[PATCH 0/2] hwmon: a new driver for Synaptics AS370 PVT sensor

[PATCH 0/2] hwmon: a new driver for Synaptics AS370 PVT sensor

[Jisheng Zhang]

Add a new driver for Synaptics AS370 PVT sensor. Currently only
temperature is supported.

Jisheng Zhang (2):
  hwmon: Add Synaptics AS370 PVT sensor driver
  hwmon: (as370-hwmon) Add DT bindings for Synaptics AS370 PVT

 .../devicetree/bindings/hwmon/as370.txt       |  11 ++
 drivers/hwmon/Kconfig                         |  10 ++
 drivers/hwmon/Makefile                        |   1 +
 drivers/hwmon/as370-hwmon.c                   | 158 ++++++++++++++++++
 4 files changed, 180 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/as370.txt
 create mode 100644 drivers/hwmon/as370-hwmon.c

-- 
2.23.0.rc1

[PATCH 1/2] hwmon: Add Synaptics AS370 PVT sensor driver

[Jisheng Zhang]

Add a new driver for Synaptics AS370 PVT sensors. Currently, only
temperature is supported.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
---
 drivers/hwmon/Kconfig       |  10 +++
 drivers/hwmon/Makefile      |   1 +
 drivers/hwmon/as370-hwmon.c | 158 ++++++++++++++++++++++++++++++++++++
 3 files changed, 169 insertions(+)
 create mode 100644 drivers/hwmon/as370-hwmon.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 650dd71f9724..d31610933faa 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -246,6 +246,16 @@ config SENSORS_ADT7475
 	  This driver can also be built as a module. If so, the module
 	  will be called adt7475.
 
+config SENSORS_AS370
+	tristate "Synaptics AS370 SoC hardware monitoring driver"
+	help
+	  If you say yes here you get support for the PVT sensors of
+	  the Synaptics AS370 SoC
+
+	  This driver can also be built as a module. If so, the module
+	  will be called as370-hwmon.
+
+
 config SENSORS_ASC7621
 	tristate "Andigilog aSC7621"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 8db472ea04f0..252e8a4c9781 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_SENSORS_ADT7475)	+= adt7475.o
 obj-$(CONFIG_SENSORS_APPLESMC)	+= applesmc.o
 obj-$(CONFIG_SENSORS_ARM_SCMI)	+= scmi-hwmon.o
 obj-$(CONFIG_SENSORS_ARM_SCPI)	+= scpi-hwmon.o
+obj-$(CONFIG_SENSORS_AS370)	+= as370-hwmon.o
 obj-$(CONFIG_SENSORS_ASC7621)	+= asc7621.o
 obj-$(CONFIG_SENSORS_ASPEED)	+= aspeed-pwm-tacho.o
 obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
diff --git a/drivers/hwmon/as370-hwmon.c b/drivers/hwmon/as370-hwmon.c
new file mode 100644
index 000000000000..98dfba45e1b0
--- /dev/null
+++ b/drivers/hwmon/as370-hwmon.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Synaptics AS370 SoC Hardware Monitoring Driver
+ *
+ * Copyright (C) 2018 Synaptics Incorporated
+ * Author: Jisheng Zhang <jszhang@kernel.org>
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/hwmon.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+#define CTRL		0x0
+#define  PD		BIT(0)
+#define  EN		BIT(1)
+#define  T_SEL		BIT(2)
+#define  V_SEL		BIT(3)
+#define  NMOS_SEL	BIT(8)
+#define  PMOS_SEL	BIT(9)
+#define STS		0x4
+#define  BN_MASK	(0xfff << 0)
+#define  EOC		BIT(12)
+
+struct as370_hwmon {
+	void __iomem *base;
+};
+
+static void init_pvt(struct as370_hwmon *hwmon)
+{
+	u32 val;
+	void __iomem *addr = hwmon->base + CTRL;
+
+	val = PD;
+	writel_relaxed(val, addr);
+	val |= T_SEL;
+	val &= ~V_SEL;
+	val &= ~NMOS_SEL;
+	val &= ~PMOS_SEL;
+	writel_relaxed(val, addr);
+	val |= EN;
+	writel_relaxed(val, addr);
+	val &= ~PD;
+	writel_relaxed(val, addr);
+}
+
+static int read_pvt(struct as370_hwmon *hwmon)
+{
+	return readl_relaxed(hwmon->base + STS) & BN_MASK;
+}
+
+static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+			    u32 attr, int channel, long *temp)
+{
+	int val;
+	struct as370_hwmon *hwmon = dev_get_drvdata(dev);
+
+	switch (attr) {
+	case hwmon_temp_input:
+		val = read_pvt(hwmon);
+		if (val < 0)
+			return val;
+		*temp = val * 251802 / 4096 - 85525;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static umode_t
+as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
+		       u32 attr, int channel)
+{
+	if (type != hwmon_temp)
+		return 0;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		return 0444;
+	default:
+		return 0;
+	}
+}
+
+static const u32 as370_hwmon_temp_config[] = {
+	HWMON_T_INPUT,
+	0
+};
+
+static const struct hwmon_channel_info as370_hwmon_temp = {
+	.type = hwmon_temp,
+	.config = as370_hwmon_temp_config,
+};
+
+static const struct hwmon_channel_info *as370_hwmon_info[] = {
+	&as370_hwmon_temp,
+	NULL
+};
+
+static const struct hwmon_ops as370_hwmon_ops = {
+	.is_visible = as370_hwmon_is_visible,
+	.read = as370_hwmon_read,
+};
+
+static const struct hwmon_chip_info as370_chip_info = {
+	.ops = &as370_hwmon_ops,
+	.info = as370_hwmon_info,
+};
+
+static int as370_hwmon_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct device *hwmon_dev;
+	struct as370_hwmon *hwmon;
+	struct device *dev = &pdev->dev;
+
+	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
+	if (!hwmon)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	hwmon->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(hwmon->base))
+		return PTR_ERR(hwmon->base);
+
+	init_pvt(hwmon);
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev,
+							 "as370_hwmon",
+							 hwmon,
+							 &as370_chip_info,
+							 NULL);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct of_device_id as370_hwmon_match[] = {
+	{ .compatible = "syna,as370-hwmon" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, as370_hwmon_match);
+
+static struct platform_driver as370_hwmon_driver = {
+	.probe = as370_hwmon_probe,
+	.driver = {
+		.name = "as370-hwmon",
+		.of_match_table = as370_hwmon_match,
+	},
+};
+module_platform_driver(as370_hwmon_driver);
+
+MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
+MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
+MODULE_LICENSE("GPL v2");
-- 
2.23.0.rc1

[PATCH 2/2] hwmon: (as370-hwmon) Add DT bindings for Synaptics AS370 PVT

[Jisheng Zhang]

Add device tree bindings for Synaptics AS370 PVT sensors.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
---
 Documentation/devicetree/bindings/hwmon/as370.txt | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/as370.txt

diff --git a/Documentation/devicetree/bindings/hwmon/as370.txt b/Documentation/devicetree/bindings/hwmon/as370.txt
new file mode 100644
index 000000000000..d102fe765124
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/as370.txt
@@ -0,0 +1,11 @@
+Bindings for Synaptics AS370 PVT sensors
+
+Required properties:
+- compatible : "syna,as370-hwmon"
+- reg        : address and length of the register set.
+
+Example:
+	hwmon@ea0810 {
+		compatible = "syna,as370-hwmon";
+		reg = <0xea0810 0xc>;
+	};
-- 
2.23.0.rc1

Re: [PATCH 1/2] hwmon: Add Synaptics AS370 PVT sensor driver

[Guenter Roeck]

On 8/26/19 3:01 AM, Jisheng Zhang wrote:
> Add a new driver for Synaptics AS370 PVT sensors. Currently, only
> temperature is supported.
> 
> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
> ---
>   drivers/hwmon/Kconfig       |  10 +++
>   drivers/hwmon/Makefile      |   1 +
>   drivers/hwmon/as370-hwmon.c | 158 ++++++++++++++++++++++++++++++++++++
>   3 files changed, 169 insertions(+)
>   create mode 100644 drivers/hwmon/as370-hwmon.c
> 
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 650dd71f9724..d31610933faa 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -246,6 +246,16 @@ config SENSORS_ADT7475
>   	  This driver can also be built as a module. If so, the module
>   	  will be called adt7475.
>   
> +config SENSORS_AS370
> +	tristate "Synaptics AS370 SoC hardware monitoring driver"

I think this needs "depends on HAS_IOMEM".

> +	help
> +	  If you say yes here you get support for the PVT sensors of
> +	  the Synaptics AS370 SoC
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called as370-hwmon.
> +
> +
>   config SENSORS_ASC7621
>   	tristate "Andigilog aSC7621"
>   	depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 8db472ea04f0..252e8a4c9781 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -48,6 +48,7 @@ obj-$(CONFIG_SENSORS_ADT7475)	+= adt7475.o
>   obj-$(CONFIG_SENSORS_APPLESMC)	+= applesmc.o
>   obj-$(CONFIG_SENSORS_ARM_SCMI)	+= scmi-hwmon.o
>   obj-$(CONFIG_SENSORS_ARM_SCPI)	+= scpi-hwmon.o
> +obj-$(CONFIG_SENSORS_AS370)	+= as370-hwmon.o
>   obj-$(CONFIG_SENSORS_ASC7621)	+= asc7621.o
>   obj-$(CONFIG_SENSORS_ASPEED)	+= aspeed-pwm-tacho.o
>   obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
> diff --git a/drivers/hwmon/as370-hwmon.c b/drivers/hwmon/as370-hwmon.c
> new file mode 100644
> index 000000000000..98dfba45e1b0
> --- /dev/null
> +++ b/drivers/hwmon/as370-hwmon.c
> @@ -0,0 +1,158 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Synaptics AS370 SoC Hardware Monitoring Driver
> + *
> + * Copyright (C) 2018 Synaptics Incorporated
> + * Author: Jisheng Zhang <jszhang@kernel.org>
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/delay.h>

Unnecessary include file.

> +#include <linux/hwmon.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +
> +#define CTRL		0x0
> +#define  PD		BIT(0)
> +#define  EN		BIT(1)
> +#define  T_SEL		BIT(2)
> +#define  V_SEL		BIT(3)
> +#define  NMOS_SEL	BIT(8)
> +#define  PMOS_SEL	BIT(9)
> +#define STS		0x4
> +#define  BN_MASK	(0xfff << 0)

How about using GENMASK() ?

> +#define  EOC		BIT(12)
> +
> +struct as370_hwmon {
> +	void __iomem *base;
> +};
> +
> +static void init_pvt(struct as370_hwmon *hwmon)
> +{
> +	u32 val;
> +	void __iomem *addr = hwmon->base + CTRL;
> +
> +	val = PD;
> +	writel_relaxed(val, addr);
> +	val |= T_SEL;
> +	val &= ~V_SEL;
> +	val &= ~NMOS_SEL;
> +	val &= ~PMOS_SEL;

What is the point of this ? We know that val == PD here.

> +	writel_relaxed(val, addr);
> +	val |= EN;
> +	writel_relaxed(val, addr);
> +	val &= ~PD;
> +	writel_relaxed(val, addr);
> +}
> +
> +static int read_pvt(struct as370_hwmon *hwmon)
> +{
> +	return readl_relaxed(hwmon->base + STS) & BN_MASK;
> +}

Please fold into the calling code.

> +
> +static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> +			    u32 attr, int channel, long *temp)
> +{
> +	int val;
> +	struct as370_hwmon *hwmon = dev_get_drvdata(dev);
> +
> +	switch (attr) {
> +	case hwmon_temp_input:
> +		val = read_pvt(hwmon);
> +		if (val < 0)
> +			return val;

read_pvt() doesn't return a negative error code. This check is unnecessary.

> +		*temp = val * 251802 / 4096 - 85525;

This results in rounding down the reported temperature. It is ok if it is
what you want; otherwise, I would suggest to use DIV_ROUND_CLOSEST().

> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static umode_t
> +as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
> +		       u32 attr, int channel)
> +{
> +	if (type != hwmon_temp)
> +		return 0;
> +
> +	switch (attr) {
> +	case hwmon_temp_input:
> +		return 0444;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static const u32 as370_hwmon_temp_config[] = {
> +	HWMON_T_INPUT,
> +	0
> +};
> +
> +static const struct hwmon_channel_info as370_hwmon_temp = {
> +	.type = hwmon_temp,
> +	.config = as370_hwmon_temp_config,
> +};
> +
> +static const struct hwmon_channel_info *as370_hwmon_info[] = {
> +	&as370_hwmon_temp,
> +	NULL
> +};
> +
> +static const struct hwmon_ops as370_hwmon_ops = {
> +	.is_visible = as370_hwmon_is_visible,
> +	.read = as370_hwmon_read,
> +};
> +
> +static const struct hwmon_chip_info as370_chip_info = {
> +	.ops = &as370_hwmon_ops,
> +	.info = as370_hwmon_info,
> +};
> +
> +static int as370_hwmon_probe(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +	struct device *hwmon_dev;
> +	struct as370_hwmon *hwmon;
> +	struct device *dev = &pdev->dev;
> +
> +	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
> +	if (!hwmon)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	hwmon->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(hwmon->base))
> +		return PTR_ERR(hwmon->base);
> +
> +	init_pvt(hwmon);
> +
> +	hwmon_dev = devm_hwmon_device_register_with_info(dev,
> +							 "as370_hwmon",

The "_hwmon" seems unnecessary. It will show up in "sensors" as part
of the sensor name. Is this really what you want ?

> +							 hwmon,
> +							 &as370_chip_info,
> +							 NULL);
> +	return PTR_ERR_OR_ZERO(hwmon_dev);
> +}
> +
> +static const struct of_device_id as370_hwmon_match[] = {
> +	{ .compatible = "syna,as370-hwmon" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, as370_hwmon_match);
> +
> +static struct platform_driver as370_hwmon_driver = {
> +	.probe = as370_hwmon_probe,
> +	.driver = {
> +		.name = "as370-hwmon",
> +		.of_match_table = as370_hwmon_match,
> +	},
> +};
> +module_platform_driver(as370_hwmon_driver);
> +
> +MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
> +MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
> +MODULE_LICENSE("GPL v2");
> 

Re: [PATCH 1/2] hwmon: Add Synaptics AS370 PVT sensor driver

[Jisheng Zhang]

Hi Guenter,

On Mon, 26 Aug 2019 06:44:34 -0700 Guenter Roeck wrote:

> 
> 
> On 8/26/19 3:01 AM, Jisheng Zhang wrote:
> > Add a new driver for Synaptics AS370 PVT sensors. Currently, only
> > temperature is supported.
> >
> > Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
> > ---
> >   drivers/hwmon/Kconfig       |  10 +++
> >   drivers/hwmon/Makefile      |   1 +
> >   drivers/hwmon/as370-hwmon.c | 158 ++++++++++++++++++++++++++++++++++++
> >   3 files changed, 169 insertions(+)
> >   create mode 100644 drivers/hwmon/as370-hwmon.c
> >
> > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> > index 650dd71f9724..d31610933faa 100644
> > --- a/drivers/hwmon/Kconfig
> > +++ b/drivers/hwmon/Kconfig
> > @@ -246,6 +246,16 @@ config SENSORS_ADT7475
> >         This driver can also be built as a module. If so, the module
> >         will be called adt7475.
> >
> > +config SENSORS_AS370
> > +     tristate "Synaptics AS370 SoC hardware monitoring driver"  
> 
> I think this needs "depends on HAS_IOMEM".

HWMON depends on HAS_IOMEM, so the dependency has been required
by the common HWMON, we don't need it here.

> 
> > +     help
> > +       If you say yes here you get support for the PVT sensors of
> > +       the Synaptics AS370 SoC
> > +
> > +       This driver can also be built as a module. If so, the module
> > +       will be called as370-hwmon.
> > +
> > +
> >   config SENSORS_ASC7621
> >       tristate "Andigilog aSC7621"
> >       depends on I2C
> > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> > index 8db472ea04f0..252e8a4c9781 100644
> > --- a/drivers/hwmon/Makefile
> > +++ b/drivers/hwmon/Makefile
> > @@ -48,6 +48,7 @@ obj-$(CONFIG_SENSORS_ADT7475)       += adt7475.o
> >   obj-$(CONFIG_SENSORS_APPLESMC)      += applesmc.o
> >   obj-$(CONFIG_SENSORS_ARM_SCMI)      += scmi-hwmon.o
> >   obj-$(CONFIG_SENSORS_ARM_SCPI)      += scpi-hwmon.o
> > +obj-$(CONFIG_SENSORS_AS370)  += as370-hwmon.o
> >   obj-$(CONFIG_SENSORS_ASC7621)       += asc7621.o
> >   obj-$(CONFIG_SENSORS_ASPEED)        += aspeed-pwm-tacho.o
> >   obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o
> > diff --git a/drivers/hwmon/as370-hwmon.c b/drivers/hwmon/as370-hwmon.c
> > new file mode 100644
> > index 000000000000..98dfba45e1b0
> > --- /dev/null
> > +++ b/drivers/hwmon/as370-hwmon.c
> > @@ -0,0 +1,158 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Synaptics AS370 SoC Hardware Monitoring Driver
> > + *
> > + * Copyright (C) 2018 Synaptics Incorporated
> > + * Author: Jisheng Zhang <jszhang@kernel.org>
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/delay.h>  
> 
> Unnecessary include file.

will remove it in newer version.

> 
> > +#include <linux/hwmon.h>
> > +#include <linux/init.h>
> > +#include <linux/io.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +
> > +#define CTRL         0x0
> > +#define  PD          BIT(0)
> > +#define  EN          BIT(1)
> > +#define  T_SEL               BIT(2)
> > +#define  V_SEL               BIT(3)
> > +#define  NMOS_SEL    BIT(8)
> > +#define  PMOS_SEL    BIT(9)
> > +#define STS          0x4
> > +#define  BN_MASK     (0xfff << 0)  
> 
> How about using GENMASK() ?

Good idea.

> 
> > +#define  EOC         BIT(12)
> > +
> > +struct as370_hwmon {
> > +     void __iomem *base;
> > +};
> > +
> > +static void init_pvt(struct as370_hwmon *hwmon)
> > +{
> > +     u32 val;
> > +     void __iomem *addr = hwmon->base + CTRL;
> > +
> > +     val = PD;
> > +     writel_relaxed(val, addr);
> > +     val |= T_SEL;
> > +     val &= ~V_SEL;
> > +     val &= ~NMOS_SEL;
> > +     val &= ~PMOS_SEL;  
> 
> What is the point of this ? We know that val == PD here.

yes, could be removed

> 
> > +     writel_relaxed(val, addr);
> > +     val |= EN;
> > +     writel_relaxed(val, addr);
> > +     val &= ~PD;
> > +     writel_relaxed(val, addr);
> > +}
> > +
> > +static int read_pvt(struct as370_hwmon *hwmon)
> > +{
> > +     return readl_relaxed(hwmon->base + STS) & BN_MASK;
> > +}  
> 
> Please fold into the calling code.
> 
> > +
> > +static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> > +                         u32 attr, int channel, long *temp)
> > +{
> > +     int val;
> > +     struct as370_hwmon *hwmon = dev_get_drvdata(dev);
> > +
> > +     switch (attr) {
> > +     case hwmon_temp_input:
> > +             val = read_pvt(hwmon);
> > +             if (val < 0)
> > +                     return val;  
> 
> read_pvt() doesn't return a negative error code. This check is unnecessary.
> 
> > +             *temp = val * 251802 / 4096 - 85525;  
> 
> This results in rounding down the reported temperature. It is ok if it is
> what you want; otherwise, I would suggest to use DIV_ROUND_CLOSEST().

Good idea.

Thanks for your review,
Jisheng

> 
> > +             break;
> > +     default:
> > +             return -EOPNOTSUPP;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static umode_t
> > +as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
> > +                    u32 attr, int channel)
> > +{
> > +     if (type != hwmon_temp)
> > +             return 0;
> > +
> > +     switch (attr) {
> > +     case hwmon_temp_input:
> > +             return 0444;
> > +     default:
> > +             return 0;
> > +     }
> > +}
> > +
> > +static const u32 as370_hwmon_temp_config[] = {
> > +     HWMON_T_INPUT,
> > +     0
> > +};
> > +
> > +static const struct hwmon_channel_info as370_hwmon_temp = {
> > +     .type = hwmon_temp,
> > +     .config = as370_hwmon_temp_config,
> > +};
> > +
> > +static const struct hwmon_channel_info *as370_hwmon_info[] = {
> > +     &as370_hwmon_temp,
> > +     NULL
> > +};
> > +
> > +static const struct hwmon_ops as370_hwmon_ops = {
> > +     .is_visible = as370_hwmon_is_visible,
> > +     .read = as370_hwmon_read,
> > +};
> > +
> > +static const struct hwmon_chip_info as370_chip_info = {
> > +     .ops = &as370_hwmon_ops,
> > +     .info = as370_hwmon_info,
> > +};
> > +
> > +static int as370_hwmon_probe(struct platform_device *pdev)
> > +{
> > +     struct resource *res;
> > +     struct device *hwmon_dev;
> > +     struct as370_hwmon *hwmon;
> > +     struct device *dev = &pdev->dev;
> > +
> > +     hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
> > +     if (!hwmon)
> > +             return -ENOMEM;
> > +
> > +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +     hwmon->base = devm_ioremap_resource(&pdev->dev, res);
> > +     if (IS_ERR(hwmon->base))
> > +             return PTR_ERR(hwmon->base);
> > +
> > +     init_pvt(hwmon);
> > +
> > +     hwmon_dev = devm_hwmon_device_register_with_info(dev,
> > +                                                      "as370_hwmon",  
> 
> The "_hwmon" seems unnecessary. It will show up in "sensors" as part
> of the sensor name. Is this really what you want ?
> 
> > +                                                      hwmon,
> > +                                                      &as370_chip_info,
> > +                                                      NULL);
> > +     return PTR_ERR_OR_ZERO(hwmon_dev);
> > +}
> > +
> > +static const struct of_device_id as370_hwmon_match[] = {
> > +     { .compatible = "syna,as370-hwmon" },
> > +     {},
> > +};
> > +MODULE_DEVICE_TABLE(of, as370_hwmon_match);
> > +
> > +static struct platform_driver as370_hwmon_driver = {
> > +     .probe = as370_hwmon_probe,
> > +     .driver = {
> > +             .name = "as370-hwmon",
> > +             .of_match_table = as370_hwmon_match,
> > +     },
> > +};
> > +module_platform_driver(as370_hwmon_driver);
> > +
> > +MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
> > +MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
> > +MODULE_LICENSE("GPL v2");
> >  
> 

Re: [PATCH 1/2] hwmon: Add Synaptics AS370 PVT sensor driver

[Guenter Roeck]

On 8/26/19 8:02 PM, Jisheng Zhang wrote:
> Hi Guenter,
> 
> On Mon, 26 Aug 2019 06:44:34 -0700 Guenter Roeck wrote:
> 
>>
>>
>> On 8/26/19 3:01 AM, Jisheng Zhang wrote:
>>> Add a new driver for Synaptics AS370 PVT sensors. Currently, only
>>> temperature is supported.
>>>
>>> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
>>> ---
>>>    drivers/hwmon/Kconfig       |  10 +++
>>>    drivers/hwmon/Makefile      |   1 +
>>>    drivers/hwmon/as370-hwmon.c | 158 ++++++++++++++++++++++++++++++++++++
>>>    3 files changed, 169 insertions(+)
>>>    create mode 100644 drivers/hwmon/as370-hwmon.c
>>>
>>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>>> index 650dd71f9724..d31610933faa 100644
>>> --- a/drivers/hwmon/Kconfig
>>> +++ b/drivers/hwmon/Kconfig
>>> @@ -246,6 +246,16 @@ config SENSORS_ADT7475
>>>          This driver can also be built as a module. If so, the module
>>>          will be called adt7475.
>>>
>>> +config SENSORS_AS370
>>> +     tristate "Synaptics AS370 SoC hardware monitoring driver"
>>
>> I think this needs "depends on HAS_IOMEM".
> 
> HWMON depends on HAS_IOMEM, so the dependency has been required
> by the common HWMON, we don't need it here.
> 

This is so wrong :-(. As if I2C or SPI based sensor chips would
require iomem. Oh well, no one complained in 12+ years, so I guess
we are "fine", at least for the time being.

Thanks for noticing.

Guenter