cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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max8925_onkey.c (4704B)


      1/*
      2 * MAX8925 ONKEY driver
      3 *
      4 * Copyright (C) 2009 Marvell International Ltd.
      5 *      Haojian Zhuang <haojian.zhuang@marvell.com>
      6 *
      7 * This file is subject to the terms and conditions of the GNU General
      8 * Public License. See the file "COPYING" in the main directory of this
      9 * archive for more details.
     10 *
     11 * This program is distributed in the hope that it will be useful,
     12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     14 * GNU General Public License for more details.
     15 *
     16 * You should have received a copy of the GNU General Public License
     17 * along with this program; if not, write to the Free Software
     18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
     19 */
     20
     21#include <linux/kernel.h>
     22#include <linux/module.h>
     23#include <linux/platform_device.h>
     24#include <linux/i2c.h>
     25#include <linux/input.h>
     26#include <linux/interrupt.h>
     27#include <linux/mfd/max8925.h>
     28#include <linux/slab.h>
     29#include <linux/device.h>
     30
     31#define SW_INPUT		(1 << 7)	/* 0/1 -- up/down */
     32#define HARDRESET_EN		(1 << 7)
     33#define PWREN_EN		(1 << 7)
     34
     35struct max8925_onkey_info {
     36	struct input_dev	*idev;
     37	struct i2c_client	*i2c;
     38	struct device		*dev;
     39	unsigned int		irq[2];
     40};
     41
     42/*
     43 * MAX8925 gives us an interrupt when ONKEY is pressed or released.
     44 * max8925_set_bits() operates I2C bus and may sleep. So implement
     45 * it in thread IRQ handler.
     46 */
     47static irqreturn_t max8925_onkey_handler(int irq, void *data)
     48{
     49	struct max8925_onkey_info *info = data;
     50	int state;
     51
     52	state = max8925_reg_read(info->i2c, MAX8925_ON_OFF_STATUS);
     53
     54	input_report_key(info->idev, KEY_POWER, state & SW_INPUT);
     55	input_sync(info->idev);
     56
     57	dev_dbg(info->dev, "onkey state:%d\n", state);
     58
     59	/* Enable hardreset to halt if system isn't shutdown on time */
     60	max8925_set_bits(info->i2c, MAX8925_SYSENSEL,
     61			 HARDRESET_EN, HARDRESET_EN);
     62
     63	return IRQ_HANDLED;
     64}
     65
     66static int max8925_onkey_probe(struct platform_device *pdev)
     67{
     68	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
     69	struct max8925_onkey_info *info;
     70	struct input_dev *input;
     71	int irq[2], error;
     72
     73	irq[0] = platform_get_irq(pdev, 0);
     74	if (irq[0] < 0)
     75		return -EINVAL;
     76
     77	irq[1] = platform_get_irq(pdev, 1);
     78	if (irq[1] < 0)
     79		return -EINVAL;
     80
     81	info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_onkey_info),
     82			    GFP_KERNEL);
     83	if (!info)
     84		return -ENOMEM;
     85
     86	input = devm_input_allocate_device(&pdev->dev);
     87	if (!input)
     88		return -ENOMEM;
     89
     90	info->idev = input;
     91	info->i2c = chip->i2c;
     92	info->dev = &pdev->dev;
     93	info->irq[0] = irq[0];
     94	info->irq[1] = irq[1];
     95
     96	input->name = "max8925_on";
     97	input->phys = "max8925_on/input0";
     98	input->id.bustype = BUS_I2C;
     99	input->dev.parent = &pdev->dev;
    100	input_set_capability(input, EV_KEY, KEY_POWER);
    101
    102	error = devm_request_threaded_irq(&pdev->dev, irq[0], NULL,
    103					  max8925_onkey_handler, IRQF_ONESHOT,
    104					  "onkey-down", info);
    105	if (error < 0) {
    106		dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
    107			irq[0], error);
    108		return error;
    109	}
    110
    111	error = devm_request_threaded_irq(&pdev->dev, irq[1], NULL,
    112					  max8925_onkey_handler, IRQF_ONESHOT,
    113					  "onkey-up", info);
    114	if (error < 0) {
    115		dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
    116			irq[1], error);
    117		return error;
    118	}
    119
    120	error = input_register_device(info->idev);
    121	if (error) {
    122		dev_err(chip->dev, "Can't register input device: %d\n", error);
    123		return error;
    124	}
    125
    126	platform_set_drvdata(pdev, info);
    127	device_init_wakeup(&pdev->dev, 1);
    128
    129	return 0;
    130}
    131
    132static int __maybe_unused max8925_onkey_suspend(struct device *dev)
    133{
    134	struct platform_device *pdev = to_platform_device(dev);
    135	struct max8925_onkey_info *info = platform_get_drvdata(pdev);
    136	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
    137
    138	if (device_may_wakeup(dev)) {
    139		chip->wakeup_flag |= 1 << info->irq[0];
    140		chip->wakeup_flag |= 1 << info->irq[1];
    141	}
    142
    143	return 0;
    144}
    145
    146static int __maybe_unused max8925_onkey_resume(struct device *dev)
    147{
    148	struct platform_device *pdev = to_platform_device(dev);
    149	struct max8925_onkey_info *info = platform_get_drvdata(pdev);
    150	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
    151
    152	if (device_may_wakeup(dev)) {
    153		chip->wakeup_flag &= ~(1 << info->irq[0]);
    154		chip->wakeup_flag &= ~(1 << info->irq[1]);
    155	}
    156
    157	return 0;
    158}
    159
    160static SIMPLE_DEV_PM_OPS(max8925_onkey_pm_ops, max8925_onkey_suspend, max8925_onkey_resume);
    161
    162static struct platform_driver max8925_onkey_driver = {
    163	.driver		= {
    164		.name	= "max8925-onkey",
    165		.pm	= &max8925_onkey_pm_ops,
    166	},
    167	.probe		= max8925_onkey_probe,
    168};
    169module_platform_driver(max8925_onkey_driver);
    170
    171MODULE_DESCRIPTION("Maxim MAX8925 ONKEY driver");
    172MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
    173MODULE_LICENSE("GPL");