drivers/leds/leds-gpio.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * LEDs driver for GPIOs
   4  *
   5  * Copyright (C) 2007 8D Technologies inc.
   6  * Raphael Assenat <raph@8d.com>
   7  * Copyright (C) 2008 Freescale Semiconductor, Inc.
   8  */
   9 #include <linux/container_of.h>
  10 #include <linux/device.h>
  11 #include <linux/err.h>
  12 #include <linux/gpio.h>
  13 #include <linux/gpio/consumer.h>
  14 #include <linux/leds.h>
  15 #include <linux/mod_devicetable.h>
  16 #include <linux/module.h>
  17 #include <linux/overflow.h>
  18 #include <linux/pinctrl/consumer.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/property.h>
  21 #include <linux/slab.h>
  22 #include <linux/types.h>
  23
  24 #include "leds.h"
  25
  26 struct gpio_led_data {
  27         struct led_classdev cdev;
  28         struct gpio_desc *gpiod;
  29         u8 can_sleep;
  30         u8 blinking;
  31         gpio_blink_set_t platform_gpio_blink_set;
  32 };
  33
  34 static inline struct gpio_led_data *
  35                         cdev_to_gpio_led_data(struct led_classdev *led_cdev)
  36 {
  37         return container_of(led_cdev, struct gpio_led_data, cdev);
  38 }
  39
  40 static void gpio_led_set(struct led_classdev *led_cdev,
  41         enum led_brightness value)
  42 {
  43         struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
  44         int level;
  45
  46         if (value == LED_OFF)
  47                 level = 0;
  48         else
  49                 level = 1;
  50
  51         if (led_dat->blinking) {
  52                 led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
  53                                                  NULL, NULL);
  54                 led_dat->blinking = 0;
  55         } else {
  56                 if (led_dat->can_sleep)
  57                         gpiod_set_value_cansleep(led_dat->gpiod, level);
  58                 else
  59                         gpiod_set_value(led_dat->gpiod, level);
  60         }
  61 }
  62
  63 static int gpio_led_set_blocking(struct led_classdev *led_cdev,
  64         enum led_brightness value)
  65 {
  66         gpio_led_set(led_cdev, value);
  67         return 0;
  68 }
  69
  70 static int gpio_blink_set(struct led_classdev *led_cdev,
  71         unsigned long *delay_on, unsigned long *delay_off)
  72 {
  73         struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);
  74
  75         led_dat->blinking = 1;
  76         return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,
  77                                                 delay_on, delay_off);
  78 }
  79
  80 static int create_gpio_led(const struct gpio_led *template,
  81         struct gpio_led_data *led_dat, struct device *parent,
  82         struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)
  83 {
  84         struct led_init_data init_data = {};
  85         struct pinctrl *pinctrl;
  86         int ret, state;
  87
  88         led_dat->cdev.default_trigger = template->default_trigger;
  89         led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);
  90         if (!led_dat->can_sleep)
  91                 led_dat->cdev.brightness_set = gpio_led_set;
  92         else
  93                 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;
  94         led_dat->blinking = 0;
  95         if (blink_set) {
  96                 led_dat->platform_gpio_blink_set = blink_set;
  97                 led_dat->cdev.blink_set = gpio_blink_set;
  98         }
  99         if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
 100                 state = gpiod_get_value_cansleep(led_dat->gpiod);
 101                 if (state < 0)
 102                         return state;
 103         } else {
 104                 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
 105         }
 106         led_dat->cdev.brightness = state;
 107         led_dat->cdev.max_brightness = 1;
 108         if (!template->retain_state_suspended)
 109                 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 110         if (template->panic_indicator)
 111                 led_dat->cdev.flags |= LED_PANIC_INDICATOR;
 112         if (template->retain_state_shutdown)
 113                 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;
 114
 115         ret = gpiod_direction_output(led_dat->gpiod, state);
 116         if (ret < 0)
 117                 return ret;
 118
 119         if (template->name) {
 120                 led_dat->cdev.name = template->name;
 121                 ret = devm_led_classdev_register(parent, &led_dat->cdev);
 122         } else {
 123                 init_data.fwnode = fwnode;
 124                 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
 125                                                      &init_data);
 126         }
 127
 128         if (ret)
 129                 return ret;
 130
 131         pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev);
 132         ret = PTR_ERR_OR_ZERO(pinctrl);
 133         /* pinctrl-%d not present, not an error */
 134         if (ret == -ENODEV)
 135                 ret = 0;
 136         if (ret) {
 137                 dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n",
 138                          fwnode, ret);
 139         }
 140
 141         return ret;
 142 }
 143
 144 struct gpio_leds_priv {
 145         int num_leds;
 146         struct gpio_led_data leds[] __counted_by(num_leds);
 147 };
 148
 149 static struct gpio_leds_priv *gpio_leds_create(struct device *dev)
 150 {
 151         struct fwnode_handle *child;
 152         struct gpio_leds_priv *priv;
 153         int count, used, ret;
 154
 155         count = device_get_child_node_count(dev);
 156         if (!count)
 157                 return ERR_PTR(-ENODEV);
 158
 159         priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
 160         if (!priv)
 161                 return ERR_PTR(-ENOMEM);
 162         priv->num_leds = count;
 163         used = 0;
 164
 165         device_for_each_child_node(dev, child) {
 166                 struct gpio_led_data *led_dat = &priv->leds[used];
 167                 struct gpio_led led = {};
 168
 169                 /*
 170                  * Acquire gpiod from DT with uninitialized label, which
 171                  * will be updated after LED class device is registered,
 172                  * Only then the final LED name is known.
 173                  */
 174                 led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS,
 175                                                   NULL);
 176                 if (IS_ERR(led.gpiod)) {
 177                         dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n",
 178                                       child);
 179                         fwnode_handle_put(child);
 180                         return ERR_CAST(led.gpiod);
 181                 }
 182
 183                 led_dat->gpiod = led.gpiod;
 184
 185                 led.default_state = led_init_default_state_get(child);
 186
 187                 if (fwnode_property_present(child, "retain-state-suspended"))
 188                         led.retain_state_suspended = 1;
 189                 if (fwnode_property_present(child, "retain-state-shutdown"))
 190                         led.retain_state_shutdown = 1;
 191                 if (fwnode_property_present(child, "panic-indicator"))
 192                         led.panic_indicator = 1;
 193
 194                 ret = create_gpio_led(&led, led_dat, dev, child, NULL);
 195                 if (ret < 0) {
 196                         fwnode_handle_put(child);
 197                         return ERR_PTR(ret);
 198                 }
 199                 /* Set gpiod label to match the corresponding LED name. */
 200                 gpiod_set_consumer_name(led_dat->gpiod,
 201                                         led_dat->cdev.dev->kobj.name);
 202                 used++;
 203         }
 204         priv->num_leds = used;
 205
 206         return priv;
 207 }
 208
 209 static const struct of_device_id of_gpio_leds_match[] = {
 210         { .compatible = "gpio-leds", },
 211         {},
 212 };
 213
 214 MODULE_DEVICE_TABLE(of, of_gpio_leds_match);
 215
 216 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
 217                                             const struct gpio_led *template)
 218 {
 219         struct gpio_desc *gpiod;
 220         unsigned long flags = GPIOF_OUT_INIT_LOW;
 221         int ret;
 222
 223         /*
 224          * This means the LED does not come from the device tree
 225          * or ACPI, so let's try just getting it by index from the
 226          * device, this will hit the board file, if any and get
 227          * the GPIO from there.
 228          */
 229         gpiod = devm_gpiod_get_index_optional(dev, NULL, idx, GPIOD_OUT_LOW);
 230         if (IS_ERR(gpiod))
 231                 return gpiod;
 232         if (gpiod) {
 233                 gpiod_set_consumer_name(gpiod, template->name);
 234                 return gpiod;
 235         }
 236
 237         /*
 238          * This is the legacy code path for platform code that
 239          * still uses GPIO numbers. Ultimately we would like to get
 240          * rid of this block completely.
 241          */
 242
 243         /* skip leds that aren't available */
 244         if (!gpio_is_valid(template->gpio))
 245                 return ERR_PTR(-ENOENT);
 246
 247         if (template->active_low)
 248                 flags |= GPIOF_ACTIVE_LOW;
 249
 250         ret = devm_gpio_request_one(dev, template->gpio, flags,
 251                                     template->name);
 252         if (ret < 0)
 253                 return ERR_PTR(ret);
 254
 255         gpiod = gpio_to_desc(template->gpio);
 256         if (!gpiod)
 257                 return ERR_PTR(-EINVAL);
 258
 259         return gpiod;
 260 }
 261
 262 static int gpio_led_probe(struct platform_device *pdev)
 263 {
 264         struct device *dev = &pdev->dev;
 265         struct gpio_led_platform_data *pdata = dev_get_platdata(dev);
 266         struct gpio_leds_priv *priv;
 267         int i, ret;
 268
 269         if (pdata && pdata->num_leds) {
 270                 priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL);
 271                 if (!priv)
 272                         return -ENOMEM;
 273
 274                 priv->num_leds = pdata->num_leds;
 275                 for (i = 0; i < priv->num_leds; i++) {
 276                         const struct gpio_led *template = &pdata->leds[i];
 277                         struct gpio_led_data *led_dat = &priv->leds[i];
 278
 279                         if (template->gpiod)
 280                                 led_dat->gpiod = template->gpiod;
 281                         else
 282                                 led_dat->gpiod =
 283                                         gpio_led_get_gpiod(dev, i, template);
 284                         if (IS_ERR(led_dat->gpiod)) {
 285                                 dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n",
 286                                          template->gpio, template->name);
 287                                 continue;
 288                         }
 289
 290                         ret = create_gpio_led(template, led_dat, dev, NULL,
 291                                               pdata->gpio_blink_set);
 292                         if (ret < 0)
 293                                 return ret;
 294                 }
 295         } else {
 296                 priv = gpio_leds_create(dev);
 297                 if (IS_ERR(priv))
 298                         return PTR_ERR(priv);
 299         }
 300
 301         platform_set_drvdata(pdev, priv);
 302
 303         return 0;
 304 }
 305
 306 static void gpio_led_shutdown(struct platform_device *pdev)
 307 {
 308         struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
 309         int i;
 310
 311         for (i = 0; i < priv->num_leds; i++) {
 312                 struct gpio_led_data *led = &priv->leds[i];
 313
 314                 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
 315                         gpio_led_set(&led->cdev, LED_OFF);
 316         }
 317 }
 318
 319 static struct platform_driver gpio_led_driver = {
 320         .probe          = gpio_led_probe,
 321         .shutdown       = gpio_led_shutdown,
 322         .driver         = {
 323                 .name   = "leds-gpio",
 324                 .of_match_table = of_gpio_leds_match,
 325         },
 326 };
 327
 328 module_platform_driver(gpio_led_driver);
 329
 330 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
 331 MODULE_DESCRIPTION("GPIO LED driver");
 332 MODULE_LICENSE("GPL");
 333 MODULE_ALIAS("platform:leds-gpio");