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/mod_devicetable.h> 16 #include <linux/module.h> 17 #include <linux/overflow.h> 18 #include <linux/pinctrl/consumer.h> 19 #include <linux/platform_device.h> 20 #include <linux/property.h> 21 #include <linux/slab.h> 22 #include <linux/types.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 fwnode_handle *fwnode, gpio_blink_set_t blink_set) 81 { 82 struct led_init_data init_data = {}; 83 struct pinctrl *pinctrl; 84 int ret, state; 85 86 led_dat->cdev.default_trigger = template->default_trigger; 87 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod); 88 if (!led_dat->can_sleep) 89 led_dat->cdev.brightness_set = gpio_led_set; 90 else 91 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking; 92 led_dat->blinking = 0; 93 if (blink_set) { 94 led_dat->platform_gpio_blink_set = blink_set; 95 led_dat->cdev.blink_set = gpio_blink_set; 96 } 97 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) { 98 state = gpiod_get_value_cansleep(led_dat->gpiod); 99 if (state < 0) 100 return state; 101 } else { 102 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); 103 } 104 led_dat->cdev.brightness = state; 105 led_dat->cdev.max_brightness = 1; 106 if (!template->retain_state_suspended) 107 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 108 if (template->panic_indicator) 109 led_dat->cdev.flags |= LED_PANIC_INDICATOR; 110 if (template->retain_state_shutdown) 111 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN; 112 113 ret = gpiod_direction_output(led_dat->gpiod, state); 114 if (ret < 0) 115 return ret; 116 117 if (template->name) { 118 led_dat->cdev.name = template->name; 119 ret = devm_led_classdev_register(parent, &led_dat->cdev); 120 } else { 121 init_data.fwnode = fwnode; 122 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev, 123 &init_data); 124 } 125 126 if (ret) 127 return ret; 128 129 pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev); 130 ret = PTR_ERR_OR_ZERO(pinctrl); 131 /* pinctrl-%d not present, not an error */ 132 if (ret == -ENODEV) 133 ret = 0; 134 if (ret) { 135 dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n", 136 fwnode, ret); 137 } 138 139 return ret; 140 } 141 142 struct gpio_leds_priv { 143 int num_leds; 144 struct gpio_led_data leds[] __counted_by(num_leds); 145 }; 146 147 static struct gpio_leds_priv *gpio_leds_create(struct device *dev) 148 { 149 struct gpio_leds_priv *priv; 150 int count, used, ret; 151 152 count = device_get_child_node_count(dev); 153 if (!count) 154 return ERR_PTR(-ENODEV); 155 156 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL); 157 if (!priv) 158 return ERR_PTR(-ENOMEM); 159 priv->num_leds = count; 160 used = 0; 161 162 device_for_each_child_node_scoped(dev, child) { 163 struct gpio_led_data *led_dat = &priv->leds[used]; 164 struct gpio_led led = {}; 165 166 /* 167 * Acquire gpiod from DT with uninitialized label, which 168 * will be updated after LED class device is registered, 169 * Only then the final LED name is known. 170 */ 171 led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS, 172 NULL); 173 if (IS_ERR(led.gpiod)) { 174 dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n", 175 child); 176 return ERR_CAST(led.gpiod); 177 } 178 179 led_dat->gpiod = led.gpiod; 180 181 led.default_state = led_init_default_state_get(child); 182 183 if (fwnode_property_present(child, "retain-state-suspended")) 184 led.retain_state_suspended = 1; 185 if (fwnode_property_present(child, "retain-state-shutdown")) 186 led.retain_state_shutdown = 1; 187 if (fwnode_property_present(child, "panic-indicator")) 188 led.panic_indicator = 1; 189 190 ret = create_gpio_led(&led, led_dat, dev, child, NULL); 191 if (ret < 0) 192 return ERR_PTR(ret); 193 194 /* Set gpiod label to match the corresponding LED name. */ 195 gpiod_set_consumer_name(led_dat->gpiod, 196 led_dat->cdev.dev->kobj.name); 197 used++; 198 } 199 priv->num_leds = used; 200 201 return priv; 202 } 203 204 static const struct of_device_id of_gpio_leds_match[] = { 205 { .compatible = "gpio-leds", }, 206 {}, 207 }; 208 209 MODULE_DEVICE_TABLE(of, of_gpio_leds_match); 210 211 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx, 212 const struct gpio_led *template) 213 { 214 struct gpio_desc *gpiod; 215 int ret; 216 217 /* 218 * This means the LED does not come from the device tree 219 * or ACPI, so let's try just getting it by index from the 220 * device, this will hit the board file, if any and get 221 * the GPIO from there. 222 */ 223 gpiod = devm_gpiod_get_index_optional(dev, NULL, idx, GPIOD_OUT_LOW); 224 if (IS_ERR(gpiod)) 225 return gpiod; 226 if (gpiod) { 227 gpiod_set_consumer_name(gpiod, template->name); 228 return gpiod; 229 } 230 231 /* 232 * This is the legacy code path for platform code that 233 * still uses GPIO numbers. Ultimately we would like to get 234 * rid of this block completely. 235 */ 236 237 /* skip leds that aren't available */ 238 if (!gpio_is_valid(template->gpio)) 239 return ERR_PTR(-ENOENT); 240 241 ret = devm_gpio_request_one(dev, template->gpio, GPIOF_OUT_INIT_LOW, 242 template->name); 243 if (ret < 0) 244 return ERR_PTR(ret); 245 246 gpiod = gpio_to_desc(template->gpio); 247 if (!gpiod) 248 return ERR_PTR(-EINVAL); 249 250 if (template->active_low ^ gpiod_is_active_low(gpiod)) 251 gpiod_toggle_active_low(gpiod); 252 253 return gpiod; 254 } 255 256 static int gpio_led_probe(struct platform_device *pdev) 257 { 258 struct device *dev = &pdev->dev; 259 struct gpio_led_platform_data *pdata = dev_get_platdata(dev); 260 struct gpio_leds_priv *priv; 261 int i, ret; 262 263 if (pdata && pdata->num_leds) { 264 priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL); 265 if (!priv) 266 return -ENOMEM; 267 268 priv->num_leds = pdata->num_leds; 269 for (i = 0; i < priv->num_leds; i++) { 270 const struct gpio_led *template = &pdata->leds[i]; 271 struct gpio_led_data *led_dat = &priv->leds[i]; 272 273 if (template->gpiod) 274 led_dat->gpiod = template->gpiod; 275 else 276 led_dat->gpiod = 277 gpio_led_get_gpiod(dev, i, template); 278 if (IS_ERR(led_dat->gpiod)) { 279 dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n", 280 template->gpio, template->name); 281 continue; 282 } 283 284 ret = create_gpio_led(template, led_dat, dev, NULL, 285 pdata->gpio_blink_set); 286 if (ret < 0) 287 return ret; 288 } 289 } else { 290 priv = gpio_leds_create(dev); 291 if (IS_ERR(priv)) 292 return PTR_ERR(priv); 293 } 294 295 platform_set_drvdata(pdev, priv); 296 297 return 0; 298 } 299 300 static void gpio_led_shutdown(struct platform_device *pdev) 301 { 302 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 303 int i; 304 305 for (i = 0; i < priv->num_leds; i++) { 306 struct gpio_led_data *led = &priv->leds[i]; 307 308 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) 309 gpio_led_set(&led->cdev, LED_OFF); 310 } 311 } 312 313 static struct platform_driver gpio_led_driver = { 314 .probe = gpio_led_probe, 315 .shutdown = gpio_led_shutdown, 316 .driver = { 317 .name = "leds-gpio", 318 .of_match_table = of_gpio_leds_match, 319 }, 320 }; 321 322 module_platform_driver(gpio_led_driver); 323 324 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 325 MODULE_DESCRIPTION("GPIO LED driver"); 326 MODULE_LICENSE("GPL"); 327 MODULE_ALIAS("platform:leds-gpio"); 328