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