[PATCH 2/4] Input: ad7879 - split bus logic out

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

From: Mike Frysinger <vapier@gentoo.org>

The ad7879 driver is using the old bus method of only supporting one at a
time (I2C or SPI).  So refactor it like the other input drivers that
support multiple busses simultaneously.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---

 drivers/input/touchscreen/ad7879-i2c.c |  140 +++++++++
 drivers/input/touchscreen/ad7879-spi.c |  190 ++++++++++++
 drivers/input/touchscreen/ad7879.c     |  495 +++++++-------------------------
 drivers/input/touchscreen/ad7879.h     |   30 ++
 4 files changed, 461 insertions(+), 394 deletions(-)
 create mode 100644 drivers/input/touchscreen/ad7879-i2c.c
 create mode 100644 drivers/input/touchscreen/ad7879-spi.c
 create mode 100644 drivers/input/touchscreen/ad7879.h

diff --git a/drivers/input/touchscreen/ad7879-i2c.c b/drivers/input/touchscreen/ad7879-i2c.c
new file mode 100644
index 0000000..41b32cb
--- /dev/null
+++ b/drivers/input/touchscreen/ad7879-i2c.c
@@ -0,0 +1,140 @@
+/*
+ * AD7879-1/AD7889-1 touchscreen (I2C bus)
+ *
+ * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/input.h>	/* BUS_I2C */
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include "ad7879.h"
+
+#define AD7879_DEVID		0x79	/* AD7879-1/AD7889-1 */
+
+#ifdef CONFIG_PM
+static int ad7879_i2c_suspend(struct i2c_client *client, pm_message_t message)
+{
+	struct ad7879 *ts = i2c_get_clientdata(client);
+
+	ad7879_disable(ts);
+
+	return 0;
+}
+
+static int ad7879_i2c_resume(struct i2c_client *client)
+{
+	struct ad7879 *ts = i2c_get_clientdata(client);
+
+	ad7879_enable(ts);
+
+	return 0;
+}
+#else
+# define ad7879_i2c_suspend NULL
+# define ad7879_i2c_resume  NULL
+#endif
+
+/* All registers are word-sized.
+ * AD7879 uses a high-byte first convention.
+ */
+static int ad7879_i2c_read(struct device *dev, u8 reg)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	return swab16(i2c_smbus_read_word_data(client, reg));
+}
+
+static int ad7879_i2c_multi_read(struct device *dev,
+				 u8 first_reg, u8 count, u16 *buf)
+{
+	u8 idx;
+
+	for (idx = 0; idx < count; ++idx)
+		buf[idx] = ad7879_i2c_read(dev, first_reg + idx);
+
+	return 0;
+}
+
+static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	return i2c_smbus_write_word_data(client, reg, swab16(val));
+}
+
+static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
+	.bustype	= BUS_I2C,
+	.read		= ad7879_i2c_read,
+	.multi_read	= ad7879_i2c_multi_read,
+	.write		= ad7879_i2c_write,
+};
+
+static int __devinit ad7879_i2c_probe(struct i2c_client *client,
+				      const struct i2c_device_id *id)
+{
+	struct ad7879 *ts;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_WORD_DATA)) {
+		dev_err(&client->dev, "SMBUS Word Data not Supported\n");
+		return -EIO;
+	}
+
+	ts = ad7879_probe(&client->dev, client->irq, AD7879_DEVID,
+			  &ad7879_i2c_bus_ops);
+	if (IS_ERR(ts))
+		return PTR_ERR(ts);
+
+	i2c_set_clientdata(client, ts);
+
+	return 0;
+}
+
+static int __devexit ad7879_i2c_remove(struct i2c_client *client)
+{
+	struct ad7879 *ts = i2c_get_clientdata(client);
+
+	ad7879_remove(ts);
+
+	return 0;
+}
+
+static const struct i2c_device_id ad7879_id[] = {
+	{ "ad7879", 0 },
+	{ "ad7889", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ad7879_id);
+
+static struct i2c_driver ad7879_i2c_driver = {
+	.driver = {
+		.name	= "ad7879",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad7879_i2c_probe,
+	.remove		= __devexit_p(ad7879_i2c_remove),
+	.suspend	= ad7879_i2c_suspend,
+	.resume		= ad7879_i2c_resume,
+	.id_table	= ad7879_id,
+};
+
+static int __init ad7879_i2c_init(void)
+{
+	return i2c_add_driver(&ad7879_i2c_driver);
+}
+module_init(ad7879_i2c_init);
+
+static void __exit ad7879_i2c_exit(void)
+{
+	i2c_del_driver(&ad7879_i2c_driver);
+}
+module_exit(ad7879_i2c_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("i2c:ad7879");
diff --git a/drivers/input/touchscreen/ad7879-spi.c b/drivers/input/touchscreen/ad7879-spi.c
new file mode 100644
index 0000000..cd12dac
--- /dev/null
+++ b/drivers/input/touchscreen/ad7879-spi.c
@@ -0,0 +1,190 @@
+/*
+ * AD7879/AD7889 touchscreen (SPI bus)
+ *
+ * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/input.h>	/* BUS_SPI */
+#include <linux/spi/spi.h>
+
+#include "ad7879.h"
+
+#define AD7879_DEVID		0x7A	/* AD7879/AD7889 */
+
+#define MAX_SPI_FREQ_HZ      5000000
+#define AD7879_CMD_MAGIC     0xE000
+#define AD7879_CMD_READ      (1 << 10)
+#define AD7879_CMD(reg)      (AD7879_CMD_MAGIC | ((reg) & 0xF))
+#define AD7879_WRITECMD(reg) (AD7879_CMD(reg))
+#define AD7879_READCMD(reg)  (AD7879_CMD(reg) | AD7879_CMD_READ)
+
+#ifdef CONFIG_PM
+static int ad7879_spi_suspend(struct spi_device *spi, pm_message_t message)
+{
+	struct ad7879 *ts = spi_get_drvdata(spi);
+
+	ad7879_disable(ts);
+
+	return 0;
+}
+
+static int ad7879_spi_resume(struct spi_device *spi)
+{
+	struct ad7879 *ts = spi_get_drvdata(spi);
+
+	ad7879_enable(ts);
+
+	return 0;
+}
+#else
+# define ad7879_spi_suspend NULL
+# define ad7879_spi_resume  NULL
+#endif
+
+/*
+ * ad7879_read/write are only used for initial setup and for sysfs controls.
+ * The main traffic is done in ad7879_collect().
+ */
+
+static int ad7879_spi_xfer(struct spi_device *spi,
+			   u16 cmd, u8 count, u16 *tx_buf, u16 *rx_buf)
+{
+	struct spi_message msg;
+	struct spi_transfer *xfers;
+	void *spi_data;
+	u16 *command;
+	u16 *_rx_buf = _rx_buf; /* shut gcc up */
+	u8 idx;
+	int ret;
+
+	xfers = spi_data = kzalloc(sizeof(*xfers) * (count + 2), GFP_KERNEL);
+	if (!spi_data)
+		return -ENOMEM;
+
+	spi_message_init(&msg);
+
+	command = spi_data;
+	command[0] = cmd;
+	if (count == 1) {
+		/* ad7879_spi_{read,write} gave us buf on stack */
+		command[1] = *tx_buf;
+		tx_buf = &command[1];
+		_rx_buf = rx_buf;
+		rx_buf = &command[2];
+	}
+
+	++xfers;
+	xfers[0].tx_buf = command;
+	xfers[0].len = 2;
+	spi_message_add_tail(&xfers[0], &msg);
+	++xfers;
+
+	for (idx = 0; idx < count; ++idx) {
+		if (rx_buf)
+			xfers[idx].rx_buf = &rx_buf[idx];
+		if (tx_buf)
+			xfers[idx].tx_buf = &tx_buf[idx];
+		xfers[idx].len = 2;
+		spi_message_add_tail(&xfers[idx], &msg);
+	}
+
+	ret = spi_sync(spi, &msg);
+
+	if (count == 1)
+		_rx_buf[0] = command[2];
+
+	kfree(spi_data);
+
+	return ret;
+}
+
+static int ad7879_spi_multi_read(struct device *dev,
+				 u8 first_reg, u8 count, u16 *buf)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	return ad7879_spi_xfer(spi, AD7879_READCMD(first_reg), count, NULL, buf);
+}
+
+static int ad7879_spi_read(struct device *dev, u8 reg)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	u16 ret, dummy;
+
+	return ad7879_spi_xfer(spi, AD7879_READCMD(reg), 1, &dummy, &ret) ? : ret;
+}
+
+static int ad7879_spi_write(struct device *dev, u8 reg, u16 val)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	u16 dummy;
+
+	return ad7879_spi_xfer(spi, AD7879_WRITECMD(reg), 1, &val, &dummy);
+}
+
+static const struct ad7879_bus_ops ad7879_spi_bus_ops = {
+	.bustype	= BUS_SPI,
+	.read		= ad7879_spi_read,
+	.multi_read	= ad7879_spi_multi_read,
+	.write		= ad7879_spi_write,
+};
+
+static int __devinit ad7879_spi_probe(struct spi_device *spi)
+{
+	struct ad7879 *ts;
+
+	/* don't exceed max specified SPI CLK frequency */
+	if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
+		dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
+		return -EINVAL;
+	}
+
+	ts = ad7879_probe(&spi->dev, spi->irq, AD7879_DEVID, &ad7879_spi_bus_ops);
+	if (IS_ERR(ts))
+		return PTR_ERR(ts);
+
+	spi_set_drvdata(spi, ts);
+
+	return 0;
+}
+
+static int __devexit ad7879_spi_remove(struct spi_device *spi)
+{
+	struct ad7879 *ts = spi_get_drvdata(spi);
+
+	ad7879_remove(ts);
+	spi_set_drvdata(spi, NULL);
+
+	return 0;
+}
+
+static struct spi_driver ad7879_spi_driver = {
+	.driver = {
+		.name	= "ad7879",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad7879_spi_probe,
+	.remove		= __devexit_p(ad7879_spi_remove),
+	.suspend	= ad7879_spi_suspend,
+	.resume		= ad7879_spi_resume,
+};
+
+static int __init ad7879_spi_init(void)
+{
+	return spi_register_driver(&ad7879_spi_driver);
+}
+module_init(ad7879_spi_init);
+
+static void __exit ad7879_spi_exit(void)
+{
+	spi_unregister_driver(&ad7879_spi_driver);
+}
+module_exit(ad7879_spi_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:ad7879");
diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
index f947457..59a794c 100644
--- a/drivers/input/touchscreen/ad7879.c
+++ b/drivers/input/touchscreen/ad7879.c
@@ -1,25 +1,9 @@
 /*
- * Copyright (C) 2008-2009 Michael Hennerich, Analog Devices Inc.
+ * AD7879/AD7889 based touchscreen and GPIO driver
  *
- * Description:	AD7879/AD7889 based touchscreen, and GPIO driver
- *		(I2C/SPI Interface)
+ * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
  *
- * Bugs:        Enter bugs at http://blackfin.uclinux.org/
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see the file COPYING, or write
- * to the Free Software Foundation, Inc.,
- * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ * Licensed under the GPL-2 or later.
  *
  * History:
  * Copyright (c) 2005 David Brownell
@@ -49,6 +33,7 @@
 #include <linux/gpio.h>
 
 #include <linux/spi/ad7879.h>
+#include "ad7879.h"
 
 #define AD7879_REG_ZEROS		0
 #define AD7879_REG_CTRL1		1
@@ -119,29 +104,18 @@ enum {
 #define	MAX_12BIT			((1<<12)-1)
 #define	TS_PEN_UP_TIMEOUT		msecs_to_jiffies(50)
 
-#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
-#define AD7879_DEVID		0x7A
-typedef struct spi_device	bus_device;
-#elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
-#define AD7879_DEVID		0x79
-typedef struct i2c_client	bus_device;
-#endif
-
 struct ad7879 {
-	bus_device		*bus;
+	const struct ad7879_bus_ops *bops;
+
+	struct device		*dev;
 	struct input_dev	*input;
 	struct timer_list	timer;
 #ifdef CONFIG_GPIOLIB
 	struct gpio_chip	gc;
 #endif
+	unsigned int		irq;
 	struct mutex		mutex;
 	bool			disabled;	/* P: mutex */
-
-#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
-	struct spi_message	msg;
-	struct spi_transfer	xfer[AD7879_NR_SENSE + 1];
-	u16			cmd;
-#endif
 	u16			conversion_data[AD7879_NR_SENSE];
 	char			phys[32];
 	u8			first_conversion_delay;
@@ -156,9 +130,20 @@ struct ad7879 {
 	u16			cmd_crtl3;
 };
 
-static int ad7879_read(bus_device *, u8);
-static int ad7879_write(bus_device *, u8, u16);
-static void ad7879_collect(struct ad7879 *);
+static int ad7879_read(struct ad7879 *ts, u8 reg)
+{
+	return ts->bops->read(ts->dev, reg);
+}
+
+static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
+{
+	return ts->bops->multi_read(ts->dev, first_reg, count, buf);
+}
+
+static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
+{
+	return ts->bops->write(ts->dev, reg, val);
+}
 
 static void ad7879_report(struct ad7879 *ts)
 {
@@ -173,12 +158,14 @@ static void ad7879_report(struct ad7879 *ts)
 
 	/*
 	 * The samples processed here are already preprocessed by the AD7879.
-	 * The preprocessing function consists of a median and an averaging filter.
-	 * The combination of these two techniques provides a robust solution,
-	 * discarding the spurious noise in the signal and keeping only the data of interest.
-	 * The size of both filters is programmable. (dev.platform_data, see linux/spi/ad7879.h)
-	 * Other user-programmable conversion controls include variable acquisition time,
-	 * and first conversion delay. Up to 16 averages can be taken per conversion.
+	 * The preprocessing function consists of a median and an averaging
+	 * filter.  The combination of these two techniques provides a robust
+	 * solution, discarding the spurious noise in the signal and keeping
+	 * only the data of interest.  The size of both filters is
+	 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
+	 * user-programmable conversion controls include variable acquisition
+	 * time, and first conversion delay. Up to 16 averages can be taken
+	 * per conversion.
 	 */
 
 	if (likely(x && z1)) {
@@ -213,7 +200,7 @@ static irqreturn_t ad7879_irq(int irq, void *handle)
 {
 	struct ad7879 *ts = handle;
 
-	ad7879_collect(ts);
+	ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
 	ad7879_report(ts);
 
 	mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
@@ -223,42 +210,44 @@ static irqreturn_t ad7879_irq(int irq, void *handle)
 
 static void ad7879_setup(struct ad7879 *ts)
 {
-	ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
-	ad7879_write(ts->bus, AD7879_REG_CTRL3, ts->cmd_crtl3);
-	ad7879_write(ts->bus, AD7879_REG_CTRL1, ts->cmd_crtl1);
+	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+	ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
+	ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
 }
 
-static void ad7879_disable(struct ad7879 *ts)
+void ad7879_disable(struct ad7879 *ts)
 {
 	mutex_lock(&ts->mutex);
 
 	if (!ts->disabled) {
 
 		ts->disabled = true;
-		disable_irq(ts->bus->irq);
+		disable_irq(ts->irq);
 
 		if (del_timer_sync(&ts->timer))
 			ad7879_ts_event_release(ts);
 
-		ad7879_write(ts->bus, AD7879_REG_CTRL2,
+		ad7879_write(ts, AD7879_REG_CTRL2,
 			     AD7879_PM(AD7879_PM_SHUTDOWN));
 	}
 
 	mutex_unlock(&ts->mutex);
 }
+EXPORT_SYMBOL(ad7879_disable);
 
-static void ad7879_enable(struct ad7879 *ts)
+void ad7879_enable(struct ad7879 *ts)
 {
 	mutex_lock(&ts->mutex);
 
 	if (ts->disabled) {
 		ad7879_setup(ts);
 		ts->disabled = false;
-		enable_irq(ts->bus->irq);
+		enable_irq(ts->irq);
 	}
 
 	mutex_unlock(&ts->mutex);
 }
+EXPORT_SYMBOL(ad7879_enable);
 
 static ssize_t ad7879_disable_show(struct device *dev,
 				     struct device_attribute *attr, char *buf)
@@ -308,7 +297,7 @@ static int ad7879_gpio_direction_input(struct gpio_chip *chip,
 
 	mutex_lock(&ts->mutex);
 	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
-	err = ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
+	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
 	mutex_unlock(&ts->mutex);
 
 	return err;
@@ -328,7 +317,7 @@ static int ad7879_gpio_direction_output(struct gpio_chip *chip,
 	else
 		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
 
-	err = ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
+	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
 	mutex_unlock(&ts->mutex);
 
 	return err;
@@ -340,7 +329,7 @@ static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
 	u16 val;
 
 	mutex_lock(&ts->mutex);
-	val = ad7879_read(ts->bus, AD7879_REG_CTRL2);
+	val = ad7879_read(ts, AD7879_REG_CTRL2);
 	mutex_unlock(&ts->mutex);
 
 	return !!(val & AD7879_GPIO_DATA);
@@ -357,14 +346,13 @@ static void ad7879_gpio_set_value(struct gpio_chip *chip,
 	else
 		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
 
-	ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
+	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
 	mutex_unlock(&ts->mutex);
 }
 
-static int __devinit ad7879_gpio_add(struct device *dev)
+static int ad7879_gpio_add(struct ad7879 *ts,
+			   const struct ad7879_platform_data *pdata)
 {
-	struct ad7879 *ts = dev_get_drvdata(dev);
-	struct ad7879_platform_data *pdata = dev->platform_data;
 	int ret = 0;
 
 	if (pdata->gpio_export) {
@@ -377,32 +365,26 @@ static int __devinit ad7879_gpio_add(struct device *dev)
 		ts->gc.ngpio = 1;
 		ts->gc.label = "AD7879-GPIO";
 		ts->gc.owner = THIS_MODULE;
-		ts->gc.dev = dev;
+		ts->gc.dev = ts->dev;
 
 		ret = gpiochip_add(&ts->gc);
 		if (ret)
-			dev_err(dev, "failed to register gpio %d\n",
+			dev_err(ts->dev, "failed to register gpio %d\n",
 				ts->gc.base);
 	}
 
 	return ret;
 }
 
-/*
- * We mark ad7879_gpio_remove inline so there is a chance the code
- * gets discarded when not needed. We can't do __devinit/__devexit
- * markup since it is used in both probe and remove methods.
- */
-static inline void ad7879_gpio_remove(struct device *dev)
+static void ad7879_gpio_remove(struct ad7879 *ts)
 {
-	struct ad7879 *ts = dev_get_drvdata(dev);
-	struct ad7879_platform_data *pdata = dev->platform_data;
+	struct ad7879_platform_data *pdata = ts->dev->platform_data;
 	int ret;
 
 	if (pdata->gpio_export) {
 		ret = gpiochip_remove(&ts->gc);
 		if (ret)
-			dev_err(dev, "failed to remove gpio %d\n",
+			dev_err(ts->dev, "failed to remove gpio %d\n",
 				ts->gc.base);
 	}
 }
@@ -417,32 +399,43 @@ static inline void ad7879_gpio_remove(struct device *dev)
 }
 #endif
 
-static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
+struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
+			    const struct ad7879_bus_ops *bops)
 {
+	struct ad7879_platform_data *pdata = dev->platform_data;
+	struct ad7879 *ts;
 	struct input_dev *input_dev;
-	struct ad7879_platform_data *pdata = bus->dev.platform_data;
 	int err;
 	u16 revid;
 
-	if (!bus->irq) {
-		dev_err(&bus->dev, "no IRQ?\n");
-		return -ENODEV;
+	if (!irq) {
+		dev_err(dev, "no IRQ?\n");
+		err = -EINVAL;
+		goto err_out;
 	}
 
 	if (!pdata) {
-		dev_err(&bus->dev, "no platform data?\n");
-		return -ENODEV;
+		dev_err(dev, "no platform data?\n");
+		err = -EINVAL;
+		goto err_out;
 	}
 
+	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
 	input_dev = input_allocate_device();
-	if (!input_dev)
-		return -ENOMEM;
+	if (!ts || !input_dev) {
+		err = -ENOMEM;
+		goto err_free_mem;
+	}
 
+	ts->bops = bops;
+	ts->dev = dev;
 	ts->input = input_dev;
 
 	setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
 	mutex_init(&ts->mutex);
 
+	ts->irq = irq;
+
 	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 	ts->pressure_max = pdata->pressure_max ? : ~0;
 
@@ -452,11 +445,12 @@ static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
 	ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
 	ts->median = pdata->median;
 
-	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&bus->dev));
+	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
 
 	input_dev->name = "AD7879 Touchscreen";
 	input_dev->phys = ts->phys;
-	input_dev->dev.parent = &bus->dev;
+	input_dev->dev.parent = dev;
+	input_dev->id.bustype = bops->bustype;
 
 	__set_bit(EV_ABS, input_dev->evbit);
 	__set_bit(ABS_X, input_dev->absbit);
@@ -474,17 +468,18 @@ static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
 	input_set_abs_params(input_dev, ABS_PRESSURE,
 			pdata->pressure_min, pdata->pressure_max, 0, 0);
 
-	err = ad7879_write(bus, AD7879_REG_CTRL2, AD7879_RESET);
-
+	err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
 	if (err < 0) {
-		dev_err(&bus->dev, "Failed to write %s\n", input_dev->name);
+		dev_err(dev, "Failed to write %s\n", input_dev->name);
 		goto err_free_mem;
 	}
 
-	revid = ad7879_read(bus, AD7879_REG_REVID);
-
-	if ((revid & 0xFF) != AD7879_DEVID) {
-		dev_err(&bus->dev, "Failed to probe %s\n", input_dev->name);
+	revid = ad7879_read(ts, AD7879_REG_REVID);
+	input_dev->id.product = (revid & 0xff);
+	input_dev->id.version = revid >> 8;
+	if (input_dev->id.product != devid) {
+		dev_err(dev, "Failed to probe %s (%x vs %x)\n",
+			input_dev->name, devid, revid);
 		err = -ENODEV;
 		goto err_free_mem;
 	}
@@ -508,19 +503,19 @@ static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
 
 	ad7879_setup(ts);
 
-	err = request_threaded_irq(bus->irq, NULL, ad7879_irq,
+	err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
 				   IRQF_TRIGGER_FALLING,
-				   bus->dev.driver->name, ts);
+				   dev_name(dev), ts);
 	if (err) {
-		dev_err(&bus->dev, "irq %d busy?\n", bus->irq);
+		dev_err(dev, "irq %d busy?\n", ts->irq);
 		goto err_free_mem;
 	}
 
-	err = sysfs_create_group(&bus->dev.kobj, &ad7879_attr_group);
+	err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
 	if (err)
 		goto err_free_irq;
 
-	err = ad7879_gpio_add(&bus->dev);
+	err = ad7879_gpio_add(ts, pdata);
 	if (err)
 		goto err_remove_attr;
 
@@ -528,321 +523,33 @@ static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
 	if (err)
 		goto err_remove_gpio;
 
-	dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n",
-		 revid >> 8, bus->irq);
-
-	return 0;
+	return ts;
 
 err_remove_gpio:
-	ad7879_gpio_remove(&bus->dev);
+	ad7879_gpio_remove(ts);
 err_remove_attr:
-	sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group);
+	sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
 err_free_irq:
-	free_irq(bus->irq, ts);
+	free_irq(ts->irq, ts);
 err_free_mem:
 	input_free_device(input_dev);
-
-	return err;
+	kfree(ts);
+err_out:
+	return ERR_PTR(err);
 }
+EXPORT_SYMBOL(ad7879_probe);
 
-static int __devexit ad7879_destroy(bus_device *bus, struct ad7879 *ts)
+void ad7879_remove(struct ad7879 *ts)
 {
-	ad7879_gpio_remove(&bus->dev);
+	ad7879_gpio_remove(ts);
 	ad7879_disable(ts);
-	sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group);
-	free_irq(ts->bus->irq, ts);
+	sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
+	free_irq(ts->irq, ts);
 	input_unregister_device(ts->input);
-	dev_dbg(&bus->dev, "unregistered touchscreen\n");
-
-	return 0;
-}
-
-#ifdef CONFIG_PM
-static int ad7879_suspend(bus_device *bus, pm_message_t message)
-{
-	struct ad7879 *ts = dev_get_drvdata(&bus->dev);
-
-	ad7879_disable(ts);
-
-	return 0;
-}
-
-static int ad7879_resume(bus_device *bus)
-{
-	struct ad7879 *ts = dev_get_drvdata(&bus->dev);
-
-	ad7879_enable(ts);
-
-	return 0;
-}
-#else
-#define ad7879_suspend NULL
-#define ad7879_resume  NULL
-#endif
-
-#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
-#define MAX_SPI_FREQ_HZ		5000000
-#define AD7879_CMD_MAGIC	0xE000
-#define AD7879_CMD_READ		(1 << 10)
-#define AD7879_WRITECMD(reg)	(AD7879_CMD_MAGIC | (reg & 0xF))
-#define AD7879_READCMD(reg)	(AD7879_CMD_MAGIC | AD7879_CMD_READ | (reg & 0xF))
-
-struct ser_req {
-	u16			command;
-	u16			data;
-	struct spi_message	msg;
-	struct spi_transfer	xfer[2];
-};
-
-/*
- * ad7879_read/write are only used for initial setup and for sysfs controls.
- * The main traffic is done in ad7879_collect().
- */
-
-static int ad7879_read(struct spi_device *spi, u8 reg)
-{
-	struct ser_req *req;
-	int status, ret;
-
-	req = kzalloc(sizeof *req, GFP_KERNEL);
-	if (!req)
-		return -ENOMEM;
-
-	spi_message_init(&req->msg);
-
-	req->command = (u16) AD7879_READCMD(reg);
-	req->xfer[0].tx_buf = &req->command;
-	req->xfer[0].len = 2;
-
-	req->xfer[1].rx_buf = &req->data;
-	req->xfer[1].len = 2;
-
-	spi_message_add_tail(&req->xfer[0], &req->msg);
-	spi_message_add_tail(&req->xfer[1], &req->msg);
-
-	status = spi_sync(spi, &req->msg);
-	ret = status ? : req->data;
-
-	kfree(req);
-
-	return ret;
-}
-
-static int ad7879_write(struct spi_device *spi, u8 reg, u16 val)
-{
-	struct ser_req *req;
-	int status;
-
-	req = kzalloc(sizeof *req, GFP_KERNEL);
-	if (!req)
-		return -ENOMEM;
-
-	spi_message_init(&req->msg);
-
-	req->command = (u16) AD7879_WRITECMD(reg);
-	req->xfer[0].tx_buf = &req->command;
-	req->xfer[0].len = 2;
-
-	req->data = val;
-	req->xfer[1].tx_buf = &req->data;
-	req->xfer[1].len = 2;
-
-	spi_message_add_tail(&req->xfer[0], &req->msg);
-	spi_message_add_tail(&req->xfer[1], &req->msg);
-
-	status = spi_sync(spi, &req->msg);
-
-	kfree(req);
-
-	return status;
-}
-
-static void ad7879_collect(struct ad7879 *ts)
-{
-	int status = spi_sync(ts->bus, &ts->msg);
-
-	if (status)
-		dev_err(&ts->bus->dev, "spi_sync --> %d\n", status);
-}
-
-static void ad7879_setup_ts_def_msg(struct ad7879 *ts)
-{
-	struct spi_message *m;
-	int i;
-
-	ts->cmd = (u16) AD7879_READCMD(AD7879_REG_XPLUS);
-
-	m = &ts->msg;
-	spi_message_init(m);
-	ts->xfer[0].tx_buf = &ts->cmd;
-	ts->xfer[0].len = 2;
-
-	spi_message_add_tail(&ts->xfer[0], m);
-
-	for (i = 0; i < AD7879_NR_SENSE; i++) {
-		ts->xfer[i + 1].rx_buf = &ts->conversion_data[i];
-		ts->xfer[i + 1].len = 2;
-		spi_message_add_tail(&ts->xfer[i + 1], m);
-	}
-}
-
-static int __devinit ad7879_probe(struct spi_device *spi)
-{
-	struct ad7879 *ts;
-	int error;
-
-	/* don't exceed max specified SPI CLK frequency */
-	if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
-		dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
-		return -EINVAL;
-	}
-
-	ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
-	if (!ts)
-		return -ENOMEM;
-
-	dev_set_drvdata(&spi->dev, ts);
-	ts->bus = spi;
-
-	ad7879_setup_ts_def_msg(ts);
-
-	error = ad7879_construct(spi, ts);
-	if (error) {
-		dev_set_drvdata(&spi->dev, NULL);
-		kfree(ts);
-	}
-
-	return error;
-}
-
-static int __devexit ad7879_remove(struct spi_device *spi)
-{
-	struct ad7879 *ts = dev_get_drvdata(&spi->dev);
-
-	ad7879_destroy(spi, ts);
-	dev_set_drvdata(&spi->dev, NULL);
-	kfree(ts);
-
-	return 0;
-}
-
-static struct spi_driver ad7879_driver = {
-	.driver = {
-		.name	= "ad7879",
-		.bus	= &spi_bus_type,
-		.owner	= THIS_MODULE,
-	},
-	.probe		= ad7879_probe,
-	.remove		= __devexit_p(ad7879_remove),
-	.suspend	= ad7879_suspend,
-	.resume		= ad7879_resume,
-};
-
-static int __init ad7879_init(void)
-{
-	return spi_register_driver(&ad7879_driver);
-}
-module_init(ad7879_init);
-
-static void __exit ad7879_exit(void)
-{
-	spi_unregister_driver(&ad7879_driver);
-}
-module_exit(ad7879_exit);
-
-#elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
-
-/* All registers are word-sized.
- * AD7879 uses a high-byte first convention.
- */
-static int ad7879_read(struct i2c_client *client, u8 reg)
-{
-	return swab16(i2c_smbus_read_word_data(client, reg));
-}
-
-static int ad7879_write(struct i2c_client *client, u8 reg, u16 val)
-{
-	return i2c_smbus_write_word_data(client, reg, swab16(val));
-}
-
-static void ad7879_collect(struct ad7879 *ts)
-{
-	int i;
-
-	for (i = 0; i < AD7879_NR_SENSE; i++)
-		ts->conversion_data[i] = ad7879_read(ts->bus,
-						     AD7879_REG_XPLUS + i);
-}
-
-static int __devinit ad7879_probe(struct i2c_client *client,
-					const struct i2c_device_id *id)
-{
-	struct ad7879 *ts;
-	int error;
-
-	if (!i2c_check_functionality(client->adapter,
-					I2C_FUNC_SMBUS_WORD_DATA)) {
-		dev_err(&client->dev, "SMBUS Word Data not Supported\n");
-		return -EIO;
-	}
-
-	ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
-	if (!ts)
-		return -ENOMEM;
-
-	i2c_set_clientdata(client, ts);
-	ts->bus = client;
-
-	error = ad7879_construct(client, ts);
-	if (error)
-		kfree(ts);
-
-	return error;
-}
-
-static int __devexit ad7879_remove(struct i2c_client *client)
-{
-	struct ad7879 *ts = dev_get_drvdata(&client->dev);
-
-	ad7879_destroy(client, ts);
 	kfree(ts);
-
-	return 0;
 }
-
-static const struct i2c_device_id ad7879_id[] = {
-	{ "ad7879", 0 },
-	{ "ad7889", 0 },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, ad7879_id);
-
-static struct i2c_driver ad7879_driver = {
-	.driver = {
-		.name	= "ad7879",
-		.owner	= THIS_MODULE,
-	},
-	.probe		= ad7879_probe,
-	.remove		= __devexit_p(ad7879_remove),
-	.suspend	= ad7879_suspend,
-	.resume		= ad7879_resume,
-	.id_table	= ad7879_id,
-};
-
-static int __init ad7879_init(void)
-{
-	return i2c_add_driver(&ad7879_driver);
-}
-module_init(ad7879_init);
-
-static void __exit ad7879_exit(void)
-{
-	i2c_del_driver(&ad7879_driver);
-}
-module_exit(ad7879_exit);
-#endif
+EXPORT_SYMBOL(ad7879_remove);
 
 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("spi:ad7879");
diff --git a/drivers/input/touchscreen/ad7879.h b/drivers/input/touchscreen/ad7879.h
new file mode 100644
index 0000000..169f155
--- /dev/null
+++ b/drivers/input/touchscreen/ad7879.h
@@ -0,0 +1,30 @@
+/*
+ * AD7879/AD7889 touchscreen (bus interfaces)
+ *
+ * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef _AD7879_H_
+#define _AD7879_H_
+
+#include <linux/types.h>
+
+struct ad7879;
+struct device;
+
+struct ad7879_bus_ops {
+	u16 bustype;
+	int (*read)(struct device *dev, u8 reg);
+	int (*multi_read)(struct device *dev, u8 first_reg, u8 count, u16 *buf);
+	int (*write)(struct device *dev, u8 reg, u16 val);
+};
+
+void ad7879_disable(struct ad7879 *);
+void ad7879_enable(struct ad7879 *);
+struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned irq,
+			    const struct ad7879_bus_ops *bops);
+void ad7879_remove(struct ad7879 *);
+
+#endif