[v4, 2/6] pmbus: Add driver for Maxim MAX31785 Intelligent Fan Controller
Guenter Roeck
linux at roeck-us.net
Mon Nov 6 01:08:45 AEDT 2017
On Fri, Nov 03, 2017 at 03:53:02PM +1100, Andrew Jeffery wrote:
> The Maxim MAX31785 is a PMBus device providing closed-loop, multi-channel fan
> management with temperature and remote voltage sensing. Various fan control
> features are provided, including PWM frequency control, temperature hysteresis,
> dual tachometer measurements, and fan health monitoring.
>
I updated the above text a little to make it more obvious that "are provided"
refers to the chip, not (yet) to the driver.
> This patch presents a basic driver using only the existing features of the
> PMBus subsystem.
>
> Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
Applied to hwmon-next.
> ---
> Documentation/hwmon/max31785 | 51 ++++++++++++++++++
> drivers/hwmon/pmbus/Kconfig | 10 ++++
> drivers/hwmon/pmbus/Makefile | 1 +
> drivers/hwmon/pmbus/max31785.c | 116 +++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 178 insertions(+)
> create mode 100644 Documentation/hwmon/max31785
> create mode 100644 drivers/hwmon/pmbus/max31785.c
>
> diff --git a/Documentation/hwmon/max31785 b/Documentation/hwmon/max31785
> new file mode 100644
> index 000000000000..45fb6093dec2
> --- /dev/null
> +++ b/Documentation/hwmon/max31785
> @@ -0,0 +1,51 @@
> +Kernel driver max31785
> +======================
> +
> +Supported chips:
> + * Maxim MAX31785, MAX31785A
> + Prefix: 'max31785' or 'max31785a'
> + Addresses scanned: -
> + Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31785.pdf
> +
> +Author: Andrew Jeffery <andrew at aj.id.au>
> +
> +Description
> +-----------
> +
> +The Maxim MAX31785 is a PMBus device providing closed-loop, multi-channel fan
> +management with temperature and remote voltage sensing. Various fan control
> +features are provided, including PWM frequency control, temperature hysteresis,
> +dual tachometer measurements, and fan health monitoring.
> +
> +For dual rotor fan configuration, the MAX31785 exposes the slowest rotor of the
> +two in the fan[1-4]_input attributes.
> +
> +Usage Notes
> +-----------
> +
> +This driver does not probe for PMBus devices. You will have to instantiate
> +devices explicitly.
> +
> +Sysfs attributes
> +----------------
> +
> +fan[1-4]_alarm Fan alarm.
> +fan[1-4]_fault Fan fault.
> +fan[1-4]_input Fan RPM.
> +
> +in[1-6]_crit Critical maximum output voltage
> +in[1-6]_crit_alarm Output voltage critical high alarm
> +in[1-6]_input Measured output voltage
> +in[1-6]_label "vout[18-23]"
> +in[1-6]_lcrit Critical minimum output voltage
> +in[1-6]_lcrit_alarm Output voltage critical low alarm
> +in[1-6]_max Maximum output voltage
> +in[1-6]_max_alarm Output voltage high alarm
> +in[1-6]_min Minimum output voltage
> +in[1-6]_min_alarm Output voltage low alarm
> +
> +temp[1-11]_crit Critical high temperature
> +temp[1-11]_crit_alarm Chip temperature critical high alarm
> +temp[1-11]_input Measured temperature
> +temp[1-11]_max Maximum temperature
> +temp[1-11]_max_alarm Chip temperature high alarm
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 40019325b517..08479006c7f9 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -114,6 +114,16 @@ config SENSORS_MAX20751
> This driver can also be built as a module. If so, the module will
> be called max20751.
>
> +config SENSORS_MAX31785
> + tristate "Maxim MAX31785 and compatibles"
> + default n
> + help
> + If you say yes here you get hardware monitoring support for Maxim
> + MAX31785.
> +
> + This driver can also be built as a module. If so, the module will
> + be called max31785.
> +
> config SENSORS_MAX34440
> tristate "Maxim MAX34440 and compatibles"
> default n
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 459a6be3390e..a8bf0e490db9 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -12,6 +12,7 @@ obj-$(CONFIG_SENSORS_LTC2978) += ltc2978.o
> obj-$(CONFIG_SENSORS_LTC3815) += ltc3815.o
> obj-$(CONFIG_SENSORS_MAX16064) += max16064.o
> obj-$(CONFIG_SENSORS_MAX20751) += max20751.o
> +obj-$(CONFIG_SENSORS_MAX31785) += max31785.o
> obj-$(CONFIG_SENSORS_MAX34440) += max34440.o
> obj-$(CONFIG_SENSORS_MAX8688) += max8688.o
> obj-$(CONFIG_SENSORS_TPS40422) += tps40422.o
> diff --git a/drivers/hwmon/pmbus/max31785.c b/drivers/hwmon/pmbus/max31785.c
> new file mode 100644
> index 000000000000..9313849d5160
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/max31785.c
> @@ -0,0 +1,116 @@
> +/*
> + * Copyright (C) 2017 IBM Corp.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include "pmbus.h"
> +
> +enum max31785_regs {
> + MFR_REVISION = 0x9b,
> +};
> +
> +#define MAX31785_NR_PAGES 23
> +
> +#define MAX31785_FAN_FUNCS \
> + (PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12)
> +
> +#define MAX31785_TEMP_FUNCS \
> + (PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP)
> +
> +#define MAX31785_VOUT_FUNCS \
> + (PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT)
> +
> +static const struct pmbus_driver_info max31785_info = {
> + .pages = MAX31785_NR_PAGES,
> +
> + /* RPM */
> + .format[PSC_FAN] = direct,
> + .m[PSC_FAN] = 1,
> + .b[PSC_FAN] = 0,
> + .R[PSC_FAN] = 0,
> + .func[0] = MAX31785_FAN_FUNCS,
> + .func[1] = MAX31785_FAN_FUNCS,
> + .func[2] = MAX31785_FAN_FUNCS,
> + .func[3] = MAX31785_FAN_FUNCS,
> + .func[4] = MAX31785_FAN_FUNCS,
> + .func[5] = MAX31785_FAN_FUNCS,
> +
> + .format[PSC_TEMPERATURE] = direct,
> + .m[PSC_TEMPERATURE] = 1,
> + .b[PSC_TEMPERATURE] = 0,
> + .R[PSC_TEMPERATURE] = 2,
> + .func[6] = MAX31785_TEMP_FUNCS,
> + .func[7] = MAX31785_TEMP_FUNCS,
> + .func[8] = MAX31785_TEMP_FUNCS,
> + .func[9] = MAX31785_TEMP_FUNCS,
> + .func[10] = MAX31785_TEMP_FUNCS,
> + .func[11] = MAX31785_TEMP_FUNCS,
> + .func[12] = MAX31785_TEMP_FUNCS,
> + .func[13] = MAX31785_TEMP_FUNCS,
> + .func[14] = MAX31785_TEMP_FUNCS,
> + .func[15] = MAX31785_TEMP_FUNCS,
> + .func[16] = MAX31785_TEMP_FUNCS,
> +
> + .format[PSC_VOLTAGE_OUT] = direct,
> + .m[PSC_VOLTAGE_OUT] = 1,
> + .b[PSC_VOLTAGE_OUT] = 0,
> + .R[PSC_VOLTAGE_OUT] = 0,
> + .func[17] = MAX31785_VOUT_FUNCS,
> + .func[18] = MAX31785_VOUT_FUNCS,
> + .func[19] = MAX31785_VOUT_FUNCS,
> + .func[20] = MAX31785_VOUT_FUNCS,
> + .func[21] = MAX31785_VOUT_FUNCS,
> + .func[22] = MAX31785_VOUT_FUNCS,
> +};
> +
> +static int max31785_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = &client->dev;
> + struct pmbus_driver_info *info;
> + s64 ret;
> +
> + info = devm_kzalloc(dev, sizeof(struct pmbus_driver_info), GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> +
> + *info = max31785_info;
> +
> + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 255);
> + if (ret < 0)
> + return ret;
> +
> + return pmbus_do_probe(client, id, info);
> +}
> +
> +static const struct i2c_device_id max31785_id[] = {
> + { "max31785", 0 },
> + { "max31785a", 0 },
> + { },
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, max31785_id);
> +
> +static struct i2c_driver max31785_driver = {
> + .driver = {
> + .name = "max31785",
> + },
> + .probe = max31785_probe,
> + .remove = pmbus_do_remove,
> + .id_table = max31785_id,
> +};
> +
> +module_i2c_driver(max31785_driver);
> +
> +MODULE_AUTHOR("Andrew Jeffery <andrew at aj.id.au>");
> +MODULE_DESCRIPTION("PMBus driver for the Maxim MAX31785");
> +MODULE_LICENSE("GPL");
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