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; 100 led_dat->cdev.max_brightness = 1; 101 if (!template->retain_state_suspended) 102 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 103 if (template->panic_indicator) 104 led_dat->cdev.flags |= LED_PANIC_INDICATOR; 105 if (template->retain_state_shutdown) 106 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN; 107 108 ret = gpiod_direction_output(led_dat->gpiod, state); 109 if (ret < 0) 110 return ret; 111 112 if (template->name) { 113 led_dat->cdev.name = template->name; 114 ret = devm_led_classdev_register(parent, &led_dat->cdev); 115 } else { 116 init_data.fwnode = fwnode; 117 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev, 118 &init_data); 119 } 120 121 return ret; 122 } 123 124 struct gpio_leds_priv { 125 int num_leds; 126 struct gpio_led_data leds[]; 127 }; 128 129 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev) 130 { 131 struct device *dev = &pdev->dev; 132 struct fwnode_handle *child; 133 struct gpio_leds_priv *priv; 134 int count, ret; 135 136 count = device_get_child_node_count(dev); 137 if (!count) 138 return ERR_PTR(-ENODEV); 139 140 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL); 141 if (!priv) 142 return ERR_PTR(-ENOMEM); 143 144 device_for_each_child_node(dev, child) { 145 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds]; 146 struct gpio_led led = {}; 147 const char *state = NULL; 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_get_gpiod_from_child(dev, NULL, child, 155 GPIOD_ASIS, 156 NULL); 157 if (IS_ERR(led.gpiod)) { 158 fwnode_handle_put(child); 159 return ERR_CAST(led.gpiod); 160 } 161 162 led_dat->gpiod = led.gpiod; 163 164 if (!fwnode_property_read_string(child, "default-state", 165 &state)) { 166 if (!strcmp(state, "keep")) 167 led.default_state = LEDS_GPIO_DEFSTATE_KEEP; 168 else if (!strcmp(state, "on")) 169 led.default_state = LEDS_GPIO_DEFSTATE_ON; 170 else 171 led.default_state = LEDS_GPIO_DEFSTATE_OFF; 172 } 173 174 if (fwnode_property_present(child, "retain-state-suspended")) 175 led.retain_state_suspended = 1; 176 if (fwnode_property_present(child, "retain-state-shutdown")) 177 led.retain_state_shutdown = 1; 178 if (fwnode_property_present(child, "panic-indicator")) 179 led.panic_indicator = 1; 180 181 ret = create_gpio_led(&led, led_dat, dev, child, NULL); 182 if (ret < 0) { 183 fwnode_handle_put(child); 184 return ERR_PTR(ret); 185 } 186 /* Set gpiod label to match the corresponding LED name. */ 187 gpiod_set_consumer_name(led_dat->gpiod, 188 led_dat->cdev.dev->kobj.name); 189 priv->num_leds++; 190 } 191 192 return priv; 193 } 194 195 static const struct of_device_id of_gpio_leds_match[] = { 196 { .compatible = "gpio-leds", }, 197 {}, 198 }; 199 200 MODULE_DEVICE_TABLE(of, of_gpio_leds_match); 201 202 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx, 203 const struct gpio_led *template) 204 { 205 struct gpio_desc *gpiod; 206 unsigned long flags = GPIOF_OUT_INIT_LOW; 207 int ret; 208 209 /* 210 * This means the LED does not come from the device tree 211 * or ACPI, so let's try just getting it by index from the 212 * device, this will hit the board file, if any and get 213 * the GPIO from there. 214 */ 215 gpiod = devm_gpiod_get_index(dev, NULL, idx, GPIOD_OUT_LOW); 216 if (!IS_ERR(gpiod)) { 217 gpiod_set_consumer_name(gpiod, template->name); 218 return gpiod; 219 } 220 if (PTR_ERR(gpiod) != -ENOENT) 221 return gpiod; 222 223 /* 224 * This is the legacy code path for platform code that 225 * still uses GPIO numbers. Ultimately we would like to get 226 * rid of this block completely. 227 */ 228 229 /* skip leds that aren't available */ 230 if (!gpio_is_valid(template->gpio)) 231 return ERR_PTR(-ENOENT); 232 233 if (template->active_low) 234 flags |= GPIOF_ACTIVE_LOW; 235 236 ret = devm_gpio_request_one(dev, template->gpio, flags, 237 template->name); 238 if (ret < 0) 239 return ERR_PTR(ret); 240 241 gpiod = gpio_to_desc(template->gpio); 242 if (!gpiod) 243 return ERR_PTR(-EINVAL); 244 245 return gpiod; 246 } 247 248 static int gpio_led_probe(struct platform_device *pdev) 249 { 250 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev); 251 struct gpio_leds_priv *priv; 252 int i, ret = 0; 253 254 if (pdata && pdata->num_leds) { 255 priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, pdata->num_leds), 256 GFP_KERNEL); 257 if (!priv) 258 return -ENOMEM; 259 260 priv->num_leds = pdata->num_leds; 261 for (i = 0; i < priv->num_leds; i++) { 262 const struct gpio_led *template = &pdata->leds[i]; 263 struct gpio_led_data *led_dat = &priv->leds[i]; 264 265 if (template->gpiod) 266 led_dat->gpiod = template->gpiod; 267 else 268 led_dat->gpiod = 269 gpio_led_get_gpiod(&pdev->dev, 270 i, template); 271 if (IS_ERR(led_dat->gpiod)) { 272 dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n", 273 template->gpio, template->name); 274 continue; 275 } 276 277 ret = create_gpio_led(template, led_dat, 278 &pdev->dev, NULL, 279 pdata->gpio_blink_set); 280 if (ret < 0) 281 return ret; 282 } 283 } else { 284 priv = gpio_leds_create(pdev); 285 if (IS_ERR(priv)) 286 return PTR_ERR(priv); 287 } 288 289 platform_set_drvdata(pdev, priv); 290 291 return 0; 292 } 293 294 static void gpio_led_shutdown(struct platform_device *pdev) 295 { 296 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 297 int i; 298 299 for (i = 0; i < priv->num_leds; i++) { 300 struct gpio_led_data *led = &priv->leds[i]; 301 302 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) 303 gpio_led_set(&led->cdev, LED_OFF); 304 } 305 } 306 307 static struct platform_driver gpio_led_driver = { 308 .probe = gpio_led_probe, 309 .shutdown = gpio_led_shutdown, 310 .driver = { 311 .name = "leds-gpio", 312 .of_match_table = of_gpio_leds_match, 313 }, 314 }; 315 316 module_platform_driver(gpio_led_driver); 317 318 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 319 MODULE_DESCRIPTION("GPIO LED driver"); 320 MODULE_LICENSE("GPL"); 321 MODULE_ALIAS("platform:leds-gpio"); 322