1 // SPDX-License-Identifier: GPL-2.0+ 2 // 3 // Driver for Panasonic AN30259A 3-channel LED driver 4 // 5 // Copyright (c) 2018 Simon Shields <simon@lineageos.org> 6 // 7 // Datasheet: 8 // https://www.alliedelec.com/m/d/a9d2b3ee87c2d1a535a41dd747b1c247.pdf 9 10 #include <linux/i2c.h> 11 #include <linux/leds.h> 12 #include <linux/module.h> 13 #include <linux/mutex.h> 14 #include <linux/of.h> 15 #include <linux/regmap.h> 16 17 #define AN30259A_MAX_LEDS 3 18 19 #define AN30259A_REG_SRESET 0x00 20 #define AN30259A_LED_SRESET BIT(0) 21 22 /* LED power registers */ 23 #define AN30259A_REG_LED_ON 0x01 24 #define AN30259A_LED_EN(x) BIT((x) - 1) 25 #define AN30259A_LED_SLOPE(x) BIT(((x) - 1) + 4) 26 27 #define AN30259A_REG_LEDCC(x) (0x03 + ((x) - 1)) 28 29 /* slope control registers */ 30 #define AN30259A_REG_SLOPE(x) (0x06 + ((x) - 1)) 31 #define AN30259A_LED_SLOPETIME1(x) (x) 32 #define AN30259A_LED_SLOPETIME2(x) ((x) << 4) 33 34 #define AN30259A_REG_LEDCNT1(x) (0x09 + (4 * ((x) - 1))) 35 #define AN30259A_LED_DUTYMAX(x) ((x) << 4) 36 #define AN30259A_LED_DUTYMID(x) (x) 37 38 #define AN30259A_REG_LEDCNT2(x) (0x0A + (4 * ((x) - 1))) 39 #define AN30259A_LED_DELAY(x) ((x) << 4) 40 #define AN30259A_LED_DUTYMIN(x) (x) 41 42 /* detention time control (length of each slope step) */ 43 #define AN30259A_REG_LEDCNT3(x) (0x0B + (4 * ((x) - 1))) 44 #define AN30259A_LED_DT1(x) (x) 45 #define AN30259A_LED_DT2(x) ((x) << 4) 46 47 #define AN30259A_REG_LEDCNT4(x) (0x0C + (4 * ((x) - 1))) 48 #define AN30259A_LED_DT3(x) (x) 49 #define AN30259A_LED_DT4(x) ((x) << 4) 50 51 #define AN30259A_REG_MAX 0x14 52 53 #define AN30259A_BLINK_MAX_TIME 7500 /* ms */ 54 #define AN30259A_SLOPE_RESOLUTION 500 /* ms */ 55 56 #define AN30259A_NAME "an30259a" 57 58 #define STATE_OFF 0 59 #define STATE_KEEP 1 60 #define STATE_ON 2 61 62 struct an30259a; 63 64 struct an30259a_led { 65 struct an30259a *chip; 66 struct fwnode_handle *fwnode; 67 struct led_classdev cdev; 68 u32 num; 69 u32 default_state; 70 bool sloping; 71 }; 72 73 struct an30259a { 74 struct mutex mutex; /* held when writing to registers */ 75 struct i2c_client *client; 76 struct an30259a_led leds[AN30259A_MAX_LEDS]; 77 struct regmap *regmap; 78 int num_leds; 79 }; 80 81 static int an30259a_brightness_set(struct led_classdev *cdev, 82 enum led_brightness brightness) 83 { 84 struct an30259a_led *led; 85 int ret; 86 unsigned int led_on; 87 88 led = container_of(cdev, struct an30259a_led, cdev); 89 mutex_lock(&led->chip->mutex); 90 91 ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on); 92 if (ret) 93 goto error; 94 95 switch (brightness) { 96 case LED_OFF: 97 led_on &= ~AN30259A_LED_EN(led->num); 98 led_on &= ~AN30259A_LED_SLOPE(led->num); 99 led->sloping = false; 100 break; 101 default: 102 led_on |= AN30259A_LED_EN(led->num); 103 if (led->sloping) 104 led_on |= AN30259A_LED_SLOPE(led->num); 105 ret = regmap_write(led->chip->regmap, 106 AN30259A_REG_LEDCNT1(led->num), 107 AN30259A_LED_DUTYMAX(0xf) | 108 AN30259A_LED_DUTYMID(0xf)); 109 if (ret) 110 goto error; 111 break; 112 } 113 114 ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on); 115 if (ret) 116 goto error; 117 118 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCC(led->num), 119 brightness); 120 121 error: 122 mutex_unlock(&led->chip->mutex); 123 124 return ret; 125 } 126 127 static int an30259a_blink_set(struct led_classdev *cdev, 128 unsigned long *delay_off, unsigned long *delay_on) 129 { 130 struct an30259a_led *led; 131 int ret, num; 132 unsigned int led_on; 133 unsigned long off = *delay_off, on = *delay_on; 134 135 led = container_of(cdev, struct an30259a_led, cdev); 136 137 mutex_lock(&led->chip->mutex); 138 num = led->num; 139 140 /* slope time can only be a multiple of 500ms. */ 141 if (off % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) { 142 ret = -EINVAL; 143 goto error; 144 } 145 146 /* up to a maximum of 7500ms. */ 147 if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_BLINK_MAX_TIME) { 148 ret = -EINVAL; 149 goto error; 150 } 151 152 /* if no blink specified, default to 1 Hz. */ 153 if (!off && !on) { 154 *delay_off = off = 500; 155 *delay_on = on = 500; 156 } 157 158 /* convert into values the HW will understand. */ 159 off /= AN30259A_SLOPE_RESOLUTION; 160 on /= AN30259A_SLOPE_RESOLUTION; 161 162 /* duty min should be zero (=off), delay should be zero. */ 163 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num), 164 AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0)); 165 if (ret) 166 goto error; 167 168 /* reset detention time (no "breathing" effect). */ 169 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num), 170 AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0)); 171 if (ret) 172 goto error; 173 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num), 174 AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0)); 175 if (ret) 176 goto error; 177 178 /* slope time controls on/off cycle length. */ 179 ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num), 180 AN30259A_LED_SLOPETIME1(off) | 181 AN30259A_LED_SLOPETIME2(on)); 182 if (ret) 183 goto error; 184 185 /* Finally, enable slope mode. */ 186 ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on); 187 if (ret) 188 goto error; 189 190 led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num); 191 192 ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on); 193 194 if (!ret) 195 led->sloping = true; 196 error: 197 mutex_unlock(&led->chip->mutex); 198 199 return ret; 200 } 201 202 static int an30259a_dt_init(struct i2c_client *client, 203 struct an30259a *chip) 204 { 205 struct device_node *np = client->dev.of_node, *child; 206 int count, ret; 207 int i = 0; 208 const char *str; 209 struct an30259a_led *led; 210 211 count = of_get_child_count(np); 212 if (!count || count > AN30259A_MAX_LEDS) 213 return -EINVAL; 214 215 for_each_available_child_of_node(np, child) { 216 u32 source; 217 218 ret = of_property_read_u32(child, "reg", &source); 219 if (ret != 0 || !source || source > AN30259A_MAX_LEDS) { 220 dev_err(&client->dev, "Couldn't read LED address: %d\n", 221 ret); 222 count--; 223 continue; 224 } 225 226 led = &chip->leds[i]; 227 228 led->num = source; 229 led->chip = chip; 230 led->fwnode = of_fwnode_handle(child); 231 232 if (!of_property_read_string(child, "default-state", &str)) { 233 if (!strcmp(str, "on")) 234 led->default_state = STATE_ON; 235 else if (!strcmp(str, "keep")) 236 led->default_state = STATE_KEEP; 237 else 238 led->default_state = STATE_OFF; 239 } 240 241 of_property_read_string(child, "linux,default-trigger", 242 &led->cdev.default_trigger); 243 244 i++; 245 } 246 247 if (!count) 248 return -EINVAL; 249 250 chip->num_leds = i; 251 252 return 0; 253 } 254 255 static const struct regmap_config an30259a_regmap_config = { 256 .reg_bits = 8, 257 .val_bits = 8, 258 .max_register = AN30259A_REG_MAX, 259 }; 260 261 static void an30259a_init_default_state(struct an30259a_led *led) 262 { 263 struct an30259a *chip = led->chip; 264 int led_on, err; 265 266 switch (led->default_state) { 267 case STATE_ON: 268 led->cdev.brightness = LED_FULL; 269 break; 270 case STATE_KEEP: 271 err = regmap_read(chip->regmap, AN30259A_REG_LED_ON, &led_on); 272 if (err) 273 break; 274 275 if (!(led_on & AN30259A_LED_EN(led->num))) { 276 led->cdev.brightness = LED_OFF; 277 break; 278 } 279 regmap_read(chip->regmap, AN30259A_REG_LEDCC(led->num), 280 &led->cdev.brightness); 281 break; 282 default: 283 led->cdev.brightness = LED_OFF; 284 } 285 286 an30259a_brightness_set(&led->cdev, led->cdev.brightness); 287 } 288 289 static int an30259a_probe(struct i2c_client *client) 290 { 291 struct an30259a *chip; 292 int i, err; 293 294 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 295 if (!chip) 296 return -ENOMEM; 297 298 err = an30259a_dt_init(client, chip); 299 if (err < 0) 300 return err; 301 302 mutex_init(&chip->mutex); 303 chip->client = client; 304 i2c_set_clientdata(client, chip); 305 306 chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config); 307 308 for (i = 0; i < chip->num_leds; i++) { 309 struct led_init_data init_data = {}; 310 311 an30259a_init_default_state(&chip->leds[i]); 312 chip->leds[i].cdev.brightness_set_blocking = 313 an30259a_brightness_set; 314 chip->leds[i].cdev.blink_set = an30259a_blink_set; 315 316 init_data.fwnode = chip->leds[i].fwnode; 317 init_data.devicename = AN30259A_NAME; 318 init_data.default_label = ":"; 319 320 err = devm_led_classdev_register_ext(&client->dev, 321 &chip->leds[i].cdev, 322 &init_data); 323 if (err < 0) 324 goto exit; 325 } 326 return 0; 327 328 exit: 329 mutex_destroy(&chip->mutex); 330 return err; 331 } 332 333 static int an30259a_remove(struct i2c_client *client) 334 { 335 struct an30259a *chip = i2c_get_clientdata(client); 336 337 mutex_destroy(&chip->mutex); 338 339 return 0; 340 } 341 342 static const struct of_device_id an30259a_match_table[] = { 343 { .compatible = "panasonic,an30259a", }, 344 { /* sentinel */ }, 345 }; 346 347 MODULE_DEVICE_TABLE(of, an30259a_match_table); 348 349 static const struct i2c_device_id an30259a_id[] = { 350 { "an30259a", 0 }, 351 { /* sentinel */ }, 352 }; 353 MODULE_DEVICE_TABLE(i2c, an30259a_id); 354 355 static struct i2c_driver an30259a_driver = { 356 .driver = { 357 .name = "leds-an30259a", 358 .of_match_table = of_match_ptr(an30259a_match_table), 359 }, 360 .probe_new = an30259a_probe, 361 .remove = an30259a_remove, 362 .id_table = an30259a_id, 363 }; 364 365 module_i2c_driver(an30259a_driver); 366 367 MODULE_AUTHOR("Simon Shields <simon@lineageos.org>"); 368 MODULE_DESCRIPTION("AN30259A LED driver"); 369 MODULE_LICENSE("GPL v2"); 370