Input: add support for Semtech SX8654 I2C touchscreen controller

Signed-off-by: Sébastien Szymanski <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

Documentation/devicetree/bindings/input/touchscreen/sx8654.txt

···
+* Semtech SX8654 I2C Touchscreen Controller
+
+Required properties:
+- compatible: must be "semtech,sx8654"
+- reg: i2c slave address
+- interrupt-parent: the phandle for the interrupt controller
+- interrupts: touch controller interrupt
+
+Example:
+
+	sx8654@48 {
+		compatible = "semtech,sx8654";
+		reg = <0x48>;
+		interrupt-parent = <&gpio6>;
+		interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
+	};

drivers/input/touchscreen/Kconfig

···
 	  To compile this driver as a module, choose M here: the
 	  module will be called sur40.
 
+config TOUCHSCREEN_SX8654
+	tristate "Semtech SX8654 touchscreen"
+	depends on I2C
+	help
+	  Say Y here if you have a Semtech SX8654 touchscreen controller.
+
+	  If unsure, say N
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called sx8654.
+
 config TOUCHSCREEN_TPS6507X
 	tristate "TPS6507x based touchscreens"
 	depends on I2C

drivers/input/touchscreen/Makefile

···
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)	+= mainstone-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE)	+= zylonite-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_W90X900)	+= w90p910_ts.o
+obj-$(CONFIG_TOUCHSCREEN_SX8654)	+= sx8654.o
 obj-$(CONFIG_TOUCHSCREEN_TPS6507X)	+= tps6507x-ts.o
 obj-$(CONFIG_TOUCHSCREEN_ZFORCE)	+= zforce_ts.o

drivers/input/touchscreen/sx8654.c

···
+/*
+ * Driver for Semtech SX8654 I2C touchscreen controller.
+ *
+ * Copyright (c) 2015 Armadeus Systems
+ *	Sébastien Szymanski <[e-mail]>
+ *
+ * Using code from:
+ *  - sx865x.c
+ *	Copyright (c) 2013 U-MoBo Srl
+ *	Pierluigi Passaro <[e-mail]>
+ *  - sx8650.c
+ *      Copyright (c) 2009 Wayne Roberts
+ *  - tsc2007.c
+ *      Copyright (c) 2008 Kwangwoo Lee
+ *  - ads7846.c
+ *      Copyright (c) 2005 David Brownell
+ *      Copyright (c) 2006 Nokia Corporation
+ *  - corgi_ts.c
+ *      Copyright (C) 2004-2005 Richard Purdie
+ *  - omap_ts.[hc], ads7846.h, ts_osk.c
+ *      Copyright (C) 2002 MontaVista Software
+ *      Copyright (C) 2004 Texas Instruments
+ *      Copyright (C) 2005 Dirk Behme
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+/* register addresses */
+#define I2C_REG_TOUCH0			0x00
+#define I2C_REG_TOUCH1			0x01
+#define I2C_REG_CHANMASK		0x04
+#define I2C_REG_IRQMASK			0x22
+#define I2C_REG_IRQSRC			0x23
+#define I2C_REG_SOFTRESET		0x3f
+
+/* commands */
+#define CMD_READ_REGISTER		0x40
+#define CMD_MANUAL			0xc0
+#define CMD_PENTRG			0xe0
+
+/* value for I2C_REG_SOFTRESET */
+#define SOFTRESET_VALUE			0xde
+
+/* bits for I2C_REG_IRQSRC */
+#define IRQ_PENTOUCH_TOUCHCONVDONE	0x08
+#define IRQ_PENRELEASE			0x04
+
+/* bits for RegTouch1 */
+#define CONDIRQ				0x20
+#define FILT_7SA			0x03
+
+/* bits for I2C_REG_CHANMASK */
+#define CONV_X				0x80
+#define CONV_Y				0x40
+
+/* coordinates rate: higher nibble of CTRL0 register */
+#define RATE_MANUAL			0x00
+#define RATE_5000CPS			0xf0
+
+/* power delay: lower nibble of CTRL0 register */
+#define POWDLY_1_1MS			0x0b
+
+#define MAX_12BIT			((1 << 12) - 1)
+
+struct sx8654 {
+	struct input_dev *input;
+	struct i2c_client *client;
+};
+
+static irqreturn_t sx8654_irq(int irq, void *handle)
+{
+	struct sx8654 *sx8654 = handle;
+	u8 irqsrc;
+	u8 data[4];
+	unsigned int x, y;
+	int retval;
+
+	irqsrc = i2c_smbus_read_byte_data(sx8654->client,
+					  CMD_READ_REGISTER | I2C_REG_IRQSRC);
+	dev_dbg(&sx8654->client->dev, "irqsrc = 0x%x", irqsrc);
+
+	if (irqsrc < 0)
+		goto out;
+
+	if (irqsrc & IRQ_PENRELEASE) {
+		dev_dbg(&sx8654->client->dev, "pen release interrupt");
+
+		input_report_key(sx8654->input, BTN_TOUCH, 0);
+		input_sync(sx8654->input);
+	}
+
+	if (irqsrc & IRQ_PENTOUCH_TOUCHCONVDONE) {
+		dev_dbg(&sx8654->client->dev, "pen touch interrupt");
+
+		retval = i2c_master_recv(sx8654->client, data, sizeof(data));
+		if (retval != sizeof(data))
+			goto out;
+
+		/* invalid data */
+		if (unlikely(data[0] & 0x80 || data[2] & 0x80))
+			goto out;
+
+		x = ((data[0] & 0xf) << 8) | (data[1]);
+		y = ((data[2] & 0xf) << 8) | (data[3]);
+
+		input_report_abs(sx8654->input, ABS_X, x);
+		input_report_abs(sx8654->input, ABS_Y, y);
+		input_report_key(sx8654->input, BTN_TOUCH, 1);
+		input_sync(sx8654->input);
+
+		dev_dbg(&sx8654->client->dev, "point(%4d,%4d)\n", x, y);
+	}
+
+out:
+	return IRQ_HANDLED;
+}
+
+static int sx8654_open(struct input_dev *dev)
+{
+	struct sx8654 *sx8654 = input_get_drvdata(dev);
+	struct i2c_client *client = sx8654->client;
+	int error;
+
+	/* enable pen trigger mode */
+	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0,
+					  RATE_5000CPS | POWDLY_1_1MS);
+	if (error) {
+		dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
+		return error;
+	}
+
+	error = i2c_smbus_write_byte(client, CMD_PENTRG);
+	if (error) {
+		dev_err(&client->dev, "writing command CMD_PENTRG failed");
+		return error;
+	}
+
+	enable_irq(client->irq);
+
+	return 0;
+}
+
+static void sx8654_close(struct input_dev *dev)
+{
+	struct sx8654 *sx8654 = input_get_drvdata(dev);
+	struct i2c_client *client = sx8654->client;
+	int error;
+
+	disable_irq(client->irq);
+
+	/* enable manual mode mode */
+	error = i2c_smbus_write_byte(client, CMD_MANUAL);
+	if (error) {
+		dev_err(&client->dev, "writing command CMD_MANUAL failed");
+		return;
+	}
+
+	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0, 0);
+	if (error) {
+		dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
+		return;
+	}
+}
+
+static int sx8654_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct sx8654 *sx8654;
+	struct input_dev *input;
+	int error;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -ENXIO;
+
+	sx8654 = devm_kzalloc(&client->dev, sizeof(*sx8654), GFP_KERNEL);
+	if (!sx8654)
+		return -ENOMEM;
+
+	input = devm_input_allocate_device(&client->dev);
+	if (!sx8654)
+		return -ENOMEM;
+
+	input->name = "SX8654 I2C Touchscreen";
+	input->id.bustype = BUS_I2C;
+	input->dev.parent = &client->dev;
+	input->open = sx8654_open;
+	input->close = sx8654_close;
+
+	__set_bit(INPUT_PROP_DIRECT, input->propbit);
+	input_set_capability(input, EV_KEY, BTN_TOUCH);
+	input_set_abs_params(input, ABS_X, 0, MAX_12BIT, 0, 0);
+	input_set_abs_params(input, ABS_Y, 0, MAX_12BIT, 0, 0);
+
+	sx8654->client = client;
+	sx8654->input = input;
+
+	input_set_drvdata(sx8654->input, sx8654);
+
+	error = i2c_smbus_write_byte_data(client, I2C_REG_SOFTRESET,
+					  SOFTRESET_VALUE);
+	if (error) {
+		dev_err(&client->dev, "writing softreset value failed");
+		return error;
+	}
+
+	error = i2c_smbus_write_byte_data(client, I2C_REG_CHANMASK,
+					  CONV_X | CONV_Y);
+	if (error) {
+		dev_err(&client->dev, "writing to I2C_REG_CHANMASK failed");
+		return error;
+	}
+
+	error = i2c_smbus_write_byte_data(client, I2C_REG_IRQMASK,
+					  IRQ_PENTOUCH_TOUCHCONVDONE |
+						IRQ_PENRELEASE);
+	if (error) {
+		dev_err(&client->dev, "writing to I2C_REG_IRQMASK failed");
+		return error;
+	}
+
+	error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH1,
+					  CONDIRQ | FILT_7SA);
+	if (error) {
+		dev_err(&client->dev, "writing to I2C_REG_TOUCH1 failed");
+		return error;
+	}
+
+	error = devm_request_threaded_irq(&client->dev, client->irq,
+					  NULL, sx8654_irq,
+					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					  client->name, sx8654);
+	if (error) {
+		dev_err(&client->dev,
+			"Failed to enable IRQ %d, error: %d\n",
+			client->irq, error);
+		return error;
+	}
+
+	/* Disable the IRQ, we'll enable it in sx8654_open() */
+	disable_irq(client->irq);
+
+	error = input_register_device(sx8654->input);
+	if (error)
+		return error;
+
+	i2c_set_clientdata(client, sx8654);
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sx8654_of_match[] = {
+	{ .compatible = "semtech,sx8654", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, sx8654_of_match);
+#endif
+
+static const struct i2c_device_id sx8654_id_table[] = {
+	{ "semtech_sx8654", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, sx8654_id_table);
+
+static struct i2c_driver sx8654_driver = {
+	.driver = {
+		.name = "sx8654",
+		.of_match_table = of_match_ptr(sx8654_of_match),
+	},
+	.id_table = sx8654_id_table,
+	.probe = sx8654_probe,
+};
+module_i2c_driver(sx8654_driver);
+
+MODULE_AUTHOR("Sébastien Szymanski <[e-mail]>");
+MODULE_DESCRIPTION("Semtech SX8654 I2C Touchscreen Driver");
+MODULE_LICENSE("GPL");