On Wed, Jun 27, 2018 at 11:12:43AM -0700, 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: [email protected] > Signed-off-by: Matt Ranostay <[email protected]>
Acked-by: Guenter Roeck <[email protected]> > --- > drivers/media/i2c/video-i2c.c | 81 +++++++++++++++++++++++++++++++++++ > 1 file changed, 81 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 > > Changes from v2: > * change #ifdef check to use cleaner IS_ENABLED(CONFIG_HWMON) > * document why the temperature value isn't sign extended more concisely > > diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c > index 0b347cc19aa5..7dc9338502e5 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 +105,74 @@ 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; > -- > 2.17.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
