1 // SPDX-License-Identifier: GPL-2.0 2 // TI LM3697 LED chip family driver 3 // Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/ 4 5 #include <linux/gpio/consumer.h> 6 #include <linux/i2c.h> 7 #include <linux/of.h> 8 #include <linux/of_gpio.h> 9 #include <linux/regulator/consumer.h> 10 #include <linux/leds-ti-lmu-common.h> 11 12 #define LM3697_REV 0x0 13 #define LM3697_RESET 0x1 14 #define LM3697_OUTPUT_CONFIG 0x10 15 #define LM3697_CTRL_A_RAMP 0x11 16 #define LM3697_CTRL_B_RAMP 0x12 17 #define LM3697_CTRL_A_B_RT_RAMP 0x13 18 #define LM3697_CTRL_A_B_RAMP_CFG 0x14 19 #define LM3697_CTRL_A_B_BRT_CFG 0x16 20 #define LM3697_CTRL_A_FS_CURR_CFG 0x17 21 #define LM3697_CTRL_B_FS_CURR_CFG 0x18 22 #define LM3697_PWM_CFG 0x1c 23 #define LM3697_CTRL_A_BRT_LSB 0x20 24 #define LM3697_CTRL_A_BRT_MSB 0x21 25 #define LM3697_CTRL_B_BRT_LSB 0x22 26 #define LM3697_CTRL_B_BRT_MSB 0x23 27 #define LM3697_CTRL_ENABLE 0x24 28 29 #define LM3697_SW_RESET BIT(0) 30 31 #define LM3697_CTRL_A_EN BIT(0) 32 #define LM3697_CTRL_B_EN BIT(1) 33 #define LM3697_CTRL_A_B_EN (LM3697_CTRL_A_EN | LM3697_CTRL_B_EN) 34 35 #define LM3697_MAX_LED_STRINGS 3 36 37 #define LM3697_CONTROL_A 0 38 #define LM3697_CONTROL_B 1 39 #define LM3697_MAX_CONTROL_BANKS 2 40 41 /** 42 * struct lm3697_led - 43 * @hvled_strings: Array of LED strings associated with a control bank 44 * @label: LED label 45 * @led_dev: LED class device 46 * @priv: Pointer to the device struct 47 * @lmu_data: Register and setting values for common code 48 * @control_bank: Control bank the LED is associated to. 0 is control bank A 49 * 1 is control bank B 50 */ 51 struct lm3697_led { 52 u32 hvled_strings[LM3697_MAX_LED_STRINGS]; 53 char label[LED_MAX_NAME_SIZE]; 54 struct led_classdev led_dev; 55 struct lm3697 *priv; 56 struct ti_lmu_bank lmu_data; 57 int control_bank; 58 int enabled; 59 int num_leds; 60 }; 61 62 /** 63 * struct lm3697 - 64 * @enable_gpio: Hardware enable gpio 65 * @regulator: LED supply regulator pointer 66 * @client: Pointer to the I2C client 67 * @regmap: Devices register map 68 * @dev: Pointer to the devices device struct 69 * @lock: Lock for reading/writing the device 70 * @leds: Array of LED strings 71 */ 72 struct lm3697 { 73 struct gpio_desc *enable_gpio; 74 struct regulator *regulator; 75 struct i2c_client *client; 76 struct regmap *regmap; 77 struct device *dev; 78 struct mutex lock; 79 80 int bank_cfg; 81 int num_banks; 82 83 struct lm3697_led leds[]; 84 }; 85 86 static const struct reg_default lm3697_reg_defs[] = { 87 {LM3697_OUTPUT_CONFIG, 0x6}, 88 {LM3697_CTRL_A_RAMP, 0x0}, 89 {LM3697_CTRL_B_RAMP, 0x0}, 90 {LM3697_CTRL_A_B_RT_RAMP, 0x0}, 91 {LM3697_CTRL_A_B_RAMP_CFG, 0x0}, 92 {LM3697_CTRL_A_B_BRT_CFG, 0x0}, 93 {LM3697_CTRL_A_FS_CURR_CFG, 0x13}, 94 {LM3697_CTRL_B_FS_CURR_CFG, 0x13}, 95 {LM3697_PWM_CFG, 0xc}, 96 {LM3697_CTRL_A_BRT_LSB, 0x0}, 97 {LM3697_CTRL_A_BRT_MSB, 0x0}, 98 {LM3697_CTRL_B_BRT_LSB, 0x0}, 99 {LM3697_CTRL_B_BRT_MSB, 0x0}, 100 {LM3697_CTRL_ENABLE, 0x0}, 101 }; 102 103 static const struct regmap_config lm3697_regmap_config = { 104 .reg_bits = 8, 105 .val_bits = 8, 106 107 .max_register = LM3697_CTRL_ENABLE, 108 .reg_defaults = lm3697_reg_defs, 109 .num_reg_defaults = ARRAY_SIZE(lm3697_reg_defs), 110 .cache_type = REGCACHE_FLAT, 111 }; 112 113 static int lm3697_brightness_set(struct led_classdev *led_cdev, 114 enum led_brightness brt_val) 115 { 116 struct lm3697_led *led = container_of(led_cdev, struct lm3697_led, 117 led_dev); 118 int ctrl_en_val = (1 << led->control_bank); 119 struct device *dev = led->priv->dev; 120 int ret; 121 122 mutex_lock(&led->priv->lock); 123 124 if (brt_val == LED_OFF) { 125 ret = regmap_update_bits(led->priv->regmap, LM3697_CTRL_ENABLE, 126 ctrl_en_val, ~ctrl_en_val); 127 if (ret) { 128 dev_err(dev, "Cannot write ctrl register\n"); 129 goto brightness_out; 130 } 131 132 led->enabled = LED_OFF; 133 } else { 134 ret = ti_lmu_common_set_brightness(&led->lmu_data, brt_val); 135 if (ret) { 136 dev_err(dev, "Cannot write brightness\n"); 137 goto brightness_out; 138 } 139 140 if (!led->enabled) { 141 ret = regmap_update_bits(led->priv->regmap, 142 LM3697_CTRL_ENABLE, 143 ctrl_en_val, ctrl_en_val); 144 if (ret) { 145 dev_err(dev, "Cannot enable the device\n"); 146 goto brightness_out; 147 } 148 149 led->enabled = brt_val; 150 } 151 } 152 153 brightness_out: 154 mutex_unlock(&led->priv->lock); 155 return ret; 156 } 157 158 static int lm3697_init(struct lm3697 *priv) 159 { 160 struct device *dev = priv->dev; 161 struct lm3697_led *led; 162 int i, ret; 163 164 if (priv->enable_gpio) { 165 gpiod_direction_output(priv->enable_gpio, 1); 166 } else { 167 ret = regmap_write(priv->regmap, LM3697_RESET, LM3697_SW_RESET); 168 if (ret) { 169 dev_err(dev, "Cannot reset the device\n"); 170 goto out; 171 } 172 } 173 174 ret = regmap_write(priv->regmap, LM3697_CTRL_ENABLE, 0x0); 175 if (ret) { 176 dev_err(dev, "Cannot write ctrl enable\n"); 177 goto out; 178 } 179 180 ret = regmap_write(priv->regmap, LM3697_OUTPUT_CONFIG, priv->bank_cfg); 181 if (ret) 182 dev_err(dev, "Cannot write OUTPUT config\n"); 183 184 for (i = 0; i < priv->num_banks; i++) { 185 led = &priv->leds[i]; 186 ret = ti_lmu_common_set_ramp(&led->lmu_data); 187 if (ret) 188 dev_err(dev, "Setting the ramp rate failed\n"); 189 } 190 out: 191 return ret; 192 } 193 194 static int lm3697_probe_dt(struct lm3697 *priv) 195 { 196 struct fwnode_handle *child = NULL; 197 struct device *dev = priv->dev; 198 struct lm3697_led *led; 199 int ret = -EINVAL; 200 int control_bank; 201 size_t i = 0; 202 int j; 203 204 priv->enable_gpio = devm_gpiod_get_optional(dev, "enable", 205 GPIOD_OUT_LOW); 206 if (IS_ERR(priv->enable_gpio)) { 207 ret = PTR_ERR(priv->enable_gpio); 208 dev_err(dev, "Failed to get enable gpio: %d\n", ret); 209 return ret; 210 } 211 212 priv->regulator = devm_regulator_get(dev, "vled"); 213 if (IS_ERR(priv->regulator)) 214 priv->regulator = NULL; 215 216 device_for_each_child_node(dev, child) { 217 struct led_init_data init_data = {}; 218 219 ret = fwnode_property_read_u32(child, "reg", &control_bank); 220 if (ret) { 221 dev_err(dev, "reg property missing\n"); 222 fwnode_handle_put(child); 223 goto child_out; 224 } 225 226 if (control_bank > LM3697_CONTROL_B) { 227 dev_err(dev, "reg property is invalid\n"); 228 ret = -EINVAL; 229 fwnode_handle_put(child); 230 goto child_out; 231 } 232 233 led = &priv->leds[i]; 234 235 ret = ti_lmu_common_get_brt_res(dev, child, &led->lmu_data); 236 if (ret) 237 dev_warn(dev, 238 "brightness resolution property missing\n"); 239 240 led->control_bank = control_bank; 241 led->lmu_data.regmap = priv->regmap; 242 led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP + 243 control_bank; 244 led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB + 245 led->control_bank * 2; 246 led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB + 247 led->control_bank * 2; 248 249 led->num_leds = fwnode_property_count_u32(child, "led-sources"); 250 if (led->num_leds > LM3697_MAX_LED_STRINGS) { 251 dev_err(dev, "Too many LED strings defined\n"); 252 continue; 253 } 254 255 ret = fwnode_property_read_u32_array(child, "led-sources", 256 led->hvled_strings, 257 led->num_leds); 258 if (ret) { 259 dev_err(dev, "led-sources property missing\n"); 260 fwnode_handle_put(child); 261 goto child_out; 262 } 263 264 for (j = 0; j < led->num_leds; j++) 265 priv->bank_cfg |= 266 (led->control_bank << led->hvled_strings[j]); 267 268 ret = ti_lmu_common_get_ramp_params(dev, child, &led->lmu_data); 269 if (ret) 270 dev_warn(dev, "runtime-ramp properties missing\n"); 271 272 init_data.fwnode = child; 273 init_data.devicename = priv->client->name; 274 /* for backwards compatibility if `label` is not present */ 275 init_data.default_label = ":"; 276 277 led->priv = priv; 278 led->led_dev.max_brightness = led->lmu_data.max_brightness; 279 led->led_dev.brightness_set_blocking = lm3697_brightness_set; 280 281 ret = devm_led_classdev_register_ext(dev, &led->led_dev, 282 &init_data); 283 if (ret) { 284 dev_err(dev, "led register err: %d\n", ret); 285 fwnode_handle_put(child); 286 goto child_out; 287 } 288 289 i++; 290 } 291 292 child_out: 293 return ret; 294 } 295 296 static int lm3697_probe(struct i2c_client *client, 297 const struct i2c_device_id *id) 298 { 299 struct device *dev = &client->dev; 300 struct lm3697 *led; 301 int count; 302 int ret; 303 304 count = device_get_child_node_count(dev); 305 if (!count || count > LM3697_MAX_CONTROL_BANKS) { 306 dev_err(dev, "Strange device tree!"); 307 return -ENODEV; 308 } 309 310 led = devm_kzalloc(dev, struct_size(led, leds, count), GFP_KERNEL); 311 if (!led) 312 return -ENOMEM; 313 314 mutex_init(&led->lock); 315 i2c_set_clientdata(client, led); 316 317 led->client = client; 318 led->dev = dev; 319 led->num_banks = count; 320 led->regmap = devm_regmap_init_i2c(client, &lm3697_regmap_config); 321 if (IS_ERR(led->regmap)) { 322 ret = PTR_ERR(led->regmap); 323 dev_err(dev, "Failed to allocate register map: %d\n", ret); 324 return ret; 325 } 326 327 ret = lm3697_probe_dt(led); 328 if (ret) 329 return ret; 330 331 return lm3697_init(led); 332 } 333 334 static int lm3697_remove(struct i2c_client *client) 335 { 336 struct lm3697 *led = i2c_get_clientdata(client); 337 struct device *dev = &led->client->dev; 338 int ret; 339 340 ret = regmap_update_bits(led->regmap, LM3697_CTRL_ENABLE, 341 LM3697_CTRL_A_B_EN, 0); 342 if (ret) { 343 dev_err(dev, "Failed to disable the device\n"); 344 return ret; 345 } 346 347 if (led->enable_gpio) 348 gpiod_direction_output(led->enable_gpio, 0); 349 350 if (led->regulator) { 351 ret = regulator_disable(led->regulator); 352 if (ret) 353 dev_err(dev, "Failed to disable regulator\n"); 354 } 355 356 mutex_destroy(&led->lock); 357 358 return 0; 359 } 360 361 static const struct i2c_device_id lm3697_id[] = { 362 { "lm3697", 0 }, 363 { } 364 }; 365 MODULE_DEVICE_TABLE(i2c, lm3697_id); 366 367 static const struct of_device_id of_lm3697_leds_match[] = { 368 { .compatible = "ti,lm3697", }, 369 {}, 370 }; 371 MODULE_DEVICE_TABLE(of, of_lm3697_leds_match); 372 373 static struct i2c_driver lm3697_driver = { 374 .driver = { 375 .name = "lm3697", 376 .of_match_table = of_lm3697_leds_match, 377 }, 378 .probe = lm3697_probe, 379 .remove = lm3697_remove, 380 .id_table = lm3697_id, 381 }; 382 module_i2c_driver(lm3697_driver); 383 384 MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver"); 385 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); 386 MODULE_LICENSE("GPL v2"); 387