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