Commit | Line | Data |
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5991e154 SO |
1 | Kernel driver for lp5521 |
2 | ======================== | |
3 | ||
4 | * National Semiconductor LP5521 led driver chip | |
5 | * Datasheet: http://www.national.com/pf/LP/LP5521.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 | ||
13 | LP5521 can drive up to 3 channels. Leds can be controlled directly via | |
14 | the led class control interface. Channels have generic names: | |
15 | lp5521:channelx, where x is 0 .. 2 | |
16 | ||
17 | All three channels can be also controlled using the engine micro programs. | |
18 | More details of the instructions can be found from the public data sheet. | |
19 | ||
20 | Control interface for the engines: | |
21 | x is 1 .. 3 | |
22 | enginex_mode : disabled, load, run | |
23 | enginex_load : store program (visible only in engine load mode) | |
24 | ||
25 | Example (start to blink the channel 2 led): | |
26 | cd /sys/class/leds/lp5521:channel2/device | |
27 | echo "load" > engine3_mode | |
28 | echo "037f4d0003ff6000" > engine3_load | |
29 | echo "run" > engine3_mode | |
30 | ||
31 | stop the engine: | |
32 | echo "disabled" > engine3_mode | |
33 | ||
34 | sysfs contains a selftest entry. | |
35 | The test communicates with the chip and checks that | |
36 | the clock mode is automatically set to the requested one. | |
37 | ||
38 | Each channel has its own led current settings. | |
39 | /sys/class/leds/lp5521:channel0/led_current - RW | |
40 | /sys/class/leds/lp5521:channel0/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 2. | |
46 | ||
47 | static struct lp5521_led_config lp5521_led_config[] = { | |
48 | { | |
49 | .chan_nr = 0, | |
50 | .led_current = 50, | |
51 | .max_current = 130, | |
52 | }, { | |
53 | .chan_nr = 1, | |
54 | .led_current = 0, | |
55 | .max_current = 130, | |
56 | }, { | |
57 | .chan_nr = 2, | |
58 | .led_current = 0, | |
59 | .max_current = 130, | |
60 | } | |
61 | }; | |
62 | ||
63 | static int lp5521_setup(void) | |
64 | { | |
65 | /* setup HW resources */ | |
66 | } | |
67 | ||
68 | static void lp5521_release(void) | |
69 | { | |
70 | /* Release HW resources */ | |
71 | } | |
72 | ||
73 | static void lp5521_enable(bool state) | |
74 | { | |
75 | /* Control of chip enable signal */ | |
76 | } | |
77 | ||
78 | static struct lp5521_platform_data lp5521_platform_data = { | |
79 | .led_config = lp5521_led_config, | |
80 | .num_channels = ARRAY_SIZE(lp5521_led_config), | |
81 | .clock_mode = LP5521_CLOCK_EXT, | |
82 | .setup_resources = lp5521_setup, | |
83 | .release_resources = lp5521_release, | |
84 | .enable = lp5521_enable, | |
85 | }; | |
86 | ||
87 | If the current is set to 0 in the platform data, that channel is | |
88 | disabled and it is not visible in the sysfs. |