drivers/leds/leds-pca995x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * LED driver for PCA995x I2C LED drivers
   4  *
   5  * Copyright 2011 bct electronic GmbH
   6  * Copyright 2013 Qtechnology/AS
   7  * Copyright 2022 NXP
   8  * Copyright 2023 Marek Vasut
   9  */
  10
  11 #include <linux/i2c.h>
  12 #include <linux/leds.h>
  13 #include <linux/module.h>
  14 #include <linux/mod_devicetable.h>
  15 #include <linux/property.h>
  16 #include <linux/regmap.h>
  17
  18 /* Register definition */
  19 #define PCA995X_MODE1                   0x00
  20 #define PCA995X_MODE2                   0x01
  21 #define PCA995X_LEDOUT0                 0x02
  22
  23 /* Auto-increment disabled. Normal mode */
  24 #define PCA995X_MODE1_CFG               0x00
  25
  26 /* LED select registers determine the source that drives LED outputs */
  27 #define PCA995X_LED_OFF                 0x0
  28 #define PCA995X_LED_ON                  0x1
  29 #define PCA995X_LED_PWM_MODE            0x2
  30 #define PCA995X_LDRX_MASK               0x3
  31 #define PCA995X_LDRX_BITS               2
  32
  33 #define PCA995X_MAX_OUTPUTS             24
  34 #define PCA995X_OUTPUTS_PER_REG         4
  35
  36 #define PCA995X_IREFALL_FULL_CFG        0xFF
  37 #define PCA995X_IREFALL_HALF_CFG        (PCA995X_IREFALL_FULL_CFG / 2)
  38
  39 #define ldev_to_led(c)  container_of(c, struct pca995x_led, ldev)
  40
  41 struct pca995x_chipdef {
  42         unsigned int num_leds;
  43         u8 pwm_base;
  44         u8 irefall;
  45 };
  46
  47 static const struct pca995x_chipdef pca9952_chipdef = {
  48         .num_leds       = 16,
  49         .pwm_base       = 0x0a,
  50         .irefall        = 0x43,
  51 };
  52
  53 static const struct pca995x_chipdef pca9955b_chipdef = {
  54         .num_leds       = 16,
  55         .pwm_base       = 0x08,
  56         .irefall        = 0x45,
  57 };
  58
  59 static const struct pca995x_chipdef pca9956b_chipdef = {
  60         .num_leds       = 24,
  61         .pwm_base       = 0x0a,
  62         .irefall        = 0x40,
  63 };
  64
  65 struct pca995x_led {
  66         unsigned int led_no;
  67         struct led_classdev ldev;
  68         struct pca995x_chip *chip;
  69 };
  70
  71 struct pca995x_chip {
  72         struct regmap *regmap;
  73         struct pca995x_led leds[PCA995X_MAX_OUTPUTS];
  74         const struct pca995x_chipdef *chipdef;
  75 };
  76
  77 static int pca995x_brightness_set(struct led_classdev *led_cdev,
  78                                   enum led_brightness brightness)
  79 {
  80         struct pca995x_led *led = ldev_to_led(led_cdev);
  81         struct pca995x_chip *chip = led->chip;
  82         const struct pca995x_chipdef *chipdef = chip->chipdef;
  83         u8 ledout_addr, pwmout_addr;
  84         int shift, ret;
  85
  86         pwmout_addr = chipdef->pwm_base + led->led_no;
  87         ledout_addr = PCA995X_LEDOUT0 + (led->led_no / PCA995X_OUTPUTS_PER_REG);
  88         shift = PCA995X_LDRX_BITS * (led->led_no % PCA995X_OUTPUTS_PER_REG);
  89
  90         switch (brightness) {
  91         case LED_FULL:
  92                 return regmap_update_bits(chip->regmap, ledout_addr,
  93                                           PCA995X_LDRX_MASK << shift,
  94                                           PCA995X_LED_ON << shift);
  95         case LED_OFF:
  96                 return regmap_update_bits(chip->regmap, ledout_addr,
  97                                           PCA995X_LDRX_MASK << shift, 0);
  98         default:
  99                 /* Adjust brightness as per user input by changing individual PWM */
 100                 ret = regmap_write(chip->regmap, pwmout_addr, brightness);
 101                 if (ret)
 102                         return ret;
 103
 104                 /*
 105                  * Change LDRx configuration to individual brightness via PWM.
 106                  * LED will stop blinking if it's doing so.
 107                  */
 108                 return regmap_update_bits(chip->regmap, ledout_addr,
 109                                           PCA995X_LDRX_MASK << shift,
 110                                           PCA995X_LED_PWM_MODE << shift);
 111         }
 112 }
 113
 114 static const struct regmap_config pca995x_regmap = {
 115         .reg_bits = 8,
 116         .val_bits = 8,
 117         .max_register = 0x49,
 118 };
 119
 120 static int pca995x_probe(struct i2c_client *client)
 121 {
 122         struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 };
 123         struct device *dev = &client->dev;
 124         const struct pca995x_chipdef *chipdef;
 125         struct pca995x_chip *chip;
 126         struct pca995x_led *led;
 127         int i, j, reg, ret;
 128
 129         chipdef = device_get_match_data(&client->dev);
 130
 131         if (!dev_fwnode(dev))
 132                 return -ENODEV;
 133
 134         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 135         if (!chip)
 136                 return -ENOMEM;
 137
 138         chip->chipdef = chipdef;
 139         chip->regmap = devm_regmap_init_i2c(client, &pca995x_regmap);
 140         if (IS_ERR(chip->regmap))
 141                 return PTR_ERR(chip->regmap);
 142
 143         i2c_set_clientdata(client, chip);
 144
 145         device_for_each_child_node_scoped(dev, child) {
 146                 ret = fwnode_property_read_u32(child, "reg", &reg);
 147                 if (ret)
 148                         return ret;
 149
 150                 if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg])
 151                         return -EINVAL;
 152
 153                 led = &chip->leds[reg];
 154                 led_fwnodes[reg] = fwnode_handle_get(child);
 155                 led->chip = chip;
 156                 led->led_no = reg;
 157                 led->ldev.brightness_set_blocking = pca995x_brightness_set;
 158                 led->ldev.max_brightness = 255;
 159         }
 160
 161         for (i = 0; i < PCA995X_MAX_OUTPUTS; i++) {
 162                 struct led_init_data init_data = {};
 163
 164                 if (!led_fwnodes[i])
 165                         continue;
 166
 167                 init_data.fwnode = led_fwnodes[i];
 168
 169                 ret = devm_led_classdev_register_ext(dev,
 170                                                      &chip->leds[i].ldev,
 171                                                      &init_data);
 172                 if (ret < 0) {
 173                         for (j = i; j < PCA995X_MAX_OUTPUTS; j++)
 174                                 fwnode_handle_put(led_fwnodes[j]);
 175                         return dev_err_probe(dev, ret,
 176                                              "Could not register LED %s\n",
 177                                              chip->leds[i].ldev.name);
 178                 }
 179         }
 180
 181         /* Disable LED all-call address and set normal mode */
 182         ret = regmap_write(chip->regmap, PCA995X_MODE1, PCA995X_MODE1_CFG);
 183         if (ret)
 184                 return ret;
 185
 186         /* IREF Output current value for all LEDn outputs */
 187         return regmap_write(chip->regmap, chipdef->irefall, PCA995X_IREFALL_HALF_CFG);
 188 }
 189
 190 static const struct i2c_device_id pca995x_id[] = {
 191         { "pca9952", .driver_data = (kernel_ulong_t)&pca9952_chipdef },
 192         { "pca9955b", .driver_data = (kernel_ulong_t)&pca9955b_chipdef },
 193         { "pca9956b", .driver_data = (kernel_ulong_t)&pca9956b_chipdef },
 194         {}
 195 };
 196 MODULE_DEVICE_TABLE(i2c, pca995x_id);
 197
 198 static const struct of_device_id pca995x_of_match[] = {
 199         { .compatible = "nxp,pca9952", .data = &pca9952_chipdef },
 200         { .compatible = "nxp,pca9955b", . data = &pca9955b_chipdef },
 201         { .compatible = "nxp,pca9956b", .data = &pca9956b_chipdef },
 202         {},
 203 };
 204 MODULE_DEVICE_TABLE(of, pca995x_of_match);
 205
 206 static struct i2c_driver pca995x_driver = {
 207         .driver = {
 208                 .name = "leds-pca995x",
 209                 .of_match_table = pca995x_of_match,
 210         },
 211         .probe = pca995x_probe,
 212         .id_table = pca995x_id,
 213 };
 214 module_i2c_driver(pca995x_driver);
 215
 216 MODULE_AUTHOR("Isai Gaspar <[email protected]>");
 217 MODULE_DESCRIPTION("PCA995x LED driver");
 218 MODULE_LICENSE("GPL");