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