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/bits.h> 6 #include <linux/gpio/consumer.h> 7 #include <linux/i2c.h> 8 #include <linux/mod_devicetable.h> 9 #include <linux/module.h> 10 #include <linux/property.h> 11 #include <linux/regmap.h> 12 #include <linux/regulator/consumer.h> 13 #include <linux/types.h> 14 15 #include <linux/leds-ti-lmu-common.h> 16 17 #define LM3697_REV 0x0 18 #define LM3697_RESET 0x1 19 #define LM3697_OUTPUT_CONFIG 0x10 20 #define LM3697_CTRL_A_RAMP 0x11 21 #define LM3697_CTRL_B_RAMP 0x12 22 #define LM3697_CTRL_A_B_RT_RAMP 0x13 23 #define LM3697_CTRL_A_B_RAMP_CFG 0x14 24 #define LM3697_CTRL_A_B_BRT_CFG 0x16 25 #define LM3697_CTRL_A_FS_CURR_CFG 0x17 26 #define LM3697_CTRL_B_FS_CURR_CFG 0x18 27 #define LM3697_PWM_CFG 0x1c 28 #define LM3697_CTRL_A_BRT_LSB 0x20 29 #define LM3697_CTRL_A_BRT_MSB 0x21 30 #define LM3697_CTRL_B_BRT_LSB 0x22 31 #define LM3697_CTRL_B_BRT_MSB 0x23 32 #define LM3697_CTRL_ENABLE 0x24 33 34 #define LM3697_SW_RESET BIT(0) 35 36 #define LM3697_CTRL_A_EN BIT(0) 37 #define LM3697_CTRL_B_EN BIT(1) 38 #define LM3697_CTRL_A_B_EN (LM3697_CTRL_A_EN | LM3697_CTRL_B_EN) 39 40 #define LM3697_MAX_LED_STRINGS 3 41 42 #define LM3697_CONTROL_A 0 43 #define LM3697_CONTROL_B 1 44 #define LM3697_MAX_CONTROL_BANKS 2 45 46 /** 47 * struct lm3697_led - 48 * @hvled_strings: Array of LED strings associated with a control bank 49 * @label: LED label 50 * @led_dev: LED class device 51 * @priv: Pointer to the device struct 52 * @lmu_data: Register and setting values for common code 53 * @control_bank: Control bank the LED is associated to. 0 is control bank A 54 * 1 is control bank B 55 * @enabled: LED brightness level (or LED_OFF) 56 * @num_leds: Number of LEDs available 57 */ 58 struct lm3697_led { 59 u32 hvled_strings[LM3697_MAX_LED_STRINGS]; 60 char label[LED_MAX_NAME_SIZE]; 61 struct led_classdev led_dev; 62 struct lm3697 *priv; 63 struct ti_lmu_bank lmu_data; 64 int control_bank; 65 int enabled; 66 int num_leds; 67 }; 68 69 /** 70 * struct lm3697 - 71 * @enable_gpio: Hardware enable gpio 72 * @regulator: LED supply regulator pointer 73 * @client: Pointer to the I2C client 74 * @regmap: Devices register map 75 * @dev: Pointer to the devices device struct 76 * @lock: Lock for reading/writing the device 77 * @leds: Array of LED strings 78 * @bank_cfg: OUTPUT_CONFIG register values 79 * @num_banks: Number of control banks 80 */ 81 struct lm3697 { 82 struct gpio_desc *enable_gpio; 83 struct regulator *regulator; 84 struct i2c_client *client; 85 struct regmap *regmap; 86 struct device *dev; 87 struct mutex lock; 88 89 int bank_cfg; 90 int num_banks; 91 92 struct lm3697_led leds[]; 93 }; 94 95 static const struct reg_default lm3697_reg_defs[] = { 96 {LM3697_OUTPUT_CONFIG, 0x6}, 97 {LM3697_CTRL_A_RAMP, 0x0}, 98 {LM3697_CTRL_B_RAMP, 0x0}, 99 {LM3697_CTRL_A_B_RT_RAMP, 0x0}, 100 {LM3697_CTRL_A_B_RAMP_CFG, 0x0}, 101 {LM3697_CTRL_A_B_BRT_CFG, 0x0}, 102 {LM3697_CTRL_A_FS_CURR_CFG, 0x13}, 103 {LM3697_CTRL_B_FS_CURR_CFG, 0x13}, 104 {LM3697_PWM_CFG, 0xc}, 105 {LM3697_CTRL_A_BRT_LSB, 0x0}, 106 {LM3697_CTRL_A_BRT_MSB, 0x0}, 107 {LM3697_CTRL_B_BRT_LSB, 0x0}, 108 {LM3697_CTRL_B_BRT_MSB, 0x0}, 109 {LM3697_CTRL_ENABLE, 0x0}, 110 }; 111 112 static const struct regmap_config lm3697_regmap_config = { 113 .reg_bits = 8, 114 .val_bits = 8, 115 116 .max_register = LM3697_CTRL_ENABLE, 117 .reg_defaults = lm3697_reg_defs, 118 .num_reg_defaults = ARRAY_SIZE(lm3697_reg_defs), 119 .cache_type = REGCACHE_FLAT, 120 }; 121 122 static int lm3697_brightness_set(struct led_classdev *led_cdev, 123 enum led_brightness brt_val) 124 { 125 struct lm3697_led *led = container_of(led_cdev, struct lm3697_led, 126 led_dev); 127 int ctrl_en_val = (1 << led->control_bank); 128 struct device *dev = led->priv->dev; 129 int ret; 130 131 mutex_lock(&led->priv->lock); 132 133 if (brt_val == LED_OFF) { 134 ret = regmap_update_bits(led->priv->regmap, LM3697_CTRL_ENABLE, 135 ctrl_en_val, ~ctrl_en_val); 136 if (ret) { 137 dev_err(dev, "Cannot write ctrl register\n"); 138 goto brightness_out; 139 } 140 141 led->enabled = LED_OFF; 142 } else { 143 ret = ti_lmu_common_set_brightness(&led->lmu_data, brt_val); 144 if (ret) { 145 dev_err(dev, "Cannot write brightness\n"); 146 goto brightness_out; 147 } 148 149 if (!led->enabled) { 150 ret = regmap_update_bits(led->priv->regmap, 151 LM3697_CTRL_ENABLE, 152 ctrl_en_val, ctrl_en_val); 153 if (ret) { 154 dev_err(dev, "Cannot enable the device\n"); 155 goto brightness_out; 156 } 157 158 led->enabled = brt_val; 159 } 160 } 161 162 brightness_out: 163 mutex_unlock(&led->priv->lock); 164 return ret; 165 } 166 167 static int lm3697_init(struct lm3697 *priv) 168 { 169 struct device *dev = priv->dev; 170 struct lm3697_led *led; 171 int i, ret; 172 173 if (priv->enable_gpio) { 174 gpiod_direction_output(priv->enable_gpio, 1); 175 } else { 176 ret = regmap_write(priv->regmap, LM3697_RESET, LM3697_SW_RESET); 177 if (ret) { 178 dev_err(dev, "Cannot reset the device\n"); 179 goto out; 180 } 181 } 182 183 ret = regmap_write(priv->regmap, LM3697_CTRL_ENABLE, 0x0); 184 if (ret) { 185 dev_err(dev, "Cannot write ctrl enable\n"); 186 goto out; 187 } 188 189 ret = regmap_write(priv->regmap, LM3697_OUTPUT_CONFIG, priv->bank_cfg); 190 if (ret) 191 dev_err(dev, "Cannot write OUTPUT config\n"); 192 193 for (i = 0; i < priv->num_banks; i++) { 194 led = &priv->leds[i]; 195 ret = ti_lmu_common_set_ramp(&led->lmu_data); 196 if (ret) 197 dev_err(dev, "Setting the ramp rate failed\n"); 198 } 199 out: 200 return ret; 201 } 202 203 static int lm3697_probe_dt(struct lm3697 *priv) 204 { 205 struct fwnode_handle *child = NULL; 206 struct device *dev = priv->dev; 207 struct lm3697_led *led; 208 int ret = -EINVAL; 209 int control_bank; 210 size_t i = 0; 211 int j; 212 213 priv->enable_gpio = devm_gpiod_get_optional(dev, "enable", 214 GPIOD_OUT_LOW); 215 if (IS_ERR(priv->enable_gpio)) 216 return dev_err_probe(dev, PTR_ERR(priv->enable_gpio), 217 "Failed to get enable GPIO\n"); 218 219 priv->regulator = devm_regulator_get(dev, "vled"); 220 if (IS_ERR(priv->regulator)) 221 priv->regulator = NULL; 222 223 device_for_each_child_node(dev, child) { 224 struct led_init_data init_data = {}; 225 226 ret = fwnode_property_read_u32(child, "reg", &control_bank); 227 if (ret) { 228 dev_err(dev, "reg property missing\n"); 229 goto child_out; 230 } 231 232 if (control_bank > LM3697_CONTROL_B) { 233 dev_err(dev, "reg property is invalid\n"); 234 ret = -EINVAL; 235 goto child_out; 236 } 237 238 led = &priv->leds[i]; 239 240 ret = ti_lmu_common_get_brt_res(dev, child, &led->lmu_data); 241 if (ret) 242 dev_warn(dev, 243 "brightness resolution property missing\n"); 244 245 led->control_bank = control_bank; 246 led->lmu_data.regmap = priv->regmap; 247 led->lmu_data.runtime_ramp_reg = LM3697_CTRL_A_RAMP + 248 control_bank; 249 led->lmu_data.msb_brightness_reg = LM3697_CTRL_A_BRT_MSB + 250 led->control_bank * 2; 251 led->lmu_data.lsb_brightness_reg = LM3697_CTRL_A_BRT_LSB + 252 led->control_bank * 2; 253 254 led->num_leds = fwnode_property_count_u32(child, "led-sources"); 255 if (led->num_leds > LM3697_MAX_LED_STRINGS) { 256 dev_err(dev, "Too many LED strings defined\n"); 257 continue; 258 } 259 260 ret = fwnode_property_read_u32_array(child, "led-sources", 261 led->hvled_strings, 262 led->num_leds); 263 if (ret) { 264 dev_err(dev, "led-sources property missing\n"); 265 goto child_out; 266 } 267 268 for (j = 0; j < led->num_leds; j++) 269 priv->bank_cfg |= 270 (led->control_bank << led->hvled_strings[j]); 271 272 ret = ti_lmu_common_get_ramp_params(dev, child, &led->lmu_data); 273 if (ret) 274 dev_warn(dev, "runtime-ramp properties missing\n"); 275 276 init_data.fwnode = child; 277 init_data.devicename = priv->client->name; 278 /* for backwards compatibility if `label` is not present */ 279 init_data.default_label = ":"; 280 281 led->priv = priv; 282 led->led_dev.max_brightness = led->lmu_data.max_brightness; 283 led->led_dev.brightness_set_blocking = lm3697_brightness_set; 284 285 ret = devm_led_classdev_register_ext(dev, &led->led_dev, 286 &init_data); 287 if (ret) { 288 dev_err(dev, "led register err: %d\n", ret); 289 goto child_out; 290 } 291 292 i++; 293 } 294 295 return ret; 296 297 child_out: 298 fwnode_handle_put(child); 299 return ret; 300 } 301 302 static int lm3697_probe(struct i2c_client *client, 303 const struct i2c_device_id *id) 304 { 305 struct device *dev = &client->dev; 306 struct lm3697 *led; 307 int count; 308 int ret; 309 310 count = device_get_child_node_count(dev); 311 if (!count || count > LM3697_MAX_CONTROL_BANKS) { 312 dev_err(dev, "Strange device tree!"); 313 return -ENODEV; 314 } 315 316 led = devm_kzalloc(dev, struct_size(led, leds, count), GFP_KERNEL); 317 if (!led) 318 return -ENOMEM; 319 320 mutex_init(&led->lock); 321 i2c_set_clientdata(client, led); 322 323 led->client = client; 324 led->dev = dev; 325 led->num_banks = count; 326 led->regmap = devm_regmap_init_i2c(client, &lm3697_regmap_config); 327 if (IS_ERR(led->regmap)) { 328 ret = PTR_ERR(led->regmap); 329 dev_err(dev, "Failed to allocate register map: %d\n", ret); 330 return ret; 331 } 332 333 ret = lm3697_probe_dt(led); 334 if (ret) 335 return ret; 336 337 return lm3697_init(led); 338 } 339 340 static void lm3697_remove(struct i2c_client *client) 341 { 342 struct lm3697 *led = i2c_get_clientdata(client); 343 struct device *dev = &led->client->dev; 344 int ret; 345 346 ret = regmap_update_bits(led->regmap, LM3697_CTRL_ENABLE, 347 LM3697_CTRL_A_B_EN, 0); 348 if (ret) 349 dev_err(dev, "Failed to disable the device\n"); 350 351 if (led->enable_gpio) 352 gpiod_direction_output(led->enable_gpio, 0); 353 354 if (led->regulator) { 355 ret = regulator_disable(led->regulator); 356 if (ret) 357 dev_err(dev, "Failed to disable regulator\n"); 358 } 359 360 mutex_destroy(&led->lock); 361 } 362 363 static const struct i2c_device_id lm3697_id[] = { 364 { "lm3697", 0 }, 365 { } 366 }; 367 MODULE_DEVICE_TABLE(i2c, lm3697_id); 368 369 static const struct of_device_id of_lm3697_leds_match[] = { 370 { .compatible = "ti,lm3697", }, 371 {}, 372 }; 373 MODULE_DEVICE_TABLE(of, of_lm3697_leds_match); 374 375 static struct i2c_driver lm3697_driver = { 376 .driver = { 377 .name = "lm3697", 378 .of_match_table = of_lm3697_leds_match, 379 }, 380 .probe = lm3697_probe, 381 .remove = lm3697_remove, 382 .id_table = lm3697_id, 383 }; 384 module_i2c_driver(lm3697_driver); 385 386 MODULE_DESCRIPTION("Texas Instruments LM3697 LED driver"); 387 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>"); 388 MODULE_LICENSE("GPL v2"); 389