drivers/leds/leds-pm8xxx.c

/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/workqueue.h>

#include <linux/mfd/pm8xxx/core.h>
#include <linux/leds-pm8xxx.h>

#define SSBI_REG_ADDR_DRV_KEYPAD	0x48
#define PM8XXX_DRV_KEYPAD_BL_MASK	0xf0
#define PM8XXX_DRV_KEYPAD_BL_SHIFT	0x04

#define SSBI_REG_ADDR_FLASH_DRV0        0x49
#define PM8XXX_DRV_FLASH_MASK           0xf0
#define PM8XXX_DRV_FLASH_SHIFT          0x04

#define SSBI_REG_ADDR_FLASH_DRV1        0xFB

#define SSBI_REG_ADDR_LED_CTRL_BASE	0x131
#define SSBI_REG_ADDR_LED_CTRL(n)	(SSBI_REG_ADDR_LED_CTRL_BASE + (n))
#define PM8XXX_DRV_LED_CTRL_MASK	0xf8
#define PM8XXX_DRV_LED_CTRL_SHIFT	0x03

#define MAX_FLASH_LED_CURRENT	300
#define MAX_LC_LED_CURRENT	40
#define MAX_KP_BL_LED_CURRENT	300

#define MAX_KEYPAD_BL_LEVEL	(1 << 4)
#define MAX_LED_DRV_LEVEL	20 /* 2 * 20 mA */

#define PM8XXX_LED_OFFSET(id) ((id) - PM8XXX_ID_LED_0)

#define MAX_KB_LED_BRIGHTNESS		15
#define MAX_LC_LED_BRIGHTNESS		20
#define MAX_FLASH_LED_BRIGHTNESS	15

/**
 * struct pm8xxx_led_data - internal led data structure
 * @led_classdev - led class device
 * @id - led index
 * @led_brightness - led brightness levels
 * @work - workqueue for led
 * @lock - to protect the transactions
 * @reg - cached value of led register
 */
struct pm8xxx_led_data {
	struct led_classdev	cdev;
	int			id;
	u8			reg;
	enum led_brightness	brightness;
	struct device		*dev;
	struct work_struct	work;
	struct mutex		lock;
};

static void led_kp_set(struct pm8xxx_led_data *led, enum led_brightness value)
{
	int rc;
	u8 level;

	level = (value << PM8XXX_DRV_KEYPAD_BL_SHIFT) &
				 PM8XXX_DRV_KEYPAD_BL_MASK;

	led->reg &= ~PM8XXX_DRV_KEYPAD_BL_MASK;
	led->reg |= level;

	rc = pm8xxx_writeb(led->dev->parent, SSBI_REG_ADDR_DRV_KEYPAD,
								led->reg);
	if (rc < 0)
		dev_err(led->cdev.dev,
			"can't set keypad backlight level rc=%d\n", rc);
}

static void led_lc_set(struct pm8xxx_led_data *led, enum led_brightness value)
{
	int rc, offset;
	u8 level;

	level = (value << PM8XXX_DRV_LED_CTRL_SHIFT) &
				PM8XXX_DRV_LED_CTRL_MASK;

	offset = PM8XXX_LED_OFFSET(led->id);

	led->reg &= ~PM8XXX_DRV_LED_CTRL_MASK;
	led->reg |= level;

	rc = pm8xxx_writeb(led->dev->parent, SSBI_REG_ADDR_LED_CTRL(offset),
								led->reg);
	if (rc)
		dev_err(led->cdev.dev, "can't set (%d) led value rc=%d\n",
				led->id, rc);
}

static void
led_flash_set(struct pm8xxx_led_data *led, enum led_brightness value)
{
	int rc;
	u8 level;
	u16 reg_addr;

	level = (value << PM8XXX_DRV_FLASH_SHIFT) &
				 PM8XXX_DRV_FLASH_MASK;

	led->reg &= ~PM8XXX_DRV_FLASH_MASK;
	led->reg |= level;

	if (led->id == PM8XXX_ID_FLASH_LED_0)
		reg_addr = SSBI_REG_ADDR_FLASH_DRV0;
	else
		reg_addr = SSBI_REG_ADDR_FLASH_DRV1;

	rc = pm8xxx_writeb(led->dev->parent, reg_addr, led->reg);
	if (rc < 0)
		dev_err(led->cdev.dev, "can't set flash led%d level rc=%d\n",
			 led->id, rc);
}

static void pm8xxx_led_work(struct work_struct *work)
{
	struct pm8xxx_led_data *led = container_of(work,
					 struct pm8xxx_led_data, work);

	mutex_lock(&led->lock);

	switch (led->id) {
	case PM8XXX_ID_LED_KB_LIGHT:
		led_kp_set(led, led->brightness);
	break;
	case PM8XXX_ID_LED_0:
	case PM8XXX_ID_LED_1:
	case PM8XXX_ID_LED_2:
		led_lc_set(led, led->brightness);
	break;
	case PM8XXX_ID_FLASH_LED_0:
	case PM8XXX_ID_FLASH_LED_1:
		led_flash_set(led, led->brightness);
	break;
	}

	mutex_unlock(&led->lock);
}

static void pm8xxx_led_set(struct led_classdev *led_cdev,
	enum led_brightness value)
{
	struct pm8xxx_led_data *led;

	led = container_of(led_cdev, struct pm8xxx_led_data, cdev);

	led->brightness = value;
	schedule_work(&led->work);
}

static enum led_brightness pm8xxx_led_get(struct led_classdev *led_cdev)
{
	struct pm8xxx_led_data *led;

	led = container_of(led_cdev, struct pm8xxx_led_data, cdev);

	return led->brightness;
}

static int __devinit get_max_brightness(enum pm8xxx_leds id)
{
	switch (id) {
	case PM8XXX_ID_LED_KB_LIGHT:
		return MAX_KB_LED_BRIGHTNESS;
	case PM8XXX_ID_LED_0:
	case PM8XXX_ID_LED_1:
	case PM8XXX_ID_LED_2:
		return MAX_LC_LED_BRIGHTNESS;
	case PM8XXX_ID_FLASH_LED_0:
	case PM8XXX_ID_FLASH_LED_1:
		return MAX_FLASH_LED_CURRENT;
	default:
		return 0;
	}
}

static int __devinit get_init_value(struct pm8xxx_led_data *led, u8 *val)
{
	int rc, offset;
	u16 addr;

	switch (led->id) {
	case PM8XXX_ID_LED_KB_LIGHT:
		addr = SSBI_REG_ADDR_DRV_KEYPAD;
		break;
	case PM8XXX_ID_LED_0:
	case PM8XXX_ID_LED_1:
	case PM8XXX_ID_LED_2:
		offset = PM8XXX_LED_OFFSET(led->id);
		addr = SSBI_REG_ADDR_LED_CTRL(offset);
		break;
	case PM8XXX_ID_FLASH_LED_0:
		addr = SSBI_REG_ADDR_FLASH_DRV0;
		break;
	case PM8XXX_ID_FLASH_LED_1:
		addr = SSBI_REG_ADDR_FLASH_DRV1;
		break;
	}

	rc = pm8xxx_readb(led->dev->parent, addr, val);
	if (rc)
		dev_err(led->cdev.dev, "can't get led(%d) level rc=%d\n",
							led->id, rc);

	return rc;
}

static int __devinit pm8xxx_led_probe(struct platform_device *pdev)
{
	const struct led_platform_data *pdata = pdev->dev.platform_data;
	struct led_info *curr_led;
	struct pm8xxx_led_data *led, *led_dat;
	int rc, i;

	if (pdata == NULL) {
		dev_err(&pdev->dev, "platform data not supplied\n");
		return -EINVAL;
	}

	led = kcalloc(pdata->num_leds, sizeof(*led), GFP_KERNEL);
	if (led == NULL) {
		dev_err(&pdev->dev, "failed to alloc memory\n");
		return -ENOMEM;
	}

	for (i = 0; i < pdata->num_leds; i++) {
		curr_led	= &pdata->leds[i];
		led_dat		= &led[i];
		/* the flags variable is used for led-id */
		led_dat->id     = curr_led->flags;

		if (!((led_dat->id >= PM8XXX_ID_LED_KB_LIGHT) &&
				(led_dat->id <= PM8XXX_ID_FLASH_LED_1))) {
			dev_err(&pdev->dev, "invalid LED ID (%d) specified\n",
						 led_dat->id);
			rc = -EINVAL;
			goto fail_id_check;
		}

		led_dat->cdev.name		= curr_led->name;
		led_dat->cdev.default_trigger   = curr_led->default_trigger;
		led_dat->cdev.brightness_set    = pm8xxx_led_set;
		led_dat->cdev.brightness_get    = pm8xxx_led_get;
		led_dat->cdev.brightness	= LED_OFF;
		led_dat->cdev.flags		= LED_CORE_SUSPENDRESUME;

		led_dat->cdev.max_brightness = get_max_brightness(led_dat->id);
		led_dat->dev = &pdev->dev;

		rc =  get_init_value(led_dat, &led_dat->reg);
		if (rc < 0)
			goto fail_id_check;

		mutex_init(&led_dat->lock);
		INIT_WORK(&led_dat->work, pm8xxx_led_work);

		rc = led_classdev_register(&pdev->dev, &led_dat->cdev);
		if (rc) {
			dev_err(&pdev->dev, "unable to register led %d,rc=%d\n",
						 led_dat->id, rc);
			goto fail_id_check;
		}
	}

	platform_set_drvdata(pdev, led);

	return 0;

fail_id_check:
	if (i > 0) {
		for (i = i - 1; i >= 0; i--) {
			mutex_destroy(&led[i].lock);
			led_classdev_unregister(&led[i].cdev);
		}
	}
	kfree(led);
	return rc;
}

static int __devexit pm8xxx_led_remove(struct platform_device *pdev)
{
	int i;
	const struct led_platform_data *pdata =
				pdev->dev.platform_data;
	struct pm8xxx_led_data *led = platform_get_drvdata(pdev);

	for (i = 0; i < pdata->num_leds; i++) {
		cancel_work_sync(&led[i].work);
		mutex_destroy(&led[i].lock);
		led_classdev_unregister(&led[i].cdev);
	}

	kfree(led);

	return 0;
}

static struct platform_driver pm8xxx_led_driver = {
	.probe		= pm8xxx_led_probe,
	.remove		= __devexit_p(pm8xxx_led_remove),
	.driver		= {
		.name	= PM8XXX_LEDS_DEV_NAME,
		.owner	= THIS_MODULE,
	},
};

static int __init pm8xxx_led_init(void)
{
	return platform_driver_register(&pm8xxx_led_driver);
}
module_init(pm8xxx_led_init);

static void __exit pm8xxx_led_exit(void)
{
	platform_driver_unregister(&pm8xxx_led_driver);
}
module_exit(pm8xxx_led_exit);

MODULE_DESCRIPTION("PM8XXX LEDs driver");
MODULE_LICENSE("GPL v2");
MODULE_VERSION("1.0");
MODULE_ALIAS("platform:pm8xxx-led");