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Documentation / leds / leds-lp5523.txt




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Based on kernel version 4.7.2. Page generated on 2016-08-22 22:46 EST.

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.
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)
29	
30	LP5523 has the internal program memory for running various LED patterns.
31	There are two ways to run LED patterns.
32	
33	1) Legacy interface - enginex_mode, enginex_load and enginex_leds
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	  To stop the engine:
47	  echo "disabled" > engine3_mode
48	
49	2) Firmware interface - LP55xx common interface
50	  For the details, please refer to 'firmware' section in leds-lp55xx.txt
51	
52	LP5523 has three master faders. If a channel is mapped to one of
53	the master faders, its output is dimmed based on the value of the master
54	fader.
55	
56	For example,
57	
58	  echo "123000123" > master_fader_leds
59	
60	creates the following channel-fader mappings:
61	
62	  channel 0,6 to master_fader1
63	  channel 1,7 to master_fader2
64	  channel 2,8 to master_fader3
65	
66	Then, to have 25% of the original output on channel 0,6:
67	
68	  echo 64 > master_fader1
69	
70	To have 0% of the original output (i.e. no output) channel 1,7:
71	
72	  echo 0 > master_fader2
73	
74	To have 100% of the original output (i.e. no dimming) on channel 2,8:
75	
76	  echo 255 > master_fader3
77	
78	To clear all master fader controls:
79	
80	  echo "000000000" > master_fader_leds
81	
82	Selftest uses always the current from the platform data.
83	
84	Each channel contains led current settings.
85	/sys/class/leds/lp5523:channel2/led_current - RW
86	/sys/class/leds/lp5523:channel2/max_current - RO
87	Format: 10x mA i.e 10 means 1.0 mA
88	
89	Example platform data:
90	
91	Note - chan_nr can have values between 0 and 8.
92	
93	static struct lp55xx_led_config lp5523_led_config[] = {
94	        {
95			.name		= "D1",
96	                .chan_nr        = 0,
97	                .led_current    = 50,
98			.max_current    = 130,
99	        },
100	...
101	        {
102	                .chan_nr        = 8,
103	                .led_current    = 50,
104			.max_current    = 130,
105	        }
106	};
107	
108	static int lp5523_setup(void)
109	{
110		/* Setup HW resources */
111	}
112	
113	static void lp5523_release(void)
114	{
115		/* Release HW resources */
116	}
117	
118	static void lp5523_enable(bool state)
119	{
120		/* Control chip enable signal */
121	}
122	
123	static struct lp55xx_platform_data lp5523_platform_data = {
124	        .led_config     = lp5523_led_config,
125	        .num_channels   = ARRAY_SIZE(lp5523_led_config),
126	        .clock_mode     = LP55XX_CLOCK_EXT,
127	        .setup_resources   = lp5523_setup,
128	        .release_resources = lp5523_release,
129	        .enable            = lp5523_enable,
130	};
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