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