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_MAX_LEDS 9 25 26 /* Registers */ 27 #define LP8501_REG_ENABLE 0x00 28 #define LP8501_ENABLE BIT(6) 29 #define LP8501_EXEC_M 0x3F 30 #define LP8501_EXEC_ENG1_M 0x30 31 #define LP8501_EXEC_ENG2_M 0x0C 32 #define LP8501_EXEC_ENG3_M 0x03 33 #define LP8501_RUN_ENG1 0x20 34 #define LP8501_RUN_ENG2 0x08 35 #define LP8501_RUN_ENG3 0x02 36 37 #define LP8501_REG_OP_MODE 0x01 38 #define LP8501_MODE_ENG1_M 0x30 39 #define LP8501_MODE_ENG2_M 0x0C 40 #define LP8501_MODE_ENG3_M 0x03 41 #define LP8501_LOAD_ENG1 0x10 42 #define LP8501_LOAD_ENG2 0x04 43 #define LP8501_LOAD_ENG3 0x01 44 45 #define LP8501_REG_PWR_CONFIG 0x05 46 #define LP8501_PWR_CONFIG_M 0x03 47 48 #define LP8501_REG_LED_PWM_BASE 0x16 49 50 #define LP8501_REG_LED_CURRENT_BASE 0x26 51 52 #define LP8501_REG_CONFIG 0x36 53 #define LP8501_PWM_PSAVE BIT(7) 54 #define LP8501_AUTO_INC BIT(6) 55 #define LP8501_PWR_SAVE BIT(5) 56 #define LP8501_CP_MODE_MASK 0x18 57 #define LP8501_CP_MODE_SHIFT 3 58 #define LP8501_INT_CLK BIT(0) 59 #define LP8501_DEFAULT_CFG (LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE) 60 61 #define LP8501_REG_STATUS 0x3A 62 #define LP8501_ENGINE_BUSY BIT(4) 63 64 #define LP8501_REG_RESET 0x3D 65 #define LP8501_RESET 0xFF 66 67 #define LP8501_REG_PROG_PAGE_SEL 0x4F 68 #define LP8501_PAGE_ENG1 0 69 #define LP8501_PAGE_ENG2 1 70 #define LP8501_PAGE_ENG3 2 71 72 #define LP8501_REG_PROG_MEM 0x50 73 74 #define LP8501_ENG1_IS_LOADING(mode) \ 75 ((mode & LP8501_MODE_ENG1_M) == LP8501_LOAD_ENG1) 76 #define LP8501_ENG2_IS_LOADING(mode) \ 77 ((mode & LP8501_MODE_ENG2_M) == LP8501_LOAD_ENG2) 78 #define LP8501_ENG3_IS_LOADING(mode) \ 79 ((mode & LP8501_MODE_ENG3_M) == LP8501_LOAD_ENG3) 80 81 static inline void lp8501_wait_opmode_done(void) 82 { 83 usleep_range(1000, 2000); 84 } 85 86 static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current) 87 { 88 led->led_current = led_current; 89 lp55xx_write(led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr, 90 led_current); 91 } 92 93 static int lp8501_post_init_device(struct lp55xx_chip *chip) 94 { 95 int ret; 96 u8 val = LP8501_DEFAULT_CFG; 97 98 ret = lp55xx_write(chip, LP8501_REG_ENABLE, LP8501_ENABLE); 99 if (ret) 100 return ret; 101 102 /* Chip startup time is 500 us, 1 - 2 ms gives some margin */ 103 usleep_range(1000, 2000); 104 105 if (chip->pdata->clock_mode != LP55XX_CLOCK_EXT) 106 val |= LP8501_INT_CLK; 107 108 val |= (chip->pdata->charge_pump_mode << LP8501_CP_MODE_SHIFT) & LP8501_CP_MODE_MASK; 109 110 ret = lp55xx_write(chip, LP8501_REG_CONFIG, val); 111 if (ret) 112 return ret; 113 114 /* Power selection for each output */ 115 return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG, 116 LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel); 117 } 118 119 static void lp8501_load_engine(struct lp55xx_chip *chip) 120 { 121 enum lp55xx_engine_index idx = chip->engine_idx; 122 123 static const u8 page_sel[] = { 124 [LP55XX_ENGINE_1] = LP8501_PAGE_ENG1, 125 [LP55XX_ENGINE_2] = LP8501_PAGE_ENG2, 126 [LP55XX_ENGINE_3] = LP8501_PAGE_ENG3, 127 }; 128 129 lp55xx_load_engine(chip); 130 131 lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]); 132 } 133 134 static void lp8501_turn_off_channels(struct lp55xx_chip *chip) 135 { 136 int i; 137 138 for (i = 0; i < LP8501_MAX_LEDS; i++) 139 lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0); 140 } 141 142 static void lp8501_run_engine(struct lp55xx_chip *chip, bool start) 143 { 144 int ret; 145 u8 mode; 146 u8 exec; 147 148 /* stop engine */ 149 if (!start) { 150 lp55xx_stop_all_engine(chip); 151 lp8501_turn_off_channels(chip); 152 return; 153 } 154 155 /* 156 * To run the engine, 157 * operation mode and enable register should updated at the same time 158 */ 159 160 ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode); 161 if (ret) 162 return; 163 164 ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec); 165 if (ret) 166 return; 167 168 /* change operation mode to RUN only when each engine is loading */ 169 if (LP8501_ENG1_IS_LOADING(mode)) { 170 mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1; 171 exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1; 172 } 173 174 if (LP8501_ENG2_IS_LOADING(mode)) { 175 mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2; 176 exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2; 177 } 178 179 if (LP8501_ENG3_IS_LOADING(mode)) { 180 mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3; 181 exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3; 182 } 183 184 lp55xx_write(chip, LP8501_REG_OP_MODE, mode); 185 lp8501_wait_opmode_done(); 186 187 lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec); 188 } 189 190 static int lp8501_update_program_memory(struct lp55xx_chip *chip, 191 const u8 *data, size_t size) 192 { 193 u8 pattern[LP8501_PROGRAM_LENGTH] = {0}; 194 unsigned cmd; 195 char c[3]; 196 int update_size; 197 int nrchars; 198 int offset = 0; 199 int ret; 200 int i; 201 202 /* clear program memory before updating */ 203 for (i = 0; i < LP8501_PROGRAM_LENGTH; i++) 204 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0); 205 206 i = 0; 207 while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) { 208 /* separate sscanfs because length is working only for %s */ 209 ret = sscanf(data + offset, "%2s%n ", c, &nrchars); 210 if (ret != 1) 211 goto err; 212 213 ret = sscanf(c, "%2x", &cmd); 214 if (ret != 1) 215 goto err; 216 217 pattern[i] = (u8)cmd; 218 offset += nrchars; 219 i++; 220 } 221 222 /* Each instruction is 16bit long. Check that length is even */ 223 if (i % 2) 224 goto err; 225 226 update_size = i; 227 for (i = 0; i < update_size; i++) 228 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]); 229 230 return 0; 231 232 err: 233 dev_err(&chip->cl->dev, "wrong pattern format\n"); 234 return -EINVAL; 235 } 236 237 static void lp8501_firmware_loaded(struct lp55xx_chip *chip) 238 { 239 const struct firmware *fw = chip->fw; 240 241 if (fw->size > LP8501_PROGRAM_LENGTH) { 242 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n", 243 fw->size); 244 return; 245 } 246 247 /* 248 * Program memory sequence 249 * 1) set engine mode to "LOAD" 250 * 2) write firmware data into program memory 251 */ 252 253 lp8501_load_engine(chip); 254 lp8501_update_program_memory(chip, fw->data, fw->size); 255 } 256 257 static int lp8501_led_brightness(struct lp55xx_led *led) 258 { 259 struct lp55xx_chip *chip = led->chip; 260 int ret; 261 262 mutex_lock(&chip->lock); 263 ret = lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr, 264 led->brightness); 265 mutex_unlock(&chip->lock); 266 267 return ret; 268 } 269 270 /* Chip specific configurations */ 271 static struct lp55xx_device_config lp8501_cfg = { 272 .reg_op_mode = { 273 .addr = LP8501_REG_OP_MODE, 274 }, 275 .engine_busy = { 276 .addr = LP8501_REG_STATUS, 277 .mask = LP8501_ENGINE_BUSY, 278 }, 279 .reset = { 280 .addr = LP8501_REG_RESET, 281 .val = LP8501_RESET, 282 }, 283 .enable = { 284 .addr = LP8501_REG_ENABLE, 285 .val = LP8501_ENABLE, 286 }, 287 .max_channel = LP8501_MAX_LEDS, 288 .post_init_device = lp8501_post_init_device, 289 .brightness_fn = lp8501_led_brightness, 290 .set_led_current = lp8501_set_led_current, 291 .firmware_cb = lp8501_firmware_loaded, 292 .run_engine = lp8501_run_engine, 293 }; 294 295 static const struct i2c_device_id lp8501_id[] = { 296 { "lp8501", .driver_data = (kernel_ulong_t)&lp8501_cfg, }, 297 { } 298 }; 299 MODULE_DEVICE_TABLE(i2c, lp8501_id); 300 301 static const struct of_device_id of_lp8501_leds_match[] = { 302 { .compatible = "ti,lp8501", .data = &lp8501_cfg, }, 303 {}, 304 }; 305 306 MODULE_DEVICE_TABLE(of, of_lp8501_leds_match); 307 308 static struct i2c_driver lp8501_driver = { 309 .driver = { 310 .name = "lp8501", 311 .of_match_table = of_lp8501_leds_match, 312 }, 313 .probe = lp55xx_probe, 314 .remove = lp55xx_remove, 315 .id_table = lp8501_id, 316 }; 317 318 module_i2c_driver(lp8501_driver); 319 320 MODULE_DESCRIPTION("Texas Instruments LP8501 LED driver"); 321 MODULE_AUTHOR("Milo Kim"); 322 MODULE_LICENSE("GPL"); 323