Re: [PATCH v2 2/3] hwmon: (pmbus): Add POWER system power supply driver

[Guenter Roeck]

On Thu, Aug 10, 2017 at 05:19:45PM -0500, Eddie James wrote:
> From: "Edward A. James" <eajames@xxxxxxxxxx>
> 
> Add the driver to monitor POWER system power supplies with hwmon over
> pmbus.
> 
> Signed-off-by: Edward A. James <eajames@xxxxxxxxxx>
> ---
>  drivers/hwmon/pmbus/Kconfig   |  10 +++
>  drivers/hwmon/pmbus/Makefile  |   1 +
>  drivers/hwmon/pmbus/powerps.c | 144 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 155 insertions(+)
>  create mode 100644 drivers/hwmon/pmbus/powerps.c
> 
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 68d717a..8925c1a 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -125,6 +125,16 @@ config SENSORS_MAX8688
>  	  This driver can also be built as a module. If so, the module will
>  	  be called max8688.
>  
> +config SENSORS_POWERPS
> +	tristate "IBM POWER System Power Supply"
> +	default n
> +	help
> +	  If you say yes here you get hardware monitoring support for the IBM
> +	  POWER system power supply.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called powerps.
> +
>  config SENSORS_TPS40422
>  	tristate "TI TPS40422"
>  	default n
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 75bb7ca..3303af5 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_SENSORS_MAX16064)	+= max16064.o
>  obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o
>  obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
>  obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
> +obj-$(CONFIG_SENSORS_POWERPS)	+= powerps.o
>  obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
>  obj-$(CONFIG_SENSORS_UCD9000)	+= ucd9000.o
>  obj-$(CONFIG_SENSORS_UCD9200)	+= ucd9200.o
> diff --git a/drivers/hwmon/pmbus/powerps.c b/drivers/hwmon/pmbus/powerps.c
> new file mode 100644
> index 0000000..21d28f2
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/powerps.c
> @@ -0,0 +1,144 @@
> +/*
> + * Copyright 2017 IBM Corp.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/i2c.h>
> +#include <linux/jiffies.h>
> +#include <linux/module.h>
> +
> +#include "pmbus.h"
> +
> +/* STATUS_MFR_SPECIFIC bits */
> +#define POWERPS_MFR_FAN_FAULT			BIT(0)
> +#define POWERPS_MFR_THERMAL_FAULT		BIT(1)
> +#define POWERPS_MFR_OV_FAULT			BIT(2)
> +#define POWERPS_MFR_UV_FAULT			BIT(3)
> +#define POWERPS_MFR_PS_KILL			BIT(4)
> +#define POWERPS_MFR_OC_FAULT			BIT(5)
> +#define POWERPS_MFR_VAUX_FAULT			BIT(6)
> +#define POWERPS_MFR_CURRENT_SHARE_WARNING	BIT(7)
> +
> +static int powerps_read_byte_data(struct i2c_client *client, int page, int reg)
> +{
> +	int rc, mfr;
> +
> +	switch (reg) {
> +	case PMBUS_STATUS_VOUT:
> +	case PMBUS_STATUS_IOUT:
> +	case PMBUS_STATUS_TEMPERATURE:
> +	case PMBUS_STATUS_FAN_12:
> +		rc = pmbus_read_byte_data(client, page, reg);
> +		if (rc < 0)
> +			return rc;
> +
> +		mfr = pmbus_read_byte_data(client, page,
> +					   PMBUS_STATUS_MFR_SPECIFIC);
> +		if (mfr < 0)
> +			return rc;

			return mfr; ?

> +
> +		/* Add MFR_SPECIFIC bits to the standard pmbus status regs. */
> +		if (reg == PMBUS_STATUS_FAN_12) {
> +			if (mfr & POWERPS_MFR_FAN_FAULT)
> +				rc |= PB_FAN_FAN1_FAULT;
> +		} else if (reg == PMBUS_STATUS_TEMPERATURE) {
> +			if (mfr & POWERPS_MFR_THERMAL_FAULT)
> +				rc |= PB_TEMP_OT_FAULT;
> +		} else if (reg == PMBUS_STATUS_VOUT) {
> +			if (mfr &
> +			    (POWERPS_MFR_OV_FAULT | POWERPS_MFR_VAUX_FAULT))

Wondering - this suggests that there is a VAUX. Would it make sense
to map it to PMBUS_VIRT_READ_VMON ?

> +				rc |= PB_VOLTAGE_OV_FAULT;
> +			if (mfr & POWERPS_MFR_UV_FAULT)
> +				rc |= PB_VOLTAGE_UV_FAULT;
> +		} else if (reg == PMBUS_STATUS_IOUT) {
> +			if (mfr & POWERPS_MFR_OC_FAULT)
> +				rc |= PB_IOUT_OC_FAULT;
> +			if (mfr & POWERPS_MFR_CURRENT_SHARE_WARNING)
> +				rc |= PB_CURRENT_SHARE_FAULT;
> +		}
> +		break;
> +	default:
> +		rc = -ENODATA;
> +		break;
> +	}
> +
> +	return rc;
> +}
> +
> +static int powerps_read_word_data(struct i2c_client *client, int page, int reg)
> +{
> +	int rc, mfr;
> +
> +	switch (reg) {
> +	case PMBUS_STATUS_WORD:
> +		rc = pmbus_read_word_data(client, page, reg);
> +		if (rc < 0)
> +			return rc;
> +
> +		mfr = pmbus_read_byte_data(client, page,
> +					   PMBUS_STATUS_MFR_SPECIFIC);
> +		if (mfr < 0)
> +			return rc;

			return mfr; ?

> +
> +		if (mfr & POWERPS_MFR_PS_KILL)
> +			rc |= PB_STATUS_OFF;
> +		break;
> +	default:
> +		rc = -ENODATA;
> +		break;
> +	}
> +
> +	return rc;
> +}
> +
> +static struct pmbus_driver_info powerps_info = {
> +	.pages = 1,
> +	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
> +		PMBUS_HAVE_PIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP |
> +		PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_VOUT |
> +		PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT |
> +		PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_FAN12,
> +	.read_byte_data = powerps_read_byte_data,
> +	.read_word_data = powerps_read_word_data,
> +	.debugfs = true,
> +};
> +
> +static int powerps_probe(struct i2c_client *client,
> +			 const struct i2c_device_id *id)
> +{
> +	return pmbus_do_probe(client, id, &powerps_info);
> +}
> +
> +static const struct i2c_device_id powerps_id[] = {
> +	{ "power_ps", 1 },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, powerps_id);
> +
> +/* IBM provides many compatible power supplies; use a generic name. */
> +static const struct of_device_id powerps_of_match[] = {
> +	{ .compatible = "ibm,power-ps" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, powerps_of_match);
> +
> +static struct i2c_driver powerps_driver = {
> +	.driver = {
> +		.name = "powerps",
> +		.of_match_table = powerps_of_match,
> +	},
> +	.probe = powerps_probe,
> +	.remove = pmbus_do_remove,
> +	.id_table = powerps_id,
> +};
> +
> +module_i2c_driver(powerps_driver);
> +
> +MODULE_AUTHOR("Eddie James");
> +MODULE_DESCRIPTION("PMBus driver for POWER system power supplies");
> +MODULE_LICENSE("GPL");
> -- 
> 1.8.3.1
>