target/linux/ath79/patches-5.4/0003-leds-add-reset-controller-based-driver.patch

   1 From ecbd9c87f073f097d9fe56390353e64e963e866a Mon Sep 17 00:00:00 2001
   2 From: John Crispin <john@phrozen.org>
   3 Date: Tue, 6 Mar 2018 10:03:03 +0100
   4 Subject: [PATCH 03/27] leds: add reset-controller based driver
   5
   6 Signed-off-by: John Crispin <john@phrozen.org>
   7 ---
   8  drivers/leds/Kconfig      |  11 ++++
   9  drivers/leds/Makefile     |   1 +
  10  drivers/leds/leds-reset.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++
  11  3 files changed, 149 insertions(+)
  12  create mode 100644 drivers/leds/leds-reset.c
  13
  14 --- a/drivers/leds/Kconfig
  15 +++ b/drivers/leds/Kconfig
  16 @@ -823,6 +823,17 @@ config LEDS_LM36274
  17           Say Y to enable the LM36274 LED driver for TI LMU devices.
  18           This supports the LED device LM36274.
  19
  20 +config LEDS_RESET
  21 +       tristate "LED support for reset-controller API"
  22 +       depends on LEDS_CLASS
  23 +       depends on RESET_CONTROLLER
  24 +       help
  25 +         This option enables support for LEDs connected to pins driven by reset
  26 +         controllers. Yes, DNI actual built HW like that.
  27 +
  28 +         To compile this driver as a module, choose M here: the module
  29 +         will be called leds-reset.
  30 +
  31  comment "LED Triggers"
  32  source "drivers/leds/trigger/Kconfig"
  33
  34 --- /dev/null
  35 +++ b/drivers/leds/leds-reset.c
  36 @@ -0,0 +1,140 @@
  37 +/*
  38 + * Copyright (C) 2018 John Crispin <john@phrozen.org>
  39 + *
  40 + * This program is free software; you can redistribute it and/or modify
  41 + * it under the terms of the GNU General Public License version 2 as
  42 + * published by the Free Software Foundation.
  43 + *
  44 + */
  45 +#include <linux/err.h>
  46 +#include <linux/reset.h>
  47 +#include <linux/kernel.h>
  48 +#include <linux/leds.h>
  49 +#include <linux/module.h>
  50 +#include <linux/of.h>
  51 +#include <linux/platform_device.h>
  52 +#include <linux/reset.h>
  53 +
  54 +struct reset_led_data {
  55 +       struct led_classdev cdev;
  56 +       struct reset_control *rst;
  57 +};
  58 +
  59 +static inline struct reset_led_data *
  60 +                       cdev_to_reset_led_data(struct led_classdev *led_cdev)
  61 +{
  62 +       return container_of(led_cdev, struct reset_led_data, cdev);
  63 +}
  64 +
  65 +static void reset_led_set(struct led_classdev *led_cdev,
  66 +       enum led_brightness value)
  67 +{
  68 +       struct reset_led_data *led_dat = cdev_to_reset_led_data(led_cdev);
  69 +
  70 +       if (value == LED_OFF)
  71 +               reset_control_assert(led_dat->rst);
  72 +       else
  73 +               reset_control_deassert(led_dat->rst);
  74 +}
  75 +
  76 +struct reset_leds_priv {
  77 +       int num_leds;
  78 +       struct reset_led_data leds[];
  79 +};
  80 +
  81 +static inline int sizeof_reset_leds_priv(int num_leds)
  82 +{
  83 +       return sizeof(struct reset_leds_priv) +
  84 +               (sizeof(struct reset_led_data) * num_leds);
  85 +}
  86 +
  87 +static struct reset_leds_priv *reset_leds_create(struct platform_device *pdev)
  88 +{
  89 +       struct device *dev = &pdev->dev;
  90 +       struct fwnode_handle *child;
  91 +       struct reset_leds_priv *priv;
  92 +       int count, ret;
  93 +
  94 +       count = device_get_child_node_count(dev);
  95 +       if (!count)
  96 +               return ERR_PTR(-ENODEV);
  97 +
  98 +       priv = devm_kzalloc(dev, sizeof_reset_leds_priv(count), GFP_KERNEL);
  99 +       if (!priv)
 100 +               return ERR_PTR(-ENOMEM);
 101 +
 102 +       device_for_each_child_node(dev, child) {
 103 +               struct reset_led_data *led = &priv->leds[priv->num_leds];
 104 +               struct device_node *np = to_of_node(child);
 105 +
 106 +               ret = fwnode_property_read_string(child, "label", &led->cdev.name);
 107 +               if (!led->cdev.name) {
 108 +                       fwnode_handle_put(child);
 109 +                       return ERR_PTR(-EINVAL);
 110 +               }
 111 +               led->rst = __of_reset_control_get(np, NULL, 0, 0, 0, true);
 112 +               if (IS_ERR(led->rst))
 113 +                       return ERR_PTR(-EINVAL);
 114 +
 115 +               fwnode_property_read_string(child, "linux,default-trigger",
 116 +                                               &led->cdev.default_trigger);
 117 +
 118 +               led->cdev.brightness_set = reset_led_set;
 119 +               ret = devm_led_classdev_register(&pdev->dev, &led->cdev);
 120 +               if (ret < 0)
 121 +                       return ERR_PTR(ret);
 122 +               led->cdev.dev->of_node = np;
 123 +               priv->num_leds++;
 124 +       }
 125 +
 126 +       return priv;
 127 +}
 128 +
 129 +static const struct of_device_id of_reset_leds_match[] = {
 130 +       { .compatible = "reset-leds", },
 131 +       {},
 132 +};
 133 +
 134 +MODULE_DEVICE_TABLE(of, of_reset_leds_match);
 135 +
 136 +static int reset_led_probe(struct platform_device *pdev)
 137 +{
 138 +       struct reset_leds_priv *priv;
 139 +
 140 +       priv = reset_leds_create(pdev);
 141 +       if (IS_ERR(priv))
 142 +               return PTR_ERR(priv);
 143 +
 144 +       platform_set_drvdata(pdev, priv);
 145 +
 146 +       return 0;
 147 +}
 148 +
 149 +static void reset_led_shutdown(struct platform_device *pdev)
 150 +{
 151 +       struct reset_leds_priv *priv = platform_get_drvdata(pdev);
 152 +       int i;
 153 +
 154 +       for (i = 0; i < priv->num_leds; i++) {
 155 +               struct reset_led_data *led = &priv->leds[i];
 156 +
 157 +               if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
 158 +                       reset_led_set(&led->cdev, LED_OFF);
 159 +       }
 160 +}
 161 +
 162 +static struct platform_driver reset_led_driver = {
 163 +       .probe          = reset_led_probe,
 164 +       .shutdown       = reset_led_shutdown,
 165 +       .driver         = {
 166 +               .name   = "leds-reset",
 167 +               .of_match_table = of_reset_leds_match,
 168 +       },
 169 +};
 170 +
 171 +module_platform_driver(reset_led_driver);
 172 +
 173 +MODULE_AUTHOR("John Crispin <john@phrozen.org>");
 174 +MODULE_DESCRIPTION("reset controller LED driver");
 175 +MODULE_LICENSE("GPL");
 176 +MODULE_ALIAS("platform:leds-reset");
 177 --- a/drivers/leds/Makefile
 178 +++ b/drivers/leds/Makefile
 179 @@ -85,6 +85,7 @@ obj-$(CONFIG_LEDS_LM3601X)            += leds-lm36
 180  obj-$(CONFIG_LEDS_TI_LMU_COMMON)       += leds-ti-lmu-common.o
 181  obj-$(CONFIG_LEDS_LM3697)              += leds-lm3697.o
 182  obj-$(CONFIG_LEDS_LM36274)             += leds-lm36274.o
 183 +obj-$(CONFIG_LEDS_RESET)               += leds-reset.o
 184
 185  # LED SPI Drivers
 186  obj-$(CONFIG_LEDS_CR0014114)           += leds-cr0014114.o