Input: add ST1232 touchscreen controller driver

This patch introduces support for Sitronix ST1232 integrated capacitive
touchscreen with LCD module. The touchscreen is multitouch capable and
can report coordinates of up to two contact points.

Signed-off-by: Tony SIM <chinyeow.sim.xt@renesas.com>
Reviewed-by: Trilok Soni <tsoni@codeaurora.org>
Acked-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/Kconfig

@@ -659,17 +659,17 @@ config TOUCHSCREEN_PCAP
 	  To compile this driver as a module, choose M here: the
 	  module will be called pcap_ts.
 
-config TOUCHSCREEN_TPS6507X
-	tristate "TPS6507x based touchscreens"
+config TOUCHSCREEN_ST1232
+	tristate "Sitronix ST1232 touchscreen controllers"
 	depends on I2C
 	help
-	  Say Y here if you have a TPS6507x based touchscreen
-	  controller.
+	  Say Y here if you want to support Sitronix ST1232
+	  touchscreen controller.
 
 	  If unsure, say N.
 
 	  To compile this driver as a module, choose M here: the
-	  module will be called tps6507x_ts.
+	  module will be called st1232_ts.
 
 config TOUCHSCREEN_STMPE
 	tristate "STMicroelectronics STMPE touchscreens"
@@ -681,4 +681,16 @@ config TOUCHSCREEN_STMPE
 	  To compile this driver as a module, choose M here: the
 	  module will be called stmpe-ts.
 
+config TOUCHSCREEN_TPS6507X
+	tristate "TPS6507x based touchscreens"
+	depends on I2C
+	help
+	  Say Y here if you have a TPS6507x based touchscreen
+	  controller.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called tps6507x_ts.
+
 endif

drivers/input/touchscreen/Makefile

@@ -39,6 +39,7 @@ obj-$(CONFIG_TOUCHSCREEN_PCAP)		+= pcap_ts.o
 obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)	+= penmount.o
 obj-$(CONFIG_TOUCHSCREEN_QT602240)	+= qt602240_ts.o
 obj-$(CONFIG_TOUCHSCREEN_S3C2410)	+= s3c2410_ts.o
+obj-$(CONFIG_TOUCHSCREEN_ST1232)	+= st1232.o
 obj-$(CONFIG_TOUCHSCREEN_STMPE)		+= stmpe-ts.o
 obj-$(CONFIG_TOUCHSCREEN_TNETV107X)	+= tnetv107x-ts.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)	+= touchit213.o

drivers/input/touchscreen/st1232.c

@@ -0,0 +1,274 @@
+/*
+ * ST1232 Touchscreen Controller Driver
+ *
+ * Copyright (C) 2010 Renesas Solutions Corp.
+ *	Tony SIM <chinyeow.sim.xt@renesas.com>
+ *
+ * Using code from:
+ *  - android.git.kernel.org: projects/kernel/common.git: synaptics_i2c_rmi.c
+ *	Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define ST1232_TS_NAME	"st1232-ts"
+
+#define MIN_X		0x00
+#define MIN_Y		0x00
+#define MAX_X		0x31f	/* (800 - 1) */
+#define MAX_Y		0x1df	/* (480 - 1) */
+#define MAX_AREA	0xff
+#define MAX_FINGERS	2
+
+struct st1232_ts_finger {
+	u16 x;
+	u16 y;
+	u8 t;
+	bool is_valid;
+};
+
+struct st1232_ts_data {
+	struct i2c_client *client;
+	struct input_dev *input_dev;
+	struct st1232_ts_finger finger[MAX_FINGERS];
+};
+
+static int st1232_ts_read_data(struct st1232_ts_data *ts)
+{
+	struct st1232_ts_finger *finger = ts->finger;
+	struct i2c_client *client = ts->client;
+	struct i2c_msg msg[2];
+	int error;
+	u8 start_reg;
+	u8 buf[10];
+
+	/* read touchscreen data from ST1232 */
+	msg[0].addr = client->addr;
+	msg[0].flags = 0;
+	msg[0].len = 1;
+	msg[0].buf = &start_reg;
+	start_reg = 0x10;
+
+	msg[1].addr = ts->client->addr;
+	msg[1].flags = I2C_M_RD;
+	msg[1].len = sizeof(buf);
+	msg[1].buf = buf;
+
+	error = i2c_transfer(client->adapter, msg, 2);
+	if (error < 0)
+		return error;
+
+	/* get "valid" bits */
+	finger[0].is_valid = buf[2] >> 7;
+	finger[1].is_valid = buf[5] >> 7;
+
+	/* get xy coordinate */
+	if (finger[0].is_valid) {
+		finger[0].x = ((buf[2] & 0x0070) << 4) | buf[3];
+		finger[0].y = ((buf[2] & 0x0007) << 8) | buf[4];
+		finger[0].t = buf[8];
+	}
+
+	if (finger[1].is_valid) {
+		finger[1].x = ((buf[5] & 0x0070) << 4) | buf[6];
+		finger[1].y = ((buf[5] & 0x0007) << 8) | buf[7];
+		finger[1].t = buf[9];
+	}
+
+	return 0;
+}
+
+static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
+{
+	struct st1232_ts_data *ts = dev_id;
+	struct st1232_ts_finger *finger = ts->finger;
+	struct input_dev *input_dev = ts->input_dev;
+	int count = 0;
+	int i, ret;
+
+	ret = st1232_ts_read_data(ts);
+	if (ret < 0)
+		goto end;
+
+	/* multi touch protocol */
+	for (i = 0; i < MAX_FINGERS; i++) {
+		if (!finger[i].is_valid)
+			continue;
+
+		input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, finger[i].t);
+		input_report_abs(input_dev, ABS_MT_POSITION_X, finger[i].x);
+		input_report_abs(input_dev, ABS_MT_POSITION_Y, finger[i].y);
+		input_mt_sync(input_dev);
+		count++;
+	}
+
+	/* SYN_MT_REPORT only if no contact */
+	if (!count)
+		input_mt_sync(input_dev);
+
+	/* SYN_REPORT */
+	input_sync(input_dev);
+
+end:
+	return IRQ_HANDLED;
+}
+
+static int __devinit st1232_ts_probe(struct i2c_client *client,
+					const struct i2c_device_id *id)
+{
+	struct st1232_ts_data *ts;
+	struct input_dev *input_dev;
+	int error;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev, "need I2C_FUNC_I2C\n");
+		return -EIO;
+	}
+
+	if (!client->irq) {
+		dev_err(&client->dev, "no IRQ?\n");
+		return -EINVAL;
+	}
+
+
+	ts = kzalloc(sizeof(struct st1232_ts_data), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!ts || !input_dev) {
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	ts->client = client;
+	ts->input_dev = input_dev;
+
+	input_dev->name = "st1232-touchscreen";
+	input_dev->id.bustype = BUS_I2C;
+	input_dev->dev.parent = &client->dev;
+
+	__set_bit(EV_SYN, input_dev->evbit);
+	__set_bit(EV_KEY, input_dev->evbit);
+	__set_bit(EV_ABS, input_dev->evbit);
+
+	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_POSITION_X, MIN_X, MAX_X, 0, 0);
+	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, MIN_Y, MAX_Y, 0, 0);
+
+	error = request_threaded_irq(client->irq, NULL, st1232_ts_irq_handler,
+				     IRQF_ONESHOT, client->name, ts);
+	if (error) {
+		dev_err(&client->dev, "Failed to register interrupt\n");
+		goto err_free_mem;
+	}
+
+	error = input_register_device(ts->input_dev);
+	if (error) {
+		dev_err(&client->dev, "Unable to register %s input device\n",
+			input_dev->name);
+		goto err_free_irq;
+	}
+
+	i2c_set_clientdata(client, ts);
+	device_init_wakeup(&client->dev, 1);
+
+	return 0;
+
+err_free_irq:
+	free_irq(client->irq, ts);
+err_free_mem:
+	input_free_device(input_dev);
+	kfree(ts);
+	return error;
+}
+
+static int __devexit st1232_ts_remove(struct i2c_client *client)
+{
+	struct st1232_ts_data *ts = i2c_get_clientdata(client);
+
+	device_init_wakeup(&client->dev, 0);
+	free_irq(client->irq, ts);
+	input_unregister_device(ts->input_dev);
+	kfree(ts);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int st1232_ts_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	if (device_may_wakeup(&client->dev))
+		enable_irq_wake(client->irq);
+	else
+		disable_irq(client->irq);
+
+	return 0;
+}
+
+static int st1232_ts_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	if (device_may_wakeup(&client->dev))
+		disable_irq_wake(client->irq);
+	else
+		enable_irq(client->irq);
+
+	return 0;
+}
+
+static const struct dev_pm_ops st1232_ts_pm_ops = {
+	.suspend	= st1232_ts_suspend,
+	.resume		= st1232_ts_resume,
+};
+#endif
+
+static const struct i2c_device_id st1232_ts_id[] = {
+	{ ST1232_TS_NAME, 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, st1232_ts_id);
+
+static struct i2c_driver st1232_ts_driver = {
+	.probe		= st1232_ts_probe,
+	.remove		= __devexit_p(st1232_ts_remove),
+	.id_table	= st1232_ts_id,
+	.driver = {
+		.name	= ST1232_TS_NAME,
+		.owner	= THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm	= &st1232_ts_pm_ops,
+#endif
+	},
+};
+
+static int __init st1232_ts_init(void)
+{
+	return i2c_add_driver(&st1232_ts_driver);
+}
+module_init(st1232_ts_init);
+
+static void __exit st1232_ts_exit(void)
+{
+	i2c_del_driver(&st1232_ts_driver);
+}
+module_exit(st1232_ts_exit);
+
+MODULE_AUTHOR("Tony SIM <chinyeow.sim.xt@renesas.com>");
+MODULE_DESCRIPTION("SITRONIX ST1232 Touchscreen Controller Driver");
+MODULE_LICENSE("GPL");