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 #include "leds.h" 25 26 struct gpio_led_data { 27 struct led_classdev cdev; 28 struct gpio_desc *gpiod; 29 u8 can_sleep; 30 u8 blinking; 31 gpio_blink_set_t platform_gpio_blink_set; 32 }; 33 34 static inline struct gpio_led_data * 35 cdev_to_gpio_led_data(struct led_classdev *led_cdev) 36 { 37 return container_of(led_cdev, struct gpio_led_data, cdev); 38 } 39 40 static void gpio_led_set(struct led_classdev *led_cdev, 41 enum led_brightness value) 42 { 43 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 44 int level; 45 46 if (value == LED_OFF) 47 level = 0; 48 else 49 level = 1; 50 51 if (led_dat->blinking) { 52 led_dat->platform_gpio_blink_set(led_dat->gpiod, level, 53 NULL, NULL); 54 led_dat->blinking = 0; 55 } else { 56 if (led_dat->can_sleep) 57 gpiod_set_value_cansleep(led_dat->gpiod, level); 58 else 59 gpiod_set_value(led_dat->gpiod, level); 60 } 61 } 62 63 static int gpio_led_set_blocking(struct led_classdev *led_cdev, 64 enum led_brightness value) 65 { 66 gpio_led_set(led_cdev, value); 67 return 0; 68 } 69 70 static int gpio_blink_set(struct led_classdev *led_cdev, 71 unsigned long *delay_on, unsigned long *delay_off) 72 { 73 struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev); 74 75 led_dat->blinking = 1; 76 return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK, 77 delay_on, delay_off); 78 } 79 80 static int create_gpio_led(const struct gpio_led *template, 81 struct gpio_led_data *led_dat, struct device *parent, 82 struct fwnode_handle *fwnode, gpio_blink_set_t blink_set) 83 { 84 struct led_init_data init_data = {}; 85 struct pinctrl *pinctrl; 86 int ret, state; 87 88 led_dat->cdev.default_trigger = template->default_trigger; 89 led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod); 90 if (!led_dat->can_sleep) 91 led_dat->cdev.brightness_set = gpio_led_set; 92 else 93 led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking; 94 led_dat->blinking = 0; 95 if (blink_set) { 96 led_dat->platform_gpio_blink_set = blink_set; 97 led_dat->cdev.blink_set = gpio_blink_set; 98 } 99 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) { 100 state = gpiod_get_value_cansleep(led_dat->gpiod); 101 if (state < 0) 102 return state; 103 } else { 104 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); 105 } 106 led_dat->cdev.brightness = state; 107 led_dat->cdev.max_brightness = 1; 108 if (!template->retain_state_suspended) 109 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 110 if (template->panic_indicator) 111 led_dat->cdev.flags |= LED_PANIC_INDICATOR; 112 if (template->retain_state_shutdown) 113 led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN; 114 115 ret = gpiod_direction_output(led_dat->gpiod, state); 116 if (ret < 0) 117 return ret; 118 119 if (template->name) { 120 led_dat->cdev.name = template->name; 121 ret = devm_led_classdev_register(parent, &led_dat->cdev); 122 } else { 123 init_data.fwnode = fwnode; 124 ret = devm_led_classdev_register_ext(parent, &led_dat->cdev, 125 &init_data); 126 } 127 128 if (ret) 129 return ret; 130 131 pinctrl = devm_pinctrl_get_select_default(led_dat->cdev.dev); 132 ret = PTR_ERR_OR_ZERO(pinctrl); 133 /* pinctrl-%d not present, not an error */ 134 if (ret == -ENODEV) 135 ret = 0; 136 if (ret) { 137 dev_warn(led_dat->cdev.dev, "Failed to select %pfw pinctrl: %d\n", 138 fwnode, ret); 139 } 140 141 return ret; 142 } 143 144 struct gpio_leds_priv { 145 int num_leds; 146 struct gpio_led_data leds[] __counted_by(num_leds); 147 }; 148 149 static struct gpio_leds_priv *gpio_leds_create(struct device *dev) 150 { 151 struct fwnode_handle *child; 152 struct gpio_leds_priv *priv; 153 int count, used, ret; 154 155 count = device_get_child_node_count(dev); 156 if (!count) 157 return ERR_PTR(-ENODEV); 158 159 priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL); 160 if (!priv) 161 return ERR_PTR(-ENOMEM); 162 priv->num_leds = count; 163 used = 0; 164 165 device_for_each_child_node(dev, child) { 166 struct gpio_led_data *led_dat = &priv->leds[used]; 167 struct gpio_led led = {}; 168 169 /* 170 * Acquire gpiod from DT with uninitialized label, which 171 * will be updated after LED class device is registered, 172 * Only then the final LED name is known. 173 */ 174 led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS, 175 NULL); 176 if (IS_ERR(led.gpiod)) { 177 dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get GPIO '%pfw'\n", 178 child); 179 fwnode_handle_put(child); 180 return ERR_CAST(led.gpiod); 181 } 182 183 led_dat->gpiod = led.gpiod; 184 185 led.default_state = led_init_default_state_get(child); 186 187 if (fwnode_property_present(child, "retain-state-suspended")) 188 led.retain_state_suspended = 1; 189 if (fwnode_property_present(child, "retain-state-shutdown")) 190 led.retain_state_shutdown = 1; 191 if (fwnode_property_present(child, "panic-indicator")) 192 led.panic_indicator = 1; 193 194 ret = create_gpio_led(&led, led_dat, dev, child, NULL); 195 if (ret < 0) { 196 fwnode_handle_put(child); 197 return ERR_PTR(ret); 198 } 199 /* Set gpiod label to match the corresponding LED name. */ 200 gpiod_set_consumer_name(led_dat->gpiod, 201 led_dat->cdev.dev->kobj.name); 202 used++; 203 } 204 priv->num_leds = used; 205 206 return priv; 207 } 208 209 static const struct of_device_id of_gpio_leds_match[] = { 210 { .compatible = "gpio-leds", }, 211 {}, 212 }; 213 214 MODULE_DEVICE_TABLE(of, of_gpio_leds_match); 215 216 static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx, 217 const struct gpio_led *template) 218 { 219 struct gpio_desc *gpiod; 220 int ret; 221 222 /* 223 * This means the LED does not come from the device tree 224 * or ACPI, so let's try just getting it by index from the 225 * device, this will hit the board file, if any and get 226 * the GPIO from there. 227 */ 228 gpiod = devm_gpiod_get_index_optional(dev, NULL, idx, GPIOD_OUT_LOW); 229 if (IS_ERR(gpiod)) 230 return gpiod; 231 if (gpiod) { 232 gpiod_set_consumer_name(gpiod, template->name); 233 return gpiod; 234 } 235 236 /* 237 * This is the legacy code path for platform code that 238 * still uses GPIO numbers. Ultimately we would like to get 239 * rid of this block completely. 240 */ 241 242 /* skip leds that aren't available */ 243 if (!gpio_is_valid(template->gpio)) 244 return ERR_PTR(-ENOENT); 245 246 ret = devm_gpio_request_one(dev, template->gpio, GPIOF_OUT_INIT_LOW, 247 template->name); 248 if (ret < 0) 249 return ERR_PTR(ret); 250 251 gpiod = gpio_to_desc(template->gpio); 252 if (!gpiod) 253 return ERR_PTR(-EINVAL); 254 255 if (template->active_low ^ gpiod_is_active_low(gpiod)) 256 gpiod_toggle_active_low(gpiod); 257 258 return gpiod; 259 } 260 261 static int gpio_led_probe(struct platform_device *pdev) 262 { 263 struct device *dev = &pdev->dev; 264 struct gpio_led_platform_data *pdata = dev_get_platdata(dev); 265 struct gpio_leds_priv *priv; 266 int i, ret; 267 268 if (pdata && pdata->num_leds) { 269 priv = devm_kzalloc(dev, struct_size(priv, leds, pdata->num_leds), GFP_KERNEL); 270 if (!priv) 271 return -ENOMEM; 272 273 priv->num_leds = pdata->num_leds; 274 for (i = 0; i < priv->num_leds; i++) { 275 const struct gpio_led *template = &pdata->leds[i]; 276 struct gpio_led_data *led_dat = &priv->leds[i]; 277 278 if (template->gpiod) 279 led_dat->gpiod = template->gpiod; 280 else 281 led_dat->gpiod = 282 gpio_led_get_gpiod(dev, i, template); 283 if (IS_ERR(led_dat->gpiod)) { 284 dev_info(dev, "Skipping unavailable LED gpio %d (%s)\n", 285 template->gpio, template->name); 286 continue; 287 } 288 289 ret = create_gpio_led(template, led_dat, dev, NULL, 290 pdata->gpio_blink_set); 291 if (ret < 0) 292 return ret; 293 } 294 } else { 295 priv = gpio_leds_create(dev); 296 if (IS_ERR(priv)) 297 return PTR_ERR(priv); 298 } 299 300 platform_set_drvdata(pdev, priv); 301 302 return 0; 303 } 304 305 static void gpio_led_shutdown(struct platform_device *pdev) 306 { 307 struct gpio_leds_priv *priv = platform_get_drvdata(pdev); 308 int i; 309 310 for (i = 0; i < priv->num_leds; i++) { 311 struct gpio_led_data *led = &priv->leds[i]; 312 313 if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN)) 314 gpio_led_set(&led->cdev, LED_OFF); 315 } 316 } 317 318 static struct platform_driver gpio_led_driver = { 319 .probe = gpio_led_probe, 320 .shutdown = gpio_led_shutdown, 321 .driver = { 322 .name = "leds-gpio", 323 .of_match_table = of_gpio_leds_match, 324 }, 325 }; 326 327 module_platform_driver(gpio_led_driver); 328 329 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 330 MODULE_DESCRIPTION("GPIO LED driver"); 331 MODULE_LICENSE("GPL"); 332 MODULE_ALIAS("platform:leds-gpio"); 333