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