-----Original Message----- From: Guenter Roeck <groeck7@xxxxxxxxx> On Behalf Of Guenter Roeck Sent: Monday, March 18, 2024 5:07 PM To: Sabau, Radu bogdan <Radu.Sabau@xxxxxxxxxx>; Jean Delvare <jdelvare@xxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>; Conor Dooley <conor+dt@xxxxxxxxxx>; Jonathan Corbet <corbet@xxxxxxx>; Delphine CC Chiu <Delphine_CC_Chiu@xxxxxxxxxx>; linux-hwmon@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx; linux-i2c@xxxxxxxxxxxxxxx Subject: Re: [PATCH 2/2] hwmon: pmbus: adp1050 : Add driver support [External] On 3/18/24 04:21, Radu Sabau wrote: > Add support for ADP1050 Digital Controller for Isolated Power Supplies > with PMBus interface Voltage, Current and Temperature Monitor. > > The ADP1050 implements several features to enable a robust > system of parallel and redundant operation for customers who > require high availability. The device can measure voltage, > current and temperature that can be used in different > techniques to identify and safely shut down an erroneous > power supply in parallel operation mode. > > Signed-off-by: Radu Sabau <radu.sabau@xxxxxxxxxx> > --- > Documentation/hwmon/adp1050.rst | 69 ++++++++++++++++++++ > Documentation/hwmon/index.rst | 1 + > drivers/hwmon/pmbus/Kconfig | 10 +++ > drivers/hwmon/pmbus/Makefile | 1 + > drivers/hwmon/pmbus/adp1050.c | 111 ++++++++++++++++++++++++++++++++ > 5 files changed, 192 insertions(+) > create mode 100644 Documentation/hwmon/adp1050.rst > create mode 100644 drivers/hwmon/pmbus/adp1050.c > > diff --git a/Documentation/hwmon/adp1050.rst b/Documentation/hwmon/adp1050.rst > new file mode 100644 > index 000000000000..e3e5bb650a51 > --- /dev/null > +++ b/Documentation/hwmon/adp1050.rst > @@ -0,0 +1,69 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +Kernel driver adp1050 > +===================== > + > +Supported chips: > + > + * Analog Devices ADP1050 > + > + Prefix: 'adp1050' > + > + Addresses scanned: I2C 0x70 - 0x77 > + > + Datasheet: https://www.analog.com/media/en/technical-documentation/data- > +sheets/ADP1050.pdf > + > +Authors: > + > + - Radu Sabau <radu.sabau@xxxxxxxxxx> > + > + > +Description > +----------- > + > +This driver supprts hardware monitoring for Analog Devices ADP1050 Digital > +Controller for Isolated Power Supply with PMBus interface. > + > +The ADP1050 is an advanced digital controller with a PMBus™ > +interface targeting high density, high efficiency dc-to-dc power > +conversion used to monitor system temperatures, voltages and currents. > +Through the PMBus interface, the device can monitor input/output voltages, > +input current and temperature. > + > +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. > + > +The vin scale monitor value and iin scale monitor value can be > +configured by a device tree property;see > +Documentation/devicetree/bindings/hwmon/pmbus/adi,adp1050.yaml for details > + > +Platform data support > +--------------------- > + > +The driver supports standard PMBus driver platform data. > + > +Sysfs Attributes > +---------------- > + > +================= ======================================== > +in1_label "vin" > +in1_input Measured input voltage > +in1_alarm Input voltage alarm > +in2_label "vout1" > +in2_input Measured output voltage > +in2_crit Critical maximum output voltage > +in2_crit_alarm Output voltage high alarm > +in2_lcrit Critical minimum output voltage > +in2_lcrit_alarm Output voltage critical low alarm > +curr1_label "iin" > +curr1_input Measured input current. > +curr1_alarm Input current alarm > +temp1_input Measured temperature > +temp1_crit Critical high temperature > +temp1_crit_alarm Chip temperature critical high alarm > +================= ======================================== > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > index 1ca7a4fe1f8f..9a4fd576e6f6 100644 > --- a/Documentation/hwmon/index.rst > +++ b/Documentation/hwmon/index.rst > @@ -33,6 +33,7 @@ Hardware Monitoring Kernel Drivers > adm1266 > adm1275 > adm9240 > + adp1050 > ads7828 > adt7410 > adt7411 > diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig > index 557ae0c414b0..38e794d83cc3 100644 > --- a/drivers/hwmon/pmbus/Kconfig > +++ b/drivers/hwmon/pmbus/Kconfig > @@ -57,6 +57,16 @@ config SENSORS_ADM1275 > This driver can also be built as a module. If so, the module will > be called adm1275. > > +config SENSORS_ADP1050 > + tristate "Analog Devices ADP1050 digital controller for Power Supplies" > + help > + If you say yes here you get hardware monitoring support for Analog > + Devices ADP1050 digital controller for isolated power supply with > + PMBus interface. > + > + This driver can also be built as a module. If so, the module will > + be called adp1050. > + > config SENSORS_BEL_PFE > tristate "Bel PFE Compatible Power Supplies" > help > diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile > index f14ecf03ad77..95a8dea5e5ed 100644 > --- a/drivers/hwmon/pmbus/Makefile > +++ b/drivers/hwmon/pmbus/Makefile > @@ -8,6 +8,7 @@ obj-$(CONFIG_SENSORS_PMBUS) += pmbus.o > obj-$(CONFIG_SENSORS_ACBEL_FSG032) += acbel-fsg032.o > obj-$(CONFIG_SENSORS_ADM1266) += adm1266.o > obj-$(CONFIG_SENSORS_ADM1275) += adm1275.o > +obj-$(CONFIG_SENSORS_ADP1050) += adp1050.o > obj-$(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 > diff --git a/drivers/hwmon/pmbus/adp1050.c b/drivers/hwmon/pmbus/adp1050.c > new file mode 100644 > index 000000000000..53198d858156 > --- /dev/null > +++ b/drivers/hwmon/pmbus/adp1050.c > @@ -0,0 +1,111 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Hardware monitoring driver for Analog Devices ADP1050 > + * > + * Copyright (C) 2024 Analog Devices, Inc. > + */ > +#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/of.h> > +#include "pmbus.h" > + > +#define ADP1050_CHIP_PASSWORD 0xD7 > + > +#define ADP1050_VIN_SCALE_MONITOR 0xD8 > +#define ADP1050_IIN_SCALE_MONITOR 0xD9 > + > +static struct pmbus_driver_info adp1050_info = { > + .pages = 1, > + .format[PSC_VOLTAGE_IN] = linear, > + .format[PSC_VOLTAGE_OUT] = linear, > + .format[PSC_CURRENT_IN] = linear, > + .format[PSC_TEMPERATURE] = linear, > + .func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT > + | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT > + | PMBUS_HAVE_IIN | PMBUS_HAVE_TEMP > + | PMBUS_HAVE_STATUS_TEMP, > +}; > + > +static int adp1050_probe(struct i2c_client *client) > +{ > + u32 vin_scale_monitor, iin_scale_monitor; > + int ret; > + > + if (!i2c_check_functionality(client->adapter, > + I2C_FUNC_SMBUS_WRITE_WORD_DATA)) > + return -ENODEV; > + > + /* Unlock CHIP's password in order to be able to read/write to it's > + * VIN_SCALE and IIN_SCALE registers. > + */ > + ret = i2c_smbus_write_word_data(client, ADP1050_CHIP_PASSWORD, 0xFFFF); > + if (ret < 0) { > + dev_err_probe(&client->dev, "Device can't be unlocked.\n"); > + return ret; > + } > + > + ret = i2c_smbus_write_word_data(client, ADP1050_CHIP_PASSWORD, 0xFFFF); > + if (ret < 0) { > + dev_err_probe(&client->dev, "Device couldn't be unlocked.\n"); > + return ret; > + } > + The datasheet says that the factory default password is 0xffff. What if it isn't ? Refusing to instantiate the chip because it can't be unlocked seems a bit extreme. After all, the password _can_ be changed. This is indeed a bit extreme, will remove it. > + /* If adi,vin-scale-monitor isn't set or is set to 0 means that the > + * VIN monitor isn't used, therefore 0 is used as scale in order > + * for the readings to return 0. > + */ > + if (device_property_read_u32(&client->dev, "adi,vin-scale-monitor", > + &vin_scale_monitor)) > + vin_scale_monitor = 0; > + > + /* If adi,iin-scale-monitor isn't set or is set to 0 means that the > + * IIN monitor isn't used, therefore 0 is used as scale in order > + * for the readings to return 0. > + */ > + if (device_property_read_u32(&client->dev, "adi,iin-scale-monitor", > + &iin_scale_monitor)) > + iin_scale_monitor = 0; > + I don't think the "-monitor" extensions in those property names add any value. > + ret = i2c_smbus_write_word_data(client, ADP1050_VIN_SCALE_MONITOR, > + vin_scale_monitor); > + if (ret < 0) > + return ret; > + > + ret = i2c_smbus_write_word_data(client, ADP1050_IIN_SCALE_MONITOR, > + iin_scale_monitor); > + if (ret < 0) > + return ret; > + If vin and iin monitoring is disabled on purpose, why still set PMBUS_HAVE_VIN and PMBUS_HAVE_IIN above ? Reporting input values as 0 if the values are explicitly not monitored does not make sense to me. I am puzzled about this to start with. Unless I am missing something, the data sheet has no indication that VIN monitoring and/or IIN monitoring is actually turned off if iin_scale/vin_scale are set to 0. Why support the option to disable them ? That doesn't make sense to me. Please explain how/when this makes sense. Please also explain why chip support is made to depend on devicetree support. Register values may have been be set by rommon/bios or (much more likely) by manufacturing, or users could just want to keep the chip default. Why force-override it or even force-disable it ? At first I made the chip support depend on devicetree support because iin_scale and vin_scale are values that should be calculated depending on external hardware components. I tested with with ADP1050DC1-EVALZ board and there is a resistor divider on the VF (VIN) pin. Although now that you said it, chip support shouldn't depend on devicetree support, I tested the driver in this way and works the same, in my case I have a resistor divider and have to modify the scale accordingly in order for correct readings, and from a user point of view I actually found this way more suitable. Thanks, Guenter Thanks, Radu
