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 struct an30259a; 59 60 struct an30259a_led { 61 struct an30259a *chip; 62 struct fwnode_handle *fwnode; 63 struct led_classdev cdev; 64 u32 num; 65 enum led_default_state default_state; 66 bool sloping; 67 }; 68 69 struct an30259a { 70 struct mutex mutex; /* held when writing to registers */ 71 struct i2c_client *client; 72 struct an30259a_led leds[AN30259A_MAX_LEDS]; 73 struct regmap *regmap; 74 int num_leds; 75 }; 76 77 static int an30259a_brightness_set(struct led_classdev *cdev, 78 enum led_brightness brightness) 79 { 80 struct an30259a_led *led; 81 int ret; 82 unsigned int led_on; 83 84 led = container_of(cdev, struct an30259a_led, cdev); 85 mutex_lock(&led->chip->mutex); 86 87 ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on); 88 if (ret) 89 goto error; 90 91 switch (brightness) { 92 case LED_OFF: 93 led_on &= ~AN30259A_LED_EN(led->num); 94 led_on &= ~AN30259A_LED_SLOPE(led->num); 95 led->sloping = false; 96 break; 97 default: 98 led_on |= AN30259A_LED_EN(led->num); 99 if (led->sloping) 100 led_on |= AN30259A_LED_SLOPE(led->num); 101 ret = regmap_write(led->chip->regmap, 102 AN30259A_REG_LEDCNT1(led->num), 103 AN30259A_LED_DUTYMAX(0xf) | 104 AN30259A_LED_DUTYMID(0xf)); 105 if (ret) 106 goto error; 107 break; 108 } 109 110 ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on); 111 if (ret) 112 goto error; 113 114 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCC(led->num), 115 brightness); 116 117 error: 118 mutex_unlock(&led->chip->mutex); 119 120 return ret; 121 } 122 123 static int an30259a_blink_set(struct led_classdev *cdev, 124 unsigned long *delay_off, unsigned long *delay_on) 125 { 126 struct an30259a_led *led; 127 int ret, num; 128 unsigned int led_on; 129 unsigned long off = *delay_off, on = *delay_on; 130 131 led = container_of(cdev, struct an30259a_led, cdev); 132 133 mutex_lock(&led->chip->mutex); 134 num = led->num; 135 136 /* slope time can only be a multiple of 500ms. */ 137 if (off % AN30259A_SLOPE_RESOLUTION || on % AN30259A_SLOPE_RESOLUTION) { 138 ret = -EINVAL; 139 goto error; 140 } 141 142 /* up to a maximum of 7500ms. */ 143 if (off > AN30259A_BLINK_MAX_TIME || on > AN30259A_BLINK_MAX_TIME) { 144 ret = -EINVAL; 145 goto error; 146 } 147 148 /* if no blink specified, default to 1 Hz. */ 149 if (!off && !on) { 150 *delay_off = off = 500; 151 *delay_on = on = 500; 152 } 153 154 /* convert into values the HW will understand. */ 155 off /= AN30259A_SLOPE_RESOLUTION; 156 on /= AN30259A_SLOPE_RESOLUTION; 157 158 /* duty min should be zero (=off), delay should be zero. */ 159 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT2(num), 160 AN30259A_LED_DELAY(0) | AN30259A_LED_DUTYMIN(0)); 161 if (ret) 162 goto error; 163 164 /* reset detention time (no "breathing" effect). */ 165 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT3(num), 166 AN30259A_LED_DT1(0) | AN30259A_LED_DT2(0)); 167 if (ret) 168 goto error; 169 ret = regmap_write(led->chip->regmap, AN30259A_REG_LEDCNT4(num), 170 AN30259A_LED_DT3(0) | AN30259A_LED_DT4(0)); 171 if (ret) 172 goto error; 173 174 /* slope time controls on/off cycle length. */ 175 ret = regmap_write(led->chip->regmap, AN30259A_REG_SLOPE(num), 176 AN30259A_LED_SLOPETIME1(off) | 177 AN30259A_LED_SLOPETIME2(on)); 178 if (ret) 179 goto error; 180 181 /* Finally, enable slope mode. */ 182 ret = regmap_read(led->chip->regmap, AN30259A_REG_LED_ON, &led_on); 183 if (ret) 184 goto error; 185 186 led_on |= AN30259A_LED_SLOPE(num) | AN30259A_LED_EN(led->num); 187 188 ret = regmap_write(led->chip->regmap, AN30259A_REG_LED_ON, led_on); 189 190 if (!ret) 191 led->sloping = true; 192 error: 193 mutex_unlock(&led->chip->mutex); 194 195 return ret; 196 } 197 198 static int an30259a_dt_init(struct i2c_client *client, 199 struct an30259a *chip) 200 { 201 struct device_node *np = dev_of_node(&client->dev), *child; 202 int count, ret; 203 int i = 0; 204 struct an30259a_led *led; 205 206 count = of_get_available_child_count(np); 207 if (!count || count > AN30259A_MAX_LEDS) 208 return -EINVAL; 209 210 for_each_available_child_of_node(np, child) { 211 u32 source; 212 213 ret = of_property_read_u32(child, "reg", &source); 214 if (ret != 0 || !source || source > AN30259A_MAX_LEDS) { 215 dev_err(&client->dev, "Couldn't read LED address: %d\n", 216 ret); 217 count--; 218 continue; 219 } 220 221 led = &chip->leds[i]; 222 223 led->num = source; 224 led->chip = chip; 225 led->fwnode = of_fwnode_handle(child); 226 led->default_state = led_init_default_state_get(led->fwnode); 227 228 i++; 229 } 230 231 if (!count) 232 return -EINVAL; 233 234 chip->num_leds = i; 235 236 return 0; 237 } 238 239 static const struct regmap_config an30259a_regmap_config = { 240 .reg_bits = 8, 241 .val_bits = 8, 242 .max_register = AN30259A_REG_MAX, 243 }; 244 245 static void an30259a_init_default_state(struct an30259a_led *led) 246 { 247 struct an30259a *chip = led->chip; 248 int led_on, err; 249 250 switch (led->default_state) { 251 case LEDS_DEFSTATE_ON: 252 led->cdev.brightness = LED_FULL; 253 break; 254 case LEDS_DEFSTATE_KEEP: 255 err = regmap_read(chip->regmap, AN30259A_REG_LED_ON, &led_on); 256 if (err) 257 break; 258 259 if (!(led_on & AN30259A_LED_EN(led->num))) { 260 led->cdev.brightness = LED_OFF; 261 break; 262 } 263 regmap_read(chip->regmap, AN30259A_REG_LEDCC(led->num), 264 &led->cdev.brightness); 265 break; 266 default: 267 led->cdev.brightness = LED_OFF; 268 } 269 270 an30259a_brightness_set(&led->cdev, led->cdev.brightness); 271 } 272 273 static int an30259a_probe(struct i2c_client *client) 274 { 275 struct an30259a *chip; 276 int i, err; 277 278 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 279 if (!chip) 280 return -ENOMEM; 281 282 err = an30259a_dt_init(client, chip); 283 if (err < 0) 284 return err; 285 286 err = devm_mutex_init(&client->dev, &chip->mutex); 287 if (err) 288 return err; 289 290 chip->client = client; 291 i2c_set_clientdata(client, chip); 292 293 chip->regmap = devm_regmap_init_i2c(client, &an30259a_regmap_config); 294 295 if (IS_ERR(chip->regmap)) { 296 err = PTR_ERR(chip->regmap); 297 dev_err(&client->dev, "Failed to allocate register map: %d\n", 298 err); 299 goto exit; 300 } 301 302 for (i = 0; i < chip->num_leds; i++) { 303 struct led_init_data init_data = {}; 304 305 an30259a_init_default_state(&chip->leds[i]); 306 chip->leds[i].cdev.brightness_set_blocking = 307 an30259a_brightness_set; 308 chip->leds[i].cdev.blink_set = an30259a_blink_set; 309 310 init_data.fwnode = chip->leds[i].fwnode; 311 init_data.devicename = AN30259A_NAME; 312 init_data.default_label = ":"; 313 314 err = devm_led_classdev_register_ext(&client->dev, 315 &chip->leds[i].cdev, 316 &init_data); 317 if (err < 0) 318 goto exit; 319 } 320 return 0; 321 322 exit: 323 return err; 324 } 325 326 static const struct of_device_id an30259a_match_table[] = { 327 { .compatible = "panasonic,an30259a", }, 328 { /* sentinel */ }, 329 }; 330 331 MODULE_DEVICE_TABLE(of, an30259a_match_table); 332 333 static const struct i2c_device_id an30259a_id[] = { 334 { "an30259a", 0 }, 335 { /* sentinel */ }, 336 }; 337 MODULE_DEVICE_TABLE(i2c, an30259a_id); 338 339 static struct i2c_driver an30259a_driver = { 340 .driver = { 341 .name = "leds-an30259a", 342 .of_match_table = an30259a_match_table, 343 }, 344 .probe = an30259a_probe, 345 .id_table = an30259a_id, 346 }; 347 348 module_i2c_driver(an30259a_driver); 349 350 MODULE_AUTHOR("Simon Shields <simon@lineageos.org>"); 351 MODULE_DESCRIPTION("AN30259A LED driver"); 352 MODULE_LICENSE("GPL v2"); 353