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: Brad Griffis <bgriffis@ti.com>
[vigneshr@ti.com: Ported the patch from v3.12 to v3.19rc1]
Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index b730864..adba232 100644 (file)
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -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;

diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 004f134..dfbb9fe 100644 (file)
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -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;
                }
        }
 }