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path: root/drivers/input/touchscreen/ti_am335x_tsc.c
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Diffstat (limited to 'drivers/input/touchscreen/ti_am335x_tsc.c')
-rw-r--r--drivers/input/touchscreen/ti_am335x_tsc.c78
1 files changed, 41 insertions, 37 deletions
diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index ff3215ddf9f..1bceb2591fc 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -120,11 +120,9 @@ static int titsc_config_wires(struct titsc *ts_dev)
static void titsc_step_config(struct titsc *ts_dev)
{
unsigned int config;
- unsigned int stepenable = 0;
- int i, total_steps;
-
- /* Configure the Step registers */
- total_steps = 2 * ts_dev->coordinate_readouts;
+ int i;
+ int end_step;
+ u32 stepenable;
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_xp;
@@ -142,7 +140,9 @@ static void titsc_step_config(struct titsc *ts_dev)
break;
}
- for (i = 1; i <= ts_dev->coordinate_readouts; i++) {
+ /* 1 … coordinate_readouts is for X */
+ end_step = ts_dev->coordinate_readouts;
+ for (i = 0; i < end_step; i++) {
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
}
@@ -150,7 +150,7 @@ static void titsc_step_config(struct titsc *ts_dev)
config = 0;
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_yn |
- STEPCONFIG_INM_ADCREFM | STEPCONFIG_FIFO1;
+ STEPCONFIG_INM_ADCREFM;
switch (ts_dev->wires) {
case 4:
config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
@@ -164,12 +164,13 @@ static void titsc_step_config(struct titsc *ts_dev)
break;
}
- for (i = (ts_dev->coordinate_readouts + 1); i <= total_steps; i++) {
+ /* 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++) {
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
}
- config = 0;
/* Charge step configuration */
config = ts_dev->bit_xp | ts_dev->bit_yn |
STEPCHARGE_RFP_XPUL | STEPCHARGE_RFM_XNUR |
@@ -178,35 +179,39 @@ static void titsc_step_config(struct titsc *ts_dev)
titsc_writel(ts_dev, REG_CHARGECONFIG, config);
titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);
- config = 0;
- /* Configure to calculate pressure */
+ /* coordinate_readouts * 2 … coordinate_readouts * 2 + 2 is for Z */
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_yp |
ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
STEPCONFIG_INP(ts_dev->inp_xp);
- titsc_writel(ts_dev, REG_STEPCONFIG(total_steps + 1), config);
- titsc_writel(ts_dev, REG_STEPDELAY(total_steps + 1),
+ titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
+ titsc_writel(ts_dev, REG_STEPDELAY(end_step),
STEPCONFIG_OPENDLY);
- config |= STEPCONFIG_INP(ts_dev->inp_yn) | STEPCONFIG_FIFO1;
- titsc_writel(ts_dev, REG_STEPCONFIG(total_steps + 2), config);
- titsc_writel(ts_dev, REG_STEPDELAY(total_steps + 2),
+ end_step++;
+ config |= STEPCONFIG_INP(ts_dev->inp_yn);
+ titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
+ titsc_writel(ts_dev, REG_STEPDELAY(end_step),
STEPCONFIG_OPENDLY);
/* The steps1 … end and bit 0 for TS_Charge */
- stepenable = (1 << (total_steps + 2)) - 1;
+ stepenable = (1 << (end_step + 2)) - 1;
am335x_tsc_se_set(ts_dev->mfd_tscadc, stepenable);
}
static void titsc_read_coordinates(struct titsc *ts_dev,
- unsigned int *x, unsigned int *y)
+ u32 *x, u32 *y, u32 *z1, u32 *z2)
{
unsigned int fifocount = titsc_readl(ts_dev, REG_FIFO0CNT);
unsigned int prev_val_x = ~0, prev_val_y = ~0;
unsigned int prev_diff_x = ~0, prev_diff_y = ~0;
unsigned int read, diff;
unsigned int i, channel;
+ unsigned int creads = ts_dev->coordinate_readouts;
+ *z1 = *z2 = 0;
+ if (fifocount % (creads * 2 + 2))
+ fifocount -= fifocount % (creads * 2 + 2);
/*
* Delta filter is used to remove large variations in sampled
* values from ADC. The filter tries to predict where the next
@@ -215,32 +220,32 @@ static void titsc_read_coordinates(struct titsc *ts_dev,
* algorithm compares the difference with that of a present value,
* if true the value is reported to the sub system.
*/
- for (i = 0; i < fifocount - 1; i++) {
+ for (i = 0; i < fifocount; i++) {
read = titsc_readl(ts_dev, REG_FIFO0);
- channel = read & 0xf0000;
- channel = channel >> 0x10;
- if ((channel >= 0) && (channel < ts_dev->coordinate_readouts)) {
- read &= 0xfff;
+
+ channel = (read & 0xf0000) >> 16;
+ read &= 0xfff;
+ if (channel < creads) {
diff = abs(read - prev_val_x);
if (diff < prev_diff_x) {
prev_diff_x = diff;
*x = read;
}
prev_val_x = read;
- }
- read = titsc_readl(ts_dev, REG_FIFO1);
- channel = read & 0xf0000;
- channel = channel >> 0x10;
- if ((channel >= ts_dev->coordinate_readouts) &&
- (channel < (2 * ts_dev->coordinate_readouts - 1))) {
- read &= 0xfff;
+ } else if (channel < creads * 2) {
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;
}
}
}
@@ -256,10 +261,8 @@ static irqreturn_t titsc_irq(int irq, void *dev)
status = titsc_readl(ts_dev, REG_IRQSTATUS);
if (status & IRQENB_FIFO0THRES) {
- titsc_read_coordinates(ts_dev, &x, &y);
- z1 = titsc_readl(ts_dev, REG_FIFO0) & 0xfff;
- z2 = titsc_readl(ts_dev, REG_FIFO1) & 0xfff;
+ titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
/*
@@ -267,10 +270,10 @@ static irqreturn_t titsc_irq(int irq, void *dev)
* Resistance(touch) = x plate resistance *
* x postion/4096 * ((z2 / z1) - 1)
*/
- z = z2 - z1;
+ z = z1 - z2;
z *= x;
z *= ts_dev->x_plate_resistance;
- z /= z1;
+ z /= z2;
z = (z + 2047) >> 12;
if (z <= MAX_12BIT) {
@@ -391,7 +394,8 @@ static int titsc_probe(struct platform_device *pdev)
goto err_free_irq;
}
titsc_step_config(ts_dev);
- titsc_writel(ts_dev, REG_FIFO0THR, ts_dev->coordinate_readouts);
+ titsc_writel(ts_dev, REG_FIFO0THR,
+ ts_dev->coordinate_readouts * 2 + 2 - 1);
input_dev->name = "ti-tsc";
input_dev->dev.parent = &pdev->dev;
@@ -468,7 +472,7 @@ static int titsc_resume(struct device *dev)
}
titsc_step_config(ts_dev);
titsc_writel(ts_dev, REG_FIFO0THR,
- ts_dev->coordinate_readouts);
+ ts_dev->coordinate_readouts * 2 + 2 - 1);
return 0;
}