leds-gpio.c 7.5 KB
Newer Older
1 2 3 4 5
/*
 * LEDs driver for GPIOs
 *
 * Copyright (C) 2007 8D Technologies inc.
 * Raphael Assenat <raph@8d.com>
6
 * Copyright (C) 2008 Freescale Semiconductor, Inc.
7 8 9 10 11 12 13 14 15
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
16
#include <linux/gpio.h>
17
#include <linux/leds.h>
18
#include <linux/of.h>
19 20
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
21
#include <linux/slab.h>
22
#include <linux/workqueue.h>
23
#include <linux/module.h>
24
#include <linux/err.h>
25

26 27 28
struct gpio_led_data {
	struct led_classdev cdev;
	unsigned gpio;
29 30 31
	struct work_struct work;
	u8 new_level;
	u8 can_sleep;
32
	u8 active_low;
33 34
	u8 blinking;
	int (*platform_gpio_blink_set)(unsigned gpio, int state,
35
			unsigned long *delay_on, unsigned long *delay_off);
36 37
};

38 39 40 41 42
static void gpio_led_work(struct work_struct *work)
{
	struct gpio_led_data	*led_dat =
		container_of(work, struct gpio_led_data, work);

43 44 45 46 47 48 49
	if (led_dat->blinking) {
		led_dat->platform_gpio_blink_set(led_dat->gpio,
						 led_dat->new_level,
						 NULL, NULL);
		led_dat->blinking = 0;
	} else
		gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
50
}
51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66

static void gpio_led_set(struct led_classdev *led_cdev,
	enum led_brightness value)
{
	struct gpio_led_data *led_dat =
		container_of(led_cdev, struct gpio_led_data, cdev);
	int level;

	if (value == LED_OFF)
		level = 0;
	else
		level = 1;

	if (led_dat->active_low)
		level = !level;

67 68 69 70
	/* Setting GPIOs with I2C/etc requires a task context, and we don't
	 * seem to have a reliable way to know if we're already in one; so
	 * let's just assume the worst.
	 */
71
	if (led_dat->can_sleep) {
72 73
		led_dat->new_level = level;
		schedule_work(&led_dat->work);
74 75 76 77 78 79 80 81
	} else {
		if (led_dat->blinking) {
			led_dat->platform_gpio_blink_set(led_dat->gpio, level,
							 NULL, NULL);
			led_dat->blinking = 0;
		} else
			gpio_set_value(led_dat->gpio, level);
	}
82 83
}

84 85 86 87 88 89
static int gpio_blink_set(struct led_classdev *led_cdev,
	unsigned long *delay_on, unsigned long *delay_off)
{
	struct gpio_led_data *led_dat =
		container_of(led_cdev, struct gpio_led_data, cdev);

90 91 92
	led_dat->blinking = 1;
	return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK,
						delay_on, delay_off);
93 94
}

95
static int create_gpio_led(const struct gpio_led *template,
96
	struct gpio_led_data *led_dat, struct device *parent,
97
	int (*blink_set)(unsigned, int, unsigned long *, unsigned long *))
98
{
99
	int ret, state;
100

101 102
	led_dat->gpio = -1;

103 104
	/* skip leds that aren't available */
	if (!gpio_is_valid(template->gpio)) {
105
		dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
106
				template->gpio, template->name);
107
		return 0;
108 109
	}

110 111 112 113
	ret = devm_gpio_request(parent, template->gpio, template->name);
	if (ret < 0)
		return ret;

114 115 116 117 118
	led_dat->cdev.name = template->name;
	led_dat->cdev.default_trigger = template->default_trigger;
	led_dat->gpio = template->gpio;
	led_dat->can_sleep = gpio_cansleep(template->gpio);
	led_dat->active_low = template->active_low;
119
	led_dat->blinking = 0;
120 121 122 123 124
	if (blink_set) {
		led_dat->platform_gpio_blink_set = blink_set;
		led_dat->cdev.blink_set = gpio_blink_set;
	}
	led_dat->cdev.brightness_set = gpio_led_set;
125
	if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
126
		state = !!gpio_get_value_cansleep(led_dat->gpio) ^ led_dat->active_low;
127 128 129
	else
		state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
	led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
130 131
	if (!template->retain_state_suspended)
		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
132

133
	ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
134
	if (ret < 0)
135 136
		return ret;

137 138 139 140
	INIT_WORK(&led_dat->work, gpio_led_work);

	ret = led_classdev_register(parent, &led_dat->cdev);
	if (ret < 0)
141
		return ret;
142 143 144 145 146 147

	return 0;
}

static void delete_gpio_led(struct gpio_led_data *led)
{
148 149
	if (!gpio_is_valid(led->gpio))
		return;
150 151 152 153
	led_classdev_unregister(&led->cdev);
	cancel_work_sync(&led->work);
}

154 155 156 157
struct gpio_leds_priv {
	int num_leds;
	struct gpio_led_data leds[];
};
158

159
static inline int sizeof_gpio_leds_priv(int num_leds)
160
{
161 162
	return sizeof(struct gpio_leds_priv) +
		(sizeof(struct gpio_led_data) * num_leds);
163 164
}

165
/* Code to create from OpenFirmware platform devices */
166
#ifdef CONFIG_OF_GPIO
167
static struct gpio_leds_priv *gpio_leds_create_of(struct platform_device *pdev)
168
{
169 170
	struct device_node *np = pdev->dev.of_node, *child;
	struct gpio_leds_priv *priv;
171
	int count, ret;
172

173
	/* count LEDs in this device, so we know how much to allocate */
174
	count = of_get_available_child_count(np);
175
	if (!count)
176 177
		return ERR_PTR(-ENODEV);

178
	for_each_available_child_of_node(np, child)
179 180
		if (of_get_gpio(child, 0) == -EPROBE_DEFER)
			return ERR_PTR(-EPROBE_DEFER);
181

182 183
	priv = devm_kzalloc(&pdev->dev, sizeof_gpio_leds_priv(count),
			GFP_KERNEL);
184
	if (!priv)
185
		return ERR_PTR(-ENOMEM);
186

187
	for_each_available_child_of_node(np, child) {
188
		struct gpio_led led = {};
189
		enum of_gpio_flags flags;
190
		const char *state;
191 192 193 194 195 196

		led.gpio = of_get_gpio_flags(child, 0, &flags);
		led.active_low = flags & OF_GPIO_ACTIVE_LOW;
		led.name = of_get_property(child, "label", NULL) ? : child->name;
		led.default_trigger =
			of_get_property(child, "linux,default-trigger", NULL);
197 198 199 200
		state = of_get_property(child, "default-state", NULL);
		if (state) {
			if (!strcmp(state, "keep"))
				led.default_state = LEDS_GPIO_DEFSTATE_KEEP;
201
			else if (!strcmp(state, "on"))
202 203 204 205
				led.default_state = LEDS_GPIO_DEFSTATE_ON;
			else
				led.default_state = LEDS_GPIO_DEFSTATE_OFF;
		}
206

207 208
		ret = create_gpio_led(&led, &priv->leds[priv->num_leds++],
				      &pdev->dev, NULL);
209 210 211 212 213 214
		if (ret < 0) {
			of_node_put(child);
			goto err;
		}
	}

215
	return priv;
216 217

err:
218 219
	for (count = priv->num_leds - 2; count >= 0; count--)
		delete_gpio_led(&priv->leds[count]);
220
	return ERR_PTR(-ENODEV);
221
}
222

223 224 225 226
static const struct of_device_id of_gpio_leds_match[] = {
	{ .compatible = "gpio-leds", },
	{},
};
227
#else /* CONFIG_OF_GPIO */
228
static struct gpio_leds_priv *gpio_leds_create_of(struct platform_device *pdev)
229
{
230
	return ERR_PTR(-ENODEV);
231
}
232
#endif /* CONFIG_OF_GPIO */
233

234

235
static int gpio_led_probe(struct platform_device *pdev)
236
{
J
Jingoo Han 已提交
237
	struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);
238 239 240
	struct gpio_leds_priv *priv;
	int i, ret = 0;

241

242
	if (pdata && pdata->num_leds) {
243 244 245
		priv = devm_kzalloc(&pdev->dev,
				sizeof_gpio_leds_priv(pdata->num_leds),
					GFP_KERNEL);
246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262
		if (!priv)
			return -ENOMEM;

		priv->num_leds = pdata->num_leds;
		for (i = 0; i < priv->num_leds; i++) {
			ret = create_gpio_led(&pdata->leds[i],
					      &priv->leds[i],
					      &pdev->dev, pdata->gpio_blink_set);
			if (ret < 0) {
				/* On failure: unwind the led creations */
				for (i = i - 1; i >= 0; i--)
					delete_gpio_led(&priv->leds[i]);
				return ret;
			}
		}
	} else {
		priv = gpio_leds_create_of(pdev);
263 264
		if (IS_ERR(priv))
			return PTR_ERR(priv);
265 266 267 268 269
	}

	platform_set_drvdata(pdev, priv);

	return 0;
270 271
}

272
static int gpio_led_remove(struct platform_device *pdev)
273
{
274
	struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
275 276
	int i;

277 278
	for (i = 0; i < priv->num_leds; i++)
		delete_gpio_led(&priv->leds[i]);
279 280 281 282

	return 0;
}

283 284
static struct platform_driver gpio_led_driver = {
	.probe		= gpio_led_probe,
285
	.remove		= gpio_led_remove,
286 287 288
	.driver		= {
		.name	= "leds-gpio",
		.owner	= THIS_MODULE,
289
		.of_match_table = of_match_ptr(of_gpio_leds_match),
290 291
	},
};
292

293
module_platform_driver(gpio_led_driver);
294 295

MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");
296 297
MODULE_DESCRIPTION("GPIO LED driver");
MODULE_LICENSE("GPL");
298
MODULE_ALIAS("platform:leds-gpio");
新手
引导
客服 返回
顶部