drivers/leds/leds-max5970.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Device driver for leds in MAX5970 and MAX5978 IC
   4  *
   5  * Copyright (c) 2022 9elements GmbH
   6  *
   7  * Author: Patrick Rudolph <[email protected]>
   8  */
   9
  10 #include <linux/bits.h>
  11 #include <linux/container_of.h>
  12 #include <linux/device.h>
  13 #include <linux/leds.h>
  14 #include <linux/mfd/max5970.h>
  15 #include <linux/mod_devicetable.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/property.h>
  19 #include <linux/regmap.h>
  20
  21 #define ldev_to_maxled(c)       container_of(c, struct max5970_led, cdev)
  22
  23 struct max5970_led {
  24         struct device *dev;
  25         struct regmap *regmap;
  26         struct led_classdev cdev;
  27         unsigned int index;
  28 };
  29
  30 static int max5970_led_set_brightness(struct led_classdev *cdev,
  31                                       enum led_brightness brightness)
  32 {
  33         struct max5970_led *ddata = ldev_to_maxled(cdev);
  34         int ret, val;
  35
  36         /* Set/clear corresponding bit for given led index */
  37         val = !brightness ? BIT(ddata->index) : 0;
  38
  39         ret = regmap_update_bits(ddata->regmap, MAX5970_REG_LED_FLASH, BIT(ddata->index), val);
  40         if (ret < 0)
  41                 dev_err(cdev->dev, "failed to set brightness %d", ret);
  42
  43         return ret;
  44 }
  45
  46 static int max5970_led_probe(struct platform_device *pdev)
  47 {
  48         struct fwnode_handle *child;
  49         struct device *dev = &pdev->dev;
  50         struct regmap *regmap;
  51         struct max5970_led *ddata;
  52         int ret = -ENODEV;
  53
  54         regmap = dev_get_regmap(dev->parent, NULL);
  55         if (!regmap)
  56                 return -ENODEV;
  57
  58         struct fwnode_handle *led_node __free(fwnode_handle) =
  59                 device_get_named_child_node(dev->parent, "leds");
  60         if (!led_node)
  61                 return -ENODEV;
  62
  63         fwnode_for_each_available_child_node(led_node, child) {
  64                 u32 reg;
  65
  66                 if (fwnode_property_read_u32(child, "reg", &reg))
  67                         continue;
  68
  69                 if (reg >= MAX5970_NUM_LEDS) {
  70                         dev_err_probe(dev, -EINVAL, "invalid LED (%u >= %d)\n", reg, MAX5970_NUM_LEDS);
  71                         continue;
  72                 }
  73
  74                 ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
  75                 if (!ddata) {
  76                         fwnode_handle_put(child);
  77                         return -ENOMEM;
  78                 }
  79
  80                 ddata->index = reg;
  81                 ddata->regmap = regmap;
  82                 ddata->dev = dev;
  83
  84                 if (fwnode_property_read_string(child, "label", &ddata->cdev.name))
  85                         ddata->cdev.name = fwnode_get_name(child);
  86
  87                 ddata->cdev.max_brightness = 1;
  88                 ddata->cdev.brightness_set_blocking = max5970_led_set_brightness;
  89                 ddata->cdev.default_trigger = "none";
  90
  91                 ret = devm_led_classdev_register(dev, &ddata->cdev);
  92                 if (ret < 0) {
  93                         fwnode_handle_put(child);
  94                         return dev_err_probe(dev, ret, "Failed to initialize LED %u\n", reg);
  95                 }
  96         }
  97
  98         return ret;
  99 }
 100
 101 static struct platform_driver max5970_led_driver = {
 102         .driver = {
 103                 .name = "max5970-led",
 104         },
 105         .probe = max5970_led_probe,
 106 };
 107 module_platform_driver(max5970_led_driver);
 108
 109 MODULE_AUTHOR("Patrick Rudolph <[email protected]>");
 110 MODULE_AUTHOR("Naresh Solanki <[email protected]>");
 111 MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
 112 MODULE_LICENSE("GPL");