android_kernel_samsung_msm8976/drivers/misc/apq8084_dock.c

/* Copyright (c) 2013, The Linux Foundation. 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/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/pm_wakeup.h>
#include <linux/workqueue.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>

struct apq8084_dock {
	struct device		*dev;
	struct work_struct	dock_work;
	int			dock_detect;
	int			dock_hub_reset;
	int			dock_eth_reset;
	int			dock_enable;
};

static void dock_detected_work(struct work_struct *w)
{
	struct apq8084_dock *dock = container_of(w, struct apq8084_dock,
						 dock_work);
	int docked;

	docked = gpio_get_value(dock->dock_detect);
	gpio_direction_output(dock->dock_enable, 0);

	if (docked) {
		/* assert RESETs before turning on power */
		gpio_direction_output(dock->dock_hub_reset, 1);
		gpio_direction_output(dock->dock_eth_reset, 1);
		gpio_direction_output(dock->dock_enable, 1);

		msleep(20); /* short delay before de-asserting RESETs */
		gpio_direction_output(dock->dock_hub_reset, 0);
		gpio_direction_output(dock->dock_eth_reset, 0);
	}

	/* Allow system suspend */
	pm_relax(dock->dev);
}

static irqreturn_t dock_detected(int irq, void *data)
{
	struct apq8084_dock *dock = data;

	/* Ensure suspend can't happen until after work function commpletes */
	pm_stay_awake(dock->dev);
	schedule_work(&dock->dock_work);
	return IRQ_HANDLED;
}

static int apq8084_dock_probe(struct platform_device *pdev)
{
	struct device_node *node = pdev->dev.of_node;
	struct apq8084_dock *dock;
	int ret;

	dock = devm_kzalloc(&pdev->dev, sizeof(*dock), GFP_KERNEL);
	if (!dock)
		return -ENOMEM;

	dock->dev = &pdev->dev;
	platform_set_drvdata(pdev, dock);
	INIT_WORK(&dock->dock_work, dock_detected_work);

	dock->dock_detect = of_get_named_gpio(node, "qcom,dock-detect-gpio", 0);
	if (dock->dock_detect < 0) {
		dev_err(dock->dev, "unable to get dock-detect-gpio\n");
		return dock->dock_detect;
	}

	ret = devm_request_irq(&pdev->dev, gpio_to_irq(dock->dock_detect),
				dock_detected, IRQF_TRIGGER_RISING |
				IRQF_TRIGGER_FALLING | IRQF_SHARED,
				"dock_detect_irq", dock);
	if (ret)
		return ret;

	dock->dock_hub_reset = of_get_named_gpio(node,
						 "qcom,dock-hub-reset-gpio", 0);
	if (dock->dock_hub_reset < 0) {
		dev_err(dock->dev, "unable to get dock-hub-reset-gpio\n");
		return dock->dock_hub_reset;
	}

	ret = devm_gpio_request(dock->dev, dock->dock_hub_reset,
				"dock_hub_reset");
	if (ret)
		return ret;

	dock->dock_eth_reset = of_get_named_gpio(node,
						 "qcom,dock-eth-reset-gpio", 0);
	if (dock->dock_eth_reset < 0) {
		dev_err(dock->dev, "unable to get dock-eth-reset-gpio\n");
		return dock->dock_eth_reset;
	}

	ret = devm_gpio_request(dock->dev, dock->dock_eth_reset,
				"dock_eth_reset");
	if (ret)
		return ret;

	dock->dock_enable = of_get_named_gpio(node, "qcom,dock-enable-gpio", 0);
	if (dock->dock_enable < 0) {
		dev_err(dock->dev, "unable to get dock-enable-gpio\n");
		return dock->dock_enable;
	}

	ret = devm_gpio_request(dock->dev, dock->dock_enable, "dock_enable");
	if (ret)
		return ret;

	schedule_work(&dock->dock_work);
	device_init_wakeup(dock->dev, true);
	enable_irq_wake(gpio_to_irq(dock->dock_detect));

	return 0;
}

static int apq8084_dock_remove(struct platform_device *pdev)
{
	struct apq8084_dock *dock = platform_get_drvdata(pdev);

	disable_irq_wake(gpio_to_irq(dock->dock_detect));
	cancel_work_sync(&dock->dock_work);

	return 0;
}

static struct of_device_id of_match_table[] = {
	{       .compatible = "qcom,apq8084-dock",
	}
};

static struct platform_driver apq8084_dock_driver = {
	.driver         = {
		.name   = "apq8084-dock-driver",
		.of_match_table = of_match_table,
	},
	.probe          = apq8084_dock_probe,
	.remove		= apq8084_dock_remove,
};

module_platform_driver(apq8084_dock_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("QTI APQ8084 Docking Station driver");