1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2015-16 Golden Delicious Computers 4 * 5 * Author: Nikolaus Schaller <hns@goldelico.com> 6 * 7 * LED driver for the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light 8 * effect LEDs. 9 */ 10 11 #include <linux/err.h> 12 #include <linux/i2c.h> 13 #include <linux/leds.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include <linux/of_device.h> 17 #include <linux/regmap.h> 18 #include <linux/slab.h> 19 #include <linux/delay.h> 20 #include <linux/gpio/consumer.h> 21 22 /* register numbers */ 23 #define IS31FL319X_SHUTDOWN 0x00 24 #define IS31FL319X_CTRL1 0x01 25 #define IS31FL319X_CTRL2 0x02 26 #define IS31FL319X_CONFIG1 0x03 27 #define IS31FL319X_CONFIG2 0x04 28 #define IS31FL319X_RAMP_MODE 0x05 29 #define IS31FL319X_BREATH_MASK 0x06 30 #define IS31FL319X_PWM(channel) (0x07 + channel) 31 #define IS31FL319X_DATA_UPDATE 0x10 32 #define IS31FL319X_T0(channel) (0x11 + channel) 33 #define IS31FL319X_T123_1 0x1a 34 #define IS31FL319X_T123_2 0x1b 35 #define IS31FL319X_T123_3 0x1c 36 #define IS31FL319X_T4(channel) (0x1d + channel) 37 #define IS31FL319X_TIME_UPDATE 0x26 38 #define IS31FL319X_RESET 0xff 39 40 #define IS31FL319X_REG_CNT (IS31FL319X_RESET + 1) 41 42 #define IS31FL319X_MAX_LEDS 9 43 44 /* CS (Current Setting) in CONFIG2 register */ 45 #define IS31FL319X_CONFIG2_CS_SHIFT 4 46 #define IS31FL319X_CONFIG2_CS_MASK 0x7 47 #define IS31FL319X_CONFIG2_CS_STEP_REF 12 48 49 #define IS31FL319X_CURRENT_MIN ((u32)5000) 50 #define IS31FL319X_CURRENT_MAX ((u32)40000) 51 #define IS31FL319X_CURRENT_STEP ((u32)5000) 52 #define IS31FL319X_CURRENT_DEFAULT ((u32)20000) 53 54 /* Audio gain in CONFIG2 register */ 55 #define IS31FL319X_AUDIO_GAIN_DB_MAX ((u32)21) 56 #define IS31FL319X_AUDIO_GAIN_DB_STEP ((u32)3) 57 58 /* 59 * regmap is used as a cache of chip's register space, 60 * to avoid reading back brightness values from chip, 61 * which is known to hang. 62 */ 63 struct is31fl319x_chip { 64 const struct is31fl319x_chipdef *cdef; 65 struct i2c_client *client; 66 struct gpio_desc *shutdown_gpio; 67 struct regmap *regmap; 68 struct mutex lock; 69 u32 audio_gain_db; 70 71 struct is31fl319x_led { 72 struct is31fl319x_chip *chip; 73 struct led_classdev cdev; 74 u32 max_microamp; 75 bool configured; 76 } leds[IS31FL319X_MAX_LEDS]; 77 }; 78 79 struct is31fl319x_chipdef { 80 int num_leds; 81 }; 82 83 static const struct is31fl319x_chipdef is31fl3190_cdef = { 84 .num_leds = 1, 85 }; 86 87 static const struct is31fl319x_chipdef is31fl3193_cdef = { 88 .num_leds = 3, 89 }; 90 91 static const struct is31fl319x_chipdef is31fl3196_cdef = { 92 .num_leds = 6, 93 }; 94 95 static const struct is31fl319x_chipdef is31fl3199_cdef = { 96 .num_leds = 9, 97 }; 98 99 static const struct of_device_id of_is31fl319x_match[] = { 100 { .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, }, 101 { .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, }, 102 { .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, }, 103 { .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, }, 104 { .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, }, 105 { .compatible = "si-en,sn3199", .data = &is31fl3199_cdef, }, 106 { } 107 }; 108 MODULE_DEVICE_TABLE(of, of_is31fl319x_match); 109 110 static int is31fl319x_brightness_set(struct led_classdev *cdev, 111 enum led_brightness brightness) 112 { 113 struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led, 114 cdev); 115 struct is31fl319x_chip *is31 = led->chip; 116 int chan = led - is31->leds; 117 int ret; 118 int i; 119 u8 ctrl1 = 0, ctrl2 = 0; 120 121 dev_dbg(&is31->client->dev, "%s %d: %d\n", __func__, chan, brightness); 122 123 mutex_lock(&is31->lock); 124 125 /* update PWM register */ 126 ret = regmap_write(is31->regmap, IS31FL319X_PWM(chan), brightness); 127 if (ret < 0) 128 goto out; 129 130 /* read current brightness of all PWM channels */ 131 for (i = 0; i < is31->cdef->num_leds; i++) { 132 unsigned int pwm_value; 133 bool on; 134 135 /* 136 * since neither cdev nor the chip can provide 137 * the current setting, we read from the regmap cache 138 */ 139 140 ret = regmap_read(is31->regmap, IS31FL319X_PWM(i), &pwm_value); 141 dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n", 142 __func__, i, ret, pwm_value); 143 on = ret >= 0 && pwm_value > LED_OFF; 144 145 if (i < 3) 146 ctrl1 |= on << i; /* 0..2 => bit 0..2 */ 147 else if (i < 6) 148 ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */ 149 else 150 ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */ 151 } 152 153 if (ctrl1 > 0 || ctrl2 > 0) { 154 dev_dbg(&is31->client->dev, "power up %02x %02x\n", 155 ctrl1, ctrl2); 156 regmap_write(is31->regmap, IS31FL319X_CTRL1, ctrl1); 157 regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2); 158 /* update PWMs */ 159 regmap_write(is31->regmap, IS31FL319X_DATA_UPDATE, 0x00); 160 /* enable chip from shut down */ 161 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01); 162 } else { 163 dev_dbg(&is31->client->dev, "power down\n"); 164 /* shut down (no need to clear CTRL1/2) */ 165 ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00); 166 } 167 168 out: 169 mutex_unlock(&is31->lock); 170 171 return ret; 172 } 173 174 static int is31fl319x_parse_child_dt(const struct device *dev, 175 const struct device_node *child, 176 struct is31fl319x_led *led) 177 { 178 struct led_classdev *cdev = &led->cdev; 179 int ret; 180 181 if (of_property_read_string(child, "label", &cdev->name)) 182 cdev->name = child->name; 183 184 ret = of_property_read_string(child, "linux,default-trigger", 185 &cdev->default_trigger); 186 if (ret < 0 && ret != -EINVAL) /* is optional */ 187 return ret; 188 189 led->max_microamp = IS31FL319X_CURRENT_DEFAULT; 190 ret = of_property_read_u32(child, "led-max-microamp", 191 &led->max_microamp); 192 if (!ret) { 193 if (led->max_microamp < IS31FL319X_CURRENT_MIN) 194 return -EINVAL; /* not supported */ 195 led->max_microamp = min(led->max_microamp, 196 IS31FL319X_CURRENT_MAX); 197 } 198 199 return 0; 200 } 201 202 static int is31fl319x_parse_dt(struct device *dev, 203 struct is31fl319x_chip *is31) 204 { 205 struct device_node *np = dev_of_node(dev), *child; 206 int count; 207 int ret; 208 209 if (!np) 210 return -ENODEV; 211 212 is31->shutdown_gpio = devm_gpiod_get_optional(dev, 213 "shutdown", 214 GPIOD_OUT_HIGH); 215 if (IS_ERR(is31->shutdown_gpio)) { 216 ret = PTR_ERR(is31->shutdown_gpio); 217 dev_err(dev, "Failed to get shutdown gpio: %d\n", ret); 218 return ret; 219 } 220 221 is31->cdef = device_get_match_data(dev); 222 223 count = of_get_available_child_count(np); 224 225 dev_dbg(dev, "probing with %d leds defined in DT\n", count); 226 227 if (!count || count > is31->cdef->num_leds) { 228 dev_err(dev, "Number of leds defined must be between 1 and %u\n", 229 is31->cdef->num_leds); 230 return -ENODEV; 231 } 232 233 for_each_available_child_of_node(np, child) { 234 struct is31fl319x_led *led; 235 u32 reg; 236 237 ret = of_property_read_u32(child, "reg", ®); 238 if (ret) { 239 dev_err(dev, "Failed to read led 'reg' property\n"); 240 goto put_child_node; 241 } 242 243 if (reg < 1 || reg > is31->cdef->num_leds) { 244 dev_err(dev, "invalid led reg %u\n", reg); 245 ret = -EINVAL; 246 goto put_child_node; 247 } 248 249 led = &is31->leds[reg - 1]; 250 251 if (led->configured) { 252 dev_err(dev, "led %u is already configured\n", reg); 253 ret = -EINVAL; 254 goto put_child_node; 255 } 256 257 ret = is31fl319x_parse_child_dt(dev, child, led); 258 if (ret) { 259 dev_err(dev, "led %u DT parsing failed\n", reg); 260 goto put_child_node; 261 } 262 263 led->configured = true; 264 } 265 266 is31->audio_gain_db = 0; 267 ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db); 268 if (!ret) 269 is31->audio_gain_db = min(is31->audio_gain_db, 270 IS31FL319X_AUDIO_GAIN_DB_MAX); 271 272 return 0; 273 274 put_child_node: 275 of_node_put(child); 276 return ret; 277 } 278 279 static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg) 280 { /* we have no readable registers */ 281 return false; 282 } 283 284 static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg) 285 { /* volatile registers are not cached */ 286 switch (reg) { 287 case IS31FL319X_DATA_UPDATE: 288 case IS31FL319X_TIME_UPDATE: 289 case IS31FL319X_RESET: 290 return true; /* always write-through */ 291 default: 292 return false; 293 } 294 } 295 296 static const struct reg_default is31fl319x_reg_defaults[] = { 297 { IS31FL319X_CONFIG1, 0x00}, 298 { IS31FL319X_CONFIG2, 0x00}, 299 { IS31FL319X_PWM(0), 0x00}, 300 { IS31FL319X_PWM(1), 0x00}, 301 { IS31FL319X_PWM(2), 0x00}, 302 { IS31FL319X_PWM(3), 0x00}, 303 { IS31FL319X_PWM(4), 0x00}, 304 { IS31FL319X_PWM(5), 0x00}, 305 { IS31FL319X_PWM(6), 0x00}, 306 { IS31FL319X_PWM(7), 0x00}, 307 { IS31FL319X_PWM(8), 0x00}, 308 }; 309 310 static struct regmap_config regmap_config = { 311 .reg_bits = 8, 312 .val_bits = 8, 313 .max_register = IS31FL319X_REG_CNT, 314 .cache_type = REGCACHE_FLAT, 315 .readable_reg = is31fl319x_readable_reg, 316 .volatile_reg = is31fl319x_volatile_reg, 317 .reg_defaults = is31fl319x_reg_defaults, 318 .num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults), 319 }; 320 321 static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp) 322 { /* round down to nearest supported value (range check done by caller) */ 323 u32 step = microamp / IS31FL319X_CURRENT_STEP; 324 325 return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) & 326 IS31FL319X_CONFIG2_CS_MASK) << 327 IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */ 328 } 329 330 static inline int is31fl319x_db_to_gain(u32 dezibel) 331 { /* round down to nearest supported value (range check done by caller) */ 332 return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP; 333 } 334 335 static int is31fl319x_probe(struct i2c_client *client, 336 const struct i2c_device_id *id) 337 { 338 struct is31fl319x_chip *is31; 339 struct device *dev = &client->dev; 340 int err; 341 int i = 0; 342 u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX; 343 344 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 345 return -EIO; 346 347 is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL); 348 if (!is31) 349 return -ENOMEM; 350 351 mutex_init(&is31->lock); 352 353 err = is31fl319x_parse_dt(&client->dev, is31); 354 if (err) 355 goto free_mutex; 356 357 if (is31->shutdown_gpio) { 358 gpiod_direction_output(is31->shutdown_gpio, 0); 359 mdelay(5); 360 gpiod_direction_output(is31->shutdown_gpio, 1); 361 } 362 363 is31->client = client; 364 is31->regmap = devm_regmap_init_i2c(client, ®map_config); 365 if (IS_ERR(is31->regmap)) { 366 dev_err(&client->dev, "failed to allocate register map\n"); 367 err = PTR_ERR(is31->regmap); 368 goto free_mutex; 369 } 370 371 i2c_set_clientdata(client, is31); 372 373 /* check for write-reply from chip (we can't read any registers) */ 374 err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00); 375 if (err < 0) { 376 dev_err(&client->dev, "no response from chip write: err = %d\n", 377 err); 378 err = -EIO; /* does not answer */ 379 goto free_mutex; 380 } 381 382 /* 383 * Kernel conventions require per-LED led-max-microamp property. 384 * But the chip does not allow to limit individual LEDs. 385 * So we take minimum from all subnodes for safety of hardware. 386 */ 387 for (i = 0; i < is31->cdef->num_leds; i++) 388 if (is31->leds[i].configured && 389 is31->leds[i].max_microamp < aggregated_led_microamp) 390 aggregated_led_microamp = is31->leds[i].max_microamp; 391 392 regmap_write(is31->regmap, IS31FL319X_CONFIG2, 393 is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) | 394 is31fl319x_db_to_gain(is31->audio_gain_db)); 395 396 for (i = 0; i < is31->cdef->num_leds; i++) { 397 struct is31fl319x_led *led = &is31->leds[i]; 398 399 if (!led->configured) 400 continue; 401 402 led->chip = is31; 403 led->cdev.brightness_set_blocking = is31fl319x_brightness_set; 404 405 err = devm_led_classdev_register(&client->dev, &led->cdev); 406 if (err < 0) 407 goto free_mutex; 408 } 409 410 return 0; 411 412 free_mutex: 413 mutex_destroy(&is31->lock); 414 return err; 415 } 416 417 static int is31fl319x_remove(struct i2c_client *client) 418 { 419 struct is31fl319x_chip *is31 = i2c_get_clientdata(client); 420 421 mutex_destroy(&is31->lock); 422 return 0; 423 } 424 425 /* 426 * i2c-core (and modalias) requires that id_table be properly filled, 427 * even though it is not used for DeviceTree based instantiation. 428 */ 429 static const struct i2c_device_id is31fl319x_id[] = { 430 { "is31fl3190" }, 431 { "is31fl3191" }, 432 { "is31fl3193" }, 433 { "is31fl3196" }, 434 { "is31fl3199" }, 435 { "sn3199" }, 436 {}, 437 }; 438 MODULE_DEVICE_TABLE(i2c, is31fl319x_id); 439 440 static struct i2c_driver is31fl319x_driver = { 441 .driver = { 442 .name = "leds-is31fl319x", 443 .of_match_table = of_match_ptr(of_is31fl319x_match), 444 }, 445 .probe = is31fl319x_probe, 446 .remove = is31fl319x_remove, 447 .id_table = is31fl319x_id, 448 }; 449 450 module_i2c_driver(is31fl319x_driver); 451 452 MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>"); 453 MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>"); 454 MODULE_DESCRIPTION("IS31FL319X LED driver"); 455 MODULE_LICENSE("GPL v2"); 456