Hi Michele,
On Wed, 05 Aug 2009 17:08:05 +0200, Michele De Candia (VT) wrote:
> Hi all,
> according to the TAOS Application Note 'Controlling a Backlight with the
> TSL2550 Ambient Light Sensor' (page 14), the actual lux value in
> extended mode should be obtained multiplying the calculated lux value by 5.
> The following patch should fix the lux calculation in this case.
>
> Regards,
> Michele De Candia
> --
>
> Signed-off-by: Michele Jr De Candia <[email protected]>
>
> drivers/i2c/chips/tsl2550.c | 7 +++++--
> 1 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/chips/tsl2550.c b/drivers/i2c/chips/tsl2550.c
> index b96f302..04b87e0 100644
> --- a/drivers/i2c/chips/tsl2550.c
> +++ b/drivers/i2c/chips/tsl2550.c
> @@ -279,7 +279,7 @@ static ssize_t __tsl2550_show_lux(struct i2c_client
> *client, char *buf)
> {
> u8 ch0, ch1;
I don't know what your e-mail client is doing to the source code, but
it's bad. It replaces tabs with spaces and folds long lines at least -
I won't be able to apply your patch. Please either fix your client, or
attach the patch instead of inlining it.
> int ret;
> -
> + struct tsl2550_data *data = i2c_get_clientdata(client);
> ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0);
> if (ret < 0)
> return ret;
> @@ -293,7 +293,10 @@ static ssize_t __tsl2550_show_lux(struct i2c_client
> *client, char *buf)
> ch1 = ret;
>
> /* Do the job */
> - ret = tsl2550_calculate_lux(ch0, ch1);
> + if (!data->operating_mode)
> + ret = tsl2550_calculate_lux(ch0, ch1);
> + else
> + ret = tsl2550_calculate_lux(ch0, ch1) * 5;
> if (ret < 0)
> return ret;
Operating on values before you check for errors is wrong. I'd rather do:
ret = tsl2550_calculate_lux(ch0, ch1);
if (ret < 0)
return ret;
if (data->operating_mode == 1) /* extended mode */
ret *= 5;
OK?
--
Jean Delvare
--
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