Re: + input-add-tsc2007-based-touchscreen-driver.patch added to -mm tree

Re: + input-add-tsc2007-based-touchscreen-driver.patch added to -mm tree

[Kwangwoo Lee]

>From d5258e21e38e38e4128112844f24621ffb1c1e86 Mon Sep 17 00:00:00 2001
From: Kwangwoo Lee <kwangwoo.lee@gmail.com>
Date: Mon, 8 Dec 2008 13:42:14 +0900
Subject: [PATCH] Add tsc2007 based touchscreen driver.

corrected some parts following in helpful comments:
Remove unnecessary headers and variables.
Use i2c_smbus_read_word_data() to prevent race condition.
Fix i2c_check_functionality() argument correctly.

Signed-off-by: Kwangwoo Lee <kwangwoo.lee@gmail.com>
---
 drivers/input/touchscreen/Kconfig   |    9 +
 drivers/input/touchscreen/Makefile  |    1 +
 drivers/input/touchscreen/tsc2007.c |  378 +++++++++++++++++++++++++++++++++++
 include/linux/i2c/tsc2007.h         |   17 ++
 4 files changed, 405 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/touchscreen/tsc2007.c
 create mode 100644 include/linux/i2c/tsc2007.h

diff --git a/drivers/input/touchscreen/Kconfig
b/drivers/input/touchscreen/Kconfig
index 3d1ab8f..78abdfb 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -376,4 +376,13 @@ config TOUCHSCREEN_TOUCHIT213
 	  To compile this driver as a module, choose M here: the
 	  module will be called touchit213.

+config TOUCHSCREEN_TSC2007
+	tristate "TSC2007 based touchscreens"
+	depends on I2C
+	help
+	  Say Y here if you have a TSC2007 based touchscreens.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called tsc2007.
+
 endif
diff --git a/drivers/input/touchscreen/Makefile
b/drivers/input/touchscreen/Makefile
index 15cf290..824999c 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -31,3 +31,4 @@ wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705)	+= wm9705.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9712)	+= wm9712.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9713)	+= wm9713.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)	+= mainstone-wm97xx.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 0000000..44b68c1
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -0,0 +1,378 @@
+/*
+ * drivers/input/touchscreen/tsc2007.c
+ *
+ * Copyright (c) 2008 MtekVision Co., Ltd.
+ * 	Kwangwoo Lee <kwlee@mtekvision.com>
+ *
+ * Using code from:
+ *  - 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/module.h>
+#include <linux/hrtimer.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/i2c/tsc2007.h>
+
+#define TS_POLL_DELAY	(10 * 1000)	/* ns delay before the first sample */
+#define TS_POLL_PERIOD	(5 * 1000)	/* ns delay between samples */
+
+#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
+#define TSC2007_MEASURE_AUX		(0x2 << 4)
+#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
+#define TSC2007_ACTIVATE_XN		(0x8 << 4)
+#define TSC2007_ACTIVATE_YN		(0x9 << 4)
+#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
+#define TSC2007_SETUP			(0xb << 4)
+#define TSC2007_MEASURE_X		(0xc << 4)
+#define TSC2007_MEASURE_Y		(0xd << 4)
+#define TSC2007_MEASURE_Z1		(0xe << 4)
+#define TSC2007_MEASURE_Z2		(0xf << 4)
+
+#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
+#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
+
+#define TSC2007_12BIT			(0x0 << 1)
+#define TSC2007_8BIT			(0x1 << 1)
+
+#define	MAX_12BIT			((1 << 12) - 1)
+
+#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
+
+#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
+#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
+#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
+#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
+#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
+
+struct ts_event {
+	u16	x;
+	u16	y;
+	u16	z1, z2;
+};
+
+struct tsc2007 {
+	struct input_dev	*input;
+	char			phys[32];
+	struct hrtimer		timer;
+	struct ts_event		tc;
+
+	struct i2c_client	*client;
+
+	spinlock_t		lock;
+
+	u16			model;
+	u16			x_plate_ohms;
+
+	unsigned		pendown;
+	int			irq;
+
+	int			(*get_pendown_state)(void);
+	void			(*clear_penirq)(void);
+};
+
+static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
+{
+	s32 data;
+	u16 val;
+
+	data = i2c_smbus_read_word_data(tsc->client, cmd);
+	if (data < 0) {
+		dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
+		return data;
+	}
+
+	/* The protocol and raw data format from i2c interface:
+	 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
+	 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
+	 */
+
+	val = (u16) (data & 0xFFFF);
+	val = be16_to_cpu(val) >> 4;
+
+	dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
+
+	return val;
+}
+
+static void tsc2007_send_event(void *tsc)
+{
+	struct tsc2007	*ts = tsc;
+	u32		rt;
+	u16		x, y, z1, z2;
+
+	x = ts->tc.x;
+	y = ts->tc.y;
+	z1 = ts->tc.z1;
+	z2 = ts->tc.z2;
+
+	/* range filtering */
+	if (x == MAX_12BIT)
+		x = 0;
+
+	if (likely(x && z1)) {
+		/* compute touch pressure resistance using equation #1 */
+		rt = z2;
+		rt -= z1;
+		rt *= x;
+		rt *= ts->x_plate_ohms;
+		rt /= z1;
+		rt = (rt + 2047) >> 12;
+	} else
+		rt = 0;
+
+	/* Sample found inconsistent by debouncing or pressure is beyond
+	 * the maximum. Don't report it to user space, repeat at least
+	 * once more the measurement
+	 */
+	if (rt > MAX_12BIT) {
+		dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
+
+		hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+			      HRTIMER_MODE_REL);
+		return;
+	}
+
+	/* NOTE: We can't rely on the pressure to determine the pen down
+	 * state, even this controller has a pressure sensor.  The pressure
+	 * value can fluctuate for quite a while after lifting the pen and
+	 * in some cases may not even settle at the expected value.
+	 *
+	 * The only safe way to check for the pen up condition is in the
+	 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
+	 */
+	if (rt) {
+		struct input_dev *input = ts->input;
+
+		if (!ts->pendown) {
+			dev_dbg(&ts->client->dev, "DOWN\n");
+
+			input_report_key(input, BTN_TOUCH, 1);
+			ts->pendown = 1;
+		}
+
+		input_report_abs(input, ABS_X, x);
+		input_report_abs(input, ABS_Y, y);
+		input_report_abs(input, ABS_PRESSURE, rt);
+
+		input_sync(input);
+
+		dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
+			x, y, rt);
+	}
+
+	hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+			HRTIMER_MODE_REL);
+}
+
+static int tsc2007_read_values(struct tsc2007 *tsc)
+{
+	/* y- still on; turn on only y+ (and ADC) */
+	tsc->tc.y = tsc2007_xfer(tsc, READ_Y);
+
+	/* turn y- off, x+ on, then leave in lowpower */
+	tsc->tc.x = tsc2007_xfer(tsc, READ_X);
+
+	/* turn y+ off, x- on; we'll use formula #1 */
+	tsc->tc.z1 = tsc2007_xfer(tsc, READ_Z1);
+	tsc->tc.z2 = tsc2007_xfer(tsc, READ_Z2);
+
+	/* power down */
+	tsc2007_xfer(tsc, PWRDOWN);
+	return 0;
+}
+
+static enum hrtimer_restart tsc2007_timer(struct hrtimer *handle)
+{
+	struct tsc2007	*ts = container_of(handle, struct tsc2007, timer);
+
+	spin_lock_irq(&ts->lock);
+
+	if (unlikely(!ts->get_pendown_state() && ts->pendown)) {
+		struct input_dev *input = ts->input;
+
+		dev_dbg(&ts->client->dev, "UP\n");
+
+		input_report_key(input, BTN_TOUCH, 0);
+		input_report_abs(input, ABS_PRESSURE, 0);
+		input_sync(input);
+
+		ts->pendown = 0;
+		enable_irq(ts->irq);
+	} else {
+		/* pen is still down, continue with the measurement */
+		dev_dbg(&ts->client->dev, "pen is still down\n");
+
+		tsc2007_read_values(ts);
+		tsc2007_send_event(ts);
+	}
+
+	spin_unlock_irq(&ts->lock);
+	return HRTIMER_NORESTART;
+}
+
+static irqreturn_t tsc2007_irq(int irq, void *handle)
+{
+	struct tsc2007 *ts = handle;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ts->lock, flags);
+	if (likely(ts->get_pendown_state())) {
+		disable_irq(ts->irq);
+		hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
+					HRTIMER_MODE_REL);
+	}
+
+	if (ts->clear_penirq)
+		ts->clear_penirq();
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static int tsc2007_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct tsc2007		*ts;
+	struct tsc2007_platform_data *pdata;
+	struct input_dev	*input_dev;
+	int			err;
+
+	pdata = client->dev.platform_data;
+	if (pdata == NULL) {
+		dev_err(&client->dev, "platform data is required!\n");
+		return -EINVAL;
+	}
+
+	if (!i2c_check_functionality(client->adapter,
+		I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -EIO;
+
+	ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!ts || !input_dev) {
+		err = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	ts->client = client;
+	i2c_set_clientdata(client, ts);
+
+	ts->input = input_dev;
+
+	hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	ts->timer.function = tsc2007_timer;
+
+	spin_lock_init(&ts->lock);
+
+	ts->model             = pdata->model;
+	ts->x_plate_ohms      = pdata->x_plate_ohms;
+	ts->get_pendown_state = pdata->get_pendown_state;
+	ts->clear_penirq      = pdata->clear_penirq;
+
+	pdata->init_platform_hw();
+
+	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", client->dev.bus_id);
+
+	input_dev->name = "TSC2007 Touchscreen";
+	input_dev->phys = ts->phys;
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
+	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
+
+	tsc2007_read_values(ts);
+
+	ts->irq = client->irq;
+	err = request_irq(ts->irq, tsc2007_irq, 0,
+			client->dev.driver->name, ts);
+	if (err < 0) {
+		dev_err(&client->dev, "irq %d busy?\n", ts->irq);
+		goto err_free_mem;
+	}
+
+	err = input_register_device(input_dev);
+	if (err)
+		goto err_free_irq;
+
+	dev_info(&client->dev, "registered with irq (%d)\n", ts->irq);
+
+	return 0;
+
+ err_free_irq:
+	free_irq(ts->irq, ts);
+ err_free_mem:
+	input_free_device(input_dev);
+	kfree(ts);
+	return err;
+}
+
+static int tsc2007_remove(struct i2c_client *client)
+{
+	struct tsc2007	*ts = i2c_get_clientdata(client);
+	struct tsc2007_platform_data *pdata;
+
+	pdata = client->dev.platform_data;
+	pdata->exit_platform_hw();
+
+	input_unregister_device(ts->input);
+	free_irq(ts->irq, ts);
+	kfree(ts);
+
+	dev_info(&client->dev, "unregistered\n");
+	return 0;
+}
+
+static struct i2c_device_id tsc2007_idtable[] = {
+	{ "tsc2007", 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
+
+static struct i2c_driver tsc2007_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "tsc2007"
+	},
+	.id_table	= tsc2007_idtable,
+	.probe		= tsc2007_probe,
+	.remove		= tsc2007_remove,
+};
+
+static int __init tsc2007_init(void)
+{
+	return i2c_add_driver(&tsc2007_driver);
+}
+
+static void __exit tsc2007_exit(void)
+{
+	i2c_del_driver(&tsc2007_driver);
+}
+
+module_init(tsc2007_init);
+module_exit(tsc2007_exit);
+
+MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
+MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/i2c/tsc2007.h b/include/linux/i2c/tsc2007.h
new file mode 100644
index 0000000..c6361fb
--- /dev/null
+++ b/include/linux/i2c/tsc2007.h
@@ -0,0 +1,17 @@
+#ifndef __LINUX_I2C_TSC2007_H
+#define __LINUX_I2C_TSC2007_H
+
+/* linux/i2c/tsc2007.h */
+
+struct tsc2007_platform_data {
+	u16	model;				/* 2007. */
+	u16	x_plate_ohms;
+
+	int	(*get_pendown_state)(void);
+	void	(*clear_penirq)(void);		/* If needed, clear 2nd level
+						   interrupt source */
+	int	(*init_platform_hw)(void);
+	void	(*exit_platform_hw)(void);
+};
+
+#endif
-- 
1.5.6.5

Re: + input-add-tsc2007-based-touchscreen-driver.patch added to -mm tree

[Jean Delvare]

On Mon, 8 Dec 2008 14:35:59 +0900, Kwangwoo Lee wrote:
> From d5258e21e38e38e4128112844f24621ffb1c1e86 Mon Sep 17 00:00:00 2001
> From: Kwangwoo Lee <kwangwoo.lee@gmail.com>
> Date: Mon, 8 Dec 2008 13:42:14 +0900
> Subject: [PATCH] Add tsc2007 based touchscreen driver.
> 
> corrected some parts following in helpful comments:
> Remove unnecessary headers and variables.
> Use i2c_smbus_read_word_data() to prevent race condition.
> Fix i2c_check_functionality() argument correctly.
> 
> Signed-off-by: Kwangwoo Lee <kwangwoo.lee@gmail.com>

Looks much better, thanks. Just one thing:

> +static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
> +{
> +	s32 data;
> +	u16 val;
> +
> +	data = i2c_smbus_read_word_data(tsc->client, cmd);
> +	if (data < 0) {
> +		dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
> +		return data;
> +	}
> +
> +	/* The protocol and raw data format from i2c interface:
> +	 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
> +	 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
> +	 */
> +
> +	val = (u16) (data & 0xFFFF);

These masking and cast are unnecessary. i2c_smbus_read_word_data()
returns a 16-bit value already.

> +	val = be16_to_cpu(val) >> 4;

I don't think this is correct. The SMBus read word protocol says that
the LSB goes first on the wire. If your chip sends the MSB first (and
in fast almost all I2C/SMBus chips I know, do that) then you need to
swap the bytes in the driver, but this must be done independently of
the CPU endianness! This means that you should use swab16() rather than
be16_to_cpu().

So I believe that what you really want is:

#include <linux/swab.h>

	val = swab16(data) >> 4;

> +
> +	dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
> +
> +	return val;
> +}

The rest looks OK.

-- 
Jean Delvare

Re: + input-add-tsc2007-based-touchscreen-driver.patch added to -mm tree

[Kwangwoo Lee]

>From efd6b79f2e0220e41f95e5b6acf5aa4fc0b0339a Mon Sep 17 00:00:00 2001
From: Kwangwoo Lee <kwangwoo.lee@gmail.com>
Date: Mon, 8 Dec 2008 18:26:18 +0900
Subject: [PATCH] input: add tsc2007 based touchscreen driver.
 Use swap16() instead of be16_to_cpu() in tsc2007_xfer().

Thank you very much for all your comments regaring this driver.

Signed-off-by: Kwangwoo Lee <kwangwoo.lee@gmail.com>
---
 drivers/input/touchscreen/Kconfig   |    9 +
 drivers/input/touchscreen/Makefile  |    1 +
 drivers/input/touchscreen/tsc2007.c |  376 +++++++++++++++++++++++++++++++++++
 include/linux/i2c/tsc2007.h         |   17 ++
 4 files changed, 403 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/touchscreen/tsc2007.c
 create mode 100644 include/linux/i2c/tsc2007.h

diff --git a/drivers/input/touchscreen/Kconfig
b/drivers/input/touchscreen/Kconfig
index 3d1ab8f..78abdfb 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -376,4 +376,13 @@ config TOUCHSCREEN_TOUCHIT213
 	  To compile this driver as a module, choose M here: the
 	  module will be called touchit213.

+config TOUCHSCREEN_TSC2007
+	tristate "TSC2007 based touchscreens"
+	depends on I2C
+	help
+	  Say Y here if you have a TSC2007 based touchscreens.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called tsc2007.
+
 endif
diff --git a/drivers/input/touchscreen/Makefile
b/drivers/input/touchscreen/Makefile
index 15cf290..824999c 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -31,3 +31,4 @@ wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705)	+= wm9705.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9712)	+= wm9712.o
 wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9713)	+= wm9713.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)	+= mainstone-wm97xx.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 0000000..e30cc25
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -0,0 +1,376 @@
+/*
+ * drivers/input/touchscreen/tsc2007.c
+ *
+ * Copyright (c) 2008 MtekVision Co., Ltd.
+ * 	Kwangwoo Lee <kwlee@mtekvision.com>
+ *
+ * Using code from:
+ *  - 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/module.h>
+#include <linux/hrtimer.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/i2c/tsc2007.h>
+
+#define TS_POLL_DELAY	(10 * 1000)	/* ns delay before the first sample */
+#define TS_POLL_PERIOD	(5 * 1000)	/* ns delay between samples */
+
+#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
+#define TSC2007_MEASURE_AUX		(0x2 << 4)
+#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
+#define TSC2007_ACTIVATE_XN		(0x8 << 4)
+#define TSC2007_ACTIVATE_YN		(0x9 << 4)
+#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
+#define TSC2007_SETUP			(0xb << 4)
+#define TSC2007_MEASURE_X		(0xc << 4)
+#define TSC2007_MEASURE_Y		(0xd << 4)
+#define TSC2007_MEASURE_Z1		(0xe << 4)
+#define TSC2007_MEASURE_Z2		(0xf << 4)
+
+#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
+#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
+
+#define TSC2007_12BIT			(0x0 << 1)
+#define TSC2007_8BIT			(0x1 << 1)
+
+#define	MAX_12BIT			((1 << 12) - 1)
+
+#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
+
+#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
+#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
+#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
+#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
+#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
+
+struct ts_event {
+	u16	x;
+	u16	y;
+	u16	z1, z2;
+};
+
+struct tsc2007 {
+	struct input_dev	*input;
+	char			phys[32];
+	struct hrtimer		timer;
+	struct ts_event		tc;
+
+	struct i2c_client	*client;
+
+	spinlock_t		lock;
+
+	u16			model;
+	u16			x_plate_ohms;
+
+	unsigned		pendown;
+	int			irq;
+
+	int			(*get_pendown_state)(void);
+	void			(*clear_penirq)(void);
+};
+
+static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
+{
+	s32 data;
+	u16 val;
+
+	data = i2c_smbus_read_word_data(tsc->client, cmd);
+	if (data < 0) {
+		dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
+		return data;
+	}
+
+	/* The protocol and raw data format from i2c interface:
+	 * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
+	 * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
+	 */
+	val = swab16(data) >> 4;
+
+	dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
+
+	return val;
+}
+
+static void tsc2007_send_event(void *tsc)
+{
+	struct tsc2007	*ts = tsc;
+	u32		rt;
+	u16		x, y, z1, z2;
+
+	x = ts->tc.x;
+	y = ts->tc.y;
+	z1 = ts->tc.z1;
+	z2 = ts->tc.z2;
+
+	/* range filtering */
+	if (x == MAX_12BIT)
+		x = 0;
+
+	if (likely(x && z1)) {
+		/* compute touch pressure resistance using equation #1 */
+		rt = z2;
+		rt -= z1;
+		rt *= x;
+		rt *= ts->x_plate_ohms;
+		rt /= z1;
+		rt = (rt + 2047) >> 12;
+	} else
+		rt = 0;
+
+	/* Sample found inconsistent by debouncing or pressure is beyond
+	 * the maximum. Don't report it to user space, repeat at least
+	 * once more the measurement
+	 */
+	if (rt > MAX_12BIT) {
+		dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
+
+		hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+			      HRTIMER_MODE_REL);
+		return;
+	}
+
+	/* NOTE: We can't rely on the pressure to determine the pen down
+	 * state, even this controller has a pressure sensor.  The pressure
+	 * value can fluctuate for quite a while after lifting the pen and
+	 * in some cases may not even settle at the expected value.
+	 *
+	 * The only safe way to check for the pen up condition is in the
+	 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
+	 */
+	if (rt) {
+		struct input_dev *input = ts->input;
+
+		if (!ts->pendown) {
+			dev_dbg(&ts->client->dev, "DOWN\n");
+
+			input_report_key(input, BTN_TOUCH, 1);
+			ts->pendown = 1;
+		}
+
+		input_report_abs(input, ABS_X, x);
+		input_report_abs(input, ABS_Y, y);
+		input_report_abs(input, ABS_PRESSURE, rt);
+
+		input_sync(input);
+
+		dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
+			x, y, rt);
+	}
+
+	hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+			HRTIMER_MODE_REL);
+}
+
+static int tsc2007_read_values(struct tsc2007 *tsc)
+{
+	/* y- still on; turn on only y+ (and ADC) */
+	tsc->tc.y = tsc2007_xfer(tsc, READ_Y);
+
+	/* turn y- off, x+ on, then leave in lowpower */
+	tsc->tc.x = tsc2007_xfer(tsc, READ_X);
+
+	/* turn y+ off, x- on; we'll use formula #1 */
+	tsc->tc.z1 = tsc2007_xfer(tsc, READ_Z1);
+	tsc->tc.z2 = tsc2007_xfer(tsc, READ_Z2);
+
+	/* power down */
+	tsc2007_xfer(tsc, PWRDOWN);
+	return 0;
+}
+
+static enum hrtimer_restart tsc2007_timer(struct hrtimer *handle)
+{
+	struct tsc2007	*ts = container_of(handle, struct tsc2007, timer);
+
+	spin_lock_irq(&ts->lock);
+
+	if (unlikely(!ts->get_pendown_state() && ts->pendown)) {
+		struct input_dev *input = ts->input;
+
+		dev_dbg(&ts->client->dev, "UP\n");
+
+		input_report_key(input, BTN_TOUCH, 0);
+		input_report_abs(input, ABS_PRESSURE, 0);
+		input_sync(input);
+
+		ts->pendown = 0;
+		enable_irq(ts->irq);
+	} else {
+		/* pen is still down, continue with the measurement */
+		dev_dbg(&ts->client->dev, "pen is still down\n");
+
+		tsc2007_read_values(ts);
+		tsc2007_send_event(ts);
+	}
+
+	spin_unlock_irq(&ts->lock);
+	return HRTIMER_NORESTART;
+}
+
+static irqreturn_t tsc2007_irq(int irq, void *handle)
+{
+	struct tsc2007 *ts = handle;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ts->lock, flags);
+	if (likely(ts->get_pendown_state())) {
+		disable_irq(ts->irq);
+		hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
+					HRTIMER_MODE_REL);
+	}
+
+	if (ts->clear_penirq)
+		ts->clear_penirq();
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static int tsc2007_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct tsc2007		*ts;
+	struct tsc2007_platform_data *pdata;
+	struct input_dev	*input_dev;
+	int			err;
+
+	pdata = client->dev.platform_data;
+	if (pdata == NULL) {
+		dev_err(&client->dev, "platform data is required!\n");
+		return -EINVAL;
+	}
+
+	if (!i2c_check_functionality(client->adapter,
+		I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -EIO;
+
+	ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!ts || !input_dev) {
+		err = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	ts->client = client;
+	i2c_set_clientdata(client, ts);
+
+	ts->input = input_dev;
+
+	hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	ts->timer.function = tsc2007_timer;
+
+	spin_lock_init(&ts->lock);
+
+	ts->model             = pdata->model;
+	ts->x_plate_ohms      = pdata->x_plate_ohms;
+	ts->get_pendown_state = pdata->get_pendown_state;
+	ts->clear_penirq      = pdata->clear_penirq;
+
+	pdata->init_platform_hw();
+
+	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", client->dev.bus_id);
+
+	input_dev->name = "TSC2007 Touchscreen";
+	input_dev->phys = ts->phys;
+
+	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+	input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
+	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
+
+	tsc2007_read_values(ts);
+
+	ts->irq = client->irq;
+	err = request_irq(ts->irq, tsc2007_irq, 0,
+			client->dev.driver->name, ts);
+	if (err < 0) {
+		dev_err(&client->dev, "irq %d busy?\n", ts->irq);
+		goto err_free_mem;
+	}
+
+	err = input_register_device(input_dev);
+	if (err)
+		goto err_free_irq;
+
+	dev_info(&client->dev, "registered with irq (%d)\n", ts->irq);
+
+	return 0;
+
+ err_free_irq:
+	free_irq(ts->irq, ts);
+ err_free_mem:
+	input_free_device(input_dev);
+	kfree(ts);
+	return err;
+}
+
+static int tsc2007_remove(struct i2c_client *client)
+{
+	struct tsc2007	*ts = i2c_get_clientdata(client);
+	struct tsc2007_platform_data *pdata;
+
+	pdata = client->dev.platform_data;
+	pdata->exit_platform_hw();
+
+	input_unregister_device(ts->input);
+	free_irq(ts->irq, ts);
+	kfree(ts);
+
+	dev_info(&client->dev, "unregistered\n");
+	return 0;
+}
+
+static struct i2c_device_id tsc2007_idtable[] = {
+	{ "tsc2007", 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
+
+static struct i2c_driver tsc2007_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "tsc2007"
+	},
+	.id_table	= tsc2007_idtable,
+	.probe		= tsc2007_probe,
+	.remove		= tsc2007_remove,
+};
+
+static int __init tsc2007_init(void)
+{
+	return i2c_add_driver(&tsc2007_driver);
+}
+
+static void __exit tsc2007_exit(void)
+{
+	i2c_del_driver(&tsc2007_driver);
+}
+
+module_init(tsc2007_init);
+module_exit(tsc2007_exit);
+
+MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
+MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/i2c/tsc2007.h b/include/linux/i2c/tsc2007.h
new file mode 100644
index 0000000..c6361fb
--- /dev/null
+++ b/include/linux/i2c/tsc2007.h
@@ -0,0 +1,17 @@
+#ifndef __LINUX_I2C_TSC2007_H
+#define __LINUX_I2C_TSC2007_H
+
+/* linux/i2c/tsc2007.h */
+
+struct tsc2007_platform_data {
+	u16	model;				/* 2007. */
+	u16	x_plate_ohms;
+
+	int	(*get_pendown_state)(void);
+	void	(*clear_penirq)(void);		/* If needed, clear 2nd level
+						   interrupt source */
+	int	(*init_platform_hw)(void);
+	void	(*exit_platform_hw)(void);
+};
+
+#endif
-- 
1.5.6.5

Re: + input-add-tsc2007-based-touchscreen-driver.patch added to -mm tree

[Jean Delvare]

On Mon, 8 Dec 2008 18:36:43 +0900, Kwangwoo Lee wrote:
> From efd6b79f2e0220e41f95e5b6acf5aa4fc0b0339a Mon Sep 17 00:00:00 2001
> From: Kwangwoo Lee <kwangwoo.lee@gmail.com>
> Date: Mon, 8 Dec 2008 18:26:18 +0900
> Subject: [PATCH] input: add tsc2007 based touchscreen driver.
>  Use swap16() instead of be16_to_cpu() in tsc2007_xfer().
> 
> Thank you very much for all your comments regaring this driver.
> 
> Signed-off-by: Kwangwoo Lee <kwangwoo.lee@gmail.com>

i2c part:
Acked-by: Jean Delvare <khali@linux-fr.org>


> ---
>  drivers/input/touchscreen/Kconfig   |    9 +
>  drivers/input/touchscreen/Makefile  |    1 +
>  drivers/input/touchscreen/tsc2007.c |  376 +++++++++++++++++++++++++++++++++++
>  include/linux/i2c/tsc2007.h         |   17 ++
>  4 files changed, 403 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/input/touchscreen/tsc2007.c
>  create mode 100644 include/linux/i2c/tsc2007.h
> (...)

-- 
Jean Delvare