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Commit 3a59684c authored by Brad Griffis's avatar Brad Griffis Committed by Dmitry Torokhov
Browse files

Input: ti_am335x_tsc - interchange touchscreen and ADC steps 



This patch makes the initial changes required to workaround TSC-false
pen-up interrupts. It is required to implement these changes in order to
remove udelay in the TSC interrupt handler and false pen-up events.  The
charge step is to be executed immediately after sampling X+. Hence TSC is
made to use higher numbered steps (steps 5 to 16 for 5 co-ordinate
readouts, 4 wire TSC configuration) and ADC to use lower ones. Further X
co-ordinate readouts must be the last to be sampled, thus co-ordinates are
sampled in the order Y-Z-X.

Signed-off-by: default avatarBrad Griffis <bgriffis@ti.com>
[vigneshr@ti.com: Ported the patch from v3.12 to v3.19rc1]
Signed-off-by: default avatarVignesh R <vigneshr@ti.com>
Acked-by: default avatarJonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 448c7f38

drivers/iio/adc/ti_am335x_adc.c

+2 −3
Original line number Diff line number Diff line
@@ -86,19 +86,18 @@ static void tiadc_step_config(struct iio_dev *indio_dev) 
{

	struct tiadc_device *adc_dev = iio_priv(indio_dev);

	unsigned int stepconfig;

	int i, steps;

	int i, steps = 0;



	/*

	 * There are 16 configurable steps and 8 analog input

	 * lines available which are shared between Touchscreen and ADC.

	 *

	 * Steps backwards i.e. from 16 towards 0 are used by ADC

	 * Steps forwards i.e. from 0 towards 16 are used by ADC

	 * depending on number of input lines needed.

	 * Channel would represent which analog input

	 * needs to be given to ADC to digitalize data.

	 */



	steps = TOTAL_STEPS - adc_dev->channels;

	if (iio_buffer_enabled(indio_dev))

		stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1

					| STEPCONFIG_MODE_SWCNT;

drivers/input/touchscreen/ti_am335x_tsc.c

+24 −18
Original line number Diff line number Diff line
@@ -121,7 +121,7 @@ static void titsc_step_config(struct titsc *ts_dev) 
{

	unsigned int	config;

	int i;

	int end_step;

	int end_step, first_step, tsc_steps;

	u32 stepenable;



	config = STEPCONFIG_MODE_HWSYNC |
@@ -140,9 +140,11 @@ static void titsc_step_config(struct titsc *ts_dev) 
		break;

	}



	/* 1 … coordinate_readouts is for X */

	end_step = ts_dev->coordinate_readouts;

	for (i = 0; i < end_step; i++) {

	tsc_steps = ts_dev->coordinate_readouts * 2 + 2;

	first_step = TOTAL_STEPS - tsc_steps;

	/* Steps 16 to 16-coordinate_readouts is for X */

	end_step = first_step + tsc_steps;

	for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {

		titsc_writel(ts_dev, REG_STEPCONFIG(i), config);

		titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);

	}
@@ -164,9 +166,9 @@ static void titsc_step_config(struct titsc *ts_dev) 
		break;

	}



	/* coordinate_readouts … coordinate_readouts * 2 is for Y */

	end_step = ts_dev->coordinate_readouts * 2;

	for (i = ts_dev->coordinate_readouts; i < end_step; i++) {

	/* 1 ... coordinate_readouts is for Y */

	end_step = first_step + ts_dev->coordinate_readouts;

	for (i = first_step; i < end_step; i++) {

		titsc_writel(ts_dev, REG_STEPCONFIG(i), config);

		titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);

	}
@@ -179,7 +181,7 @@ static void titsc_step_config(struct titsc *ts_dev) 
	titsc_writel(ts_dev, REG_CHARGECONFIG, config);

	titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);



	/* coordinate_readouts * 2 … coordinate_readouts * 2 + 2 is for Z */

	/* coordinate_readouts + 1 ... coordinate_readouts + 2 is for Z */

	config = STEPCONFIG_MODE_HWSYNC |

			STEPCONFIG_AVG_16 | ts_dev->bit_yp |

			ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
@@ -194,8 +196,11 @@ static void titsc_step_config(struct titsc *ts_dev) 
	titsc_writel(ts_dev, REG_STEPDELAY(end_step),

			STEPCONFIG_OPENDLY);



	/* The steps1 … end and bit 0 for TS_Charge */

	stepenable = (1 << (end_step + 2)) - 1;

	/* The steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */

	stepenable = 1;

	for (i = 0; i < tsc_steps; i++)

		stepenable |= 1 << (first_step + i + 1);



	ts_dev->step_mask = stepenable;

	am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);

}
@@ -209,6 +214,7 @@ static void titsc_read_coordinates(struct titsc *ts_dev, 
	unsigned int read, diff;

	unsigned int i, channel;

	unsigned int creads = ts_dev->coordinate_readouts;

	unsigned int first_step = TOTAL_STEPS - (creads * 2 + 2);



	*z1 = *z2 = 0;

	if (fifocount % (creads * 2 + 2))
@@ -226,7 +232,7 @@ static void titsc_read_coordinates(struct titsc *ts_dev, 


		channel = (read & 0xf0000) >> 16;

		read &= 0xfff;

		if (channel < creads) {

		if (channel > first_step + creads + 2) {

			diff = abs(read - prev_val_x);

			if (diff < prev_diff_x) {

				prev_diff_x = diff;
@@ -234,19 +240,19 @@ static void titsc_read_coordinates(struct titsc *ts_dev, 
			}

			prev_val_x = read;



		} else if (channel < creads * 2) {

		} else if (channel == first_step + creads + 1) {

			*z1 = read;



		} else if (channel == first_step + creads + 2) {

			*z2 = read;



		} else if (channel > first_step) {

			diff = abs(read - prev_val_y);

			if (diff < prev_diff_y) {

				prev_diff_y = diff;

				*y = read;

			}

			prev_val_y = read;



		} else if (channel < creads * 2 + 1) {

			*z1 = read;



		} else if (channel < creads * 2 + 2) {

			*z2 = read;

		}

	}

}