1 /* 2 * LEDs driver for GPIOs 3 * 4 * Copyright (C) 2007 8D Technologies inc. 5 * Raphael Assenat <raph@8d.com> 6 * Copyright (C) 2008 Freescale Semiconductor, Inc. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 */ 13 #include <linux/err.h> 14 #include <linux/gpio.h> 15 #include <linux/gpio/consumer.h> 16 #include <linux/kernel.h> 17 #include <linux/leds.h> 18 #include <linux/module.h> 19 #include <linux/of.h> 20 #include <linux/platform_device.h> 21 #include <linux/property.h> 22 #include <linux/slab.h> 23 24 struct gpio_led_data { 25 struct led_classdev cdev; 26 struct gpio_desc *gpiod; 27 u8 can_sleep; 28 u8 blinking; 29 gpio_blink_set_t platform_gpio_blink_set; 30 }; 31 32 static inline struct gpio_led_data * 33 cdev_to_gpio_led_data(struct led_classdev *led_cdev) 34 { 35 return container_of(led_cdev, struct gpio_led_data, cdev); 36 } 37 38 static void gpio_led_set(struct led_classdev *led_cdev, 39 enum led_brightness value) 40 { 41 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 42 int level; 43 44 if (value == LED_OFF) 45 level = 0; 46 else 47 level = 1; 48 49 if (led_dat->blinking) { 50 led_dat->platform_gpio_blink_set(led_dat->gpiod, level, 51 NULL, NULL); 52 led_dat->blinking = 0; 53 } else { 54 if (led_dat->can_sleep) 55 gpiod_set_value_cansleep(led_dat->gpiod, level); 56 else 57 gpiod_set_value(led_dat->gpiod, level); 58 } 59 } 60 61 static int gpio_led_set_blocking(struct led_classdev *led_cdev, 62 enum led_brightness value) 63 { 64 gpio_led_set(led_cdev, value); 65 return 0; 66 } 67 68 static int gpio_blink_set(struct led_classdev *led_cdev, 69 unsigned long *delay_on, unsigned long *delay_off) 70 { 71 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 72 73 led_dat->blinking = 1; 74 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK, 75 delay_on, delay_off); 76 } 77 78 static int create_gpio_led(const struct gpio_led *template, 79 struct gpio_led_data *led_dat, struct device *parent, 80 struct device_node *np, gpio_blink_set_t blink_set) 81 { 82 int ret, state; 83 84 led_dat->cdev.name = template->name; 85 led_dat->cdev.default_trigger = template->default_trigger; 86 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod); 87 if (!led_dat->can_sleep) 88 led_dat->cdev.brightness_set = gpio_led_set; 89 else 90 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking; 91 led_dat->blinking = 0; 92 if (blink_set) { 93 led_dat->platform_gpio_blink_set = blink_set; 94 led_dat->cdev.blink_set = gpio_blink_set; 95 } 96 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) { 97 state = gpiod_get_value_cansleep(led_dat->gpiod); 98 if (state < 0) 99 return state; 100 } else { 101 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); 102 } 103 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF; 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 return devm_of_led_classdev_register(parent, np, &led_dat->cdev); 116 } 117 118 struct gpio_leds_priv { 119 int num_leds; 120 struct gpio_led_data leds[]; 121 }; 122 123 static inline int sizeof_gpio_leds_priv(int num_leds) 124 { 125 return sizeof(struct gpio_leds_priv) + 126 (sizeof(struct gpio_led_data) * num_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, sizeof_gpio_leds_priv(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 struct device_node *np = to_of_node(child); 149 150 ret = fwnode_property_read_string(child, "label", &led.name); 151 if (ret && IS_ENABLED(CONFIG_OF) && np) 152 led.name = np->name; 153 if (!led.name) { 154 fwnode_handle_put(child); 155 return ERR_PTR(-EINVAL); 156 } 157 158 led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child, 159 GPIOD_ASIS, 160 led.name); 161 if (IS_ERR(led.gpiod)) { 162 fwnode_handle_put(child); 163 return ERR_CAST(led.gpiod); 164 } 165 166 led_dat->gpiod = led.gpiod; 167 168 fwnode_property_read_string(child, "linux,default-trigger", 169 &led.default_trigger); 170 171 if (!fwnode_property_read_string(child, "default-state", 172 &state)) { 173 if (!strcmp(state, "keep")) 174 led.default_state = LEDS_GPIO_DEFSTATE_KEEP; 175 else if (!strcmp(state, "on")) 176 led.default_state = LEDS_GPIO_DEFSTATE_ON; 177 else 178 led.default_state = LEDS_GPIO_DEFSTATE_OFF; 179 } 180 181 if (fwnode_property_present(child, "retain-state-suspended")) 182 led.retain_state_suspended = 1; 183 if (fwnode_property_present(child, "retain-state-shutdown")) 184 led.retain_state_shutdown = 1; 185 if (fwnode_property_present(child, "panic-indicator")) 186 led.panic_indicator = 1; 187 188 ret = create_gpio_led(&led, led_dat, dev, np, NULL); 189 if (ret < 0) { 190 fwnode_handle_put(child); 191 return ERR_PTR(ret); 192 } 193 priv->num_leds++; 194 } 195 196 return priv; 197 } 198 199 static const struct of_device_id of_gpio_leds_match[] = { 200 { .compatible = "gpio-leds", }, 201 {}, 202 }; 203 204 MODULE_DEVICE_TABLE(of, of_gpio_leds_match); 205 206 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx, 207 const struct gpio_led *template) 208 { 209 struct gpio_desc *gpiod; 210 unsigned long flags = GPIOF_OUT_INIT_LOW; 211 int ret; 212 213 /* 214 * This means the LED does not come from the device tree 215 * or ACPI, so let's try just getting it by index from the 216 * device, this will hit the board file, if any and get 217 * the GPIO from there. 218 */ 219 gpiod = devm_gpiod_get_index(dev, NULL, idx, flags); 220 if (!IS_ERR(gpiod)) { 221 gpiod_set_consumer_name(gpiod, template->name); 222 return gpiod; 223 } 224 if (PTR_ERR(gpiod) != -ENOENT) 225 return gpiod; 226 227 /* 228 * This is the legacy code path for platform code that 229 * still uses GPIO numbers. Ultimately we would like to get 230 * rid of this block completely. 231 */ 232 233 /* skip leds that aren't available */ 234 if (!gpio_is_valid(template->gpio)) 235 return ERR_PTR(-ENOENT); 236 237 if (template->active_low) 238 flags |= GPIOF_ACTIVE_LOW; 239 240 ret = devm_gpio_request_one(dev, template->gpio, flags, 241 template->name); 242 if (ret < 0) 243 return ERR_PTR(ret); 244 245 gpiod = gpio_to_desc(template->gpio); 246 if (!gpiod) 247 return ERR_PTR(-EINVAL); 248 249 return gpiod; 250 } 251 252 static int gpio_led_probe(struct platform_device *pdev) 253 { 254 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev); 255 struct gpio_leds_priv *priv; 256 int i, ret = 0; 257 258 if (pdata && pdata->num_leds) { 259 priv = devm_kzalloc(&pdev->dev, 260 sizeof_gpio_leds_priv(pdata->num_leds), 261 GFP_KERNEL); 262 if (!priv) 263 return -ENOMEM; 264 265 priv->num_leds = pdata->num_leds; 266 for (i = 0; i < priv->num_leds; i++) { 267 const struct gpio_led *template = &pdata->leds[i]; 268 struct gpio_led_data *led_dat = &priv->leds[i]; 269 270 if (template->gpiod) 271 led_dat->gpiod = template->gpiod; 272 else 273 led_dat->gpiod = 274 gpio_led_get_gpiod(&pdev->dev, 275 i, template); 276 if (IS_ERR(led_dat->gpiod)) { 277 dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)\n", 278 template->gpio, template->name); 279 continue; 280 } 281 282 ret = create_gpio_led(template, led_dat, 283 &pdev->dev, NULL, 284 pdata->gpio_blink_set); 285 if (ret < 0) 286 return ret; 287 } 288 } else { 289 priv = gpio_leds_create(pdev); 290 if (IS_ERR(priv)) 291 return PTR_ERR(priv); 292 } 293 294 platform_set_drvdata(pdev, priv); 295 296 return 0; 297 } 298 299 static void gpio_led_shutdown(struct platform_device *pdev) 300 { 301 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 302 int i; 303 304 for (i = 0; i < priv->num_leds; i++) { 305 struct gpio_led_data *led = &priv->leds[i]; 306 307 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) 308 gpio_led_set(&led->cdev, LED_OFF); 309 } 310 } 311 312 static struct platform_driver gpio_led_driver = { 313 .probe = gpio_led_probe, 314 .shutdown = gpio_led_shutdown, 315 .driver = { 316 .name = "leds-gpio", 317 .of_match_table = of_gpio_leds_match, 318 }, 319 }; 320 321 module_platform_driver(gpio_led_driver); 322 323 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 324 MODULE_DESCRIPTION("GPIO LED driver"); 325 MODULE_LICENSE("GPL"); 326 MODULE_ALIAS("platform:leds-gpio"); 327