Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU

[Guenter Roeck]

On Fri, Apr 30, 2021 at 03:27:33PM +0200, Robert Marko wrote:
> This adds support for the Delta DPS-920AB PSU.
> 
> Only missing feature is fan control which the PSU supports.
> 
> Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
> ---
>  Documentation/hwmon/dps920ab.rst | 80 ++++++++++++++++++++++++++++++++
>  Documentation/hwmon/index.rst    |  1 +
>  drivers/hwmon/pmbus/Kconfig      |  9 ++++
>  drivers/hwmon/pmbus/Makefile     |  1 +
>  drivers/hwmon/pmbus/dps920ab.c   | 63 +++++++++++++++++++++++++
>  5 files changed, 154 insertions(+)
>  create mode 100644 Documentation/hwmon/dps920ab.rst
>  create mode 100644 drivers/hwmon/pmbus/dps920ab.c
> 
> diff --git a/Documentation/hwmon/dps920ab.rst b/Documentation/hwmon/dps920ab.rst
> new file mode 100644
> index 000000000000..df0aef530c7e
> --- /dev/null
> +++ b/Documentation/hwmon/dps920ab.rst
> @@ -0,0 +1,80 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +Kernel driver dps920ab
> +========================
> +
> +Supported chips:
> +
> +  * Delta DPS920AB
> +
> +    Prefix: 'dps920ab'
> +
> +    Addresses scanned: -
> +
> +Authors:
> +    Robert Marko <robert.marko@xxxxxxxxxx>
> +
> +
> +Description
> +-----------
> +
> +This driver implements support for Delta DPS920AB 920W 54V DC single output
> +power supply with PMBus support.
> +
> +The driver is a client driver to the core PMBus driver.
> +Please see Documentation/hwmon/pmbus.rst for details on PMBus client drivers.
> +
> +
> +Usage Notes
> +-----------
> +
> +This driver does not auto-detect devices. You will have to instantiate the
> +devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
> +details.
> +
> +
> +Sysfs entries
> +-------------
> +
> +======================= ======================================================
> +curr1_label		"iin"
> +curr1_input		Measured input current
> +curr1_crit		Critical maximum current
> +curr1_crit_alarm	Current critical high alarm
> +
> +curr2_label		"iout1"
> +curr2_input		Measured output current
> +curr2_crit		Critical maximum current
> +curr2_crit_alarm	Current critical high alarm
> +
> +in1_label		"vin"
> +in1_input		Measured input voltage
> +in1_lcrit		Critical minimum input voltage
> +in1_lcrit_alarm		Input voltage critical low alarm
> +in1_crit		Critical maximum input voltage
> +in1_crit_alarm		Input voltage critical high alarm
> +
> +in2_label		"vout1"
> +in2_input		Measured output voltage
> +in2_lcrit		Critical minimum output voltage
> +in2_lcrit_alarm		Output voltage critical low alarm
> +in2_crit		Critical maximum output voltage
> +in2_crit_alarm		Output voltage critical high alarm
> +
> +power1_label		"pin"
> +power1_input		Measured input power
> +power1_alarm		Input power high alarm
> +
> +power2_label		"pout1"
> +power2_input		Measured output power
> +
> +temp[1-2]_input		Measured temperature
> +temp[1-2]_crit		Critical high temperature
> +temp[1-2]_crit_alarm	Chip temperature critical high alarm
> +temp[1-2]_max		Maximum temperature
> +temp[1-2]_max_alarm	Chip temperature high alarm
> +
> +fan1_alarm		Fan 1 warning.
> +fan1_fault		Fan 1 fault.
> +fan1_input		Fan 1 speed in RPM.
> +======================= ======================================================
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index 8d5a2df1ecb6..b24436f22052 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -54,6 +54,7 @@ Hardware Monitoring Kernel Drivers
>     dell-smm-hwmon
>     dme1737
>     drivetemp
> +   dps920ab
>     ds1621
>     ds620
>     emc1403
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 32d2fc850621..865ade0aa205 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -66,6 +66,15 @@ config SENSORS_IBM_CFFPS
>  	  This driver can also be built as a module. If so, the module will
>  	  be called ibm-cffps.
>  
> +config SENSORS_DPS920AB
> +	tristate "Delta DPS920AB Power Supply"
> +	help
> +	  If you say yes here you get hardware monitoring support for Delta
> +	  DPS920AB Power Supplies.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called dps920ab.
> +
>  config SENSORS_INSPUR_IPSPS
>  	tristate "INSPUR Power System Power Supply"
>  	help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 6a4ba0fdc1db..f59ba0123d68 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_SENSORS_ADM1266)	+= adm1266.o
>  obj-$(CONFIG_SENSORS_ADM1275)	+= adm1275.o
>  obj-$(CONFIG_SENSORS_BEL_PFE)	+= bel-pfe.o
>  obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
> +obj-$(CONFIG_SENSORS_DPS920AB)	+= dps920ab.o
>  obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
>  obj-$(CONFIG_SENSORS_IR35221)	+= ir35221.o
>  obj-$(CONFIG_SENSORS_IR38064)	+= ir38064.o
> diff --git a/drivers/hwmon/pmbus/dps920ab.c b/drivers/hwmon/pmbus/dps920ab.c
> new file mode 100644
> index 000000000000..d579ed9f879c
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/dps920ab.c
> @@ -0,0 +1,63 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Driver for Delta DPS920AB PSU
> + *
> + * Copyright (C) 2021 Delta Networks, Inc.
> + * Copyright (C) 2021 Sartura Ltd.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include "pmbus.h"
> +
> +static struct pmbus_driver_info dps920ab_info = {
> +	.pages = 1,
> +
> +	.format[PSC_VOLTAGE_IN] = linear,
> +	.format[PSC_VOLTAGE_OUT] = linear,
> +	.format[PSC_CURRENT_IN] = linear,
> +	.format[PSC_CURRENT_OUT] = linear,
> +	.format[PSC_POWER] = linear,
> +	.format[PSC_FAN] = linear,
> +	.format[PSC_TEMPERATURE] = linear,
> +
> +	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN  |
> +	PMBUS_HAVE_VOUT  | PMBUS_HAVE_STATUS_VOUT   |
> +	PMBUS_HAVE_IOUT  | PMBUS_HAVE_STATUS_IOUT   |
> +	PMBUS_HAVE_TEMP  | PMBUS_HAVE_TEMP2         |
> +	PMBUS_HAVE_PIN   | PMBUS_HAVE_POUT          |
> +	PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12  |
> +	PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
> +};
> +
> +static int dps920ab_probe(struct i2c_client *client)
> +{
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_BYTE_DATA |
> +				     I2C_FUNC_SMBUS_WORD_DATA))
> +		return -ENODEV;

This check is done in pmbus_do_probe(), and repeating it here does not add
any value.

That makes me wonder: Is this driver needed in the first place, or could
it be added to drivers/hwmon/pmbus/pmbus.c ?

Thanks,
Guenter

> +
> +	return pmbus_do_probe(client, &dps920ab_info);
> +}
> +
> +static const struct of_device_id __maybe_unused dps920ab_of_match[] = {
> +	{ .compatible = "delta,dps920ab", },
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(of, dps920ab_of_match);
> +
> +static struct i2c_driver dps920ab_driver = {
> +	.driver = {
> +		   .name = "dps920ab",
> +		   .of_match_table = of_match_ptr(dps920ab_of_match),
> +	},
> +	.probe_new = dps920ab_probe,
> +};
> +
> +module_i2c_driver(dps920ab_driver);
> +
> +MODULE_AUTHOR("Robert Marko <robert.marko@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("PMBus driver for Delta DPS920AB PSU");
> +MODULE_LICENSE("GPL");
> -- 
> 2.31.1
>