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input: ti_am33x_tsc: Order of TSC wires, made configurable
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The current driver expected touchscreen input
wires(XP,XN,YP,YN) to be connected in a particular order.
Making changes to accept this as platform data.

Sebastian reworked the original patch and removed a lot of the not
required pieces.

Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Patil, Rachna authored and Sebastian Andrzej Siewior committed Jun 12, 2013
1 parent abeccee commit bb76dc0
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Showing 3 changed files with 98 additions and 19 deletions.
102 changes: 86 additions & 16 deletions drivers/input/touchscreen/ti_am335x_tsc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -33,6 +33,13 @@
#define SEQ_SETTLE 275
#define MAX_12BIT ((1 << 12) - 1)

static const int config_pins[] = {
STEPCONFIG_XPP,
STEPCONFIG_XNN,
STEPCONFIG_YPP,
STEPCONFIG_YNN,
};

struct titsc {
struct input_dev *input;
struct ti_tscadc_dev *mfd_tscadc;
Expand All @@ -41,6 +48,9 @@ struct titsc {
unsigned int x_plate_resistance;
bool pen_down;
int steps_to_configure;
u32 config_inp[4];
u32 bit_xp, bit_xn, bit_yp, bit_yn;
u32 inp_xp, inp_xn, inp_yp, inp_yn;
};

static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
Expand All @@ -54,6 +64,58 @@ static void titsc_writel(struct titsc *tsc, unsigned int reg,
writel(val, tsc->mfd_tscadc->tscadc_base + reg);
}

static int titsc_config_wires(struct titsc *ts_dev)
{
u32 analog_line[4];
u32 wire_order[4];
int i, bit_cfg;

for (i = 0; i < 4; i++) {
/*
* Get the order in which TSC wires are attached
* w.r.t. each of the analog input lines on the EVM.
*/
analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
wire_order[i] = ts_dev->config_inp[i] & 0x0F;
if (WARN_ON(analog_line[i] > 7))
return -EINVAL;
if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
return -EINVAL;
}

for (i = 0; i < 4; i++) {
int an_line;
int wi_order;

an_line = analog_line[i];
wi_order = wire_order[i];
bit_cfg = config_pins[wi_order];
if (bit_cfg == 0)
return -EINVAL;
switch (wi_order) {
case 0:
ts_dev->bit_xp = bit_cfg;
ts_dev->inp_xp = an_line;
break;

case 1:
ts_dev->bit_xn = bit_cfg;
ts_dev->inp_xn = an_line;
break;

case 2:
ts_dev->bit_yp = bit_cfg;
ts_dev->inp_yp = an_line;
break;
case 3:
ts_dev->bit_yn = bit_cfg;
ts_dev->inp_yn = an_line;
break;
}
}
return 0;
}

static void titsc_step_config(struct titsc *ts_dev)
{
unsigned int config;
Expand All @@ -64,18 +126,18 @@ static void titsc_step_config(struct titsc *ts_dev)
total_steps = 2 * ts_dev->steps_to_configure;

config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | STEPCONFIG_XPP;
STEPCONFIG_AVG_16 | ts_dev->bit_xp;
switch (ts_dev->wires) {
case 4:
config |= STEPCONFIG_INP_AN2 | STEPCONFIG_XNN;
config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
break;
case 5:
config |= STEPCONFIG_YNN |
STEPCONFIG_INP_AN4 | STEPCONFIG_XNN |
STEPCONFIG_YPP;
config |= ts_dev->bit_yn |
STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
ts_dev->bit_yp;
break;
case 8:
config |= STEPCONFIG_INP_AN2 | STEPCONFIG_XNN;
config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
break;
}

Expand All @@ -86,18 +148,18 @@ static void titsc_step_config(struct titsc *ts_dev)

config = 0;
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | STEPCONFIG_YNN |
STEPCONFIG_AVG_16 | ts_dev->bit_yn |
STEPCONFIG_INM_ADCREFM | STEPCONFIG_FIFO1;
switch (ts_dev->wires) {
case 4:
config |= STEPCONFIG_YPP;
config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
break;
case 5:
config |= STEPCONFIG_XPP | STEPCONFIG_INP_AN4 |
STEPCONFIG_XNP | STEPCONFIG_YPN;
config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
ts_dev->bit_xn | ts_dev->bit_yp;
break;
case 8:
config |= STEPCONFIG_YPP;
config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
break;
}

Expand All @@ -108,23 +170,24 @@ static void titsc_step_config(struct titsc *ts_dev)

config = 0;
/* Charge step configuration */
config = STEPCONFIG_XPP | STEPCONFIG_YNN |
config = ts_dev->bit_xp | ts_dev->bit_yn |
STEPCHARGE_RFP_XPUL | STEPCHARGE_RFM_XNUR |
STEPCHARGE_INM_AN1 | STEPCHARGE_INP_AN1;
STEPCHARGE_INM_AN1 | STEPCHARGE_INP(ts_dev->inp_yp);

titsc_writel(ts_dev, REG_CHARGECONFIG, config);
titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);

config = 0;
/* Configure to calculate pressure */
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | STEPCONFIG_YPP |
STEPCONFIG_XNN | STEPCONFIG_INM_ADCREFM;
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),
STEPCONFIG_OPENDLY);

config |= STEPCONFIG_INP_AN3 | STEPCONFIG_FIFO1;
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),
STEPCONFIG_OPENDLY);
Expand Down Expand Up @@ -292,6 +355,8 @@ static int titsc_probe(struct platform_device *pdev)
ts_dev->wires = pdata->tsc_init->wires;
ts_dev->x_plate_resistance = pdata->tsc_init->x_plate_resistance;
ts_dev->steps_to_configure = pdata->tsc_init->steps_to_configure;
memcpy(ts_dev->config_inp, pdata->tsc_init->wire_config,
sizeof(pdata->tsc_init->wire_config));

err = request_irq(ts_dev->irq, titsc_irq,
0, pdev->dev.driver->name, ts_dev);
Expand All @@ -301,6 +366,11 @@ static int titsc_probe(struct platform_device *pdev)
}

titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
err = titsc_config_wires(ts_dev);
if (err) {
dev_err(&pdev->dev, "wrong i/p wire configuration\n");
goto err_free_irq;
}
titsc_step_config(ts_dev);
titsc_writel(ts_dev, REG_FIFO0THR, ts_dev->steps_to_configure);

Expand Down
12 changes: 12 additions & 0 deletions include/linux/input/ti_am335x_tsc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12,12 +12,24 @@
* A step configured to read a single
* co-ordinate value, can be applied
* more number of times for better results.
* @wire_config: Different EVM's could have a different order
* for connecting wires on touchscreen.
* We need to provide an 8 bit number where in
* the 1st four bits represent the analog lines
* and the next 4 bits represent positive/
* negative terminal on that input line.
* Notations to represent the input lines and
* terminals resoectively is as follows:
* AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.
* XP = 0, XN = 1, YP = 2, YN = 3.
*
*/

struct tsc_data {
int wires;
int x_plate_resistance;
int steps_to_configure;
int wire_config[10];
};

#endif
3 changes: 0 additions & 3 deletions include/linux/mfd/ti_am335x_tscadc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -71,8 +71,6 @@
#define STEPCONFIG_INM_ADCREFM STEPCONFIG_INM(8)
#define STEPCONFIG_INP_MASK (0xF << 19)
#define STEPCONFIG_INP(val) ((val) << 19)
#define STEPCONFIG_INP_AN2 STEPCONFIG_INP(2)
#define STEPCONFIG_INP_AN3 STEPCONFIG_INP(3)
#define STEPCONFIG_INP_AN4 STEPCONFIG_INP(4)
#define STEPCONFIG_INP_ADCREFM STEPCONFIG_INP(8)
#define STEPCONFIG_FIFO1 BIT(26)
Expand All @@ -94,7 +92,6 @@
#define STEPCHARGE_INM_AN1 STEPCHARGE_INM(1)
#define STEPCHARGE_INP_MASK (0xF << 19)
#define STEPCHARGE_INP(val) ((val) << 19)
#define STEPCHARGE_INP_AN1 STEPCHARGE_INP(1)
#define STEPCHARGE_RFM_MASK (3 << 23)
#define STEPCHARGE_RFM(val) ((val) << 23)
#define STEPCHARGE_RFM_XNUR STEPCHARGE_RFM(1)
Expand Down

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