[PATCH v3 1/2] hwmon: (pmbus) Add Delta AHE-50DC fan control module driver

Guenter Roeck linux at roeck-us.net
Wed Dec 8 04:50:15 AEDT 2021


On Mon, Dec 06, 2021 at 11:15:20PM -0800, Zev Weiss wrote:
> This device is an integrated module of the Delta AHE-50DC Open19 power
> shelf.  For lack of proper documentation, this driver has been developed
> referencing an existing (GPL) driver that was included in a code release
> from LinkedIn [1].  It provides four fan speeds, four temperatures, and
> one voltage reading, as well as a handful of warning and fault
> indicators.
> 
> [1] https://github.com/linkedin/o19-bmc-firmware/blob/master/meta-openbmc/meta-linkedin/meta-deltapower/recipes-kernel/fancontrol-mod/files/fancontrol.c
> 

Hmm, that reference isn't really accurate anymore. I think it would be
better to just say that the device was found to be PMBus compliant.

> Signed-off-by: Zev Weiss <zev at bewilderbeest.net>
> ---
>  MAINTAINERS                             |  6 ++
>  drivers/hwmon/pmbus/Kconfig             | 12 ++++
>  drivers/hwmon/pmbus/Makefile            |  1 +
>  drivers/hwmon/pmbus/delta-ahe50dc-fan.c | 84 +++++++++++++++++++++++++
>  4 files changed, 103 insertions(+)
>  create mode 100644 drivers/hwmon/pmbus/delta-ahe50dc-fan.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0ac052200ecb..8bb7ba52d2f5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5425,6 +5425,12 @@ W:	https://linuxtv.org
>  T:	git git://linuxtv.org/media_tree.git
>  F:	drivers/media/platform/sti/delta
>  
> +DELTA AHE-50DC FAN CONTROL MODULE DRIVER
> +M:	Zev Weiss <zev at bewilderbeest.net>
> +L:	linux-hwmon at vger.kernel.org
> +S:	Maintained
> +F:	drivers/hwmon/pmbus/delta-ahe50dc-fan.c
> +
>  DELTA DPS920AB PSU DRIVER
>  M:	Robert Marko <robert.marko at sartura.hr>
>  L:	linux-hwmon at vger.kernel.org
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index ffb609cee3a4..937e1c2c11e7 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -66,6 +66,18 @@ config SENSORS_BPA_RS600
>  	  This driver can also be built as a module. If so, the module will
>  	  be called bpa-rs600.
>  
> +config SENSORS_DELTA_AHE50DC_FAN
> +	tristate "Delta AHE-50DC fan control module"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  If you say yes here you get hardware monitoring support for
> +	  the integrated fan control module of the Delta AHE-50DC
> +	  Open19 power shelf.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called delta-ahe50dc-fan.
> +
>  config SENSORS_FSP_3Y
>  	tristate "FSP/3Y-Power power supplies"
>  	help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 0ed4d596a948..a56b2897288d 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_BPA_RS600)	+= bpa-rs600.o
> +obj-$(CONFIG_SENSORS_DELTA_AHE50DC_FAN) += delta-ahe50dc-fan.o
>  obj-$(CONFIG_SENSORS_FSP_3Y)	+= fsp-3y.o
>  obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
>  obj-$(CONFIG_SENSORS_DPS920AB)	+= dps920ab.o
> diff --git a/drivers/hwmon/pmbus/delta-ahe50dc-fan.c b/drivers/hwmon/pmbus/delta-ahe50dc-fan.c
> new file mode 100644
> index 000000000000..07b1e7c5f5f5
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/delta-ahe50dc-fan.c
> @@ -0,0 +1,84 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Delta AHE-50DC power shelf fan control module driver
> + *
> + * Copyright 2021 Zev Weiss <zev at bewilderbeest.net>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/pmbus.h>

Alphabetic include file order please.

> +
> +#include "pmbus.h"
> +
> +#define AHE50DC_PMBUS_READ_TEMP4 0xd0
> +
> +static int ahe50dc_fan_read_word_data(struct i2c_client *client, int page, int phase, int reg)
> +{
> +	/* temp1 in (virtual) page 1 is remapped to mfr-specific temp4 */
> +	if (page == 1) {
> +		if (reg == PMBUS_READ_TEMPERATURE_1)
> +			return i2c_smbus_read_word_data(client, AHE50DC_PMBUS_READ_TEMP4);
> +		return -EOPNOTSUPP;
> +	}
> +	return -ENODATA;
> +}
> +
> +static struct pmbus_driver_info ahe50dc_fan_info = {
> +	.pages = 2,
> +	.format[PSC_FAN] = direct,
> +	.format[PSC_TEMPERATURE] = direct,
> +	.format[PSC_VOLTAGE_IN] = direct,
> +	.m[PSC_FAN] = 1,
> +	.b[PSC_FAN] = 0,
> +	.R[PSC_FAN] = 0,
> +	.m[PSC_TEMPERATURE] = 1,
> +	.b[PSC_TEMPERATURE] = 0,
> +	.R[PSC_TEMPERATURE] = 1,
> +	.m[PSC_VOLTAGE_IN] = 1,
> +	.b[PSC_VOLTAGE_IN] = 0,
> +	.R[PSC_VOLTAGE_IN] = 3,

How did you determine the exponents ? The referenced driver
doesn't seem to make a difference between voltage and temperature
exponents (nor fan speed, which is a bit odd).

> +	.func[0] = PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
> +		PMBUS_HAVE_VIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_FAN34 |
> +		PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_STATUS_FAN34 | PMBUS_PAGE_VIRTUAL,
> +	.func[1] = PMBUS_HAVE_TEMP | PMBUS_PAGE_VIRTUAL,
> +	.read_word_data = ahe50dc_fan_read_word_data,
> +};
> +
> +static struct pmbus_platform_data ahe50dc_fan_data = {
> +	.flags = PMBUS_NO_CAPABILITY,
> +};

Is that necessary ? It should only be used if trying to read CAPABILITY
reports bad data.

Thanks,
Guenter

> +
> +static int ahe50dc_fan_probe(struct i2c_client *client)
> +{
> +	client->dev.platform_data = &ahe50dc_fan_data;
> +	return pmbus_do_probe(client, &ahe50dc_fan_info);
> +}
> +
> +static const struct i2c_device_id ahe50dc_fan_id[] = {
> +	{ "ahe50dc_fan" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ahe50dc_fan_id);
> +
> +static const struct of_device_id __maybe_unused ahe50dc_fan_of_match[] = {
> +	{ .compatible = "delta,ahe50dc-fan" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, ahe50dc_fan_of_match);
> +
> +static struct i2c_driver ahe50dc_fan_driver = {
> +	.driver = {
> +		   .name = "ahe50dc_fan",
> +		   .of_match_table = of_match_ptr(ahe50dc_fan_of_match),
> +	},
> +	.probe_new = ahe50dc_fan_probe,
> +	.id_table = ahe50dc_fan_id,
> +};
> +module_i2c_driver(ahe50dc_fan_driver);
> +
> +MODULE_AUTHOR("Zev Weiss <zev at bewilderbeest.net>");
> +MODULE_DESCRIPTION("Driver for Delta AHE-50DC power shelf fan control module");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS(PMBUS);
> -- 
> 2.34.1
> 


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