Re: [PATCH v5] hwmon: Add driver for STMicroelectronics PM6764 Voltage Regulator

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

On Fri, Nov 27, 2020 at 09:59:01AM +0800, Charles wrote:
> Add the pmbus driver for the STMicroelectronics pm6764 voltage regulator.
> 
> the output voltage use the MFR_READ_VOUT 0xD4
> vout value returned is linear11
> 
> Signed-off-by: Charles Hsu <hsu.yungteng@gmail.com>

This patch (again) didn't make it to any of the mailing lists.
Please try to find out why this is the case. I usually pick up
patches from https://patchwork.kernel.org/project/linux-hwmon/list/,
and may easily miss a patch if I can't find it there.

> ---
> 
> v5:
>  - Add MAINTAINERS
>  - Add a reference into trivial-devices.yaml
> v4:
>  - Add pm6764tr to Documentation/hwmon/index.rst.
> v3:
>  - Add Documentation(Documentation/hwmon/pm6764tr.rst).
>  - Fix include order.
> v2:
>  - Fix formatting.
>  - Remove pmbus_do_remove.
>  - Change from .probe to .probe_new.
> v1:
>  - Initial patchset.
> 
> ---
> 
>  .../devicetree/bindings/trivial-devices.yaml  |  2 +
>  Documentation/hwmon/index.rst                 |  1 +
>  Documentation/hwmon/pm6764tr.rst              | 33 ++++++++
>  MAINTAINERS                                   |  7 ++
>  drivers/hwmon/pmbus/Kconfig                   |  9 +++
>  drivers/hwmon/pmbus/Makefile                  |  1 +
>  drivers/hwmon/pmbus/pm6764tr.c                | 76 +++++++++++++++++++
>  7 files changed, 129 insertions(+)
>  create mode 100644 Documentation/hwmon/pm6764tr.rst
>  create mode 100644 drivers/hwmon/pmbus/pm6764tr.c
> 
> diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
> index ab623ba930d5..cdd7bdb6abbb 100644
> --- a/Documentation/devicetree/bindings/trivial-devices.yaml
> +++ b/Documentation/devicetree/bindings/trivial-devices.yaml
> @@ -348,6 +348,8 @@ properties:
>            - socionext,synquacer-tpm-mmio
>              # i2c serial eeprom  (24cxx)
>            - st,24c256
> +            # SMBus/I2C Voltage Regulator
> +          - st,pm6764tr
>              # Ambient Light Sensor with SMBUS/Two Wire Serial Interface
>            - taos,tsl2550
>              # 8-Channels, 12-bit ADC

This, like all devicetre changes, needs to be a separate patch.
Also, please make sure to copy dt maintainers and the dt mailing list
when you send that patch.

> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index b797db738225..1bbd05e41de4 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -144,6 +144,7 @@ Hardware Monitoring Kernel Drivers
>     pc87360
>     pc87427
>     pcf8591
> +   pm6764tr
>     pmbus
>     powr1220
>     pxe1610
> diff --git a/Documentation/hwmon/pm6764tr.rst b/Documentation/hwmon/pm6764tr.rst
> new file mode 100644
> index 000000000000..5e8092e39297
> --- /dev/null
> +++ b/Documentation/hwmon/pm6764tr.rst
> @@ -0,0 +1,33 @@
> +.. SPDX-License-Identifier: GPL-2.0-only
> +
> +Kernel driver pm6764tr
> +======================
> +
> +Supported chips:
> +
> +  * ST PM6764TR
> +
> +    Prefix: 'pm6764tr'
> +
> +    Addresses scanned: -
> +
> +    Datasheet: http://www.st.com/resource/en/data_brief/pm6764.pdf
> +
> +Authors:
> +	<hsu.yungteng@gmail.com>
> +
> +Description:
> +------------
> +
> +This driver supports the STMicroelectronics PM6764TR chip. The PM6764TR is a high
> +performance digital controller designed to power Intel’s VR12.5 processors and memories.
> +

Unrelated side note: I understand this means that you are forced to keep the
datasheet under wraps, which in turn means I can not suggest functionality
improvements since I don't have access to it. If the chip happens to support
per-rail telemetry, you might want to consider adding support for that in a
follow-up patch.

> +The device utilizes digital technology to implement all control and power management
> +functions to provide maximum flexibility and performance. The NVM is embedded to store
> +custom configurations. The PM6764TR device features up to 4-phase programmable operation.
> +
> +The PM6764TR supports power state transitions featuring VFDE, and programmable DPM
> +maintaining the best efficiency over all loading conditions without compromising transient
> +response. The device assures fast and independent protectionagainstload overcurrent,

"protectionagainstload" -> "protection against load"

> +under/overvoltage and feedback disconnections.
> +

Drop empty line at end.

> diff --git a/MAINTAINERS b/MAINTAINERS
> index 94ac10a153c7..a3fea132c4ed 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13904,6 +13904,13 @@ M:	Logan Gunthorpe <logang@deltatee.com>
>  S:	Maintained
>  F:	drivers/dma/plx_dma.c

Add empty line.

> +PM6764TR DRIVER
> +M:	Charles Hsu	<hsu.yungteng@gmail.com>
> +L:	linux-hwmon@vger.kernel.org
> +S:	Maintained
> +F:	Documentation/hwmon/pm6764tr.rst
> +F:	drivers/hwmon/pmbus/pm6764tr.c
> +
>  PM-GRAPH UTILITY
>  M:	"Todd E Brandt" <todd.e.brandt@linux.intel.com>
>  L:	linux-pm@vger.kernel.org
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index a25faf69fce3..9c846facce9f 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -220,6 +220,15 @@ config SENSORS_MP2975
>  	  This driver can also be built as a module. If so, the module will
>  	  be called mp2975.

Add empty line.

> +config SENSORS_PM6764TR
> +	tristate "ST PM6764TR"
> +	help
> +	  If you say yes here you get hardware monitoring support for ST
> +	  PM6764TR.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called pm6764tr.
> +
>  config SENSORS_PXE1610
>  	tristate "Infineon PXE1610"
>  	help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 4c97ad0bd791..31ebdef5d4a6 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -25,6 +25,7 @@ obj-$(CONFIG_SENSORS_MAX31785)	+= max31785.o
>  obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
>  obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
>  obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o
> +obj-$(CONFIG_SENSORS_PM6764TR)	+= pm6764tr.o
>  obj-$(CONFIG_SENSORS_PXE1610)	+= pxe1610.o
>  obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
>  obj-$(CONFIG_SENSORS_TPS53679)	+= tps53679.o
> diff --git a/drivers/hwmon/pmbus/pm6764tr.c b/drivers/hwmon/pmbus/pm6764tr.c
> new file mode 100644
> index 000000000000..70747c21c66e
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/pm6764tr.c
> @@ -0,0 +1,76 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Hardware monitoring driver for STMicroelectronics digital controller PM6764TR
> + */
> +
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pmbus.h>
> +#include "pmbus.h"
> +
> +#define PM6764TR_PMBUS_READ_VOUT	0xD4
> +
> +static int pm6764tr_read_word_data(struct i2c_client *client, int page, int reg)
> +{
> +	int ret;
> +
> +	switch (reg) {
> +	case PMBUS_VIRT_READ_VMON:
> +		ret = pmbus_read_word_data(client, page, PM6764TR_PMBUS_READ_VOUT);
> +		break;
> +	default:
> +		ret = -ENODATA;
> +		break;
> +	}
> +	return ret;
> +}
> +
> +static struct pmbus_driver_info pm6764tr_info = {
> +	.pages = 1,
> +	.format[PSC_VOLTAGE_IN] = linear,
> +	.format[PSC_VOLTAGE_OUT] = vid,
> +	.format[PSC_TEMPERATURE] = linear,
> +	.format[PSC_CURRENT_OUT] = linear,
> +	.format[PSC_POWER] = linear,
> +	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN |  PMBUS_HAVE_PIN |
> +	    PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT | PMBUS_HAVE_VMON |
> +		PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_VOUT |
> +		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
> +	.read_word_data = pm6764tr_read_word_data,
> +};
> +
> +static int pm6764tr_probe(struct i2c_client *client,
> +			  const struct i2c_device_id *id)
> +{
> +	return pmbus_do_probe(client, id, &pm6764tr_info);
> +}
> +
> +static const struct i2c_device_id pm6764tr_id[] = {
> +	{"pm6764tr", 0},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, pm6764tr_id);
> +
> +static const struct of_device_id pm6764tr_of_match[] = {
> +	{.compatible = "st,pm6764tr"},
> +	{}
> +};
> +
> +/* This is the driver that will be inserted */
> +static struct i2c_driver pm6764tr_driver = {
> +	.driver = {
> +		   .name = "pm6764tr",
> +		   .of_match_table = of_match_ptr(pm6764tr_of_match),
> +		   },
> +	.probe_new = pm6764tr_probe,
> +	.id_table = pm6764tr_id,
> +};
> +
> +module_i2c_driver(pm6764tr_driver);
> +
> +MODULE_AUTHOR("Charles Hsu");
> +MODULE_DESCRIPTION("PMBus driver for  ST PM6764TR");
> +MODULE_LICENSE("GPL");
> -- 
> 2.25.1
>