[PATCH 5/5] iio: at91: introduce touch screen support in iio adc driver

Mark Rutland mark.rutland at arm.com
Thu Jul 25 12:45:03 EDT 2013


On Thu, Jul 25, 2013 at 08:56:38AM +0100, Josh Wu wrote:
> Hi, Dear Mark
> 
> On 7/22/2013 9:17 PM, Mark Rutland wrote:
> > On Sun, Jul 14, 2013 at 09:04:29AM +0100, 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 at atmel.com>
> >> Cc: Dmitry Torokhov <dmitry.torokhov at gmail.com>
> >> ---
> >>   .../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.
> > Are 4 and 5 wire configurations that can exist, or the only ones
> > supported by the driver?
> 
> It can be set:
> 
> atmel,adc-touchscreen-wires = <4>;
> or
> atmel,adc-touchscreen-wires = <5>;
> 
> according to your touch screen.

That doesn't answer my question.

Is it possible that 3 or 6 wire configurations might exist, for example,
even if not supported by this driver? Or does the design of the adc
prevent this?

Is there any documentation that might make this clearer?

> 
> >
> >> +    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.
> > For consistency with the adc-touchscreen-wires property, and  other
> > properties with timing information, how about
> > atmel,adc-touchscreen-debounce-delay-us ?
> 
> sound nice to me.

Additionally, is this likely to vary from board to board? This feels
like configuration that could be done based on the compatible string...

> 
> >
> >> +  - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for
> >> +                                    touch screen
> > Again, please be consistent with ts or touchscreen. It may also be good
> > to have -us to make the units explicit (though it does leave the
> > property name being quite a mothful):
> >
> > atmel,adc-touchscreen-sample-period-us ?
> 
> nice. I will use this one.

Looking again at the driver code, it looks like a value derived from
this eventually gets written to the hardware. Is this a fixed value at
integration time, or is this a configuration value? If it's the latter,
can the driver not derive a good value for this itself?

> 
> >
> >> +  - 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.
> > Is this averaging done in the hardware, or the kernel driver?
> 
> It is done in the hardware.

Similarly, this seems to eventually get written to hardware, and thus
seems more like configuration than hardware description. Why does this
need to be in the DT?

As an aside, in general it's nicer to describe a property as a logical
value rather than the raw value that gets programmed into hardware (e.g.
this property could by 2, 4, or 8 rather than 1, 2, or 4).

> But for some soc, like AT91SAM9G45, hardware doesn't support hardware
> average.
> So I am wondering use it as for both hardware and softer average.
> 
> BTW, you mentioned the kernel driver, do you mean a filter algorithm is
> already implemented in kernel library?

I do not know of any such filter algorithm in the kernel, though there
may be one. I was simply confused as to what this was used for.

> 
> >
> > If it's the latter, this can be left for the kernel to decide.
> >
> >> +  - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor.
> >> +    It can be 0, 1, 2, 3.
> > I think "pendet" is a bit opaque. "pen-detect" may be better.
> 
> yes. I'll change this.
> 
> > What
> > physical property does this represent (are these discrete values, or an
> > enumeration)?
> 
> This property is supported by hardware, it can change the adc internal
> resistor value for better pen detection,
>       * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
> In general, we just use default value 2 for 100kOhm.

This value eventually gets written to hardware, and seems more like
configuration than hardware description. Why does this need to be in the
DT?

Thanks,
Mark.

> I think I need add more detail infomation in the dt document.
> 
> Thanks again,
> Best Regards,
> Josh Wu
> 
> >
> > Thanks,
> > Mark.
> >
> >>   Optional trigger Nodes:
> >>     - Required properties:
> >> diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h
> >> index ab273ee..6d6cc14 100644
> >> --- a/arch/arm/mach-at91/include/mach/at91_adc.h
> >> +++ b/arch/arm/mach-at91/include/mach/at91_adc.h
> >> @@ -57,10 +57,44 @@
> >>   #define AT91_ADC_IER           0x24            /* Interrupt Enable Register */
> >>   #define AT91_ADC_IDR           0x28            /* Interrupt Disable Register */
> >>   #define AT91_ADC_IMR           0x2C            /* Interrupt Mask Register */
> >> +#define                AT91_ADC_IER_PEN        (1 << 29)
> >> +#define                AT91_ADC_IER_NOPEN      (1 << 30)
> >> +#define                AT91_ADC_IER_XRDY       (1 << 20)
> >> +#define                AT91_ADC_IER_YRDY       (1 << 21)
> >> +#define                AT91_ADC_IER_PRDY       (1 << 22)
> >> +#define                AT91_ADC_ISR_PENS       (1 << 31)
> >>
> >>   #define AT91_ADC_CHR(n)                (0x30 + ((n) * 4))      /* Channel Data Register N */
> >>   #define                AT91_ADC_DATA           (0x3ff)
> >>
> >> +#define AT91_ADC_ACR           0x94    /* Analog Control Register */
> >> +#define                AT91_ADC_ACR_PENDETSENS (0x3 << 0)      /* pull-up resistor */
> >> +
> >> +#define AT91_ADC_TSMR          0xB0
> >> +#define                AT91_ADC_TSMR_TSMODE    (3 << 0)        /* Touch Screen Mode */
> >> +#define                        AT91_ADC_TSMR_TSMODE_NONE               (0 << 0)
> >> +#define                        AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS     (1 << 0)
> >> +#define                        AT91_ADC_TSMR_TSMODE_4WIRE_PRESS        (2 << 0)
> >> +#define                        AT91_ADC_TSMR_TSMODE_5WIRE              (3 << 0)
> >> +#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_PENDBC    (0x0f << 28)    /* Pen Debounce time */
> >> +#define                        AT91_ADC_TSMR_PENDBC_(x)        ((x) << 28)
> >> +#define                AT91_ADC_TSMR_NOTSDMA   (1 << 22)       /* No Touchscreen DMA */
> >> +#define                AT91_ADC_TSMR_PENDET_DIS        (0 << 24)       /* Pen contact detection disable */
> >> +#define                AT91_ADC_TSMR_PENDET_ENA        (1 << 24)       /* Pen contact detection enable */
> >> +
> >> +#define AT91_ADC_TSXPOSR       0xB4
> >> +#define AT91_ADC_TSYPOSR       0xB8
> >> +#define AT91_ADC_TSPRESSR      0xBC
> >> +
> >>   #define AT91_ADC_VERSION       0xFC
> >>
> >> +/* Trigger Register bit field */
> >> +#define                AT91_ADC_TRGR_TRGPER    (0xffff << 16)
> >> +#define                        AT91_ADC_TRGR_TRGPER_(x)        ((x) << 16)
> >> +#define                AT91_ADC_TRGR_TRGMOD    (0x7 << 0)
> >> +#define                        AT91_ADC_TRGR_MOD_PERIOD_TRIG   (5 << 0)
> >> +
> >>   #endif
> >> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> >> index 8f1386f..ffc0e42 100644
> >> --- a/drivers/iio/adc/at91_adc.c
> >> +++ b/drivers/iio/adc/at91_adc.c
> >> @@ -11,6 +11,7 @@
> >>   #include <linux/clk.h>
> >>   #include <linux/err.h>
> >>   #include <linux/io.h>
> >> +#include <linux/input.h>
> >>   #include <linux/interrupt.h>
> >>   #include <linux/jiffies.h>
> >>   #include <linux/kernel.h>
> >> @@ -39,12 +40,24 @@
> >>   #define at91_adc_writel(st, reg, val) \
> >>          (writel_relaxed(val, st->reg_base + reg))
> >>
> >> +#define DRIVER_NAME            "at91_adc"
> >> +#define MAX_POS_BITS           12
> >> +
> >> +#define ZTHRESHOLD             9000
> >> +
> >>   struct at91_adc_caps {
> >> +       bool    has_12bits_xy;  /* true means use 12 bits. Otherwise 10 bits */
> >>          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;
> >>
> >>          if (iio_buffer_enabled(idev)) {
> >>                  disable_irq_nosync(irq);
> >> @@ -121,6 +153,115 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
> >>                  st->done = true;
> >>                  wake_up_interruptible(&st->wq_data_avail);
> >>          }
> >> +}
> >> +
> >> +static int at91_ts_sample(struct at91_adc_state *st)
> >> +{
> >> +       unsigned int xscale, yscale, reg, z1, z2;
> >> +       unsigned int x, y, pres, xpos, ypos;
> >> +       unsigned int rxp = 1;
> >> +       unsigned int factor = 1000;
> >> +       struct iio_dev *idev = iio_priv_to_dev(st);
> >> +
> >> +       unsigned int xyz_mask_bits = st->caps.has_12bits_xy ? 12 : 10;
> >> +       unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
> >> +
> >> +       /* calculate position */
> >> +       /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
> >> +       reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
> >> +       xpos = reg & xyz_mask;
> >> +       x = (xpos << MAX_POS_BITS) - xpos;
> >> +       xscale = (reg >> 16) & xyz_mask;
> >> +       if (xscale != 0)
> >> +               x /= xscale;
> >> +       else
> >> +               dev_err(&idev->dev, "xscale == 0!!!\n");
> >> +
> >> +       /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
> >> +       reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
> >> +       ypos = reg & xyz_mask;
> >> +       y = (ypos << MAX_POS_BITS) - ypos;
> >> +       yscale = (reg >> 16) & xyz_mask;
> >> +       if (yscale != 0)
> >> +               y /= yscale;
> >> +       else
> >> +               dev_err(&idev->dev, "yscale == 0!!!\n");
> >> +
> >> +       /* calculate the pressure */
> >> +       reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
> >> +       z1 = reg & xyz_mask;
> >> +       z2 = (reg >> 16) & xyz_mask;
> >> +
> >> +       if (z1 != 0)
> >> +               pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
> >> +                       / factor;
> >> +       else
> >> +               pres = ZTHRESHOLD;      /* no pen contacted */
> >> +
> >> +       dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
> >> +                               xpos, xscale, ypos, yscale, z1, z2, pres);
> >> +
> >> +       if (pres < ZTHRESHOLD) {
> >> +               dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
> >> +                                       x, y, pres / factor);
> >> +               input_report_abs(st->ts_input, ABS_X, x);
> >> +               input_report_abs(st->ts_input, ABS_Y, y);
> >> +               input_report_abs(st->ts_input, ABS_PRESSURE, pres);
> >> +               input_report_key(st->ts_input, BTN_TOUCH, 1);
> >> +               input_sync(st->ts_input);
> >> +       } else {
> >> +               dev_dbg(&idev->dev,
> >> +                               "pressure too low: not reporting\n");
> >> +       }
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +
> >> +static irqreturn_t at91_adc_interrupt(int irq, void *private)
> >> +{
> >> +       struct iio_dev *idev = private;
> >> +       struct at91_adc_state *st = iio_priv(idev);
> >> +       u32 status = at91_adc_readl(st, st->registers->status_register);
> >> +       const uint32_t ts_data_irq_mask =
> >> +               AT91_ADC_IER_XRDY |
> >> +               AT91_ADC_IER_YRDY |
> >> +               AT91_ADC_IER_PRDY;
> >> +
> >> +       if (status & st->registers->drdy_mask)
> >> +               handle_adc_eoc_trigger(irq, idev);
> >> +
> >> +       if (status & AT91_ADC_IER_PEN) {
> >> +               at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
> >> +               at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
> >> +                       ts_data_irq_mask);
> >> +               /* Set up period trigger for sampling */
> >> +               at91_adc_writel(st, st->registers->trigger_register,
> >> +                       AT91_ADC_TRGR_MOD_PERIOD_TRIG |
> >> +                       AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
> >> +       } else if (status & AT91_ADC_IER_NOPEN) {
> >> +               at91_adc_writel(st, st->registers->trigger_register, 0);
> >> +               at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
> >> +                       ts_data_irq_mask);
> >> +               at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
> >> +
> >> +               input_report_key(st->ts_input, BTN_TOUCH, 0);
> >> +               input_sync(st->ts_input);
> >> +       } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
> >> +               /* Now all touchscreen data is ready */
> >> +
> >> +               if (status & AT91_ADC_ISR_PENS) {
> >> +                       /* validate data by pen contact */
> >> +                       at91_ts_sample(st);
> >> +               } else {
> >> +                       /* triggered by event that is no pen contact, just read
> >> +                        * them to clean the interrupt and discard all.
> >> +                        */
> >> +                       at91_adc_readl(st, AT91_ADC_TSXPOSR);
> >> +                       at91_adc_readl(st, AT91_ADC_TSYPOSR);
> >> +                       at91_adc_readl(st, AT91_ADC_TSPRESSR);
> >> +               }
> >> +       }
> >>
> >>          return IRQ_HANDLED;
> >>   }
> >> @@ -130,6 +271,16 @@ static int at91_adc_channel_init(struct iio_dev *idev)
> >>          struct at91_adc_state *st = iio_priv(idev);
> >>          struct iio_chan_spec *chan_array, *timestamp;
> >>          int bit, idx = 0;
> >> +       unsigned long rsvd_mask = 0;
> >> +
> >> +       /* If touchscreen is enable, then reserve the adc channels */
> >> +       if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
> >> +               rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
> >> +       else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
> >> +               rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
> >> +
> >> +       /* set up the channel mask to reserve touchscreen channels */
> >> +       st->channels_mask &= ~rsvd_mask;
> >>
> >>          idev->num_channels = bitmap_weight(&st->channels_mask,
> >>                                             st->num_channels) + 1;
> >> @@ -561,6 +712,57 @@ static int at91_adc_probe_dt(struct at91_adc_state *st,
> >>                  i++;
> >>          }
> >>
> >> +       /* Check if touchscreen is enabled in DT. */
> >> +       ret = of_property_read_u32(node, "atmel,adc-touchscreen-wires", &prop);
> >> +       if (ret)
> >> +               dev_info(&idev->dev, "Touchscreen not enabled.\n");
> >> +       else if (prop == 4)
> >> +               st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_4WIRE;
> >> +       else if (prop == 5)
> >> +               st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_5WIRE;
> >> +       else
> >> +               dev_warn(&idev->dev, "Unsupported number of touchscreen wires (%d)\n",
> >> +                               prop);
> >> +
> >> +       if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_NONE)
> >> +               return 0;
> >> +
> >> +       /* Touch screen is enabled, so check touch screen dt parameters */
> >> +       if (of_property_read_u32(node, "atmel,adc-ts-filter-average", &prop)) {
> >> +               dev_err(&idev->dev, "Missing atmel,adc-ts-filtering-average property in the DT.\n");
> >> +               ret = -EINVAL;
> >> +               goto error_ret;
> >> +       }
> >> +       st->ts_filter_average = prop;
> >> +       if (st->ts_filter_average > 3) {
> >> +               dev_err(&idev->dev, "Invalid atmel,adc-ts-filtering-average property in the DT.\n");
> >> +               ret = -EINVAL;
> >> +               goto error_ret;
> >> +       }
> >> +
> >> +       prop = 0;
> >> +       of_property_read_u32(node, "atmel,adc-ts-pendet-debounce", &prop);
> >> +       st->ts_pen_detect_debounce = prop;
> >> +
> >> +       /* default sample period is 2ms. The real touch sample period should be
> >> +        * this period * TSFREQ.
> >> +        */
> >> +       prop = 2000;
> >> +       of_property_read_u32(node, "atmel,adc-ts-sample-period-time", &prop);
> >> +       st->ts_sample_period_time = prop;
> >> +
> >> +       if (of_property_read_u32(node, "atmel,adc-ts-pendet-sensitivity", &prop)) {
> >> +               dev_err(&idev->dev, "Missing atmel,adc-ts-pendet-sensitivity property in the DT.\n");
> >> +               ret = -EINVAL;
> >> +               goto error_ret;
> >> +       }
> >> +       st->ts_pen_detect_sensitivity = prop;
> >> +       if (st->ts_pen_detect_sensitivity > 3) {
> >> +               dev_err(&idev->dev, "Invalid atmel,adc-ts-pendet-sensitivity property in the DT.\n");
> >> +               ret = -EINVAL;
> >> +               goto error_ret;
> >> +       }
> >> +
> >>          return 0;
> >>
> >>   error_ret:
> >> @@ -592,6 +794,114 @@ static const struct iio_info at91_adc_info = {
> >>          .read_raw = &at91_adc_read_raw,
> >>   };
> >>
> >> +/* Touchscreen related functions */
> >> +static int atmel_ts_open(struct input_dev *dev)
> >> +{
> >> +       struct at91_adc_state *st = input_get_drvdata(dev);
> >> +
> >> +       at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
> >> +       return 0;
> >> +}
> >> +
> >> +static void atmel_ts_close(struct input_dev *dev)
> >> +{
> >> +       struct at91_adc_state *st = input_get_drvdata(dev);
> >> +
> >> +       at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
> >> +}
> >> +
> >> +static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
> >> +{
> >> +       u32 reg = 0, pendbc;
> >> +       int i = 0;
> >> +
> >> +       if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
> >> +               reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
> >> +       else
> >> +               reg = AT91_ADC_TSMR_TSMODE_5WIRE;
> >> +
> >> +       /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
> >> +        * pen detect noise.
> >> +        * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
> >> +        */
> >> +       pendbc = round_up(st->ts_pen_detect_debounce * adc_clk_khz / 1000, 1);
> >> +
> >> +       while (pendbc >> ++i)
> >> +               ;       /* Empty! Find the shift offset */
> >> +       if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1))))
> >> +               pendbc = i;
> >> +       else
> >> +               pendbc = i - 1;
> >> +
> >> +       if (st->caps.has_tsmr) {
> >> +               reg |= AT91_ADC_TSMR_TSAV_(st->ts_filter_average)
> >> +                               & AT91_ADC_TSMR_TSAV;
> >> +               reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC;
> >> +               reg |= AT91_ADC_TSMR_NOTSDMA;
> >> +               reg |= AT91_ADC_TSMR_PENDET_ENA;
> >> +               reg |= 0x03 << 8;       /* TSFREQ, need bigger than TSAV */
> >> +
> >> +               at91_adc_writel(st, AT91_ADC_TSMR, reg);
> >> +       } else {
> >> +               /* TODO: for 9g45 which has no TSMR */
> >> +       }
> >> +
> >> +       /* Change adc internal resistor value for better pen detection,
> >> +        * default value is 100 kOhm.
> >> +        * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
> >> +        * option only available on ES2 and higher
> >> +        */
> >> +       at91_adc_writel(st, AT91_ADC_ACR, st->ts_pen_detect_sensitivity
> >> +                       & AT91_ADC_ACR_PENDETSENS);
> >> +
> >> +       /* Sample Peroid Time = (TRGPER + 1) / ADCClock */
> >> +       st->ts_sample_period_val = round_up((st->ts_sample_period_time *
> >> +                       adc_clk_khz / 1000) - 1, 1);
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static int at91_ts_register(struct at91_adc_state *st)
> >> +{
> >> +       struct input_dev *input;
> >> +       struct iio_dev *idev = iio_priv_to_dev(st);
> >> +       int ret;
> >> +
> >> +       input = input_allocate_device();
> >> +       if (!input) {
> >> +               dev_err(&idev->dev, "Failed to allocate TS device!\n");
> >> +               return -ENOMEM;
> >> +       }
> >> +
> >> +       input->name = DRIVER_NAME;
> >> +       input->id.bustype = BUS_HOST;
> >> +       input->dev.parent = idev->dev.parent;
> >> +       input->open = atmel_ts_open;
> >> +       input->close = atmel_ts_close;
> >> +
> >> +       __set_bit(EV_ABS, input->evbit);
> >> +       __set_bit(EV_KEY, input->evbit);
> >> +       __set_bit(BTN_TOUCH, input->keybit);
> >> +       input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, 0, 0);
> >> +       input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0);
> >> +       input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
> >> +
> >> +       st->ts_input = input;
> >> +       input_set_drvdata(input, st);
> >> +
> >> +       ret = input_register_device(input);
> >> +       if (ret)
> >> +               input_free_device(st->ts_input);
> >> +
> >> +       return ret;
> >> +}
> >> +
> >> +static void at91_ts_unregister(struct at91_adc_state *st)
> >> +{
> >> +       input_unregister_device(st->ts_input);
> >> +       input_free_device(st->ts_input);
> >> +}
> >> +
> >>   /*
> >>    * Since atmel adc support different ip for touchscreen mode. Through the
> >>    * IP check, we will know the touchscreen capbilities.
> >> @@ -610,6 +920,7 @@ static void atmel_adc_get_cap(struct at91_adc_state *st)
> >>          /* keep only major version number */
> >>          switch (version & 0xf00) {
> >>          case 0x500:     /* SAMA5D3 */
> >> +               st->caps.has_12bits_xy = 1;
> >>          case 0x400:     /* AT91SAM9X5/9N12 */
> >>                  st->caps.has_tsmr = 1;
> >>                  st->caps.mr_startup_mask = AT91_ADC_STARTUP;
> >> @@ -683,7 +994,7 @@ static int at91_adc_probe(struct platform_device *pdev)
> >>          at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
> >>          at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
> >>          ret = request_irq(st->irq,
> >> -                         at91_adc_eoc_trigger,
> >> +                         at91_adc_interrupt,
> >>                            0,
> >>                            pdev->dev.driver->name,
> >>                            idev);
> >> @@ -731,6 +1042,10 @@ static int at91_adc_probe(struct platform_device *pdev)
> >>          adc_clk = st->adc_clk_rate ?
> >>                  st->adc_clk_rate : clk_get_rate(st->adc_clk);
> >>          adc_clk_khz = adc_clk / 1000;
> >> +
> >> +       dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
> >> +               mstrclk, adc_clk);
> >> +
> >>          prsc = (mstrclk / (2 * adc_clk)) - 1;
> >>
> >>          if (!st->startup_time) {
> >> @@ -799,30 +1114,52 @@ static int at91_adc_probe(struct platform_device *pdev)
> >>          init_waitqueue_head(&st->wq_data_avail);
> >>          mutex_init(&st->lock);
> >>
> >> -       ret = at91_adc_buffer_init(idev);
> >> -       if (ret < 0) {
> >> -               dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
> >> -               goto error_disable_adc_clk;
> >> -       }
> >> +       /*
> >> +        * Since touch screen will set trigger register as period trigger. So
> >> +        * when touch screen is enabled, then we have to disable hardware
> >> +        * trigger for classic adc.
> >> +        */
> >> +       if (!st->touchscreen_type) {
> >> +               ret = at91_adc_buffer_init(idev);
> >> +               if (ret < 0) {
> >> +                       dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
> >> +                       goto error_disable_adc_clk;
> >> +               }
> >>
> >> -       ret = at91_adc_trigger_init(idev);
> >> -       if (ret < 0) {
> >> -               dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
> >> -               goto error_unregister_buffer;
> >> +               ret = at91_adc_trigger_init(idev);
> >> +               if (ret < 0) {
> >> +                       dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
> >> +                       at91_adc_buffer_remove(idev);
> >> +                       goto error_disable_adc_clk;
> >> +               }
> >> +       } else {
> >> +               if (!st->caps.has_tsmr) {
> >> +                       dev_err(&pdev->dev, "We don't support non-TSMR adc\n");
> >> +                       goto error_disable_adc_clk;
> >> +               }
> >> +
> >> +               ret = at91_ts_register(st);
> >> +               if (ret)
> >> +                       goto error_disable_adc_clk;
> >> +
> >> +               at91_ts_hw_init(st, adc_clk_khz);
> >>          }
> >>
> >>          ret = iio_device_register(idev);
> >>          if (ret < 0) {
> >>                  dev_err(&pdev->dev, "Couldn't register the device.\n");
> >> -               goto error_remove_triggers;
> >> +               goto error_iio_device_register;
> >>          }
> >>
> >>          return 0;
> >>
> >> -error_remove_triggers:
> >> -       at91_adc_trigger_remove(idev);
> >> -error_unregister_buffer:
> >> -       at91_adc_buffer_remove(idev);
> >> +error_iio_device_register:
> >> +       if (!st->touchscreen_type) {
> >> +               at91_adc_trigger_remove(idev);
> >> +               at91_adc_buffer_remove(idev);
> >> +       } else {
> >> +               at91_ts_unregister(st);
> >> +       }
> >>   error_disable_adc_clk:
> >>          clk_disable_unprepare(st->adc_clk);
> >>   error_disable_clk:
> >> @@ -841,8 +1178,12 @@ static int at91_adc_remove(struct platform_device *pdev)
> >>          struct at91_adc_state *st = iio_priv(idev);
> >>
> >>          iio_device_unregister(idev);
> >> -       at91_adc_trigger_remove(idev);
> >> -       at91_adc_buffer_remove(idev);
> >> +       if (!st->touchscreen_type) {
> >> +               at91_adc_trigger_remove(idev);
> >> +               at91_adc_buffer_remove(idev);
> >> +       } else {
> >> +               at91_ts_unregister(st);
> >> +       }
> >>          clk_disable_unprepare(st->adc_clk);
> >>          clk_disable_unprepare(st->clk);
> >>          free_irq(st->irq, idev);
> >> @@ -861,7 +1202,7 @@ static struct platform_driver at91_adc_driver = {
> >>          .probe = at91_adc_probe,
> >>          .remove = at91_adc_remove,
> >>          .driver = {
> >> -                  .name = "at91_adc",
> >> +                  .name = DRIVER_NAME,
> >>                     .of_match_table = of_match_ptr(at91_adc_dt_ids),
> >>          },
> >>   };
> >> --
> >> 1.7.10
> >>
> >>
> >> _______________________________________________
> >> linux-arm-kernel mailing list
> >> linux-arm-kernel at lists.infradead.org
> >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >>
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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