diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-21 18:42:20 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-21 18:42:53 -0400 |
commit | 93ded9b8fd42abe2c3607097963d8de6ad9117eb (patch) | |
tree | 407a3adcf885ffd75a4d3299eaefd9b171b739be /Documentation | |
parent | 6d52dcbe56ca8464bcad56d98a64bcd781596663 (diff) | |
parent | f756cbd458ab71c996a069cb3928fb1e2d7cd9cc (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (100 commits)
usb-storage: revert DMA-alignment change for Wireless USB
USB: use reset_resume when normal resume fails
usb_gadget: composite cdc gadget fault handling
usb gadget: minor USBCV fix for composite framework
USB: Fix bug with byte order in isp116x-hcd.c fio write/read
USB: fix double kfree in ipaq in error case
USB: fix build error in cdc-acm for CONFIG_PM=n
USB: remove board-specific UP2OCR configuration from pxa27x-udc
USB: EHCI: Reconciling USB register differences on MPC85xx vs MPC83xx
USB: Fix pointer/int cast in USB devio code
usb gadget: g_cdc dependso on NET
USB: Au1xxx-usb: suspend/resume support.
USB: Au1xxx-usb: clean up ohci/ehci bus glue sources.
usbfs: don't store bad pointers in registration
usbfs: fix race between open and unregister
usbfs: simplify the lookup-by-minor routines
usbfs: send disconnect signals when device is unregistered
USB: Force unbinding of drivers lacking reset_resume or other methods
USB: ohci-pnx4008: I2C cleanups and fixes
USB: debug port converter does not accept more than 8 byte packets
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/DocBook/gadget.tmpl | 38 | ||||
-rw-r--r-- | Documentation/usb/gadget_serial.txt | 35 | ||||
-rw-r--r-- | Documentation/usb/persist.txt | 7 | ||||
-rw-r--r-- | Documentation/usb/uhci.txt | 165 |
4 files changed, 69 insertions, 176 deletions
diff --git a/Documentation/DocBook/gadget.tmpl b/Documentation/DocBook/gadget.tmpl index 5a8ffa761e09..ea3bc9565e6a 100644 --- a/Documentation/DocBook/gadget.tmpl +++ b/Documentation/DocBook/gadget.tmpl | |||
@@ -524,6 +524,44 @@ These utilities include endpoint autoconfiguration. | |||
524 | <!-- !Edrivers/usb/gadget/epautoconf.c --> | 524 | <!-- !Edrivers/usb/gadget/epautoconf.c --> |
525 | </sect1> | 525 | </sect1> |
526 | 526 | ||
527 | <sect1 id="composite"><title>Composite Device Framework</title> | ||
528 | |||
529 | <para>The core API is sufficient for writing drivers for composite | ||
530 | USB devices (with more than one function in a given configuration), | ||
531 | and also multi-configuration devices (also more than one function, | ||
532 | but not necessarily sharing a given configuration). | ||
533 | There is however an optional framework which makes it easier to | ||
534 | reuse and combine functions. | ||
535 | </para> | ||
536 | |||
537 | <para>Devices using this framework provide a <emphasis>struct | ||
538 | usb_composite_driver</emphasis>, which in turn provides one or | ||
539 | more <emphasis>struct usb_configuration</emphasis> instances. | ||
540 | Each such configuration includes at least one | ||
541 | <emphasis>struct usb_function</emphasis>, which packages a user | ||
542 | visible role such as "network link" or "mass storage device". | ||
543 | Management functions may also exist, such as "Device Firmware | ||
544 | Upgrade". | ||
545 | </para> | ||
546 | |||
547 | !Iinclude/linux/usb/composite.h | ||
548 | !Edrivers/usb/gadget/composite.c | ||
549 | |||
550 | </sect1> | ||
551 | |||
552 | <sect1 id="functions"><title>Composite Device Functions</title> | ||
553 | |||
554 | <para>At this writing, a few of the current gadget drivers have | ||
555 | been converted to this framework. | ||
556 | Near-term plans include converting all of them, except for "gadgetfs". | ||
557 | </para> | ||
558 | |||
559 | !Edrivers/usb/gadget/f_acm.c | ||
560 | !Edrivers/usb/gadget/f_serial.c | ||
561 | |||
562 | </sect1> | ||
563 | |||
564 | |||
527 | </chapter> | 565 | </chapter> |
528 | 566 | ||
529 | <chapter id="controllers"><title>Peripheral Controller Drivers</title> | 567 | <chapter id="controllers"><title>Peripheral Controller Drivers</title> |
diff --git a/Documentation/usb/gadget_serial.txt b/Documentation/usb/gadget_serial.txt index 815f5c2301ff..9b22bd14c348 100644 --- a/Documentation/usb/gadget_serial.txt +++ b/Documentation/usb/gadget_serial.txt | |||
@@ -1,6 +1,7 @@ | |||
1 | 1 | ||
2 | Linux Gadget Serial Driver v2.0 | 2 | Linux Gadget Serial Driver v2.0 |
3 | 11/20/2004 | 3 | 11/20/2004 |
4 | (updated 8-May-2008 for v2.3) | ||
4 | 5 | ||
5 | 6 | ||
6 | License and Disclaimer | 7 | License and Disclaimer |
@@ -31,7 +32,7 @@ Prerequisites | |||
31 | ------------- | 32 | ------------- |
32 | Versions of the gadget serial driver are available for the | 33 | Versions of the gadget serial driver are available for the |
33 | 2.4 Linux kernels, but this document assumes you are using | 34 | 2.4 Linux kernels, but this document assumes you are using |
34 | version 2.0 or later of the gadget serial driver in a 2.6 | 35 | version 2.3 or later of the gadget serial driver in a 2.6 |
35 | Linux kernel. | 36 | Linux kernel. |
36 | 37 | ||
37 | This document assumes that you are familiar with Linux and | 38 | This document assumes that you are familiar with Linux and |
@@ -40,6 +41,12 @@ standard utilities, use minicom and HyperTerminal, and work with | |||
40 | USB and serial devices. It also assumes you configure the Linux | 41 | USB and serial devices. It also assumes you configure the Linux |
41 | gadget and usb drivers as modules. | 42 | gadget and usb drivers as modules. |
42 | 43 | ||
44 | With version 2.3 of the driver, major and minor device nodes are | ||
45 | no longer statically defined. Your Linux based system should mount | ||
46 | sysfs in /sys, and use "mdev" (in Busybox) or "udev" to make the | ||
47 | /dev nodes matching the sysfs /sys/class/tty files. | ||
48 | |||
49 | |||
43 | 50 | ||
44 | Overview | 51 | Overview |
45 | -------- | 52 | -------- |
@@ -104,15 +111,8 @@ driver. All this are listed under "USB Gadget Support" when | |||
104 | configuring the kernel. Then rebuild and install the kernel or | 111 | configuring the kernel. Then rebuild and install the kernel or |
105 | modules. | 112 | modules. |
106 | 113 | ||
107 | The gadget serial driver uses major number 127, for now. So you | ||
108 | will need to create a device node for it, like this: | ||
109 | |||
110 | mknod /dev/ttygserial c 127 0 | ||
111 | |||
112 | You only need to do this once. | ||
113 | |||
114 | Then you must load the gadget serial driver. To load it as an | 114 | Then you must load the gadget serial driver. To load it as an |
115 | ACM device, do this: | 115 | ACM device (recommended for interoperability), do this: |
116 | 116 | ||
117 | modprobe g_serial use_acm=1 | 117 | modprobe g_serial use_acm=1 |
118 | 118 | ||
@@ -125,6 +125,23 @@ controller driver. This must be done each time you reboot the gadget | |||
125 | side Linux system. You can add this to the start up scripts, if | 125 | side Linux system. You can add this to the start up scripts, if |
126 | desired. | 126 | desired. |
127 | 127 | ||
128 | Your system should use mdev (from busybox) or udev to make the | ||
129 | device nodes. After this gadget driver has been set up you should | ||
130 | then see a /dev/ttyGS0 node: | ||
131 | |||
132 | # ls -l /dev/ttyGS0 | cat | ||
133 | crw-rw---- 1 root root 253, 0 May 8 14:10 /dev/ttyGS0 | ||
134 | # | ||
135 | |||
136 | Note that the major number (253, above) is system-specific. If | ||
137 | you need to create /dev nodes by hand, the right numbers to use | ||
138 | will be in the /sys/class/tty/ttyGS0/dev file. | ||
139 | |||
140 | When you link this gadget driver early, perhaps even statically, | ||
141 | you may want to set up an /etc/inittab entry to run "getty" on it. | ||
142 | The /dev/ttyGS0 line should work like most any other serial port. | ||
143 | |||
144 | |||
128 | If gadget serial is loaded as an ACM device you will want to use | 145 | If gadget serial is loaded as an ACM device you will want to use |
129 | either the Windows or Linux ACM driver on the host side. If gadget | 146 | either the Windows or Linux ACM driver on the host side. If gadget |
130 | serial is loaded as a bulk in/out device, you will want to use the | 147 | serial is loaded as a bulk in/out device, you will want to use the |
diff --git a/Documentation/usb/persist.txt b/Documentation/usb/persist.txt index d56cb1a11550..074b159b77c2 100644 --- a/Documentation/usb/persist.txt +++ b/Documentation/usb/persist.txt | |||
@@ -81,8 +81,11 @@ re-enumeration shows that the device now attached to that port has the | |||
81 | same descriptors as before, including the Vendor and Product IDs, then | 81 | same descriptors as before, including the Vendor and Product IDs, then |
82 | the kernel continues to use the same device structure. In effect, the | 82 | the kernel continues to use the same device structure. In effect, the |
83 | kernel treats the device as though it had merely been reset instead of | 83 | kernel treats the device as though it had merely been reset instead of |
84 | unplugged. The same thing happens if the host controller is in the | 84 | unplugged. |
85 | expected state but a USB device was unplugged and then replugged. | 85 | |
86 | The same thing happens if the host controller is in the expected state | ||
87 | but a USB device was unplugged and then replugged, or if a USB device | ||
88 | fails to carry out a normal resume. | ||
86 | 89 | ||
87 | If no device is now attached to the port, or if the descriptors are | 90 | If no device is now attached to the port, or if the descriptors are |
88 | different from what the kernel remembers, then the treatment is what | 91 | different from what the kernel remembers, then the treatment is what |
diff --git a/Documentation/usb/uhci.txt b/Documentation/usb/uhci.txt deleted file mode 100644 index 2f25952c86c6..000000000000 --- a/Documentation/usb/uhci.txt +++ /dev/null | |||
@@ -1,165 +0,0 @@ | |||
1 | Specification and Internals for the New UHCI Driver (Whitepaper...) | ||
2 | |||
3 | brought to you by | ||
4 | |||
5 | Georg Acher, acher@in.tum.de (executive slave) (base guitar) | ||
6 | Deti Fliegl, deti@fliegl.de (executive slave) (lead voice) | ||
7 | Thomas Sailer, sailer@ife.ee.ethz.ch (chief consultant) (cheer leader) | ||
8 | |||
9 | $Id: README.uhci,v 1.1 1999/12/14 14:03:02 fliegl Exp $ | ||
10 | |||
11 | This document and the new uhci sources can be found on | ||
12 | http://hotswap.in.tum.de/usb | ||
13 | |||
14 | 1. General issues | ||
15 | |||
16 | 1.1 Why a new UHCI driver, we already have one?!? | ||
17 | |||
18 | Correct, but its internal structure got more and more mixed up by the (still | ||
19 | ongoing) efforts to get isochronous transfers (ISO) to work. | ||
20 | Since there is an increasing need for reliable ISO-transfers (especially | ||
21 | for USB-audio needed by TS and for a DAB-USB-Receiver build by GA and DF), | ||
22 | this state was a bit unsatisfying in our opinion, so we've decided (based | ||
23 | on knowledge and experiences with the old UHCI driver) to start | ||
24 | from scratch with a new approach, much simpler but at the same time more | ||
25 | powerful. | ||
26 | It is inspired by the way Win98/Win2000 handles USB requests via URBs, | ||
27 | but it's definitely 100% free of MS-code and doesn't crash while | ||
28 | unplugging an used ISO-device like Win98 ;-) | ||
29 | Some code for HW setup and root hub management was taken from the | ||
30 | original UHCI driver, but heavily modified to fit into the new code. | ||
31 | The invention of the basic concept, and major coding were completed in two | ||
32 | days (and nights) on the 16th and 17th of October 1999, now known as the | ||
33 | great USB-October-Revolution started by GA, DF, and TS ;-) | ||
34 | |||
35 | Since the concept is in no way UHCI dependent, we hope that it will also be | ||
36 | transferred to the OHCI-driver, so both drivers share a common API. | ||
37 | |||
38 | 1.2. Advantages and disadvantages | ||
39 | |||
40 | + All USB transfer types work now! | ||
41 | + Asynchronous operation | ||
42 | + Simple, but powerful interface (only two calls for start and cancel) | ||
43 | + Easy migration to the new API, simplified by a compatibility API | ||
44 | + Simple usage of ISO transfers | ||
45 | + Automatic linking of requests | ||
46 | + ISO transfers allow variable length for each frame and striping | ||
47 | + No CPU dependent and non-portable atomic memory access, no asm()-inlines | ||
48 | + Tested on x86 and Alpha | ||
49 | |||
50 | - Rewriting for ISO transfers needed | ||
51 | |||
52 | 1.3. Is there some compatibility to the old API? | ||
53 | |||
54 | Yes, but only for control, bulk and interrupt transfers. We've implemented | ||
55 | some wrapper calls for these transfer types. The usbcore works fine with | ||
56 | these wrappers. For ISO there's no compatibility, because the old ISO-API | ||
57 | and its semantics were unnecessary complicated in our opinion. | ||
58 | |||
59 | 1.4. What's really working? | ||
60 | |||
61 | As said above, CTRL and BULK already work fine even with the wrappers, | ||
62 | so legacy code wouldn't notice the change. | ||
63 | Regarding to Thomas, ISO transfers now run stable with USB audio. | ||
64 | INT transfers (e.g. mouse driver) work fine, too. | ||
65 | |||
66 | 1.5. Are there any bugs? | ||
67 | |||
68 | No ;-) | ||
69 | Hm... | ||
70 | Well, of course this implementation needs extensive testing on all available | ||
71 | hardware, but we believe that any fixes shouldn't harm the overall concept. | ||
72 | |||
73 | 1.6. What should be done next? | ||
74 | |||
75 | A large part of the request handling seems to be identical for UHCI and | ||
76 | OHCI, so it would be a good idea to extract the common parts and have only | ||
77 | the HW specific stuff in uhci.c. Furthermore, all other USB device drivers | ||
78 | should need URBification, if they use isochronous or interrupt transfers. | ||
79 | One thing missing in the current implementation (and the old UHCI driver) | ||
80 | is fair queueing for BULK transfers. Since this would need (in principle) | ||
81 | the alteration of already constructed TD chains (to switch from depth to | ||
82 | breadth execution), another way has to be found. Maybe some simple | ||
83 | heuristics work with the same effect. | ||
84 | |||
85 | --------------------------------------------------------------------------- | ||
86 | |||
87 | 2. Internal structure and mechanisms | ||
88 | |||
89 | To get quickly familiar with the internal structures, here's a short | ||
90 | description how the new UHCI driver works. However, the ultimate source of | ||
91 | truth is only uhci.c! | ||
92 | |||
93 | 2.1. Descriptor structure (QHs and TDs) | ||
94 | |||
95 | During initialization, the following skeleton is allocated in init_skel: | ||
96 | |||
97 | framespecific | common chain | ||
98 | |||
99 | framelist[] | ||
100 | [ 0 ]-----> TD --> TD -------\ | ||
101 | [ 1 ]-----> TD --> TD --------> TD ----> QH -------> QH -------> QH ---> NULL | ||
102 | ... TD --> TD -------/ | ||
103 | [1023]-----> TD --> TD ------/ | ||
104 | |||
105 | ^^ ^^ ^^ ^^ ^^ ^^ | ||
106 | 1024 TDs for 7 TDs for 1 TD for Start of Start of End Chain | ||
107 | ISO INT (2-128ms) 1ms-INT CTRL Chain BULK Chain | ||
108 | |||
109 | For each CTRL or BULK transfer a new QH is allocated and the containing data | ||
110 | transfers are appended as (vertical) TDs. After building the whole QH with its | ||
111 | dangling TDs, the QH is inserted before the BULK Chain QH (for CTRL) or | ||
112 | before the End Chain QH (for BULK). Since only the QH->next pointers are | ||
113 | affected, no atomic memory operation is required. The three QHs in the | ||
114 | common chain are never equipped with TDs! | ||
115 | |||
116 | For ISO or INT, the TD for each frame is simply inserted into the appropriate | ||
117 | ISO/INT-TD-chain for the desired frame. The 7 skeleton INT-TDs are scattered | ||
118 | among the 1024 frames similar to the old UHCI driver. | ||
119 | |||
120 | For CTRL/BULK/ISO, the last TD in the transfer has the IOC-bit set. For INT, | ||
121 | every TD (there is only one...) has the IOC-bit set. | ||
122 | |||
123 | Besides the data for the UHCI controller (2 or 4 32bit words), the descriptors | ||
124 | are double-linked through the .vertical and .horizontal elements in the | ||
125 | SW data of the descriptor (using the double-linked list structures and | ||
126 | operations), but SW-linking occurs only in closed domains, i.e. for each of | ||
127 | the 1024 ISO-chains and the 8 INT-chains there is a closed cycle. This | ||
128 | simplifies all insertions and unlinking operations and avoids costly | ||
129 | bus_to_virt()-calls. | ||
130 | |||
131 | 2.2. URB structure and linking to QH/TDs | ||
132 | |||
133 | During assembly of the QH and TDs of the requested action, these descriptors | ||
134 | are stored in urb->urb_list, so the allocated QH/TD descriptors are bound to | ||
135 | this URB. | ||
136 | If the assembly was successful and the descriptors were added to the HW chain, | ||
137 | the corresponding URB is inserted into a global URB list for this controller. | ||
138 | This list stores all pending URBs. | ||
139 | |||
140 | 2.3. Interrupt processing | ||
141 | |||
142 | Since UHCI provides no means to directly detect completed transactions, the | ||
143 | following is done in each UHCI interrupt (uhci_interrupt()): | ||
144 | |||
145 | For each URB in the pending queue (process_urb()), the ACTIVE-flag of the | ||
146 | associated TDs are processed (depending on the transfer type | ||
147 | process_{transfer|interrupt|iso}()). If the TDs are not active anymore, | ||
148 | they indicate the completion of the transaction and the status is calculated. | ||
149 | Inactive QH/TDs are removed from the HW chain (since the host controller | ||
150 | already removed the TDs from the QH, no atomic access is needed) and | ||
151 | eventually the URB is marked as completed (OK or errors) and removed from the | ||
152 | pending queue. Then the next linked URB is submitted. After (or immediately | ||
153 | before) that, the completion handler is called. | ||
154 | |||
155 | 2.4. Unlinking URBs | ||
156 | |||
157 | First, all QH/TDs stored in the URB are unlinked from the HW chain. | ||
158 | To ensure that the host controller really left a vertical TD chain, we | ||
159 | wait for one frame. After that, the TDs are physically destroyed. | ||
160 | |||
161 | 2.5. URB linking and the consequences | ||
162 | |||
163 | Since URBs can be linked and the corresponding submit_urb is called in | ||
164 | the UHCI-interrupt, all work associated with URB/QH/TD assembly has to be | ||
165 | interrupt save. This forces kmalloc to use GFP_ATOMIC in the interrupt. | ||