Re: [PATCH v3] Add OneXPlayer mini AMD sensors driver

[Guenter Roeck <linux@roeck-us.net>]

On Mon, Oct 31, 2022 at 11:53:08AM -0300, Joaquín Ignacio Aramendía wrote:
> Sensors driver for OXP Handhelds from One-Netbook that expose fan reading
> and control via hwmon sysfs.
> 
> As far as I could gather all OXP boards have the same DMI strings and
> they are told appart by the boot cpu vendor (Intel/AMD).
> Currently only AMD boards are supported.
> 
> Fan control is provided via pwm interface in the range [0-255]. AMD
> boards have [0-100] as range in the EC, the written value is scaled to
> accommodate for that.
> 
> Signed-off-by: Joaquín Ignacio Aramendía <samsagax@gmail.com>

I didn't have time to look at your patch, but _pease_ stop sending new
versions of your patches in response to previous versions.

Guenter

> ---
> Removed fan_control reference in comment.
> Bugfix MIX/MIN reporting not available
> Bugfix pwm_enable register set wrong
> ---
>  drivers/hwmon/Kconfig       |  13 +-
>  drivers/hwmon/Makefile      |   1 +
>  drivers/hwmon/oxp-sensors.c | 277 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 290 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/hwmon/oxp-sensors.c
> 
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 7ac3daaf59ce..a1cdb03b4d13 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1607,6 +1607,17 @@ config SENSORS_NZXT_SMART2
> 
>  source "drivers/hwmon/occ/Kconfig"
> 
> +config SENSORS_OXP
> +	tristate "OneXPlayer EC fan control"
> +	depends on ACPI
> +	depends on X86
> +	help
> +		If you say yes here you get support for fan readings and control over
> +		OneXPlayer handheld devices. Only OneXPlayer mini AMD handheld variant
> +		boards are supported.
> +
> +		Can also be built as a module. In that case it will be called oxp-sensors.
> +
>  config SENSORS_PCF8591
>  	tristate "Philips PCF8591 ADC/DAC"
>  	depends on I2C
> @@ -1957,7 +1968,7 @@ config SENSORS_ADS7871
> 
>  config SENSORS_AMC6821
>  	tristate "Texas Instruments AMC6821"
> -	depends on I2C
> +	depends on I2C
>  	help
>  	  If you say yes here you get support for the Texas Instruments
>  	  AMC6821 hardware monitoring chips.
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 11d076cad8a2..35824f8be455 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -167,6 +167,7 @@ obj-$(CONFIG_SENSORS_NSA320)	+= nsa320-hwmon.o
>  obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o
>  obj-$(CONFIG_SENSORS_NZXT_KRAKEN2) += nzxt-kraken2.o
>  obj-$(CONFIG_SENSORS_NZXT_SMART2) += nzxt-smart2.o
> +obj-$(CONFIG_SENSORS_OXP) += oxp-sensors.o
>  obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
>  obj-$(CONFIG_SENSORS_PC87427)	+= pc87427.o
>  obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
> diff --git a/drivers/hwmon/oxp-sensors.c b/drivers/hwmon/oxp-sensors.c
> new file mode 100644
> index 000000000000..f5895dc11094
> --- /dev/null
> +++ b/drivers/hwmon/oxp-sensors.c
> @@ -0,0 +1,277 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Platform driver for OXP Handhelds that expose fan reading and control
> + * via hwmon sysfs.
> + *
> + * All 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]. AMD
> + * boards use [0-100] as range in the EC, the written value is scaled to
> + * accommodate for that.
> + *
> + * 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>
> +
> +#define ACPI_LOCK_DELAY_MS	500
> +
> +/* Handle ACPI lock mechanism */
> +struct lock_data {
> +	u32 mutex;
> +	bool (*lock)(struct lock_data *data);
> +	bool (*unlock)(struct lock_data *data);
> +};
> +
> +static bool lock_global_acpi_lock(struct lock_data *data)
> +{
> +	return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS,
> +								 &data->mutex));
> +}
> +
> +static bool unlock_global_acpi_lock(struct lock_data *data)
> +{
> +	return ACPI_SUCCESS(acpi_release_global_lock(data->mutex));
> +}
> +
> +#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_EXACT_MATCH(DMI_BOARD_VENDOR,
> +					"ONE-NETBOOK TECHNOLOGY CO., LTD."),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_EXACT_MATCH(DMI_BOARD_VENDOR,
> +					"ONE-NETBOOK"),
> +		},
> +	},
> +	{},
> +};
> +
> +struct oxp_status {
> +	struct lock_data lock_data;
> +};
> +
> +/* Helper functions to handle EC read/write */
> +static int read_from_ec(u8 reg, int size, long *val)
> +{
> +	int i;
> +	int ret;
> +	u8 buffer;
> +
> +	*val = 0;
> +	for (i = 0; i < size; i++) {
> +		ret = ec_read(reg + i, &buffer);
> +		if (ret)
> +			return ret;
> +		(*val) <<= i * 8;
> +		*val += buffer;
> +	}
> +	return ret;
> +}
> +
> +static int write_to_ec(const struct device *dev, u8 reg, u8 value)
> +{
> +	struct oxp_status *state = dev_get_drvdata(dev);
> +	int ret;
> +
> +	if (!state->lock_data.lock(&state->lock_data)) {
> +		dev_warn(dev, "Failed to acquire mutex");
> +		return -EBUSY;
> +	}
> +
> +	ret = ec_write(reg, value);
> +
> +	if (!state->lock_data.unlock(&state->lock_data))
> +		dev_err(dev, "Failed to release mutex");
> +
> +	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;
> +	}
> +	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:
> +			dev_dbg(dev, "Unknown attribute for type %d: %d\n", type, attr);
> +			return -EOPNOTSUPP;
> +		}
> +	case hwmon_pwm:
> +		switch (attr) {
> +		case hwmon_pwm_input:
> +			ret = read_from_ec(OXP_SENSOR_PWM_REG,
> +					   2, val);
> +			*val = (*val * 255) / 100;
> +			return ret;
> +		case hwmon_pwm_enable:
> +			return read_from_ec(OXP_SENSOR_PWM_ENABLE_REG, 1, val);
> +		default:
> +			dev_dbg(dev, "Unknown attribute for type %d: %d\n", type, attr);
> +			return -EOPNOTSUPP;
> +		}
> +	default:
> +		dev_dbg(dev, "Unknown sensor type %d.\n", type);
> +		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);
> +			else
> +				return -EINVAL;
> +		case hwmon_pwm_input:
> +			if (val < 0 || val > 255)
> +				return -EINVAL;
> +			val = (val * 100) / 255;
> +			return write_to_ec(dev, OXP_SENSOR_PWM_REG, val);
> +		default:
> +			dev_dbg(dev, "Unknown attribute for type %d: %d", type, attr);
> +			return -EOPNOTSUPP;
> +		}
> +	default:
> +		dev_dbg(dev, "Unknown sensor type: %d", type);
> +		return -EOPNOTSUPP;
> +	}
> +	return -EINVAL;
> +}
> +
> +/* 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;
> +	struct oxp_status *state;
> +
> +	/* Have to check for AMD processor here */
> +	dmi_entry = dmi_first_match(dmi_table);
> +	if (!dmi_entry || boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
> +		return -ENODEV;
> +
> +	state = devm_kzalloc(dev, sizeof(struct oxp_status), GFP_KERNEL);
> +	if (!state)
> +		return -ENOMEM;
> +
> +	state->lock_data.mutex = 0;
> +	state->lock_data.lock = lock_global_acpi_lock;
> +	state->lock_data.unlock = unlock_global_acpi_lock;
> +
> +	hwdev = devm_hwmon_device_register_with_info(dev, "oxpec", state,
> +							&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);
> +
> +	if (IS_ERR(oxp_platform_device))
> +		return PTR_ERR(oxp_platform_device);
> +
> +	return 0;
> +}
> +
> +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 ACPI EC of OneXPlayer devices");
> +MODULE_LICENSE("GPL");
> --
> 2.38.1
>