Hi Josh,
On Sun, Jul 14, 2013 at 04:04:29PM +0800, Josh Wu wrote:
> AT91 ADC hardware integrate touch screen support. So this patch add touch
> screen support for at91 adc iio driver.
> To enable touch screen support in adc, you need to add the dt parameters:
> which type of touch are used? (4 or 5 wires), sample period time,
> pen detect debounce time, average samples and pen detect resistor.
>
> In the meantime, since touch screen will use a interal period trigger of adc,
> so it is conflict to other hardware triggers. Driver will disable the hardware
> trigger support if touch screen is enabled.
>
> This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK.
>
> Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---
> .../devicetree/bindings/arm/atmel-adc.txt | 13 +
> arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++
> drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++--
> 3 files changed, 412 insertions(+), 24 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt
> index 0db2945..925d656 100644
> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt
> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt
> @@ -29,6 +29,19 @@ Optional properties:
> - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds
> - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default
> adc_op_clk.
> + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support
> + 4 and 5 wires touch screen.
> + NOTE: when adc touch screen enabled, the adc hardware trigger will be
> + disabled. Since touch screen will occupied the trigger register.
> + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen
> + detect.
> + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for
> + touch screen
> + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged.
> + 0 means no average. 1 means average two samples. 2 means average four
> + samples. 3 means average eight samples.
> + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor.
> + It can be 0, 1, 2, 3.
Could you expand a bit on what are these properties for? Are they
board-specific? IP-specific?
[...]
> +#define DRIVER_NAME "at91_adc"
This looks like this part doesn't belong to another cleanup patch.
> +#define MAX_POS_BITS 12
> +
> +#define ZTHRESHOLD 9000
> +
> struct at91_adc_caps {
> + bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */
Isn't that redundant with the low_res boolean?
> bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */
> u32 mr_prescal_mask;
> u32 mr_startup_mask;
> };
>
> +enum atmel_adc_ts_type {
> + ATMEL_ADC_TOUCHSCREEN_NONE = 0,
> + ATMEL_ADC_TOUCHSCREEN_4WIRE,
> + ATMEL_ADC_TOUCHSCREEN_5WIRE,
> +};
> +
> struct at91_adc_state {
> struct clk *adc_clk;
> u32 adc_clk_rate;
> @@ -70,6 +83,29 @@ struct at91_adc_state {
> bool low_res; /* the resolution corresponds to the lowest one */
> wait_queue_head_t wq_data_avail;
> struct at91_adc_caps caps;
> +
> + /*
> + * Following ADC channels are shared by touchscreen:
> + *
> + * CH0 -- Touch screen XP/UL
> + * CH1 -- Touch screen XM/UR
> + * CH2 -- Touch screen YP/LL
> + * CH3 -- Touch screen YM/Sense
> + * CH4 -- Touch screen LR(5-wire only)
> + *
> + * The bitfields below represents the reserved channel in the
> + * touchscreen mode.
> + */
> +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0)
> +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0)
> + enum atmel_adc_ts_type touchscreen_type;
> + struct input_dev *ts_input;
> +
> + u8 ts_filter_average;
> + u16 ts_pen_detect_debounce;
> + u8 ts_pen_detect_sensitivity;
> + u16 ts_sample_period_time;
> + u16 ts_sample_period_val;
> };
>
> static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
> @@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
> return IRQ_HANDLED;
> }
>
> -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
> +/* Handler for classic adc channel eoc trigger */
> +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
> {
> - struct iio_dev *idev = private;
> struct at91_adc_state *st = iio_priv(idev);
> - u32 status = at91_adc_readl(st, st->registers->status_register);
> -
> - if (!(status & st->registers->drdy_mask))
> - return IRQ_HANDLED;
Why are you changing the prototype and remove most of the useful part
out of the handler?
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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