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/kernel.h> 14 #include <linux/init.h> 15 #include <linux/platform_device.h> 16 #include <linux/leds.h> 17 #include <linux/slab.h> 18 #include <linux/workqueue.h> 19 20 #include <asm/gpio.h> 21 22 struct gpio_led_data { 23 struct led_classdev cdev; 24 unsigned gpio; 25 struct work_struct work; 26 u8 new_level; 27 u8 can_sleep; 28 u8 active_low; 29 u8 blinking; 30 int (*platform_gpio_blink_set)(unsigned gpio, int state, 31 unsigned long *delay_on, unsigned long *delay_off); 32 }; 33 34 static void gpio_led_work(struct work_struct *work) 35 { 36 struct gpio_led_data *led_dat = 37 container_of(work, struct gpio_led_data, work); 38 39 if (led_dat->blinking) { 40 led_dat->platform_gpio_blink_set(led_dat->gpio, 41 led_dat->new_level, 42 NULL, NULL); 43 led_dat->blinking = 0; 44 } else 45 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level); 46 } 47 48 static void gpio_led_set(struct led_classdev *led_cdev, 49 enum led_brightness value) 50 { 51 struct gpio_led_data *led_dat = 52 container_of(led_cdev, struct gpio_led_data, cdev); 53 int level; 54 55 if (value == LED_OFF) 56 level = 0; 57 else 58 level = 1; 59 60 if (led_dat->active_low) 61 level = !level; 62 63 /* Setting GPIOs with I2C/etc requires a task context, and we don't 64 * seem to have a reliable way to know if we're already in one; so 65 * let's just assume the worst. 66 */ 67 if (led_dat->can_sleep) { 68 led_dat->new_level = level; 69 schedule_work(&led_dat->work); 70 } else { 71 if (led_dat->blinking) { 72 led_dat->platform_gpio_blink_set(led_dat->gpio, level, 73 NULL, NULL); 74 led_dat->blinking = 0; 75 } else 76 gpio_set_value(led_dat->gpio, level); 77 } 78 } 79 80 static int gpio_blink_set(struct led_classdev *led_cdev, 81 unsigned long *delay_on, unsigned long *delay_off) 82 { 83 struct gpio_led_data *led_dat = 84 container_of(led_cdev, struct gpio_led_data, cdev); 85 86 led_dat->blinking = 1; 87 return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK, 88 delay_on, delay_off); 89 } 90 91 static int __devinit create_gpio_led(const struct gpio_led *template, 92 struct gpio_led_data *led_dat, struct device *parent, 93 int (*blink_set)(unsigned, int, unsigned long *, unsigned long *)) 94 { 95 int ret, state; 96 97 led_dat->gpio = -1; 98 99 /* skip leds that aren't available */ 100 if (!gpio_is_valid(template->gpio)) { 101 printk(KERN_INFO "Skipping unavailable LED gpio %d (%s)\n", 102 template->gpio, template->name); 103 return 0; 104 } 105 106 ret = gpio_request(template->gpio, template->name); 107 if (ret < 0) 108 return ret; 109 110 led_dat->cdev.name = template->name; 111 led_dat->cdev.default_trigger = template->default_trigger; 112 led_dat->gpio = template->gpio; 113 led_dat->can_sleep = gpio_cansleep(template->gpio); 114 led_dat->active_low = template->active_low; 115 led_dat->blinking = 0; 116 if (blink_set) { 117 led_dat->platform_gpio_blink_set = blink_set; 118 led_dat->cdev.blink_set = gpio_blink_set; 119 } 120 led_dat->cdev.brightness_set = gpio_led_set; 121 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) 122 state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low; 123 else 124 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); 125 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF; 126 if (!template->retain_state_suspended) 127 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 128 129 ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state); 130 if (ret < 0) 131 goto err; 132 133 INIT_WORK(&led_dat->work, gpio_led_work); 134 135 ret = led_classdev_register(parent, &led_dat->cdev); 136 if (ret < 0) 137 goto err; 138 139 return 0; 140 err: 141 gpio_free(led_dat->gpio); 142 return ret; 143 } 144 145 static void delete_gpio_led(struct gpio_led_data *led) 146 { 147 if (!gpio_is_valid(led->gpio)) 148 return; 149 led_classdev_unregister(&led->cdev); 150 cancel_work_sync(&led->work); 151 gpio_free(led->gpio); 152 } 153 154 #ifdef CONFIG_LEDS_GPIO_PLATFORM 155 static int __devinit gpio_led_probe(struct platform_device *pdev) 156 { 157 struct gpio_led_platform_data *pdata = pdev->dev.platform_data; 158 struct gpio_led_data *leds_data; 159 int i, ret = 0; 160 161 if (!pdata) 162 return -EBUSY; 163 164 leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds, 165 GFP_KERNEL); 166 if (!leds_data) 167 return -ENOMEM; 168 169 for (i = 0; i < pdata->num_leds; i++) { 170 ret = create_gpio_led(&pdata->leds[i], &leds_data[i], 171 &pdev->dev, pdata->gpio_blink_set); 172 if (ret < 0) 173 goto err; 174 } 175 176 platform_set_drvdata(pdev, leds_data); 177 178 return 0; 179 180 err: 181 for (i = i - 1; i >= 0; i--) 182 delete_gpio_led(&leds_data[i]); 183 184 kfree(leds_data); 185 186 return ret; 187 } 188 189 static int __devexit gpio_led_remove(struct platform_device *pdev) 190 { 191 int i; 192 struct gpio_led_platform_data *pdata = pdev->dev.platform_data; 193 struct gpio_led_data *leds_data; 194 195 leds_data = platform_get_drvdata(pdev); 196 197 for (i = 0; i < pdata->num_leds; i++) 198 delete_gpio_led(&leds_data[i]); 199 200 kfree(leds_data); 201 202 return 0; 203 } 204 205 static struct platform_driver gpio_led_driver = { 206 .probe = gpio_led_probe, 207 .remove = __devexit_p(gpio_led_remove), 208 .driver = { 209 .name = "leds-gpio", 210 .owner = THIS_MODULE, 211 }, 212 }; 213 214 MODULE_ALIAS("platform:leds-gpio"); 215 #endif /* CONFIG_LEDS_GPIO_PLATFORM */ 216 217 /* Code to create from OpenFirmware platform devices */ 218 #ifdef CONFIG_LEDS_GPIO_OF 219 #include <linux/of_platform.h> 220 #include <linux/of_gpio.h> 221 222 struct gpio_led_of_platform_data { 223 int num_leds; 224 struct gpio_led_data led_data[]; 225 }; 226 227 static int __devinit of_gpio_leds_probe(struct platform_device *ofdev, 228 const struct of_device_id *match) 229 { 230 struct device_node *np = ofdev->dev.of_node, *child; 231 struct gpio_led_of_platform_data *pdata; 232 int count = 0, ret; 233 234 /* count LEDs defined by this device, so we know how much to allocate */ 235 for_each_child_of_node(np, child) 236 count++; 237 if (!count) 238 return 0; /* or ENODEV? */ 239 240 pdata = kzalloc(sizeof(*pdata) + sizeof(struct gpio_led_data) * count, 241 GFP_KERNEL); 242 if (!pdata) 243 return -ENOMEM; 244 245 for_each_child_of_node(np, child) { 246 struct gpio_led led = {}; 247 enum of_gpio_flags flags; 248 const char *state; 249 250 led.gpio = of_get_gpio_flags(child, 0, &flags); 251 led.active_low = flags & OF_GPIO_ACTIVE_LOW; 252 led.name = of_get_property(child, "label", NULL) ? : child->name; 253 led.default_trigger = 254 of_get_property(child, "linux,default-trigger", NULL); 255 state = of_get_property(child, "default-state", NULL); 256 if (state) { 257 if (!strcmp(state, "keep")) 258 led.default_state = LEDS_GPIO_DEFSTATE_KEEP; 259 else if(!strcmp(state, "on")) 260 led.default_state = LEDS_GPIO_DEFSTATE_ON; 261 else 262 led.default_state = LEDS_GPIO_DEFSTATE_OFF; 263 } 264 265 ret = create_gpio_led(&led, &pdata->led_data[pdata->num_leds++], 266 &ofdev->dev, NULL); 267 if (ret < 0) { 268 of_node_put(child); 269 goto err; 270 } 271 } 272 273 dev_set_drvdata(&ofdev->dev, pdata); 274 275 return 0; 276 277 err: 278 for (count = pdata->num_leds - 2; count >= 0; count--) 279 delete_gpio_led(&pdata->led_data[count]); 280 281 kfree(pdata); 282 283 return ret; 284 } 285 286 static int __devexit of_gpio_leds_remove(struct platform_device *ofdev) 287 { 288 struct gpio_led_of_platform_data *pdata = dev_get_drvdata(&ofdev->dev); 289 int i; 290 291 for (i = 0; i < pdata->num_leds; i++) 292 delete_gpio_led(&pdata->led_data[i]); 293 294 kfree(pdata); 295 296 dev_set_drvdata(&ofdev->dev, NULL); 297 298 return 0; 299 } 300 301 static const struct of_device_id of_gpio_leds_match[] = { 302 { .compatible = "gpio-leds", }, 303 {}, 304 }; 305 306 static struct of_platform_driver of_gpio_leds_driver = { 307 .driver = { 308 .name = "of_gpio_leds", 309 .owner = THIS_MODULE, 310 .of_match_table = of_gpio_leds_match, 311 }, 312 .probe = of_gpio_leds_probe, 313 .remove = __devexit_p(of_gpio_leds_remove), 314 }; 315 #endif 316 317 static int __init gpio_led_init(void) 318 { 319 int ret = 0; 320 321 #ifdef CONFIG_LEDS_GPIO_PLATFORM 322 ret = platform_driver_register(&gpio_led_driver); 323 if (ret) 324 return ret; 325 #endif 326 #ifdef CONFIG_LEDS_GPIO_OF 327 ret = of_register_platform_driver(&of_gpio_leds_driver); 328 #endif 329 #ifdef CONFIG_LEDS_GPIO_PLATFORM 330 if (ret) 331 platform_driver_unregister(&gpio_led_driver); 332 #endif 333 334 return ret; 335 } 336 337 static void __exit gpio_led_exit(void) 338 { 339 #ifdef CONFIG_LEDS_GPIO_PLATFORM 340 platform_driver_unregister(&gpio_led_driver); 341 #endif 342 #ifdef CONFIG_LEDS_GPIO_OF 343 of_unregister_platform_driver(&of_gpio_leds_driver); 344 #endif 345 } 346 347 module_init(gpio_led_init); 348 module_exit(gpio_led_exit); 349 350 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 351 MODULE_DESCRIPTION("GPIO LED driver"); 352 MODULE_LICENSE("GPL"); 353