path: root/target/linux/ep93xx/patches-3.3/003-ep93xx_touchscreen.patch

---
 arch/arm/mach-ep93xx/include/mach/hardware.h   |    1 
 arch/arm/mach-ep93xx/include/mach/regs_touch.h |   95 ++
 drivers/input/touchscreen/Kconfig              |    5 
 drivers/input/touchscreen/Makefile             |    1 
 drivers/input/touchscreen/ep93xx_ts.c          | 1117 +++++++++++++++++++++++++
 drivers/input/touchscreen/ep93xx_ts.h          |   53 +
 6 files changed, 1272 insertions(+)

--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -200,6 +200,15 @@ config TOUCHSCREEN_EGALAX
 	  To compile this driver as a module, choose M here: the
 	  module will be called egalax_ts.
 
+config TOUCHSCREEN_EP93XX
+	tristate "EP93xx Touchscreen"
+	depends on ARM && INPUT && ARCH_EP93XX
+	help
+	  Say Y here to enable support for EP93xx touch screen.
+
+	  To compile this driver as a module, choose M here:
+	  the module will be called ep93xx_ts.
+
 config TOUCHSCREEN_FUJITSU
 	tristate "Fujitsu serial touchscreen"
 	select SERIO
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_TOUCHSCREEN_GUNZE)		+= gunz
 obj-$(CONFIG_TOUCHSCREEN_EETI)		+= eeti_ts.o
 obj-$(CONFIG_TOUCHSCREEN_ELO)		+= elo.o
 obj-$(CONFIG_TOUCHSCREEN_EGALAX)	+= egalax_ts.o
+obj-$(CONFIG_TOUCHSCREEN_EP93XX)	+= ep93xx_ts.o
 obj-$(CONFIG_TOUCHSCREEN_FUJITSU)	+= fujitsu_ts.o
 obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
 obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o
--- /dev/null
+++ b/drivers/input/touchscreen/ep93xx_ts.c
@@ -0,0 +1,1021 @@
+/*
+ * linux/drivers/input/touchscreen/ep93xx_ts.c
+ *
+ * Copyright (C) 2003-2004 Cirrus Corp.
+ *
+ * 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/types.h>
+#include <linux/delay.h>
+#include <linux/wait.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/poll.h>
+#include <linux/miscdevice.h>
+#include <linux/init.h>
+#include <linux/compiler.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/syscalls.h>
+#include <linux/input.h>
+#include <linux/semaphore.h>
+#include <asm/irq.h>
+#include <mach/hardware.h>
+#include <asm/io.h>
+
+/* This stuff should be in ep93xx-regs.h */
+#define EP93XX_TOUCHSCREEN_REG(x)	(EP93XX_TOUCHSCREEN_BASE + (x))
+/* R/W touchscreen controller setup control register. */
+#define EP93XX_TOUCHSCREEN_SETUP	EP93XX_TOUCHSCREEN_REG(0x00)
+/* R/W touchscreen controller max/min register. */
+#define EP93XX_TOUCHSCREEN_XYMAXMIN	EP93XX_TOUCHSCREEN_REG(0x04)
+/* R   touchscreen controller result register. */
+#define EP93XX_TOUCHSCREEN_XYRESULT	EP93XX_TOUCHSCREEN_REG(0x08)
+/* LOCKED R/W touchscreen Switch Matrix control register. */
+#define EP93XX_TOUCHSCREEN_DISCHARGE	EP93XX_TOUCHSCREEN_REG(0x0C)
+#define EP93XX_TOUCHSCREEN_XSAMPLE	EP93XX_TOUCHSCREEN_REG(0x10)
+#define EP93XX_TOUCHSCREEN_YSAMPLE	EP93XX_TOUCHSCREEN_REG(0x14)
+#define EP93XX_TOUCHSCREEN_DIRECT	EP93XX_TOUCHSCREEN_REG(0x18)
+#define EP93XX_TOUCHSCREEN_DETECT	EP93XX_TOUCHSCREEN_REG(0x1C)
+/*  NA    R/W touchscreen software lock register. */
+#define EP93XX_TOUCHSCREEN_SWLOCK	EP93XX_TOUCHSCREEN_REG(0x20)
+/* R/W touchscreen setup control register #2. */
+#define EP93XX_TOUCHSCREEN_SETUP2	EP93XX_TOUCHSCREEN_REG(0x24)
+
+/* These are duplicated in mach-ep93xx/core.c */
+#define EP93XX_TIMER_REG(x)	(EP93XX_TIMER_BASE + (x))
+#define EP93XX_TIMER2_LOAD	EP93XX_TIMER_REG(0x20)
+#define EP93XX_TIMER2_VALUE	EP93XX_TIMER_REG(0x24)
+#define EP93XX_TIMER2_CONTROL	EP93XX_TIMER_REG(0x28)
+#define EP93XX_TIMER2_CLEAR	EP93XX_TIMER_REG(0x2c)
+
+/*
+ * Register bit definitions
+ */
+#define TSSETUP_SDLY_MASK	0x000003FF
+#define TSSETUP_SDLY_SHIFT	0
+#define TSSETUP_NSMP_4		0x00000000
+#define TSSETUP_NSMP_8		0x00000400
+#define TSSETUP_NSMP_16		0x00000800
+#define TSSETUP_NSMP_32		0x00000C00
+#define TSSETUP_NSMP_MASK	0x00000C00
+#define TSSETUP_DEV_4		0x00000000
+#define TSSETUP_DEV_8		0x00001000
+#define TSSETUP_DEV_12		0x00002000
+#define TSSETUP_DEV_16		0x00003000
+#define TSSETUP_DEV_24		0x00004000
+#define TSSETUP_DEV_32		0x00005000
+#define TSSETUP_DEV_64		0x00006000
+#define TSSETUP_DEV_128		0x00007000
+#define TSSETUP_ENABLE		0x00008000
+#define TSSETUP_DLY_MASK	0x03FF0000
+#define TSSETUP_DLY_SHIFT	16
+#define TSSETUP_TDTCT		0x80000000
+
+#define TSMAXMIN_XMIN_MASK	0x000000FF
+#define TSMAXMIN_XMIN_SHIFT	0
+#define TSMAXMIN_YMIN_MASK	0x0000FF00
+#define TSMAXMIN_YMIN_SHIFT	8
+#define TSMAXMIN_XMAX_MASK	0x00FF0000
+#define TSMAXMIN_XMAX_SHIFT	16
+#define TSMAXMIN_YMAX_MASK	0xFF000000
+#define TSMAXMIN_YMAX_SHIFT	24
+
+#define TSXYRESULT_X_MASK	0x00000FFF
+#define TSXYRESULT_X_SHIFT	0
+#define TSXYRESULT_AD_MASK	0x0000FFFF
+#define TSXYRESULT_AD_SHIFT	0
+#define TSXYRESULT_Y_MASK	0x0FFF0000
+#define TSXYRESULT_Y_SHIFT	16
+#define TSXYRESULT_SDR		0x80000000
+
+#define TSX_SAMPLE_MASK		0x00003FFF
+#define TSX_SAMPLE_SHIFT	0x00
+#define TSY_SAMPLE_MASK		0x3FFF0000
+#define TSY_SAMPLE_SHIFT	0x10
+
+#define TSSETUP2_TINT		0x00000001
+#define TSSETUP2_NICOR		0x00000002
+#define TSSETUP2_PINT		0x00000004
+#define TSSETUP2_PENSTS		0x00000008
+#define TSSETUP2_PINTEN		0x00000010
+#define TSSETUP2_DEVINT		0x00000020
+#define TSSETUP2_DINTEN		0x00000040
+#define TSSETUP2_DTMEN		0x00000080
+#define TSSETUP2_DISDEV		0x00000100
+#define TSSETUP2_NSIGND		0x00000200
+#define TSSETUP2_S28EN		0x00000400
+#define TSSETUP2_RINTEN		0x00000800
+
+#define TSXYRESULT_SDR		0x80000000
+
+/*
+ * These are used as trigger levels to know when we have pen up/down.
+ * The rules:
+ * 1.  TS_HEAVY_INV_PRESSURE < TS_LIGHT_INV_PRESSURE because these
+ *    are Inverse pressure.
+ * 2.  Any touch lighter than TS_LIGHT_INV_PRESSURE is a pen up.
+ * 3.  Any touch heavier than TS_HEAVY_INV_PRESSURE is a pen down.
+ */
+#define TS_HEAVY_INV_PRESSURE 0xFE0 /* C00 */
+#define TS_LIGHT_INV_PRESSURE 0xFFF /* e00 */
+
+/*
+ * If the x, y, or inverse pressure changes more than these values
+ * between two succeeding points, the point is not reported.
+ */
+#define TS_MAX_VALID_XY_CHANGE		0x300
+#define TS_MAX_VALID_PRESSURE_CHANGE	0x100
+
+/*
+ * This is the minimum Z1 Value that is valid.
+ */
+#define MIN_Z1_VALUE 0x50
+
+/*
+ * Settling delay for taking each ADC measurement.  Increase this
+ * if ts is jittery.
+ */
+#define EP93XX_TS_ADC_DELAY_USEC 2000
+
+/*
+ * Delay between TS points.
+ */
+#define EP93XX_TS_PER_POINT_DELAY_USEC 10000
+
+/*
+ * A few more macros...
+ */
+#define TSSETUP_DEFAULT  (TSSETUP_NSMP_32 | TSSETUP_DEV_64 |  \
+			  ((128<<TSSETUP_SDLY_SHIFT) & TSSETUP_SDLY_MASK) | \
+			  ((128<<TSSETUP_DLY_SHIFT)  & TSSETUP_DLY_MASK))
+
+#define TSSETUP2_DEFAULT (TSSETUP2_NSIGND)
+
+/*
+ * For now, we use one of the minor numbers from the local/experimental
+ * range.
+ */
+#define EP93XX_TS_MINOR 240
+
+/*
+ * Static Declarations
+ */
+static unsigned int   guiLastX, guiLastY;
+static unsigned int   guiLastInvPressure;
+
+struct TouchScreenSample
+{
+    int currentX;
+    int currentY;
+    int currentButton;
+    int currentPressure;
+    struct timeval currentTime;
+};
+
+/*
+ * This must match the structure in tslib.
+ */
+struct ts_sample {
+    int x;
+    int y;
+    unsigned int pressure;
+    struct timeval tv;
+};
+
+static struct TouchScreenSample gSample;
+static int bFreshTouchData;
+static int bCurrentPenDown;
+
+static DECLARE_WAIT_QUEUE_HEAD(queue);
+static DEFINE_SEMAPHORE(open_sem);
+static DEFINE_SPINLOCK(event_buffer_lock);
+static struct fasync_struct *ep93xx_fasync;
+
+/*
+ * Typedef Declarations
+ */
+typedef enum {
+    TS_MODE_UN_INITIALIZED,
+    TS_MODE_HARDWARE_SCAN,
+    TS_MODE_SOFT_SCAN
+} ts_mode_t;
+
+static ts_mode_t gScanningMode;
+
+typedef enum{
+    TS_STATE_STOPPED = 0,
+    TS_STATE_Z1,
+    TS_STATE_Z2,
+    TS_STATE_Y,
+    TS_STATE_X,
+    TS_STATE_DONE
+} ts_states_t;
+
+typedef struct
+{
+    unsigned int uiX;
+    unsigned int uiY;
+    unsigned int uiZ1;
+    unsigned int uiZ2;
+    ts_states_t  state;
+} ts_struct_t;
+
+static ts_struct_t sTouch;
+
+/*
+ * From the spec, here's how to set up the touch screen's switch registers.
+ */
+typedef struct
+{
+    unsigned int uiDetect;
+    unsigned int uiDischarge;
+    unsigned int uiXSample;
+    unsigned int uiYSample;
+    unsigned int uiSwitchZ1;
+    unsigned int uiSwitchZ2;
+}SwitchStructType;
+
+/*
+ * Here's the switch settings for a 4-wire touchscreen.  See the spec
+ * for how to handle a 4, 7, or 8-wire.
+ */
+const static SwitchStructType sSwitchSettings =
+/* s28en=0 */
+/*   TSDetect    TSDischarge TSXSample   TSYSample   SwitchZ1    SwitchZ2 */
+    {0x00403604, 0x0007fe04, 0x00081604, 0x00104601, 0x00101601, 0x00101608};
+
+/*
+ * Function declarations
+ */
+static void ep93xx_ts_set_direct(unsigned int uiADCSwitch);
+static irqreturn_t ep93xx_ts_isr(int irq, void *dev_id);
+static irqreturn_t ep93xx_timer2_isr(int irq, void *dev_id);
+static void ee93xx_ts_evt_add(int button, int dX, int dY, int Pressure);
+static ssize_t ep93xx_ts_read(struct file *filp, char *buf,
+	size_t count, loff_t *l);
+static unsigned int ep93xx_ts_poll(struct file *filp, poll_table *wait);
+static int ep93xx_ts_open(struct inode *inode, struct file *filp);
+static int ep93xx_ts_fasync(int fd, struct file *filp, int on);
+static int ep93xx_ts_release(struct inode *inode, struct file *filp);
+static ssize_t ep93xx_ts_write(struct file *file, const char *buffer,
+		size_t count, loff_t *ppos);
+static void ep93xx_ts_setup(void);
+static void ep93xx_ts_shutdown(void);
+int __init ep93xx_ts_init(void);
+void __exit ep93xx_ts_exit(void);
+static unsigned int CalculateInvPressure(void);
+static unsigned int ADCGetData(unsigned int uiSamples, unsigned int uiMaxDiff);
+static void TS_Soft_Scan_Mode(void);
+static void TS_Hardware_Scan_Mode(void);
+static void ProcessPointData(void);
+static void Set_Timer2_uSec(unsigned int Delay_mSec);
+static void Stop_Timer2(void);
+
+/*
+ *  ep93xx_ts_isr
+ */
+static irqreturn_t ep93xx_ts_isr(int irq, void *dev_id)
+{
+    /*
+     * Note that we don't clear the interrupt here.  The interrupt
+     * gets cleared in TS_Soft_Scan_Mode when the TS ENABLE
+     * bit is cleared.
+     */
+
+    /*
+     * Set the ts to manual polling mode and schedule a callback.
+     * That way we can return from the isr in a reasonable amount of
+     * time and process the touch in the callback after a brief delay.
+     */
+    TS_Soft_Scan_Mode();
+
+    return(IRQ_HANDLED);
+}
+
+/*
+ * Save the current ts 'event' in an atomic fashion.
+ */
+static void ee93xx_ts_evt_add(int buttons, int iX, int iY, int iPressure)
+{
+    /*
+     * Note the event, but use spinlocks to keep it from getting
+     * halfway read if we get interrupted.
+     */
+
+    spin_lock(&event_buffer_lock);
+
+    gSample.currentX        = iX;
+    gSample.currentY        = iY;
+    gSample.currentButton   = buttons;
+    gSample.currentPressure = iPressure;
+    bFreshTouchData         = 1;
+    do_gettimeofday(&gSample.currentTime);
+
+    spin_unlock(&event_buffer_lock);
+
+    kill_fasync(&ep93xx_fasync, SIGIO, POLL_IN);
+    wake_up_interruptible(&queue);
+}
+
+
+static ssize_t ep93xx_ts_read(struct file *filp, char *buf, size_t count, loff_t *l)
+{
+    unsigned short data[3];
+    struct  ts_sample   ts_data;
+    int     iReturn = -EFAULT;
+
+    if (!bFreshTouchData)
+    {
+	iReturn = 0;
+    }
+    else if (count == sizeof(data))
+    {
+	spin_lock_irq(&event_buffer_lock);
+	bFreshTouchData = 0;
+	data[0] = gSample.currentX;
+	data[1] = gSample.currentY;
+	data[2] = gSample.currentButton;
+
+	spin_unlock_irq(&event_buffer_lock);
+
+	if (copy_to_user(buf, data, sizeof data))
+	    return -EFAULT;
+
+	count -= sizeof(data);
+
+	/* return the # of bytes that got read */
+	iReturn = sizeof(data) ;
+    }
+    else if (count == sizeof(struct ts_sample) )
+    {
+	spin_lock_irq(&event_buffer_lock);
+	bFreshTouchData = 0;
+	ts_data.x           = gSample.currentX;
+	ts_data.y           = gSample.currentY;
+	ts_data.pressure    = gSample.currentPressure;
+	ts_data.tv          = gSample.currentTime;
+	spin_unlock_irq(&event_buffer_lock);
+
+	if (copy_to_user(buf, &ts_data, sizeof(struct ts_sample)))
+	{
+	    iReturn = -EFAULT;
+	}
+	else
+	{
+	    count -= sizeof(ts_data);
+	    iReturn = sizeof(ts_data);
+	}
+    }
+
+    return iReturn;
+}
+
+static unsigned int ep93xx_ts_poll(struct file *filp, poll_table *wait)
+{
+    poll_wait(filp, &queue, wait);
+
+    if (bFreshTouchData)
+    {
+	return POLLIN | POLLRDNORM;
+    }
+
+    return 0;
+}
+
+static int ep93xx_ts_open(struct inode *inode, struct file *filp)
+{
+    if (down_trylock(&open_sem))
+    {
+	return -EBUSY;
+    }
+
+    ep93xx_ts_setup();
+
+    return 0;
+}
+
+/*
+ * Asynchronous I/O support.
+ */
+static int ep93xx_ts_fasync(int fd, struct file *filp, int on)
+{
+    int retval;
+
+    retval = fasync_helper(fd, filp, on, &ep93xx_fasync);
+    if (retval < 0)
+    {
+	return retval;
+    }
+
+    return 0;
+}
+
+static int ep93xx_ts_release(struct inode *inode, struct file *filp)
+{
+    Stop_Timer2();
+
+    /*
+     * Call our async I/O support to request that this file
+     * cease to be used for async I/O.
+     */
+    ep93xx_ts_fasync(-1, filp, 0);
+
+    ep93xx_ts_shutdown();
+
+    up(&open_sem);
+
+    return 0;
+}
+
+static ssize_t ep93xx_ts_write(struct file *file, const char *buffer, size_t count,
+	       loff_t *ppos)
+{
+    return -EINVAL;
+}
+
+
+static int ep93xx_ts_ioctl(struct inode *inode, struct file *file, uint command, ulong u)
+{
+    static const int         version = EV_VERSION;
+    static const u_int32_t   bit =(1 << EV_ABS);
+    static const u_int32_t   absbit = (1 << ABS_X) | (1 << ABS_Y) | (1 << ABS_PRESSURE);
+    int         iReturn ;
+    int         i = 0;
+
+    switch(command)
+    {
+	case EVIOCGVERSION:
+	    i = copy_to_user((void __user *)u, (void *)version, sizeof(version));
+	    iReturn = i ? -EFAULT : 0;
+	    break;
+
+	case EVIOCGBIT(0,sizeof(u_int32_t) * 8) :
+	    i = copy_to_user((void __user *)u, (void *)bit, sizeof(bit));
+	    iReturn = i ? -EFAULT : 0;
+	    break;
+
+	case EVIOCGBIT(EV_ABS, sizeof(absbit) * 8):
+	    i = copy_to_user((void __user *)u, (void *)absbit, sizeof(absbit));
+	    iReturn = i ? -EFAULT : 0;
+	    break;
+	default:
+	    iReturn = -1;
+	    break;
+    }
+
+    return iReturn;
+}
+
+static struct file_operations ep93xx_ts_fops = {
+    owner:      THIS_MODULE,
+    read:       ep93xx_ts_read,
+    write:      ep93xx_ts_write,
+    poll:       ep93xx_ts_poll,
+    open:       ep93xx_ts_open,
+    unlocked_ioctl:      ep93xx_ts_ioctl,
+    release:    ep93xx_ts_release,
+    fasync:     ep93xx_ts_fasync,
+};
+
+static struct miscdevice ep93xx_ts_miscdev =
+{
+	EP93XX_TS_MINOR,
+	"ep93xx_ts",
+	&ep93xx_ts_fops
+};
+
+void ep93xx_ts_setup(void)
+{
+    unsigned int uiKTDIV, uiTSXYMaxMin;
+
+    /*
+     * Set the TSEN bit in KTDIV so that we are enabling the clock
+     * for the touchscreen.
+     */
+    uiKTDIV = __raw_readl(EP93XX_SYSCON_KEYTCHCLKDIV);
+    uiKTDIV |= EP93XX_SYSCON_KEYTCHCLKDIV_TSEN;
+    ep93xx_syscon_swlocked_write(uiKTDIV, EP93XX_SYSCON_KEYTCHCLKDIV);
+
+    /*
+     * Program the EP93XX_TOUCHSCREEN_SETUP and TSSetup2 registers.
+     */
+    __raw_writel(TSSETUP_DEFAULT, EP93XX_TOUCHSCREEN_SETUP);
+    __raw_writel(TSSETUP2_DEFAULT, EP93XX_TOUCHSCREEN_SETUP2);
+
+    /*
+     * Set the the touch settings.
+     */
+    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
+    __raw_writel(sSwitchSettings.uiDischarge, EP93XX_TOUCHSCREEN_DIRECT);
+
+    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
+    __raw_writel(sSwitchSettings.uiDischarge, EP93XX_TOUCHSCREEN_DISCHARGE);
+
+    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
+    __raw_writel(sSwitchSettings.uiSwitchZ1, EP93XX_TOUCHSCREEN_XSAMPLE);
+
+    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
+    __raw_writel(sSwitchSettings.uiSwitchZ2, EP93XX_TOUCHSCREEN_YSAMPLE);
+
+    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
+    __raw_writel(sSwitchSettings.uiDetect, EP93XX_TOUCHSCREEN_DETECT);
+
+    /*
+     * X,YMin set to 0x40 = have to drag that many pixels for a new irq.
+     * X,YMax set to 0x40 = 1024 pixels is the maximum movement within the
+     * time scan limit.
+     */
+    uiTSXYMaxMin =  (50   << TSMAXMIN_XMIN_SHIFT) & TSMAXMIN_XMIN_MASK;
+    uiTSXYMaxMin |= (50   << TSMAXMIN_YMIN_SHIFT) & TSMAXMIN_YMIN_MASK;
+    uiTSXYMaxMin |= (0xff << TSMAXMIN_XMAX_SHIFT) & TSMAXMIN_XMAX_MASK;
+    uiTSXYMaxMin |= (0xff << TSMAXMIN_YMAX_SHIFT) & TSMAXMIN_YMAX_MASK;
+    __raw_writel(uiTSXYMaxMin, EP93XX_TOUCHSCREEN_XYMAXMIN);
+
+    bCurrentPenDown = 0;
+    bFreshTouchData = 0;
+    guiLastX = 0;
+    guiLastY = 0;
+    guiLastInvPressure = 0xffffff;
+
+    /*
+     * Enable the touch screen scanning engine.
+     */
+    TS_Hardware_Scan_Mode();
+}
+
+/*
+ * ep93xx_ts_shutdown
+ *
+ */
+static void
+ep93xx_ts_shutdown(void)
+{
+    unsigned int uiKTDIV;
+
+    sTouch.state = TS_STATE_STOPPED;
+    Stop_Timer2();
+
+    /*
+     * Disable the scanning engine.
+     */
+    __raw_writel(0, EP93XX_TOUCHSCREEN_SETUP);
+    __raw_writel(0, EP93XX_TOUCHSCREEN_SETUP2);
+
+    /*
+     * Clear the TSEN bit in KTDIV so that we are disabling the clock
+     * for the touchscreen.
+     */
+    uiKTDIV = __raw_readl(EP93XX_SYSCON_KEYTCHCLKDIV);
+    uiKTDIV &= ~EP93XX_SYSCON_KEYTCHCLKDIV_TSEN;
+    ep93xx_syscon_swlocked_write(uiKTDIV, EP93XX_SYSCON_KEYTCHCLKDIV);
+
+} /* ep93xx_ts_shutdown */
+
+static irqreturn_t ep93xx_timer2_isr(int irq, void *dev_id)
+{
+    switch(sTouch.state)
+    {
+	case TS_STATE_STOPPED:
+	    TS_Hardware_Scan_Mode();
+	    break;
+
+	/*
+	 * Get the Z1 value for pressure measurement and set up
+	 * the switch register for getting the Z2 measurement.
+	 */
+	case TS_STATE_Z1:
+	    Set_Timer2_uSec(EP93XX_TS_ADC_DELAY_USEC);
+	    sTouch.uiZ1 = ADCGetData(2, 200);
+	    ep93xx_ts_set_direct(sSwitchSettings.uiSwitchZ2);
+	    sTouch.state = TS_STATE_Z2;
+	    break;
+
+	/*
+	 * Get the Z2 value for pressure measurement and set up
+	 * the switch register for getting the Y measurement.
+	 */
+	case TS_STATE_Z2:
+	    sTouch.uiZ2 = ADCGetData(2, 200);
+	    ep93xx_ts_set_direct(sSwitchSettings.uiYSample);
+	    sTouch.state = TS_STATE_Y;
+	    break;
+
+	/*
+	 * Get the Y value and set up the switch register for
+	 * getting the X measurement.
+	 */
+	case TS_STATE_Y:
+	    sTouch.uiY = ADCGetData(4, 20);
+	    ep93xx_ts_set_direct(sSwitchSettings.uiXSample);
+	    sTouch.state = TS_STATE_X;
+	    break;
+
+	/*
+	 * Read the X value.  This is the last of the 4 adc values
+	 * we need so we continue on to process the data.
+	 */
+	case TS_STATE_X:
+	    Stop_Timer2();
+
+	    sTouch.uiX = ADCGetData(4, 20);
+
+	    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
+	    __raw_writel(sSwitchSettings.uiDischarge, EP93XX_TOUCHSCREEN_DIRECT);
+
+	    sTouch.state = TS_STATE_DONE;
+
+	    /*
+	     * Process this set of ADC readings.
+	     */
+	    ProcessPointData();
+
+	    break;
+
+	/*
+	 * Shouldn't get here.  But if we do, we can recover...
+	 */
+	case TS_STATE_DONE:
+	    TS_Hardware_Scan_Mode();
+	    break;
+    }
+
+    /*
+     * Clear the timer2 interrupt.
+     */
+    __raw_writel(1, EP93XX_TIMER2_CLEAR);
+    return(IRQ_HANDLED);
+}
+
+/*---------------------------------------------------------------------
+ * ProcessPointData
+ *
+ * This routine processes the ADC data into usable point data and then
+ * puts the driver into hw or sw scanning mode before returning.
+ *
+ * We calculate inverse pressure (lower number = more pressure) then
+ * do a hystheresis with the two pressure values 'light' and 'heavy'.
+ *
+ * If we are above the light, we have pen up.
+ * If we are below the heavy we have pen down.
+ * As long as the pressure stays below the light, pen stays down.
+ * When we get above the light again, pen goes back up.
+ *
+ */
+static void ProcessPointData(void)
+{
+    int  bValidPoint = 0;
+    unsigned int   uiXDiff, uiYDiff, uiInvPressureDiff;
+    unsigned int   uiInvPressure;
+
+    /*
+     * Calculate the current pressure.
+     */
+    uiInvPressure = CalculateInvPressure();
+
+    /*
+     * If pen pressure is so light that it is greater than the 'max' setting
+     * then we consider this to be a pen up.
+     */
+    if (uiInvPressure >= TS_LIGHT_INV_PRESSURE)
+    {
+	bCurrentPenDown = 0;
+	ee93xx_ts_evt_add(0, guiLastX, guiLastY, 0);
+	TS_Hardware_Scan_Mode();
+	return;
+    }
+
+    /*
+     * Hysteresis:
+     * If the pen pressure is hard enough to be less than the 'min' OR
+     * the pen is already down and is still less than the 'max'...
+     */
+    if ((uiInvPressure < TS_HEAVY_INV_PRESSURE) ||
+	(bCurrentPenDown && (uiInvPressure < TS_LIGHT_INV_PRESSURE)))
+    {
+	if (bCurrentPenDown)
+	{
+	    /*
+	     * If pen was previously down, check the difference between
+	     * the last sample and this one... if the difference between
+	     * samples is too great, ignore the sample.
+	     */
+	    uiXDiff = abs(guiLastX - sTouch.uiX);
+	    uiYDiff = abs(guiLastY - sTouch.uiY);
+	    uiInvPressureDiff = abs(guiLastInvPressure - uiInvPressure);
+
+	    if (uiXDiff < TS_MAX_VALID_XY_CHANGE
+		&& uiYDiff < TS_MAX_VALID_XY_CHANGE
+		&& uiInvPressureDiff < TS_MAX_VALID_PRESSURE_CHANGE)
+	    {
+		bValidPoint = 1;
+	    }
+	}
+	else
+	{
+	    bValidPoint = 1;
+	}
+
+	/*
+	 * If either the pen was put down or dragged make a note of it.
+	 */
+	if (bValidPoint)
+	{
+	    guiLastX = sTouch.uiX;
+	    guiLastY = sTouch.uiY;
+	    guiLastInvPressure = uiInvPressure;
+	    bCurrentPenDown = 1;
+	    ee93xx_ts_evt_add(1, sTouch.uiX, sTouch.uiY,
+			      0x7000000 / uiInvPressure);
+	}
+
+	TS_Soft_Scan_Mode();
+	return;
+    }
+
+    TS_Hardware_Scan_Mode();
+}
+
+static void ep93xx_ts_set_direct(unsigned int uiADCSwitch)
+{
+    unsigned int uiResult;
+
+    /*
+     * Set the switch settings in the direct register.
+     */
+    __raw_writel(0xaa, EP93XX_TOUCHSCREEN_SWLOCK);
+    __raw_writel(uiADCSwitch, EP93XX_TOUCHSCREEN_DIRECT);
+
+    /*
+     * Read and throw away the first sample.
+     */
+    do {
+	uiResult = __raw_readl(EP93XX_TOUCHSCREEN_XYRESULT);
+    } while (!(uiResult & TSXYRESULT_SDR));
+
+}
+
+static unsigned int ADCGetData(unsigned int uiSamples, unsigned int uiMaxDiff)
+{
+    unsigned int uiResult, uiValue, uiCount, uiLowest, uiHighest, uiSum, uiAve;
+
+    do
+    {
+	/*
+	 * Initialize our values.
+	 */
+	uiLowest        = 0xfffffff;
+	uiHighest       = 0;
+	uiSum           = 0;
+
+	for (uiCount = 0; uiCount < uiSamples; uiCount++)
+	{
+	    /*
+	     * Read the touch screen four more times and average.
+	     */
+	    do {
+		uiResult = __raw_readl(EP93XX_TOUCHSCREEN_XYRESULT);
+	    } while (!(uiResult & TSXYRESULT_SDR));
+
+	    uiValue = (uiResult & TSXYRESULT_AD_MASK) >> TSXYRESULT_AD_SHIFT;
+	    uiValue = ((uiValue >> 4) + ((1 + TSXYRESULT_X_MASK)>>1)) & TSXYRESULT_X_MASK;
+
+	    /*
+	     * Add up the values.
+	     */
+	    uiSum += uiValue;
+
+	    /*
+	     * Get the lowest and highest values.
+	     */
+	    if (uiValue < uiLowest)
+	    {
+		uiLowest = uiValue;
+	    }
+	    if (uiValue > uiHighest)
+	    {
+		uiHighest = uiValue;
+	    }
+	}
+    } while ((uiHighest - uiLowest) > uiMaxDiff);
+
+    /*
+     * Calculate the Average value.
+     */
+    uiAve = uiSum / uiSamples;
+
+    return uiAve;
+}
+
+/*
+ * CalculateInvPressure
+ *
+ * Is the Touch Valid.  Touch is not valid if the X or Y value is not
+ * in range and the pressure is not  enough.
+ *
+ * Touch resistance can be measured by the following formula:
+ *
+ *          Rx * X *     Z2
+ * Rtouch = --------- * (-- - 1)
+ *           4096        Z1
+ *
+ * This is simplified in the ration of Rtouch to Rx.  The lower the value, the
+ * higher the pressure.
+ *
+ *                     Z2
+ * InvPressure =  X * (-- - 1)
+ *                     Z1
+ */
+static unsigned int CalculateInvPressure(void)
+{
+    unsigned int uiInvPressure;
+
+    /*
+     * Check to see if the point is valid.
+     */
+    if (sTouch.uiZ1 < MIN_Z1_VALUE)
+    {
+	uiInvPressure = 0x10000;
+    }
+
+    /*
+     * Can omit the pressure calculation if you need to get rid of the division.
+     */
+    else
+    {
+	uiInvPressure = ((sTouch.uiX * sTouch.uiZ2) / sTouch.uiZ1) - sTouch.uiX;
+    }
+
+    return uiInvPressure;
+}
+
+/*
+ * TS_Hardware_Scan_Mode
+ *
+ * Enables the ep93xx ts scanning engine so that when the pen goes down
+ * we will get an interrupt.
+ */
+static void TS_Hardware_Scan_Mode(void)
+{
+    unsigned int uiDevCfg;
+
+    /*
+     * Disable the soft scanning engine.
+     */
+    sTouch.state = TS_STATE_STOPPED;
+    Stop_Timer2();
+
+    /*
+     * Clear the TIN (Touchscreen INactive) bit so we can go to
+     * automatic scanning mode.
+     */
+    uiDevCfg = __raw_readl(EP93XX_SYSCON_DEVCFG);
+    ep93xx_syscon_swlocked_write(uiDevCfg & ~EP93XX_SYSCON_DEVCFG_TIN,
+				 EP93XX_SYSCON_DEVCFG);
+
+    /*
+     * Enable the touch screen scanning state machine by setting
+     * the ENABLE bit.
+     */
+    __raw_writel(TSSETUP_DEFAULT | TSSETUP_ENABLE, EP93XX_TOUCHSCREEN_SETUP);
+
+    /*
+     * Set the flag to show that we are in interrupt mode.
+     */
+    gScanningMode = TS_MODE_HARDWARE_SCAN;
+
+    /*
+     * Initialize EP93XX_TOUCHSCREEN_SETUP2 register.
+     */
+    __raw_writel(TSSETUP2_DEFAULT, EP93XX_TOUCHSCREEN_SETUP2);
+
+}
+
+/*
+ * TS_Soft_Scan_Mode
+ *
+ * Sets the touch screen to manual polling mode.
+ */
+static void TS_Soft_Scan_Mode(void)
+{
+    unsigned int uiDevCfg;
+
+    if (gScanningMode != TS_MODE_SOFT_SCAN)
+    {
+	/*
+	 * Disable the touch screen scanning state machine by clearing
+	 * the ENABLE bit.
+	 */
+	__raw_writel(TSSETUP_DEFAULT, EP93XX_TOUCHSCREEN_SETUP);
+
+	/*
+	 * Set the TIN bit so we can do manual touchscreen polling.
+	 */
+	uiDevCfg = __raw_readl(EP93XX_SYSCON_DEVCFG);
+	ep93xx_syscon_swlocked_write(uiDevCfg | EP93XX_SYSCON_DEVCFG_TIN,
+				     EP93XX_SYSCON_DEVCFG);
+    }
+
+    /*
+     * Set the switch register up for the first ADC reading
+     */
+    ep93xx_ts_set_direct(sSwitchSettings.uiSwitchZ1);
+
+    /*
+     * Initialize our software state machine to know which ADC
+     * reading to take
+     */
+    sTouch.state = TS_STATE_Z1;
+
+    /*
+     * Set the timer so after a mSec or two settling delay it will
+     * take the first ADC reading.
+     */
+    Set_Timer2_uSec(EP93XX_TS_PER_POINT_DELAY_USEC);
+
+    /*
+     * Note that we are in sw scanning mode not hw scanning mode.
+     */
+    gScanningMode = TS_MODE_SOFT_SCAN;
+
+}
+
+static void Set_Timer2_uSec(unsigned int uiDelay_uSec)
+{
+    unsigned int uiClockTicks;
+
+    /*
+     * Stop timer 2
+     */
+    __raw_writel(0, EP93XX_TIMER2_CONTROL);
+
+    uiClockTicks = ((uiDelay_uSec * 508) + 999) / 1000;
+    __raw_writel(uiClockTicks, EP93XX_TIMER2_LOAD);
+    __raw_writel(uiClockTicks, EP93XX_TIMER2_VALUE);
+
+    /*
+     * Set up Timer 2 for 508 kHz clock and periodic mode.
+     */
+    __raw_writel(0xC8, EP93XX_TIMER2_CONTROL);
+
+}
+
+static void Stop_Timer2(void)
+{
+    __raw_writel(0, EP93XX_TIMER2_CONTROL);
+}
+
+/*
+ * Initialization and exit routines
+ */
+int __init ep93xx_ts_init(void)
+{
+    int retval;
+
+    retval = request_irq(IRQ_EP93XX_TOUCH, ep93xx_ts_isr,
+			 IRQF_DISABLED, "ep93xx_ts", 0);
+    if (retval)
+    {
+	printk(KERN_WARNING "ep93xx_ts: failed to get touchscreen IRQ\n");
+	return retval;
+    }
+
+    retval = request_irq(IRQ_EP93XX_TIMER2, ep93xx_timer2_isr,
+			 IRQF_DISABLED, "ep93xx_timer2", 0);
+    if (retval)
+    {
+	printk(KERN_WARNING "ep93xx_ts: failed to get timer2 IRQ\n");
+	free_irq(IRQ_EP93XX_TOUCH, 0);
+	return retval;
+    }
+
+    misc_register(&ep93xx_ts_miscdev);
+
+    sTouch.state = TS_STATE_STOPPED;
+    gScanningMode = TS_MODE_UN_INITIALIZED;
+
+    printk(KERN_NOTICE "ep93xx touchscreen driver configured for 4-wire operation\n");
+
+    return 0;
+}
+
+void __exit ep93xx_ts_exit(void)
+{
+    Stop_Timer2();
+
+    free_irq(IRQ_EP93XX_TOUCH, 0);
+    free_irq(IRQ_EP93XX_TIMER2, 0);
+
+    misc_deregister(&ep93xx_ts_miscdev);
+}
+
+module_init(ep93xx_ts_init);
+module_exit(ep93xx_ts_exit);
+
+MODULE_DESCRIPTION("Cirrus EP93xx touchscreen driver");
+MODULE_SUPPORTED_DEVICE("touchscreen/ep93xx");
+MODULE_LICENSE("GPL");