drivers/leds/leds-tlc591xx.c

   1 /*
   2  * Copyright 2014 Belkin Inc.
   3  * Copyright 2015 Andrew Lunn <andrew@lunn.ch>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; version 2 of the License.
   8  */
   9
  10 #include <linux/i2c.h>
  11 #include <linux/leds.h>
  12 #include <linux/module.h>
  13 #include <linux/of.h>
  14 #include <linux/of_device.h>
  15 #include <linux/regmap.h>
  16 #include <linux/slab.h>
  17 #include <linux/workqueue.h>
  18
  19 #define TLC591XX_MAX_LEDS       16
  20
  21 #define TLC591XX_REG_MODE1      0x00
  22 #define MODE1_RESPON_ADDR_MASK  0xF0
  23 #define MODE1_NORMAL_MODE       (0 << 4)
  24 #define MODE1_SPEED_MODE        (1 << 4)
  25
  26 #define TLC591XX_REG_MODE2      0x01
  27 #define MODE2_DIM               (0 << 5)
  28 #define MODE2_BLINK             (1 << 5)
  29 #define MODE2_OCH_STOP          (0 << 3)
  30 #define MODE2_OCH_ACK           (1 << 3)
  31
  32 #define TLC591XX_REG_PWM(x)     (0x02 + (x))
  33
  34 #define TLC591XX_REG_GRPPWM     0x12
  35 #define TLC591XX_REG_GRPFREQ    0x13
  36
  37 /* LED Driver Output State, determine the source that drives LED outputs */
  38 #define LEDOUT_OFF              0x0     /* Output LOW */
  39 #define LEDOUT_ON               0x1     /* Output HI-Z */
  40 #define LEDOUT_DIM              0x2     /* Dimming */
  41 #define LEDOUT_BLINK            0x3     /* Blinking */
  42 #define LEDOUT_MASK             0x3
  43
  44 #define ldev_to_led(c)          container_of(c, struct tlc591xx_led, ldev)
  45 #define work_to_led(work)       container_of(work, struct tlc591xx_led, work)
  46
  47 struct tlc591xx_led {
  48         bool active;
  49         unsigned int led_no;
  50         struct led_classdev ldev;
  51         struct work_struct work;
  52         struct tlc591xx_priv *priv;
  53 };
  54
  55 struct tlc591xx_priv {
  56         struct tlc591xx_led leds[TLC591XX_MAX_LEDS];
  57         struct regmap *regmap;
  58         unsigned int reg_ledout_offset;
  59 };
  60
  61 struct tlc591xx {
  62         unsigned int max_leds;
  63         unsigned int reg_ledout_offset;
  64 };
  65
  66 static const struct tlc591xx tlc59116 = {
  67         .max_leds = 16,
  68         .reg_ledout_offset = 0x14,
  69 };
  70
  71 static const struct tlc591xx tlc59108 = {
  72         .max_leds = 8,
  73         .reg_ledout_offset = 0x0c,
  74 };
  75
  76 static int
  77 tlc591xx_set_mode(struct regmap *regmap, u8 mode)
  78 {
  79         int err;
  80         u8 val;
  81
  82         err = regmap_write(regmap, TLC591XX_REG_MODE1, MODE1_NORMAL_MODE);
  83         if (err)
  84                 return err;
  85
  86         val = MODE2_OCH_STOP | mode;
  87
  88         return regmap_write(regmap, TLC591XX_REG_MODE2, val);
  89 }
  90
  91 static int
  92 tlc591xx_set_ledout(struct tlc591xx_priv *priv, struct tlc591xx_led *led,
  93                     u8 val)
  94 {
  95         unsigned int i = (led->led_no % 4) * 2;
  96         unsigned int mask = LEDOUT_MASK << i;
  97         unsigned int addr = priv->reg_ledout_offset + (led->led_no >> 2);
  98
  99         val = val << i;
 100
 101         return regmap_update_bits(priv->regmap, addr, mask, val);
 102 }
 103
 104 static int
 105 tlc591xx_set_pwm(struct tlc591xx_priv *priv, struct tlc591xx_led *led,
 106                  u8 brightness)
 107 {
 108         u8 pwm = TLC591XX_REG_PWM(led->led_no);
 109
 110         return regmap_write(priv->regmap, pwm, brightness);
 111 }
 112
 113 static void
 114 tlc591xx_led_work(struct work_struct *work)
 115 {
 116         struct tlc591xx_led *led = work_to_led(work);
 117         struct tlc591xx_priv *priv = led->priv;
 118         enum led_brightness brightness = led->ldev.brightness;
 119         int err;
 120
 121         switch (brightness) {
 122         case 0:
 123                 err = tlc591xx_set_ledout(priv, led, LEDOUT_OFF);
 124                 break;
 125         case LED_FULL:
 126                 err = tlc591xx_set_ledout(priv, led, LEDOUT_ON);
 127                 break;
 128         default:
 129                 err = tlc591xx_set_ledout(priv, led, LEDOUT_DIM);
 130                 if (!err)
 131                         err = tlc591xx_set_pwm(priv, led, brightness);
 132         }
 133
 134         if (err)
 135                 dev_err(led->ldev.dev, "Failed setting brightness\n");
 136 }
 137
 138 static void
 139 tlc591xx_brightness_set(struct led_classdev *led_cdev,
 140                         enum led_brightness brightness)
 141 {
 142         struct tlc591xx_led *led = ldev_to_led(led_cdev);
 143
 144         led->ldev.brightness = brightness;
 145         schedule_work(&led->work);
 146 }
 147
 148 static void
 149 tlc591xx_destroy_devices(struct tlc591xx_priv *priv, unsigned int j)
 150 {
 151         int i = j;
 152
 153         while (--i >= 0) {
 154                 if (priv->leds[i].active) {
 155                         led_classdev_unregister(&priv->leds[i].ldev);
 156                         cancel_work_sync(&priv->leds[i].work);
 157                 }
 158         }
 159 }
 160
 161 static int
 162 tlc591xx_configure(struct device *dev,
 163                    struct tlc591xx_priv *priv,
 164                    const struct tlc591xx *tlc591xx)
 165 {
 166         unsigned int i;
 167         int err = 0;
 168
 169         tlc591xx_set_mode(priv->regmap, MODE2_DIM);
 170         for (i = 0; i < TLC591XX_MAX_LEDS; i++) {
 171                 struct tlc591xx_led *led = &priv->leds[i];
 172
 173                 if (!led->active)
 174                         continue;
 175
 176                 led->priv = priv;
 177                 led->led_no = i;
 178                 led->ldev.brightness_set = tlc591xx_brightness_set;
 179                 led->ldev.max_brightness = LED_FULL;
 180                 INIT_WORK(&led->work, tlc591xx_led_work);
 181                 err = led_classdev_register(dev, &led->ldev);
 182                 if (err < 0) {
 183                         dev_err(dev, "couldn't register LED %s\n",
 184                                 led->ldev.name);
 185                         goto exit;
 186                 }
 187         }
 188
 189         return 0;
 190
 191 exit:
 192         tlc591xx_destroy_devices(priv, i);
 193         return err;
 194 }
 195
 196 static const struct regmap_config tlc591xx_regmap = {
 197         .reg_bits = 8,
 198         .val_bits = 8,
 199         .max_register = 0x1e,
 200 };
 201
 202 static const struct of_device_id of_tlc591xx_leds_match[] = {
 203         { .compatible = "ti,tlc59116",
 204           .data = &tlc59116 },
 205         { .compatible = "ti,tlc59108",
 206           .data = &tlc59108 },
 207         {},
 208 };
 209 MODULE_DEVICE_TABLE(of, of_tlc591xx_leds_match);
 210
 211 static int
 212 tlc591xx_probe(struct i2c_client *client,
 213                const struct i2c_device_id *id)
 214 {
 215         struct device_node *np = client->dev.of_node, *child;
 216         struct device *dev = &client->dev;
 217         const struct of_device_id *match;
 218         const struct tlc591xx *tlc591xx;
 219         struct tlc591xx_priv *priv;
 220         int err, count, reg;
 221
 222         match = of_match_device(of_tlc591xx_leds_match, dev);
 223         if (!match)
 224                 return -ENODEV;
 225
 226         tlc591xx = match->data;
 227         if (!np)
 228                 return -ENODEV;
 229
 230         count = of_get_child_count(np);
 231         if (!count || count > tlc591xx->max_leds)
 232                 return -EINVAL;
 233
 234         if (!i2c_check_functionality(client->adapter,
 235                                      I2C_FUNC_SMBUS_BYTE_DATA))
 236                 return -EIO;
 237
 238         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 239         if (!priv)
 240                 return -ENOMEM;
 241
 242         priv->regmap = devm_regmap_init_i2c(client, &tlc591xx_regmap);
 243         if (IS_ERR(priv->regmap)) {
 244                 err = PTR_ERR(priv->regmap);
 245                 dev_err(dev, "Failed to allocate register map: %d\n", err);
 246                 return err;
 247         }
 248         priv->reg_ledout_offset = tlc591xx->reg_ledout_offset;
 249
 250         i2c_set_clientdata(client, priv);
 251
 252         for_each_child_of_node(np, child) {
 253                 err = of_property_read_u32(child, "reg", &reg);
 254                 if (err)
 255                         return err;
 256                 if (reg < 0 || reg >= tlc591xx->max_leds)
 257                         return -EINVAL;
 258                 if (priv->leds[reg].active)
 259                         return -EINVAL;
 260                 priv->leds[reg].active = true;
 261                 priv->leds[reg].ldev.name =
 262                         of_get_property(child, "label", NULL) ? : child->name;
 263                 priv->leds[reg].ldev.default_trigger =
 264                         of_get_property(child, "linux,default-trigger", NULL);
 265         }
 266         return tlc591xx_configure(dev, priv, tlc591xx);
 267 }
 268
 269 static int
 270 tlc591xx_remove(struct i2c_client *client)
 271 {
 272         struct tlc591xx_priv *priv = i2c_get_clientdata(client);
 273
 274         tlc591xx_destroy_devices(priv, TLC591XX_MAX_LEDS);
 275
 276         return 0;
 277 }
 278
 279 static const struct i2c_device_id tlc591xx_id[] = {
 280         { "tlc59116" },
 281         { "tlc59108" },
 282         {},
 283 };
 284 MODULE_DEVICE_TABLE(i2c, tlc591xx_id);
 285
 286 static struct i2c_driver tlc591xx_driver = {
 287         .driver = {
 288                 .name = "tlc591xx",
 289                 .of_match_table = of_match_ptr(of_tlc591xx_leds_match),
 290         },
 291         .probe = tlc591xx_probe,
 292         .remove = tlc591xx_remove,
 293         .id_table = tlc591xx_id,
 294 };
 295
 296 module_i2c_driver(tlc591xx_driver);
 297
 298 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
 299 MODULE_LICENSE("GPL");
 300 MODULE_DESCRIPTION("TLC591XX LED driver");