drivers/leds/leds-lp3952.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *      LED driver for TI lp3952 controller
   4  *
   5  *      Copyright (C) 2016, DAQRI, LLC.
   6  *      Author: Tony Makkiel <tony.makkiel@daqri.com>
   7  */
   8
   9 #include <linux/delay.h>
  10 #include <linux/gpio/consumer.h>
  11 #include <linux/i2c.h>
  12 #include <linux/io.h>
  13 #include <linux/kernel.h>
  14 #include <linux/leds.h>
  15 #include <linux/leds-lp3952.h>
  16 #include <linux/module.h>
  17 #include <linux/notifier.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/pm.h>
  20 #include <linux/reboot.h>
  21 #include <linux/regmap.h>
  22
  23 static int lp3952_register_write(struct i2c_client *client, u8 reg, u8 val)
  24 {
  25         int ret;
  26         struct lp3952_led_array *priv = i2c_get_clientdata(client);
  27
  28         ret = regmap_write(priv->regmap, reg, val);
  29
  30         if (ret)
  31                 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
  32                         __func__, reg, val, ret);
  33         return ret;
  34 }
  35
  36 static void lp3952_on_off(struct lp3952_led_array *priv,
  37                           enum lp3952_leds led_id, bool on)
  38 {
  39         int ret, val;
  40
  41         dev_dbg(&priv->client->dev, "%s LED %d to %d\n", __func__, led_id, on);
  42
  43         val = 1 << led_id;
  44         if (led_id == LP3952_LED_ALL)
  45                 val = LP3952_LED_MASK_ALL;
  46
  47         ret = regmap_update_bits(priv->regmap, LP3952_REG_LED_CTRL, val,
  48                                  on ? val : 0);
  49         if (ret)
  50                 dev_err(&priv->client->dev, "%s, Error %d\n", __func__, ret);
  51 }
  52
  53 /*
  54  * Using Imax to control brightness. There are 4 possible
  55  * setting 25, 50, 75 and 100 % of Imax. Possible values are
  56  * values 0-4. 0 meaning turn off.
  57  */
  58 static int lp3952_set_brightness(struct led_classdev *cdev,
  59                                  enum led_brightness value)
  60 {
  61         unsigned int reg, shift_val;
  62         struct lp3952_ctrl_hdl *led = container_of(cdev,
  63                                                    struct lp3952_ctrl_hdl,
  64                                                    cdev);
  65         struct lp3952_led_array *priv = (struct lp3952_led_array *)led->priv;
  66
  67         dev_dbg(cdev->dev, "Brightness request: %d on %d\n", value,
  68                 led->channel);
  69
  70         if (value == LED_OFF) {
  71                 lp3952_on_off(priv, led->channel, false);
  72                 return 0;
  73         }
  74
  75         if (led->channel > LP3952_RED_1) {
  76                 dev_err(cdev->dev, " %s Invalid LED requested", __func__);
  77                 return -EINVAL;
  78         }
  79
  80         if (led->channel >= LP3952_BLUE_1) {
  81                 reg = LP3952_REG_RGB1_MAX_I_CTRL;
  82                 shift_val = (led->channel - LP3952_BLUE_1) * 2;
  83         } else {
  84                 reg = LP3952_REG_RGB2_MAX_I_CTRL;
  85                 shift_val = led->channel * 2;
  86         }
  87
  88         /* Enable the LED in case it is not enabled already */
  89         lp3952_on_off(priv, led->channel, true);
  90
  91         return regmap_update_bits(priv->regmap, reg, 3 << shift_val,
  92                                   --value << shift_val);
  93 }
  94
  95 static int lp3952_get_label(struct device *dev, const char *label, char *dest)
  96 {
  97         int ret;
  98         const char *str;
  99
 100         ret = device_property_read_string(dev, label, &str);
 101         if (ret)
 102                 return ret;
 103
 104         strncpy(dest, str, LP3952_LABEL_MAX_LEN);
 105         return 0;
 106 }
 107
 108 static int lp3952_register_led_classdev(struct lp3952_led_array *priv)
 109 {
 110         int i, acpi_ret, ret = -ENODEV;
 111         static const char *led_name_hdl[LP3952_LED_ALL] = {
 112                 "blue2",
 113                 "green2",
 114                 "red2",
 115                 "blue1",
 116                 "green1",
 117                 "red1"
 118         };
 119
 120         for (i = 0; i < LP3952_LED_ALL; i++) {
 121                 acpi_ret = lp3952_get_label(&priv->client->dev, led_name_hdl[i],
 122                                             priv->leds[i].name);
 123                 if (acpi_ret)
 124                         continue;
 125
 126                 priv->leds[i].cdev.name = priv->leds[i].name;
 127                 priv->leds[i].cdev.brightness = LED_OFF;
 128                 priv->leds[i].cdev.max_brightness = LP3952_BRIGHT_MAX;
 129                 priv->leds[i].cdev.brightness_set_blocking =
 130                                 lp3952_set_brightness;
 131                 priv->leds[i].channel = i;
 132                 priv->leds[i].priv = priv;
 133
 134                 ret = devm_led_classdev_register(&priv->client->dev,
 135                                                  &priv->leds[i].cdev);
 136                 if (ret < 0) {
 137                         dev_err(&priv->client->dev,
 138                                 "couldn't register LED %s\n",
 139                                 priv->leds[i].cdev.name);
 140                         break;
 141                 }
 142         }
 143         return ret;
 144 }
 145
 146 static int lp3952_set_pattern_gen_cmd(struct lp3952_led_array *priv,
 147                                       u8 cmd_index, u8 r, u8 g, u8 b,
 148                                       enum lp3952_tt tt, enum lp3952_cet cet)
 149 {
 150         int ret;
 151         struct ptrn_gen_cmd line = {
 152                 {
 153                         {
 154                                 .r = r,
 155                                 .g = g,
 156                                 .b = b,
 157                                 .cet = cet,
 158                                 .tt = tt
 159                         }
 160                 }
 161         };
 162
 163         if (cmd_index >= LP3952_CMD_REG_COUNT)
 164                 return -EINVAL;
 165
 166         ret = lp3952_register_write(priv->client,
 167                                     LP3952_REG_CMD_0 + cmd_index * 2,
 168                                     line.bytes.msb);
 169         if (ret)
 170                 return ret;
 171
 172         return lp3952_register_write(priv->client,
 173                                       LP3952_REG_CMD_0 + cmd_index * 2 + 1,
 174                                       line.bytes.lsb);
 175 }
 176
 177 static int lp3952_configure(struct lp3952_led_array *priv)
 178 {
 179         int ret;
 180
 181         /* Disable any LEDs on from any previous conf. */
 182         ret = lp3952_register_write(priv->client, LP3952_REG_LED_CTRL, 0);
 183         if (ret)
 184                 return ret;
 185
 186         /* enable rgb patter, loop */
 187         ret = lp3952_register_write(priv->client, LP3952_REG_PAT_GEN_CTRL,
 188                                     LP3952_PATRN_LOOP | LP3952_PATRN_GEN_EN);
 189         if (ret)
 190                 return ret;
 191
 192         /* Update Bit 6 (Active mode), Select both Led sets, Bit [1:0] */
 193         ret = lp3952_register_write(priv->client, LP3952_REG_ENABLES,
 194                                     LP3952_ACTIVE_MODE | LP3952_INT_B00ST_LDR);
 195         if (ret)
 196                 return ret;
 197
 198         /* Set Cmd1 for RGB intensity,cmd and transition time */
 199         return lp3952_set_pattern_gen_cmd(priv, 0, I46, I71, I100, TT0,
 200                                            CET197);
 201 }
 202
 203 static const struct regmap_config lp3952_regmap = {
 204         .reg_bits = 8,
 205         .val_bits = 8,
 206         .max_register = REG_MAX,
 207         .cache_type = REGCACHE_RBTREE,
 208 };
 209
 210 static int lp3952_probe(struct i2c_client *client,
 211                         const struct i2c_device_id *id)
 212 {
 213         int status;
 214         struct lp3952_led_array *priv;
 215
 216         priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
 217         if (!priv)
 218                 return -ENOMEM;
 219
 220         priv->client = client;
 221
 222         priv->enable_gpio = devm_gpiod_get(&client->dev, "nrst",
 223                                            GPIOD_OUT_HIGH);
 224         if (IS_ERR(priv->enable_gpio)) {
 225                 status = PTR_ERR(priv->enable_gpio);
 226                 dev_err(&client->dev, "Failed to enable gpio: %d\n", status);
 227                 return status;
 228         }
 229
 230         priv->regmap = devm_regmap_init_i2c(client, &lp3952_regmap);
 231         if (IS_ERR(priv->regmap)) {
 232                 int err = PTR_ERR(priv->regmap);
 233
 234                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 235                         err);
 236                 return err;
 237         }
 238
 239         i2c_set_clientdata(client, priv);
 240
 241         status = lp3952_configure(priv);
 242         if (status) {
 243                 dev_err(&client->dev, "Probe failed. Device not found (%d)\n",
 244                         status);
 245                 return status;
 246         }
 247
 248         status = lp3952_register_led_classdev(priv);
 249         if (status) {
 250                 dev_err(&client->dev, "Unable to register led_classdev: %d\n",
 251                         status);
 252                 return status;
 253         }
 254
 255         return 0;
 256 }
 257
 258 static int lp3952_remove(struct i2c_client *client)
 259 {
 260         struct lp3952_led_array *priv;
 261
 262         priv = i2c_get_clientdata(client);
 263         lp3952_on_off(priv, LP3952_LED_ALL, false);
 264         gpiod_set_value(priv->enable_gpio, 0);
 265
 266         return 0;
 267 }
 268
 269 static const struct i2c_device_id lp3952_id[] = {
 270         {LP3952_NAME, 0},
 271         {}
 272 };
 273 MODULE_DEVICE_TABLE(i2c, lp3952_id);
 274
 275 static struct i2c_driver lp3952_i2c_driver = {
 276         .driver = {
 277                         .name = LP3952_NAME,
 278         },
 279         .probe = lp3952_probe,
 280         .remove = lp3952_remove,
 281         .id_table = lp3952_id,
 282 };
 283
 284 module_i2c_driver(lp3952_i2c_driver);
 285
 286 MODULE_AUTHOR("Tony Makkiel <tony.makkiel@daqri.com>");
 287 MODULE_DESCRIPTION("lp3952 I2C LED controller driver");
 288 MODULE_LICENSE("GPL v2");