linux/drivers/hwmon/oxp-sensors.c
Joaquín Ignacio Aramendía 0cd3ba682a hwmon: (oxp-sensors) Fix pwm reading
PWM reading is only 1 register long.

Signed-off-by: Joaquín Ignacio Aramendía <samsagax@gmail.com>
Link: https://lore.kernel.org/r/20221128185206.212022-1-samsagax@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2022-12-04 16:45:03 -08:00

285 lines
6.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Platform driver for OXP Handhelds that expose fan reading and control
* via hwmon sysfs.
*
* Old boards have the same DMI strings and they are told appart by the
* boot cpu vendor (Intel/AMD). Currently only AMD boards are supported
* but the code is made to be simple to add other handheld boards in the
* future.
* Fan control is provided via pwm interface in the range [0-255].
* Old AMD boards use [0-100] as range in the EC, the written value is
* scaled to accommodate for that. Newer boards like the mini PRO and
* AOK ZOE are not scaled but have the same EC layout.
*
* Copyright (C) 2022 Joaquín I. Aramendía <samsagax@gmail.com>
*/
#include <linux/acpi.h>
#include <linux/dev_printk.h>
#include <linux/dmi.h>
#include <linux/hwmon.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/processor.h>
/* Handle ACPI lock mechanism */
static u32 oxp_mutex;
#define ACPI_LOCK_DELAY_MS 500
static bool lock_global_acpi_lock(void)
{
return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS, &oxp_mutex));
}
static bool unlock_global_acpi_lock(void)
{
return ACPI_SUCCESS(acpi_release_global_lock(oxp_mutex));
}
enum oxp_board {
aok_zoe_a1 = 1,
oxp_mini_amd,
oxp_mini_amd_pro,
};
static enum oxp_board board;
#define OXP_SENSOR_FAN_REG 0x76 /* Fan reading is 2 registers long */
#define OXP_SENSOR_PWM_ENABLE_REG 0x4A /* PWM enable is 1 register long */
#define OXP_SENSOR_PWM_REG 0x4B /* PWM reading is 1 register long */
static const struct dmi_system_id dmi_table[] = {
{
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "AOKZOE"),
DMI_EXACT_MATCH(DMI_BOARD_NAME, "AOKZOE A1 AR07"),
},
.driver_data = (void *) &(enum oxp_board) {aok_zoe_a1},
},
{
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONE XPLAYER"),
},
.driver_data = (void *) &(enum oxp_board) {oxp_mini_amd},
},
{
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONEXPLAYER Mini Pro"),
},
.driver_data = (void *) &(enum oxp_board) {oxp_mini_amd_pro},
},
{},
};
/* Helper functions to handle EC read/write */
static int read_from_ec(u8 reg, int size, long *val)
{
int i;
int ret;
u8 buffer;
if (!lock_global_acpi_lock())
return -EBUSY;
*val = 0;
for (i = 0; i < size; i++) {
ret = ec_read(reg + i, &buffer);
if (ret)
return ret;
*val <<= i * 8;
*val += buffer;
}
if (!unlock_global_acpi_lock())
return -EBUSY;
return 0;
}
static int write_to_ec(const struct device *dev, u8 reg, u8 value)
{
int ret;
if (!lock_global_acpi_lock())
return -EBUSY;
ret = ec_write(reg, value);
if (!unlock_global_acpi_lock())
return -EBUSY;
return ret;
}
static int oxp_pwm_enable(const struct device *dev)
{
return write_to_ec(dev, OXP_SENSOR_PWM_ENABLE_REG, 0x01);
}
static int oxp_pwm_disable(const struct device *dev)
{
return write_to_ec(dev, OXP_SENSOR_PWM_ENABLE_REG, 0x00);
}
/* Callbacks for hwmon interface */
static umode_t oxp_ec_hwmon_is_visible(const void *drvdata,
enum hwmon_sensor_types type, u32 attr, int channel)
{
switch (type) {
case hwmon_fan:
return 0444;
case hwmon_pwm:
return 0644;
default:
return 0;
}
}
static int oxp_platform_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
int ret;
switch (type) {
case hwmon_fan:
switch (attr) {
case hwmon_fan_input:
return read_from_ec(OXP_SENSOR_FAN_REG, 2, val);
default:
break;
}
break;
case hwmon_pwm:
switch (attr) {
case hwmon_pwm_input:
ret = read_from_ec(OXP_SENSOR_PWM_REG, 1, val);
if (ret)
return ret;
if (board == oxp_mini_amd)
*val = (*val * 255) / 100;
return 0;
case hwmon_pwm_enable:
return read_from_ec(OXP_SENSOR_PWM_ENABLE_REG, 1, val);
default:
break;
}
break;
default:
break;
}
return -EOPNOTSUPP;
}
static int oxp_platform_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
switch (type) {
case hwmon_pwm:
switch (attr) {
case hwmon_pwm_enable:
if (val == 1)
return oxp_pwm_enable(dev);
else if (val == 0)
return oxp_pwm_disable(dev);
return -EINVAL;
case hwmon_pwm_input:
if (val < 0 || val > 255)
return -EINVAL;
if (board == oxp_mini_amd)
val = (val * 100) / 255;
return write_to_ec(dev, OXP_SENSOR_PWM_REG, val);
default:
break;
}
break;
default:
break;
}
return -EOPNOTSUPP;
}
/* Known sensors in the OXP EC controllers */
static const struct hwmon_channel_info *oxp_platform_sensors[] = {
HWMON_CHANNEL_INFO(fan,
HWMON_F_INPUT),
HWMON_CHANNEL_INFO(pwm,
HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
NULL,
};
static const struct hwmon_ops oxp_ec_hwmon_ops = {
.is_visible = oxp_ec_hwmon_is_visible,
.read = oxp_platform_read,
.write = oxp_platform_write,
};
static const struct hwmon_chip_info oxp_ec_chip_info = {
.ops = &oxp_ec_hwmon_ops,
.info = oxp_platform_sensors,
};
/* Initialization logic */
static int oxp_platform_probe(struct platform_device *pdev)
{
const struct dmi_system_id *dmi_entry;
struct device *dev = &pdev->dev;
struct device *hwdev;
/*
* Have to check for AMD processor here because DMI strings are the
* same between Intel and AMD boards, the only way to tell them appart
* is the CPU.
* Intel boards seem to have different EC registers and values to
* read/write.
*/
dmi_entry = dmi_first_match(dmi_table);
if (!dmi_entry || boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
return -ENODEV;
board = *((enum oxp_board *) dmi_entry->driver_data);
hwdev = devm_hwmon_device_register_with_info(dev, "oxpec", NULL,
&oxp_ec_chip_info, NULL);
return PTR_ERR_OR_ZERO(hwdev);
}
static struct platform_driver oxp_platform_driver = {
.driver = {
.name = "oxp-platform",
},
.probe = oxp_platform_probe,
};
static struct platform_device *oxp_platform_device;
static int __init oxp_platform_init(void)
{
oxp_platform_device =
platform_create_bundle(&oxp_platform_driver,
oxp_platform_probe, NULL, 0, NULL, 0);
return PTR_ERR_OR_ZERO(oxp_platform_device);
}
static void __exit oxp_platform_exit(void)
{
platform_device_unregister(oxp_platform_device);
platform_driver_unregister(&oxp_platform_driver);
}
MODULE_DEVICE_TABLE(dmi, dmi_table);
module_init(oxp_platform_init);
module_exit(oxp_platform_exit);
MODULE_AUTHOR("Joaquín Ignacio Aramendía <samsagax@gmail.com>");
MODULE_DESCRIPTION("Platform driver that handles EC sensors of OneXPlayer devices");
MODULE_LICENSE("GPL");