Commit acbea679 authored by Matt Ranostay's avatar Matt Ranostay Committed by Mauro Carvalho Chehab

media: video-i2c: add hwmon support for amg88xx

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: default avatarMatt Ranostay <matt.ranostay@konsulko.com>
Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent 22fb5f0f
......@@ -1033,6 +1033,7 @@ config VIDEO_I2C
tristate "I2C transport video support"
depends on VIDEO_V4L2 && I2C
select VIDEOBUF2_VMALLOC
imply HWMON
---help---
Enable the I2C transport video support which supports the
following:
......
......@@ -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 +105,74 @@ static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
return (ret == 2) ? 0 : -EIO;
}
#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, this isn't a two's complement value but an
* absolute temperature that needs to be inverted in the case of being
* negative.
*/
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 +183,7 @@ static const struct video_i2c_chip video_i2c_chip[] = {
.buffer_size = 128,
.bpp = 16,
.xfer = &amg88xx_xfer,
.hwmon_init = amg88xx_hwmon_init,
},
};
......@@ -505,6 +578,14 @@ 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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