1 /* 2 * LEDs driver for GPIOs 3 * 4 * Copyright (C) 2007 8D Technologies inc. 5 * Raphael Assenat <raph@8d.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 */ 12 #include <linux/kernel.h> 13 #include <linux/init.h> 14 #include <linux/platform_device.h> 15 #include <linux/leds.h> 16 #include <linux/workqueue.h> 17 18 #include <asm/gpio.h> 19 20 struct gpio_led_data { 21 struct led_classdev cdev; 22 unsigned gpio; 23 struct work_struct work; 24 u8 new_level; 25 u8 can_sleep; 26 u8 active_low; 27 int (*platform_gpio_blink_set)(unsigned gpio, 28 unsigned long *delay_on, unsigned long *delay_off); 29 }; 30 31 static void gpio_led_work(struct work_struct *work) 32 { 33 struct gpio_led_data *led_dat = 34 container_of(work, struct gpio_led_data, work); 35 36 gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level); 37 } 38 39 static void gpio_led_set(struct led_classdev *led_cdev, 40 enum led_brightness value) 41 { 42 struct gpio_led_data *led_dat = 43 container_of(led_cdev, struct gpio_led_data, cdev); 44 int level; 45 46 if (value == LED_OFF) 47 level = 0; 48 else 49 level = 1; 50 51 if (led_dat->active_low) 52 level = !level; 53 54 /* Setting GPIOs with I2C/etc requires a task context, and we don't 55 * seem to have a reliable way to know if we're already in one; so 56 * let's just assume the worst. 57 */ 58 if (led_dat->can_sleep) { 59 led_dat->new_level = level; 60 schedule_work(&led_dat->work); 61 } else 62 gpio_set_value(led_dat->gpio, level); 63 } 64 65 static int gpio_blink_set(struct led_classdev *led_cdev, 66 unsigned long *delay_on, unsigned long *delay_off) 67 { 68 struct gpio_led_data *led_dat = 69 container_of(led_cdev, struct gpio_led_data, cdev); 70 71 return led_dat->platform_gpio_blink_set(led_dat->gpio, delay_on, delay_off); 72 } 73 74 static int gpio_led_probe(struct platform_device *pdev) 75 { 76 struct gpio_led_platform_data *pdata = pdev->dev.platform_data; 77 struct gpio_led *cur_led; 78 struct gpio_led_data *leds_data, *led_dat; 79 int i, ret = 0; 80 81 if (!pdata) 82 return -EBUSY; 83 84 leds_data = kzalloc(sizeof(struct gpio_led_data) * pdata->num_leds, 85 GFP_KERNEL); 86 if (!leds_data) 87 return -ENOMEM; 88 89 for (i = 0; i < pdata->num_leds; i++) { 90 cur_led = &pdata->leds[i]; 91 led_dat = &leds_data[i]; 92 93 ret = gpio_request(cur_led->gpio, cur_led->name); 94 if (ret < 0) 95 goto err; 96 97 led_dat->cdev.name = cur_led->name; 98 led_dat->cdev.default_trigger = cur_led->default_trigger; 99 led_dat->gpio = cur_led->gpio; 100 led_dat->can_sleep = gpio_cansleep(cur_led->gpio); 101 led_dat->active_low = cur_led->active_low; 102 if (pdata->gpio_blink_set) { 103 led_dat->platform_gpio_blink_set = pdata->gpio_blink_set; 104 led_dat->cdev.blink_set = gpio_blink_set; 105 } 106 led_dat->cdev.brightness_set = gpio_led_set; 107 led_dat->cdev.brightness = LED_OFF; 108 led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; 109 110 gpio_direction_output(led_dat->gpio, led_dat->active_low); 111 112 INIT_WORK(&led_dat->work, gpio_led_work); 113 114 ret = led_classdev_register(&pdev->dev, &led_dat->cdev); 115 if (ret < 0) { 116 gpio_free(led_dat->gpio); 117 goto err; 118 } 119 } 120 121 platform_set_drvdata(pdev, leds_data); 122 123 return 0; 124 125 err: 126 if (i > 0) { 127 for (i = i - 1; i >= 0; i--) { 128 led_classdev_unregister(&leds_data[i].cdev); 129 cancel_work_sync(&leds_data[i].work); 130 gpio_free(leds_data[i].gpio); 131 } 132 } 133 134 kfree(leds_data); 135 136 return ret; 137 } 138 139 static int __devexit gpio_led_remove(struct platform_device *pdev) 140 { 141 int i; 142 struct gpio_led_platform_data *pdata = pdev->dev.platform_data; 143 struct gpio_led_data *leds_data; 144 145 leds_data = platform_get_drvdata(pdev); 146 147 for (i = 0; i < pdata->num_leds; i++) { 148 led_classdev_unregister(&leds_data[i].cdev); 149 cancel_work_sync(&leds_data[i].work); 150 gpio_free(leds_data[i].gpio); 151 } 152 153 kfree(leds_data); 154 155 return 0; 156 } 157 158 static struct platform_driver gpio_led_driver = { 159 .probe = gpio_led_probe, 160 .remove = __devexit_p(gpio_led_remove), 161 .driver = { 162 .name = "leds-gpio", 163 .owner = THIS_MODULE, 164 }, 165 }; 166 167 static int __init gpio_led_init(void) 168 { 169 return platform_driver_register(&gpio_led_driver); 170 } 171 172 static void __exit gpio_led_exit(void) 173 { 174 platform_driver_unregister(&gpio_led_driver); 175 } 176 177 module_init(gpio_led_init); 178 module_exit(gpio_led_exit); 179 180 MODULE_AUTHOR("Raphael Assenat <raph@8d.com>"); 181 MODULE_DESCRIPTION("GPIO LED driver"); 182 MODULE_LICENSE("GPL"); 183 MODULE_ALIAS("platform:leds-gpio"); 184