ENGR00069342 Add Touchscreen Support for MX37 3Stack Board

Add Support for Touchscreen on the 3-Stack board

Signed-off-by: Mahesh Mahadevan <r9aadq@freescale.com>

3 files changed, 350 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 9b0692a19618..9e49ffc55d6f 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -275,4 +275,12 @@ config TOUCHSCREEN_USB_GOTOP
 	bool "GoTop Super_Q2/GogoPen/PenPower tablet device support" if EMBEDDED
 	depends on TOUCHSCREEN_USB_COMPOSITE
 
+config TOUCHSCREEN_TSC2007
+	tristate "TI Touch Screen Controller Chip TSC2007"
+	depends on ARCH_MX37
+	help
+	  If you say yes here you get support for TSC2007 touch screen controller chip.
+	 
+	  This driver can also be built as a module.  If so, the module
+	  will be called tsc2007.
 endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 364ae57f3e58..cf53b2affc31 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -20,3 +20,4 @@ obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)	+= penmount.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)	+= touchright.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)	+= touchwin.o
 obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o
+obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o
diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
new file mode 100644
index 000000000000..f59fcff2b6f4
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -0,0 +1,341 @@
+/*
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/*!
+ * @file tsc2007.c
+ *
+ * @brief Driver for TI's tsc2007 I2C Touch Screen Controller.
+ *
+ * This driver is based on the driver written by Bill Gatliff
+ *  Copyright (C) 2005 Bill Gatliff <bgat at billgatliff.com>
+ *  Changes for 2.6.20 kernel by Nicholas Chen <nchen at cs.umd.edu>
+ *
+ * @ingroup touchscreen
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/string.h>
+#include <linux/bcd.h>
+#include <linux/list.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/kthread.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+#include <asm/mach/irq.h>
+
+#define DRIVER_NAME "TSC2007"
+
+enum tsc2007_pd {
+	PD_POWERDOWN = 0,	/* penirq */
+	PD_IREFOFF_ADCON = 1,	/* no penirq */
+	PD_IREFON_ADCOFF = 2,	/* penirq */
+	PD_IREFON_ADCON = 3,	/* no penirq */
+	PD_PENIRQ_ARM = PD_IREFON_ADCOFF,
+	PD_PENIRQ_DISARM = PD_IREFON_ADCON,
+};
+
+enum tsc2007_m {
+	M_12BIT = 0,
+	M_8BIT = 1
+};
+
+enum tsc2007_cmd {
+	MEAS_TEMP0 = 0,
+	MEAS_IN1 = 2,
+	MEAS_XPOS = 12,
+	MEAS_YPOS = 13,
+	MEAS_Z1POS = 14,
+	MEAS_Z2POS = 15
+};
+
+#define tsc2007_CMD(cn, pdn, m) (((cn) << 4) | ((pdn) << 2) | ((m) << 1))
+
+#define ADC_MAX ((1 << 12) - 1)
+
+struct tsc2007_data {
+	struct i2c_client *client;
+	struct input_dev *idev;
+	struct timer_list penirq_timer;
+	struct task_struct *tstask;
+	u32 ts_thread_cnt;
+	struct completion penirq_completion;
+	struct completion penup_completion;
+	enum tsc2007_m m;
+	int penirq;
+};
+
+static int tsc2007_read(struct tsc2007_data *data,
+			enum tsc2007_cmd cmd, enum tsc2007_pd pd, int *val)
+{
+	unsigned char c;
+	unsigned char d[2];
+	int ret;
+
+	c = tsc2007_CMD(cmd, pd, data->m);
+
+	ret = i2c_master_send(data->client, &c, 1);
+
+	if (ret < 0)
+		goto err;
+
+	udelay(20);
+	ret = i2c_master_recv(data->client, d, data->m == M_12BIT ? 2 : 1);
+	if (ret < 0)
+		goto err;
+
+	if (val) {
+		*val = d[0];
+		*val <<= 4;
+		if (data->m == M_12BIT)
+			*val += (d[1] >> 4);
+	}
+
+	return 0;
+err:
+	return -ENODEV;
+}
+
+static inline int tsc2007_read_xpos(struct tsc2007_data *d, enum
+				    tsc2007_pd pd, int *x)
+{
+	return tsc2007_read(d, MEAS_XPOS, pd, x);
+}
+
+static inline int tsc2007_read_ypos(struct tsc2007_data *d, enum
+				    tsc2007_pd pd, int *y)
+{
+	return tsc2007_read(d, MEAS_YPOS, pd, y);
+}
+
+static inline int tsc2007_read_pressure(struct tsc2007_data *d, enum
+					tsc2007_pd pd, int *p)
+{
+	return tsc2007_read(d, MEAS_Z1POS, pd, p);
+}
+
+static inline int tsc2007_powerdown(struct tsc2007_data *d)
+{
+	/* we don't have a distinct powerdown command,
+	   so do a benign read with the PD bits cleared */
+	return tsc2007_read(d, MEAS_IN1, PD_POWERDOWN, 0);
+}
+
+#define PENUP_TIMEOUT		10
+
+static irqreturn_t tsc2007_penirq(int irq, void *v)
+{
+	struct tsc2007_data *d = v;
+
+	disable_irq(d->penirq);
+	complete(&d->penirq_completion);
+	return IRQ_HANDLED;
+}
+
+static void tsc2007_pen_up(unsigned long v)
+{
+	struct tsc2007_data *d = (struct tsc2007_data *)v;
+
+	complete(&d->penup_completion);
+	return;
+}
+
+static inline void tsc2007_restart_pen_up_timer(struct tsc2007_data *d)
+{
+	mod_timer(&d->penirq_timer, jiffies + (PENUP_TIMEOUT * HZ) / 1000);
+}
+
+static int tsc2007ts_thread(void *v)
+{
+	struct tsc2007_data *d = v;
+
+	if (d->ts_thread_cnt)
+		return -EINVAL;
+	d->ts_thread_cnt = 1;
+
+	while (1) {
+		unsigned int x = 0, y = 0, p = 0;
+
+		/* Wait for an Pen down interrupt */
+		wait_for_completion(&d->penirq_completion);
+		tsc2007_read_xpos(d, PD_PENIRQ_DISARM, &x);
+		tsc2007_read_ypos(d, PD_PENIRQ_DISARM, &y);
+		tsc2007_read_pressure(d, PD_PENIRQ_DISARM, &p);
+		input_report_abs(d->idev, ABS_X, 4096 - x);
+		input_report_abs(d->idev, ABS_Y, 4096 - y);
+		input_report_abs(d->idev, ABS_PRESSURE, p);
+		input_sync(d->idev);
+
+		while (p > 10) {
+			tsc2007_restart_pen_up_timer(d);
+			wait_for_completion_interruptible(&d->penup_completion);
+			/* Pen Down */
+			tsc2007_read_xpos(d, PD_PENIRQ_DISARM, &x);
+			tsc2007_read_ypos(d, PD_PENIRQ_DISARM, &y);
+			tsc2007_read_pressure(d, PD_PENIRQ_DISARM, &p);
+			if (p <= 10)
+				break;
+
+			input_report_abs(d->idev, ABS_X, 4096 - x);
+			input_report_abs(d->idev, ABS_Y, 4096 - y);
+			input_report_abs(d->idev, ABS_PRESSURE, p);
+			input_sync(d->idev);
+		};
+
+		/* Pen Up */
+		input_report_abs(d->idev, ABS_X, 4096 - x);
+		input_report_abs(d->idev, ABS_Y, 4096 - y);
+		input_report_abs(d->idev, ABS_PRESSURE, 0);
+		input_sync(d->idev);
+
+		tsc2007_read(d, MEAS_TEMP0, PD_PENIRQ_ARM, 0);
+		enable_irq(d->penirq);
+
+		if (kthread_should_stop())
+			break;
+	}
+
+	d->ts_thread_cnt = 0;
+	return 0;
+}
+
+static int tsc2007_idev_open(struct input_dev *idev)
+{
+	struct tsc2007_data *d = idev->private;
+	int ret = 0;
+
+	d->penirq_timer.data = (unsigned long)d;
+	d->penirq_timer.function = tsc2007_pen_up;
+
+	d->tstask = kthread_run(tsc2007ts_thread, d, DRIVER_NAME "tsd");
+	if (IS_ERR(d->tstask))
+		ret = PTR_ERR(d->tstask);
+
+	return ret;
+}
+
+static int tsc2007_driver_register(struct tsc2007_data *data)
+{
+	struct input_dev *idev;
+	int ret = 0;
+
+	init_timer(&data->penirq_timer);
+	data->penirq_timer.data = (unsigned long)data;
+	data->penirq_timer.function = tsc2007_pen_up;
+
+	if (data->penirq) {
+		ret =
+		    request_irq(data->penirq, tsc2007_penirq, IRQT_LOW,
+				DRIVER_NAME, data);
+		if (!ret) {
+			printk(KERN_INFO "%s: Registering Touchscreen device\n",
+			       __func__);
+			init_completion(&data->penirq_completion);
+			init_completion(&data->penup_completion);
+		} else {
+			printk(KERN_ERR "%s: Cannot grab irq %d\n",
+			       __func__, data->penirq);
+		}
+	}
+	idev = input_allocate_device();
+	data->idev = idev;
+	idev->private = data;
+	idev->name = DRIVER_NAME;
+	idev->evbit[0] = BIT(EV_ABS);
+	idev->open = tsc2007_idev_open;
+	idev->absbit[0] = BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE);
+	input_set_abs_params(idev, ABS_X, 0, ADC_MAX, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, ADC_MAX, 0, 0);
+	input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
+
+	if (!ret)
+		ret = input_register_device(idev);
+
+	return ret;
+}
+
+static int tsc2007_i2c_remove(struct i2c_client *client)
+{
+	int err;
+	struct tsc2007_data *d = i2c_get_clientdata(client);
+
+	kthread_stop(d->tstask);
+	free_irq(d->penirq, d);
+	input_unregister_device(d->idev);
+
+	err = i2c_detach_client(client);
+	if (err) {
+		dev_err(&client->dev, "Client deregistration failed, "
+			"client not detached.\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static int tsc2007_i2c_probe(struct i2c_client *client)
+{
+	struct tsc2007_data *data;
+	int err = 0;
+
+	data = kzalloc(sizeof(struct tsc2007_data), GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, data);
+	data->client = client;
+	data->penirq = client->irq;
+
+	err = tsc2007_powerdown(data);
+	if (err >= 0) {
+		data->m = M_12BIT;
+
+		err = tsc2007_driver_register(data);
+		if (err < 0)
+			goto exit;
+
+		return 0;
+	}
+
+exit:
+	return err;
+}
+
+static struct i2c_driver tsc2007_driver = {
+	.driver = {
+		   .name = DRIVER_NAME,
+		   },
+	.probe = tsc2007_i2c_probe,
+	.remove = tsc2007_i2c_remove,
+	.command = NULL,
+};
+
+static int __init tsc2007_init(void)
+{
+	return i2c_add_driver(&tsc2007_driver);
+}
+
+static void __exit tsc2007_exit(void)
+{
+	i2c_del_driver(&tsc2007_driver);
+}
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("tsc2007 Touch Screen Controller driver");
+MODULE_LICENSE("GPL");
+
+module_init(tsc2007_init);
+module_exit(tsc2007_exit);