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1 | LP5521/LP5523/LP55231/LP5562/LP8501 Common Driver |
2 | ================================================= | |
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3 | |
4 | Authors: Milo(Woogyom) Kim <milo.kim@ti.com> | |
5 | ||
6 | Description | |
7 | ----------- | |
33b3a561 | 8 | LP5521, LP5523/55231, LP5562 and LP8501 have common features as below. |
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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 | ||
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76 | In case of LP5523, one more command is required, 'enginex_leds'. |
77 | It is used for selecting LED output(s) at each engine number. | |
78 | In more details, please refer to 'leds-lp5523.txt'. | |
79 | ||
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80 | For example, run blinking pattern in engine #1 of LP5521 |
81 | echo 1 > /sys/bus/i2c/devices/xxxx/select_engine | |
82 | echo 1 > /sys/class/firmware/lp5521/loading | |
83 | echo "4000600040FF6000" > /sys/class/firmware/lp5521/data | |
84 | echo 0 > /sys/class/firmware/lp5521/loading | |
85 | echo 1 > /sys/bus/i2c/devices/xxxx/run_engine | |
86 | ||
87 | For example, run blinking pattern in engine #3 of LP55231 | |
93ad8a1d | 88 | Two LEDs are configured as pattern output channels. |
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89 | echo 3 > /sys/bus/i2c/devices/xxxx/select_engine |
90 | echo 1 > /sys/class/firmware/lp55231/loading | |
91 | echo "9d0740ff7e0040007e00a0010000" > /sys/class/firmware/lp55231/data | |
92 | echo 0 > /sys/class/firmware/lp55231/loading | |
93ad8a1d | 93 | echo "000001100" > /sys/bus/i2c/devices/xxxx/engine3_leds |
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94 | echo 1 > /sys/bus/i2c/devices/xxxx/run_engine |
95 | ||
96 | To start blinking patterns in engine #2 and #3 simultaneously, | |
97 | for idx in 2 3 | |
98 | do | |
99 | echo $idx > /sys/class/leds/red/device/select_engine | |
100 | sleep 0.1 | |
101 | echo 1 > /sys/class/firmware/lp5521/loading | |
102 | echo "4000600040FF6000" > /sys/class/firmware/lp5521/data | |
103 | echo 0 > /sys/class/firmware/lp5521/loading | |
104 | done | |
105 | echo 1 > /sys/class/leds/red/device/run_engine | |
106 | ||
107 | Here is another example for LP5523. | |
93ad8a1d | 108 | Full LED strings are selected by 'engine2_leds'. |
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109 | echo 2 > /sys/bus/i2c/devices/xxxx/select_engine |
110 | echo 1 > /sys/class/firmware/lp5523/loading | |
111 | echo "9d80400004ff05ff437f0000" > /sys/class/firmware/lp5523/data | |
112 | echo 0 > /sys/class/firmware/lp5523/loading | |
93ad8a1d | 113 | echo "111111111" > /sys/bus/i2c/devices/xxxx/engine2_leds |
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114 | echo 1 > /sys/bus/i2c/devices/xxxx/run_engine |
115 | ||
116 | As soon as 'loading' is set to 0, registered callback is called. | |
117 | Inside the callback, the selected engine is loaded and memory is updated. | |
118 | To run programmed pattern, 'run_engine' attribute should be enabled. | |
119 | ||
93ad8a1d | 120 | The pattern sqeuence of LP8501 is similar to LP5523. |
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121 | However pattern data is specific. |
122 | Ex 1) Engine 1 is used | |
123 | echo 1 > /sys/bus/i2c/devices/xxxx/select_engine | |
124 | echo 1 > /sys/class/firmware/lp8501/loading | |
125 | echo "9d0140ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data | |
126 | echo 0 > /sys/class/firmware/lp8501/loading | |
127 | echo 1 > /sys/bus/i2c/devices/xxxx/run_engine | |
128 | ||
129 | Ex 2) Engine 2 and 3 are used at the same time | |
130 | echo 2 > /sys/bus/i2c/devices/xxxx/select_engine | |
131 | sleep 1 | |
132 | echo 1 > /sys/class/firmware/lp8501/loading | |
133 | echo "9d0140ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data | |
134 | echo 0 > /sys/class/firmware/lp8501/loading | |
135 | sleep 1 | |
136 | echo 3 > /sys/bus/i2c/devices/xxxx/select_engine | |
137 | sleep 1 | |
138 | echo 1 > /sys/class/firmware/lp8501/loading | |
139 | echo "9d0340ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data | |
140 | echo 0 > /sys/class/firmware/lp8501/loading | |
141 | sleep 1 | |
142 | echo 1 > /sys/class/leds/d1/device/run_engine | |
143 | ||
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144 | ( 'run_engine' and 'firmware_cb' ) |
145 | The sequence of running the program data is common. | |
146 | But each device has own specific register addresses for commands. | |
147 | To support this, 'run_engine' and 'firmware_cb' are configurable in each driver. | |
148 | run_engine : Control the selected engine | |
149 | firmware_cb : The callback function after loading the firmware is done. | |
150 | Chip specific commands for loading and updating program memory. | |
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151 | |
152 | ( Predefined pattern data ) | |
153 | ||
154 | Without the firmware interface, LP55xx driver provides another method for | |
155 | loading a LED pattern. That is 'predefined' pattern. | |
156 | A predefined pattern is defined in the platform data and load it(or them) | |
157 | via the sysfs if needed. | |
158 | To use the predefined pattern concept, 'patterns' and 'num_patterns' should be | |
159 | configured. | |
160 | ||
161 | Example of predefined pattern data: | |
162 | ||
163 | /* mode_1: blinking data */ | |
164 | static const u8 mode_1[] = { | |
165 | 0x40, 0x00, 0x60, 0x00, 0x40, 0xFF, 0x60, 0x00, | |
166 | }; | |
167 | ||
168 | /* mode_2: always on */ | |
169 | static const u8 mode_2[] = { 0x40, 0xFF, }; | |
170 | ||
171 | struct lp55xx_predef_pattern board_led_patterns[] = { | |
172 | { | |
173 | .r = mode_1, | |
174 | .size_r = ARRAY_SIZE(mode_1), | |
175 | }, | |
176 | { | |
177 | .b = mode_2, | |
178 | .size_b = ARRAY_SIZE(mode_2), | |
179 | }, | |
180 | } | |
181 | ||
182 | struct lp55xx_platform_data lp5562_pdata = { | |
183 | ... | |
184 | .patterns = board_led_patterns, | |
185 | .num_patterns = ARRAY_SIZE(board_led_patterns), | |
186 | }; | |
187 | ||
188 | Then, mode_1 and mode_2 can be run via through the sysfs. | |
189 | ||
190 | echo 1 > /sys/bus/i2c/devices/xxxx/led_pattern # red blinking LED pattern | |
191 | echo 2 > /sys/bus/i2c/devices/xxxx/led_pattern # blue LED always on | |
192 | ||
193 | To stop running pattern, | |
194 | echo 0 > /sys/bus/i2c/devices/xxxx/led_pattern |