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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 | |
94b43b67 KM |
13 | the led class control interface. |
14 | The name of each channel is configurable in the platform data - name and label. | |
15 | There are three options to make the channel name. | |
16 | ||
17 | a) Define the 'name' in the platform data | |
18 | To make specific channel name, then use 'name' platform data. | |
19 | /sys/class/leds/R1 (name: 'R1') | |
20 | /sys/class/leds/B1 (name: 'B1') | |
21 | ||
22 | b) Use the 'label' with no 'name' field | |
23 | For one device name with channel number, then use 'label'. | |
24 | /sys/class/leds/RGB:channelN (label: 'RGB', N: 0 ~ 8) | |
25 | ||
26 | c) Default | |
27 | If both fields are NULL, 'lp5523' is used by default. | |
28 | /sys/class/leds/lp5523:channelN (N: 0 ~ 8) | |
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29 | |
30 | The chip provides 3 engines. Each engine can control channels without | |
31 | interaction from the main CPU. Details of the micro engine code can be found | |
32 | from the public data sheet. Leds can be muxed to different channels. | |
33 | ||
34 | Control interface for the engines: | |
35 | x is 1 .. 3 | |
36 | enginex_mode : disabled, load, run | |
37 | enginex_load : microcode load (visible only in load mode) | |
38 | enginex_leds : led mux control (visible only in load mode) | |
39 | ||
40 | cd /sys/class/leds/lp5523:channel2/device | |
41 | echo "load" > engine3_mode | |
42 | echo "9d80400004ff05ff437f0000" > engine3_load | |
43 | echo "111111111" > engine3_leds | |
44 | echo "run" > engine3_mode | |
45 | ||
46 | sysfs contains a selftest entry. It measures each channel | |
47 | voltage level and checks if it looks reasonable. If the level is too high, | |
48 | the led is missing; if the level is too low, there is a short circuit. | |
49 | ||
50 | Selftest uses always the current from the platform data. | |
51 | ||
52 | Each channel contains led current settings. | |
53 | /sys/class/leds/lp5523:channel2/led_current - RW | |
54 | /sys/class/leds/lp5523:channel2/max_current - RO | |
55 | Format: 10x mA i.e 10 means 1.0 mA | |
56 | ||
57 | Example platform data: | |
58 | ||
59 | Note - chan_nr can have values between 0 and 8. | |
60 | ||
61 | static struct lp5523_led_config lp5523_led_config[] = { | |
62 | { | |
94b43b67 | 63 | .name = "D1", |
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64 | .chan_nr = 0, |
65 | .led_current = 50, | |
66 | .max_current = 130, | |
67 | }, | |
68 | ... | |
94b43b67 | 69 | { |
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70 | .chan_nr = 8, |
71 | .led_current = 50, | |
72 | .max_current = 130, | |
73 | } | |
74 | }; | |
75 | ||
76 | static int lp5523_setup(void) | |
77 | { | |
78 | /* Setup HW resources */ | |
79 | } | |
80 | ||
81 | static void lp5523_release(void) | |
82 | { | |
83 | /* Release HW resources */ | |
84 | } | |
85 | ||
86 | static void lp5523_enable(bool state) | |
87 | { | |
88 | /* Control chip enable signal */ | |
89 | } | |
90 | ||
91 | static struct lp5523_platform_data lp5523_platform_data = { | |
92 | .led_config = lp5523_led_config, | |
93 | .num_channels = ARRAY_SIZE(lp5523_led_config), | |
94 | .clock_mode = LP5523_CLOCK_EXT, | |
95 | .setup_resources = lp5523_setup, | |
96 | .release_resources = lp5523_release, | |
97 | .enable = lp5523_enable, | |
98 | }; |