diff mbox

[v2] media: video-i2c: add hwmon support for amg88xx

Message ID 20180627041858.22186-1-matt.ranostay@konsulko.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Matt Ranostay June 27, 2018, 4:18 a.m. UTC 
AMG88xx has an on-board thermistor which is used for more accurate
processing of its temperature readings from the 8x8 thermopile array

Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
---
 drivers/media/i2c/video-i2c.c | 77 +++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)

Changes from v1:
* remove unneeded include statement
* removed evil &NULL dereference if hwmon isn't enabled
* return PTR_ERR instead of boolean IS_ERR from amg88xx_hwmon_init()
* use error code returned from hwmon_init() to display dev_warn

Comments

Guenter Roeck June 27, 2018, 5:45 a.m. UTC | #1 
On 06/26/2018 09:18 PM, Matt Ranostay wrote:
> AMG88xx has an on-board thermistor which is used for more accurate
> processing of its temperature readings from the 8x8 thermopile array
> 
> Cc: linux-hwmon@vger.kernel.org
> Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
> ---
>   drivers/media/i2c/video-i2c.c | 77 +++++++++++++++++++++++++++++++++++
>   1 file changed, 77 insertions(+)
> 
> Changes from v1:
> * remove unneeded include statement
> * removed evil &NULL dereference if hwmon isn't enabled
> * return PTR_ERR instead of boolean IS_ERR from amg88xx_hwmon_init()
> * use error code returned from hwmon_init() to display dev_warn
> 
> diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
> index 0b347cc19aa5..834cd4401e38 100644
> --- a/drivers/media/i2c/video-i2c.c
> +++ b/drivers/media/i2c/video-i2c.c
> @@ -10,6 +10,7 @@
>   
>   #include <linux/delay.h>
>   #include <linux/freezer.h>
> +#include <linux/hwmon.h>
>   #include <linux/kthread.h>
>   #include <linux/i2c.h>
>   #include <linux/list.h>
> @@ -77,6 +78,9 @@ struct video_i2c_chip {
>   
>   	/* xfer function */
>   	int (*xfer)(struct video_i2c_data *data, char *buf);
> +
> +	/* hwmon init function */
> +	int (*hwmon_init)(struct video_i2c_data *data);
>   };
>   
>   static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
> @@ -101,6 +105,70 @@ static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
>   	return (ret == 2) ? 0 : -EIO;
>   }
>   
> +#if defined(CONFIG_HWMON) || (defined(MODULE) && defined(CONFIG_HWMON_MODULE))
> +

I must have missed this before, sorry.

Please use "#if IS_ENABLED(CONFIG_HWMON)"

> +static const u32 amg88xx_temp_config[] = {
> +	HWMON_T_INPUT,
> +	0
> +};
> +
> +static const struct hwmon_channel_info amg88xx_temp = {
> +	.type = hwmon_temp,
> +	.config = amg88xx_temp_config,
> +};
> +
> +static const struct hwmon_channel_info *amg88xx_info[] = {
> +	&amg88xx_temp,
> +	NULL
> +};
> +
> +static umode_t amg88xx_is_visible(const void *drvdata,
> +				  enum hwmon_sensor_types type,
> +				  u32 attr, int channel)
> +{
> +	return 0444;
> +}
> +
> +static int amg88xx_read(struct device *dev, enum hwmon_sensor_types type,
> +			u32 attr, int channel, long *val)
> +{
> +	struct video_i2c_data *data = dev_get_drvdata(dev);
> +	struct i2c_client *client = data->client;
> +	int tmp = i2c_smbus_read_word_data(client, 0x0e);
> +
> +	if (tmp < 0)
> +		return tmp;
> +
> +	/* check for sign bit, and invert temp reading to a negative value */

Please add some more detail - it doesn't explain that we are not dealing
with a normal negative number.

> +	if (tmp & BIT(11))
> +		tmp = -(tmp & 0x7ff);
> +
> +	*val = (tmp * 625) / 10;
> +
> +	return 0;
> +}
> +
> +static const struct hwmon_ops amg88xx_hwmon_ops = {
> +	.is_visible = amg88xx_is_visible,
> +	.read = amg88xx_read,
> +};
> +
> +static const struct hwmon_chip_info amg88xx_chip_info = {
> +	.ops = &amg88xx_hwmon_ops,
> +	.info = amg88xx_info,
> +};
> +
> +static int amg88xx_hwmon_init(struct video_i2c_data *data)
> +{
> +	void *hwmon = devm_hwmon_device_register_with_info(&data->client->dev,
> +				"amg88xx", data, &amg88xx_chip_info, NULL);
> +
> +	return PTR_ERR(hwmon);
> +}
> +#else
> +#define	amg88xx_hwmon_init	NULL
> +#endif
> +
>   #define AMG88XX		0
>   
>   static const struct video_i2c_chip video_i2c_chip[] = {
> @@ -111,6 +179,7 @@ static const struct video_i2c_chip video_i2c_chip[] = {
>   		.buffer_size	= 128,
>   		.bpp		= 16,
>   		.xfer		= &amg88xx_xfer,
> +		.hwmon_init	= amg88xx_hwmon_init,
>   	},
>   };
>   
> @@ -505,6 +574,14 @@ static int video_i2c_probe(struct i2c_client *client,
>   	video_set_drvdata(&data->vdev, data);
>   	i2c_set_clientdata(client, data);
>   
> +	if (data->chip->hwmon_init) {
> +		ret = data->chip->hwmon_init(data);
> +		if (ret < 0) {
> +			dev_warn(&client->dev,
> +				 "failed to register hwmon device\n");
> +		}
> +	}
> +
>   	ret = video_register_device(&data->vdev, VFL_TYPE_GRABBER, -1);
>   	if (ret < 0)
>   		goto error_unregister_device;
> 

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diff mbox

Patch

diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
index 0b347cc19aa5..834cd4401e38 100644
--- a/drivers/media/i2c/video-i2c.c
+++ b/drivers/media/i2c/video-i2c.c
@@ -10,6 +10,7 @@ 
 
 #include <linux/delay.h>
 #include <linux/freezer.h>
+#include <linux/hwmon.h>
 #include <linux/kthread.h>
 #include <linux/i2c.h>
 #include <linux/list.h>
@@ -77,6 +78,9 @@  struct video_i2c_chip {
 
 	/* xfer function */
 	int (*xfer)(struct video_i2c_data *data, char *buf);
+
+	/* hwmon init function */
+	int (*hwmon_init)(struct video_i2c_data *data);
 };
 
 static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
@@ -101,6 +105,70 @@  static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
 	return (ret == 2) ? 0 : -EIO;
 }
 
+#if defined(CONFIG_HWMON) || (defined(MODULE) && defined(CONFIG_HWMON_MODULE))
+
+static const u32 amg88xx_temp_config[] = {
+	HWMON_T_INPUT,
+	0
+};
+
+static const struct hwmon_channel_info amg88xx_temp = {
+	.type = hwmon_temp,
+	.config = amg88xx_temp_config,
+};
+
+static const struct hwmon_channel_info *amg88xx_info[] = {
+	&amg88xx_temp,
+	NULL
+};
+
+static umode_t amg88xx_is_visible(const void *drvdata,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	return 0444;
+}
+
+static int amg88xx_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	struct video_i2c_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+	int tmp = i2c_smbus_read_word_data(client, 0x0e);
+
+	if (tmp < 0)
+		return tmp;
+
+	/* check for sign bit, and invert temp reading to a negative value */
+	if (tmp & BIT(11))
+		tmp = -(tmp & 0x7ff);
+
+	*val = (tmp * 625) / 10;
+
+	return 0;
+}
+
+static const struct hwmon_ops amg88xx_hwmon_ops = {
+	.is_visible = amg88xx_is_visible,
+	.read = amg88xx_read,
+};
+
+static const struct hwmon_chip_info amg88xx_chip_info = {
+	.ops = &amg88xx_hwmon_ops,
+	.info = amg88xx_info,
+};
+
+static int amg88xx_hwmon_init(struct video_i2c_data *data)
+{
+	void *hwmon = devm_hwmon_device_register_with_info(&data->client->dev,
+				"amg88xx", data, &amg88xx_chip_info, NULL);
+
+	return PTR_ERR(hwmon);
+}
+#else
+#define	amg88xx_hwmon_init	NULL
+#endif
+
 #define AMG88XX		0
 
 static const struct video_i2c_chip video_i2c_chip[] = {
@@ -111,6 +179,7 @@  static const struct video_i2c_chip video_i2c_chip[] = {
 		.buffer_size	= 128,
 		.bpp		= 16,
 		.xfer		= &amg88xx_xfer,
+		.hwmon_init	= amg88xx_hwmon_init,
 	},
 };
 
@@ -505,6 +574,14 @@  static int video_i2c_probe(struct i2c_client *client,
 	video_set_drvdata(&data->vdev, data);
 	i2c_set_clientdata(client, data);
 
+	if (data->chip->hwmon_init) {
+		ret = data->chip->hwmon_init(data);
+		if (ret < 0) {
+			dev_warn(&client->dev,
+				 "failed to register hwmon device\n");
+		}
+	}
+
 	ret = video_register_device(&data->vdev, VFL_TYPE_GRABBER, -1);
 	if (ret < 0)
 		goto error_unregister_device;