[PATCH 03/21] input: ti_am33x_tsc: Order of TSC wires, made configurable

From: Sebastian Andrzej Siewior
Date: Wed Jun 12 2013 - 13:00:01 EST


From: "Patil, Rachna" <rachna@xxxxxx>

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@xxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
drivers/input/touchscreen/ti_am335x_tsc.c | 102 ++++++++++++++++++++++++-----
include/linux/input/ti_am335x_tsc.h | 12 ++++
include/linux/mfd/ti_am335x_tscadc.h | 3 -
3 files changed, 98 insertions(+), 19 deletions(-)

diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 23d6a4d..2bdd66c 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c
@@ -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;
@@ -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)
@@ -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;
@@ -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;
}

@@ -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;
}

@@ -108,9 +170,9 @@ 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);
@@ -118,13 +180,14 @@ static void titsc_step_config(struct titsc *ts_dev)
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);
@@ -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);
@@ -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);

diff --git a/include/linux/input/ti_am335x_tsc.h b/include/linux/input/ti_am335x_tsc.h
index 49269a2..6a66b4d 100644
--- a/include/linux/input/ti_am335x_tsc.h
+++ b/include/linux/input/ti_am335x_tsc.h
@@ -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
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 4258627..e36ae41 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -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)
@@ -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)
--
1.7.10.4

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