Input: add support for WM97xx familty touchscreens

Add support for the touchscreen controllers provided by Wolfson
Microelectronics WM97xx series chips in both polled and streaming
modes.

These drivers have been maintained out of tree since 2003. During
that time the driver the primary maintainer was Liam Girdwood and
a number of people have made contributions including Dmitry Baryshkov,
Stanley Cai, Rodolfo Giometti, Russell King, Marc Kleine-Budde,
Ian Molton, Vincent Sanders, Andrew Zabolotny, Graeme Gregory,
Mike Arthur and myself. Apologies to anyone I have omitted.

Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Graeme Gregory <gg@opensource.wolfsonmicro.com>
Signed-off-by: Mike Arthur <mike.arthur@wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

5 files changed, 1127 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 90dcbbcad91c..87bdced169a4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4343,6 +4343,16 @@ L:	linux-wireless@vger.kernel.org
 W:	http://oops.ghostprotocols.net:81/blog
 S:	Maintained
 
+WM97XX TOUCHSCREEN DRIVERS
+P:	Mark Brown
+M:	broonie@opensource.wolfsonmicro.com
+P:	Liam Girdwood
+M:	liam.girdwood@wolfsonmicro.com
+L:	linux-input@vger.kernel.org
+T:	git git://opensource.wolfsonmicro.com/linux-2.6-touch
+W:	http://opensource.wolfsonmicro.com/node/7
+S:	Supported
+
 X.25 NETWORK LAYER
 P:	Henner Eisen
 M:	eis@baty.hanse.de
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 90e8e92dfe47..a95a87cd1d59 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -185,6 +185,20 @@ config TOUCHSCREEN_UCB1400
 	  To compile this driver as a module, choose M here: the
 	  module will be called ucb1400_ts.
 
+config TOUCHSCREEN_WM97XX
+	tristate "Support for WM97xx AC97 touchscreen controllers"
+	depends on AC97_BUS
+	help
+	  Say Y here if you have a Wolfson Microelectronics WM97xx
+	  touchscreen connected to your system. Note that this option
+	  only enables core driver, you will also need to select
+	  support for appropriate chip below.
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called wm97xx-ts.
+
 config TOUCHSCREEN_USB_COMPOSITE
 	tristate "USB Touchscreen Driver"
 	depends on USB_ARCH_HAS_HCD
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 35d4097df35a..b4e7b5dbf649 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -4,6 +4,8 @@
 
 # Each configuration option enables a list of files.
 
+wm97xx-ts-y := wm97xx-core.o
+
 obj-$(CONFIG_TOUCHSCREEN_ADS7846)	+= ads7846.o
 obj-$(CONFIG_TOUCHSCREEN_BITSY)		+= h3600_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_CORGI)		+= corgi_ts.o
@@ -19,3 +21,4 @@ obj-$(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_WM97XX)	+= wm97xx-ts.o
diff --git a/drivers/input/touchscreen/wm97xx-core.c b/drivers/input/touchscreen/wm97xx-core.c
new file mode 100644
index 000000000000..2910999e05a0
--- /dev/null
+++ b/drivers/input/touchscreen/wm97xx-core.c
@@ -0,0 +1,789 @@
+/*
+ * wm97xx-core.c  --  Touch screen driver core for Wolfson WM9705, WM9712
+ *                    and WM9713 AC97 Codecs.
+ *
+ * Copyright 2003, 2004, 2005, 2006, 2007, 2008 Wolfson Microelectronics PLC.
+ * Author: Liam Girdwood
+ *         liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
+ * Parts Copyright : Ian Molton <spyro@f2s.com>
+ *                   Andrew Zabolotny <zap@homelink.ru>
+ *                   Russell King <rmk@arm.linux.org.uk>
+ *
+ *  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.
+ *
+ * Notes:
+ *
+ *  Features:
+ *       - supports WM9705, WM9712, WM9713
+ *       - polling mode
+ *       - continuous mode (arch-dependent)
+ *       - adjustable rpu/dpp settings
+ *       - adjustable pressure current
+ *       - adjustable sample settle delay
+ *       - 4 and 5 wire touchscreens (5 wire is WM9712 only)
+ *       - pen down detection
+ *       - battery monitor
+ *       - sample AUX adcs
+ *       - power management
+ *       - codec GPIO
+ *       - codec event notification
+ * Todo
+ *       - Support for async sampling control for noisy LCDs.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+#include <linux/pm.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <linux/workqueue.h>
+#include <linux/wm97xx.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+#define TS_NAME			"wm97xx"
+#define WM_CORE_VERSION		"1.00"
+#define DEFAULT_PRESSURE	0xb0c0
+
+
+/*
+ * Touchscreen absolute values
+ *
+ * These parameters are used to help the input layer discard out of
+ * range readings and reduce jitter etc.
+ *
+ *   o min, max:- indicate the min and max values your touch screen returns
+ *   o fuzz:- use a higher number to reduce jitter
+ *
+ * The default values correspond to Mainstone II in QVGA mode
+ *
+ * Please read
+ * Documentation/input/input-programming.txt for more details.
+ */
+
+static int abs_x[3] = {350, 3900, 5};
+module_param_array(abs_x, int, NULL, 0);
+MODULE_PARM_DESC(abs_x, "Touchscreen absolute X min, max, fuzz");
+
+static int abs_y[3] = {320, 3750, 40};
+module_param_array(abs_y, int, NULL, 0);
+MODULE_PARM_DESC(abs_y, "Touchscreen absolute Y min, max, fuzz");
+
+static int abs_p[3] = {0, 150, 4};
+module_param_array(abs_p, int, NULL, 0);
+MODULE_PARM_DESC(abs_p, "Touchscreen absolute Pressure min, max, fuzz");
+
+/*
+ * wm97xx IO access, all IO locking done by AC97 layer
+ */
+int wm97xx_reg_read(struct wm97xx *wm, u16 reg)
+{
+	if (wm->ac97)
+		return wm->ac97->bus->ops->read(wm->ac97, reg);
+	else
+		return -1;
+}
+EXPORT_SYMBOL_GPL(wm97xx_reg_read);
+
+void wm97xx_reg_write(struct wm97xx *wm, u16 reg, u16 val)
+{
+	/* cache digitiser registers */
+	if (reg >= AC97_WM9713_DIG1 && reg <= AC97_WM9713_DIG3)
+		wm->dig[(reg - AC97_WM9713_DIG1) >> 1] = val;
+
+	/* cache gpio regs */
+	if (reg >= AC97_GPIO_CFG && reg <= AC97_MISC_AFE)
+		wm->gpio[(reg - AC97_GPIO_CFG) >> 1] = val;
+
+	/* wm9713 irq reg */
+	if (reg == 0x5a)
+		wm->misc = val;
+
+	if (wm->ac97)
+		wm->ac97->bus->ops->write(wm->ac97, reg, val);
+}
+EXPORT_SYMBOL_GPL(wm97xx_reg_write);
+
+/**
+ * wm97xx_read_aux_adc - Read the aux adc.
+ * @wm: wm97xx device.
+ * @adcsel: codec ADC to be read
+ *
+ * Reads the selected AUX ADC.
+ */
+
+int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel)
+{
+	int power_adc = 0, auxval;
+	u16 power = 0;
+
+	/* get codec */
+	mutex_lock(&wm->codec_mutex);
+
+	/* When the touchscreen is not in use, we may have to power up
+	 * the AUX ADC before we can use sample the AUX inputs->
+	 */
+	if (wm->id == WM9713_ID2 &&
+	    (power = wm97xx_reg_read(wm, AC97_EXTENDED_MID)) & 0x8000) {
+		power_adc = 1;
+		wm97xx_reg_write(wm, AC97_EXTENDED_MID, power & 0x7fff);
+	}
+
+	/* Prepare the codec for AUX reading */
+	wm->codec->aux_prepare(wm);
+
+	/* Turn polling mode on to read AUX ADC */
+	wm->pen_probably_down = 1;
+	wm->codec->poll_sample(wm, adcsel, &auxval);
+
+	if (power_adc)
+		wm97xx_reg_write(wm, AC97_EXTENDED_MID, power | 0x8000);
+
+	wm->codec->dig_restore(wm);
+
+	wm->pen_probably_down = 0;
+
+	mutex_unlock(&wm->codec_mutex);
+	return auxval & 0xfff;
+}
+EXPORT_SYMBOL_GPL(wm97xx_read_aux_adc);
+
+/**
+ * wm97xx_get_gpio - Get the status of a codec GPIO.
+ * @wm: wm97xx device.
+ * @gpio: gpio
+ *
+ * Get the status of a codec GPIO pin
+ */
+
+enum wm97xx_gpio_status wm97xx_get_gpio(struct wm97xx *wm, u32 gpio)
+{
+	u16 status;
+	enum wm97xx_gpio_status ret;
+
+	mutex_lock(&wm->codec_mutex);
+	status = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
+
+	if (status & gpio)
+		ret = WM97XX_GPIO_HIGH;
+	else
+		ret = WM97XX_GPIO_LOW;
+
+	mutex_unlock(&wm->codec_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(wm97xx_get_gpio);
+
+/**
+ * wm97xx_set_gpio - Set the status of a codec GPIO.
+ * @wm: wm97xx device.
+ * @gpio: gpio
+ *
+ *
+ * Set the status of a codec GPIO pin
+ */
+
+void wm97xx_set_gpio(struct wm97xx *wm, u32 gpio,
+				enum wm97xx_gpio_status status)
+{
+	u16 reg;
+
+	mutex_lock(&wm->codec_mutex);
+	reg = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
+
+	if (status & WM97XX_GPIO_HIGH)
+		reg |= gpio;
+	else
+		reg &= ~gpio;
+
+	if (wm->id == WM9712_ID2)
+		wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg << 1);
+	else
+		wm97xx_reg_write(wm, AC97_GPIO_STATUS, reg);
+	mutex_unlock(&wm->codec_mutex);
+}
+EXPORT_SYMBOL_GPL(wm97xx_set_gpio);
+
+/*
+ * Codec GPIO pin configuration, this sets pin direction, polarity,
+ * stickyness and wake up.
+ */
+void wm97xx_config_gpio(struct wm97xx *wm, u32 gpio, enum wm97xx_gpio_dir dir,
+		   enum wm97xx_gpio_pol pol, enum wm97xx_gpio_sticky sticky,
+		   enum wm97xx_gpio_wake wake)
+{
+	u16 reg;
+
+	mutex_lock(&wm->codec_mutex);
+	reg = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
+
+	if (pol == WM97XX_GPIO_POL_HIGH)
+		reg |= gpio;
+	else
+		reg &= ~gpio;
+
+	wm97xx_reg_write(wm, AC97_GPIO_POLARITY, reg);
+	reg = wm97xx_reg_read(wm, AC97_GPIO_STICKY);
+
+	if (sticky == WM97XX_GPIO_STICKY)
+		reg |= gpio;
+	else
+		reg &= ~gpio;
+
+	wm97xx_reg_write(wm, AC97_GPIO_STICKY, reg);
+	reg = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP);
+
+	if (wake == WM97XX_GPIO_WAKE)
+		reg |= gpio;
+	else
+		reg &= ~gpio;
+
+	wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, reg);
+	reg = wm97xx_reg_read(wm, AC97_GPIO_CFG);
+
+	if (dir == WM97XX_GPIO_IN)
+		reg |= gpio;
+	else
+		reg &= ~gpio;
+
+	wm97xx_reg_write(wm, AC97_GPIO_CFG, reg);
+	mutex_unlock(&wm->codec_mutex);
+}
+EXPORT_SYMBOL_GPL(wm97xx_config_gpio);
+
+/*
+ * Handle a pen down interrupt.
+ */
+static void wm97xx_pen_irq_worker(struct work_struct *work)
+{
+	struct wm97xx *wm = container_of(work, struct wm97xx, pen_event_work);
+	int pen_was_down = wm->pen_is_down;
+
+	/* do we need to enable the touch panel reader */
+	if (wm->id == WM9705_ID2) {
+		if (wm97xx_reg_read(wm, AC97_WM97XX_DIGITISER_RD) &
+					WM97XX_PEN_DOWN)
+			wm->pen_is_down = 1;
+		else
+			wm->pen_is_down = 0;
+	} else {
+		u16 status, pol;
+		mutex_lock(&wm->codec_mutex);
+		status = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
+		pol = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
+
+		if (WM97XX_GPIO_13 & pol & status) {
+			wm->pen_is_down = 1;
+			wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol &
+						~WM97XX_GPIO_13);
+		} else {
+			wm->pen_is_down = 0;
+			wm97xx_reg_write(wm, AC97_GPIO_POLARITY, pol |
+					 WM97XX_GPIO_13);
+		}
+
+		if (wm->id == WM9712_ID2)
+			wm97xx_reg_write(wm, AC97_GPIO_STATUS, (status &
+						~WM97XX_GPIO_13) << 1);
+		else
+			wm97xx_reg_write(wm, AC97_GPIO_STATUS, status &
+						~WM97XX_GPIO_13);
+		mutex_unlock(&wm->codec_mutex);
+	}
+
+	/* If the system is not using continuous mode or it provides a
+	 * pen down operation then we need to schedule polls while the
+	 * pen is down.  Otherwise the machine driver is responsible
+	 * for scheduling reads.
+	 */
+	if (!wm->mach_ops->acc_enabled || wm->mach_ops->acc_pen_down) {
+		if (wm->pen_is_down && !pen_was_down) {
+			/* Data is not availiable immediately on pen down */
+			queue_delayed_work(wm->ts_workq, &wm->ts_reader, 1);
+		}
+
+		/* Let ts_reader report the pen up for debounce. */
+		if (!wm->pen_is_down && pen_was_down)
+			wm->pen_is_down = 1;
+	}
+
+	if (!wm->pen_is_down && wm->mach_ops->acc_enabled)
+		wm->mach_ops->acc_pen_up(wm);
+
+	wm->mach_ops->irq_enable(wm, 1);
+}
+
+/*
+ * Codec PENDOWN irq handler
+ *
+ * We have to disable the codec interrupt in the handler because it
+ * can take upto 1ms to clear the interrupt source. We schedule a task
+ * in a work queue to do the actual interaction with the chip (it
+ * doesn't matter if we end up reenqueing it before it is executed
+ * since we don't touch the chip until it has run).  The interrupt is
+ * then enabled again in the slow handler when the source has been
+ * cleared.
+ */
+static irqreturn_t wm97xx_pen_interrupt(int irq, void *dev_id)
+{
+	struct wm97xx *wm = dev_id;
+
+	wm->mach_ops->irq_enable(wm, 0);
+	queue_work(wm->ts_workq, &wm->pen_event_work);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * initialise pen IRQ handler and workqueue
+ */
+static int wm97xx_init_pen_irq(struct wm97xx *wm)
+{
+	u16 reg;
+
+	/* If an interrupt is supplied an IRQ enable operation must also be
+	 * provided. */
+	BUG_ON(!wm->mach_ops->irq_enable);
+
+	if (request_irq(wm->pen_irq, wm97xx_pen_interrupt, IRQF_SHARED,
+			"wm97xx-pen", wm)) {
+		dev_err(wm->dev,
+			"Failed to register pen down interrupt, polling");
+		wm->pen_irq = 0;
+		return -EINVAL;
+	}
+
+	/* Configure GPIO as interrupt source on WM971x */
+	if (wm->id != WM9705_ID2) {
+		BUG_ON(!wm->mach_ops->irq_gpio);
+		reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
+		wm97xx_reg_write(wm, AC97_MISC_AFE,
+				reg & ~(wm->mach_ops->irq_gpio));
+		reg = wm97xx_reg_read(wm, 0x5a);
+		wm97xx_reg_write(wm, 0x5a, reg & ~0x0001);
+	}
+
+	return 0;
+}
+
+static int wm97xx_read_samples(struct wm97xx *wm)
+{
+	struct wm97xx_data data;
+	int rc;
+
+	mutex_lock(&wm->codec_mutex);
+
+	if (wm->mach_ops && wm->mach_ops->acc_enabled)
+		rc = wm->mach_ops->acc_pen_down(wm);
+	else
+		rc = wm->codec->poll_touch(wm, &data);
+
+	if (rc & RC_PENUP) {
+		if (wm->pen_is_down) {
+			wm->pen_is_down = 0;
+			dev_dbg(wm->dev, "pen up\n");
+			input_report_abs(wm->input_dev, ABS_PRESSURE, 0);
+			input_sync(wm->input_dev);
+		} else if (!(rc & RC_AGAIN)) {
+			/* We need high frequency updates only while
+			* pen is down, the user never will be able to
+			* touch screen faster than a few times per
+			* second... On the other hand, when the user
+			* is actively working with the touchscreen we
+			* don't want to lose the quick response. So we
+			* will slowly increase sleep time after the
+			* pen is up and quicky restore it to ~one task
+			* switch when pen is down again.
+			*/
+			if (wm->ts_reader_interval < HZ / 10)
+				wm->ts_reader_interval++;
+		}
+
+	} else if (rc & RC_VALID) {
+		dev_dbg(wm->dev,
+			"pen down: x=%x:%d, y=%x:%d, pressure=%x:%d\n",
+			data.x >> 12, data.x & 0xfff, data.y >> 12,
+			data.y & 0xfff, data.p >> 12, data.p & 0xfff);
+		input_report_abs(wm->input_dev, ABS_X, data.x & 0xfff);
+		input_report_abs(wm->input_dev, ABS_Y, data.y & 0xfff);
+		input_report_abs(wm->input_dev, ABS_PRESSURE, data.p & 0xfff);
+		input_sync(wm->input_dev);
+		wm->pen_is_down = 1;
+		wm->ts_reader_interval = wm->ts_reader_min_interval;
+	} else if (rc & RC_PENDOWN) {
+		dev_dbg(wm->dev, "pen down\n");
+		wm->pen_is_down = 1;
+		wm->ts_reader_interval = wm->ts_reader_min_interval;
+	}
+
+	mutex_unlock(&wm->codec_mutex);
+	return rc;
+}
+
+/*
+* The touchscreen sample reader.
+*/
+static void wm97xx_ts_reader(struct work_struct *work)
+{
+	int rc;
+	struct wm97xx *wm = container_of(work, struct wm97xx, ts_reader.work);
+
+	BUG_ON(!wm->codec);
+
+	do {
+		rc = wm97xx_read_samples(wm);
+	} while (rc & RC_AGAIN);
+
+	if (wm->pen_is_down || !wm->pen_irq)
+		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
+				   wm->ts_reader_interval);
+}
+
+/**
+ * wm97xx_ts_input_open - Open the touch screen input device.
+ * @idev:	Input device to be opened.
+ *
+ * Called by the input sub system to open a wm97xx touchscreen device.
+ * Starts the touchscreen thread and touch digitiser.
+ */
+static int wm97xx_ts_input_open(struct input_dev *idev)
+{
+	struct wm97xx *wm = input_get_drvdata(idev);
+
+	wm->ts_workq = create_singlethread_workqueue("kwm97xx");
+	if (wm->ts_workq == NULL) {
+		dev_err(wm->dev,
+			"Failed to create workqueue\n");
+		return -EINVAL;
+	}
+
+	/* start digitiser */
+	if (wm->mach_ops && wm->mach_ops->acc_enabled)
+		wm->codec->acc_enable(wm, 1);
+	wm->codec->dig_enable(wm, 1);
+
+	INIT_DELAYED_WORK(&wm->ts_reader, wm97xx_ts_reader);
+	INIT_WORK(&wm->pen_event_work, wm97xx_pen_irq_worker);
+
+	wm->ts_reader_min_interval = HZ >= 100 ? HZ / 100 : 1;
+	if (wm->ts_reader_min_interval < 1)
+		wm->ts_reader_min_interval = 1;
+	wm->ts_reader_interval = wm->ts_reader_min_interval;
+
+	wm->pen_is_down = 0;
+	if (wm->pen_irq)
+		wm97xx_init_pen_irq(wm);
+	else
+		dev_err(wm->dev, "No IRQ specified\n");
+
+	/* If we either don't have an interrupt for pen down events or
+	 * failed to acquire it then we need to poll.
+	 */
+	if (wm->pen_irq == 0)
+		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
+				   wm->ts_reader_interval);
+
+	return 0;
+}
+
+/**
+ * wm97xx_ts_input_close - Close the touch screen input device.
+ * @idev:	Input device to be closed.
+ *
+ * Called by the input sub system to close a wm97xx touchscreen
+ * device.  Kills the touchscreen thread and stops the touch
+ * digitiser.
+ */
+
+static void wm97xx_ts_input_close(struct input_dev *idev)
+{
+	struct wm97xx *wm = input_get_drvdata(idev);
+	u16 reg;
+
+	if (wm->pen_irq) {
+		/* Return the interrupt to GPIO usage (disabling it) */
+		if (wm->id != WM9705_ID2) {
+			BUG_ON(!wm->mach_ops->irq_gpio);
+			reg = wm97xx_reg_read(wm, AC97_MISC_AFE);
+			wm97xx_reg_write(wm, AC97_MISC_AFE,
+					 reg | wm->mach_ops->irq_gpio);
+		}
+
+		free_irq(wm->pen_irq, wm);
+	}
+
+	wm->pen_is_down = 0;
+
+	/* Balance out interrupt disables/enables */
+	if (cancel_work_sync(&wm->pen_event_work))
+		wm->mach_ops->irq_enable(wm, 1);
+
+	/* ts_reader rearms itself so we need to explicitly stop it
+	 * before we destroy the workqueue.
+	 */
+	cancel_delayed_work_sync(&wm->ts_reader);
+
+	destroy_workqueue(wm->ts_workq);
+
+	/* stop digitiser */
+	wm->codec->dig_enable(wm, 0);
+	if (wm->mach_ops && wm->mach_ops->acc_enabled)
+		wm->codec->acc_enable(wm, 0);
+}
+
+static int wm97xx_probe(struct device *dev)
+{
+	struct wm97xx *wm;
+	int ret = 0, id = 0;
+
+	wm = kzalloc(sizeof(struct wm97xx), GFP_KERNEL);
+	if (!wm)
+		return -ENOMEM;
+	mutex_init(&wm->codec_mutex);
+
+	wm->dev = dev;
+	dev->driver_data = wm;
+	wm->ac97 = to_ac97_t(dev);
+
+	/* check that we have a supported codec */
+	id = wm97xx_reg_read(wm, AC97_VENDOR_ID1);
+	if (id != WM97XX_ID1) {
+		dev_err(dev, "Device with vendor %04x is not a wm97xx\n", id);
+		ret = -ENODEV;
+		goto alloc_err;
+	}
+
+	wm->id = wm97xx_reg_read(wm, AC97_VENDOR_ID2);
+
+	dev_info(wm->dev, "detected a wm97%02x codec\n", wm->id & 0xff);
+
+	switch (wm->id & 0xff) {
+#ifdef CONFIG_TOUCHSCREEN_WM9705
+	case 0x05:
+		wm->codec = &wm9705_codec;
+		break;
+#endif
+#ifdef CONFIG_TOUCHSCREEN_WM9712
+	case 0x12:
+		wm->codec = &wm9712_codec;
+		break;
+#endif
+#ifdef CONFIG_TOUCHSCREEN_WM9713
+	case 0x13:
+		wm->codec = &wm9713_codec;
+		break;
+#endif
+	default:
+		dev_err(wm->dev, "Support for wm97%02x not compiled in.\n",
+			wm->id & 0xff);
+		ret = -ENODEV;
+		goto alloc_err;
+	}
+
+	wm->input_dev = input_allocate_device();
+	if (wm->input_dev == NULL) {
+		ret = -ENOMEM;
+		goto alloc_err;
+	}
+
+	/* set up touch configuration */
+	wm->input_dev->name = "wm97xx touchscreen";
+	wm->input_dev->open = wm97xx_ts_input_open;
+	wm->input_dev->close = wm97xx_ts_input_close;
+	set_bit(EV_ABS, wm->input_dev->evbit);
+	set_bit(ABS_X, wm->input_dev->absbit);
+	set_bit(ABS_Y, wm->input_dev->absbit);
+	set_bit(ABS_PRESSURE, wm->input_dev->absbit);
+	input_set_abs_params(wm->input_dev, ABS_X, abs_x[0], abs_x[1],
+			     abs_x[2], 0);
+	input_set_abs_params(wm->input_dev, ABS_Y, abs_y[0], abs_y[1],
+			     abs_y[2], 0);
+	input_set_abs_params(wm->input_dev, ABS_PRESSURE, abs_p[0], abs_p[1],
+			     abs_p[2], 0);
+	input_set_drvdata(wm->input_dev, wm);
+	wm->input_dev->dev.parent = dev;
+	ret = input_register_device(wm->input_dev);
+	if (ret < 0)
+		goto dev_alloc_err;
+
+	/* set up physical characteristics */
+	wm->codec->phy_init(wm);
+
+	/* load gpio cache */
+	wm->gpio[0] = wm97xx_reg_read(wm, AC97_GPIO_CFG);
+	wm->gpio[1] = wm97xx_reg_read(wm, AC97_GPIO_POLARITY);
+	wm->gpio[2] = wm97xx_reg_read(wm, AC97_GPIO_STICKY);
+	wm->gpio[3] = wm97xx_reg_read(wm, AC97_GPIO_WAKEUP);
+	wm->gpio[4] = wm97xx_reg_read(wm, AC97_GPIO_STATUS);
+	wm->gpio[5] = wm97xx_reg_read(wm, AC97_MISC_AFE);
+
+	/* register our battery device */
+	wm->battery_dev = platform_device_alloc("wm97xx-battery", -1);
+	if (!wm->battery_dev) {
+		ret = -ENOMEM;
+		goto batt_err;
+	}
+	platform_set_drvdata(wm->battery_dev, wm);
+	wm->battery_dev->dev.parent = dev;
+	ret = platform_device_add(wm->battery_dev);
+	if (ret < 0)
+		goto batt_reg_err;
+
+	/* register our extended touch device (for machine specific
+	 * extensions) */
+	wm->touch_dev = platform_device_alloc("wm97xx-touch", -1);
+	if (!wm->touch_dev) {
+		ret = -ENOMEM;
+		goto touch_err;
+	}
+	platform_set_drvdata(wm->touch_dev, wm);
+	wm->touch_dev->dev.parent = dev;
+	ret = platform_device_add(wm->touch_dev);
+	if (ret < 0)
+		goto touch_reg_err;
+
+	return ret;
+
+ touch_reg_err:
+	platform_device_put(wm->touch_dev);
+ touch_err:
+	platform_device_unregister(wm->battery_dev);
+	wm->battery_dev = NULL;
+ batt_reg_err:
+	platform_device_put(wm->battery_dev);
+ batt_err:
+	input_unregister_device(wm->input_dev);
+	wm->input_dev = NULL;
+ dev_alloc_err:
+	input_free_device(wm->input_dev);
+ alloc_err:
+	kfree(wm);
+
+	return ret;
+}
+
+static int wm97xx_remove(struct device *dev)
+{
+	struct wm97xx *wm = dev_get_drvdata(dev);
+
+	platform_device_unregister(wm->battery_dev);
+	platform_device_unregister(wm->touch_dev);
+	input_unregister_device(wm->input_dev);
+	kfree(wm);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int wm97xx_suspend(struct device *dev, pm_message_t state)
+{
+	struct wm97xx *wm = dev_get_drvdata(dev);
+
+	if (wm->input_dev->users)
+		cancel_delayed_work_sync(&wm->ts_reader);
+
+	return 0;
+}
+
+static int wm97xx_resume(struct device *dev)
+{
+	struct wm97xx *wm = dev_get_drvdata(dev);
+
+	/* restore digitiser and gpios */
+	if (wm->id == WM9713_ID2) {
+		wm97xx_reg_write(wm, AC97_WM9713_DIG1, wm->dig[0]);
+		wm97xx_reg_write(wm, 0x5a, wm->misc);
+		if (wm->input_dev->users) {
+			u16 reg;
+			reg = wm97xx_reg_read(wm, AC97_EXTENDED_MID) & 0x7fff;
+			wm97xx_reg_write(wm, AC97_EXTENDED_MID, reg);
+		}
+	}
+
+	wm97xx_reg_write(wm, AC97_WM9713_DIG2, wm->dig[1]);
+	wm97xx_reg_write(wm, AC97_WM9713_DIG3, wm->dig[2]);
+
+	wm97xx_reg_write(wm, AC97_GPIO_CFG, wm->gpio[0]);
+	wm97xx_reg_write(wm, AC97_GPIO_POLARITY, wm->gpio[1]);
+	wm97xx_reg_write(wm, AC97_GPIO_STICKY, wm->gpio[2]);
+	wm97xx_reg_write(wm, AC97_GPIO_WAKEUP, wm->gpio[3]);
+	wm97xx_reg_write(wm, AC97_GPIO_STATUS, wm->gpio[4]);
+	wm97xx_reg_write(wm, AC97_MISC_AFE, wm->gpio[5]);
+
+	if (wm->input_dev->users && !wm->pen_irq) {
+		wm->ts_reader_interval = wm->ts_reader_min_interval;
+		queue_delayed_work(wm->ts_workq, &wm->ts_reader,
+				   wm->ts_reader_interval);
+	}
+
+	return 0;
+}
+
+#else
+#define wm97xx_suspend		NULL
+#define wm97xx_resume		NULL
+#endif
+
+/*
+ * Machine specific operations
+ */
+int wm97xx_register_mach_ops(struct wm97xx *wm,
+			     struct wm97xx_mach_ops *mach_ops)
+{
+	mutex_lock(&wm->codec_mutex);
+	if (wm->mach_ops) {
+		mutex_unlock(&wm->codec_mutex);
+		return -EINVAL;
+	}
+	wm->mach_ops = mach_ops;
+	mutex_unlock(&wm->codec_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(wm97xx_register_mach_ops);
+
+void wm97xx_unregister_mach_ops(struct wm97xx *wm)
+{
+	mutex_lock(&wm->codec_mutex);
+	wm->mach_ops = NULL;
+	mutex_unlock(&wm->codec_mutex);
+}
+EXPORT_SYMBOL_GPL(wm97xx_unregister_mach_ops);
+
+static struct device_driver wm97xx_driver = {
+	.name =		"ac97",
+	.bus =		&ac97_bus_type,
+	.owner =	THIS_MODULE,
+	.probe =	wm97xx_probe,
+	.remove =	wm97xx_remove,
+	.suspend =	wm97xx_suspend,
+	.resume =	wm97xx_resume,
+};
+
+static int __init wm97xx_init(void)
+{
+	return driver_register(&wm97xx_driver);
+}
+
+static void __exit wm97xx_exit(void)
+{
+	driver_unregister(&wm97xx_driver);
+}
+
+module_init(wm97xx_init);
+module_exit(wm97xx_exit);
+
+/* Module information */
+MODULE_AUTHOR("Liam Girdwood <liam.girdwood@wolfsonmicro.com>");
+MODULE_DESCRIPTION("WM97xx Core - Touch Screen / AUX ADC / GPIO Driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/wm97xx.h b/include/linux/wm97xx.h
new file mode 100644
index 000000000000..ed01c7df54a3
--- /dev/null
+++ b/include/linux/wm97xx.h
@@ -0,0 +1,311 @@
+
+/*
+ * Register bits and API for Wolfson WM97xx series of codecs
+ */
+
+#ifndef _LINUX_WM97XX_H
+#define _LINUX_WM97XX_H
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/ac97_codec.h>
+#include <sound/initval.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/input.h>	/* Input device layer */
+#include <linux/platform_device.h>
+
+/*
+ * WM97xx AC97 Touchscreen registers
+ */
+#define AC97_WM97XX_DIGITISER1		0x76
+#define AC97_WM97XX_DIGITISER2		0x78
+#define AC97_WM97XX_DIGITISER_RD 	0x7a
+#define AC97_WM9713_DIG1		0x74
+#define AC97_WM9713_DIG2		AC97_WM97XX_DIGITISER1
+#define AC97_WM9713_DIG3		AC97_WM97XX_DIGITISER2
+
+/*
+ * WM97xx register bits
+ */
+#define WM97XX_POLL		0x8000	/* initiate a polling measurement */
+#define WM97XX_ADCSEL_X		0x1000	/* x coord measurement */
+#define WM97XX_ADCSEL_Y		0x2000	/* y coord measurement */
+#define WM97XX_ADCSEL_PRES	0x3000	/* pressure measurement */
+#define WM97XX_ADCSEL_MASK	0x7000
+#define WM97XX_COO		0x0800	/* enable coordinate mode */
+#define WM97XX_CTC		0x0400	/* enable continuous mode */
+#define WM97XX_CM_RATE_93	0x0000	/* 93.75Hz continuous rate */
+#define WM97XX_CM_RATE_187	0x0100	/* 187.5Hz continuous rate */
+#define WM97XX_CM_RATE_375	0x0200	/* 375Hz continuous rate */
+#define WM97XX_CM_RATE_750	0x0300	/* 750Hz continuous rate */
+#define WM97XX_CM_RATE_8K	0x00f0	/* 8kHz continuous rate */
+#define WM97XX_CM_RATE_12K	0x01f0	/* 12kHz continuous rate */
+#define WM97XX_CM_RATE_24K	0x02f0	/* 24kHz continuous rate */
+#define WM97XX_CM_RATE_48K	0x03f0	/* 48kHz continuous rate */
+#define WM97XX_CM_RATE_MASK	0x03f0
+#define WM97XX_RATE(i)		(((i & 3) << 8) | ((i & 4) ? 0xf0 : 0))
+#define WM97XX_DELAY(i)		((i << 4) & 0x00f0)	/* sample delay times */
+#define WM97XX_DELAY_MASK	0x00f0
+#define WM97XX_SLEN		0x0008	/* slot read back enable */
+#define WM97XX_SLT(i)		((i - 5) & 0x7)	/* panel slot (5-11) */
+#define WM97XX_SLT_MASK		0x0007
+#define WM97XX_PRP_DETW		0x4000	/* detect on, digitise off, wake */
+#define WM97XX_PRP_DET		0x8000	/* detect on, digitise off, no wake */
+#define WM97XX_PRP_DET_DIG	0xc000	/* setect on, digitise on */
+#define WM97XX_RPR		0x2000	/* wake up on pen down */
+#define WM97XX_PEN_DOWN		0x8000	/* pen is down */
+#define WM97XX_ADCSRC_MASK	0x7000	/* ADC source mask */
+
+#define WM97XX_AUX_ID1		0x8001
+#define WM97XX_AUX_ID2		0x8002
+#define WM97XX_AUX_ID3		0x8003
+#define WM97XX_AUX_ID4		0x8004
+
+
+/* WM9712 Bits */
+#define WM9712_45W		0x1000	/* set for 5-wire touchscreen */
+#define WM9712_PDEN		0x0800	/* measure only when pen down */
+#define WM9712_WAIT		0x0200	/* wait until adc is read before next sample */
+#define WM9712_PIL		0x0100	/* current used for pressure measurement. set 400uA else 200uA */
+#define WM9712_MASK_HI		0x0040	/* hi on mask pin (47) stops conversions */
+#define WM9712_MASK_EDGE	0x0080	/* rising/falling edge on pin delays sample */
+#define	WM9712_MASK_SYNC	0x00c0	/* rising/falling edge on mask initiates sample */
+#define WM9712_RPU(i)		(i&0x3f)	/* internal pull up on pen detect (64k / rpu) */
+#define WM9712_PD(i)		(0x1 << i)	/* power management */
+
+/* WM9712 Registers */
+#define AC97_WM9712_POWER	0x24
+#define AC97_WM9712_REV		0x58
+
+/* WM9705 Bits */
+#define WM9705_PDEN		0x1000	/* measure only when pen is down */
+#define WM9705_PINV		0x0800	/* inverts sense of pen down output */
+#define WM9705_BSEN		0x0400	/* BUSY flag enable, pin47 is 1 when busy */
+#define WM9705_BINV		0x0200	/* invert BUSY (pin47) output */
+#define WM9705_WAIT		0x0100	/* wait until adc is read before next sample */
+#define WM9705_PIL		0x0080	/* current used for pressure measurement. set 400uA else 200uA */
+#define WM9705_PHIZ		0x0040	/* set PHONE and PCBEEP inputs to high impedance */
+#define WM9705_MASK_HI		0x0010	/* hi on mask stops conversions */
+#define WM9705_MASK_EDGE	0x0020	/* rising/falling edge on pin delays sample */
+#define	WM9705_MASK_SYNC	0x0030	/* rising/falling edge on mask initiates sample */
+#define WM9705_PDD(i)		(i & 0x000f)	/* pen detect comparator threshold */
+
+
+/* WM9713 Bits */
+#define WM9713_PDPOL		0x0400	/* Pen down polarity */
+#define WM9713_POLL		0x0200	/* initiate a polling measurement */
+#define WM9713_CTC		0x0100	/* enable continuous mode */
+#define WM9713_ADCSEL_X		0x0002	/* X measurement */
+#define WM9713_ADCSEL_Y		0x0004	/* Y measurement */
+#define WM9713_ADCSEL_PRES	0x0008	/* Pressure measurement */
+#define WM9713_COO		0x0001	/* enable coordinate mode */
+#define WM9713_PDEN		0x0800	/* measure only when pen down */
+#define WM9713_ADCSEL_MASK	0x00fe	/* ADC selection mask */
+#define WM9713_WAIT		0x0200	/* coordinate wait */
+
+/* AUX ADC ID's */
+#define TS_COMP1		0x0
+#define TS_COMP2		0x1
+#define TS_BMON			0x2
+#define TS_WIPER		0x3
+
+/* ID numbers */
+#define WM97XX_ID1		0x574d
+#define WM9712_ID2		0x4c12
+#define WM9705_ID2		0x4c05
+#define WM9713_ID2		0x4c13
+
+/* Codec GPIO's */
+#define WM97XX_MAX_GPIO		16
+#define WM97XX_GPIO_1		(1 << 1)
+#define WM97XX_GPIO_2		(1 << 2)
+#define WM97XX_GPIO_3		(1 << 3)
+#define WM97XX_GPIO_4		(1 << 4)
+#define WM97XX_GPIO_5		(1 << 5)
+#define WM97XX_GPIO_6		(1 << 6)
+#define WM97XX_GPIO_7		(1 << 7)
+#define WM97XX_GPIO_8		(1 << 8)
+#define WM97XX_GPIO_9		(1 << 9)
+#define WM97XX_GPIO_10		(1 << 10)
+#define WM97XX_GPIO_11		(1 << 11)
+#define WM97XX_GPIO_12		(1 << 12)
+#define WM97XX_GPIO_13		(1 << 13)
+#define WM97XX_GPIO_14		(1 << 14)
+#define WM97XX_GPIO_15		(1 << 15)
+
+
+#define AC97_LINK_FRAME		21	/* time in uS for AC97 link frame */
+
+
+/*---------------- Return codes from sample reading functions ---------------*/
+
+/* More data is available; call the sample gathering function again */
+#define RC_AGAIN			0x00000001
+/* The returned sample is valid */
+#define RC_VALID			0x00000002
+/* The pen is up (the first RC_VALID without RC_PENUP means pen is down) */
+#define RC_PENUP			0x00000004
+/* The pen is down (RC_VALID implies RC_PENDOWN, but sometimes it is helpful
+   to tell the handler that the pen is down but we don't know yet his coords,
+   so the handler should not sleep or wait for pendown irq) */
+#define RC_PENDOWN			0x00000008
+
+/*
+ * The wm97xx driver provides a private API for writing platform-specific
+ * drivers.
+ */
+
+/* The structure used to return arch specific sampled data into */
+struct wm97xx_data {
+    int x;
+    int y;
+    int p;
+};
+
+/*
+ * Codec GPIO status
+ */
+enum wm97xx_gpio_status {
+    WM97XX_GPIO_HIGH,
+    WM97XX_GPIO_LOW
+};
+
+/*
+ * Codec GPIO direction
+ */
+enum wm97xx_gpio_dir {
+    WM97XX_GPIO_IN,
+    WM97XX_GPIO_OUT
+};
+
+/*
+ * Codec GPIO polarity
+ */
+enum wm97xx_gpio_pol {
+    WM97XX_GPIO_POL_HIGH,
+    WM97XX_GPIO_POL_LOW
+};
+
+/*
+ * Codec GPIO sticky
+ */
+enum wm97xx_gpio_sticky {
+    WM97XX_GPIO_STICKY,
+    WM97XX_GPIO_NOTSTICKY
+};
+
+/*
+ * Codec GPIO wake
+ */
+enum wm97xx_gpio_wake {
+    WM97XX_GPIO_WAKE,
+    WM97XX_GPIO_NOWAKE
+};
+
+/*
+ * Digitiser ioctl commands
+ */
+#define WM97XX_DIG_START	0x1
+#define WM97XX_DIG_STOP		0x2
+#define WM97XX_PHY_INIT		0x3
+#define WM97XX_AUX_PREPARE	0x4
+#define WM97XX_DIG_RESTORE	0x5
+
+struct wm97xx;
+
+extern struct wm97xx_codec_drv wm9705_codec;
+extern struct wm97xx_codec_drv wm9712_codec;
+extern struct wm97xx_codec_drv wm9713_codec;
+
+/*
+ * Codec driver interface - allows mapping to WM9705/12/13 and newer codecs
+ */
+struct wm97xx_codec_drv {
+	u16 id;
+	char *name;
+
+	/* read 1 sample */
+	int (*poll_sample) (struct wm97xx *, int adcsel, int *sample);
+
+	/* read X,Y,[P] in poll */
+	int (*poll_touch) (struct wm97xx *, struct wm97xx_data *);
+
+	int (*acc_enable) (struct wm97xx *, int enable);
+	void (*phy_init) (struct wm97xx *);
+	void (*dig_enable) (struct wm97xx *, int enable);
+	void (*dig_restore) (struct wm97xx *);
+	void (*aux_prepare) (struct wm97xx *);
+};
+
+
+/* Machine specific and accelerated touch operations */
+struct wm97xx_mach_ops {
+
+	/* accelerated touch readback - coords are transmited on AC97 link */
+	int acc_enabled;
+	void (*acc_pen_up) (struct wm97xx *);
+	int (*acc_pen_down) (struct wm97xx *);
+	int (*acc_startup) (struct wm97xx *);
+	void (*acc_shutdown) (struct wm97xx *);
+
+	/* interrupt mask control - required for accelerated operation */
+	void (*irq_enable) (struct wm97xx *, int enable);
+
+	/* GPIO pin used for accelerated operation */
+	int irq_gpio;
+
+	/* pre and post sample - can be used to minimise any analog noise */
+	void (*pre_sample) (int);  /* function to run before sampling */
+	void (*post_sample) (int);  /* function to run after sampling */
+};
+
+struct wm97xx {
+	u16 dig[3], id, gpio[6], misc;	/* Cached codec registers */
+	u16 dig_save[3];		/* saved during aux reading */
+	struct wm97xx_codec_drv *codec;	/* attached codec driver*/
+	struct input_dev *input_dev;	/* touchscreen input device */
+	struct snd_ac97 *ac97;		/* ALSA codec access */
+	struct device *dev;		/* ALSA device */
+	struct platform_device *battery_dev;
+	struct platform_device *touch_dev;
+	struct wm97xx_mach_ops *mach_ops;
+	struct mutex codec_mutex;
+	struct delayed_work ts_reader;  /* Used to poll touchscreen */
+	unsigned long ts_reader_interval; /* Current interval for timer */
+	unsigned long ts_reader_min_interval; /* Minimum interval */
+	unsigned int pen_irq;		/* Pen IRQ number in use */
+	struct workqueue_struct *ts_workq;
+	struct work_struct pen_event_work;
+	u16 acc_slot;			/* AC97 slot used for acc touch data */
+	u16 acc_rate;			/* acc touch data rate */
+	unsigned pen_is_down:1;		/* Pen is down */
+	unsigned aux_waiting:1;		/* aux measurement waiting */
+	unsigned pen_probably_down:1;	/* used in polling mode */
+};
+
+/*
+ * Codec GPIO access (not supported on WM9705)
+ * This can be used to set/get codec GPIO and Virtual GPIO status.
+ */
+enum wm97xx_gpio_status wm97xx_get_gpio(struct wm97xx *wm, u32 gpio);
+void wm97xx_set_gpio(struct wm97xx *wm, u32 gpio,
+			  enum wm97xx_gpio_status status);
+void wm97xx_config_gpio(struct wm97xx *wm, u32 gpio,
+				     enum wm97xx_gpio_dir dir,
+				     enum wm97xx_gpio_pol pol,
+				     enum wm97xx_gpio_sticky sticky,
+				     enum wm97xx_gpio_wake wake);
+
+/* codec AC97 IO access */
+int wm97xx_reg_read(struct wm97xx *wm, u16 reg);
+void wm97xx_reg_write(struct wm97xx *wm, u16 reg, u16 val);
+
+/* aux adc readback */
+int wm97xx_read_aux_adc(struct wm97xx *wm, u16 adcsel);
+
+/* machine ops */
+int wm97xx_register_mach_ops(struct wm97xx *, struct wm97xx_mach_ops *);
+void wm97xx_unregister_mach_ops(struct wm97xx *);
+
+#endif