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From: Michael Walle <michael@walle.cc>
To: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org,
	linux-pwm@vger.kernel.org, linux-watchdog@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: "Linus Walleij" <linus.walleij@linaro.org>,
	"Bartosz Golaszewski" <bgolaszewski@baylibre.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Jean Delvare" <jdelvare@suse.com>,
	"Guenter Roeck" <linux@roeck-us.net>,
	"Lee Jones" <lee.jones@linaro.org>,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Wim Van Sebroeck" <wim@linux-watchdog.org>,
	"Shawn Guo" <shawnguo@kernel.org>, "Li Yang" <leoyang.li@nxp.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Jason Cooper" <jason@lakedaemon.net>,
	"Marc Zyngier" <maz@kernel.org>,
	"Mark Brown" <broonie@kernel.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
	"Michael Walle" <michael@walle.cc>
Subject: [PATCH v5 09/13] hwmon: add support for the sl28cpld hardware monitoring controller
Date: Mon,  6 Jul 2020 19:53:49 +0200
Message-ID: <20200706175353.16404-10-michael@walle.cc> (raw)
In-Reply-To: <20200706175353.16404-1-michael@walle.cc>

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@walle.cc>
Acked-by: Guenter Roeck <linux@roeck-us.net>
---
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 55ff4b7c5349..1f4beb7449c7 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -153,6 +153,7 @@ 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@walle.cc>
+
+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 288ae9f63588..af2823f09bd1 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1459,6 +1459,16 @@ 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"
+	select MFD_SIMPLE_MFD_I2C
+	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 3e32c21f5efe..03822f6bf970 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -158,6 +158,7 @@ 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@walle.cc>");
+MODULE_LICENSE("GPL");
-- 
2.20.1

  parent reply index

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-06 17:53 [PATCH v5 00/13] Add support for Kontron sl28cpld Michael Walle
2020-07-06 17:53 ` [PATCH v5 01/13] regmap-irq: use fwnode instead of device node in add_irq_chip() Michael Walle
2020-07-08 10:22   ` Mark Brown
     [not found] ` <20200706175353.16404-1-michael-QKn5cuLxLXY@public.gmane.org>
2020-07-06 17:53   ` [PATCH v5 02/13] mfd: add simple regmap based I2C driver Michael Walle
     [not found]     ` <20200706175353.16404-3-michael-QKn5cuLxLXY@public.gmane.org>
2020-07-17  9:04       ` Lee Jones
2020-07-19 22:25         ` Michael Walle
2020-07-17  9:06     ` Lee Jones
2020-07-19 22:31       ` Michael Walle
2020-07-20  7:43         ` Lee Jones
2020-07-06 17:53   ` [PATCH v5 06/13] watchdog: add support for sl28cpld watchdog Michael Walle
2020-07-06 17:53   ` [PATCH v5 12/13] arm64: dts: freescale: sl28: enable LED support Michael Walle
2020-07-17  8:36     ` Pavel Machek
2020-07-17 21:54       ` Michael Walle
2020-07-06 17:53 ` [PATCH v5 03/13] dt-bindings: mfd: Add bindings for sl28cpld Michael Walle
2020-07-13 16:04   ` Rob Herring
2020-07-06 17:53 ` [PATCH v5 04/13] mfd: simple-mfd-i2c: add sl28cpld support Michael Walle
2020-07-06 17:53 ` [PATCH v5 05/13] irqchip: add sl28cpld interrupt controller support Michael Walle
2020-07-08  9:37   ` Marc Zyngier
2020-07-06 17:53 ` [PATCH v5 07/13] pwm: add support for sl28cpld PWM controller Michael Walle
2020-07-09  8:50   ` Uwe Kleine-König
     [not found]     ` <20200709085006.b54ype3p4yu64upl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2020-07-11 17:28       ` Michael Walle
2020-07-13  8:47         ` Uwe Kleine-König
2020-07-14 11:31           ` Michael Walle
2020-07-14 16:08             ` Uwe Kleine-König
2020-07-14 21:09               ` Michael Walle
2020-07-15 16:36                 ` Uwe Kleine-König
2020-07-15 17:45                   ` Michael Walle
2020-07-15 18:18                     ` Uwe Kleine-König
2020-07-15 20:41                       ` Michael Walle
2020-07-16  6:10                         ` Uwe Kleine-König
2020-07-06 17:53 ` [PATCH v5 08/13] gpio: add support for the sl28cpld GPIO controller Michael Walle
     [not found]   ` <20200706175353.16404-9-michael-QKn5cuLxLXY@public.gmane.org>
2020-07-08  7:35     ` Linus Walleij
2020-07-17  0:25   ` kernel test robot
2020-07-06 17:53 ` Michael Walle [this message]
2020-07-06 17:53 ` [PATCH v5 10/13] arm64: dts: freescale: sl28: enable sl28cpld Michael Walle
2020-07-06 17:53 ` [PATCH v5 11/13] arm64: dts: freescale: sl28: map GPIOs to input events Michael Walle
2020-07-06 17:53 ` [PATCH v5 13/13] arm64: dts: freescale: sl28: enable fan support Michael Walle
     [not found]   ` <20200706175353.16404-14-michael-QKn5cuLxLXY@public.gmane.org>
2020-07-08  7:39     ` Linus Walleij
     [not found]       ` <CACRpkdaPO7CGNrxmjL5QH1cxP5wqku1oMtQaQgJfeKiKqiGAOg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2020-07-08  7:56         ` Michael Walle

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