Re: [PATCH v4] hwmon:Driver for Delta power supplies

[Guenter Roeck]

On Wed, Sep 23, 2020 at 11:48:05AM +0100, xiao.mx.ma wrote:
> From: Delta <xiao.mx.ma@xxxxxxxxxxx>
> 
> The <drivers/hwmon/pmbus/delta.c> provides a driver for Delta's modules.
> Currently supports Q54SJ108A2 series and other series will continue to be
> added in the future. And some customize functions such as R/W blackbox and
> bootloader will be added in next revision.
> 
> Signed-off-by: Delta <xiao.mx.ma@xxxxxxxxxxx>
> 
> --Patch v2 changelog:
> 	Add delta.rst in Documentation/hwmon.
> 	Tristate "DELTA" in Kconfig is changed to "DELTA_POWER_SUPPLIES".
> 	Modify code: drop the excessive empty lines, correct the comment
> content, adjust indent, remove extra brackets.
> --Patch v3 changelog:
> 	Add delta.rst to Documentation/hwmon/index.rst.
> 	Tristate "DELTA_POWER_SUPPLIES" in Kconfig is changed to "Delta
> Power Supplies".
> --Patch v4 changelog:
> 	Correct the spelling 'Temperature' in the delta.rst.
> 	Add Write_protect when write command VOUT_OV_FAULT_RESPONSE and
> IOUT_OC_FAULT_RESPONSE.
> ---

Change log goes here (after ---)

>  Documentation/hwmon/delta.rst |  52 ++++++++++++
>  Documentation/hwmon/index.rst |   1 +
>  drivers/hwmon/pmbus/Kconfig   |   9 ++
>  drivers/hwmon/pmbus/Makefile  |   1 +
>  drivers/hwmon/pmbus/delta.c   | 153 ++++++++++++++++++++++++++++++++++
>  5 files changed, 216 insertions(+)
>  create mode 100644 Documentation/hwmon/delta.rst
>  create mode 100644 drivers/hwmon/pmbus/delta.c
> 
> diff --git a/Documentation/hwmon/delta.rst b/Documentation/hwmon/delta.rst
> new file mode 100644
> index 000000000000..225cc9ddfa00
> --- /dev/null
> +++ b/Documentation/hwmon/delta.rst
> @@ -0,0 +1,52 @@
> +Kernel driver delta
> +=====================
> +
> +Supported chips:
> +
> +  * DELTA Q54SJ108A2NCAH, Q54SJ108A2NCDH, Q54SJ108A2NCPG, Q54SJ108A2NCPH
> +
> +    Prefix: 'Q54SJ108A2'
> +
> +    Addresses scanned: -
> +
> +    Datasheet: https://filecenter.delta-china.com.cn/products/download/01/0102/datasheet/DS_Q54SJ108A2.pdf
> +
> +Authors:
> +    Delta <xiao.mx.ma@xxxxxxxxxxx>
> +
> +
> +Description
> +-----------
> +
> +This driver implements support for DELTA Q54SJ108A2NCAH, Q54SJ108A2NCDH, 
> +Q54SJ108A2NCPG, and Q54SJ108A2NCPH 1/4 Brick DC/DC Regulated Power Module 
> +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_alarm         RO    Output current alarm
> +curr1_input         RO    Output current
> +curr1_label         RO    'iout1'
> +in1_alarm           RO    Input voltage alarm
> +in1_input           RO    Input voltage
> +in1_label           RO    'vin'
> +in2_alarm           RO    Output voltage alarm
> +in2_input           RO    Output voltage
> +in2_label           RO    'vout1'
> +temp1_alarm         RO    Temperature alarm
> +temp1_input         RO    Chip temperature
> +=================== ===== =======================================================
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index 750d3a975d82..31c51545df72 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -51,6 +51,7 @@ Hardware Monitoring Kernel Drivers
>     da9052
>     da9055
>     dell-smm-hwmon
> +   delta
>     dme1737
>     drivetemp
>     ds1621
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index e35db489b76f..9b1863bfa946 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -44,6 +44,15 @@ config SENSORS_BEL_PFE
>  
>  	  This driver can also be built as a module. If so, the module will
>  	  be called bel-pfe.
> +	  
> +config SENSORS_DELTA
> +	tristate "Delta Power Supplies"
> +	help
> +	  If you say yes here you get hardware monitoring support for Delta
> +	  Q54SJ108A2 series Power Supplies.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called delta.
>  
>  config SENSORS_IBM_CFFPS
>  	tristate "IBM Common Form Factor Power Supply"
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index c4b15db996ad..8957f5337002 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -7,6 +7,7 @@ obj-$(CONFIG_PMBUS)		+= pmbus_core.o
>  obj-$(CONFIG_SENSORS_PMBUS)	+= pmbus.o
>  obj-$(CONFIG_SENSORS_ADM1275)	+= adm1275.o
>  obj-$(CONFIG_SENSORS_BEL_PFE)	+= bel-pfe.o
> +obj-$(CONFIG_SENSORS_DELTA)	+= delta.o
>  obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
>  obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
>  obj-$(CONFIG_SENSORS_IR35221)	+= ir35221.o
> diff --git a/drivers/hwmon/pmbus/delta.c b/drivers/hwmon/pmbus/delta.c
> new file mode 100644
> index 000000000000..22e08325194d
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/delta.c
> @@ -0,0 +1,153 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Driver for Delta modules, Q54SJ108A2 series 1/4 Brick DC/DC
> + * Regulated Power Module
> + *
> + * Copyright 2020 Delta LLC.
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of_device.h>
> +#include <linux/pmbus.h>
> +#include <linux/util_macros.h>
> +#include "pmbus.h"
> +
> +enum chips {
> +	Q54SJ108A2
> +};
> +
> +static int delta_write_word_data(struct i2c_client *client, int page, int reg,
> +			       u16 word)
> +{
> +	u8 value;
> +	u8 ret;
> +
> +	switch (reg) {
> +	case PMBUS_VOUT_OV_FAULT_RESPONSE:
> +	case PMBUS_IOUT_OC_FAULT_RESPONSE:
> +		value = 0;
> +		ret = pmbus_write_byte_data(client, page, PMBUS_WRITE_PROTECT, value);
> +		value = (u8)word;
> +		return pmbus_write_byte_data(client, page, reg, value);
> +	default:
> +		return -ENODATA;
> +	}
> +}

This function is pointless. Neither PMBUS_VOUT_OV_FAULT_RESPONSE nor
PMBUS_IOUT_OC_FAULT_RESPONSE is written by the PMBus core.
Also, even if it was used, the commands are byte commands,
and write_work_data would never be called to issue those commands.

Guenter

> +
> +static const struct pmbus_driver_info delta_info[] = {
> +	[Q54SJ108A2] = {
> +		.pages = 1,
> +		.write_word_data = delta_write_word_data,
> +
> +		/* Source : Delta Q54SJ108A2 */
> +		.format[PSC_TEMPERATURE] = linear,
> +		.format[PSC_VOLTAGE_IN] = linear,
> +		.format[PSC_CURRENT_OUT] = linear,
> +
> +		.func[0] = PMBUS_HAVE_VIN |
> +		PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
> +		PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> +		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
> +		PMBUS_HAVE_STATUS_INPUT,
> +	},
> +};
> +
> +static int delta_probe(struct i2c_client *client, const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
> +	struct pmbus_driver_info *info;
> +	enum chips chip_id;
> +	int ret;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_BYTE_DATA |
> +				     I2C_FUNC_SMBUS_WORD_DATA |
> +				     I2C_FUNC_SMBUS_BLOCK_DATA))
> +		return -ENODEV;
> +
> +	if (client->dev.of_node)
> +		chip_id = (enum chips)of_device_get_match_data(dev);
> +	else
> +		chip_id = id->driver_data;
> +
> +	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "Failed to read Manufacturer ID\n");
> +		return ret;
> +	}
> +	if (ret != 5 || strncmp(buf, "DELTA", 5)) {
> +		buf[ret] = '\0';
> +		dev_err(dev, "Unsupported Manufacturer ID '%s'\n", buf);
> +		return -ENODEV;
> +	}
> +
> +	/*
> +	 * The chips support reading PMBUS_MFR_MODEL.
> +	 */
> +	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to read Manufacturer Model\n");
> +		return ret;
> +	}
> +	if (ret != 14 || strncmp(buf, "Q54SJ108A2", 10)) {
> +		buf[ret] = '\0';
> +		dev_err(dev, "Unsupported Manufacturer Model '%s'\n", buf);
> +		return -ENODEV;
> +	}
> +
> +	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_REVISION, buf);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to read Manufacturer Revision\n");
> +		return ret;
> +	}
> +	if (ret != 4 || buf[0] != 'S') {
> +		buf[ret] = '\0';
> +		dev_err(dev, "Unsupported Manufacturer Revision '%s'\n", buf);
> +		return -ENODEV;
> +	}
> +
> +	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	memcpy(info, &delta_info[chip_id], sizeof(*info));
> +
> +	return pmbus_do_probe(client, id, info);
> +}
> +
> +static const struct i2c_device_id delta_id[] = {
> +	{ "Q54SJ108A2", Q54SJ108A2 },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, delta_id);
> +
> +static const struct of_device_id delta_of_match[] = {
> +	{ .compatible = "delta,Q54SJ108A2", .data = (void *)Q54SJ108A2 },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, delta_of_match);
> +
> +static struct i2c_driver delta_driver = {
> +	.driver = {
> +		.name = "Q54SJ108A2",
> +		.of_match_table = delta_of_match,
> +	},
> +	.probe = delta_probe,
> +	.remove = pmbus_do_remove,
> +	.id_table = delta_id,
> +};
> +
> +module_i2c_driver(delta_driver);
> +
> +MODULE_AUTHOR("Delta <xiao.mx.ma@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("PMBus driver for Delta Q54SJ108A2 series modules");
> +MODULE_LICENSE("GPL");
> -- 
> 2.25.1
>