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/workqueue.h> 18 19 #include <asm/gpio.h> 20 21 struct gpio_led_data { 22 struct led_classdev cdev; 23 unsigned gpio; 24 struct work_struct work; 25 u8 new_level; 26 u8 can_sleep; 27 u8 active_low; 28 int (*platform_gpio_blink_set)(unsigned gpio, 29 unsigned long *delay_on, unsigned long *delay_off); 30 }; 31 32 static void gpio_led_work(struct work_struct *work) 33 { 34 struct gpio_led_data *led_dat = 35 container_of(work, struct gpio_led_data, work); 36 37 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level); 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 = 44 container_of(led_cdev, struct gpio_led_data, cdev); 45 int level; 46 47 if (value == LED_OFF) 48 level = 0; 49 else 50 level = 1; 51 52 if (led_dat->active_low) 53 level = !level; 54 55 /* Setting GPIOs with I2C/etc requires a task context, and we don't 56 * seem to have a reliable way to know if we're already in one; so 57 * let's just assume the worst. 58 */ 59 if (led_dat->can_sleep) { 60 led_dat->new_level = level; 61 schedule_work(&led_dat->work); 62 } else 63 gpio_set_value(led_dat->gpio, level); 64 } 65 66 static int gpio_blink_set(struct led_classdev *led_cdev, 67 unsigned long *delay_on, unsigned long *delay_off) 68 { 69 struct gpio_led_data *led_dat = 70 container_of(led_cdev, struct gpio_led_data, cdev); 71 72 return led_dat->platform_gpio_blink_set(led_dat->gpio, delay_on, delay_off); 73 } 74 75 static int __devinit create_gpio_led(const struct gpio_led *template, 76 struct gpio_led_data *led_dat, struct device *parent, 77 int (*blink_set)(unsigned, unsigned long *, unsigned long *)) 78 { 79 int ret, state; 80 81 led_dat->gpio = -1; 82 83 /* skip leds that aren't available */ 84 if (!gpio_is_valid(template->gpio)) { 85 printk(KERN_INFO "Skipping unavailable LED gpio %d (%s)\n", 86 template->gpio, template->name); 87 return 0; 88 } 89 90 ret = gpio_request(template->gpio, template->name); 91 if (ret < 0) 92 return ret; 93 94 led_dat->cdev.name = template->name; 95 led_dat->cdev.default_trigger = template->default_trigger; 96 led_dat->gpio = template->gpio; 97 led_dat->can_sleep = gpio_cansleep(template->gpio); 98 led_dat->active_low = template->active_low; 99 if (blink_set) { 100 led_dat->platform_gpio_blink_set = blink_set; 101 led_dat->cdev.blink_set = gpio_blink_set; 102 } 103 led_dat->cdev.brightness_set = gpio_led_set; 104 if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) 105 state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low; 106 else 107 state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); 108 led_dat->cdev.brightness = state ? LED_FULL : LED_OFF; 109 if (!template->retain_state_suspended) 110 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 111 112 ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state); 113 if (ret < 0) 114 goto err; 115 116 INIT_WORK(&led_dat->work, gpio_led_work); 117 118 ret = led_classdev_register(parent, &led_dat->cdev); 119 if (ret < 0) 120 goto err; 121 122 return 0; 123 err: 124 gpio_free(led_dat->gpio); 125 return ret; 126 } 127 128 static void delete_gpio_led(struct gpio_led_data *led) 129 { 130 if (!gpio_is_valid(led->gpio)) 131 return; 132 led_classdev_unregister(&led->cdev); 133 cancel_work_sync(&led->work); 134 gpio_free(led->gpio); 135 } 136 137 #ifdef CONFIG_LEDS_GPIO_PLATFORM 138 static int __devinit gpio_led_probe(struct platform_device *pdev) 139 { 140 struct gpio_led_platform_data *pdata = pdev->dev.platform_data; 141 struct gpio_led_data *leds_data; 142 int i, ret = 0; 143 144 if (!pdata) 145 return -EBUSY; 146 147 leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds, 148 GFP_KERNEL); 149 if (!leds_data) 150 return -ENOMEM; 151 152 for (i = 0; i < pdata->num_leds; i++) { 153 ret = create_gpio_led(&pdata->leds[i], &leds_data[i], 154 &pdev->dev, pdata->gpio_blink_set); 155 if (ret < 0) 156 goto err; 157 } 158 159 platform_set_drvdata(pdev, leds_data); 160 161 return 0; 162 163 err: 164 for (i = i - 1; i >= 0; i--) 165 delete_gpio_led(&leds_data[i]); 166 167 kfree(leds_data); 168 169 return ret; 170 } 171 172 static int __devexit gpio_led_remove(struct platform_device *pdev) 173 { 174 int i; 175 struct gpio_led_platform_data *pdata = pdev->dev.platform_data; 176 struct gpio_led_data *leds_data; 177 178 leds_data = platform_get_drvdata(pdev); 179 180 for (i = 0; i < pdata->num_leds; i++) 181 delete_gpio_led(&leds_data[i]); 182 183 kfree(leds_data); 184 185 return 0; 186 } 187 188 static struct platform_driver gpio_led_driver = { 189 .probe = gpio_led_probe, 190 .remove = __devexit_p(gpio_led_remove), 191 .driver = { 192 .name = "leds-gpio", 193 .owner = THIS_MODULE, 194 }, 195 }; 196 197 MODULE_ALIAS("platform:leds-gpio"); 198 #endif /* CONFIG_LEDS_GPIO_PLATFORM */ 199 200 /* Code to create from OpenFirmware platform devices */ 201 #ifdef CONFIG_LEDS_GPIO_OF 202 #include <linux/of_platform.h> 203 #include <linux/of_gpio.h> 204 205 struct gpio_led_of_platform_data { 206 int num_leds; 207 struct gpio_led_data led_data[]; 208 }; 209 210 static int __devinit of_gpio_leds_probe(struct of_device *ofdev, 211 const struct of_device_id *match) 212 { 213 struct device_node *np = ofdev->node, *child; 214 struct gpio_led led; 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 memset(&led, 0, sizeof(led)); 230 for_each_child_of_node(np, child) { 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