hwmon: (bt1-pvt) Test sensor power supply on probe

#include <linux/bitops.h>

#include <linux/clk.h>

#include <linux/completion.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/hwmon-sysfs.h>

#include <linux/hwmon.h>

	return 0;

}

static int pvt_check_pwr(struct pvt_hwmon *pvt)

{

	unsigned long tout;

	int ret = 0;

	u32 data;

	/*

	 * Test out the sensor conversion functionality. If it is not done on

	 * time then the domain must have been unpowered and we won't be able

	 * to use the device later in this driver.

	 * Note If the power source is lost during the normal driver work the

	 * data read procedure will either return -ETIMEDOUT (for the

	 * alarm-less driver configuration) or just stop the repeated

	 * conversion. In the later case alas we won't be able to detect the

	 * problem.

	 */

	pvt_update(pvt->regs + PVT_INTR_MASK, PVT_INTR_ALL, PVT_INTR_ALL);

	pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, PVT_CTRL_EN);

	pvt_set_tout(pvt, 0);

	readl(pvt->regs + PVT_DATA);

	tout = PVT_TOUT_MIN / NSEC_PER_USEC;

	usleep_range(tout, 2 * tout);

	data = readl(pvt->regs + PVT_DATA);

	if (!(data & PVT_DATA_VALID)) {

		ret = -ENODEV;

		dev_err(pvt->dev, "Sensor is powered down\n");

	}

	pvt_update(pvt->regs + PVT_CTRL, PVT_CTRL_EN, 0);

	return ret;

}

static void pvt_init_iface(struct pvt_hwmon *pvt)

{

	u32 trim, temp;

	if (ret)

		return ret;

	ret = pvt_check_pwr(pvt);

	if (ret)

		return ret;

	pvt_init_iface(pvt);

	ret = pvt_request_irq(pvt);