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/container_of.h> 10 #include <linux/device.h> 11 #include <linux/err.h> 12 #include <linux/gpio.h> 13 #include <linux/gpio/consumer.h> 14 #include <linux/leds.h> 15 #include <linux/module.h> 16 #include <linux/overflow.h> 17 #include <linux/pinctrl/consumer.h> 18 #include <linux/platform_device.h> 19 #include <linux/property.h> 20 #include <linux/slab.h> 21 #include <linux/types.h> 22 23 struct gpio_led_data { 24 struct led_classdev cdev; 25 struct gpio_desc *gpiod; 26 u8 can_sleep; 27 u8 blinking; 28 gpio_blink_set_t platform_gpio_blink_set; 29 }; 30 31 static inline struct gpio_led_data * 32 cdev_to_gpio_led_data(struct led_classdev *led_cdev) 33 { 34 return container_of(led_cdev, struct gpio_led_data, cdev); 35 } 36 37 static void gpio_led_set(struct led_classdev *led_cdev, 38 enum led_brightness value) 39 { 40 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 41 int level; 42 43 if (value == LED_OFF) 44 level = 0; 45 else 46 level = 1; 47 48 if (led_dat->blinking) { 49 led_dat->platform_gpio_blink_set(led_dat->gpiod, level, 50 NULL, NULL); 51 led_dat->blinking = 0; 52 } else { 53 if (led_dat->can_sleep) 54 gpiod_set_value_cansleep(led_dat->gpiod, level); 55 else 56 gpiod_set_value(led_dat->gpiod, level); 57 } 58 } 59 60 static int gpio_led_set_blocking(struct led_classdev *led_cdev, 61 enum led_brightness value) 62 { 63 gpio_led_set(led_cdev, value); 64 return 0; 65 } 66 67 static int gpio_blink_set(struct led_classdev *led_cdev, 68 unsigned long *delay_on, unsigned long *delay_off) 69 { 70 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 71 72 led_dat->blinking = 1; 73 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK, 74 delay_on, delay_off); 75 } 76 77 static int create_gpio_led(const struct gpio_led *template, 78 struct gpio_led_data *led_dat, struct device *parent, 79 struct fwnode_handle *fwnode, gpio_blink_set_t blink_set) 80 { 81 struct led_init_data init_data = {}; 82 struct pinctrl *pinctrl; 83 int ret, state; 84 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; 104 led_dat->cdev.max_brightness = 1; 105 if (!template->retain_state_suspended) 106 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 107 if (template->panic_indicator) 108 led_dat->cdev.flags |= LED_PANIC_INDICATOR; 109 if (template->retain_state_shutdown) 110 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN; 111 112 ret = gpiod_direction_output(led_dat->gpiod, state); 113 if (ret < 0) 114 return ret; 115 116 if (template->name) { 117 led_dat->cdev.name = template->name; 118 ret = devm_led_classdev_register(parent, &led_dat->cdev); 119 } else { 120 init_data.fwnode = fwnode; 121 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev, 122 &init_data); 123 } 124 125 if (ret) 126 return ret; 127 128 pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev); 129 ret = PTR_ERR_OR_ZERO(pinctrl); 130 /* pinctrl-%d not present, not an error */ 131 if (ret == -ENODEV) 132 ret = 0; 133 if (ret) { 134 dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n", 135 fwnode, ret); 136 } 137 138 return ret; 139 } 140 141 struct gpio_leds_priv { 142 int num_leds; 143 struct gpio_led_data leds[] __counted_by(num_leds); 144 }; 145 146 static struct gpio_leds_priv *gpio_leds_create(struct device *dev) 147 { 148 struct gpio_leds_priv *priv; 149 int count, used, ret; 150 151 count = device_get_child_node_count(dev); 152 if (!count) 153 return ERR_PTR(-ENODEV); 154 155 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL); 156 if (!priv) 157 return ERR_PTR(-ENOMEM); 158 priv->num_leds = count; 159 used = 0; 160 161 device_for_each_child_node_scoped(dev, child) { 162 struct gpio_led_data *led_dat = &priv->leds[used]; 163 struct gpio_led led = {}; 164 165 /* 166 * Acquire gpiod from DT with uninitialized label, which 167 * will be updated after LED class device is registered, 168 * Only then the final LED name is known. 169 */ 170 led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS, 171 NULL); 172 if (IS_ERR(led.gpiod)) { 173 dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n", 174 child); 175 return ERR_CAST(led.gpiod); 176 } 177 178 led_dat->gpiod = led.gpiod; 179 180 led.default_state = led_init_default_state_get(child); 181 182 if (fwnode_property_present(child, "retain-state-suspended")) 183 led.retain_state_suspended = 1; 184 if (fwnode_property_present(child, "retain-state-shutdown")) 185 led.retain_state_shutdown = 1; 186 if (fwnode_property_present(child, "panic-indicator")) 187 led.panic_indicator = 1; 188 189 ret = create_gpio_led(&led, led_dat, dev, child, NULL); 190 if (ret < 0) 191 return ERR_PTR(ret); 192 193 /* Set gpiod label to match the corresponding LED name. */ 194 gpiod_set_consumer_name(led_dat->gpiod, 195 led_dat->cdev.dev->kobj.name); 196 used++; 197 } 198 priv->num_leds = used; 199 200 return priv; 201 } 202 203 static const struct of_device_id of_gpio_leds_match[] = { 204 { .compatible = "gpio-leds", }, 205 {}, 206 }; 207 208 MODULE_DEVICE_TABLE(of, of_gpio_leds_match); 209 210 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx, 211 const struct gpio_led *template) 212 { 213 struct gpio_desc *gpiod; 214 int ret; 215 216 /* 217 * This means the LED does not come from the device tree 218 * or ACPI, so let's try just getting it by index from the 219 * device, this will hit the board file, if any and get 220 * the GPIO from there. 221 */ 222 gpiod = devm_gpiod_get_index_optional(dev, NULL, idx, GPIOD_OUT_LOW); 223 if (IS_ERR(gpiod)) 224 return gpiod; 225 if (gpiod) { 226 gpiod_set_consumer_name(gpiod, template->name); 227 return gpiod; 228 } 229 230 /* 231 * This is the legacy code path for platform code that 232 * still uses GPIO numbers. Ultimately we would like to get 233 * rid of this block completely. 234 */ 235 236 /* skip leds that aren't available */ 237 if (!gpio_is_valid(template->gpio)) 238 return ERR_PTR(-ENOENT); 239 240 ret = devm_gpio_request_one(dev, template->gpio, GPIOF_OUT_INIT_LOW, 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 if (template->active_low ^ gpiod_is_active_low(gpiod)) 250 gpiod_toggle_active_low(gpiod); 251 252 return gpiod; 253 } 254 255 static int gpio_led_probe(struct platform_device *pdev) 256 { 257 struct device *dev = &pdev->dev; 258 struct gpio_led_platform_data *pdata = dev_get_platdata(dev); 259 struct gpio_leds_priv *priv; 260 int i, ret; 261 262 if (pdata && pdata->num_leds) { 263 priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL); 264 if (!priv) 265 return -ENOMEM; 266 267 priv->num_leds = pdata->num_leds; 268 for (i = 0; i < priv->num_leds; i++) { 269 const struct gpio_led *template = &pdata->leds[i]; 270 struct gpio_led_data *led_dat = &priv->leds[i]; 271 272 if (template->gpiod) 273 led_dat->gpiod = template->gpiod; 274 else 275 led_dat->gpiod = 276 gpio_led_get_gpiod(dev, i, template); 277 if (IS_ERR(led_dat->gpiod)) { 278 dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n", 279 template->gpio, template->name); 280 continue; 281 } 282 283 ret = create_gpio_led(template, led_dat, dev, NULL, 284 pdata->gpio_blink_set); 285 if (ret < 0) 286 return ret; 287 } 288 } else { 289 priv = gpio_leds_create(dev); 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