Commit | Line | Data |
---|---|---|
c0285f8c MWK |
1 | LP5521/LP5523/LP55231 Common Driver |
2 | =================================== | |
3 | ||
4 | Authors: Milo(Woogyom) Kim <milo.kim@ti.com> | |
5 | ||
6 | Description | |
7 | ----------- | |
8 | LP5521, LP5523/55231 have common features as below. | |
9 | ||
10 | Register access via the I2C | |
11 | Device initialization/deinitialization | |
12 | Create LED class devices for multiple output channels | |
13 | Device attributes for user-space interface | |
14 | Program memory for running LED patterns | |
15 | ||
16 | The LP55xx common driver provides these features using exported functions. | |
17 | lp55xx_init_device() / lp55xx_deinit_device() | |
18 | lp55xx_register_leds() / lp55xx_unregister_leds() | |
19 | lp55xx_regsister_sysfs() / lp55xx_unregister_sysfs() | |
20 | ||
21 | ( Driver Structure Data ) | |
22 | ||
23 | In lp55xx common driver, two different data structure is used. | |
24 | ||
25 | o lp55xx_led | |
26 | control multi output LED channels such as led current, channel index. | |
27 | o lp55xx_chip | |
28 | general chip control such like the I2C and platform data. | |
29 | ||
30 | For example, LP5521 has maximum 3 LED channels. | |
31 | LP5523/55231 has 9 output channels. | |
32 | ||
33 | lp55xx_chip for LP5521 ... lp55xx_led #1 | |
34 | lp55xx_led #2 | |
35 | lp55xx_led #3 | |
36 | ||
37 | lp55xx_chip for LP5523 ... lp55xx_led #1 | |
38 | lp55xx_led #2 | |
39 | . | |
40 | . | |
41 | lp55xx_led #9 | |
42 | ||
43 | ( Chip Dependent Code ) | |
44 | ||
45 | To support device specific configurations, special structure | |
46 | 'lpxx_device_config' is used. | |
47 | ||
48 | Maximum number of channels | |
49 | Reset command, chip enable command | |
50 | Chip specific initialization | |
51 | Brightness control register access | |
52 | Setting LED output current | |
53 | Program memory address access for running patterns | |
54 | Additional device specific attributes | |
55 | ||
56 | ( Firmware Interface ) | |
57 | ||
58 | LP55xx family devices have the internal program memory for running | |
59 | various LED patterns. | |
60 | This pattern data is saved as a file in the user-land or | |
61 | hex byte string is written into the memory through the I2C. | |
62 | LP55xx common driver supports the firmware interface. | |
63 | ||
64 | LP55xx chips have three program engines. | |
65 | To load and run the pattern, the programming sequence is following. | |
66 | (1) Select an engine number (1/2/3) | |
67 | (2) Mode change to load | |
68 | (3) Write pattern data into selected area | |
69 | (4) Mode change to run | |
70 | ||
71 | The LP55xx common driver provides simple interfaces as below. | |
72 | select_engine : Select which engine is used for running program | |
73 | run_engine : Start program which is loaded via the firmware interface | |
74 | firmware : Load program data | |
75 | ||
76 | For example, run blinking pattern in engine #1 of LP5521 | |
77 | echo 1 > /sys/bus/i2c/devices/xxxx/select_engine | |
78 | echo 1 > /sys/class/firmware/lp5521/loading | |
79 | echo "4000600040FF6000" > /sys/class/firmware/lp5521/data | |
80 | echo 0 > /sys/class/firmware/lp5521/loading | |
81 | echo 1 > /sys/bus/i2c/devices/xxxx/run_engine | |
82 | ||
83 | For example, run blinking pattern in engine #3 of LP55231 | |
84 | echo 3 > /sys/bus/i2c/devices/xxxx/select_engine | |
85 | echo 1 > /sys/class/firmware/lp55231/loading | |
86 | echo "9d0740ff7e0040007e00a0010000" > /sys/class/firmware/lp55231/data | |
87 | echo 0 > /sys/class/firmware/lp55231/loading | |
88 | echo 1 > /sys/bus/i2c/devices/xxxx/run_engine | |
89 | ||
90 | To start blinking patterns in engine #2 and #3 simultaneously, | |
91 | for idx in 2 3 | |
92 | do | |
93 | echo $idx > /sys/class/leds/red/device/select_engine | |
94 | sleep 0.1 | |
95 | echo 1 > /sys/class/firmware/lp5521/loading | |
96 | echo "4000600040FF6000" > /sys/class/firmware/lp5521/data | |
97 | echo 0 > /sys/class/firmware/lp5521/loading | |
98 | done | |
99 | echo 1 > /sys/class/leds/red/device/run_engine | |
100 | ||
101 | Here is another example for LP5523. | |
102 | echo 2 > /sys/bus/i2c/devices/xxxx/select_engine | |
103 | echo 1 > /sys/class/firmware/lp5523/loading | |
104 | echo "9d80400004ff05ff437f0000" > /sys/class/firmware/lp5523/data | |
105 | echo 0 > /sys/class/firmware/lp5523/loading | |
106 | echo 1 > /sys/bus/i2c/devices/xxxx/run_engine | |
107 | ||
108 | As soon as 'loading' is set to 0, registered callback is called. | |
109 | Inside the callback, the selected engine is loaded and memory is updated. | |
110 | To run programmed pattern, 'run_engine' attribute should be enabled. | |
111 | ||
112 | ( 'run_engine' and 'firmware_cb' ) | |
113 | The sequence of running the program data is common. | |
114 | But each device has own specific register addresses for commands. | |
115 | To support this, 'run_engine' and 'firmware_cb' are configurable in each driver. | |
116 | run_engine : Control the selected engine | |
117 | firmware_cb : The callback function after loading the firmware is done. | |
118 | Chip specific commands for loading and updating program memory. |