135 lines
2.9 KiB
C
135 lines
2.9 KiB
C
// 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/mod_devicetable.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_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:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static const struct hwmon_channel_info * const ltq_info[] = {
|
|
HWMON_CHANNEL_INFO(chip,
|
|
HWMON_C_REGISTER_TZ),
|
|
HWMON_CHANNEL_INFO(temp,
|
|
HWMON_T_INPUT),
|
|
NULL
|
|
};
|
|
|
|
static const struct hwmon_ops ltq_hwmon_ops = {
|
|
.is_visible = ltq_is_visible,
|
|
.read = ltq_read,
|
|
};
|
|
|
|
static const struct hwmon_chip_info ltq_chip_info = {
|
|
.ops = <q_hwmon_ops,
|
|
.info = ltq_info,
|
|
};
|
|
|
|
static int ltq_cputemp_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *hwmon_dev;
|
|
int err = 0;
|
|
|
|
/* available on vr9 v1.2 SoCs only */
|
|
if (ltq_soc_type() != SOC_TYPE_VR9_2)
|
|
return -ENODEV;
|
|
|
|
err = devm_add_action(&pdev->dev, ltq_cputemp_disable, NULL);
|
|
if (err)
|
|
return err;
|
|
|
|
ltq_cputemp_enable();
|
|
|
|
hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
|
|
"ltq_cputemp",
|
|
NULL,
|
|
<q_chip_info,
|
|
NULL);
|
|
|
|
if (IS_ERR(hwmon_dev)) {
|
|
dev_err(&pdev->dev, "Failed to register as hwmon device");
|
|
return PTR_ERR(hwmon_dev);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct of_device_id ltq_cputemp_match[] = {
|
|
{ .compatible = "lantiq,cputemp" },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ltq_cputemp_match);
|
|
|
|
static struct platform_driver ltq_cputemp_driver = {
|
|
.probe = ltq_cputemp_probe,
|
|
.driver = {
|
|
.name = "ltq-cputemp",
|
|
.of_match_table = ltq_cputemp_match,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(ltq_cputemp_driver);
|
|
|
|
MODULE_AUTHOR("Florian Eckert <fe@dev.tdt.de>");
|
|
MODULE_DESCRIPTION("Lantiq cpu temperature sensor driver");
|
|
MODULE_LICENSE("GPL");
|