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