Kim, Milo | 33b3a56 | 2013-07-09 02:11:37 -0700 | [diff] [blame] | 1 | LP5521/LP5523/LP55231/LP5562/LP8501 Common Driver |
| 2 | ================================================= |
Milo(Woogyom) Kim | c0285f8 | 2013-02-05 20:22:48 +0900 | [diff] [blame] | 3 | |
| 4 | Authors: Milo(Woogyom) Kim <milo.kim@ti.com> |
| 5 | |
| 6 | Description |
| 7 | ----------- |
Kim, Milo | 33b3a56 | 2013-07-09 02:11:37 -0700 | [diff] [blame] | 8 | LP5521, LP5523/55231, LP5562 and LP8501 have common features as below. |
Milo(Woogyom) Kim | c0285f8 | 2013-02-05 20:22:48 +0900 | [diff] [blame] | 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 | |
Milo Kim | 93ad8a1 | 2013-11-20 22:14:34 -0800 | [diff] [blame^] | 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 | |
Milo(Woogyom) Kim | c0285f8 | 2013-02-05 20:22:48 +0900 | [diff] [blame] | 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 |
Milo Kim | 93ad8a1 | 2013-11-20 22:14:34 -0800 | [diff] [blame^] | 88 | Two LEDs are configured as pattern output channels. |
Milo(Woogyom) Kim | c0285f8 | 2013-02-05 20:22:48 +0900 | [diff] [blame] | 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 |
Milo Kim | 93ad8a1 | 2013-11-20 22:14:34 -0800 | [diff] [blame^] | 93 | echo "000001100" > /sys/bus/i2c/devices/xxxx/engine3_leds |
Milo(Woogyom) Kim | c0285f8 | 2013-02-05 20:22:48 +0900 | [diff] [blame] | 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. |
Milo Kim | 93ad8a1 | 2013-11-20 22:14:34 -0800 | [diff] [blame^] | 108 | Full LED strings are selected by 'engine2_leds'. |
Milo(Woogyom) Kim | c0285f8 | 2013-02-05 20:22:48 +0900 | [diff] [blame] | 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 |
Milo Kim | 93ad8a1 | 2013-11-20 22:14:34 -0800 | [diff] [blame^] | 113 | echo "111111111" > /sys/bus/i2c/devices/xxxx/engine2_leds |
Milo(Woogyom) Kim | c0285f8 | 2013-02-05 20:22:48 +0900 | [diff] [blame] | 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 | |
Milo Kim | 93ad8a1 | 2013-11-20 22:14:34 -0800 | [diff] [blame^] | 120 | The pattern sqeuence of LP8501 is similar to LP5523. |
Kim, Milo | 33b3a56 | 2013-07-09 02:11:37 -0700 | [diff] [blame] | 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 | |
Milo(Woogyom) Kim | c0285f8 | 2013-02-05 20:22:48 +0900 | [diff] [blame] | 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. |
Kim, Milo | ff45262a | 2013-02-18 21:10:14 -0800 | [diff] [blame] | 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 |