Re: [PATCH v4 2/2] hwmon: (pmbus/isl68137): Add driver for Intersil ISL68137 PWM Controller

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

On Mon, Apr 15, 2019 at 01:41:22PM -0700, Patrick Venture wrote:
> From: Maxim Sloyko <maxims@google.com>
> 
> Intersil ISL68137 is a digital output 7-phase configurable PWM
> controller with an AVSBus interface.
> 
> Signed-off-by: Maxim Sloyko <maxims@google.com>
> Signed-off-by: Robert Lippert <rlippert@google.com>
> Signed-off-by: Patrick Venture <venture@google.com>

Couple of minor comments below. Please resend and don't forget to copy
linux-hwmon@vger.kernel.org (I keep wondering why this patch doesn't
show up in patchwork ...).

Thanks,
Guenter

> ---
> v4:
>  Use kstrtobool
>  Cleanup parens
>  Use rc instead of temporary int
>  Delete unnecessary coment
>  Add remove to driver structure
> v3:
>  Added missing driver documentation
>  Cleaned up goto statements.
>  Add missing error check on pmbus_read_word_data
>  Transitioned to use SENSOR_DEVICE_ATTR_RW
>  Renamed enabled attribute to enable
>  Set up an attribute_group for the enable attribute and added to pmbus_info
>  Removed the boilerplate driver remove method
> v2:
>  Fixed bad header ordering.
> v1:
>  Original new patchset with fixes from Rob Lippert.
> ---
>  Documentation/hwmon/isl68137   |  72 ++++++++++++++
>  drivers/hwmon/pmbus/Kconfig    |   9 ++
>  drivers/hwmon/pmbus/Makefile   |   1 +
>  drivers/hwmon/pmbus/isl68137.c | 172 +++++++++++++++++++++++++++++++++
>  4 files changed, 254 insertions(+)
>  create mode 100644 Documentation/hwmon/isl68137
>  create mode 100644 drivers/hwmon/pmbus/isl68137.c
> 
> diff --git a/Documentation/hwmon/isl68137 b/Documentation/hwmon/isl68137
> new file mode 100644
> index 0000000000000..92e5c5fc5b777
> --- /dev/null
> +++ b/Documentation/hwmon/isl68137
> @@ -0,0 +1,72 @@
> +Kernel driver isl68137
> +======================
> +
> +Supported chips:
> +  * Intersil ISL68137
> +    Prefix: 'isl68137'
> +    Addresses scanned: -
> +    Datasheet: Publicly available at the Intersil website
> +      https://www.intersil.com/content/dam/Intersil/documents/isl6/isl68137.pdf
> +
> +Authors:
> +        Maxim Sloyko <maxims@google.com>
> +        Robert Lippert <rlippert@google.com>
> +        Patrick Venture <venture@google.com>
> +
> +Description
> +-----------
> +
> +Intersil ISL68137 is a digital output 7-phase configurable PWM
> +controller with an AVSBus interface.
> +
> +Usage Notes
> +-----------
> +
> +This driver does not probe for PMBus devices. You will have to instantiate
> +devices explicitly.
> +
> +The ISL68137 AVS operation mode must be enabled/disabled at runtime.
> +
> +Beyond the normal sysfs pmbus attributes, the driver exposes a control attribute.
> +
> +Additional Sysfs attributes
> +---------------------------
> +
> +avs(0|1)_enable		Controls the AVS state of each rail.
> +
> +curr1_label		"iin"
> +curr1_input		Measured input current
> +curr1_crit		Critical maximum current
> +curr1_crit_alarm	Current critical high alarm
> +
> +curr[2-3]_label		"iout[1-2]"
> +curr[2-3]_input		Measured output current
> +curr[2-3]_crit		Critical maximum current
> +curr[2-3]_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
> +
> +in[2-3]_label		"vout[1-2]"
> +in[2-3]_input		Measured output voltage
> +in[2-3]_lcrit		Critical minimum output voltage
> +in[2-3]_lcrit_alarm	Output voltage critical low alarm
> +in[2-3]_crit		Critical maximum output voltage
> +in[2-3]_crit_alarm	Output voltage critical high alarm
> +
> +power1_label		"pin"
> +power1_input		Measured input power
> +power1_alarm		Input power high alarm
> +
> +power[2-3]_label	"pout[1-2]"
> +power[2-3]_input	Measured output power
> +
> +temp[1-3]_input		Measured temperature
> +temp[1-3]_crit		Critical high temperature
> +temp[1-3]_crit_alarm	Chip temperature critical high alarm
> +temp[1-3]_max		Maximum temperature
> +temp[1-3]_max_alarm	Chip temperature high alarm
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index de87abab990e5..7edab7e30eaf9 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -63,6 +63,15 @@ config SENSORS_IR38064
>  	  This driver can also be built as a module. If so, the module will
>  	  be called ir38064.
>  
> +config SENSORS_ISL68137
> +	tristate "Intersil ISL68137"
> +	help
> +	  If you say yes here you get hardware monitoring support for Intersil
> +	  ISL68137.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called isl68137.
> +
>  config SENSORS_LM25066
>  	tristate "National Semiconductor LM25066 and compatibles"
>  	help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 7d1fa6b3c8c93..2219b93003167 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_SENSORS_ADM1275)	+= adm1275.o
>  obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
>  obj-$(CONFIG_SENSORS_IR35221)	+= ir35221.o
>  obj-$(CONFIG_SENSORS_IR38064)	+= ir38064.o
> +obj-$(CONFIG_SENSORS_ISL68137)	+= isl68137.o
>  obj-$(CONFIG_SENSORS_LM25066)	+= lm25066.o
>  obj-$(CONFIG_SENSORS_LTC2978)	+= ltc2978.o
>  obj-$(CONFIG_SENSORS_LTC3815)	+= ltc3815.o
> diff --git a/drivers/hwmon/pmbus/isl68137.c b/drivers/hwmon/pmbus/isl68137.c
> new file mode 100644
> index 0000000000000..4140c52d6f124
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/isl68137.c
> @@ -0,0 +1,172 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Hardware monitoring driver for Intersil ISL68137
> + *
> + * Copyright (c) 2017 Google Inc
> + *
> + */
> +
> +#include <linux/err.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include "pmbus.h"
> +
> +#define ISL68137_VOUT_AVS	0x30
> +
> +static ssize_t isl68137_avs_enable_show_page(struct i2c_client *client,
> +					     int page,
> +					     char *buf)
> +{
> +	int val = pmbus_read_byte_data(client, page, PMBUS_OPERATION);
> +
> +	return sprintf(buf, "%d\n",
> +		       (val & ISL68137_VOUT_AVS) == ISL68137_VOUT_AVS ? 1 : 0);
> +}
> +
> +static ssize_t isl68137_avs_enable_store_page(struct i2c_client *client,
> +					      int page,
> +					      const char *buf, size_t count)
> +{
> +	int rc, op_val;
> +	bool result;
> +
> +	if (count < 1)
> +		return -EINVAL;
> +

kstrtobool() takes care of that.

> +	rc = kstrtobool(buf, &result);
> +	if (!rc)
> +		return -EINVAL;
> +
> +	op_val = (result) ? ISL68137_VOUT_AVS : 0;

() is really quite unnecessary here.

> +
> +	/*
> +	 * Writes to VOUT setpoint over AVSBus will persist after the VRM is
> +	 * switched to PMBus control. Switching back to AVSBus control
> +	 * restores this persisted setpoint rather than re-initializing to
> +	 * PMBus VOUT_COMMAND. Writing VOUT_COMMAND first over PMBus before
> +	 * enabling AVS control is the workaround.
> +	 */
> +	if (op_val == ISL68137_VOUT_AVS) {
> +		rc = pmbus_read_word_data(client, page, PMBUS_VOUT_COMMAND);
> +		if (rc < 0)
> +			return rc;
> +
> +		rc = pmbus_write_word_data(client, page, PMBUS_VOUT_COMMAND,
> +					   rc);
> +		if (rc < 0)
> +			return rc;
> +	}
> +
> +	rc = pmbus_update_byte_data(client, page, PMBUS_OPERATION,
> +				    ISL68137_VOUT_AVS, op_val);
> +
> +	return (rc < 0) ? rc : count;
> +}
> +
> +static ssize_t isl68137_avs_enable_show(struct device *dev,
> +					struct device_attribute *devattr,
> +					char *buf)
> +{
> +	struct i2c_client *client = to_i2c_client(dev->parent);
> +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> +
> +	return isl68137_avs_enable_show_page(client, attr->index, buf);
> +}
> +
> +static ssize_t isl68137_avs_enable_store(struct device *dev,
> +				struct device_attribute *devattr,
> +				const char *buf, size_t count)
> +{
> +	struct i2c_client *client = to_i2c_client(dev->parent);
> +	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> +
> +	return isl68137_avs_enable_store_page(client, attr->index, buf, count);
> +}
> +
> +static SENSOR_DEVICE_ATTR_RW(avs0_enable, isl68137_avs_enable, 0);
> +static SENSOR_DEVICE_ATTR_RW(avs1_enable, isl68137_avs_enable, 1);
> +
> +static struct attribute *enable_attrs[] = {
> +	&sensor_dev_attr_avs0_enable.dev_attr.attr,
> +	&sensor_dev_attr_avs1_enable.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group enable_group = {
> +	.attrs = enable_attrs,
> +};
> +
> +static const struct attribute_group *attribute_groups[] = {
> +	&enable_group,
> +	NULL,
> +};
> +
> +static struct pmbus_driver_info isl68137_info = {
> +	.pages = 2,
> +	.format[PSC_VOLTAGE_IN] = direct,
> +	.format[PSC_VOLTAGE_OUT] = direct,
> +	.format[PSC_CURRENT_IN] = direct,
> +	.format[PSC_CURRENT_OUT] = direct,
> +	.format[PSC_POWER] = direct,
> +	.format[PSC_TEMPERATURE] = direct,
> +	.m[PSC_VOLTAGE_IN] = 1,
> +	.b[PSC_VOLTAGE_IN] = 0,
> +	.R[PSC_VOLTAGE_IN] = 3,
> +	.m[PSC_VOLTAGE_OUT] = 1,
> +	.b[PSC_VOLTAGE_OUT] = 0,
> +	.R[PSC_VOLTAGE_OUT] = 3,
> +	.m[PSC_CURRENT_IN] = 1,
> +	.b[PSC_CURRENT_IN] = 0,
> +	.R[PSC_CURRENT_IN] = 2,
> +	.m[PSC_CURRENT_OUT] = 1,
> +	.b[PSC_CURRENT_OUT] = 0,
> +	.R[PSC_CURRENT_OUT] = 1,
> +	.m[PSC_POWER] = 1,
> +	.b[PSC_POWER] = 0,
> +	.R[PSC_POWER] = 0,
> +	.m[PSC_TEMPERATURE] = 1,
> +	.b[PSC_TEMPERATURE] = 0,
> +	.R[PSC_TEMPERATURE] = 0,
> +	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN
> +	    | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
> +	    | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_TEMP
> +	    | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
> +	    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT,
> +	.func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
> +	    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT,
> +	.groups = attribute_groups,
> +};
> +
> +static int isl68137_probe(struct i2c_client *client,
> +			  const struct i2c_device_id *id)
> +{
> +	return pmbus_do_probe(client, id, &isl68137_info);
> +}
> +
> +static const struct i2c_device_id isl68137_id[] = {
> +	{"isl68137", 0},
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, isl68137_id);
> +
> +/* This is the driver that will be inserted */
> +static struct i2c_driver isl68137_driver = {
> +	.driver = {
> +		   .name = "isl68137",
> +		   },
> +	.probe = isl68137_probe,
> +	.remove = pmbus_do_remove,
> +	.id_table = isl68137_id,
> +};
> +
> +module_i2c_driver(isl68137_driver);
> +
> +MODULE_AUTHOR("Maxim Sloyko <maxims@google.com>");
> +MODULE_DESCRIPTION("PMBus driver for Intersil ISL68137");
> +MODULE_LICENSE("GPL");
> -- 
> 2.21.0.392.gf8f6787159e-goog
>