1================================================= 2LP5521/LP5523/LP55231/LP5562/LP8501 Common Driver 3================================================= 4 5Authors: Milo(Woogyom) Kim <milo.kim@ti.com> 6 7Description 8----------- 9LP5521, LP5523/55231, LP5562 and LP8501 have common features as below. 10 11 Register access via the I2C 12 Device initialization/deinitialization 13 Create LED class devices for multiple output channels 14 Device attributes for user-space interface 15 Program memory for running LED patterns 16 17The LP55xx common driver provides these features using exported functions. 18 19 lp55xx_init_device() / lp55xx_deinit_device() 20 lp55xx_register_leds() / lp55xx_unregister_leds() 21 lp55xx_regsister_sysfs() / lp55xx_unregister_sysfs() 22 23( Driver Structure Data ) 24 25In lp55xx common driver, two different data structure is used. 26 27* lp55xx_led 28 control multi output LED channels such as led current, channel index. 29* lp55xx_chip 30 general chip control such like the I2C and platform data. 31 32For example, LP5521 has maximum 3 LED channels. 33LP5523/55231 has 9 output channels:: 34 35 lp55xx_chip for LP5521 ... lp55xx_led #1 36 lp55xx_led #2 37 lp55xx_led #3 38 39 lp55xx_chip for LP5523 ... lp55xx_led #1 40 lp55xx_led #2 41 . 42 . 43 lp55xx_led #9 44 45( Chip Dependent Code ) 46 47To support device specific configurations, special structure 48'lpxx_device_config' is used. 49 50 - Maximum number of channels 51 - Reset command, chip enable command 52 - Chip specific initialization 53 - Brightness control register access 54 - Setting LED output current 55 - Program memory address access for running patterns 56 - Additional device specific attributes 57 58( Firmware Interface ) 59 60LP55xx family devices have the internal program memory for running 61various LED patterns. 62 63This pattern data is saved as a file in the user-land or 64hex byte string is written into the memory through the I2C. 65 66LP55xx common driver supports the firmware interface. 67 68LP55xx chips have three program engines. 69 70To load and run the pattern, the programming sequence is following. 71 72 (1) Select an engine number (1/2/3) 73 (2) Mode change to load 74 (3) Write pattern data into selected area 75 (4) Mode change to run 76 77The LP55xx common driver provides simple interfaces as below. 78 79select_engine: 80 Select which engine is used for running program 81run_engine: 82 Start program which is loaded via the firmware interface 83firmware: 84 Load program data 85 86In case of LP5523, one more command is required, 'enginex_leds'. 87It is used for selecting LED output(s) at each engine number. 88In more details, please refer to 'leds-lp5523.txt'. 89 90For example, run blinking pattern in engine #1 of LP5521:: 91 92 echo 1 > /sys/bus/i2c/devices/xxxx/select_engine 93 echo 1 > /sys/class/firmware/lp5521/loading 94 echo "4000600040FF6000" > /sys/class/firmware/lp5521/data 95 echo 0 > /sys/class/firmware/lp5521/loading 96 echo 1 > /sys/bus/i2c/devices/xxxx/run_engine 97 98For example, run blinking pattern in engine #3 of LP55231 99 100Two LEDs are configured as pattern output channels:: 101 102 echo 3 > /sys/bus/i2c/devices/xxxx/select_engine 103 echo 1 > /sys/class/firmware/lp55231/loading 104 echo "9d0740ff7e0040007e00a0010000" > /sys/class/firmware/lp55231/data 105 echo 0 > /sys/class/firmware/lp55231/loading 106 echo "000001100" > /sys/bus/i2c/devices/xxxx/engine3_leds 107 echo 1 > /sys/bus/i2c/devices/xxxx/run_engine 108 109To start blinking patterns in engine #2 and #3 simultaneously:: 110 111 for idx in 2 3 112 do 113 echo $idx > /sys/class/leds/red/device/select_engine 114 sleep 0.1 115 echo 1 > /sys/class/firmware/lp5521/loading 116 echo "4000600040FF6000" > /sys/class/firmware/lp5521/data 117 echo 0 > /sys/class/firmware/lp5521/loading 118 done 119 echo 1 > /sys/class/leds/red/device/run_engine 120 121Here is another example for LP5523. 122 123Full LED strings are selected by 'engine2_leds':: 124 125 echo 2 > /sys/bus/i2c/devices/xxxx/select_engine 126 echo 1 > /sys/class/firmware/lp5523/loading 127 echo "9d80400004ff05ff437f0000" > /sys/class/firmware/lp5523/data 128 echo 0 > /sys/class/firmware/lp5523/loading 129 echo "111111111" > /sys/bus/i2c/devices/xxxx/engine2_leds 130 echo 1 > /sys/bus/i2c/devices/xxxx/run_engine 131 132As soon as 'loading' is set to 0, registered callback is called. 133Inside the callback, the selected engine is loaded and memory is updated. 134To run programmed pattern, 'run_engine' attribute should be enabled. 135 136The pattern sequence of LP8501 is similar to LP5523. 137 138However pattern data is specific. 139 140Ex 1) Engine 1 is used:: 141 142 echo 1 > /sys/bus/i2c/devices/xxxx/select_engine 143 echo 1 > /sys/class/firmware/lp8501/loading 144 echo "9d0140ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data 145 echo 0 > /sys/class/firmware/lp8501/loading 146 echo 1 > /sys/bus/i2c/devices/xxxx/run_engine 147 148Ex 2) Engine 2 and 3 are used at the same time:: 149 150 echo 2 > /sys/bus/i2c/devices/xxxx/select_engine 151 sleep 1 152 echo 1 > /sys/class/firmware/lp8501/loading 153 echo "9d0140ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data 154 echo 0 > /sys/class/firmware/lp8501/loading 155 sleep 1 156 echo 3 > /sys/bus/i2c/devices/xxxx/select_engine 157 sleep 1 158 echo 1 > /sys/class/firmware/lp8501/loading 159 echo "9d0340ff7e0040007e00a001c000" > /sys/class/firmware/lp8501/data 160 echo 0 > /sys/class/firmware/lp8501/loading 161 sleep 1 162 echo 1 > /sys/class/leds/d1/device/run_engine 163 164( 'run_engine' and 'firmware_cb' ) 165 166The sequence of running the program data is common. 167 168But each device has own specific register addresses for commands. 169 170To support this, 'run_engine' and 'firmware_cb' are configurable in each driver. 171 172run_engine: 173 Control the selected engine 174firmware_cb: 175 The callback function after loading the firmware is done. 176 177 Chip specific commands for loading and updating program memory. 178 179( Predefined pattern data ) 180 181Without the firmware interface, LP55xx driver provides another method for 182loading a LED pattern. That is 'predefined' pattern. 183 184A predefined pattern is defined in the platform data and load it(or them) 185via the sysfs if needed. 186 187To use the predefined pattern concept, 'patterns' and 'num_patterns' should be 188configured. 189 190Example of predefined pattern data:: 191 192 /* mode_1: blinking data */ 193 static const u8 mode_1[] = { 194 0x40, 0x00, 0x60, 0x00, 0x40, 0xFF, 0x60, 0x00, 195 }; 196 197 /* mode_2: always on */ 198 static const u8 mode_2[] = { 0x40, 0xFF, }; 199 200 struct lp55xx_predef_pattern board_led_patterns[] = { 201 { 202 .r = mode_1, 203 .size_r = ARRAY_SIZE(mode_1), 204 }, 205 { 206 .b = mode_2, 207 .size_b = ARRAY_SIZE(mode_2), 208 }, 209 } 210 211 struct lp55xx_platform_data lp5562_pdata = { 212 ... 213 .patterns = board_led_patterns, 214 .num_patterns = ARRAY_SIZE(board_led_patterns), 215 }; 216 217Then, mode_1 and mode_2 can be run via through the sysfs:: 218 219 echo 1 > /sys/bus/i2c/devices/xxxx/led_pattern # red blinking LED pattern 220 echo 2 > /sys/bus/i2c/devices/xxxx/led_pattern # blue LED always on 221 222To stop running pattern:: 223 224 echo 0 > /sys/bus/i2c/devices/xxxx/led_pattern 225