Commit | Line | Data |
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5991e154 SO |
1 | Kernel driver for lp5523 |
2 | ======================== | |
3 | ||
4 | * National Semiconductor LP5523 led driver chip | |
5 | * Datasheet: http://www.national.com/pf/LP/LP5523.html | |
6 | ||
7 | Authors: Mathias Nyman, Yuri Zaporozhets, Samu Onkalo | |
8 | Contact: Samu Onkalo (samu.p.onkalo-at-nokia.com) | |
9 | ||
10 | Description | |
11 | ----------- | |
12 | LP5523 can drive up to 9 channels. Leds can be controlled directly via | |
13 | the led class control interface. Channels have generic names: | |
14 | lp5523:channelx where x is 0...8 | |
15 | ||
16 | The chip provides 3 engines. Each engine can control channels without | |
17 | interaction from the main CPU. Details of the micro engine code can be found | |
18 | from the public data sheet. Leds can be muxed to different channels. | |
19 | ||
20 | Control interface for the engines: | |
21 | x is 1 .. 3 | |
22 | enginex_mode : disabled, load, run | |
23 | enginex_load : microcode load (visible only in load mode) | |
24 | enginex_leds : led mux control (visible only in load mode) | |
25 | ||
26 | cd /sys/class/leds/lp5523:channel2/device | |
27 | echo "load" > engine3_mode | |
28 | echo "9d80400004ff05ff437f0000" > engine3_load | |
29 | echo "111111111" > engine3_leds | |
30 | echo "run" > engine3_mode | |
31 | ||
32 | sysfs contains a selftest entry. It measures each channel | |
33 | voltage level and checks if it looks reasonable. If the level is too high, | |
34 | the led is missing; if the level is too low, there is a short circuit. | |
35 | ||
36 | Selftest uses always the current from the platform data. | |
37 | ||
38 | Each channel contains led current settings. | |
39 | /sys/class/leds/lp5523:channel2/led_current - RW | |
40 | /sys/class/leds/lp5523:channel2/max_current - RO | |
41 | Format: 10x mA i.e 10 means 1.0 mA | |
42 | ||
43 | Example platform data: | |
44 | ||
45 | Note - chan_nr can have values between 0 and 8. | |
46 | ||
47 | static struct lp5523_led_config lp5523_led_config[] = { | |
48 | { | |
49 | .chan_nr = 0, | |
50 | .led_current = 50, | |
51 | .max_current = 130, | |
52 | }, | |
53 | ... | |
54 | }, { | |
55 | .chan_nr = 8, | |
56 | .led_current = 50, | |
57 | .max_current = 130, | |
58 | } | |
59 | }; | |
60 | ||
61 | static int lp5523_setup(void) | |
62 | { | |
63 | /* Setup HW resources */ | |
64 | } | |
65 | ||
66 | static void lp5523_release(void) | |
67 | { | |
68 | /* Release HW resources */ | |
69 | } | |
70 | ||
71 | static void lp5523_enable(bool state) | |
72 | { | |
73 | /* Control chip enable signal */ | |
74 | } | |
75 | ||
76 | static struct lp5523_platform_data lp5523_platform_data = { | |
77 | .led_config = lp5523_led_config, | |
78 | .num_channels = ARRAY_SIZE(lp5523_led_config), | |
79 | .clock_mode = LP5523_CLOCK_EXT, | |
80 | .setup_resources = lp5523_setup, | |
81 | .release_resources = lp5523_release, | |
82 | .enable = lp5523_enable, | |
83 | }; |