aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-28 14:02:32 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-28 14:02:32 -0400
commit61abfd2df8aa43a137ae58446dd0638a2385586e (patch)
tree70e54fd22dbe8d7064f8cac47b43c7d5406048ab /Documentation
parent4075ea8c54a7506844a69f674990241e7766357b (diff)
parenta1dd8c617217322614f0465ae347895c4b58e1ab (diff)
Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds
* 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds: leds: Futher document blink_set leds: Add options to have GPIO LEDs start on or keep their state leds: LED driver for National Semiconductor LP3944 Funlight Chip leds: pca9532 - Indent using tabs, not spaces. leds: Remove an orphan Kconfig entry leds: Further document parameters for blink_set() leds: alix-leds2 fixed for Award BIOS leds: leds-gpio - fix a section mismatch leds: add the sysfs interface into the leds-bd2802 driver for changing wave pattern and led current. leds: change the license information leds: fix led-bd2802 errors while resuming
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/leds-lp3944.txt50
-rw-r--r--Documentation/powerpc/dts-bindings/gpio/led.txt17
2 files changed, 66 insertions, 1 deletions
diff --git a/Documentation/leds-lp3944.txt b/Documentation/leds-lp3944.txt
new file mode 100644
index 000000000000..c6eda18b15ef
--- /dev/null
+++ b/Documentation/leds-lp3944.txt
@@ -0,0 +1,50 @@
1Kernel driver lp3944
2====================
3
4 * National Semiconductor LP3944 Fun-light Chip
5 Prefix: 'lp3944'
6 Addresses scanned: None (see the Notes section below)
7 Datasheet: Publicly available at the National Semiconductor website
8 http://www.national.com/pf/LP/LP3944.html
9
10Authors:
11 Antonio Ospite <ospite@studenti.unina.it>
12
13
14Description
15-----------
16The LP3944 is a helper chip that can drive up to 8 leds, with two programmable
17DIM modes; it could even be used as a gpio expander but this driver assumes it
18is used as a led controller.
19
20The DIM modes are used to set _blink_ patterns for leds, the pattern is
21specified supplying two parameters:
22 - period: from 0s to 1.6s
23 - duty cycle: percentage of the period the led is on, from 0 to 100
24
25Setting a led in DIM0 or DIM1 mode makes it blink according to the pattern.
26See the datasheet for details.
27
28LP3944 can be found on Motorola A910 smartphone, where it drives the rgb
29leds, the camera flash light and the lcds power.
30
31
32Notes
33-----
34The chip is used mainly in embedded contexts, so this driver expects it is
35registered using the i2c_board_info mechanism.
36
37To register the chip at address 0x60 on adapter 0, set the platform data
38according to include/linux/leds-lp3944.h, set the i2c board info:
39
40 static struct i2c_board_info __initdata a910_i2c_board_info[] = {
41 {
42 I2C_BOARD_INFO("lp3944", 0x60),
43 .platform_data = &a910_lp3944_leds,
44 },
45 };
46
47and register it in the platform init function
48
49 i2c_register_board_info(0, a910_i2c_board_info,
50 ARRAY_SIZE(a910_i2c_board_info));
diff --git a/Documentation/powerpc/dts-bindings/gpio/led.txt b/Documentation/powerpc/dts-bindings/gpio/led.txt
index 4fe14deedc0a..064db928c3c1 100644
--- a/Documentation/powerpc/dts-bindings/gpio/led.txt
+++ b/Documentation/powerpc/dts-bindings/gpio/led.txt
@@ -16,10 +16,17 @@ LED sub-node properties:
16 string defining the trigger assigned to the LED. Current triggers are: 16 string defining the trigger assigned to the LED. Current triggers are:
17 "backlight" - LED will act as a back-light, controlled by the framebuffer 17 "backlight" - LED will act as a back-light, controlled by the framebuffer
18 system 18 system
19 "default-on" - LED will turn on 19 "default-on" - LED will turn on, but see "default-state" below
20 "heartbeat" - LED "double" flashes at a load average based rate 20 "heartbeat" - LED "double" flashes at a load average based rate
21 "ide-disk" - LED indicates disk activity 21 "ide-disk" - LED indicates disk activity
22 "timer" - LED flashes at a fixed, configurable rate 22 "timer" - LED flashes at a fixed, configurable rate
23- default-state: (optional) The initial state of the LED. Valid
24 values are "on", "off", and "keep". If the LED is already on or off
25 and the default-state property is set the to same value, then no
26 glitch should be produced where the LED momentarily turns off (or
27 on). The "keep" setting will keep the LED at whatever its current
28 state is, without producing a glitch. The default is off if this
29 property is not present.
23 30
24Examples: 31Examples:
25 32
@@ -30,14 +37,22 @@ leds {
30 gpios = <&mcu_pio 0 1>; /* Active low */ 37 gpios = <&mcu_pio 0 1>; /* Active low */
31 linux,default-trigger = "ide-disk"; 38 linux,default-trigger = "ide-disk";
32 }; 39 };
40
41 fault {
42 gpios = <&mcu_pio 1 0>;
43 /* Keep LED on if BIOS detected hardware fault */
44 default-state = "keep";
45 };
33}; 46};
34 47
35run-control { 48run-control {
36 compatible = "gpio-leds"; 49 compatible = "gpio-leds";
37 red { 50 red {
38 gpios = <&mpc8572 6 0>; 51 gpios = <&mpc8572 6 0>;
52 default-state = "off";
39 }; 53 };
40 green { 54 green {
41 gpios = <&mpc8572 7 0>; 55 gpios = <&mpc8572 7 0>;
56 default-state = "on";
42 }; 57 };
43} 58}