In normal use, GPIO #23 would never be touched, | ||
16 | and the kernel would have no need to know about it. | ||
17 | |||
18 | Again depending on appropriate hardware documentation, on some systems | ||
19 | userspace GPIO can be used to determine system configuration data that | ||
20 | standard kernels won't know about. And for some tasks, simple userspace | ||
21 | GPIO drivers could be all that the system really needs. | ||
22 | |||
23 | Note that standard kernel drivers exist for common "LEDs and Buttons" | ||
24 | GPIO tasks: "leds-gpio" and "gpio_keys", respectively. Use those | ||
25 | instead of talking directly to the GPIOs; they integrate with kernel | ||
26 | frameworks better than your userspace code could. | ||
27 | |||
28 | |||
29 | Paths in Sysfs | ||
30 | -------------- | ||
31 | There are three kinds of entry in /sys/class/gpio: | ||
32 | |||
33 | - Control interfaces used to get userspace control over GPIOs; | ||
34 | |||
35 | - GPIOs themselves; and | ||
36 | |||
37 | - GPIO controllers ("gpio_chip" instances). | ||
38 | |||
39 | That's in addition to standard files including the "device" symlink. | ||
40 | |||
41 | The control interfaces are write-only: | ||
42 | |||
43 | /sys/class/gpio/ | ||
44 | |||
45 | "export" ... Userspace may ask the kernel to export control of | ||
46 | a GPIO to userspace by writing its number to this file. | ||
47 | |||
48 | Example: "echo 19 > export" will create a "gpio19" node | ||
49 | for GPIO #19, if that's not requested by kernel code. | ||
50 | |||
51 | "unexport" ... Reverses the effect of exporting to userspace. | ||
52 | |||
53 | Example: "echo 19 > unexport" will remove a "gpio19" | ||
54 | node exported using the "export" file. | ||
55 | |||
56 | GPIO signals have paths like /sys/class/gpio/gpio42/ (for GPIO #42) | ||
57 | and have the following read/write attributes: | ||
58 | |||
59 | /sys/class/gpio/gpioN/ | ||
60 | |||
61 | "direction" ... reads as either "in" or "out". This value may | ||
62 | normally be written. Writing as "out" defaults to | ||
63 | initializing the value as low. To ensure glitch free | ||
64 | operation, values "low" and "high" may be written to | ||
65 | configure the GPIO as an output with that initial value. | ||
66 | |||
67 | Note that this attribute *will not exist* if the kernel | ||
68 | doesn't support changing the direction of a GPIO, or | ||
69 | it was exported by kernel code that didn't explicitly | ||
70 | allow userspace to reconfigure this GPIO's direction. | ||
71 | |||
72 | "value" ... reads as either 0 (low) or 1 (high). If the GPIO | ||
73 | is configured as an output, this value may be written; | ||
74 | any nonzero value is treated as high. | ||
75 | |||
76 | If the pin can be configured as interrupt-generating interrupt | ||
77 | and if it has been configured to generate interrupts (see the | ||
78 | description of "edge"), you can poll(2) on that file and | ||
79 | poll(2) will return whenever the interrupt was triggered. If | ||
80 | you use poll(2), set the events POLLPRI and POLLERR. If you | ||
81 | use select(2), set the file descriptor in exceptfds. After | ||
82 | poll(2) returns, either lseek(2) to the beginning of the sysfs | ||
83 | file and read the new value or close the file and re-open it | ||
84 | to read the value. | ||
85 | |||
86 | "edge" ... reads as either "none", "rising", "falling", or | ||
87 | "both". Write these strings to select the signal edge(s) | ||
88 | that will make poll(2) on the "value" file return. | ||
89 | |||
90 | This file exists only if the pin can be configured as an | ||
91 | interrupt generating input pin. | ||
92 | |||
93 | "active_low" ... reads as either 0 (false) or 1 (true). Write | ||
94 | any nonzero value to invert the value attribute both | ||
95 | for reading and writing. Existing and subsequent | ||
96 | poll(2) support configuration via the edge attribute | ||
97 | for "rising" and "falling" edges will follow this | ||
98 | setting. | ||
99 | |||
100 | GPIO controllers have paths like /sys/class/gpio/gpiochip42/ (for the | ||
101 | controller implementing GPIOs starting at #42) and have the following | ||
102 | read-only attributes: | ||
103 | |||
104 | /sys/class/gpio/gpiochipN/ | ||
105 | |||
106 | "base" ... same as N, the first GPIO managed by this chip | ||
107 | |||
108 | "label" ... provided for diagnostics (not always unique) | ||
109 | |||
110 | "ngpio" ... how many GPIOs this manges (N to N + ngpio - 1) | ||
111 | |||
112 | Board documentation should in most cases cover what GPIOs are used for | ||
113 | what purposes. However, those numbers are not always stable; GPIOs on | ||
114 | a daughtercard might be different depending on the base board being used, | ||
115 | or other cards in the stack. In such cases, you may need to use the | ||
116 | gpiochip nodes (possibly in conjunction with schematics) to determine | ||
117 | the correct GPIO number to use for a given signal. | ||
118 | |||
119 | |||
120 | Exporting from Kernel code | ||
121 | -------------------------- | ||
122 | Kernel code can explicitly manage exports of GPIOs which have already been | ||
123 | requested using gpio_request(): | ||
124 | |||
125 | /* export the GPIO to userspace */ | ||
126 | int gpiod_export(struct gpio_desc *desc, bool direction_may_change); | ||
127 | |||
128 | /* reverse gpio_export() */ | ||
129 | void gpiod_unexport(struct gpio_desc *desc); | ||
130 | |||
131 | /* create a sysfs link to an exported GPIO node */ | ||
132 | int gpiod_export_link(struct device *dev, const char *name, | ||
133 | struct gpio_desc *desc); | ||
134 | |||
135 | /* change the polarity of a GPIO node in sysfs */ | ||
136 | int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value); | ||
137 | |||
138 | After a kernel driver requests a GPIO, it may only be made available in | ||
139 | the sysfs interface by gpiod_export(). The driver can control whether the | ||
140 | signal direction may change. This helps drivers prevent userspace code | ||
141 | from accidentally clobbering important system state. | ||
142 | |||
143 | This explicit exporting can help with debugging (by making some kinds | ||
144 | of experiments easier), or can provide an always-there interface that's | ||
145 | suitable for documenting as part of a board support package. | ||
146 | |||
147 | After the GPIO has been exported, gpiod_export_link() allows creating | ||
148 | symlinks from elsewhere in sysfs to the GPIO sysfs node. Drivers can | ||
149 | use this to provide the interface under their own device in sysfs with | ||
150 | a descriptive name. | ||
151 | |||
152 | Drivers can use gpiod_sysfs_set_active_low() to hide GPIO line polarity | ||
153 | differences between boards from user space. Polarity change can be done both | ||
154 | before and after gpiod_export(), and previously enabled poll(2) support for | ||
155 | either rising or falling edge will be reconfigured to follow this setting. | ||
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 50680a59a2ff..b9e9bd854298 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt | |||
@@ -1529,6 +1529,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
1529 | 1529 | ||
1530 | * atapi_dmadir: Enable ATAPI DMADIR bridge support | 1530 | * atapi_dmadir: Enable ATAPI DMADIR bridge support |
1531 | 1531 | ||
1532 | * disable: Disable this device. | ||
1533 | |||
1532 | If there are multiple matching configurations changing | 1534 | If there are multiple matching configurations changing |
1533 | the same attribute, the last one is used. | 1535 | the same attribute, the last one is used. |
1534 | 1536 | ||
diff --git a/Documentation/mic/mpssd/mpssd.c b/Documentation/mic/mpssd/mpssd.c index 0c980ad40b17..4d17487d5ad9 100644 --- a/Documentation/mic/mpssd/mpssd.c +++ b/Documentation/mic/mpssd/mpssd.c | |||
@@ -313,7 +313,7 @@ static struct mic_device_desc *get_device_desc(struct mic_info *mic, int type) | |||
313 | int i; | 313 | int i; |
314 | void *dp = get_dp(mic, type); | 314 | void *dp = get_dp(mic, type); |
315 | 315 | ||
316 | for (i = mic_aligned_size(struct mic_bootparam); i < PAGE_SIZE; | 316 | for (i = sizeof(struct mic_bootparam); i < PAGE_SIZE; |
317 | i += mic_total_desc_size(d)) { | 317 | i += mic_total_desc_size(d)) { |
318 | d = dp + i; | 318 | d = dp + i; |
319 | 319 | ||
@@ -445,8 +445,8 @@ init_vr(struct mic_info *mic, int fd, int type, | |||
445 | __func__, mic->name, vr0->va, vr0->info, vr_size, | 445 | __func__, mic->name, vr0->va, vr0->info, vr_size, |
446 | vring_size(MIC_VRING_ENTRIES, MIC_VIRTIO_RING_ALIGN)); | 446 | vring_size(MIC_VRING_ENTRIES, MIC_VIRTIO_RING_ALIGN)); |
447 | mpsslog("magic 0x%x expected 0x%x\n", | 447 | mpsslog("magic 0x%x expected 0x%x\n", |
448 | vr0->info->magic, MIC_MAGIC + type); | 448 | le32toh(vr0->info->magic), MIC_MAGIC + type); |
449 | assert(vr0->info->magic == MIC_MAGIC + type); | 449 | assert(le32toh(vr0->info->magic) == MIC_MAGIC + type); |
450 | if (vr1) { | 450 | if (vr1) { |
451 | vr1->va = (struct mic_vring *) | 451 | vr1->va = (struct mic_vring *) |
452 | &va[MIC_DEVICE_PAGE_END + vr_size]; | 452 | &va[MIC_DEVICE_PAGE_END + vr_size]; |
@@ -458,8 +458,8 @@ init_vr(struct mic_info *mic, int fd, int type, | |||
458 | __func__, mic->name, vr1->va, vr1->info, vr_size, | 458 | __func__, mic->name, vr1->va, vr1->info, vr_size, |
459 | vring_size(MIC_VRING_ENTRIES, MIC_VIRTIO_RING_ALIGN)); | 459 | vring_size(MIC_VRING_ENTRIES, MIC_VIRTIO_RING_ALIGN)); |
460 | mpsslog("magic 0x%x expected 0x%x\n", | 460 | mpsslog("magic 0x%x expected 0x%x\n", |
461 | vr1->info->magic, MIC_MAGIC + type + 1); | 461 | le32toh(vr1->info->magic), MIC_MAGIC + type + 1); |
462 | assert(vr1->info->magic == MIC_MAGIC + type + 1); | 462 | assert(le32toh(vr1->info->magic) == MIC_MAGIC + type + 1); |
463 | } | 463 | } |
464 | done: | 464 | done: |
465 | return va; | 465 | return va; |
@@ -520,7 +520,7 @@ static void * | |||
520 | virtio_net(void *arg) | 520 | virtio_net(void *arg) |
521 | { | 521 | { |
522 | static __u8 vnet_hdr[2][sizeof(struct virtio_net_hdr)]; | 522 | static __u8 vnet_hdr[2][sizeof(struct virtio_net_hdr)]; |
523 | static __u8 vnet_buf[2][MAX_NET_PKT_SIZE] __aligned(64); | 523 | static __u8 vnet_buf[2][MAX_NET_PKT_SIZE] __attribute__ ((aligned(64))); |
524 | struct iovec vnet_iov[2][2] = { | 524 | struct iovec vnet_iov[2][2] = { |
525 | { { .iov_base = vnet_hdr[0], .iov_len = sizeof(vnet_hdr[0]) }, | 525 | { { .iov_base = vnet_hdr[0], .iov_len = sizeof(vnet_hdr[0]) }, |
526 | { .iov_base = vnet_buf[0], .iov_len = sizeof(vnet_buf[0]) } }, | 526 | { .iov_base = vnet_buf[0], .iov_len = sizeof(vnet_buf[0]) } }, |
@@ -1412,6 +1412,12 @@ mic_config(void *arg) | |||
1412 | } | 1412 | } |
1413 | 1413 | ||
1414 | do { | 1414 | do { |
1415 | ret = lseek(fd, 0, SEEK_SET); | ||
1416 | if (ret < 0) { | ||
1417 | mpsslog("%s: Failed to seek to file start '%s': %s\n", | ||
1418 | mic->name, pathname, strerror(errno)); | ||
1419 | goto close_error1; | ||
1420 | } | ||
1415 | ret = read(fd, value, sizeof(value)); | 1421 | ret = read(fd, value, sizeof(value)); |
1416 | if (ret < 0) { | 1422 | if (ret < 0) { |
1417 | mpsslog("%s: Failed to read sysfs entry '%s': %s\n", | 1423 | mpsslog("%s: Failed to read sysfs entry '%s': %s\n", |
diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt new file mode 100644 index 000000000000..2b40e04d3c49 --- /dev/null +++ b/Documentation/module-signing.txt | |||
@@ -0,0 +1,240 @@ | |||
1 | ============================== | ||
2 | KERNEL MODULE SIGNING FACILITY | ||
3 | ============================== | ||
4 | |||
5 | CONTENTS | ||
6 | |||
7 | - Overview. | ||
8 | - Configuring module signing. | ||
9 | - Generating signing keys. | ||
10 | - Public keys in the kernel. | ||
11 | - Manually signing modules. | ||
12 | - Signed modules and stripping. | ||
13 | - Loading signed modules. | ||
14 | - Non-valid signatures and unsigned modules. | ||
15 | - Administering/protecting the private key. | ||
16 | |||
17 | |||
18 | ======== | ||
19 | OVERVIEW | ||
20 | ======== | ||
21 | |||
22 | The kernel module signing facility cryptographically signs modules during | ||
23 | installation and then checks the signature upon loading the module. This | ||
24 | allows increased kernel security by disallowing the loading of unsigned modules | ||
25 | or modules signed with an invalid key. Module signing increases security by | ||
26 | making it harder to load a malicious module into the kernel. The module | ||
27 | signature checking is done by the kernel so that it is not necessary to have | ||
28 | trusted userspace bits. | ||
29 | |||
30 | This facility uses X.509 ITU-T standard certificates to encode the public keys | ||
31 | involved. The signatures are not themselves encoded in any industrial standard | ||
32 | type. The facility currently only supports the RSA public key encryption | ||
33 | standard (though it is pluggable and permits others to be used). The possible | ||
34 | hash algorithms that can be used are SHA-1, SHA-224, SHA-256, SHA-384, and | ||
35 | SHA-512 (the algorithm is selected by data in the signature). | ||
36 | |||
37 | |||
38 | ========================== | ||
39 | CONFIGURING MODULE SIGNING | ||
40 | ========================== | ||
41 | |||
42 | The module signing facility is enabled by going to the "Enable Loadable Module | ||
43 | Support" section of the kernel configuration and turning on | ||
44 | |||
45 | CONFIG_MODULE_SIG "Module signature verification" | ||
46 | |||
47 | This has a number of options available: | ||
48 | |||
49 | (1) "Require modules to be validly signed" (CONFIG_MODULE_SIG_FORCE) | ||
50 | |||
51 | This specifies how the kernel should deal with a module that has a | ||
52 | signature for which the key is not known or a module that is unsigned. | ||
53 | |||
54 | If this is off (ie. "permissive"), then modules for which the key is not | ||
55 | available and modules that are unsigned are permitted, but the kernel will | ||
56 | be marked as being tainted. | ||
57 | |||
58 | If this is on (ie. "restrictive"), only modules that have a valid | ||
59 | signature that can be verified by a public key in the kernel's possession | ||
60 | will be loaded. All other modules will generate an error. | ||
61 | |||
62 | Irrespective of the setting here, if the module has a signature block that | ||
63 | cannot be parsed, it will be rejected out of hand. | ||
64 | |||
65 | |||
66 | (2) "Automatically sign all modules" (CONFIG_MODULE_SIG_ALL) | ||
67 | |||
68 | If this is on then modules will be automatically signed during the | ||
69 | modules_install phase of a build. If this is off, then the modules must | ||
70 | be signed manually using: | ||
71 | |||
72 | scripts/sign-file | ||
73 | |||
74 | |||
75 | (3) "Which hash algorithm should modules be signed with?" | ||
76 | |||
77 | This presents a choice of which hash algorithm the installation phase will | ||
78 | sign the modules with: | ||
79 | |||
80 | CONFIG_SIG_SHA1 "Sign modules with SHA-1" | ||
81 | CONFIG_SIG_SHA224 "Sign modules with SHA-224" | ||
82 | CONFIG_SIG_SHA256 "Sign modules with SHA-256" | ||
83 | CONFIG_SIG_SHA384 "Sign modules with SHA-384" | ||
84 | CONFIG_SIG_SHA512 "Sign modules with SHA-512" | ||
85 | |||
86 | The algorithm selected here will also be built into the kernel (rather | ||
87 | than being a module) so that modules signed with that algorithm can have | ||
88 | their signatures checked without causing a dependency loop. | ||
89 | |||
90 | |||
91 | ======================= | ||
92 | GENERATING SIGNING KEYS | ||
93 | ======================= | ||
94 | |||
95 | Cryptographic keypairs are required to generate and check signatures. A | ||
96 | private key is used to generate a signature and the corresponding public key is | ||
97 | used to check it. The private key is only needed during the build, after which | ||
98 | it can be deleted or stored securely. The public key gets built into the | ||
99 | kernel so that it can be used to check the signatures as the modules are | ||
100 | loaded. | ||
101 | |||
102 | Under normal conditions, the kernel build will automatically generate a new | ||
103 | keypair using openssl if one does not exist in the files: | ||
104 | |||
105 | signing_key.priv | ||
106 | signing_key.x509 | ||
107 | |||
108 | during the building of vmlinux (the public part of the key needs to be built | ||
109 | into vmlinux) using parameters in the: | ||
110 | |||
111 | x509.genkey | ||
112 | |||
113 | file (which is also generated if it does not already exist). | ||
114 | |||
115 | It is strongly recommended that you provide your own x509.genkey file. | ||
116 | |||
117 | Most notably, in the x509.genkey file, the req_distinguished_name section | ||
118 | should be altered from the default: | ||
119 | |||
120 | [ req_distinguished_name ] | ||
121 | O = Magrathea | ||
122 | CN = Glacier signing key | ||
123 | emailAddress = slartibartfast@magrathea.h2g2 | ||
124 | |||
125 | The generated RSA key size can also be set with: | ||
126 | |||
127 | [ req ] | ||
128 | default_bits = 4096 | ||
129 | |||
130 | |||
131 | It is also possible to manually generate the key private/public files using the | ||
132 | x509.genkey key generation configuration file in the root node of the Linux | ||
133 | kernel sources tree and the openssl command. The following is an example to | ||
134 | generate the public/private key files: | ||
135 | |||
136 | openssl req -new -nodes -utf8 -sha256 -days 36500 -batch -x509 \ | ||
137 | -config x509.genkey -outform DER -out signing_key.x509 \ | ||
138 | -keyout signing_key.priv | ||
139 | |||
140 | |||
141 | ========================= | ||
142 | PUBLIC KEYS IN THE KERNEL | ||
143 | ========================= | ||
144 | |||
145 | The kernel contains a ring of public keys that can be viewed by root. They're | ||
146 | in a keyring called ".system_keyring" that can be seen by: | ||
147 | |||
148 | [root@deneb ~]# cat /proc/keys | ||
149 | ... | ||
150 | 223c7853 I------ 1 perm 1f030000 0 0 keyring .system_keyring: 1 | ||
151 | 302d2d52 I------ 1 perm 1f010000 0 0 asymmetri Fedora kernel signing key: d69a84e6bce3d216b979e9505b3e3ef9a7118079: X509.RSA a7118079 [] | ||
152 | ... | ||
153 | |||
154 | Beyond the public key generated specifically for module signing, any file | ||
155 | placed in the kernel source root directory or the kernel build root directory | ||
156 | whose name is suffixed with ".x509" will be assumed to be an X.509 public key | ||
157 | and will be added to the keyring. | ||
158 | |||
159 | Further, the architecture code may take public keys from a hardware store and | ||
160 | add those in also (e.g. from the UEFI key database). | ||
161 | |||
162 | Finally, it is possible to add additional public keys by doing: | ||
163 | |||
164 | keyctl padd asymmetric "" [.system_keyring-ID] <[key-file] | ||
165 | |||
166 | e.g.: | ||
167 | |||
168 | keyctl padd asymmetric "" 0x223c7853 <my_public_key.x509 | ||
169 | |||
170 | Note, however, that the kernel will only permit keys to be added to | ||
171 | .system_keyring _if_ the new key's X.509 wrapper is validly signed by a key | ||
172 | that is already resident in the .system_keyring at the time the key was added. | ||
173 | |||
174 | |||
175 | ========================= | ||
176 | MANUALLY SIGNING MODULES | ||
177 | ========================= | ||
178 | |||
179 | To manually sign a module, use the scripts/sign-file tool available in | ||
180 | the Linux kernel source tree. The script requires 4 arguments: | ||
181 | |||
182 | 1. The hash algorithm (e.g., sha256) | ||
183 | 2. The private key filename | ||
184 | 3. The public key filename | ||
185 | 4. The kernel module to be signed | ||
186 | |||
187 | The following is an example to sign a kernel module: | ||
188 | |||
189 | scripts/sign-file sha512 kernel-signkey.priv \ | ||
190 | kernel-signkey.x509 module.ko | ||
191 | |||
192 | The hash algorithm used does not have to match the one configured, but if it | ||
193 | doesn't, you should make sure that hash algorithm is either built into the | ||
194 | kernel or can be loaded without requiring itself. | ||
195 | |||
196 | |||
197 | ============================ | ||
198 | SIGNED MODULES AND STRIPPING | ||
199 | ============================ | ||
200 | |||
201 | A signed module has a digital signature simply appended at the end. The string | ||
202 | "~Module signature appended~." at the end of the module's file confirms that a | ||
203 | signature is present but it does not confirm that the signature is valid! | ||
204 | |||
205 | Signed modules are BRITTLE as the signature is outside of the defined ELF | ||
206 | container. Thus they MAY NOT be stripped once the signature is computed and | ||
207 | attached. Note the entire module is the signed payload, including any and all | ||
208 | debug information present at the time of signing. | ||
209 | |||
210 | |||
211 | ====================== | ||
212 | LOADING SIGNED MODULES | ||
213 | ====================== | ||
214 | |||
215 | Modules are loaded with insmod, modprobe, init_module() or finit_module(), | ||
216 | exactly as for unsigned modules as no processing is done in userspace. The | ||
217 | signature checking is all done within the kernel. | ||
218 | |||
219 | |||
220 | ========================================= | ||
221 | NON-VALID SIGNATURES AND UNSIGNED MODULES | ||
222 | ========================================= | ||
223 | |||
224 | If CONFIG_MODULE_SIG_FORCE is enabled or enforcemodulesig=1 is supplied on | ||
225 | the kernel command line, the kernel will only load validly signed modules | ||
226 | for which it has a public key. Otherwise, it will also load modules that are | ||
227 | unsigned. Any module for which the kernel has a key, but which proves to have | ||
228 | a signature mismatch will not be permitted to load. | ||
229 | |||
230 | Any module that has an unparseable signature will be rejected. | ||
231 | |||
232 | |||
233 | ========================================= | ||
234 | ADMINISTERING/PROTECTING THE PRIVATE KEY | ||
235 | ========================================= | ||
236 | |||
237 | Since the private key is used to sign modules, viruses and malware could use | ||
238 | the private key to sign modules and compromise the operating system. The | ||
239 | private key must be either destroyed or moved to a secure location and not kept | ||
240 | in the root node of the kernel source tree. | ||
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 3c12d9a7ed00..8a984e994e61 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt | |||
@@ -16,8 +16,12 @@ ip_default_ttl - INTEGER | |||
16 | Default: 64 (as recommended by RFC1700) | 16 | Default: 64 (as recommended by RFC1700) |
17 | 17 | ||
18 | ip_no_pmtu_disc - BOOLEAN | 18 | ip_no_pmtu_disc - BOOLEAN |
19 | Disable Path MTU Discovery. | 19 | Disable Path MTU Discovery. If enabled and a |
20 | default FALSE | 20 | fragmentation-required ICMP is received, the PMTU to this |
21 | destination will be set to min_pmtu (see below). You will need | ||
22 | to raise min_pmtu to the smallest interface MTU on your system | ||
23 | manually if you want to avoid locally generated fragments. | ||
24 | Default: FALSE | ||
21 | 25 | ||
22 | min_pmtu - INTEGER | 26 | min_pmtu - INTEGER |
23 | default 552 - minimum discovered Path MTU | 27 | default 552 - minimum discovered Path MTU |
diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt index c01223628a87..8e48e3b14227 100644 --- a/Documentation/networking/packet_mmap.txt +++ b/Documentation/networking/packet_mmap.txt | |||
@@ -123,6 +123,16 @@ Transmission process is similar to capture as shown below. | |||
123 | [shutdown] close() --------> destruction of the transmission socket and | 123 | [shutdown] close() --------> destruction of the transmission socket and |
124 | deallocation of all associated resources. | 124 | deallocation of all associated resources. |
125 | 125 | ||
126 | Socket creation and destruction is also straight forward, and is done | ||
127 | the same way as in capturing described in the previous paragraph: | ||
128 | |||
129 | int fd = socket(PF_PACKET, mode, 0); | ||
130 | |||
131 | The protocol can optionally be 0 in case we only want to transmit | ||
132 | via this socket, which avoids an expensive call to packet_rcv(). | ||
133 | In this case, you also need to bind(2) the TX_RING with sll_protocol = 0 | ||
134 | set. Otherwise, htons(ETH_P_ALL) or any other protocol, for example. | ||
135 | |||
126 | Binding the socket to your network interface is mandatory (with zero copy) to | 136 | Binding the socket to your network interface is mandatory (with zero copy) to |
127 | know the header size of frames used in the circular buffer. | 137 | know the header size of frames used in the circular buffer. |
128 | 138 | ||