linux-imx

// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>

 * JZ4740 SoC HWMON driver

 */

​

#include <linux/err.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/io.h>

​

#include <linux/completion.h>

#include <linux/mfd/core.h>

​

#include <linux/hwmon.h>

​

struct jz4740_hwmon {

    void __iomem *base;

    int irq;

    const struct mfd_cell *cell;

    struct platform_device *pdev;

    struct completion read_completion;

    struct mutex lock;

};

​

static irqreturn_t jz4740_hwmon_irq(int irq, void *data)

{

    struct jz4740_hwmon *hwmon = data;

​

    complete(&hwmon->read_completion);

    return IRQ_HANDLED;

}

​

static ssize_t in0_input_show(struct device *dev,

                  struct device_attribute *dev_attr, char *buf)

{

    struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);

    struct platform_device *pdev = hwmon->pdev;

    struct completion *completion = &hwmon->read_completion;

    long t;

    unsigned long val;

    int ret;

​

    mutex_lock(&hwmon->lock);

​

    reinit_completion(completion);

​

    enable_irq(hwmon->irq);

    hwmon->cell->enable(pdev);

​

    t = wait_for_completion_interruptible_timeout(completion, HZ);

​

    if (t > 0) {

        val = readw(hwmon->base) & 0xfff;

        val = (val * 3300) >> 12;

        ret = sprintf(buf, "%lu\n", val);

    } else {

        ret = t ? t : -ETIMEDOUT;

    }