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 inline int sizeof_gpio_leds_priv(int num_leds) 129 { 130 return sizeof(struct gpio_leds_priv) + 131 (sizeof(struct gpio_led_data) * num_leds); 132 } 133 134 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev) 135 { 136 struct device *dev = &pdev->dev; 137 struct fwnode_handle *child; 138 struct gpio_leds_priv *priv; 139 int count, ret; 140 141 count = device_get_child_node_count(dev); 142 if (!count) 143 return ERR_PTR(-ENODEV); 144 145 priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL); 146 if (!priv) 147 return ERR_PTR(-ENOMEM); 148 149 device_for_each_child_node(dev, child) { 150 struct gpio_led_data *led_dat = &priv->leds[priv->num_leds]; 151 struct gpio_led led = {}; 152 const char *state = NULL; 153 154 led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child, 155 GPIOD_ASIS, 156 led.name); 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 fwnode_property_read_string(child, "linux,default-trigger", 165 &led.default_trigger); 166 167 if (!fwnode_property_read_string(child, "default-state", 168 &state)) { 169 if (!strcmp(state, "keep")) 170 led.default_state = LEDS_GPIO_DEFSTATE_KEEP; 171 else if (!strcmp(state, "on")) 172 led.default_state = LEDS_GPIO_DEFSTATE_ON; 173 else 174 led.default_state = LEDS_GPIO_DEFSTATE_OFF; 175 } 176 177 if (fwnode_property_present(child, "retain-state-suspended")) 178 led.retain_state_suspended = 1; 179 if (fwnode_property_present(child, "retain-state-shutdown")) 180 led.retain_state_shutdown = 1; 181 if (fwnode_property_present(child, "panic-indicator")) 182 led.panic_indicator = 1; 183 184 ret = create_gpio_led(&led, led_dat, dev, child, NULL); 185 if (ret < 0) { 186 fwnode_handle_put(child); 187 return ERR_PTR(ret); 188 } 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, flags); 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, 256 sizeof_gpio_leds_priv(pdata->num_leds), 257 GFP_KERNEL); 258 if (!priv) 259 return -ENOMEM; 260 261 priv->num_leds = pdata->num_leds; 262 for (i = 0; i < priv->num_leds; i++) { 263 const struct gpio_led *template = &pdata->leds[i]; 264 struct gpio_led_data *led_dat = &priv->leds[i]; 265 266 if (template->gpiod) 267 led_dat->gpiod = template->gpiod; 268 else 269 led_dat->gpiod = 270 gpio_led_get_gpiod(&pdev->dev, 271 i, template); 272 if (IS_ERR(led_dat->gpiod)) { 273 dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n", 274 template->gpio, template->name); 275 continue; 276 } 277 278 ret = create_gpio_led(template, led_dat, 279 &pdev->dev, NULL, 280 pdata->gpio_blink_set); 281 if (ret < 0) 282 return ret; 283 } 284 } else { 285 priv = gpio_leds_create(pdev); 286 if (IS_ERR(priv)) 287 return PTR_ERR(priv); 288 } 289 290 platform_set_drvdata(pdev, priv); 291 292 return 0; 293 } 294 295 static void gpio_led_shutdown(struct platform_device *pdev) 296 { 297 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 298 int i; 299 300 for (i = 0; i < priv->num_leds; i++) { 301 struct gpio_led_data *led = &priv->leds[i]; 302 303 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) 304 gpio_led_set(&led->cdev, LED_OFF); 305 } 306 } 307 308 static struct platform_driver gpio_led_driver = { 309 .probe = gpio_led_probe, 310 .shutdown = gpio_led_shutdown, 311 .driver = { 312 .name = "leds-gpio", 313 .of_match_table = of_gpio_leds_match, 314 }, 315 }; 316 317 module_platform_driver(gpio_led_driver); 318 319 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 320 MODULE_DESCRIPTION("GPIO LED driver"); 321 MODULE_LICENSE("GPL"); 322 MODULE_ALIAS("platform:leds-gpio"); 323