1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * TI LP8501 9 channel LED Driver 4 * 5 * Copyright (C) 2013 Texas Instruments 6 * 7 * Author: Milo(Woogyom) Kim <milo.kim@ti.com> 8 */ 9 10 #include <linux/delay.h> 11 #include <linux/firmware.h> 12 #include <linux/i2c.h> 13 #include <linux/init.h> 14 #include <linux/leds.h> 15 #include <linux/module.h> 16 #include <linux/mutex.h> 17 #include <linux/of.h> 18 #include <linux/platform_data/leds-lp55xx.h> 19 #include <linux/slab.h> 20 21 #include "leds-lp55xx-common.h" 22 23 #define LP8501_PROGRAM_LENGTH 32 24 #define LP8501_PAGES_PER_ENGINE 1 25 #define LP8501_MAX_LEDS 9 26 27 /* Registers */ 28 #define LP8501_REG_ENABLE 0x00 29 #define LP8501_ENABLE BIT(6) 30 #define LP8501_EXEC_M 0x3F 31 #define LP8501_EXEC_ENG1_M 0x30 32 #define LP8501_EXEC_ENG2_M 0x0C 33 #define LP8501_EXEC_ENG3_M 0x03 34 #define LP8501_RUN_ENG1 0x20 35 #define LP8501_RUN_ENG2 0x08 36 #define LP8501_RUN_ENG3 0x02 37 38 #define LP8501_REG_OP_MODE 0x01 39 #define LP8501_MODE_ENG1_M 0x30 40 #define LP8501_MODE_ENG2_M 0x0C 41 #define LP8501_MODE_ENG3_M 0x03 42 #define LP8501_LOAD_ENG1 0x10 43 #define LP8501_LOAD_ENG2 0x04 44 #define LP8501_LOAD_ENG3 0x01 45 46 #define LP8501_REG_PWR_CONFIG 0x05 47 #define LP8501_PWR_CONFIG_M 0x03 48 49 #define LP8501_REG_LED_PWM_BASE 0x16 50 51 #define LP8501_REG_LED_CURRENT_BASE 0x26 52 53 #define LP8501_REG_CONFIG 0x36 54 #define LP8501_PWM_PSAVE BIT(7) 55 #define LP8501_AUTO_INC BIT(6) 56 #define LP8501_PWR_SAVE BIT(5) 57 #define LP8501_CP_MODE_MASK 0x18 58 #define LP8501_CP_MODE_SHIFT 3 59 #define LP8501_INT_CLK BIT(0) 60 #define LP8501_DEFAULT_CFG (LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE) 61 62 #define LP8501_REG_STATUS 0x3A 63 #define LP8501_ENGINE_BUSY BIT(4) 64 65 #define LP8501_REG_RESET 0x3D 66 #define LP8501_RESET 0xFF 67 68 #define LP8501_REG_PROG_PAGE_SEL 0x4F 69 #define LP8501_PAGE_ENG1 0 70 #define LP8501_PAGE_ENG2 1 71 #define LP8501_PAGE_ENG3 2 72 73 #define LP8501_REG_PROG_MEM 0x50 74 75 #define LP8501_ENG1_IS_LOADING(mode) \ 76 ((mode & LP8501_MODE_ENG1_M) == LP8501_LOAD_ENG1) 77 #define LP8501_ENG2_IS_LOADING(mode) \ 78 ((mode & LP8501_MODE_ENG2_M) == LP8501_LOAD_ENG2) 79 #define LP8501_ENG3_IS_LOADING(mode) \ 80 ((mode & LP8501_MODE_ENG3_M) == LP8501_LOAD_ENG3) 81 82 static inline void lp8501_wait_opmode_done(void) 83 { 84 usleep_range(1000, 2000); 85 } 86 87 static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current) 88 { 89 led->led_current = led_current; 90 lp55xx_write(led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr, 91 led_current); 92 } 93 94 static int lp8501_post_init_device(struct lp55xx_chip *chip) 95 { 96 int ret; 97 u8 val = LP8501_DEFAULT_CFG; 98 99 ret = lp55xx_write(chip, LP8501_REG_ENABLE, LP8501_ENABLE); 100 if (ret) 101 return ret; 102 103 /* Chip startup time is 500 us, 1 - 2 ms gives some margin */ 104 usleep_range(1000, 2000); 105 106 if (chip->pdata->clock_mode != LP55XX_CLOCK_EXT) 107 val |= LP8501_INT_CLK; 108 109 val |= (chip->pdata->charge_pump_mode << LP8501_CP_MODE_SHIFT) & LP8501_CP_MODE_MASK; 110 111 ret = lp55xx_write(chip, LP8501_REG_CONFIG, val); 112 if (ret) 113 return ret; 114 115 /* Power selection for each output */ 116 return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG, 117 LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel); 118 } 119 120 static void lp8501_turn_off_channels(struct lp55xx_chip *chip) 121 { 122 int i; 123 124 for (i = 0; i < LP8501_MAX_LEDS; i++) 125 lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0); 126 } 127 128 static void lp8501_run_engine(struct lp55xx_chip *chip, bool start) 129 { 130 int ret; 131 u8 mode; 132 u8 exec; 133 134 /* stop engine */ 135 if (!start) { 136 lp55xx_stop_all_engine(chip); 137 lp8501_turn_off_channels(chip); 138 return; 139 } 140 141 /* 142 * To run the engine, 143 * operation mode and enable register should updated at the same time 144 */ 145 146 ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode); 147 if (ret) 148 return; 149 150 ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec); 151 if (ret) 152 return; 153 154 /* change operation mode to RUN only when each engine is loading */ 155 if (LP8501_ENG1_IS_LOADING(mode)) { 156 mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1; 157 exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1; 158 } 159 160 if (LP8501_ENG2_IS_LOADING(mode)) { 161 mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2; 162 exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2; 163 } 164 165 if (LP8501_ENG3_IS_LOADING(mode)) { 166 mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3; 167 exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3; 168 } 169 170 lp55xx_write(chip, LP8501_REG_OP_MODE, mode); 171 lp8501_wait_opmode_done(); 172 173 lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec); 174 } 175 176 static int lp8501_update_program_memory(struct lp55xx_chip *chip, 177 const u8 *data, size_t size) 178 { 179 u8 pattern[LP8501_PROGRAM_LENGTH] = {0}; 180 unsigned cmd; 181 char c[3]; 182 int update_size; 183 int nrchars; 184 int offset = 0; 185 int ret; 186 int i; 187 188 /* clear program memory before updating */ 189 for (i = 0; i < LP8501_PROGRAM_LENGTH; i++) 190 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0); 191 192 i = 0; 193 while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) { 194 /* separate sscanfs because length is working only for %s */ 195 ret = sscanf(data + offset, "%2s%n ", c, &nrchars); 196 if (ret != 1) 197 goto err; 198 199 ret = sscanf(c, "%2x", &cmd); 200 if (ret != 1) 201 goto err; 202 203 pattern[i] = (u8)cmd; 204 offset += nrchars; 205 i++; 206 } 207 208 /* Each instruction is 16bit long. Check that length is even */ 209 if (i % 2) 210 goto err; 211 212 update_size = i; 213 for (i = 0; i < update_size; i++) 214 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]); 215 216 return 0; 217 218 err: 219 dev_err(&chip->cl->dev, "wrong pattern format\n"); 220 return -EINVAL; 221 } 222 223 static void lp8501_firmware_loaded(struct lp55xx_chip *chip) 224 { 225 const struct firmware *fw = chip->fw; 226 227 if (fw->size > LP8501_PROGRAM_LENGTH) { 228 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n", 229 fw->size); 230 return; 231 } 232 233 /* 234 * Program memory sequence 235 * 1) set engine mode to "LOAD" 236 * 2) write firmware data into program memory 237 */ 238 239 lp55xx_load_engine(chip); 240 lp8501_update_program_memory(chip, fw->data, fw->size); 241 } 242 243 static int lp8501_led_brightness(struct lp55xx_led *led) 244 { 245 struct lp55xx_chip *chip = led->chip; 246 int ret; 247 248 mutex_lock(&chip->lock); 249 ret = lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr, 250 led->brightness); 251 mutex_unlock(&chip->lock); 252 253 return ret; 254 } 255 256 /* Chip specific configurations */ 257 static struct lp55xx_device_config lp8501_cfg = { 258 .reg_op_mode = { 259 .addr = LP8501_REG_OP_MODE, 260 }, 261 .engine_busy = { 262 .addr = LP8501_REG_STATUS, 263 .mask = LP8501_ENGINE_BUSY, 264 }, 265 .reset = { 266 .addr = LP8501_REG_RESET, 267 .val = LP8501_RESET, 268 }, 269 .enable = { 270 .addr = LP8501_REG_ENABLE, 271 .val = LP8501_ENABLE, 272 }, 273 .pages_per_engine = LP8501_PAGES_PER_ENGINE, 274 .max_channel = LP8501_MAX_LEDS, 275 .post_init_device = lp8501_post_init_device, 276 .brightness_fn = lp8501_led_brightness, 277 .set_led_current = lp8501_set_led_current, 278 .firmware_cb = lp8501_firmware_loaded, 279 .run_engine = lp8501_run_engine, 280 }; 281 282 static const struct i2c_device_id lp8501_id[] = { 283 { "lp8501", .driver_data = (kernel_ulong_t)&lp8501_cfg, }, 284 { } 285 }; 286 MODULE_DEVICE_TABLE(i2c, lp8501_id); 287 288 static const struct of_device_id of_lp8501_leds_match[] = { 289 { .compatible = "ti,lp8501", .data = &lp8501_cfg, }, 290 {}, 291 }; 292 293 MODULE_DEVICE_TABLE(of, of_lp8501_leds_match); 294 295 static struct i2c_driver lp8501_driver = { 296 .driver = { 297 .name = "lp8501", 298 .of_match_table = of_lp8501_leds_match, 299 }, 300 .probe = lp55xx_probe, 301 .remove = lp55xx_remove, 302 .id_table = lp8501_id, 303 }; 304 305 module_i2c_driver(lp8501_driver); 306 307 MODULE_DESCRIPTION("Texas Instruments LP8501 LED driver"); 308 MODULE_AUTHOR("Milo Kim"); 309 MODULE_LICENSE("GPL"); 310