Re: [PATCH v3 1/3] hwmon: add initial NXP MC34VR500 PMIC monitoring support

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Jan 17, 2023 at 05:13:38PM +0100, Mario Kicherer wrote:
> This patch adds initial monitoring support for the MC34VR500 PMIC. In its
> current form, input voltage and temperature alarms are reported to hwmon.
> 
> Datasheet:
>  - https://www.nxp.com/docs/en/data-sheet/MC34VR500.pdf
> 
> Changes since v1:
>  - included required #defines directly in the C file
>  - removed separate header file
>  - removed #defines for unimplemented sensors
>  - removed error log output
>  - use hwmon_device_register_with_info API
>  - cleaned probe function
> 
> Signed-off-by: Mario Kicherer <dev@xxxxxxxxxxxx>
> ---
>  drivers/hwmon/Kconfig     |   7 ++
>  drivers/hwmon/Makefile    |   1 +
>  drivers/hwmon/mc34vr500.c | 245 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 253 insertions(+)
>  create mode 100644 drivers/hwmon/mc34vr500.c
> 
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 3176c33af6c6..69d4c1609494 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1166,6 +1166,13 @@ config SENSORS_MAX31790
>  	  This driver can also be built as a module. If so, the module
>  	  will be called max31790.
>  
> +config SENSORS_MC34VR500
> +	tristate "NXP MC34VR500 hardware monitoring driver"
> +	depends on I2C
> +	help
> +	  If you say yes here you get support for the temperature and input
> +	  voltage sensors of the NXP MC34VR500.
> +
>  config SENSORS_MCP3021
>  	tristate "Microchip MCP3021 and compatibles"
>  	depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index e2e4e87b282f..4bef13d16c66 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -149,6 +149,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
>  obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
>  obj-$(CONFIG_SENSORS_MAX31790)	+= max31790.o
>  obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> +obj-$(CONFIG_SENSORS_MC34VR500)	+= mc34vr500.o
>  obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
>  obj-$(CONFIG_SENSORS_TC654)	+= tc654.o
>  obj-$(CONFIG_SENSORS_TPS23861)	+= tps23861.o
> diff --git a/drivers/hwmon/mc34vr500.c b/drivers/hwmon/mc34vr500.c
> new file mode 100644
> index 000000000000..211dc44af42e
> --- /dev/null
> +++ b/drivers/hwmon/mc34vr500.c
> @@ -0,0 +1,245 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * An hwmon driver for the NXP MC34VR500 PMIC
> + *
> + * Author: Mario Kicherer <dev@xxxxxxxxxxxx>
> + */
> +
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>

No longer necessary.

> +#include <linux/i2c.h>
> +#include <linux/regmap.h>

You are sparse with include files. The point is not to include as
few as possible, but to include everything that declares functions
or defines used in the code. I identified some below, but there may
be more missing.

> +
> +#define MC34VR500_I2C_ADDR		0x08
> +#define MC34VR500_DEVICEID_VALUE	0x14
> +
> +/* INTSENSE0 */
> +#define ENS_BIT		BIT(0)
> +#define LOWVINS_BIT	BIT(1)
> +#define THERM110S_BIT	BIT(2)
> +#define THERM120S_BIT	BIT(3)
> +#define THERM125S_BIT	BIT(4)
> +#define THERM130S_BIT	BIT(5)

#include <linux/bits.h>

> +
> +#define MC34VR500_DEVICEID	0x00
> +
> +#define MC34VR500_SILICONREVID	0x03
> +#define MC34VR500_FABID		0x04
> +#define MC34VR500_INTSTAT0	0x05
> +#define MC34VR500_INTMASK0	0x06
> +#define MC34VR500_INTSENSE0	0x07
> +
> +struct mc34vr500_data {
> +	struct device *hwmon_dev;
> +	struct i2c_client *client;

Unused

> +	struct regmap *regmap;
> +};
> +
> +static irqreturn_t mc34vr500_process_interrupt(int irq, void *userdata)

#include <linux/irqreturn.h>

> +{
> +	struct mc34vr500_data *data = (struct mc34vr500_data *)userdata;
> +	unsigned int reg;
> +	int ret;
> +
> +	ret = regmap_read(data->regmap, MC34VR500_INTSTAT0, &reg);
> +	if (ret < 0)
> +		return IRQ_HANDLED;
> +
> +	if (reg) {
> +		if (reg & LOWVINS_BIT)
> +			hwmon_notify_event(data->hwmon_dev, hwmon_in,
> +					   hwmon_in_min_alarm, 0);
> +
> +		if (reg & THERM110S_BIT)
> +			hwmon_notify_event(data->hwmon_dev, hwmon_temp,
> +					   hwmon_temp_max_alarm, 0);
> +
> +		if (reg & THERM120S_BIT)
> +			hwmon_notify_event(data->hwmon_dev, hwmon_temp,
> +					   hwmon_temp_crit_alarm, 0);
> +
> +		if (reg & THERM130S_BIT)
> +			hwmon_notify_event(data->hwmon_dev, hwmon_temp,
> +					   hwmon_temp_emergency_alarm, 0);
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static umode_t mc34vr500_is_visible(const void *data,
> +				    enum hwmon_sensor_types type,
> +				    u32 attr, int channel)
> +{
> +	switch (attr) {
> +	case hwmon_in_min_alarm:
> +	case hwmon_temp_max_alarm:
> +	case hwmon_temp_crit_alarm:
> +	case hwmon_temp_emergency_alarm:
> +		return 0444;
> +	default:
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int mc34vr500_alarm_read(struct mc34vr500_data *data, int index,
> +				long *val)
> +{
> +	unsigned int reg;
> +	int ret;
> +
> +	ret = regmap_read(data->regmap, MC34VR500_INTSTAT0, &reg);
> +	if (ret < 0)
> +		return ret;
> +
> +	*val = !!(reg & index);
> +
> +	/* write 1 to clear */
> +	reg = index;
> +	regmap_write(data->regmap, MC34VR500_INTSTAT0, reg);
> +
> +	return 0;
> +}
> +
> +static int mc34vr500_read(struct device *dev, enum hwmon_sensor_types type,
> +			  u32 attr, int channel, long *val)
> +{
> +	struct mc34vr500_data *data = dev_get_drvdata(dev);

#include <linux/device.h>

> +
> +	switch (type) {
> +	case hwmon_in:
> +		switch (attr) {
> +		case hwmon_in_min_alarm:
> +			return mc34vr500_alarm_read(data, LOWVINS_BIT, val);
> +		default:
> +			return -EOPNOTSUPP;

#include <linux/errno.h>

> +		}
> +	case hwmon_temp:
> +		switch (attr) {
> +		case hwmon_temp_max_alarm:
> +			return mc34vr500_alarm_read(data, THERM110S_BIT, val);
> +		case hwmon_temp_crit_alarm:
> +			return mc34vr500_alarm_read(data, THERM120S_BIT, val);
> +		case hwmon_temp_emergency_alarm:
> +			return mc34vr500_alarm_read(data, THERM130S_BIT, val);
> +		default:
> +			return -EOPNOTSUPP;
> +		}
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static const struct hwmon_channel_info *mc34vr500_info[] = {
> +	HWMON_CHANNEL_INFO(in, HWMON_I_MIN_ALARM),
> +	HWMON_CHANNEL_INFO(temp, HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM
> +			   | HWMON_T_EMERGENCY_ALARM),
> +	NULL,
> +};
> +
> +static const struct hwmon_ops mc34vr500_hwmon_ops = {
> +	.is_visible = mc34vr500_is_visible,
> +	.read = mc34vr500_read,
> +};
> +
> +static const struct hwmon_chip_info mc34vr500_chip_info = {
> +	.ops = &mc34vr500_hwmon_ops,
> +	.info = mc34vr500_info,
> +};
> +
> +static const struct regmap_config mc34vr500_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = MC34VR500_INTSENSE0,
> +};
> +
> +static int mc34vr500_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct mc34vr500_data *data;
> +	struct device *hwmon_dev;
> +	int ret;
> +	unsigned int reg, revid, fabid;
> +	struct regmap *regmap;
> +
> +	regmap = devm_regmap_init_i2c(client, &mc34vr500_regmap_config);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	data = devm_kzalloc(dev, sizeof(struct mc34vr500_data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->regmap = regmap;
> +	data->client = client;
> +
> +	ret = regmap_read(regmap, MC34VR500_DEVICEID, &reg);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (reg != MC34VR500_DEVICEID_VALUE)
> +		return -ENODEV;
> +
> +	ret = regmap_read(regmap, MC34VR500_SILICONREVID, &revid);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regmap_read(regmap, MC34VR500_FABID, &fabid);
> +	if (ret < 0)
> +		return ret;
> +
> +	dev_dbg(dev, "mc34vr500: revid 0x%x fabid 0x%x\n", revid, fabid);

#include <linux/dev_printk.h>

> +
> +	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
> +							 data,
> +							 &mc34vr500_chip_info,
> +							 NULL);
> +	data->hwmon_dev = hwmon_dev;
> +
> +	if (client->irq) {

This would still request and enable interrupts after registering the hwmon
device failed for whatever reason. If an interrupt then occurs before the
probe function actually fails, hwmon_notify_event() would be called with
a bad hwmon device pointer and crash.

The return value from devm_hwmon_device_register_with_info() needs to be
checked before the interrupt is enabled.

> +		ret = devm_request_threaded_irq(dev, client->irq, NULL,
> +						mc34vr500_process_interrupt,
> +						IRQF_TRIGGER_RISING |
> +						IRQF_ONESHOT |
> +						IRQF_SHARED,
> +						dev_name(dev), data);

#include <linux/interrupt.h>

> +		if (ret)
> +			return ret;
> +
> +		/* clear interrupts */
> +		ret = regmap_write(regmap, MC34VR500_INTSTAT0, 0);
> +		if (ret)
> +			return ret;
> +
> +		/* unmask interrupts */
> +		ret = regmap_write(regmap, MC34VR500_INTMASK0,
> +				   ~(LOWVINS_BIT | THERM110S_BIT));

Why not enable the other handled thermal event bits ?

> +		if (ret)
> +			return ret;
> +	}
> +
> +	return PTR_ERR_OR_ZERO(hwmon_dev);

Then this can just return 0. Also

#include <linux/err.h>

for both PTR_ERR_OR_ZERO() and PTR_ERR().

> +}
> +
> +static const struct i2c_device_id mc34vr500_id[] = {
> +	{ "mc34vr500", 0 },
> +	{ }
> +};
> +

Drop this empty line

> +MODULE_DEVICE_TABLE(i2c, mc34vr500_id);

#include <linux/module.h>

> +

What happened with nxp,mc34vr500 ? You'll need the devicetree
match to instantiate the device in devicetree systems.

> +static struct i2c_driver mc34vr500_driver = {
> +	.driver = {
> +		   .name = "mc34vr500",
> +		    },
> +	.probe_new = mc34vr500_probe,
> +	.id_table = mc34vr500_id,
> +};
> +
> +module_i2c_driver(mc34vr500_driver);
> +
> +MODULE_AUTHOR("Mario Kicherer <dev@xxxxxxxxxxxx>");
> +
> +MODULE_DESCRIPTION("MC34VR500 driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.34.1
> 



[Index of Archives]     [LM Sensors]     [Linux Sound]     [ALSA Users]     [ALSA Devel]     [Linux Audio Users]     [Linux Media]     [Kernel]     [Gimp]     [Yosemite News]     [Linux Media]

  Powered by Linux