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