linux-imx

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

/* Lantiq cpu temperature sensor driver

 *

 * Copyright (C) 2017 Florian Eckert <fe@dev.tdt.de>

 */

​

#include <linux/bitops.h>

#include <linux/delay.h>

#include <linux/hwmon.h>

#include <linux/hwmon-sysfs.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/of_device.h>

​

#include <lantiq_soc.h>

​

/* gphy1 configuration register contains cpu temperature */

#define CGU_GPHY1_CR   0x0040

#define CGU_TEMP_PD    BIT(19)

​

static void ltq_cputemp_enable(void)

{

    ltq_cgu_w32(ltq_cgu_r32(CGU_GPHY1_CR) | CGU_TEMP_PD, CGU_GPHY1_CR);

}

​

static void ltq_cputemp_disable(void *data)

{

    ltq_cgu_w32(ltq_cgu_r32(CGU_GPHY1_CR) & ~CGU_TEMP_PD, CGU_GPHY1_CR);

}

​

static int ltq_read(struct device *dev, enum hwmon_sensor_types type,

            u32 attr, int channel, long *temp)

{

    int value;

​

    switch (attr) {

    case hwmon_temp_input:

        /* get the temperature including one decimal place */

        value = (ltq_cgu_r32(CGU_GPHY1_CR) >> 9) & 0x01FF;

        value = value * 5;

        /* range -38 to +154 °C, register value zero is -38.0 °C */

        value -= 380;

        /* scale temp to millidegree */

        value = value * 100;

        break;

    default:

        return -EOPNOTSUPP;

    }

​

    *temp = value;

    return 0;

}

​

static umode_t ltq_is_visible(const void *_data, enum hwmon_sensor_types type,

                  u32 attr, int channel)

{

    if (type != hwmon_temp)

        return 0;

​

    switch (attr) {

    case hwmon_temp_input:

        return 0444;

    default: