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; 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 led_dat->cdev.brightness = LED_OFF; 103 if (!template->retain_state_suspended) 104 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 105 106 ret = gpio_direction_output(led_dat->gpio, led_dat->active_low); 107 if (ret < 0) 108 goto err; 109 110 INIT_WORK(&led_dat->work, gpio_led_work); 111 112 ret = led_classdev_register(parent, &led_dat->cdev); 113 if (ret < 0) 114 goto err; 115 116 return 0; 117 err: 118 gpio_free(led_dat->gpio); 119 return ret; 120 } 121 122 static void delete_gpio_led(struct gpio_led_data *led) 123 { 124 if (!gpio_is_valid(led->gpio)) 125 return; 126 led_classdev_unregister(&led->cdev); 127 cancel_work_sync(&led->work); 128 gpio_free(led->gpio); 129 } 130 131 #ifdef CONFIG_LEDS_GPIO_PLATFORM 132 static int gpio_led_probe(struct platform_device *pdev) 133 { 134 struct gpio_led_platform_data *pdata = pdev->dev.platform_data; 135 struct gpio_led_data *leds_data; 136 int i, ret = 0; 137 138 if (!pdata) 139 return -EBUSY; 140 141 leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds, 142 GFP_KERNEL); 143 if (!leds_data) 144 return -ENOMEM; 145 146 for (i = 0; i < pdata->num_leds; i++) { 147 ret = create_gpio_led(&pdata->leds[i], &leds_data[i], 148 &pdev->dev, pdata->gpio_blink_set); 149 if (ret < 0) 150 goto err; 151 } 152 153 platform_set_drvdata(pdev, leds_data); 154 155 return 0; 156 157 err: 158 for (i = i - 1; i >= 0; i--) 159 delete_gpio_led(&leds_data[i]); 160 161 kfree(leds_data); 162 163 return ret; 164 } 165 166 static int __devexit gpio_led_remove(struct platform_device *pdev) 167 { 168 int i; 169 struct gpio_led_platform_data *pdata = pdev->dev.platform_data; 170 struct gpio_led_data *leds_data; 171 172 leds_data = platform_get_drvdata(pdev); 173 174 for (i = 0; i < pdata->num_leds; i++) 175 delete_gpio_led(&leds_data[i]); 176 177 kfree(leds_data); 178 179 return 0; 180 } 181 182 static struct platform_driver gpio_led_driver = { 183 .probe = gpio_led_probe, 184 .remove = __devexit_p(gpio_led_remove), 185 .driver = { 186 .name = "leds-gpio", 187 .owner = THIS_MODULE, 188 }, 189 }; 190 191 MODULE_ALIAS("platform:leds-gpio"); 192 #endif /* CONFIG_LEDS_GPIO_PLATFORM */ 193 194 /* Code to create from OpenFirmware platform devices */ 195 #ifdef CONFIG_LEDS_GPIO_OF 196 #include <linux/of_platform.h> 197 #include <linux/of_gpio.h> 198 199 struct gpio_led_of_platform_data { 200 int num_leds; 201 struct gpio_led_data led_data[]; 202 }; 203 204 static int __devinit of_gpio_leds_probe(struct of_device *ofdev, 205 const struct of_device_id *match) 206 { 207 struct device_node *np = ofdev->node, *child; 208 struct gpio_led led; 209 struct gpio_led_of_platform_data *pdata; 210 int count = 0, ret; 211 212 /* count LEDs defined by this device, so we know how much to allocate */ 213 for_each_child_of_node(np, child) 214 count++; 215 if (!count) 216 return 0; /* or ENODEV? */ 217 218 pdata = kzalloc(sizeof(*pdata) + sizeof(struct gpio_led_data) * count, 219 GFP_KERNEL); 220 if (!pdata) 221 return -ENOMEM; 222 223 memset(&led, 0, sizeof(led)); 224 for_each_child_of_node(np, child) { 225 enum of_gpio_flags flags; 226 227 led.gpio = of_get_gpio_flags(child, 0, &flags); 228 led.active_low = flags & OF_GPIO_ACTIVE_LOW; 229 led.name = of_get_property(child, "label", NULL) ? : child->name; 230 led.default_trigger = 231 of_get_property(child, "linux,default-trigger", NULL); 232 233 ret = create_gpio_led(&led, &pdata->led_data[pdata->num_leds++], 234 &ofdev->dev, NULL); 235 if (ret < 0) { 236 of_node_put(child); 237 goto err; 238 } 239 } 240 241 dev_set_drvdata(&ofdev->dev, pdata); 242 243 return 0; 244 245 err: 246 for (count = pdata->num_leds - 2; count >= 0; count--) 247 delete_gpio_led(&pdata->led_data[count]); 248 249 kfree(pdata); 250 251 return ret; 252 } 253 254 static int __devexit of_gpio_leds_remove(struct of_device *ofdev) 255 { 256 struct gpio_led_of_platform_data *pdata = dev_get_drvdata(&ofdev->dev); 257 int i; 258 259 for (i = 0; i < pdata->num_leds; i++) 260 delete_gpio_led(&pdata->led_data[i]); 261 262 kfree(pdata); 263 264 dev_set_drvdata(&ofdev->dev, NULL); 265 266 return 0; 267 } 268 269 static const struct of_device_id of_gpio_leds_match[] = { 270 { .compatible = "gpio-leds", }, 271 {}, 272 }; 273 274 static struct of_platform_driver of_gpio_leds_driver = { 275 .driver = { 276 .name = "of_gpio_leds", 277 .owner = THIS_MODULE, 278 }, 279 .match_table = of_gpio_leds_match, 280 .probe = of_gpio_leds_probe, 281 .remove = __devexit_p(of_gpio_leds_remove), 282 }; 283 #endif 284 285 static int __init gpio_led_init(void) 286 { 287 int ret; 288 289 #ifdef CONFIG_LEDS_GPIO_PLATFORM 290 ret = platform_driver_register(&gpio_led_driver); 291 if (ret) 292 return ret; 293 #endif 294 #ifdef CONFIG_LEDS_GPIO_OF 295 ret = of_register_platform_driver(&of_gpio_leds_driver); 296 #endif 297 #ifdef CONFIG_LEDS_GPIO_PLATFORM 298 if (ret) 299 platform_driver_unregister(&gpio_led_driver); 300 #endif 301 302 return ret; 303 } 304 305 static void __exit gpio_led_exit(void) 306 { 307 #ifdef CONFIG_LEDS_GPIO_PLATFORM 308 platform_driver_unregister(&gpio_led_driver); 309 #endif 310 #ifdef CONFIG_LEDS_GPIO_OF 311 of_unregister_platform_driver(&of_gpio_leds_driver); 312 #endif 313 } 314 315 module_init(gpio_led_init); 316 module_exit(gpio_led_exit); 317 318 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>"); 319 MODULE_DESCRIPTION("GPIO LED driver"); 320 MODULE_LICENSE("GPL"); 321