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

From: [email-masked] (Josh Wu)
Date: Thu, 25 Jul 2013 15:56:38 +0800

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 <[email-masked]>
>> Cc: Dmitry Torokhov <[email-masked]>
>> ---
>>   .../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.

>
>> +    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.

>
>> +  - 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.

>
>> +  - 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.
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?

>
> 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.

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
>>
>>
>> _______________________________________________
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>> linux-arm-kernel at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>