Add support for the hardware monitoring controller of the sl28cpld board management controller. This driver is part of a multi-function device. Signed-off-by: Michael Walle <michael@xxxxxxxx> Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- Changes since v7: - added "depends on MFD_SL28CPLD || COMPILE_TEST" Changes since v6: - none Changes since v5: - none Changes since v4: - update copyright year - remove #include <linux/of_device.h>, suggested by Andy. - use PTR_ERR_OR_ZERO(), suggested by Andy. - remove the platform device table - don't use KBUID_MODNAME Changes since v3: - see cover letter Documentation/hwmon/index.rst | 1 + Documentation/hwmon/sl28cpld.rst | 36 ++++++++ drivers/hwmon/Kconfig | 10 +++ drivers/hwmon/Makefile | 1 + drivers/hwmon/sl28cpld-hwmon.c | 142 +++++++++++++++++++++++++++++++ 5 files changed, 190 insertions(+) create mode 100644 Documentation/hwmon/sl28cpld.rst create mode 100644 drivers/hwmon/sl28cpld-hwmon.c diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index 750d3a975d82..d90c43c82936 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -154,6 +154,7 @@ Hardware Monitoring Kernel Drivers sht3x shtc1 sis5595 + sl28cpld smm665 smsc47b397 smsc47m192 diff --git a/Documentation/hwmon/sl28cpld.rst b/Documentation/hwmon/sl28cpld.rst new file mode 100644 index 000000000000..7ed65f78250c --- /dev/null +++ b/Documentation/hwmon/sl28cpld.rst @@ -0,0 +1,36 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +Kernel driver sl28cpld +====================== + +Supported chips: + + * Kontron sl28cpld + + Prefix: 'sl28cpld' + + Datasheet: not available + +Authors: Michael Walle <michael@xxxxxxxx> + +Description +----------- + +The sl28cpld is a board management controller which also exposes a hardware +monitoring controller. At the moment this controller supports a single fan +supervisor. In the future there might be other flavours and additional +hardware monitoring might be supported. + +The fan supervisor has a 7 bit counter register and a counter period of 1 +second. If the 7 bit counter overflows, the supervisor will automatically +switch to x8 mode to support a wider input range at the loss of +granularity. + +Sysfs entries +------------- + +The following attributes are supported. + +======================= ======================================================== +fan1_input Fan RPM. Assuming 2 pulses per revolution. +======================= ======================================================== diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 8dc28b26916e..d98c0a6860d1 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1479,6 +1479,16 @@ config SENSORS_RASPBERRYPI_HWMON This driver can also be built as a module. If so, the module will be called raspberrypi-hwmon. +config SENSORS_SL28CPLD + tristate "Kontron sl28cpld hardware monitoring driver" + depends on MFD_SL28CPLD || COMPILE_TEST + help + If you say yes here you get support for the fan supervisor of the + sl28cpld board management controller. + + This driver can also be built as a module. If so, the module + will be called sl28cpld-hwmon. + config SENSORS_SHT15 tristate "Sensiron humidity and temperature sensors. SHT15 and compat." depends on GPIOLIB || COMPILE_TEST diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index a8f4b35b136b..dee8511f9348 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -159,6 +159,7 @@ obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o +obj-$(CONFIG_SENSORS_SL28CPLD) += sl28cpld-hwmon.o obj-$(CONFIG_SENSORS_SHT15) += sht15.o obj-$(CONFIG_SENSORS_SHT21) += sht21.o obj-$(CONFIG_SENSORS_SHT3x) += sht3x.o diff --git a/drivers/hwmon/sl28cpld-hwmon.c b/drivers/hwmon/sl28cpld-hwmon.c new file mode 100644 index 000000000000..e48f58ec5b9c --- /dev/null +++ b/drivers/hwmon/sl28cpld-hwmon.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * sl28cpld hardware monitoring driver + * + * Copyright 2020 Kontron Europe GmbH + */ + +#include <linux/bitfield.h> +#include <linux/hwmon.h> +#include <linux/kernel.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/regmap.h> + +#define FAN_INPUT 0x00 +#define FAN_SCALE_X8 BIT(7) +#define FAN_VALUE_MASK GENMASK(6, 0) + +struct sl28cpld_hwmon { + struct regmap *regmap; + u32 offset; +}; + +static umode_t sl28cpld_hwmon_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + return 0444; +} + +static int sl28cpld_hwmon_read(struct device *dev, + enum hwmon_sensor_types type, u32 attr, + int channel, long *input) +{ + struct sl28cpld_hwmon *hwmon = dev_get_drvdata(dev); + unsigned int value; + int ret; + + switch (attr) { + case hwmon_fan_input: + ret = regmap_read(hwmon->regmap, hwmon->offset + FAN_INPUT, + &value); + if (ret) + return ret; + /* + * The register has a 7 bit value and 1 bit which indicates the + * scale. If the MSB is set, then the lower 7 bit has to be + * multiplied by 8, to get the correct reading. + */ + if (value & FAN_SCALE_X8) + value = FIELD_GET(FAN_VALUE_MASK, value) << 3; + + /* + * The counter period is 1000ms and the sysfs specification + * says we should asssume 2 pulses per revolution. + */ + value *= 60 / 2; + + break; + default: + return -EOPNOTSUPP; + } + + *input = value; + return 0; +} + +static const u32 sl28cpld_hwmon_fan_config[] = { + HWMON_F_INPUT, + 0 +}; + +static const struct hwmon_channel_info sl28cpld_hwmon_fan = { + .type = hwmon_fan, + .config = sl28cpld_hwmon_fan_config, +}; + +static const struct hwmon_channel_info *sl28cpld_hwmon_info[] = { + &sl28cpld_hwmon_fan, + NULL +}; + +static const struct hwmon_ops sl28cpld_hwmon_ops = { + .is_visible = sl28cpld_hwmon_is_visible, + .read = sl28cpld_hwmon_read, +}; + +static const struct hwmon_chip_info sl28cpld_hwmon_chip_info = { + .ops = &sl28cpld_hwmon_ops, + .info = sl28cpld_hwmon_info, +}; + +static int sl28cpld_hwmon_probe(struct platform_device *pdev) +{ + struct sl28cpld_hwmon *hwmon; + struct device *hwmon_dev; + int ret; + + if (!pdev->dev.parent) + return -ENODEV; + + hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL); + if (!hwmon) + return -ENOMEM; + + hwmon->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!hwmon->regmap) + return -ENODEV; + + ret = device_property_read_u32(&pdev->dev, "reg", &hwmon->offset); + if (ret) + return -EINVAL; + + hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, + "sl28cpld_hwmon", hwmon, + &sl28cpld_hwmon_chip_info, NULL); + if (IS_ERR(hwmon_dev)) + dev_err(&pdev->dev, "failed to register as hwmon device"); + + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct of_device_id sl28cpld_hwmon_of_match[] = { + { .compatible = "kontron,sl28cpld-fan" }, + {} +}; +MODULE_DEVICE_TABLE(of, sl28cpld_hwmon_of_match); + +static struct platform_driver sl28cpld_hwmon_driver = { + .probe = sl28cpld_hwmon_probe, + .driver = { + .name = "sl28cpld-fan", + .of_match_table = sl28cpld_hwmon_of_match, + }, +}; +module_platform_driver(sl28cpld_hwmon_driver); + +MODULE_DESCRIPTION("sl28cpld Hardware Monitoring Driver"); +MODULE_AUTHOR("Michael Walle <michael@xxxxxxxx>"); +MODULE_LICENSE("GPL"); -- 2.20.1