On 10/19/2012 02:12 AM, Kim, Milo wrote:
> To get the battery voltage and temperature, IIO ADC functions are used.
> LP8788 ADC driver provides RAW and SCALE channel information.
> This patch fixes wrong ADC result.
>
> Patch v2.
> Use simple iio_read_channel_processed() function rather than
> iio_read_channel_raw() and _scale().
>
> Fix the result type of ADC function as a signed integer.
> Because power_supply_propval.intval and the return value of
> iio_read_channel_processed() are a signed integer,
> 'unsigned int' are replaced with 'int'.
>
> Patch v1.
> Fix wrong ADC results using iio_read_channel_raw() and _scale().
>
> Signed-off-by: Milo(Woogyom) Kim <milo....@ti.com>
Looks good to me, fwiw:
Reviewed-by Lars-Peter Clausen <l...@metafoo.de>
But there is one issue, but this is not necessarily related to this patch,
more inline.
> ---
> drivers/power/lp8788-charger.c | 26 +++++++-------------------
> 1 file changed, 7 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/power/lp8788-charger.c b/drivers/power/lp8788-charger.c
> index 02fc9ab..f18ec8f 100644
> --- a/drivers/power/lp8788-charger.c
> +++ b/drivers/power/lp8788-charger.c
> @@ -235,25 +235,14 @@ static int lp8788_get_battery_present(struct
> lp8788_charger *pchg,
> return 0;
> }
>
[...]
> static int lp8788_get_battery_voltage(struct lp8788_charger *pchg,
> @@ -268,7 +257,7 @@ static int lp8788_get_battery_capacity(struct
> lp8788_charger *pchg,
> struct lp8788 *lp = pchg->lp;
> struct lp8788_charger_platform_data *pdata = pchg->pdata;
> unsigned int max_vbatt;
> - unsigned int vbatt;
> + int vbatt;
> enum lp8788_charging_state state;
> u8 data;
> int ret;
> @@ -304,19 +293,18 @@ static int lp8788_get_battery_temperature(struct
> lp8788_charger *pchg,
> union power_supply_propval *val)
> {
> struct iio_channel *channel = pchg->chan[LP8788_BATT_TEMP];
> - int scaleint;
> - int scalepart;
> + int result;
> int ret;
>
> if (!channel)
> return -EINVAL;
>
> - ret = iio_read_channel_scale(channel, &scaleint, &scalepart);
> - if (ret != IIO_VAL_INT_PLUS_MICRO)
> + ret = iio_read_channel_processed(channel, &result);
> + if (ret < 0)
> return -EINVAL;
>
> /* unit: 0.1 'C */
> - val->intval = (scaleint + scalepart * 1000000) / 100;
> + val->intval = result * 10;
IIO reports temperatures in milli degree Celsius. So it should be multiplied
by 100 to get tenth degree like the power supply framework expects it. But
this might be a issue in your IIO driver reporting the wrong scale.
- Lars
>
> return 0;
> }
--
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