1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for ISSI IS31FL32xx family of I2C LED controllers 4 * 5 * Copyright 2015 Allworx Corp. 6 * 7 * Datasheets: 8 * http://www.issi.com/US/product-analog-fxled-driver.shtml 9 * http://www.si-en.com/product.asp?parentid=890 10 */ 11 12 #include <linux/device.h> 13 #include <linux/i2c.h> 14 #include <linux/kernel.h> 15 #include <linux/leds.h> 16 #include <linux/module.h> 17 #include <linux/of.h> 18 #include <linux/of_device.h> 19 20 /* Used to indicate a device has no such register */ 21 #define IS31FL32XX_REG_NONE 0xFF 22 23 /* Software Shutdown bit in Shutdown Register */ 24 #define IS31FL32XX_SHUTDOWN_SSD_ENABLE 0 25 #define IS31FL32XX_SHUTDOWN_SSD_DISABLE BIT(0) 26 27 /* IS31FL3216 has a number of unique registers */ 28 #define IS31FL3216_CONFIG_REG 0x00 29 #define IS31FL3216_LIGHTING_EFFECT_REG 0x03 30 #define IS31FL3216_CHANNEL_CONFIG_REG 0x04 31 32 /* Software Shutdown bit in 3216 Config Register */ 33 #define IS31FL3216_CONFIG_SSD_ENABLE BIT(7) 34 #define IS31FL3216_CONFIG_SSD_DISABLE 0 35 36 struct is31fl32xx_priv; 37 struct is31fl32xx_led_data { 38 struct led_classdev cdev; 39 u8 channel; /* 1-based, max priv->cdef->channels */ 40 struct is31fl32xx_priv *priv; 41 }; 42 43 struct is31fl32xx_priv { 44 const struct is31fl32xx_chipdef *cdef; 45 struct i2c_client *client; 46 unsigned int num_leds; 47 struct is31fl32xx_led_data leds[]; 48 }; 49 50 /** 51 * struct is31fl32xx_chipdef - chip-specific attributes 52 * @channels : Number of LED channels 53 * @shutdown_reg : address of Shutdown register (optional) 54 * @pwm_update_reg : address of PWM Update register 55 * @global_control_reg : address of Global Control register (optional) 56 * @reset_reg : address of Reset register (optional) 57 * @pwm_register_base : address of first PWM register 58 * @pwm_registers_reversed: : true if PWM registers count down instead of up 59 * @led_control_register_base : address of first LED control register (optional) 60 * @enable_bits_per_led_control_register: number of LEDs enable bits in each 61 * @reset_func : pointer to reset function 62 * @sw_shutdown_func : pointer to software shutdown function 63 * 64 * For all optional register addresses, the sentinel value %IS31FL32XX_REG_NONE 65 * indicates that this chip has no such register. 66 * 67 * If non-NULL, @reset_func will be called during probing to set all 68 * necessary registers to a known initialization state. This is needed 69 * for chips that do not have a @reset_reg. 70 * 71 * @enable_bits_per_led_control_register must be >=1 if 72 * @led_control_register_base != %IS31FL32XX_REG_NONE. 73 */ 74 struct is31fl32xx_chipdef { 75 u8 channels; 76 u8 shutdown_reg; 77 u8 pwm_update_reg; 78 u8 global_control_reg; 79 u8 reset_reg; 80 u8 pwm_register_base; 81 bool pwm_registers_reversed; 82 u8 led_control_register_base; 83 u8 enable_bits_per_led_control_register; 84 int (*reset_func)(struct is31fl32xx_priv *priv); 85 int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable); 86 }; 87 88 static const struct is31fl32xx_chipdef is31fl3236_cdef = { 89 .channels = 36, 90 .shutdown_reg = 0x00, 91 .pwm_update_reg = 0x25, 92 .global_control_reg = 0x4a, 93 .reset_reg = 0x4f, 94 .pwm_register_base = 0x01, 95 .led_control_register_base = 0x26, 96 .enable_bits_per_led_control_register = 1, 97 }; 98 99 static const struct is31fl32xx_chipdef is31fl3235_cdef = { 100 .channels = 28, 101 .shutdown_reg = 0x00, 102 .pwm_update_reg = 0x25, 103 .global_control_reg = 0x4a, 104 .reset_reg = 0x4f, 105 .pwm_register_base = 0x05, 106 .led_control_register_base = 0x2a, 107 .enable_bits_per_led_control_register = 1, 108 }; 109 110 static const struct is31fl32xx_chipdef is31fl3218_cdef = { 111 .channels = 18, 112 .shutdown_reg = 0x00, 113 .pwm_update_reg = 0x16, 114 .global_control_reg = IS31FL32XX_REG_NONE, 115 .reset_reg = 0x17, 116 .pwm_register_base = 0x01, 117 .led_control_register_base = 0x13, 118 .enable_bits_per_led_control_register = 6, 119 }; 120 121 static int is31fl3216_reset(struct is31fl32xx_priv *priv); 122 static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv, 123 bool enable); 124 static const struct is31fl32xx_chipdef is31fl3216_cdef = { 125 .channels = 16, 126 .shutdown_reg = IS31FL32XX_REG_NONE, 127 .pwm_update_reg = 0xB0, 128 .global_control_reg = IS31FL32XX_REG_NONE, 129 .reset_reg = IS31FL32XX_REG_NONE, 130 .pwm_register_base = 0x10, 131 .pwm_registers_reversed = true, 132 .led_control_register_base = 0x01, 133 .enable_bits_per_led_control_register = 8, 134 .reset_func = is31fl3216_reset, 135 .sw_shutdown_func = is31fl3216_software_shutdown, 136 }; 137 138 static int is31fl32xx_write(struct is31fl32xx_priv *priv, u8 reg, u8 val) 139 { 140 int ret; 141 142 dev_dbg(&priv->client->dev, "writing register 0x%02X=0x%02X", reg, val); 143 144 ret = i2c_smbus_write_byte_data(priv->client, reg, val); 145 if (ret) { 146 dev_err(&priv->client->dev, 147 "register write to 0x%02X failed (error %d)", 148 reg, ret); 149 } 150 return ret; 151 } 152 153 /* 154 * Custom reset function for IS31FL3216 because it does not have a RESET 155 * register the way that the other IS31FL32xx chips do. We don't bother 156 * writing the GPIO and animation registers, because the registers we 157 * do write ensure those will have no effect. 158 */ 159 static int is31fl3216_reset(struct is31fl32xx_priv *priv) 160 { 161 unsigned int i; 162 int ret; 163 164 ret = is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, 165 IS31FL3216_CONFIG_SSD_ENABLE); 166 if (ret) 167 return ret; 168 for (i = 0; i < priv->cdef->channels; i++) { 169 ret = is31fl32xx_write(priv, priv->cdef->pwm_register_base+i, 170 0x00); 171 if (ret) 172 return ret; 173 } 174 ret = is31fl32xx_write(priv, priv->cdef->pwm_update_reg, 0); 175 if (ret) 176 return ret; 177 ret = is31fl32xx_write(priv, IS31FL3216_LIGHTING_EFFECT_REG, 0x00); 178 if (ret) 179 return ret; 180 ret = is31fl32xx_write(priv, IS31FL3216_CHANNEL_CONFIG_REG, 0x00); 181 if (ret) 182 return ret; 183 184 return 0; 185 } 186 187 /* 188 * Custom Software-Shutdown function for IS31FL3216 because it does not have 189 * a SHUTDOWN register the way that the other IS31FL32xx chips do. 190 * We don't bother doing a read/modify/write on the CONFIG register because 191 * we only ever use a value of '0' for the other fields in that register. 192 */ 193 static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv, 194 bool enable) 195 { 196 u8 value = enable ? IS31FL3216_CONFIG_SSD_ENABLE : 197 IS31FL3216_CONFIG_SSD_DISABLE; 198 199 return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value); 200 } 201 202 /* 203 * NOTE: A mutex is not needed in this function because: 204 * - All referenced data is read-only after probe() 205 * - The I2C core has a mutex on to protect the bus 206 * - There are no read/modify/write operations 207 * - Intervening operations between the write of the PWM register 208 * and the Update register are harmless. 209 * 210 * Example: 211 * PWM_REG_1 write 16 212 * UPDATE_REG write 0 213 * PWM_REG_2 write 128 214 * UPDATE_REG write 0 215 * vs: 216 * PWM_REG_1 write 16 217 * PWM_REG_2 write 128 218 * UPDATE_REG write 0 219 * UPDATE_REG write 0 220 * are equivalent. Poking the Update register merely applies all PWM 221 * register writes up to that point. 222 */ 223 static int is31fl32xx_brightness_set(struct led_classdev *led_cdev, 224 enum led_brightness brightness) 225 { 226 const struct is31fl32xx_led_data *led_data = 227 container_of(led_cdev, struct is31fl32xx_led_data, cdev); 228 const struct is31fl32xx_chipdef *cdef = led_data->priv->cdef; 229 u8 pwm_register_offset; 230 int ret; 231 232 dev_dbg(led_cdev->dev, "%s: %d\n", __func__, brightness); 233 234 /* NOTE: led_data->channel is 1-based */ 235 if (cdef->pwm_registers_reversed) 236 pwm_register_offset = cdef->channels - led_data->channel; 237 else 238 pwm_register_offset = led_data->channel - 1; 239 240 ret = is31fl32xx_write(led_data->priv, 241 cdef->pwm_register_base + pwm_register_offset, 242 brightness); 243 if (ret) 244 return ret; 245 246 return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0); 247 } 248 249 static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv) 250 { 251 const struct is31fl32xx_chipdef *cdef = priv->cdef; 252 int ret; 253 254 if (cdef->reset_reg != IS31FL32XX_REG_NONE) { 255 ret = is31fl32xx_write(priv, cdef->reset_reg, 0); 256 if (ret) 257 return ret; 258 } 259 260 if (cdef->reset_func) 261 return cdef->reset_func(priv); 262 263 return 0; 264 } 265 266 static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv, 267 bool enable) 268 { 269 const struct is31fl32xx_chipdef *cdef = priv->cdef; 270 int ret; 271 272 if (cdef->shutdown_reg != IS31FL32XX_REG_NONE) { 273 u8 value = enable ? IS31FL32XX_SHUTDOWN_SSD_ENABLE : 274 IS31FL32XX_SHUTDOWN_SSD_DISABLE; 275 ret = is31fl32xx_write(priv, cdef->shutdown_reg, value); 276 if (ret) 277 return ret; 278 } 279 280 if (cdef->sw_shutdown_func) 281 return cdef->sw_shutdown_func(priv, enable); 282 283 return 0; 284 } 285 286 static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv) 287 { 288 const struct is31fl32xx_chipdef *cdef = priv->cdef; 289 int ret; 290 291 ret = is31fl32xx_reset_regs(priv); 292 if (ret) 293 return ret; 294 295 /* 296 * Set enable bit for all channels. 297 * We will control state with PWM registers alone. 298 */ 299 if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) { 300 u8 value = 301 GENMASK(cdef->enable_bits_per_led_control_register-1, 0); 302 u8 num_regs = cdef->channels / 303 cdef->enable_bits_per_led_control_register; 304 int i; 305 306 for (i = 0; i < num_regs; i++) { 307 ret = is31fl32xx_write(priv, 308 cdef->led_control_register_base+i, 309 value); 310 if (ret) 311 return ret; 312 } 313 } 314 315 ret = is31fl32xx_software_shutdown(priv, false); 316 if (ret) 317 return ret; 318 319 if (cdef->global_control_reg != IS31FL32XX_REG_NONE) { 320 ret = is31fl32xx_write(priv, cdef->global_control_reg, 0x00); 321 if (ret) 322 return ret; 323 } 324 325 return 0; 326 } 327 328 static int is31fl32xx_parse_child_dt(const struct device *dev, 329 const struct device_node *child, 330 struct is31fl32xx_led_data *led_data) 331 { 332 struct led_classdev *cdev = &led_data->cdev; 333 int ret = 0; 334 u32 reg; 335 336 ret = of_property_read_u32(child, "reg", ®); 337 if (ret || reg < 1 || reg > led_data->priv->cdef->channels) { 338 dev_err(dev, 339 "Child node %pOF does not have a valid reg property\n", 340 child); 341 return -EINVAL; 342 } 343 led_data->channel = reg; 344 345 cdev->brightness_set_blocking = is31fl32xx_brightness_set; 346 347 return 0; 348 } 349 350 static struct is31fl32xx_led_data *is31fl32xx_find_led_data( 351 struct is31fl32xx_priv *priv, 352 u8 channel) 353 { 354 size_t i; 355 356 for (i = 0; i < priv->num_leds; i++) { 357 if (priv->leds[i].channel == channel) 358 return &priv->leds[i]; 359 } 360 361 return NULL; 362 } 363 364 static int is31fl32xx_parse_dt(struct device *dev, 365 struct is31fl32xx_priv *priv) 366 { 367 struct device_node *child; 368 int ret = 0; 369 370 for_each_available_child_of_node(dev_of_node(dev), child) { 371 struct led_init_data init_data = {}; 372 struct is31fl32xx_led_data *led_data = 373 &priv->leds[priv->num_leds]; 374 const struct is31fl32xx_led_data *other_led_data; 375 376 led_data->priv = priv; 377 378 ret = is31fl32xx_parse_child_dt(dev, child, led_data); 379 if (ret) 380 goto err; 381 382 /* Detect if channel is already in use by another child */ 383 other_led_data = is31fl32xx_find_led_data(priv, 384 led_data->channel); 385 if (other_led_data) { 386 dev_err(dev, 387 "Node %pOF 'reg' conflicts with another LED\n", 388 child); 389 ret = -EINVAL; 390 goto err; 391 } 392 393 init_data.fwnode = of_fwnode_handle(child); 394 395 ret = devm_led_classdev_register_ext(dev, &led_data->cdev, 396 &init_data); 397 if (ret) { 398 dev_err(dev, "Failed to register LED for %pOF: %d\n", 399 child, ret); 400 goto err; 401 } 402 403 priv->num_leds++; 404 } 405 406 return 0; 407 408 err: 409 of_node_put(child); 410 return ret; 411 } 412 413 static const struct of_device_id of_is31fl32xx_match[] = { 414 { .compatible = "issi,is31fl3236", .data = &is31fl3236_cdef, }, 415 { .compatible = "issi,is31fl3235", .data = &is31fl3235_cdef, }, 416 { .compatible = "issi,is31fl3218", .data = &is31fl3218_cdef, }, 417 { .compatible = "si-en,sn3218", .data = &is31fl3218_cdef, }, 418 { .compatible = "issi,is31fl3216", .data = &is31fl3216_cdef, }, 419 { .compatible = "si-en,sn3216", .data = &is31fl3216_cdef, }, 420 {}, 421 }; 422 423 MODULE_DEVICE_TABLE(of, of_is31fl32xx_match); 424 425 static int is31fl32xx_probe(struct i2c_client *client) 426 { 427 const struct is31fl32xx_chipdef *cdef; 428 struct device *dev = &client->dev; 429 struct is31fl32xx_priv *priv; 430 int count; 431 int ret = 0; 432 433 cdef = device_get_match_data(dev); 434 435 count = of_get_available_child_count(dev_of_node(dev)); 436 if (!count) 437 return -EINVAL; 438 439 priv = devm_kzalloc(dev, struct_size(priv, leds, count), 440 GFP_KERNEL); 441 if (!priv) 442 return -ENOMEM; 443 444 priv->client = client; 445 priv->cdef = cdef; 446 i2c_set_clientdata(client, priv); 447 448 ret = is31fl32xx_init_regs(priv); 449 if (ret) 450 return ret; 451 452 ret = is31fl32xx_parse_dt(dev, priv); 453 if (ret) 454 return ret; 455 456 return 0; 457 } 458 459 static void is31fl32xx_remove(struct i2c_client *client) 460 { 461 struct is31fl32xx_priv *priv = i2c_get_clientdata(client); 462 int ret; 463 464 ret = is31fl32xx_reset_regs(priv); 465 if (ret) 466 dev_err(&client->dev, "Failed to reset registers on removal (%pe)\n", 467 ERR_PTR(ret)); 468 } 469 470 /* 471 * i2c-core (and modalias) requires that id_table be properly filled, 472 * even though it is not used for DeviceTree based instantiation. 473 */ 474 static const struct i2c_device_id is31fl32xx_id[] = { 475 { "is31fl3236" }, 476 { "is31fl3235" }, 477 { "is31fl3218" }, 478 { "sn3218" }, 479 { "is31fl3216" }, 480 { "sn3216" }, 481 {}, 482 }; 483 484 MODULE_DEVICE_TABLE(i2c, is31fl32xx_id); 485 486 static struct i2c_driver is31fl32xx_driver = { 487 .driver = { 488 .name = "is31fl32xx", 489 .of_match_table = of_is31fl32xx_match, 490 }, 491 .probe = is31fl32xx_probe, 492 .remove = is31fl32xx_remove, 493 .id_table = is31fl32xx_id, 494 }; 495 496 module_i2c_driver(is31fl32xx_driver); 497 498 MODULE_AUTHOR("David Rivshin <drivshin@allworx.com>"); 499 MODULE_DESCRIPTION("ISSI IS31FL32xx LED driver"); 500 MODULE_LICENSE("GPL v2"); 501