Input: tsc2005 - add DT support

This adds DT support to the tsc2005 touchscreen driver. It also adds
regulator support to the driver if booted via DT.

Reviewed-by: Pavel Machek <[e-mail]>
Acked-by: Aaro Koskinen <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

Documentation/devicetree/bindings/input/touchscreen/tsc2005.txt

···
+* Texas Instruments tsc2005 touchscreen controller
+
+Required properties:
+ - compatible		      : "ti,tsc2005"
+ - reg			      : SPI device address
+ - spi-max-frequency	      : Maximal SPI speed
+ - interrupts		      : IRQ specifier
+ - reset-gpios		      : GPIO specifier
+ - vio-supply                 : Regulator specifier
+
+Optional properties:
+ - ti,x-plate-ohms	      : integer, resistance of the touchscreen's X plates
+				in ohm (defaults to 280)
+ - ti,esd-recovery-timeout-ms : integer, if the touchscreen does not respond after
+				the configured time (in milli seconds), the driver
+				will reset it. This is disabled by default.
+ - properties defined in touchscreen.txt
+
+Example:
+
+&mcspi1 {
+	tsc2005@0 {
+		compatible = "ti,tsc2005";
+		spi-max-frequency = <6000000>;
+		reg = <0>;
+
+		vio-supply = <&vio>;
+
+		reset-gpios = <&gpio4 8 GPIO_ACTIVE_HIGH>; /* 104 */
+		interrupts-extended = <&gpio4 4 IRQ_TYPE_EDGE_RISING>; /* 100 */
+
+		touchscreen-fuzz-x = <4>;
+		touchscreen-fuzz-y = <7>;
+		touchscreen-fuzz-pressure = <2>;
+		touchscreen-max-x = <4096>;
+		touchscreen-max-y = <4096>;
+		touchscreen-max-pressure = <2048>;
+
+		ti,x-plate-ohms = <280>;
+		ti,esd-recovery-timeout-ms = <8000>;
+	};
+}

drivers/input/touchscreen/tsc2005.c

···
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/input.h>
+#include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/pm.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/tsc2005.h>
+#include <linux/regulator/consumer.h>
 
 /*
  * The touchscreen interface operates as follows:
···
 					 TSC2005_CFR2_AVG_7)
 
 #define MAX_12BIT			0xfff
+#define TSC2005_DEF_X_FUZZ		4
+#define TSC2005_DEF_Y_FUZZ		8
+#define TSC2005_DEF_P_FUZZ		2
+#define TSC2005_DEF_RESISTOR		280
+
 #define TSC2005_SPI_MAX_SPEED_HZ	10000000
 #define TSC2005_PENUP_TIME_MS		40
 
···
 
 	bool			pen_down;
 
+	struct regulator	*vio;
+
+	int			reset_gpio;
 	void			(*set_reset)(bool enable);
 };
 
···
 	tsc2005_cmd(ts, TSC2005_CMD_STOP);
 }
 
+static void tsc2005_set_reset(struct tsc2005 *ts, bool enable)
+{
+	if (ts->reset_gpio >= 0)
+		gpio_set_value(ts->reset_gpio, enable);
+	else if (ts->set_reset)
+		ts->set_reset(enable);
+}
+
 /* must be called with ts->mutex held */
 static void __tsc2005_disable(struct tsc2005 *ts)
 {
···
 {
 	tsc2005_start_scan(ts);
 
-	if (ts->esd_timeout && ts->set_reset) {
+	if (ts->esd_timeout && (ts->set_reset || ts->reset_gpio)) {
 		ts->last_valid_interrupt = jiffies;
 		schedule_delayed_work(&ts->esd_work,
 				round_jiffies_relative(
···
 	}
 
 	/* hardware reset */
-	ts->set_reset(false);
+	tsc2005_set_reset(ts, false);
 	usleep_range(100, 500); /* only 10us required */
-	ts->set_reset(true);
+	tsc2005_set_reset(ts, true);
 
 	if (!success)
 		goto out;
···
 	umode_t mode = attr->mode;
 
 	if (attr == &dev_attr_selftest.attr) {
-		if (!ts->set_reset)
+		if (!ts->set_reset && !ts->reset_gpio)
 			mode = 0;
 	}
 
···
 
 	tsc2005_update_pen_state(ts, 0, 0, 0);
 
-	ts->set_reset(false);
+	tsc2005_set_reset(ts, false);
 	usleep_range(100, 500); /* only 10us required */
-	ts->set_reset(true);
+	tsc2005_set_reset(ts, true);
 
 	enable_irq(ts->spi->irq);
 	tsc2005_start_scan(ts);
···
 static int tsc2005_probe(struct spi_device *spi)
 {
 	const struct tsc2005_platform_data *pdata = dev_get_platdata(&spi->dev);
+	struct device_node *np = spi->dev.of_node;
+
 	struct tsc2005 *ts;
 	struct input_dev *input_dev;
-	unsigned int max_x, max_y, max_p;
-	unsigned int fudge_x, fudge_y, fudge_p;
+	unsigned int max_x = MAX_12BIT;
+	unsigned int max_y = MAX_12BIT;
+	unsigned int max_p = MAX_12BIT;
+	unsigned int fudge_x = TSC2005_DEF_X_FUZZ;
+	unsigned int fudge_y = TSC2005_DEF_Y_FUZZ;
+	unsigned int fudge_p = TSC2005_DEF_P_FUZZ;
+	unsigned int x_plate_ohm = TSC2005_DEF_RESISTOR;
+	unsigned int esd_timeout;
 	int error;
 
-	if (!pdata) {
+	if (!np && !pdata) {
 		dev_err(&spi->dev, "no platform data\n");
 		return -ENODEV;
 	}
 
-	fudge_x	= pdata->ts_x_fudge	   ? : 4;
-	fudge_y	= pdata->ts_y_fudge	   ? : 8;
-	fudge_p	= pdata->ts_pressure_fudge ? : 2;
-	max_x	= pdata->ts_x_max	   ? : MAX_12BIT;
-	max_y	= pdata->ts_y_max	   ? : MAX_12BIT;
-	max_p	= pdata->ts_pressure_max   ? : MAX_12BIT;
-
 	if (spi->irq <= 0) {
 		dev_err(&spi->dev, "no irq\n");
 		return -ENODEV;
+	}
+
+	if (pdata) {
+		fudge_x	= pdata->ts_x_fudge;
+		fudge_y	= pdata->ts_y_fudge;
+		fudge_p	= pdata->ts_pressure_fudge;
+		max_x	= pdata->ts_x_max;
+		max_y	= pdata->ts_y_max;
+		max_p	= pdata->ts_pressure_max;
+		x_plate_ohm = pdata->ts_x_plate_ohm;
+		esd_timeout = pdata->esd_timeout_ms;
+	} else {
+		x_plate_ohm = TSC2005_DEF_RESISTOR;
+		of_property_read_u32(np, "ti,x-plate-ohms", &x_plate_ohm);
+		esd_timeout = 0;
+		of_property_read_u32(np, "ti,esd-recovery-timeout-ms",
+								&esd_timeout);
 	}
 
 	spi->mode = SPI_MODE_0;
···
 	ts->spi = spi;
 	ts->idev = input_dev;
 
-	ts->x_plate_ohm	= pdata->ts_x_plate_ohm	? : 280;
-	ts->esd_timeout	= pdata->esd_timeout_ms;
-	ts->set_reset	= pdata->set_reset;
+	ts->x_plate_ohm = x_plate_ohm;
+	ts->esd_timeout = esd_timeout;
+
+	if (np) {
+		ts->reset_gpio = of_get_named_gpio(np, "reset-gpios", 0);
+		if (ts->reset_gpio == -EPROBE_DEFER)
+			return ts->reset_gpio;
+		if (ts->reset_gpio < 0) {
+			dev_err(&spi->dev, "error acquiring reset gpio: %d\n",
+				ts->reset_gpio);
+			return ts->reset_gpio;
+		}
+
+		error = devm_gpio_request_one(&spi->dev, ts->reset_gpio, 0,
+					      "reset-gpios");
+		if (error) {
+			dev_err(&spi->dev, "error requesting reset gpio: %d\n",
+				error);
+			return error;
+		}
+
+		ts->vio = devm_regulator_get(&spi->dev, "vio");
+		if (IS_ERR(ts->vio)) {
+			error = PTR_ERR(ts->vio);
+			dev_err(&spi->dev, "vio regulator missing (%d)", error);
+			return error;
+		}
+	} else {
+		ts->reset_gpio = -1;
+		ts->set_reset = pdata->set_reset;
+	}
 
 	mutex_init(&ts->mutex);
 
···
 	input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0);
 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
 
+	if (np)
+		touchscreen_parse_of_params(input_dev);
+
 	input_dev->open = tsc2005_open;
 	input_dev->close = tsc2005_close;
 
···
 		return error;
 	}
 
+	/* enable regulator for DT */
+	if (ts->vio) {
+		error = regulator_enable(ts->vio);
+		if (error)
+			return error;
+	}
+
 	spi_set_drvdata(spi, ts);
 	error = sysfs_create_group(&spi->dev.kobj, &tsc2005_attr_group);
 	if (error) {
 		dev_err(&spi->dev,
 			"Failed to create sysfs attributes, err: %d\n", error);
-		return error;
+		goto disable_regulator;
 	}
 
 	error = input_register_device(ts->idev);
···
 
 err_remove_sysfs:
 	sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group);
+disable_regulator:
+	if (ts->vio)
+		regulator_disable(ts->vio);
 	return error;
 }
 
 static int tsc2005_remove(struct spi_device *spi)
 {
+	struct tsc2005 *ts = spi_get_drvdata(spi);
+
 	sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group);
+
+	if (ts->vio)
+		regulator_disable(ts->vio);
 
 	return 0;
 }