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