drivers/leds/leds-tlc591xx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2014 Belkin Inc.
   4  * Copyright 2015 Andrew Lunn <andrew@lunn.ch>
   5  */
   6
   7 #include <linux/i2c.h>
   8 #include <linux/leds.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/of_device.h>
  12 #include <linux/regmap.h>
  13 #include <linux/slab.h>
  14
  15 #define TLC591XX_MAX_LEDS       16
  16 #define TLC591XX_MAX_BRIGHTNESS 256
  17
  18 #define TLC591XX_REG_MODE1      0x00
  19 #define MODE1_RESPON_ADDR_MASK  0xF0
  20 #define MODE1_NORMAL_MODE       (0 << 4)
  21 #define MODE1_SPEED_MODE        (1 << 4)
  22
  23 #define TLC591XX_REG_MODE2      0x01
  24 #define MODE2_DIM               (0 << 5)
  25 #define MODE2_BLINK             (1 << 5)
  26 #define MODE2_OCH_STOP          (0 << 3)
  27 #define MODE2_OCH_ACK           (1 << 3)
  28
  29 #define TLC591XX_REG_PWM(x)     (0x02 + (x))
  30
  31 #define TLC591XX_REG_GRPPWM     0x12
  32 #define TLC591XX_REG_GRPFREQ    0x13
  33
  34 /* LED Driver Output State, determine the source that drives LED outputs */
  35 #define LEDOUT_OFF              0x0     /* Output LOW */
  36 #define LEDOUT_ON               0x1     /* Output HI-Z */
  37 #define LEDOUT_DIM              0x2     /* Dimming */
  38 #define LEDOUT_BLINK            0x3     /* Blinking */
  39 #define LEDOUT_MASK             0x3
  40
  41 #define ldev_to_led(c)          container_of(c, struct tlc591xx_led, ldev)
  42
  43 struct tlc591xx_led {
  44         bool active;
  45         unsigned int led_no;
  46         struct led_classdev ldev;
  47         struct tlc591xx_priv *priv;
  48 };
  49
  50 struct tlc591xx_priv {
  51         struct tlc591xx_led leds[TLC591XX_MAX_LEDS];
  52         struct regmap *regmap;
  53         unsigned int reg_ledout_offset;
  54 };
  55
  56 struct tlc591xx {
  57         unsigned int max_leds;
  58         unsigned int reg_ledout_offset;
  59 };
  60
  61 static const struct tlc591xx tlc59116 = {
  62         .max_leds = 16,
  63         .reg_ledout_offset = 0x14,
  64 };
  65
  66 static const struct tlc591xx tlc59108 = {
  67         .max_leds = 8,
  68         .reg_ledout_offset = 0x0c,
  69 };
  70
  71 static int
  72 tlc591xx_set_mode(struct regmap *regmap, u8 mode)
  73 {
  74         int err;
  75         u8 val;
  76
  77         err = regmap_write(regmap, TLC591XX_REG_MODE1, MODE1_NORMAL_MODE);
  78         if (err)
  79                 return err;
  80
  81         val = MODE2_OCH_STOP | mode;
  82
  83         return regmap_write(regmap, TLC591XX_REG_MODE2, val);
  84 }
  85
  86 static int
  87 tlc591xx_set_ledout(struct tlc591xx_priv *priv, struct tlc591xx_led *led,
  88                     u8 val)
  89 {
  90         unsigned int i = (led->led_no % 4) * 2;
  91         unsigned int mask = LEDOUT_MASK << i;
  92         unsigned int addr = priv->reg_ledout_offset + (led->led_no >> 2);
  93
  94         val = val << i;
  95
  96         return regmap_update_bits(priv->regmap, addr, mask, val);
  97 }
  98
  99 static int
 100 tlc591xx_set_pwm(struct tlc591xx_priv *priv, struct tlc591xx_led *led,
 101                  u8 brightness)
 102 {
 103         u8 pwm = TLC591XX_REG_PWM(led->led_no);
 104
 105         return regmap_write(priv->regmap, pwm, brightness);
 106 }
 107
 108 static int
 109 tlc591xx_brightness_set(struct led_classdev *led_cdev,
 110                         enum led_brightness brightness)
 111 {
 112         struct tlc591xx_led *led = ldev_to_led(led_cdev);
 113         struct tlc591xx_priv *priv = led->priv;
 114         int err;
 115
 116         switch ((int)brightness) {
 117         case 0:
 118                 err = tlc591xx_set_ledout(priv, led, LEDOUT_OFF);
 119                 break;
 120         case TLC591XX_MAX_BRIGHTNESS:
 121                 err = tlc591xx_set_ledout(priv, led, LEDOUT_ON);
 122                 break;
 123         default:
 124                 err = tlc591xx_set_ledout(priv, led, LEDOUT_DIM);
 125                 if (!err)
 126                         err = tlc591xx_set_pwm(priv, led, brightness);
 127         }
 128
 129         return err;
 130 }
 131
 132 static const struct regmap_config tlc591xx_regmap = {
 133         .reg_bits = 8,
 134         .val_bits = 8,
 135         .max_register = 0x1e,
 136 };
 137
 138 static const struct of_device_id of_tlc591xx_leds_match[] = {
 139         { .compatible = "ti,tlc59116",
 140           .data = &tlc59116 },
 141         { .compatible = "ti,tlc59108",
 142           .data = &tlc59108 },
 143         {},
 144 };
 145 MODULE_DEVICE_TABLE(of, of_tlc591xx_leds_match);
 146
 147 static int
 148 tlc591xx_probe(struct i2c_client *client,
 149                const struct i2c_device_id *id)
 150 {
 151         struct device_node *np, *child;
 152         struct device *dev = &client->dev;
 153         const struct tlc591xx *tlc591xx;
 154         struct tlc591xx_priv *priv;
 155         int err, count, reg;
 156
 157         np = dev_of_node(dev);
 158         if (!np)
 159                 return -ENODEV;
 160
 161         tlc591xx = device_get_match_data(dev);
 162         if (!tlc591xx)
 163                 return -ENODEV;
 164
 165         count = of_get_available_child_count(np);
 166         if (!count || count > tlc591xx->max_leds)
 167                 return -EINVAL;
 168
 169         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 170         if (!priv)
 171                 return -ENOMEM;
 172
 173         priv->regmap = devm_regmap_init_i2c(client, &tlc591xx_regmap);
 174         if (IS_ERR(priv->regmap)) {
 175                 err = PTR_ERR(priv->regmap);
 176                 dev_err(dev, "Failed to allocate register map: %d\n", err);
 177                 return err;
 178         }
 179         priv->reg_ledout_offset = tlc591xx->reg_ledout_offset;
 180
 181         i2c_set_clientdata(client, priv);
 182
 183         err = tlc591xx_set_mode(priv->regmap, MODE2_DIM);
 184         if (err < 0)
 185                 return err;
 186
 187         for_each_available_child_of_node(np, child) {
 188                 struct tlc591xx_led *led;
 189                 struct led_init_data init_data = {};
 190
 191                 init_data.fwnode = of_fwnode_handle(child);
 192
 193                 err = of_property_read_u32(child, "reg", &reg);
 194                 if (err) {
 195                         of_node_put(child);
 196                         return err;
 197                 }
 198                 if (reg < 0 || reg >= tlc591xx->max_leds ||
 199                     priv->leds[reg].active) {
 200                         of_node_put(child);
 201                         return -EINVAL;
 202                 }
 203                 led = &priv->leds[reg];
 204
 205                 led->active = true;
 206                 led->priv = priv;
 207                 led->led_no = reg;
 208                 led->ldev.brightness_set_blocking = tlc591xx_brightness_set;
 209                 led->ldev.max_brightness = TLC591XX_MAX_BRIGHTNESS;
 210                 err = devm_led_classdev_register_ext(dev, &led->ldev,
 211                                                      &init_data);
 212                 if (err < 0) {
 213                         of_node_put(child);
 214                         return dev_err_probe(dev, err,
 215                                              "couldn't register LED %s\n",
 216                                              led->ldev.name);
 217                 }
 218         }
 219         return 0;
 220 }
 221
 222 static const struct i2c_device_id tlc591xx_id[] = {
 223         { "tlc59116" },
 224         { "tlc59108" },
 225         {},
 226 };
 227 MODULE_DEVICE_TABLE(i2c, tlc591xx_id);
 228
 229 static struct i2c_driver tlc591xx_driver = {
 230         .driver = {
 231                 .name = "tlc591xx",
 232                 .of_match_table = of_match_ptr(of_tlc591xx_leds_match),
 233         },
 234         .probe = tlc591xx_probe,
 235         .id_table = tlc591xx_id,
 236 };
 237
 238 module_i2c_driver(tlc591xx_driver);
 239
 240 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
 241 MODULE_LICENSE("GPL");
 242 MODULE_DESCRIPTION("TLC591XX LED driver");