[mirror_ubuntu-zesty-kernel.git] / drivers / platform / x86 / intel_mid_powerbtn.c

/*
 * Power button driver for Medfield.
 *
 * Copyright (C) 2010 Intel Corp
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/mfd/intel_msic.h>
#include <linux/pm_wakeirq.h>

#define DRIVER_NAME "msic_power_btn"

#define MSIC_PB_LEVEL	(1 << 3) /* 1 - release, 0 - press */

/*
 * MSIC document ti_datasheet defines the 1st bit reg 0x21 is used to mask
 * power button interrupt
 */
#define MSIC_PWRBTNM    (1 << 0)

static irqreturn_t mfld_pb_isr(int irq, void *dev_id)
{
	struct input_dev *input = dev_id;
	int ret;
	u8 pbstat;

	ret = intel_msic_reg_read(INTEL_MSIC_PBSTATUS, &pbstat);
	dev_dbg(input->dev.parent, "PB_INT status= %d\n", pbstat);

	if (ret < 0) {
		dev_err(input->dev.parent, "Read error %d while reading"
			       " MSIC_PB_STATUS\n", ret);
	} else {
		input_event(input, EV_KEY, KEY_POWER,
			       !(pbstat & MSIC_PB_LEVEL));
		input_sync(input);
	}

	return IRQ_HANDLED;
}

static int mfld_pb_probe(struct platform_device *pdev)
{
	struct input_dev *input;
	int irq = platform_get_irq(pdev, 0);
	int error;

	if (irq < 0)
		return -EINVAL;

	input = input_allocate_device();
	if (!input)
		return -ENOMEM;

	input->name = pdev->name;
	input->phys = "power-button/input0";
	input->id.bustype = BUS_HOST;
	input->dev.parent = &pdev->dev;

	input_set_capability(input, EV_KEY, KEY_POWER);

	error = request_threaded_irq(irq, NULL, mfld_pb_isr, IRQF_ONESHOT,
				     DRIVER_NAME, input);
	if (error) {
		dev_err(&pdev->dev, "Unable to request irq %d for mfld power"
				"button\n", irq);
		goto err_free_input;
	}

	device_init_wakeup(&pdev->dev, true);
	dev_pm_set_wake_irq(&pdev->dev, irq);

	error = input_register_device(input);
	if (error) {
		dev_err(&pdev->dev, "Unable to register input dev, error "
				"%d\n", error);
		goto err_free_irq;
	}

	platform_set_drvdata(pdev, input);

	/*
	 * SCU firmware might send power button interrupts to IA core before
	 * kernel boots and doesn't get EOI from IA core. The first bit of
	 * MSIC reg 0x21 is kept masked, and SCU firmware doesn't send new
	 * power interrupt to Android kernel. Unmask the bit when probing
	 * power button in kernel.
	 * There is a very narrow race between irq handler and power button
	 * initialization. The race happens rarely. So we needn't worry
	 * about it.
	 */
	error = intel_msic_reg_update(INTEL_MSIC_IRQLVL1MSK, 0, MSIC_PWRBTNM);
	if (error) {
		dev_err(&pdev->dev, "Unable to clear power button interrupt, "
				"error: %d\n", error);
		goto err_free_irq;
	}

	return 0;

err_free_irq:
	free_irq(irq, input);
err_free_input:
	input_free_device(input);
	return error;
}

static int mfld_pb_remove(struct platform_device *pdev)
{
	struct input_dev *input = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);

	dev_pm_clear_wake_irq(&pdev->dev);
	device_init_wakeup(&pdev->dev, false);
	free_irq(irq, input);
	input_unregister_device(input);

	return 0;
}

static struct platform_driver mfld_pb_driver = {
	.driver = {
		.name = DRIVER_NAME,
	},
	.probe	= mfld_pb_probe,
	.remove	= mfld_pb_remove,
};

module_platform_driver(mfld_pb_driver);

MODULE_AUTHOR("Hong Liu <hong.liu@intel.com>");
MODULE_DESCRIPTION("Intel Medfield Power Button Driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);
Commit	Line	Data
8eec8a11 HL	1	/*
	2	* Power button driver for Medfield.
	3	*
	4	* Copyright (C) 2010 Intel Corp
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; version 2 of the License.
	9	*
	10	* This program is distributed in the hope that it will be useful, but
	11	* WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along
	16	* with this program; if not, write to the Free Software Foundation, Inc.,
	17	* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
	18	*/
	19
	20	#include <linux/module.h>
	21	#include <linux/init.h>
	22	#include <linux/interrupt.h>
	23	#include <linux/slab.h>
	24	#include <linux/platform_device.h>
	25	#include <linux/input.h>
7714567c	26	#include <linux/mfd/intel_msic.h>
daea5a65	27	#include <linux/pm_wakeirq.h>
8eec8a11 HL	28
	29	#define DRIVER_NAME "msic_power_btn"
	30
b9e06694	31	#define MSIC_PB_LEVEL (1 << 3) /* 1 - release, 0 - press */
8eec8a11	32
7714567c MD	33	/*
	34	* MSIC document ti_datasheet defines the 1st bit reg 0x21 is used to mask
	35	* power button interrupt
	36	*/
	37	#define MSIC_PWRBTNM (1 << 0)
	38
8eec8a11 HL	39	static irqreturn_t mfld_pb_isr(int irq, void *dev_id)
8eec8a11 HL	40	{
b9e06694	41	struct input_dev *input = dev_id;
8eec8a11 HL	42	int ret;
	43	u8 pbstat;
	44
7714567c MD	45	ret = intel_msic_reg_read(INTEL_MSIC_PBSTATUS, &pbstat);
	46	dev_dbg(input->dev.parent, "PB_INT status= %d\n", pbstat);
	47
b9e06694 AP	48	if (ret < 0) {
	49	dev_err(input->dev.parent, "Read error %d while reading"
	50	" MSIC_PB_STATUS\n", ret);
	51	} else {
	52	input_event(input, EV_KEY, KEY_POWER,
	53	!(pbstat & MSIC_PB_LEVEL));
	54	input_sync(input);
	55	}
8eec8a11 HL	56
	57	return IRQ_HANDLED;
	58	}
	59
b859f159	60	static int mfld_pb_probe(struct platform_device *pdev)
8eec8a11	61	{
8eec8a11	62	struct input_dev *input;
b9e06694	63	int irq = platform_get_irq(pdev, 0);
8eec8a11 HL	64	int error;
8eec8a11 HL	65
8eec8a11 HL	66	if (irq < 0)
	67	return -EINVAL;
	68
8eec8a11	69	input = input_allocate_device();
b222cca6	70	if (!input)
b9e06694	71	return -ENOMEM;
8eec8a11	72
8eec8a11 HL	73	input->name = pdev->name;
	74	input->phys = "power-button/input0";
	75	input->id.bustype = BUS_HOST;
	76	input->dev.parent = &pdev->dev;
	77
	78	input_set_capability(input, EV_KEY, KEY_POWER);
	79
5a00b6c2	80	error = request_threaded_irq(irq, NULL, mfld_pb_isr, IRQF_ONESHOT,
daea5a65	81	DRIVER_NAME, input);
8eec8a11	82	if (error) {
b9e06694 AP	83	dev_err(&pdev->dev, "Unable to request irq %d for mfld power"
	84	"button\n", irq);
	85	goto err_free_input;
8eec8a11 HL	86	}
8eec8a11 HL	87
daea5a65 SH	88	device_init_wakeup(&pdev->dev, true);
	89	dev_pm_set_wake_irq(&pdev->dev, irq);
	90
8eec8a11 HL	91	error = input_register_device(input);
8eec8a11 HL	92	if (error) {
b9e06694 AP	93	dev_err(&pdev->dev, "Unable to register input dev, error "
b9e06694 AP	94	"%d\n", error);
8eec8a11 HL	95	goto err_free_irq;
	96	}
	97
b9e06694	98	platform_set_drvdata(pdev, input);
7714567c MD	99
	100	/*
	101	* SCU firmware might send power button interrupts to IA core before
	102	* kernel boots and doesn't get EOI from IA core. The first bit of
	103	* MSIC reg 0x21 is kept masked, and SCU firmware doesn't send new
	104	* power interrupt to Android kernel. Unmask the bit when probing
	105	* power button in kernel.
	106	* There is a very narrow race between irq handler and power button
	107	* initialization. The race happens rarely. So we needn't worry
	108	* about it.
	109	*/
	110	error = intel_msic_reg_update(INTEL_MSIC_IRQLVL1MSK, 0, MSIC_PWRBTNM);
	111	if (error) {
	112	dev_err(&pdev->dev, "Unable to clear power button interrupt, "
	113	"error: %d\n", error);
	114	goto err_free_irq;
	115	}
	116
8eec8a11 HL	117	return 0;
	118
	119	err_free_irq:
b9e06694 AP	120	free_irq(irq, input);
b9e06694 AP	121	err_free_input:
8eec8a11	122	input_free_device(input);
8eec8a11 HL	123	return error;
	124	}
	125
b859f159	126	static int mfld_pb_remove(struct platform_device *pdev)
8eec8a11	127	{
b9e06694 AP	128	struct input_dev *input = platform_get_drvdata(pdev);
b9e06694 AP	129	int irq = platform_get_irq(pdev, 0);
8eec8a11	130
daea5a65 SH	131	dev_pm_clear_wake_irq(&pdev->dev);
daea5a65 SH	132	device_init_wakeup(&pdev->dev, false);
b9e06694 AP	133	free_irq(irq, input);
b9e06694 AP	134	input_unregister_device(input);
b9e06694	135
8eec8a11 HL	136	return 0;
	137	}
	138
	139	static struct platform_driver mfld_pb_driver = {
	140	.driver = {
	141	.name = DRIVER_NAME,
8eec8a11 HL	142	},
8eec8a11 HL	143	.probe = mfld_pb_probe,
b859f159	144	.remove = mfld_pb_remove,
8eec8a11 HL	145	};
8eec8a11 HL	146
73d99a22	147	module_platform_driver(mfld_pb_driver);
8eec8a11 HL	148
	149	MODULE_AUTHOR("Hong Liu <hong.liu@intel.com>");
	150	MODULE_DESCRIPTION("Intel Medfield Power Button Driver");
	151	MODULE_LICENSE("GPL v2");
	152	MODULE_ALIAS("platform:" DRIVER_NAME);