On 05/09/16 09:26, Nicolas Ferre wrote:
> Le 03/09/2016 à 18:24, Jonathan Cameron a écrit :
>> On 30/08/16 13:27, Nicolas Ferre wrote:
>>> On newer components compatible with the at91sam9x5, the Touchscreen
>>> Switches Closure Time or TSSCTIM value of the Touchscreen Mode Register is
>>> not filled at all.
>>> On some hardware, having no time indicated for it may lead to incoherent
>>> values and jitter.
>>> We fix this time to 10us as it is usually difficult to retrieve impedance
>>> values from LCD manufacturers.
>>>
>>> Signed-off-by: Nicolas Ferre <[email protected]>
>> Hi Nicolas,
>>
>> Stable / fixes material or just have it head for the next merge window?
>
> Well, I would say that it's an addition of a feature that fixes a bad
> behavior ;-)
> So, in summary, I would just add it to next kernel revision.
>
> Thanks for the heads-up. Bye,
Thanks
Applied to the togreg branch of iio.git - initially pushed out
as testing for the autobuilders to play with it.
Jonathan
>
>
>>> ---
>>> drivers/iio/adc/at91_adc.c | 13 +++++++++++++
>>> 1 file changed, 13 insertions(+)
>>>
>>> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
>>> index 0438c68015e8..bbdac07f4aaa 100644
>>> --- a/drivers/iio/adc/at91_adc.c
>>> +++ b/drivers/iio/adc/at91_adc.c
>>> @@ -113,6 +113,7 @@
>>> #define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages
>>> samples */
>>> #define AT91_ADC_TSMR_TSAV_(x) ((x) << 4)
>>> #define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch
>>> closure time */
>>> +#define AT91_ADC_TSMR_SCTIM_(x) ((x) << 16)
>>> #define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce
>>> time */
>>> #define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28)
>>> #define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No
>>> Touchscreen DMA */
>>> @@ -150,6 +151,7 @@
>>> #define MAX_RLPOS_BITS 10
>>> #define TOUCH_SAMPLE_PERIOD_US_RL 10000 /* 10ms, the SoC can't keep
>>> up with 2ms */
>>> #define TOUCH_SHTIM 0xa
>>> +#define TOUCH_SCTIM_US 10 /* 10us for the
>>> Touchscreen Switches Closure Time */
>>>
>>> /**
>>> * struct at91_adc_reg_desc - Various informations relative to registers
>>> @@ -1001,7 +1003,9 @@ static void atmel_ts_close(struct input_dev *dev)
>>>
>>> static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
>>> {
>>> + struct iio_dev *idev = iio_priv_to_dev(st);
>>> u32 reg = 0;
>>> + u32 tssctim = 0;
>>> int i = 0;
>>>
>>> /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
>>> @@ -1034,11 +1038,20 @@ static int at91_ts_hw_init(struct at91_adc_state
>>> *st, u32 adc_clk_khz)
>>> return 0;
>>> }
>>>
>>> + /* Touchscreen Switches Closure time needed for allowing the value to
>>> + * stabilize.
>>> + * Switch Closure Time = (TSSCTIM * 4) ADCClock periods
>>> + */
>>> + tssctim = DIV_ROUND_UP(TOUCH_SCTIM_US * adc_clk_khz / 1000, 4);
>>> + dev_dbg(&idev->dev, "adc_clk at: %d KHz, tssctim at: %d\n",
>>> + adc_clk_khz, tssctim);
>>> +
>>> if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
>>> reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
>>> else
>>> reg = AT91_ADC_TSMR_TSMODE_5WIRE;
>>>
>>> + reg |= AT91_ADC_TSMR_SCTIM_(tssctim) & AT91_ADC_TSMR_SCTIM;
>>> reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
>>> & AT91_ADC_TSMR_TSAV;
>>> reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
>>>
>>
>>
>
>
