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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wm831x-on.c (3922B)

      1/*
      2 * wm831x-on.c - WM831X ON pin driver
      3 *
      4 * Copyright (C) 2009 Wolfson Microelectronics plc
      5 *
      6 * This file is subject to the terms and conditions of the GNU General
      7 * Public License. See the file "COPYING" in the main directory of this
      8 * archive for more details.
      9 *
     10 * This program is distributed in the hope that it will be useful,
     11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
     12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13 * GNU General Public License for more details.
     14 *
     15 * You should have received a copy of the GNU General Public License
     16 * along with this program; if not, write to the Free Software
     17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
     18 */
     19
     20#include <linux/module.h>
     21#include <linux/slab.h>
     22#include <linux/kernel.h>
     23#include <linux/errno.h>
     24#include <linux/input.h>
     25#include <linux/interrupt.h>
     26#include <linux/platform_device.h>
     27#include <linux/workqueue.h>
     28#include <linux/mfd/wm831x/core.h>
     29
     30struct wm831x_on {
     31	struct input_dev *dev;
     32	struct delayed_work work;
     33	struct wm831x *wm831x;
     34};
     35
     36/*
     37 * The chip gives us an interrupt when the ON pin is asserted but we
     38 * then need to poll to see when the pin is deasserted.
     39 */
     40static void wm831x_poll_on(struct work_struct *work)
     41{
     42	struct wm831x_on *wm831x_on = container_of(work, struct wm831x_on,
     43						   work.work);
     44	struct wm831x *wm831x = wm831x_on->wm831x;
     45	int poll, ret;
     46
     47	ret = wm831x_reg_read(wm831x, WM831X_ON_PIN_CONTROL);
     48	if (ret >= 0) {
     49		poll = !(ret & WM831X_ON_PIN_STS);
     50
     51		input_report_key(wm831x_on->dev, KEY_POWER, poll);
     52		input_sync(wm831x_on->dev);
     53	} else {
     54		dev_err(wm831x->dev, "Failed to read ON status: %d\n", ret);
     55		poll = 1;
     56	}
     57
     58	if (poll)
     59		schedule_delayed_work(&wm831x_on->work, 100);
     60}
     61
     62static irqreturn_t wm831x_on_irq(int irq, void *data)
     63{
     64	struct wm831x_on *wm831x_on = data;
     65
     66	schedule_delayed_work(&wm831x_on->work, 0);
     67
     68	return IRQ_HANDLED;
     69}
     70
     71static int wm831x_on_probe(struct platform_device *pdev)
     72{
     73	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
     74	struct wm831x_on *wm831x_on;
     75	int irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
     76	int ret;
     77
     78	wm831x_on = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_on),
     79				 GFP_KERNEL);
     80	if (!wm831x_on) {
     81		dev_err(&pdev->dev, "Can't allocate data\n");
     82		return -ENOMEM;
     83	}
     84
     85	wm831x_on->wm831x = wm831x;
     86	INIT_DELAYED_WORK(&wm831x_on->work, wm831x_poll_on);
     87
     88	wm831x_on->dev = devm_input_allocate_device(&pdev->dev);
     89	if (!wm831x_on->dev) {
     90		dev_err(&pdev->dev, "Can't allocate input dev\n");
     91		ret = -ENOMEM;
     92		goto err;
     93	}
     94
     95	wm831x_on->dev->evbit[0] = BIT_MASK(EV_KEY);
     96	wm831x_on->dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
     97	wm831x_on->dev->name = "wm831x_on";
     98	wm831x_on->dev->phys = "wm831x_on/input0";
     99	wm831x_on->dev->dev.parent = &pdev->dev;
    100
    101	ret = request_threaded_irq(irq, NULL, wm831x_on_irq,
    102				   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
    103				   "wm831x_on",
    104				   wm831x_on);
    105	if (ret < 0) {
    106		dev_err(&pdev->dev, "Unable to request IRQ: %d\n", ret);
    107		goto err_input_dev;
    108	}
    109	ret = input_register_device(wm831x_on->dev);
    110	if (ret) {
    111		dev_dbg(&pdev->dev, "Can't register input device: %d\n", ret);
    112		goto err_irq;
    113	}
    114
    115	platform_set_drvdata(pdev, wm831x_on);
    116
    117	return 0;
    118
    119err_irq:
    120	free_irq(irq, wm831x_on);
    121err_input_dev:
    122err:
    123	return ret;
    124}
    125
    126static int wm831x_on_remove(struct platform_device *pdev)
    127{
    128	struct wm831x_on *wm831x_on = platform_get_drvdata(pdev);
    129	int irq = platform_get_irq(pdev, 0);
    130
    131	free_irq(irq, wm831x_on);
    132	cancel_delayed_work_sync(&wm831x_on->work);
    133
    134	return 0;
    135}
    136
    137static struct platform_driver wm831x_on_driver = {
    138	.probe		= wm831x_on_probe,
    139	.remove		= wm831x_on_remove,
    140	.driver		= {
    141		.name	= "wm831x-on",
    142	},
    143};
    144module_platform_driver(wm831x_on_driver);
    145
    146MODULE_ALIAS("platform:wm831x-on");
    147MODULE_DESCRIPTION("WM831x ON pin");
    148MODULE_LICENSE("GPL");
    149MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
    150