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ARM: mvebu: Add driver for the Zyxel NSA3XX hwmon MCU

PATCH Superseded Adam Baker 4 participants 8 messages Feb 10, 2016 – Feb 15, 2016

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Adam Baker

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#0 lore raw

cover ARM: mvebu: Add driver for the Zyxel NSA3XX hwmon MCU

This patch series adds a driver to support the hardware monitoring MCU that is present in some models of the Zyxel NSA3xx series of NAS units.

A patch is included to add it to the device tree for the NSA320 model, patches to the other device trees will be included if testers come forward (I already have a possible tester for NSA325).

There are no dependencies between the patches so I guess the first two should go via the hardware monitoring maintainers and the third via the ARM mvebu maintainers.

[PATCH 1/3] Define a binding for the hardware monitoring chip present [PATCH 2/3] Create a driver to support the hardware monitoring chip [PATCH 3/3] Add an entry for the hardware monitoring MCU

 Documentation/devicetree/bindings/hwmon/nsa320-mcu.txt |  21 ++++++++
 arch/arm/boot/dts/kirkwood-nsa320.dts                  |  13 ++++-
 drivers/hwmon/Kconfig                                  |  13 +++++
 drivers/hwmon/Makefile                                 |   1 +
 drivers/hwmon/nsa3xx-hwmon.c                           | 223 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 269 insertions(+), 2 deletions(-)
author
#1 lore raw

PATCH 1/3 ARM: mvebu: Define binding for the nsa3xx-hwmon driver

Define a binding for the hardware monitoring chip present in several variants of the Zyxel NSA3xx NAS devices.

---
 .../devicetree/bindings/hwmon/nsa320-mcu.txt        | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/nsa320-mcu.txt
Documentation/devicetree/bindings/hwmon/nsa320-mcu.txt new file +21 -0
new file mode 100644
index 0000000..7b346d4
@@ -0,0 +1,21 @@
+Bindings for the fan / temperature monitor microcontroller used on
+the Zyxel NSA 320 and several subsequent models.
+
+Required properties:
+- compatible	: "zyxel,nsa320-mcu"
+- data-gpios	: The GPIO pin connected to the data line on the MCU
+- clk-gpios	: The GPIO pin connected to the clock line on the MCU
+- act-gpios	: The GPIO pin connected to the active line on the MCU
+
+Example:
+
+	hwmon {
+		compatible = "zyxel,nsa320-mcu";
+		pinctrl-0 = <&pmx_mcu_data &pmx_mcu_clk &pmx_mcu_act>;
+		pinctrl-names = "default";
+
+		data-gpios = <&gpio0 14 GPIO_ACTIVE_HIGH>;
+		clk-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+		act-gpios = <&gpio0 17 GPIO_ACTIVE_LOW>;
+	};
+
Signature · 1 line
2.1.4
maintainer
#2 lore raw

PATCH 1/3 ARM: mvebu: Define binding for the nsa3xx-hwmon driver

Quoted 8 lines · Adam Baker

Define a binding for the hardware monitoring chip present in several variants of the Zyxel NSA3xx NAS devices.

---
 .../devicetree/bindings/hwmon/nsa320-mcu.txt        | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/nsa320-mcu.txt
author
#3 lore raw

PATCH 2/3 ARM: mvebu: Create a NSA3xx hardware monitoring driver

In reply to Adam Baker

Create a driver to support the hardware monitoring chip present in several models of Zyxel NSA3xx NAS devices.

The driver reads fan speed and temperature from a suitably programmed MCU on the device.

---
I've tested this on an NSA-320, I've had someone offer to test it on NSA-325 so hopefully I will get a tested by back.

---
 drivers/hwmon/Kconfig        |  13 +++
 drivers/hwmon/Makefile       |   1 +
 drivers/hwmon/nsa3xx-hwmon.c | 223 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 237 insertions(+)
 create mode 100644 drivers/hwmon/nsa3xx-hwmon.c
drivers/hwmon/Kconfig +13 -0
index 80a73bf..8801b78 100644
@@ -1757,6 +1757,19 @@ config SENSORS_ULTRA45
 	  This driver provides support for the Ultra45 workstation environmental
 	  sensors.
 
+config SENSORS_NSA3XX
+	tristate "ZyXEL NSA3xx fan speed and temperature sensors"
+	depends on GPIOLIB && OF
+	help
+	  If you say yes here you get support for hardware monitoring
+	  for the ZyXEL NSA3XX Media Servers.
+
+	  The sensor data is taken from a Holtek HT46R065 microcontroller
+	  connected to GPIO lines.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called nsa3xx-hwmon.
+
 if ACPI
 
 comment "ACPI drivers"
drivers/hwmon/Makefile +1 -0
index 12a3239..e85414a 100644
@@ -118,6 +118,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
 obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
 obj-$(CONFIG_SENSORS_MAX31790)	+= max31790.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
+obj-$(CONFIG_SENSORS_NSA3XX)	+= nsa3xx-hwmon.o
 obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
 obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
 obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
drivers/hwmon/nsa3xx-hwmon.c new file +223 -0

223 lines not on this page · raw message

Signature · 1 line
2.1.4
maintainer
#4 lore raw

PATCH 2/3 ARM: mvebu: Create a NSA3xx hardware monitoring driver

Hi,

Quoted 7 lines · Adam Baker

Create a driver to support the hardware monitoring chip present in several models of Zyxel NSA3xx NAS devices.

The driver reads fan speed and temperature from a suitably programmed MCU on the device.

Please name the driver nsa320. It may ultimately support other devices, but that doesn't mean it is going to support NSA-35x or other future similar devices.

Got the headline, please use

hwmon: Add driver for Zyxel NSA-320

Quoted 15 lines

---
I've tested this on an NSA-320, I've had someone offer to test it on NSA-325 so hopefully I will get a tested by back.

---
 drivers/hwmon/Kconfig        |  13 +++
 drivers/hwmon/Makefile       |   1 +
 drivers/hwmon/nsa3xx-hwmon.c | 223 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 237 insertions(+)
 create mode 100644 drivers/hwmon/nsa3xx-hwmon.c
drivers/hwmon/Kconfig +0 -0
index 80a73bf..8801b78 100644

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1760

Quoted 4 lines
drivers/hwmon/Kconfig +1 -0
@@ -1757,6 +1757,19 @@ config SENSORS_ULTRA45
 	  This driver provides support for the Ultra45 workstation environmental
 	  sensors.
 
+config SENSORS_NSA3XX

Please try to stick with alphabetic order.

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1761

Quoted 1 line
drivers/hwmon/Kconfig +1 -0
+	tristate "ZyXEL NSA3xx fan speed and temperature sensors"

... NSA-320 and compatible ...

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1762

Quoted 1 line
drivers/hwmon/Kconfig +1 -0
+	depends on GPIOLIB && OF

Can you add some additional dependencies ?

It is quite unlikely that the driver is needed on an X86. Please use at least

	depends on ARM || COMPILE_TEST

or a more specific dependency if the SoC is known. MACH_KIRKWOOD, maybe ?

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1765

Quoted 3 lines
drivers/hwmon/Kconfig +3 -0
+	help
+	  If you say yes here you get support for hardware monitoring
+	  for the ZyXEL NSA3XX Media Servers.

Please be specific which devices are supported. Feel free to add "and compatibles", but please no generic and misleading statements such as 3XX.

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1769

Quoted 4 lines
drivers/hwmon/Kconfig +4 -0
+
+	  The sensor data is taken from a Holtek HT46R065 microcontroller
+	  connected to GPIO lines.
+

Is that relevant ?

Quoted 11 lines
drivers/hwmon/Kconfig +3 -0
+	  This driver can also be built as a module. If so, the module
+	  will be called nsa3xx-hwmon.
+
 if ACPI
 
 comment "ACPI drivers"
drivers/hwmon/Makefile +0 -0
index 12a3239..e85414a 100644

drivers/hwmon/Makefile obj-$(CONFIG_SENSORS_MAX6650) += max6650.o · line 121

Quoted 4 lines
drivers/hwmon/Makefile +1 -0
@@ -118,6 +118,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
 obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
 obj-$(CONFIG_SENSORS_MAX31790)	+= max31790.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
+obj-$(CONFIG_SENSORS_NSA3XX)	+= nsa3xx-hwmon.o

Please try to stick with alphabetic order.

drivers/hwmon/nsa3xx-hwmon.c

Quoted 8 lines
drivers/hwmon/Makefile +0 -0
 obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
 obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
 obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
drivers/hwmon/nsa3xx-hwmon.c new file +0 -0
new file mode 100644
index 0000000..0fbf118

nsa320-hwmon.c

drivers/hwmon/nsa3xx-hwmon.c line 4

Quoted 5 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
@@ -0,0 +1,223 @@
+/*
+ * drivers/hwmon/nsa3xx-hwmon.c
+ *
+ * ZyXEL NSA3xx Media Servers

Please be specific.

Quoted 19 lines
drivers/hwmon/nsa3xx-hwmon.c new file +19 -0
+ * hardware monitoring
+ *
+ * Copyright (C) 2016 Adam Baker <[email protected]>
+ * based on a board file driver
+ * Copyright (C) 2012 Peter Schildmann <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License v2 as published by the
+ * Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>

drivers/hwmon/nsa3xx-hwmon.c line 33

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+

Please order include files alphabetically.

drivers/hwmon/nsa3xx-hwmon.c line 46

Quoted 13 lines
drivers/hwmon/nsa3xx-hwmon.c new file +13 -0
+#define MAGIC_NUMBER 0x55
+
+/*
+ * The Zyxel hwmon MCU is a Holtek HT46R065 that is factory programmed
+ * to perform temperature and fan speed monitoring. It is read by taking
+ * the active pin low. The 32 bit output word is then clocked onto the
+ * data line. The MSB of the data word is a magic nuber to indicate it
+ * has been read correctly, the next byte is the fan speed (in hundreds
+ * of RPM) and the last two bytes are the temperature (in tenths of a
+ * degree)
+ */
+
+struct nsa3xx_hwmon {

s/nsa3xx/nsa320/g for the entire file, please.

drivers/hwmon/nsa3xx-hwmon.c line 50

Quoted 4 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
+	struct device		*classdev;
+	struct mutex		update_lock;	/* lock GPIO operations */
+	unsigned long		last_updated;	/* jiffies */
+	u32			mcu_data;

I would suggest to use unsigned long here. See below for reasons.

drivers/hwmon/nsa3xx-hwmon.c line 58

Quoted 8 lines
drivers/hwmon/nsa3xx-hwmon.c new file +8 -0
+	struct gpio_desc	*act;
+	struct gpio_desc	*clk;
+	struct gpio_desc	*data;
+};
+
+enum nsa3xx_inputs {
+	NSA3XX_FAN = 1,
+	NSA3XX_TEMP = 0,

Any special reason for the unusual order ? If yes, please explain.

Quoted 18 lines
drivers/hwmon/nsa3xx-hwmon.c new file +18 -0
+};
+
+static const char * const nsa3xx_input_names[] = {
+	[NSA3XX_FAN] = "Chassis Fan",
+	[NSA3XX_TEMP] = "System Temperature",
+};
+
+/* Although this protocol looks similar to SPI the long delay
+ * between the active (aka chip select) signal and the shorter
+ * delay between clock pulses are needed for reliable operation.
+ * The delays provided are taken from the manufacturer kernel,
+ * testing suggest they probably incorporate a reasonable safety
+ * margin. (The single device tested became unreliable if the
+ * delay was reduced to 1/10th of this value.)
+ */
+static unsigned long nsa3xx_hwmon_update(struct device *dev)
+{
+	u32 mcu_data;

drivers/hwmon/nsa3xx-hwmon.c line 86

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+	u32 mask;
+	struct nsa3xx_hwmon *hwmon = dev_get_drvdata(dev);
+
+	mutex_lock(&hwmon->update_lock);
+
+	mcu_data = hwmon->mcu_data;
+
+	if (time_after(jiffies, hwmon->last_updated + HZ) ||
+							mcu_data == 0) {
+

Please no blank line here. Also, please align continuation lines with '('. However, unless I am missing something, the continuation line is not needed in the first place. Please no unnecessary continuation lines.

drivers/hwmon/nsa3xx-hwmon.c line 90

Quoted 4 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
+		gpiod_set_value(hwmon->act, 1);
+		msleep(100);
+
+		for (mask = BIT(31); mask; mask >>= 1) {

Since you are using BIT(), please include linux/bitops.h.

Quoted 4 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
+			gpiod_set_value(hwmon->clk, 0);
+			usleep_range(100, 200);
+			gpiod_set_value(hwmon->clk, 1);
+			usleep_range(100, 200);

drivers/hwmon/nsa3xx-hwmon.c line 104

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+			if (gpiod_get_value(hwmon->data))
+				mcu_data |= mask;
+		}
+
+		gpiod_set_value(hwmon->act, 0);
+		dev_dbg(dev, "Read raw MCU data %08x\n", mcu_data);
+
+		if ((mcu_data >> 24) != MAGIC_NUMBER) {
+			dev_err(dev, "Read invalid MCU data %08x\n", mcu_data);
+			mcu_data = 0;

Instead of an error message, it would be better to return an error code (probably -EIO since we don't know better).

The calling code can then return the error to user space.

Quoted 16 lines
drivers/hwmon/nsa3xx-hwmon.c new file +16 -0
+		}
+
+		hwmon->mcu_data = mcu_data;
+		hwmon->last_updated = jiffies;
+	}
+
+	mutex_unlock(&hwmon->update_lock);
+
+	return mcu_data;
+}
+
+static ssize_t show_label(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	int channel = to_sensor_dev_attr(attr)->index;
+

drivers/hwmon/nsa3xx-hwmon.c line 130

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+	return sprintf(buf, "%s\n", nsa3xx_input_names[channel]);
+}
+
+static ssize_t show_value(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	int channel = to_sensor_dev_attr(attr)->index;
+	unsigned long mcu_data = nsa3xx_hwmon_update(dev);
+	unsigned long value = 0;
+

If nsa3xx_hwmon_update() returns an error code, you can use

	if (IS_ERR_VALUE(mcu_data))
		return (long)mcu_data;

or even better have nsa3xx_hwmon_update() return int directly to indicate an error.

drivers/hwmon/nsa3xx-hwmon.c line 131

Quoted 1 line
drivers/hwmon/nsa3xx-hwmon.c new file +1 -0
+	pr_debug("channel value 0x%02x!\n", channel);

Is this really useful ? I would suggest to drop debug messages unless really needed. If you really think the message is useful, please use dev_dbg().

Quoted 30 lines
drivers/hwmon/nsa3xx-hwmon.c new file +30 -0
+	switch (channel) {
+	case NSA3XX_TEMP:
+		value = (mcu_data & 0xffff) * 100;
+		break;
+	case NSA3XX_FAN:
+		value = ((mcu_data & 0xff0000) >> 16) * 100;
+		break;
+	}
+	return sprintf(buf, "%lu\n", value);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, NSA3XX_TEMP);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_value, NULL, NSA3XX_TEMP);
+static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, show_label, NULL, NSA3XX_FAN);
+static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_value, NULL, NSA3XX_FAN);
+
+static struct attribute *nsa3xx_attrs[] = {
+	&sensor_dev_attr_temp1_label.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_fan1_label.dev_attr.attr,
+	&sensor_dev_attr_fan1_input.dev_attr.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(nsa3xx);
+
+static const struct of_device_id of_nsa3xx_hwmon_match[] = {
+	{ .compatible = "zyxel,nsa320-mcu", },
+	{ },
+};

drivers/hwmon/nsa3xx-hwmon.c line 171

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+
+static int nsa3xx_hwmon_probe(struct platform_device *pdev)
+{
+	struct nsa3xx_hwmon *hwmon;
+
+	hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
+	if (!hwmon)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, hwmon);

Unnecessary.

drivers/hwmon/nsa3xx-hwmon.c line 183

Quoted 12 lines
drivers/hwmon/nsa3xx-hwmon.c new file +12 -0
+
+	/* Look up the GPIO pins to use */
+	hwmon->act = devm_gpiod_get(&pdev->dev, "act", GPIOD_OUT_LOW);
+	hwmon->clk = devm_gpiod_get(&pdev->dev, "clk", GPIOD_OUT_HIGH);
+	hwmon->data = devm_gpiod_get(&pdev->dev, "data", GPIOD_IN);
+
+	if (IS_ERR(hwmon->act))
+		return PTR_ERR(hwmon->act);
+	if (IS_ERR(hwmon->clk))
+		return PTR_ERR(hwmon->clk);
+	if (IS_ERR(hwmon->data))
+		return PTR_ERR(hwmon->data);

Please reorder to have the error checks immediately after the calls to devm_gpiod_get().

drivers/hwmon/nsa3xx-hwmon.c line 188

Quoted 5 lines
drivers/hwmon/nsa3xx-hwmon.c new file +5 -0
+
+	mutex_init(&hwmon->update_lock);
+
+	hwmon->classdev = devm_hwmon_device_register_with_groups(&pdev->dev,
+					"nsa3xx", hwmon, nsa3xx_groups);

classdev is only used in this function and thus does not have to be kept in struct nsa3xx_hwmon.

drivers/hwmon/nsa3xx-hwmon.c line 193

Quoted 5 lines
drivers/hwmon/nsa3xx-hwmon.c new file +5 -0
+	if (IS_ERR(hwmon->classdev))
+		return PTR_ERR(hwmon->classdev);
+
+	dev_dbg(&pdev->dev, "initialized\n");
+

This message is really unnecessary. Please just use

	return PTR_ERR_OR_ZERO(classdev);

drivers/hwmon/nsa3xx-hwmon.c line 204

Quoted 11 lines
drivers/hwmon/nsa3xx-hwmon.c new file +11 -0
+	return 0;
+}
+
+static int nsa3xx_hwmon_remove(struct platform_device *pdev)
+{
+	/* All resources are allocated with devm_*() so
+	 * there is nothing to do here.
+	 */
+
+	return 0;
+}

If the remove function is not needed, it is not needed and should not exist in the first place. Please no dummy functions.

Quoted 8 lines
drivers/hwmon/nsa3xx-hwmon.c new file +8 -0
+
+static struct platform_driver nsa3xx_hwmon_driver = {
+	.probe = nsa3xx_hwmon_probe,
+	.remove = nsa3xx_hwmon_remove,
+	.driver = {
+		.name = "nsa3xx-hwmon",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(of_nsa3xx_hwmon_match),

drivers/hwmon/nsa3xx-hwmon.c line 222

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+	},
+};
+
+module_platform_driver(nsa3xx_hwmon_driver);
+
+MODULE_DEVICE_TABLE(of, of_nsa3xx_hwmon_match);
+MODULE_AUTHOR("Peter Schildmann <[email protected]>");
+MODULE_AUTHOR("Adam Baker <[email protected]>");
+MODULE_DESCRIPTION("NSA3XX Hardware Monitoring");
+MODULE_LICENSE("GPL");

GPL v2

Quoted 4 lines
drivers/hwmon/nsa3xx-hwmon.c new file +1 -0
+MODULE_ALIAS("platform:nsa3xx-hwmon");
Signature · 1 line
2.1.4
author
#5 lore raw

PATCH 2/3 ARM: mvebu: Create a NSA3xx hardware monitoring driver

Quoted 11 lines · Guenter Roeck

Hi,

Quoted 7 lines · Adam Baker

Create a driver to support the hardware monitoring chip present in several models of Zyxel NSA3xx NAS devices.

The driver reads fan speed and temperature from a suitably programmed MCU on the device.

Quoted 8 lines

Please name the driver nsa320. It may ultimately support other devices, but that doesn't mean it is going to support NSA-35x or other future similar devices.

Got the headline, please use

hwmon: Add driver for Zyxel NSA-320

OK

Quoted 18 lines
Quoted 18 lines

---
I've tested this on an NSA-320, I've had someone offer to test it on NSA-325 so hopefully I will get a tested by back.

---
  drivers/hwmon/Kconfig        |  13 +++
  drivers/hwmon/Makefile       |   1 +
  drivers/hwmon/nsa3xx-hwmon.c | 223 +++++++++++++++++++++++++++++++++++++++++++
  3 files changed, 237 insertions(+)

create mode 100644 drivers/hwmon/nsa3xx-hwmon.c

drivers/hwmon/Kconfig +0 -0
index 80a73bf..8801b78 100644
@@ -1757,6 +1757,19 @@ config SENSORS_ULTRA45
  	  This driver provides support for the Ultra45 workstation environmental
  	  sensors.
 
Quoted 3 lines

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1760

Quoted 1 line
drivers/hwmon/Kconfig +1 -0
+config SENSORS_NSA3XX

Please try to stick with alphabetic order.

done

Quoted 4 lines

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1761

Quoted 2 lines
drivers/hwmon/Kconfig +1 -0
+	tristate "ZyXEL NSA3xx fan speed and temperature sensors"

... NSA-320 and compatible ...

done

Quoted 11 lines

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1762

Quoted 2 lines
drivers/hwmon/Kconfig +1 -0
+	depends on GPIOLIB && OF

Can you add some additional dependencies ?

It is quite unlikely that the driver is needed on an X86. Please use at least

	depends on ARM || COMPILE_TEST

or a more specific dependency if the SoC is known. MACH_KIRKWOOD, maybe ?

done - depends on MACH_KIRKWOOD || COMPILE_TEST

Quoted 8 lines

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1765

Quoted 4 lines
drivers/hwmon/Kconfig +3 -0
+	help
+	  If you say yes here you get support for hardware monitoring
+	  for the ZyXEL NSA3XX Media Servers.

Please be specific which devices are supported. Feel free to add "and compatibles", but please no generic and misleading statements such as 3XX.

Changed to NSA320 and compatible and noted NSA325 and some NSA310 variants are probably compatible

Quoted 6 lines

drivers/hwmon/Kconfig config SENSORS_ULTRA45 · line 1769

Quoted 4 lines
drivers/hwmon/Kconfig +4 -0
+
+	  The sensor data is taken from a Holtek HT46R065 microcontroller
+	  connected to GPIO lines.
+

Is that relevant ?

I'm guessing that it is if someone is trying to work out if the unit they've got is likely to be compatible.

Quoted 5 lines
Quoted 5 lines
drivers/hwmon/Kconfig +3 -0
+	  This driver can also be built as a module. If so, the module
+	  will be called nsa3xx-hwmon.
+
  if ACPI
 
Quoted 12 lines

drivers/hwmon/Makefile obj-$(CONFIG_SENSORS_MAX6650) += max6650.o · line 121

Quoted 10 lines
drivers/hwmon/Kconfig +0 -0
  comment "ACPI drivers"
drivers/hwmon/Makefile +1 -0
index 12a3239..e85414a 100644
@@ -118,6 +118,7 @@ obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
  obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o
  obj-$(CONFIG_SENSORS_MAX31790)	+= max31790.o
  obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
+obj-$(CONFIG_SENSORS_NSA3XX)	+= nsa3xx-hwmon.o

Please try to stick with alphabetic order.

done

Quoted 11 lines

drivers/hwmon/nsa3xx-hwmon.c

Quoted 9 lines
drivers/hwmon/Makefile +0 -0
  obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
  obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
  obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
drivers/hwmon/nsa3xx-hwmon.c new file +0 -0
new file mode 100644
index 0000000..0fbf118

nsa320-hwmon.c

done

Quoted 8 lines

drivers/hwmon/nsa3xx-hwmon.c line 4

Quoted 6 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
@@ -0,0 +1,223 @@
+/*
+ * drivers/hwmon/nsa3xx-hwmon.c
+ *
+ * ZyXEL NSA3xx Media Servers

Please be specific.

done

Quoted 23 lines
Quoted 23 lines
drivers/hwmon/nsa3xx-hwmon.c new file +22 -0
+ * hardware monitoring
+ *
+ * Copyright (C) 2016 Adam Baker <[email protected]>
+ * based on a board file driver
+ * Copyright (C) 2012 Peter Schildmann <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License v2 as published by the
+ * Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/hwmon.h>
Quoted 8 lines

drivers/hwmon/nsa3xx-hwmon.c line 33

Quoted 7 lines
drivers/hwmon/nsa3xx-hwmon.c new file +7 -0
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+

Please order include files alphabetically.

done

Quoted 16 lines
Quoted 4 lines
drivers/hwmon/nsa3xx-hwmon.c new file +3 -0
+#define MAGIC_NUMBER 0x55
+
+/*

drivers/hwmon/nsa3xx-hwmon.c line 46

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+ * The Zyxel hwmon MCU is a Holtek HT46R065 that is factory programmed
+ * to perform temperature and fan speed monitoring. It is read by taking
+ * the active pin low. The 32 bit output word is then clocked onto the
+ * data line. The MSB of the data word is a magic nuber to indicate it
+ * has been read correctly, the next byte is the fan speed (in hundreds
+ * of RPM) and the last two bytes are the temperature (in tenths of a
+ * degree)
+ */
+
+struct nsa3xx_hwmon {

s/nsa3xx/nsa320/g for the entire file, please.

done

Quoted 8 lines

drivers/hwmon/nsa3xx-hwmon.c line 50

Quoted 5 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
+	struct device		*classdev;
+	struct mutex		update_lock;	/* lock GPIO operations */
+	unsigned long		last_updated;	/* jiffies */
+	u32			mcu_data;

I would suggest to use unsigned long here. See below for reasons.

I've changed the return value to int

Quoted 10 lines

drivers/hwmon/nsa3xx-hwmon.c line 58

Quoted 8 lines
drivers/hwmon/nsa3xx-hwmon.c new file +8 -0
+	struct gpio_desc	*act;
+	struct gpio_desc	*clk;
+	struct gpio_desc	*data;
+};
+
+enum nsa3xx_inputs {
+	NSA3XX_FAN = 1,
+	NSA3XX_TEMP = 0,

Any special reason for the unusual order ? If yes, please explain.

No, changed

Quoted 25 lines
Quoted 25 lines
drivers/hwmon/nsa3xx-hwmon.c new file +24 -0
+};
+
+static const char * const nsa3xx_input_names[] = {
+	[NSA3XX_FAN] = "Chassis Fan",
+	[NSA3XX_TEMP] = "System Temperature",
+};
+
+/* Although this protocol looks similar to SPI the long delay
+ * between the active (aka chip select) signal and the shorter
+ * delay between clock pulses are needed for reliable operation.
+ * The delays provided are taken from the manufacturer kernel,
+ * testing suggest they probably incorporate a reasonable safety
+ * margin. (The single device tested became unreliable if the
+ * delay was reduced to 1/10th of this value.)
+ */
+static unsigned long nsa3xx_hwmon_update(struct device *dev)
+{
+	u32 mcu_data;
+	u32 mask;
+	struct nsa3xx_hwmon *hwmon = dev_get_drvdata(dev);
+
+	mutex_lock(&hwmon->update_lock);
+
+	mcu_data = hwmon->mcu_data;
Quoted 8 lines

drivers/hwmon/nsa3xx-hwmon.c line 86

Quoted 4 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
+
+	if (time_after(jiffies, hwmon->last_updated + HZ) ||
+							mcu_data == 0) {
+

Please no blank line here. Also, please align continuation lines with '('. However, unless I am missing something, the continuation line is not needed in the first place. Please no unnecessary continuation lines.

done

Quoted 8 lines

drivers/hwmon/nsa3xx-hwmon.c line 90

Quoted 5 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
+		gpiod_set_value(hwmon->act, 1);
+		msleep(100);
+
+		for (mask = BIT(31); mask; mask >>= 1) {

Since you are using BIT(), please include linux/bitops.h.

done

Quoted 18 lines
Quoted 4 lines
drivers/hwmon/nsa3xx-hwmon.c new file +4 -0
+			gpiod_set_value(hwmon->clk, 0);
+			usleep_range(100, 200);
+			gpiod_set_value(hwmon->clk, 1);
+			usleep_range(100, 200);

drivers/hwmon/nsa3xx-hwmon.c line 104

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+			if (gpiod_get_value(hwmon->data))
+				mcu_data |= mask;
+		}
+
+		gpiod_set_value(hwmon->act, 0);
+		dev_dbg(dev, "Read raw MCU data %08x\n", mcu_data);
+
+		if ((mcu_data >> 24) != MAGIC_NUMBER) {
+			dev_err(dev, "Read invalid MCU data %08x\n", mcu_data);
+			mcu_data = 0;

Instead of an error message, it would be better to return an error code (probably -EIO since we don't know better).

Quoted 1 line

The calling code can then return the error to user space.

nsa320_hwmon_update() now returns an int, either 0 or -EIO and the caller can read the data from the nsa320_hwmon structure if it returns
0. dev_err changed to dev_dbg as the raw data is helpful for debugging.

Quoted 30 lines
Quoted 17 lines
drivers/hwmon/nsa3xx-hwmon.c new file +16 -0
+		}
+
+		hwmon->mcu_data = mcu_data;
+		hwmon->last_updated = jiffies;
+	}
+
+	mutex_unlock(&hwmon->update_lock);
+
+	return mcu_data;
+}
+
+static ssize_t show_label(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	int channel = to_sensor_dev_attr(attr)->index;
+

drivers/hwmon/nsa3xx-hwmon.c line 130

Quoted 10 lines
drivers/hwmon/nsa3xx-hwmon.c new file +10 -0
+	return sprintf(buf, "%s\n", nsa3xx_input_names[channel]);
+}
+
+static ssize_t show_value(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	int channel = to_sensor_dev_attr(attr)->index;
+	unsigned long mcu_data = nsa3xx_hwmon_update(dev);
+	unsigned long value = 0;
+

If nsa3xx_hwmon_update() returns an error code, you can use

Quoted 5 lines
	if (IS_ERR_VALUE(mcu_data))
		return (long)mcu_data;

or even better have nsa3xx_hwmon_update() return int directly to indicate an error.

nsa320_hwmon_update() now returns an int error code or zero and the caller gets the data fro the struct if it succeeds

Quoted 6 lines

drivers/hwmon/nsa3xx-hwmon.c line 131

Quoted 2 lines
drivers/hwmon/nsa3xx-hwmon.c new file +1 -0
+	pr_debug("channel value 0x%02x!\n", channel);

Is this really useful ? I would suggest to drop debug messages unless really needed. If you really think the message is useful, please use dev_dbg().

deleted

Quoted 35 lines
Quoted 35 lines
drivers/hwmon/nsa3xx-hwmon.c new file +34 -0
+	switch (channel) {
+	case NSA3XX_TEMP:
+		value = (mcu_data & 0xffff) * 100;
+		break;
+	case NSA3XX_FAN:
+		value = ((mcu_data & 0xff0000) >> 16) * 100;
+		break;
+	}
+	return sprintf(buf, "%lu\n", value);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, NSA3XX_TEMP);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_value, NULL, NSA3XX_TEMP);
+static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, show_label, NULL, NSA3XX_FAN);
+static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_value, NULL, NSA3XX_FAN);
+
+static struct attribute *nsa3xx_attrs[] = {
+	&sensor_dev_attr_temp1_label.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_fan1_label.dev_attr.attr,
+	&sensor_dev_attr_fan1_input.dev_attr.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(nsa3xx);
+
+static const struct of_device_id of_nsa3xx_hwmon_match[] = {
+	{ .compatible = "zyxel,nsa320-mcu", },
+	{ },
+};
+
+static int nsa3xx_hwmon_probe(struct platform_device *pdev)
+{
+	struct nsa3xx_hwmon *hwmon;
Quoted 8 lines

drivers/hwmon/nsa3xx-hwmon.c line 171

Quoted 6 lines
drivers/hwmon/nsa3xx-hwmon.c new file +6 -0
+
+	hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
+	if (!hwmon)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, hwmon);

Unnecessary.

removed

Quoted 16 lines

drivers/hwmon/nsa3xx-hwmon.c line 183

Quoted 13 lines
drivers/hwmon/nsa3xx-hwmon.c new file +12 -0
+
+	/* Look up the GPIO pins to use */
+	hwmon->act = devm_gpiod_get(&pdev->dev, "act", GPIOD_OUT_LOW);
+	hwmon->clk = devm_gpiod_get(&pdev->dev, "clk", GPIOD_OUT_HIGH);
+	hwmon->data = devm_gpiod_get(&pdev->dev, "data", GPIOD_IN);
+
+	if (IS_ERR(hwmon->act))
+		return PTR_ERR(hwmon->act);
+	if (IS_ERR(hwmon->clk))
+		return PTR_ERR(hwmon->clk);
+	if (IS_ERR(hwmon->data))
+		return PTR_ERR(hwmon->data);

Please reorder to have the error checks immediately after the calls to devm_gpiod_get().

done

Quoted 9 lines

drivers/hwmon/nsa3xx-hwmon.c line 188

Quoted 6 lines
drivers/hwmon/nsa3xx-hwmon.c new file +5 -0
+
+	mutex_init(&hwmon->update_lock);
+
+	hwmon->classdev = devm_hwmon_device_register_with_groups(&pdev->dev,
+					"nsa3xx", hwmon, nsa3xx_groups);

classdev is only used in this function and thus does not have to be kept in struct nsa3xx_hwmon.

removed

Quoted 9 lines

drivers/hwmon/nsa3xx-hwmon.c line 193

Quoted 6 lines
drivers/hwmon/nsa3xx-hwmon.c new file +5 -0
+	if (IS_ERR(hwmon->classdev))
+		return PTR_ERR(hwmon->classdev);
+
+	dev_dbg(&pdev->dev, "initialized\n");
+

This message is really unnecessary. Please just use

	return PTR_ERR_OR_ZERO(classdev);

done

Quoted 16 lines

drivers/hwmon/nsa3xx-hwmon.c line 204

Quoted 12 lines
drivers/hwmon/nsa3xx-hwmon.c new file +11 -0
+	return 0;
+}
+
+static int nsa3xx_hwmon_remove(struct platform_device *pdev)
+{
+	/* All resources are allocated with devm_*() so
+	 * there is nothing to do here.
+	 */
+
+	return 0;
+}

If the remove function is not needed, it is not needed and should not exist in the first place. Please no dummy functions.

done, I've left a comment to explain why there is no remove to prompt anyone who changes the code to use devres or add a remove method

Quoted 12 lines
Quoted 12 lines
drivers/hwmon/nsa3xx-hwmon.c new file +12 -0
+
+static struct platform_driver nsa3xx_hwmon_driver = {
+	.probe = nsa3xx_hwmon_probe,
+	.remove = nsa3xx_hwmon_remove,
+	.driver = {
+		.name = "nsa3xx-hwmon",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(of_nsa3xx_hwmon_match),
+	},
+};
+
+module_platform_driver(nsa3xx_hwmon_driver);
Quoted 8 lines

drivers/hwmon/nsa3xx-hwmon.c line 222

Quoted 6 lines
drivers/hwmon/nsa3xx-hwmon.c new file +6 -0
+
+MODULE_DEVICE_TABLE(of, of_nsa3xx_hwmon_match);
+MODULE_AUTHOR("Peter Schildmann <[email protected]>");
+MODULE_AUTHOR("Adam Baker <[email protected]>");
+MODULE_DESCRIPTION("NSA3XX Hardware Monitoring");
+MODULE_LICENSE("GPL");

GPL v2

done

Quoted 5 lines
Quoted 5 lines
drivers/hwmon/nsa3xx-hwmon.c new file +1 -1
+MODULE_ALIAS("platform:nsa3xx-hwmon");
--

2.1.4

author
#6 lore raw

PATCH 3/3 ARM: mvebu: Add the hardware monitor to the NSA320 device tree

In reply to Adam Baker

Add an entry for the hardware monitoring MCU

---
 arch/arm/boot/dts/kirkwood-nsa320.dts | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
arch/arm/boot/dts/kirkwood-nsa320.dts +11 -2
index 24f686d..2a935e9 100644
@@ -193,10 +193,19 @@
 		};
 	};
 
+	hwmon {
+		compatible = "zyxel,nsa320-mcu";
+		pinctrl-0 = <&pmx_mcu_data &pmx_mcu_clk &pmx_mcu_act>;
+		pinctrl-names = "default";
+
+		data-gpios = <&gpio0 14 GPIO_ACTIVE_HIGH>;
+		clk-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+		act-gpios = <&gpio0 17 GPIO_ACTIVE_LOW>;
+	};
+
 	/* The following pins are currently not assigned to a driver,
 	   some of them should be configured as inputs.
-	pinctrl-0 = <&pmx_mcu_data &pmx_mcu_clk &pmx_mcu_act
-		     &pmx_htp &pmx_vid_b1
+	pinctrl-0 = <&pmx_htp &pmx_vid_b1
 		     &pmx_power_resume_data &pmx_power_resume_clk>; */
 };
 
Signature · 1 line
2.1.4
#7 lore raw

cover ARM: mvebu: Add driver for the Zyxel NSA3XX hwmon MCU

In reply to Adam Baker

Hi Adam,

Quoted 10 lines · Adam Baker

This patch series adds a driver to support the hardware monitoring MCU that is present in some models of the Zyxel NSA3xx series of NAS units.

A patch is included to add it to the device tree for the NSA320 model, patches to the other device trees will be included if testers come forward (I already have a possible tester for NSA325).

There are no dependencies between the patches so I guess the first two should go via the hardware monitoring maintainers and the third via the ARM mvebu maintainers.

You are right. However the first tow patch are misnamed, they better should be called:
hwmn: Define binding for the nsa3xx-hwmon driver
hwmn: Create a driver to support the hardware monitoring chip

The last patch seems OK for me, and the binding has been approved. So when you will get a review from the hwmon maintainer, I will apply the last patch in the mvebu tree.

Thanks,

Gregory

Quoted 12 lines

[PATCH 1/3] Define a binding for the hardware monitoring chip present [PATCH 2/3] Create a driver to support the hardware monitoring chip [PATCH 3/3] Add an entry for the hardware monitoring MCU

 Documentation/devicetree/bindings/hwmon/nsa320-mcu.txt |  21 ++++++++
 arch/arm/boot/dts/kirkwood-nsa320.dts                  |  13 ++++-
 drivers/hwmon/Kconfig                                  |  13 +++++
 drivers/hwmon/Makefile                                 |   1 +
 drivers/hwmon/nsa3xx-hwmon.c | 223
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 269 insertions(+), 2 deletions(-)
Signature · 4 lines
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com