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 int (*platform_gpio_blink_set)(struct gpio_desc *desc, int state, 30 unsigned long *delay_on, unsigned long *delay_off); 31 }; 32 33 static void gpio_led_set(struct led_classdev *led_cdev, 34 enum led_brightness value) 35 { 36 struct gpio_led_data *led_dat = 37 container_of(led_cdev, struct gpio_led_data, 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 = 68 container_of(led_cdev, struct gpio_led_data, cdev); 69 70 led_dat->blinking = 1; 71 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK, 72 delay_on, delay_off); 73 } 74 75 static int create_gpio_led(const struct gpio_led *template, 76 struct gpio_led_data *led_dat, struct device *parent, 77 int (*blink_set)(struct gpio_desc *, int, unsigned long *, 78 unsigned long *)) 79 { 80 int ret, state; 81 82 led_dat->gpiod = template->gpiod; 83 if (!led_dat->gpiod) { 84 /* 85 * This is the legacy code path for platform code that 86 * still uses GPIO numbers. Ultimately we would like to get 87 * rid of this block completely. 88 */ 89 unsigned long flags = 0; 90 91 /* skip leds that aren't available */ 92 if (!gpio_is_valid(template->gpio)) { 93 dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n", 94 template->gpio, template->name); 95 return 0; 96 } 97 98 if (template->active_low) 99 flags |= GPIOF_ACTIVE_LOW; 100 101 ret = devm_gpio_request_one(parent, template->gpio, flags, 102 template->name); 103 if (ret < 0) 104 return ret; 105 106 led_dat->gpiod = gpio_to_desc(template->gpio); 107 if (IS_ERR(led_dat->gpiod)) 108 return PTR_ERR(led_dat->gpiod); 109 } 110 111 led_dat->cdev.name = template->name; 112 led_dat->cdev.default_trigger = template->default_trigger; 113 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod); 114 if (!led_dat->can_sleep) 115 led_dat->cdev.brightness_set = gpio_led_set; 116 else 117 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking; 118 led_dat->blinking = 0; 119 if (blink_set) { 120 led_dat->platform_gpio_blink_set = blink_set; 121 led_dat->cdev.blink_set = gpio_blink_set; 122 } 123 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) 124 state = !!gpiod_get_value_cansleep(led_dat->gpiod); 125 else 126 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); 127 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF; 128 if (!template->retain_state_suspended) 129 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 130 131 ret = gpiod_direction_output(led_dat->gpiod, state); 132 if (ret < 0) 133 return ret; 134 135 return led_classdev_register(parent, &led_dat->cdev); 136 } 137 138 struct gpio_leds_priv { 139 int num_leds; 140 struct gpio_led_data leds[]; 141 }; 142 143 static inline int sizeof_gpio_leds_priv(int num_leds) 144 { 145 return sizeof(struct gpio_leds_priv) + 146 (sizeof(struct gpio_led_data) * num_leds); 147 } 148 149 static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev) 150 { 151 struct device *dev = &pdev->dev; 152 struct fwnode_handle *child; 153 struct gpio_leds_priv *priv; 154 int count, ret; 155 struct device_node *np; 156 157 count = device_get_child_node_count(dev); 158 if (!count) 159 return ERR_PTR(-ENODEV); 160 161 priv = devm_kzalloc(dev, sizeof_gpio_leds_priv(count), GFP_KERNEL); 162 if (!priv) 163 return ERR_PTR(-ENOMEM); 164 165 device_for_each_child_node(dev, child) { 166 struct gpio_led led = {}; 167 const char *state = NULL; 168 169 led.gpiod = devm_get_gpiod_from_child(dev, NULL, child); 170 if (IS_ERR(led.gpiod)) { 171 fwnode_handle_put(child); 172 ret = PTR_ERR(led.gpiod); 173 goto err; 174 } 175 176 np = to_of_node(child); 177 178 if (fwnode_property_present(child, "label")) { 179 fwnode_property_read_string(child, "label", &led.name); 180 } else { 181 if (IS_ENABLED(CONFIG_OF) && !led.name && np) 182 led.name = np->name; 183 if (!led.name) { 184 ret = -EINVAL; 185 goto err; 186 } 187 } 188 fwnode_property_read_string(child, "linux,default-trigger", 189 &led.default_trigger); 190 191 if (!fwnode_property_read_string(child, "default-state", 192 &state)) { 193 if (!strcmp(state, "keep")) 194 led.default_state = LEDS_GPIO_DEFSTATE_KEEP; 195 else if (!strcmp(state, "on")) 196 led.default_state = LEDS_GPIO_DEFSTATE_ON; 197 else 198 led.default_state = LEDS_GPIO_DEFSTATE_OFF; 199 } 200 201 if (fwnode_property_present(child, "retain-state-suspended")) 202 led.retain_state_suspended = 1; 203 204 ret = create_gpio_led(&led, &priv->leds[priv->num_leds], 205 dev, NULL); 206 if (ret < 0) { 207 fwnode_handle_put(child); 208 goto err; 209 } 210 priv->num_leds++; 211 } 212 213 return priv; 214 215 err: 216 for (count = priv->num_leds - 1; count >= 0; count--) 217 led_classdev_unregister(&priv->leds[count].cdev); 218 return ERR_PTR(ret); 219 } 220 221 static const struct of_device_id of_gpio_leds_match[] = { 222 { .compatible = "gpio-leds", }, 223 {}, 224 }; 225 226 MODULE_DEVICE_TABLE(of, of_gpio_leds_match); 227 228 static int gpio_led_probe(struct platform_device *pdev) 229 { 230 struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev); 231 struct gpio_leds_priv *priv; 232 int i, ret = 0; 233 234 if (pdata && pdata->num_leds) { 235 priv = devm_kzalloc(&pdev->dev, 236 sizeof_gpio_leds_priv(pdata->num_leds), 237 GFP_KERNEL); 238 if (!priv) 239 return -ENOMEM; 240 241 priv->num_leds = pdata->num_leds; 242 for (i = 0; i < priv->num_leds; i++) { 243 ret = create_gpio_led(&pdata->leds[i], 244 &priv->leds[i], 245 &pdev->dev, pdata->gpio_blink_set); 246 if (ret < 0) { 247 /* On failure: unwind the led creations */ 248 for (i = i - 1; i >= 0; i--) 249 led_classdev_unregister( 250 &priv->leds[i].cdev); 251 return ret; 252 } 253 } 254 } else { 255 priv = gpio_leds_create(pdev); 256 if (IS_ERR(priv)) 257 return PTR_ERR(priv); 258 } 259 260 platform_set_drvdata(pdev, priv); 261 262 return 0; 263 } 264 265 static int gpio_led_remove(struct platform_device *pdev) 266 { 267 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 268 int i; 269 270 for (i = 0; i < priv->num_leds; i++) 271 led_classdev_unregister(&priv->leds[i].cdev); 272 273 return 0; 274 } 275 276 static void gpio_led_shutdown(struct platform_device *pdev) 277 { 278 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 279 int i; 280 281 for (i = 0; i < priv->num_leds; i++) { 282 struct gpio_led_data *led = &priv->leds[i]; 283 284 gpio_led_set(&led->cdev, LED_OFF); 285 } 286 } 287 288 static struct platform_driver gpio_led_driver = { 289 .probe = gpio_led_probe, 290 .remove = gpio_led_remove, 291 .shutdown = gpio_led_shutdown, 292 .driver = { 293 .name = "leds-gpio", 294 .of_match_table = of_gpio_leds_match, 295 }, 296 }; 297 298 module_platform_driver(gpio_led_driver); 299 300 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 301 MODULE_DESCRIPTION("GPIO LED driver"); 302 MODULE_LICENSE("GPL"); 303 MODULE_ALIAS("platform:leds-gpio"); 304