static irqreturn_t titsc_irq(int irq, void *dev)
{
struct titsc *ts_dev = dev;
struct input_dev *input_dev = ts_dev->input;
unsigned int fsm, status, irqclr = 0;
unsigned int x = 0, y = 0;
unsigned int z1, z2, z;
status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
if (status & IRQENB_HW_PEN) {
ts_dev->pen_down = true;
irqclr |= IRQENB_HW_PEN;
pm_stay_awake(ts_dev->mfd_tscadc->dev);
}
if (status & IRQENB_PENUP) {
fsm = titsc_readl(ts_dev, REG_ADCFSM);
if (fsm == ADCFSM_STEPID) {
ts_dev->pen_down = false;
input_report_key(input_dev, BTN_TOUCH, 0);
input_report_abs(input_dev, ABS_PRESSURE, 0);
input_sync(input_dev);
pm_relax(ts_dev->mfd_tscadc->dev);
} else {
ts_dev->pen_down = true;
}
irqclr |= IRQENB_PENUP;
}
if (status & IRQENB_EOS)
irqclr |= IRQENB_EOS;
/*
* ADC and touchscreen share the IRQ line.
* FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
*/
if (status & IRQENB_FIFO0THRES) {
titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
/*
* Calculate pressure using formula
* Resistance(touch) = x plate resistance *
* x postion/4096 * ((z2 / z1) - 1)
*/
z = z1 - z2;
z *= x;
z *= ts_dev->x_plate_resistance;
z /= z2;
z = (z + 2047) >> 12;
if (z <= MAX_12BIT) {
input_report_abs(input_dev, ABS_X, x);
input_report_abs(input_dev, ABS_Y, y);
input_report_abs(input_dev, ABS_PRESSURE, z);
input_report_key(input_dev, BTN_TOUCH, 1);
input_sync(input_dev);
}
}
static void titsc_read_coordinates(struct titsc *ts_dev,
u32 *x, u32 *y, u32 *z1, u32 *z2)
{
unsigned int yvals[7], xvals[7];
unsigned int i, xsum = 0, ysum = 0;
unsigned int creads = ts_dev->coordinate_readouts;
for (i = 0; i < creads; i++) {
yvals[i] = titsc_readl(ts_dev, REG_FIFO0);
yvals[i] &= 0xfff;
}
*z1 = titsc_readl(ts_dev, REG_FIFO0);
*z1 &= 0xfff;
*z2 = titsc_readl(ts_dev, REG_FIFO0);
*z2 &= 0xfff;
for (i = 0; i < creads; i++) {
xvals[i] = titsc_readl(ts_dev, REG_FIFO0);
xvals[i] &= 0xfff;
}
/*
* If co-ordinates readouts is less than 4 then
* report the average. In case of 4 or more
* readouts, sort the co-ordinate samples, drop
* min and max values and report the average of
* remaining values.
*/
if (creads <= 3) {
for (i = 0; i < creads; i++) {
ysum += yvals[i];
xsum += xvals[i];
}
ysum /= creads;
xsum /= creads;
} else {
sort(yvals, creads, sizeof(unsigned int),
titsc_cmp_coord, NULL);
sort(xvals, creads, sizeof(unsigned int),
titsc_cmp_coord, NULL);
for (i = 1; i < creads - 1; i++) {
ysum += yvals[i];
xsum += xvals[i];
}
ysum /= creads - 2;
xsum /= creads - 2;
}
*y = ysum;
*x = xsum;
}
static void titsc_read_coordinates(struct titsc *ts_dev,
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
* coordinate could be. This is done by taking a previous
* coordinate and subtracting it form current one. Further the
* 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; i++) {
read = titsc_readl(ts_dev, REG_FIFO0);
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;
} 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;
}
}
}
static irqreturn_t titsc_irq(int irq, void *dev)
{
struct titsc *ts_dev = dev;
struct input_dev *input_dev = ts_dev->input;
unsigned int status, irqclr = 0;
unsigned int x = 0, y = 0;
unsigned int z1, z2, z;
unsigned int fsm;
status = titsc_readl(ts_dev, REG_IRQSTATUS);
if (status & IRQENB_FIFO0THRES) {
titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
/*
* Calculate pressure using formula
* Resistance(touch) = x plate resistance *
* x postion/4096 * ((z2 / z1) - 1)
*/
z = z1 - z2;
z *= x;
z *= ts_dev->x_plate_resistance;
z /= z2;
z = (z + 2047) >> 12;
if (z <= MAX_12BIT) {
input_report_abs(input_dev, ABS_X, x);
input_report_abs(input_dev, ABS_Y, y);
input_report_abs(input_dev, ABS_PRESSURE, z);
input_report_key(input_dev, BTN_TOUCH, 1);
input_sync(input_dev);
}
}
static void titsc_read_coordinates(struct titsc *ts_dev,
unsigned int *x, unsigned int *y)
{
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;
/*
* Delta filter is used to remove large variations in sampled
* values from ADC. The filter tries to predict where the next
* coordinate could be. This is done by taking a previous
* coordinate and subtracting it form current one. Further the
* 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++) {
read = titsc_readl(ts_dev, REG_FIFO0);
channel = read & 0xf0000;
channel = channel >> 0x10;
if ((channel >= 0) && (channel < ts_dev->steps_to_configure)) {
read &= 0xfff;
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->steps_to_configure) &&
(channel < (2 * ts_dev->steps_to_configure - 1))) {
read &= 0xfff;
diff = abs(read - prev_val_y);
if (diff < prev_diff_y) {
prev_diff_y = diff;
*y = read;
}
prev_val_y = read;
}
}
}
static void titsc_step_config(struct titsc *ts_dev)
{
unsigned int config;
int i;
int end_step, first_step, tsc_steps;
u32 stepenable;
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_xp;
switch (ts_dev->wires) {
case 4:
config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
break;
case 5:
config |= ts_dev->bit_yn |
STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
ts_dev->bit_yp;
break;
case 8:
config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
break;
}
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);
}
config = 0;
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_yn |
STEPCONFIG_INM_ADCREFM;
switch (ts_dev->wires) {
case 4:
config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
break;
case 5:
config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
ts_dev->bit_xn | ts_dev->bit_yp;
break;
case 8:
config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
break;
}
/* 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);
}
/* Make CHARGECONFIG same as IDLECONFIG */
config = titsc_readl(ts_dev, REG_IDLECONFIG);
titsc_writel(ts_dev, REG_CHARGECONFIG, config);
titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay);
/* 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 |
STEPCONFIG_INP(ts_dev->inp_xp);
titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
titsc_writel(ts_dev, REG_STEPDELAY(end_step),
STEPCONFIG_OPENDLY);
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 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);
}
