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Commit 0396310b authored by Patil, Rachna's avatar Patil, Rachna Committed by Sebastian Andrzej Siewior
Browse files

input: ti_am33x_tsc: Add DT support 



This patch adds DT support to touch driver. It also provides a binding
document which is used by the MFD and IIO part of the device.
This patch also renames steps_to_configure to coordinate_readouts
because the original name misleads the purpose of the variable.

Signed-off-by: default avatarPantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: default avatarPatil, Rachna <rachna@ti.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
parent af9c2fe3

Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt

0 → 100644
+44 −0
Original line number Diff line number Diff line 
* TI - TSC ADC (Touschscreen and analog digital converter)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



Required properties:

- child "tsc"

	ti,wires: Wires refer to application modes i.e. 4/5/8 wire touchscreen

		  support on the platform.

	ti,x-plate-resistance: X plate resistance

	ti,coordiante-readouts: The sequencer supports a total of 16

				programmable steps each step is used to

				read a single coordinate. A single

                                readout is enough but multiple reads can

				increase the quality.

				A value of 5 means, 5 reads for X, 5 for

				Y and 2 for Z (always). This utilises 12

				of the 16 software steps available. The

				remaining 4 can be used by the ADC.

	ti,wire-config: Different boards 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.

- child "adc"

	ti,adc-channels: List of analog inputs available for ADC.

			 AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7.



Example:

	tscadc: tscadc@44e0d000 {

		compatible = "ti,am3359-tscadc";

		tsc {

			ti,wires = <4>;

			ti,x-plate-resistance = <200>;

			ti,coordiante-readouts = <5>;

			ti,wire-config = <0x00 0x11 0x22 0x33>;

		};



		adc {

			ti,adc-channels = <4 5 6 7>;

		};

	}

drivers/input/touchscreen/ti_am335x_tsc.c

+82 −23
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ 
#include <linux/io.h>

#include <linux/input/ti_am335x_tsc.h>

#include <linux/delay.h>

#include <linux/of.h>

#include <linux/of_device.h>



#include <linux/mfd/ti_am335x_tscadc.h>
@@ -47,7 +49,7 @@ struct titsc { 
	unsigned int		wires;

	unsigned int		x_plate_resistance;

	bool			pen_down;

	int			steps_to_configure;

	int			coordinate_readouts;

	u32			config_inp[4];

	u32			bit_xp, bit_xn, bit_yp, bit_yn;

	u32			inp_xp, inp_xn, inp_yp, inp_yn;
@@ -123,7 +125,7 @@ static void titsc_step_config(struct titsc *ts_dev) 
	int i, total_steps;



	/* Configure the Step registers */

	total_steps = 2 * ts_dev->steps_to_configure;

	total_steps = 2 * ts_dev->coordinate_readouts;



	config = STEPCONFIG_MODE_HWSYNC |

			STEPCONFIG_AVG_16 | ts_dev->bit_xp;
@@ -141,7 +143,7 @@ static void titsc_step_config(struct titsc *ts_dev) 
		break;

	}



	for (i = 1; i <= ts_dev->steps_to_configure; i++) {

	for (i = 1; i <= ts_dev->coordinate_readouts; i++) {

		titsc_writel(ts_dev, REG_STEPCONFIG(i), config);

		titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);

	}
@@ -163,7 +165,7 @@ static void titsc_step_config(struct titsc *ts_dev) 
		break;

	}



	for (i = (ts_dev->steps_to_configure + 1); i <= total_steps; i++) {

	for (i = (ts_dev->coordinate_readouts + 1); i <= total_steps; i++) {

		titsc_writel(ts_dev, REG_STEPCONFIG(i), config);

		titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);

	}
@@ -218,7 +220,7 @@ static void titsc_read_coordinates(struct titsc *ts_dev, 
		read = titsc_readl(ts_dev, REG_FIFO0);

		channel = read & 0xf0000;

		channel = channel >> 0x10;

		if ((channel >= 0) && (channel < ts_dev->steps_to_configure)) {

		if ((channel >= 0) && (channel < ts_dev->coordinate_readouts)) {

			read &= 0xfff;

			diff = abs(read - prev_val_x);

			if (diff < prev_diff_x) {
@@ -231,8 +233,8 @@ static void titsc_read_coordinates(struct titsc *ts_dev, 
		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))) {

		if ((channel >= ts_dev->coordinate_readouts) &&

			(channel < (2 * ts_dev->coordinate_readouts - 1))) {

			read &= 0xfff;

			diff = abs(read - prev_val_y);

			if (diff < prev_diff_y) {
@@ -310,6 +312,59 @@ static irqreturn_t titsc_irq(int irq, void *dev) 
	return IRQ_HANDLED;

}



static int titsc_parse_dt(struct platform_device *pdev,

					struct titsc *ts_dev)

{

	struct device_node *node = pdev->dev.of_node;

	int err;



	if (!node)

		return -EINVAL;



	err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);

	if (err < 0)

		return err;

	switch (ts_dev->wires) {

	case 4:

	case 5:

	case 8:

		break;

	default:

		return -EINVAL;

	}



	err = of_property_read_u32(node, "ti,x-plate-resistance",

			&ts_dev->x_plate_resistance);

	if (err < 0)

		return err;



	err = of_property_read_u32(node, "ti,coordiante-readouts",

			&ts_dev->coordinate_readouts);

	if (err < 0)

		return err;



	return of_property_read_u32_array(node, "ti,wire-config",

			ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));

}



static int titsc_parse_pdata(struct ti_tscadc_dev *tscadc_dev,

					struct titsc *ts_dev)

{

	struct mfd_tscadc_board	*pdata = tscadc_dev->dev->platform_data;



	if (!pdata)

		return -EINVAL;



	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));

	return 0;

}



/*

 * The functions for inserting/removing driver as a module.

 */
@@ -319,16 +374,8 @@ static int titsc_probe(struct platform_device *pdev) 
	struct titsc *ts_dev;

	struct input_dev *input_dev;

	struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);

	struct mfd_tscadc_board	*pdata;

	int err;



	pdata = tscadc_dev->dev->platform_data;



	if (!pdata) {

		dev_err(&pdev->dev, "Could not find platform data\n");

		return -EINVAL;

	}



	/* Allocate memory for device */

	ts_dev = kzalloc(sizeof(struct titsc), GFP_KERNEL);

	input_dev = input_allocate_device();
@@ -342,11 +389,16 @@ static int titsc_probe(struct platform_device *pdev) 
	ts_dev->mfd_tscadc = tscadc_dev;

	ts_dev->input = input_dev;

	ts_dev->irq = tscadc_dev->irq;

	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));



	if (tscadc_dev->dev->platform_data)

		err = titsc_parse_pdata(tscadc_dev, ts_dev);

	else

		err = titsc_parse_dt(pdev, ts_dev);



	if (err) {

		dev_err(&pdev->dev, "Could not find valid DT data.\n");

		goto err_free_mem;

	}



	err = request_irq(ts_dev->irq, titsc_irq,

			  0, pdev->dev.driver->name, ts_dev);
@@ -362,7 +414,7 @@ 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->steps_to_configure);

	titsc_writel(ts_dev, REG_FIFO0THR, ts_dev->coordinate_readouts);



	input_dev->name = "ti-tsc";

	input_dev->dev.parent = &pdev->dev;
@@ -398,7 +450,7 @@ static int titsc_remove(struct platform_device *pdev) 
	free_irq(ts_dev->irq, ts_dev);



	/* total steps followed by the enable mask */

	steps = 2 * ts_dev->steps_to_configure + 2;

	steps = 2 * ts_dev->coordinate_readouts + 2;

	steps = (1 << steps) - 1;

	am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
@@ -439,7 +491,7 @@ static int titsc_resume(struct device *dev) 
	}

	titsc_step_config(ts_dev);

	titsc_writel(ts_dev, REG_FIFO0THR,

			ts_dev->steps_to_configure);

			ts_dev->coordinate_readouts);

	return 0;

}
@@ -452,6 +504,12 @@ static const struct dev_pm_ops titsc_pm_ops = { 
#define TITSC_PM_OPS NULL

#endif



static const struct of_device_id ti_tsc_dt_ids[] = {

	{ .compatible = "ti,am3359-tsc", },

	{ }

};

MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);



static struct platform_driver ti_tsc_driver = {

	.probe	= titsc_probe,

	.remove	= titsc_remove,
@@ -459,6 +517,7 @@ static struct platform_driver ti_tsc_driver = { 
		.name   = "tsc",

		.owner	= THIS_MODULE,

		.pm	= TITSC_PM_OPS,

		.of_match_table = of_match_ptr(ti_tsc_dt_ids),

	},

};

module_platform_driver(ti_tsc_driver);

drivers/mfd/ti_am335x_tscadc.c

+1 −0
Original line number Diff line number Diff line
@@ -203,6 +203,7 @@ static int ti_tscadc_probe(struct platform_device *pdev) 
	/* TSC Cell */

	cell = &tscadc->cells[TSC_CELL];

	cell->name = "tsc";

	cell->of_compatible = "ti,am3359-tsc";

	cell->platform_data = &tscadc;

	cell->pdata_size = sizeof(tscadc);