Re: [PATCH 3/4] extcon: arizona: Update manual headphone detection calculation

From: Charles Keepax
Date: Fri May 30 2014 - 05:42:50 EST


On Fri, May 30, 2014 at 10:27:35AM +0900, Chanwoo Choi wrote:
> Hi Charles,
>
> On 05/30/2014 12:27 AM, Charles Keepax wrote:
> > The higher levels of impedance have a higher minimum value than the
> > first level. As the same value was used for all levels, higher impedances
> > were reported with a very low level of accuracy. This patch applies the
> > approriate lower threshold for each level.
> >
> > Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/extcon/extcon-arizona.c | 13 ++++++++-----
> > 1 files changed, 8 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
> > index f2c36b1..c1c8647 100644
> > --- a/drivers/extcon/extcon-arizona.c
> > +++ b/drivers/extcon/extcon-arizona.c
> > @@ -329,12 +329,13 @@ static void arizona_stop_mic(struct arizona_extcon_info *info)
> > }
> >
> > static struct {
> > + unsigned int threshold;
> > unsigned int factor_a;
> > unsigned int factor_b;
> > } arizona_hpdet_b_ranges[] = {
> > - { 5528, 362464 },
> > - { 11084, 6186851 },
> > - { 11065, 65460395 },
> > + { 100, 5528, 362464 },
> > + { 169, 11084, 6186851 },
> > + { 169, 11065, 65460395 },
>
> If you possible, I want to know the 'unit' of the variable(factor_a, factor_b).

I am not sure there are really especially sensible units to give.

>
> > };
> >
> > static struct {
> > @@ -391,7 +392,8 @@ static int arizona_hpdet_read(struct arizona_extcon_info *info)
> > >> ARIZONA_HP_IMPEDANCE_RANGE_SHIFT;
> >
> > if (range < ARRAY_SIZE(arizona_hpdet_b_ranges) - 1 &&
> > - (val < 100 || val >= 0x3fb)) {
> > + (val < arizona_hpdet_b_ranges[range].threshold ||
> > + val >= 0x3fb)) {
>
> I don't understand the meaning of 0x3fb hex value.
> I prefer to define constant variable for readability.

Thats fine I can add a define as part of this patch.

Thanks,
Charles
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