Linux 2.6.31 Release for Digi ConnectCore Wi-i.MX boards2.6.31-digi-201102101717

1 files changed, 515 insertions, 642 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index ba9d38c3f412..0f74aeee2aea 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -17,14 +17,11 @@
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  */
-#include <linux/hwmon.h>
+#include <linux/device.h>
 #include <linux/init.h>
-#include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
-#include <linux/slab.h>
-#include <linux/gpio.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/ads7846.h>
 #include <asm/irq.h>
@@ -33,9 +30,7 @@
 /*
  * This code has been heavily tested on a Nokia 770, and lightly
  * tested on other ads7846 devices (OSK/Mistral, Lubbock).
- * TSC2046 is just newer ads7846 silicon.
- * Support for ads7843 tested on Atmel at91sam926x-EK.
- * Support for ads7845 has only been stubbed in.
+ * Support for ads7843 and ads7845 has only been stubbed in.
  *
  * IRQ handling needs a workaround because of a shortcoming in handling
  * edge triggered IRQs on some platforms like the OMAP1/2. These
@@ -51,8 +46,7 @@
  * files.
  */
 
-#define TS_POLL_DELAY	(1 * 1000000)	/* ns delay before the first sample */
-#define TS_POLL_PERIOD	(5 * 1000000)	/* ns delay between samples */
+#define	TS_POLL_PERIOD	msecs_to_jiffies(10)
 
 /* this driver doesn't aim at the peak continuous sample rate */
 #define	SAMPLE_BITS	(8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
@@ -61,77 +55,57 @@ struct ts_event {
 	/* For portability, we can't read 12 bit values using SPI (which
 	 * would make the controller deliver them as native byteorder u16
 	 * with msbs zeroed).  Instead, we read them as two 8-bit values,
-	 * *** WHICH NEED BYTESWAPPING *** and range adjustment.
+	 * which need byteswapping then range adjustment.
 	 */
-	u16	x;
-	u16	y;
-	u16	z1, z2;
-	int	ignore;
-};
-
-/*
- * We allocate this separately to avoid cache line sharing issues when
- * driver is used with DMA-based SPI controllers (like atmel_spi) on
- * systems where main memory is not DMA-coherent (most non-x86 boards).
- */
-struct ads7846_packet {
-	u8			read_x, read_y, read_z1, read_z2, pwrdown;
-	u16			dummy;		/* for the pwrdown read */
-	struct ts_event		tc;
+	__be16 x;
+	__be16 y;
+	__be16 z1, z2;
+	int    ignore;
 };
 
 struct ads7846 {
 	struct input_dev	*input;
 	char			phys[32];
-	char			name[32];
 
-	struct spi_device	*spi;
-
-#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
-	struct attribute_group	*attr_group;
-	struct device		*hwmon;
-#endif
+	u32			*txbuf;
+	u32			*rxbuf;
+	u8			buflen;
+	u8			skip_samples;
+	u16			rotate;
 
+	struct spi_device	*spi;
 	u16			model;
-	u16			vref_mv;
 	u16			vref_delay_usecs;
 	u16			x_plate_ohms;
 	u16			pressure_max;
 
-	bool			swap_xy;
-
-	struct ads7846_packet	*packet;
+	u8			read_x, read_y, read_z1, read_z2, pwrdown;
+	u16                     zerro;          /* to send zerros while receiving */
+	u16			dummy;		/* for the pwrdown read */
+	struct ts_event		tc;
 
-	struct spi_transfer	xfer[18];
+	struct spi_transfer	xfer[10];
 	struct spi_message	msg[5];
 	struct spi_message	*last_msg;
 	int			msg_idx;
 	int			read_cnt;
 	int			read_rep;
 	int			last_read;
+	int			skip_this_sample;
 
 	u16			debounce_max;
 	u16			debounce_tol;
 	u16			debounce_rep;
 
-	u16			penirq_recheck_delay_usecs;
-
 	spinlock_t		lock;
-	struct hrtimer		timer;
+	struct timer_list	timer;		/* P: lock */
 	unsigned		pendown:1;	/* P: lock */
 	unsigned		pending:1;	/* P: lock */
 // FIXME remove "irq_disabled"
 	unsigned		irq_disabled:1;	/* P: lock */
 	unsigned		disabled:1;
-	unsigned		is_suspended:1;
 
-	int			(*filter)(void *data, int data_idx, int *val);
-	void			*filter_data;
-	void			(*filter_cleanup)(void *data);
 	int			(*get_pendown_state)(void);
-	int			gpio_pendown;
-
-	void			(*wait_for_sync)(void);
 };
 
 /* leave chip selected when we're done, for quicker re-select? */
@@ -141,6 +115,7 @@ struct ads7846 {
 #define	CS_CHANGE(xfer)	((xfer).cs_change = 0)
 #endif
 
+
 /*--------------------------------------------------------------------------*/
 
 /* The ADS7846 has touchscreen and other sensors.
@@ -167,16 +142,19 @@ struct ads7846 {
 #define	MAX_12BIT	((1<<12)-1)
 
 /* leave ADC powered up (disables penirq) between differential samples */
-#define	READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
-	| ADS_12_BIT | ADS_DFR | \
-	(adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
+#define	READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
+	| ADS_12_BIT | ADS_DFR)
+
+#define	READ_Y	(READ_12BIT_DFR(y)  | ADS_PD10_ADC_ON)
+#define	READ_Z1	(READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON)
+#define	READ_Z2	(READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON)
 
-#define	READ_Y(vref)	(READ_12BIT_DFR(y,  1, vref))
-#define	READ_Z1(vref)	(READ_12BIT_DFR(z1, 1, vref))
-#define	READ_Z2(vref)	(READ_12BIT_DFR(z2, 1, vref))
+#define	READ_X	(READ_12BIT_DFR(x)  | ADS_PD10_ADC_ON)
+#define	PWRDOWN	(READ_12BIT_DFR(y)  | ADS_PD10_PDOWN)	/* LAST */
 
-#define	READ_X(vref)	(READ_12BIT_DFR(x,  1, vref))
-#define	PWRDOWN		(READ_12BIT_DFR(y,  0, 0))	/* LAST */
+/* alternate ads7843 commands */
+#define	ALT_READ_Y      (READ_12BIT_DFR(y)  | ADS_PD10_ALL_ON)
+#define	ALT_READ_X      (READ_12BIT_DFR(x)  | ADS_PD10_ALL_ON)
 
 /* single-ended samples need to first power up reference voltage;
  * we leave both ADC and VREF powered
@@ -184,15 +162,21 @@ struct ads7846 {
 #define	READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
 	| ADS_12_BIT | ADS_SER)
 
-#define	REF_ON	(READ_12BIT_DFR(x, 1, 1))
-#define	REF_OFF	(READ_12BIT_DFR(y, 0, 0))
+#define	REF_ON	(READ_12BIT_DFR(x) | ADS_PD10_ALL_ON)
+#define	REF_OFF	(READ_12BIT_DFR(y) | ADS_PD10_PDOWN)
+
+#define	MAX_BUF_SAMPLE_LEN	(20)
+/* Following configuration should be done in the platform configuration */
+#define	SCREEN_LANDSCAPE	1
+#undef	SCREEN_PORTRAIT
+#define MAX_DIFF_BETWEEN_SAMPLES_X	100
+#define MAX_DIFF_BETWEEN_SAMPLES_Y	100
+
 
 /*--------------------------------------------------------------------------*/
 
 /*
  * Non-touchscreen sensors only use single-ended conversions.
- * The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
- * ads7846 lets that pin be unconnected, to use internal vREF.
  */
 
 struct ser_req {
@@ -200,6 +184,7 @@ struct ser_req {
 	u8			command;
 	u8			ref_off;
 	u16			scratch;
+	u16                     zerro;
 	__be16			sample;
 	struct spi_message	msg;
 	struct spi_transfer	xfer[6];
@@ -211,247 +196,132 @@ static void ads7846_disable(struct ads7846 *ts);
 static int device_suspended(struct device *dev)
 {
 	struct ads7846 *ts = dev_get_drvdata(dev);
-	return ts->is_suspended || ts->disabled;
+	return dev->power.power_state.event != PM_EVENT_ON || ts->disabled;
 }
 
+static int ads7843_setup_buffers(struct device *dev)
+{
+	struct ads7846		*ts = dev_get_drvdata(dev);
+	int i;
+
+	ts->txbuf = kzalloc(sizeof(u32) * ts->buflen * 3, GFP_KERNEL);
+	if (!ts->txbuf)
+		return -ENOMEM;
+
+	ts->rxbuf = kzalloc(sizeof(u32) * ts->buflen * 3, GFP_KERNEL);
+	if (!ts->rxbuf) {
+		kfree(ts->txbuf);
+		return -ENOMEM;
+	}
+	for (i = 0; i < ((ts->buflen * 3) / 2); i++)
+#if defined( SCREEN_LANDSCAPE )
+		ts->txbuf[i] = (READ_12BIT_DFR(x) | ADS_PD10_PDOWN) << 8;
+#else
+		ts->txbuf[i] = (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) << 8;
+#endif
+	for (; i < ts->buflen * 3; i++)
+#if defined( SCREEN_LANDSCAPE )
+		ts->txbuf[i] = (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) << 8;
+#else
+		ts->txbuf[i] = (READ_12BIT_DFR(x) | ADS_PD10_PDOWN) << 8;
+#endif
+	return 0;
+}
+
+
 static int ads7846_read12_ser(struct device *dev, unsigned command)
 {
 	struct spi_device	*spi = to_spi_device(dev);
 	struct ads7846		*ts = dev_get_drvdata(dev);
 	struct ser_req		*req = kzalloc(sizeof *req, GFP_KERNEL);
 	int			status;
-	int			use_internal;
+	int			sample;
+	int			i;
 
 	if (!req)
 		return -ENOMEM;
 
 	spi_message_init(&req->msg);
 
-	/* FIXME boards with ads7846 might use external vref instead ... */
-	use_internal = (ts->model == 7846);
-
-	/* maybe turn on internal vREF, and let it settle */
-	if (use_internal) {
-		req->ref_on = REF_ON;
-		req->xfer[0].tx_buf = &req->ref_on;
-		req->xfer[0].len = 1;
-		spi_message_add_tail(&req->xfer[0], &req->msg);
-
-		req->xfer[1].rx_buf = &req->scratch;
-		req->xfer[1].len = 2;
-
-		/* for 1uF, settle for 800 usec; no cap, 100 usec.  */
-		req->xfer[1].delay_usecs = ts->vref_delay_usecs;
-		spi_message_add_tail(&req->xfer[1], &req->msg);
-	}
+	/* activate reference, so it has time to settle; */
+	req->ref_on = REF_ON;
+	req->xfer[0].tx_buf = &req->ref_on;
+	req->xfer[0].len = 1;
+	req->xfer[1].tx_buf = &req->zerro;
+	req->xfer[1].rx_buf = &req->scratch;
+	req->xfer[1].len = 2;
+
+	/*
+	 * for external VREF, 0 usec (and assume it's always on);
+	 * for 1uF, use 800 usec;
+	 * no cap, 100 usec.
+	 */
+	req->xfer[1].delay_usecs = ts->vref_delay_usecs;
 
 	/* take sample */
 	req->command = (u8) command;
 	req->xfer[2].tx_buf = &req->command;
 	req->xfer[2].len = 1;
-	spi_message_add_tail(&req->xfer[2], &req->msg);
-
+	req->xfer[3].tx_buf = &req->zerro;
 	req->xfer[3].rx_buf = &req->sample;
 	req->xfer[3].len = 2;
-	spi_message_add_tail(&req->xfer[3], &req->msg);
 
 	/* REVISIT:  take a few more samples, and compare ... */
 
-	/* converter in low power mode & enable PENIRQ */
-	req->ref_off = PWRDOWN;
+	/* turn off reference */
+	req->ref_off = REF_OFF;
 	req->xfer[4].tx_buf = &req->ref_off;
 	req->xfer[4].len = 1;
-	spi_message_add_tail(&req->xfer[4], &req->msg);
-
+	// TODO req->xfer[3].tx_buf = &req->zerro;
+	req->xfer[5].tx_buf = &req->zerro;
 	req->xfer[5].rx_buf = &req->scratch;
 	req->xfer[5].len = 2;
+
 	CS_CHANGE(req->xfer[5]);
-	spi_message_add_tail(&req->xfer[5], &req->msg);
+
+	/* group all the transfers together, so we can't interfere with
+	 * reading touchscreen state; disable penirq while sampling
+	 */
+	for (i = 0; i < 6; i++)
+		spi_message_add_tail(&req->xfer[i], &req->msg);
 
 	ts->irq_disabled = 1;
-	disable_irq(spi->irq);
+	disable_irq_nosync(spi->irq);
 	status = spi_sync(spi, &req->msg);
 	ts->irq_disabled = 0;
 	enable_irq(spi->irq);
 
-	if (status == 0) {
-		/* on-wire is a must-ignore bit, a BE12 value, then padding */
-		status = be16_to_cpu(req->sample);
-		status = status >> 3;
-		status &= 0x0fff;
-	}
+	if (req->msg.status)
+		status = req->msg.status;
+
+	/* on-wire is a must-ignore bit, a BE12 value, then padding */
+	sample = be16_to_cpu(req->sample);
+	sample = sample >> 3;
+	sample &= 0x0fff;
 
 	kfree(req);
-	return status;
+	return status ? status : sample;
 }
 
-#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
-
-#define SHOW(name, var, adjust) static ssize_t \
+#define SHOW(name) static ssize_t \
 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 { \
-	struct ads7846 *ts = dev_get_drvdata(dev); \
 	ssize_t v = ads7846_read12_ser(dev, \
-			READ_12BIT_SER(var) | ADS_PD10_ALL_ON); \
+			READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \
 	if (v < 0) \
 		return v; \
-	return sprintf(buf, "%u\n", adjust(ts, v)); \
+	return sprintf(buf, "%u\n", (unsigned) v); \
 } \
 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 
-
-/* Sysfs conventions report temperatures in millidegrees Celsius.
- * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
- * accuracy scheme without calibration data.  For now we won't try either;
- * userspace sees raw sensor values, and must scale/calibrate appropriately.
- */
-static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
-{
-	return v;
-}
-
-SHOW(temp0, temp0, null_adjust)		/* temp1_input */
-SHOW(temp1, temp1, null_adjust)		/* temp2_input */
-
-
-/* sysfs conventions report voltages in millivolts.  We can convert voltages
- * if we know vREF.  userspace may need to scale vAUX to match the board's
- * external resistors; we assume that vBATT only uses the internal ones.
- */
-static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
-{
-	unsigned retval = v;
-
-	/* external resistors may scale vAUX into 0..vREF */
-	retval *= ts->vref_mv;
-	retval = retval >> 12;
-	return retval;
-}
-
-static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
-{
-	unsigned retval = vaux_adjust(ts, v);
-
-	/* ads7846 has a resistor ladder to scale this signal down */
-	if (ts->model == 7846)
-		retval *= 4;
-	return retval;
-}
-
-SHOW(in0_input, vaux, vaux_adjust)
-SHOW(in1_input, vbatt, vbatt_adjust)
-
-
-static struct attribute *ads7846_attributes[] = {
-	&dev_attr_temp0.attr,
-	&dev_attr_temp1.attr,
-	&dev_attr_in0_input.attr,
-	&dev_attr_in1_input.attr,
-	NULL,
-};
-
-static struct attribute_group ads7846_attr_group = {
-	.attrs = ads7846_attributes,
-};
-
-static struct attribute *ads7843_attributes[] = {
-	&dev_attr_in0_input.attr,
-	&dev_attr_in1_input.attr,
-	NULL,
-};
-
-static struct attribute_group ads7843_attr_group = {
-	.attrs = ads7843_attributes,
-};
-
-static struct attribute *ads7845_attributes[] = {
-	&dev_attr_in0_input.attr,
-	NULL,
-};
-
-static struct attribute_group ads7845_attr_group = {
-	.attrs = ads7845_attributes,
-};
-
-static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
-{
-	struct device *hwmon;
-	int err;
-
-	/* hwmon sensors need a reference voltage */
-	switch (ts->model) {
-	case 7846:
-		if (!ts->vref_mv) {
-			dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
-			ts->vref_mv = 2500;
-		}
-		break;
-	case 7845:
-	case 7843:
-		if (!ts->vref_mv) {
-			dev_warn(&spi->dev,
-				"external vREF for ADS%d not specified\n",
-				ts->model);
-			return 0;
-		}
-		break;
-	}
-
-	/* different chips have different sensor groups */
-	switch (ts->model) {
-	case 7846:
-		ts->attr_group = &ads7846_attr_group;
-		break;
-	case 7845:
-		ts->attr_group = &ads7845_attr_group;
-		break;
-	case 7843:
-		ts->attr_group = &ads7843_attr_group;
-		break;
-	default:
-		dev_dbg(&spi->dev, "ADS%d not recognized\n", ts->model);
-		return 0;
-	}
-
-	err = sysfs_create_group(&spi->dev.kobj, ts->attr_group);
-	if (err)
-		return err;
-
-	hwmon = hwmon_device_register(&spi->dev);
-	if (IS_ERR(hwmon)) {
-		sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
-		return PTR_ERR(hwmon);
-	}
-
-	ts->hwmon = hwmon;
-	return 0;
-}
-
-static void ads784x_hwmon_unregister(struct spi_device *spi,
-				     struct ads7846 *ts)
-{
-	if (ts->hwmon) {
-		sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
-		hwmon_device_unregister(ts->hwmon);
-	}
-}
-
-#else
-static inline int ads784x_hwmon_register(struct spi_device *spi,
-					 struct ads7846 *ts)
-{
-	return 0;
-}
-
-static inline void ads784x_hwmon_unregister(struct spi_device *spi,
-					    struct ads7846 *ts)
-{
-}
-#endif
+SHOW(temp0)
+SHOW(temp1)
+SHOW(vaux)
+SHOW(vbatt)
 
 static int is_pen_down(struct device *dev)
 {
-	struct ads7846	*ts = dev_get_drvdata(dev);
+	struct ads7846		*ts = dev_get_drvdata(dev);
 
 	return ts->pendown;
 }
@@ -477,11 +347,10 @@ static ssize_t ads7846_disable_store(struct device *dev,
 				     const char *buf, size_t count)
 {
 	struct ads7846 *ts = dev_get_drvdata(dev);
-	unsigned long i;
-
-	if (strict_strtoul(buf, 10, &i))
-		return -EINVAL;
+	char *endp;
+	int i;
 
+	i = simple_strtoul(buf, &endp, 10);
 	spin_lock_irq(&ts->lock);
 
 	if (i)
@@ -496,30 +365,8 @@ static ssize_t ads7846_disable_store(struct device *dev,
 
 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
 
-static struct attribute *ads784x_attributes[] = {
-	&dev_attr_pen_down.attr,
-	&dev_attr_disable.attr,
-	NULL,
-};
-
-static struct attribute_group ads784x_attr_group = {
-	.attrs = ads784x_attributes,
-};
-
 /*--------------------------------------------------------------------------*/
 
-static int get_pendown_state(struct ads7846 *ts)
-{
-	if (ts->get_pendown_state)
-		return ts->get_pendown_state();
-
-	return !gpio_get_value(ts->gpio_pendown);
-}
-
-static void null_wait_for_sync(void)
-{
-}
-
 /*
  * PENIRQ only kicks the timer.  The timer only reissues the SPI transfer,
  * to retrieve touchscreen status.
@@ -531,25 +378,25 @@ static void null_wait_for_sync(void)
 static void ads7846_rx(void *ads)
 {
 	struct ads7846		*ts = ads;
-	struct ads7846_packet	*packet = ts->packet;
+	struct input_dev	*input_dev = ts->input;
 	unsigned		Rt;
+	unsigned		sync = 0;
 	u16			x, y, z1, z2;
+	unsigned long		flags;
 
-	/* ads7846_rx_val() did in-place conversion (including byteswap) from
-	 * on-the-wire format as part of debouncing to get stable readings.
+	/* adjust:  on-wire is a must-ignore bit, a BE12 value, then padding;
+	 * built from two 8 bit values written msb-first.
 	 */
-	x = packet->tc.x;
-	y = packet->tc.y;
-	z1 = packet->tc.z1;
-	z2 = packet->tc.z2;
+	x = (be16_to_cpu(ts->tc.x) >> 3) & 0x0fff;
+	y = (be16_to_cpu(ts->tc.y) >> 3) & 0x0fff;
+	z1 = (be16_to_cpu(ts->tc.z1) >> 3) & 0x0fff;
+	z2 = (be16_to_cpu(ts->tc.z2) >> 3) & 0x0fff;
 
 	/* range filtering */
 	if (x == MAX_12BIT)
 		x = 0;
 
-	if (ts->model == 7843) {
-		Rt = ts->pressure_max / 2;
-	} else if (likely(x && z1)) {
+	if (likely(x && z1 && !device_suspended(&ts->spi->dev))) {
 		/* compute touch pressure resistance using equation #2 */
 		Rt = z2;
 		Rt -= z1;
@@ -557,194 +404,281 @@ static void ads7846_rx(void *ads)
 		Rt *= ts->x_plate_ohms;
 		Rt /= z1;
 		Rt = (Rt + 2047) >> 12;
-	} else {
+	} else
 		Rt = 0;
-	}
 
 	/* Sample found inconsistent by debouncing or pressure is beyond
-	 * the maximum. Don't report it to user space, repeat at least
-	 * once more the measurement
-	 */
-	if (packet->tc.ignore || Rt > ts->pressure_max) {
-#ifdef VERBOSE
-		pr_debug("%s: ignored %d pressure %d\n",
-			dev_name(&ts->spi->dev), packet->tc.ignore, Rt);
-#endif
-		hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
-			      HRTIMER_MODE_REL);
+	* the maximum. Don't report it to user space, repeat at least
+	* once more the measurement */
+	if (ts->tc.ignore || Rt > ts->pressure_max) {
+		mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
 		return;
 	}
 
-	/* Maybe check the pendown state before reporting. This discards
-	 * false readings when the pen is lifted.
+	/* NOTE:  "pendown" is inferred from pressure; we don't rely on
+	 * being able to check nPENIRQ status, or "friendly" trigger modes
+	 * (both-edges is much better than just-falling or low-level).
+	 *
+	 * REVISIT:  some boards may require reading nPENIRQ; it's
+	 * needed on 7843.  and 7845 reads pressure differently...
+	 *
+	 * REVISIT:  the touchscreen might not be connected; this code
+	 * won't notice that, even if nPENIRQ never fires ...
 	 */
-	if (ts->penirq_recheck_delay_usecs) {
-		udelay(ts->penirq_recheck_delay_usecs);
-		if (!get_pendown_state(ts))
-			Rt = 0;
+	if (!ts->pendown && Rt != 0) {
+		input_report_key(input_dev, BTN_TOUCH, 1);
+		sync = 1;
+	} else if (ts->pendown && Rt == 0) {
+		input_report_key(input_dev, BTN_TOUCH, 0);
+		sync = 1;
 	}
 
-	/* NOTE: We can't rely on the pressure to determine the pen down
-	 * state, even this controller has a pressure sensor.  The pressure
-	 * value can fluctuate for quite a while after lifting the pen and
-	 * in some cases may not even settle at the expected value.
-	 *
-	 * The only safe way to check for the pen up condition is in the
-	 * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
-	 */
 	if (Rt) {
-		struct input_dev *input = ts->input;
+		input_report_abs(input_dev, ABS_X, x);
+		input_report_abs(input_dev, ABS_Y, y);
+		sync = 1;
+	}
 
-		if (!ts->pendown) {
-			input_report_key(input, BTN_TOUCH, 1);
-			ts->pendown = 1;
-#ifdef VERBOSE
-			dev_dbg(&ts->spi->dev, "DOWN\n");
+	if (sync) {
+		input_report_abs(input_dev, ABS_PRESSURE, Rt);
+		input_sync(input_dev);
+	}
+
+#ifdef	VERBOSE
+	if (Rt || ts->pendown)
+		pr_debug("%s: %d/%d/%d%s\n", dev_name(&ts->spi->dev),
+			x, y, Rt, Rt ? "" : " UP");
 #endif
+
+	spin_lock_irqsave(&ts->lock, flags);
+
+	ts->pendown = (Rt != 0);
+	mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
+
+	spin_unlock_irqrestore(&ts->lock, flags);
+}
+
+static inline u16 ad7843_get_sample_val(u32 sample)
+{
+	return (((((sample & 0x00ff0000) >> 8) | (sample >> 24)) >> 3) & 0x0fff);
+}
+
+static u32 ad7843_get_better_values(struct ads7846 *ts, int index, int skiplimit)
+{
+	u32 diff12, diff23, diff31;
+	u32 vals[3];
+	int i;
+
+	for (i = 0; i < 3; i++) {
+		vals[i] = ad7843_get_sample_val(ts->rxbuf[index+i]);
+		if (vals[i] == 0x0fff || vals[i] == 0) {
+			ts->skip_this_sample = 1;
+			return 0;
 		}
+	}
 
-		if (ts->swap_xy)
-			swap(x, y);
+	diff12 = (vals[0] > vals[1]) ? vals[0] - vals[1] : vals[1] - vals[0];
+	if (diff12 > skiplimit) {
+		ts->skip_this_sample = 1;
+		return 0;
+	}
 
-		input_report_abs(input, ABS_X, x);
-		input_report_abs(input, ABS_Y, y);
-		input_report_abs(input, ABS_PRESSURE, Rt);
+	diff23 = (vals[1] > vals[2]) ? vals[1] - vals[2] : vals[2] - vals[1];
+	if (diff23 > skiplimit) {
+		ts->skip_this_sample = 1;
+		return 0;
+	}
 
-		input_sync(input);
-#ifdef VERBOSE
-		dev_dbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
-#endif
+	diff31 = (vals[2] > vals[0]) ? vals[2] - vals[0] : vals[0] - vals[2];
+	if (diff31 > skiplimit) {
+		ts->skip_this_sample = 1;
+		return 0;
 	}
 
-	hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
-			HRTIMER_MODE_REL);
+	if (diff12 < diff23 && diff12 < diff31)
+		return (vals[0] + vals[1]) / 2;
+	if (diff23 < diff12 && diff23 < diff31)
+		return (vals[1] + vals[2]) / 2;
+
+	return (vals[0] + vals[2]) / 2;
 }
 
-static int ads7846_debounce(void *ads, int data_idx, int *val)
+static void ads7843_rx_average(void *ads)
+{
+	struct ads7846          *ts = ads;
+	struct input_dev        *input_dev = ts->input;
+	u16                     x, y, temp;
+	unsigned long           flags;
+	int i, sample_count;
+
+	dev_dbg(&ts->spi->dev, "%s\n", __FUNCTION__);
+
+	for (i = 0, y = 0, x = 0, sample_count = 0; i < (ts->buflen * 3 / 2); i+=3) {
+		if (i >= ts->skip_samples*3) {
+			temp = ad7843_get_better_values(ts, i, MAX_DIFF_BETWEEN_SAMPLES_Y);
+			if (!ts->skip_this_sample) {
+				if (ts->rotate == 180) {
+					y += MAX_12BIT - temp;
+				} else if (ts->rotate == 0) {
+					y += temp;
+				} else {
+					dev_info(&ts->spi->dev,
+						 "Rotate mode %d, not implemented yet\n",
+						 ts->rotate);
+				}
+				sample_count++;
+			}
+		}
+		ts->skip_this_sample = 0;
+	}
+
+	if (!sample_count)
+		goto sample_taken;
+
+	y /= sample_count;
+
+	for (sample_count = 0; i < (ts->buflen * 3); i+=3) {
+		if (i >= (ts->skip_samples + ts->buflen / 2)*3) {
+			temp = ad7843_get_better_values(ts, i, MAX_DIFF_BETWEEN_SAMPLES_X);
+			if (!ts->skip_this_sample) {
+				if (ts->rotate == 180) {
+					x += MAX_12BIT - temp;
+				} else if (ts->rotate == 0) {
+					x += temp;
+				} else {
+					dev_info(&ts->spi->dev,
+						 "Rotate mode %d, not implemented yet\n",
+						 ts->rotate);
+				}
+				sample_count++;
+			}
+		}
+		ts->skip_this_sample = 0;
+	}
+
+	if (!sample_count)
+		goto sample_taken;
+
+	x /= sample_count;
+
+       if (ts->pendown) {
+
+               input_report_key(input_dev, BTN_TOUCH, 1);
+               input_report_abs(input_dev, ABS_PRESSURE, ts->pressure_max / 2);
+               input_report_abs(input_dev, ABS_X, x);
+               input_report_abs(input_dev, ABS_Y, y);
+       } else {
+               input_report_key(input_dev, BTN_TOUCH, 0);
+               input_report_abs(input_dev, ABS_PRESSURE, 0);
+       }
+
+       input_sync(input_dev);
+       dev_dbg(&ts->spi->dev, "%d/%d %s\n", x, y, ts->pendown ? "" : " UP");
+
+sample_taken:
+       if (ts->pendown) {
+               spin_lock_irqsave(&ts->lock, flags);
+               mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
+               spin_unlock_irqrestore(&ts->lock, flags);
+       }
+}
+
+static void ads7846_debounce(void *ads)
 {
 	struct ads7846		*ts = ads;
+	struct spi_message	*m;
+	struct spi_transfer	*t;
+	int			val;
+	int			status;
 
-	if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
-		/* Start over collecting consistent readings. */
-		ts->read_rep = 0;
+	m = &ts->msg[ts->msg_idx];
+	t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
+	val = (be16_to_cpu(*(__be16 *)t->rx_buf) >> 3) & 0x0fff;
+	if (!ts->read_cnt || (abs(ts->last_read - val) > ts->debounce_tol)) {
 		/* Repeat it, if this was the first read or the read
 		 * wasn't consistent enough. */
 		if (ts->read_cnt < ts->debounce_max) {
-			ts->last_read = *val;
+			ts->last_read = val;
 			ts->read_cnt++;
-			return ADS7846_FILTER_REPEAT;
 		} else {
 			/* Maximum number of debouncing reached and still
 			 * not enough number of consistent readings. Abort
 			 * the whole sample, repeat it in the next sampling
 			 * period.
 			 */
+			ts->tc.ignore = 1;
 			ts->read_cnt = 0;
-			return ADS7846_FILTER_IGNORE;
+			/* Last message will contain ads7846_rx() as the
+			 * completion function.
+			 */
+			m = ts->last_msg;
 		}
+		/* Start over collecting consistent readings. */
+		ts->read_rep = 0;
 	} else {
 		if (++ts->read_rep > ts->debounce_rep) {
 			/* Got a good reading for this coordinate,
 			 * go for the next one. */
+			ts->tc.ignore = 0;
+			ts->msg_idx++;
 			ts->read_cnt = 0;
 			ts->read_rep = 0;
-			return ADS7846_FILTER_OK;
-		} else {
+			m++;
+		} else
 			/* Read more values that are consistent. */
 			ts->read_cnt++;
-			return ADS7846_FILTER_REPEAT;
-		}
 	}
-}
-
-static int ads7846_no_filter(void *ads, int data_idx, int *val)
-{
-	return ADS7846_FILTER_OK;
-}
-
-static void ads7846_rx_val(void *ads)
-{
-	struct ads7846 *ts = ads;
-	struct ads7846_packet *packet = ts->packet;
-	struct spi_message *m;
-	struct spi_transfer *t;
-	int val;
-	int action;
-	int status;
-
-	m = &ts->msg[ts->msg_idx];
-	t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
-
-	/* adjust:  on-wire is a must-ignore bit, a BE12 value, then padding;
-	 * built from two 8 bit values written msb-first.
-	 */
-	val = be16_to_cpup((__be16 *)t->rx_buf) >> 3;
-
-	action = ts->filter(ts->filter_data, ts->msg_idx, &val);
-	switch (action) {
-	case ADS7846_FILTER_REPEAT:
-		break;
-	case ADS7846_FILTER_IGNORE:
-		packet->tc.ignore = 1;
-		/* Last message will contain ads7846_rx() as the
-		 * completion function.
-		 */
-		m = ts->last_msg;
-		break;
-	case ADS7846_FILTER_OK:
-		*(u16 *)t->rx_buf = val;
-		packet->tc.ignore = 0;
-		m = &ts->msg[++ts->msg_idx];
-		break;
-	default:
-		BUG();
-	}
-	ts->wait_for_sync();
 	status = spi_async(ts->spi, m);
 	if (status)
 		dev_err(&ts->spi->dev, "spi_async --> %d\n",
 				status);
 }
 
-static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
+static void ads7846_timer(unsigned long handle)
 {
-	struct ads7846	*ts = container_of(handle, struct ads7846, timer);
-	int		status = 0;
+	struct ads7846		*ts = (void *)handle;
+	struct input_dev        *input_dev = ts->input;
+	int			status = 0;
 
-	spin_lock(&ts->lock);
-
-	if (unlikely(!get_pendown_state(ts) ||
-		     device_suspended(&ts->spi->dev))) {
-		if (ts->pendown) {
-			struct input_dev *input = ts->input;
-
-			input_report_key(input, BTN_TOUCH, 0);
-			input_report_abs(input, ABS_PRESSURE, 0);
-			input_sync(input);
+	/* get sample */
+	ts->pendown = ts->get_pendown_state();
+	spin_lock_irq(&ts->lock);
+	if (ts->model == 7843) {
+		ts->pending = 0;
+		if (unlikely(!ts->pendown)) {
 
-			ts->pendown = 0;
-#ifdef VERBOSE
-			dev_dbg(&ts->spi->dev, "UP\n");
-#endif
-		}
+			input_report_key(input_dev, BTN_TOUCH, 0);
+			input_report_abs(input_dev, ABS_PRESSURE, 0);
+			input_sync(input_dev);
 
-		/* measurement cycle ended */
-		if (!device_suspended(&ts->spi->dev)) {
-			ts->irq_disabled = 0;
-			enable_irq(ts->spi->irq);
+			if (!device_suspended(&ts->spi->dev)) {
+				ts->irq_disabled = 0;
+				enable_irq(ts->spi->irq);
+			}
+		} else {
+			/* pen is still down, continue with the measurement */
+			status = spi_async(ts->spi, &ts->msg[0]);
+			if (status)
+				dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
 		}
-		ts->pending = 0;
 	} else {
-		/* pen is still down, continue with the measurement */
-		ts->msg_idx = 0;
-		ts->wait_for_sync();
-		status = spi_async(ts->spi, &ts->msg[0]);
-		if (status)
-			dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
+		if (unlikely(ts->msg_idx && !ts->pendown)) {
+			/* measurement cycle ended */
+			if (!device_suspended(&ts->spi->dev)) {
+				ts->irq_disabled = 0;
+				enable_irq(ts->spi->irq);
+			}
+			ts->pending = 0;
+			ts->msg_idx = 0;
+		} else {
+			/* pen is still down, continue with the measurement */
+			ts->msg_idx = 0;
+			status = spi_async(ts->spi, &ts->msg[0]);
+			if (status)
+				dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
+		}
 	}
-
-	spin_unlock(&ts->lock);
-	return HRTIMER_NORESTART;
+	spin_unlock_irq(&ts->lock);
 }
 
 static irqreturn_t ads7846_irq(int irq, void *handle)
@@ -753,7 +687,8 @@ static irqreturn_t ads7846_irq(int irq, void *handle)
 	unsigned long flags;
 
 	spin_lock_irqsave(&ts->lock, flags);
-	if (likely(get_pendown_state(ts))) {
+
+	if (likely(ts->get_pendown_state())) {
 		if (!ts->irq_disabled) {
 			/* The ARM do_simple_IRQ() dispatcher doesn't act
 			 * like the other dispatchers:  it will report IRQs
@@ -763,8 +698,7 @@ static irqreturn_t ads7846_irq(int irq, void *handle)
 			ts->irq_disabled = 1;
 			disable_irq_nosync(ts->spi->irq);
 			ts->pending = 1;
-			hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
-					HRTIMER_MODE_REL);
+			mod_timer(&ts->timer, jiffies);
 		}
 	}
 	spin_unlock_irqrestore(&ts->lock, flags);
@@ -785,7 +719,7 @@ static void ads7846_disable(struct ads7846 *ts)
 	/* are we waiting for IRQ, or polling? */
 	if (!ts->pending) {
 		ts->irq_disabled = 1;
-		disable_irq(ts->spi->irq);
+		disable_irq_nosync(ts->spi->irq);
 	} else {
 		/* the timer will run at least once more, and
 		 * leave everything in a clean state, IRQ disabled
@@ -800,6 +734,7 @@ static void ads7846_disable(struct ads7846 *ts)
 	/* we know the chip's in lowpower mode since we always
 	 * leave it that way after every request
 	 */
+
 }
 
 /* Must be called with ts->lock held */
@@ -819,7 +754,7 @@ static int ads7846_suspend(struct spi_device *spi, pm_message_t message)
 
 	spin_lock_irq(&ts->lock);
 
-	ts->is_suspended = 1;
+	spi->dev.power.power_state = message;
 	ads7846_disable(ts);
 
 	spin_unlock_irq(&ts->lock);
@@ -834,7 +769,7 @@ static int ads7846_resume(struct spi_device *spi)
 
 	spin_lock_irq(&ts->lock);
 
-	ts->is_suspended = 0;
+	spi->dev.power.power_state = PMSG_ON;
 	ads7846_enable(ts);
 
 	spin_unlock_irq(&ts->lock);
@@ -842,45 +777,13 @@ static int ads7846_resume(struct spi_device *spi)
 	return 0;
 }
 
-static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts)
-{
-	struct ads7846_platform_data *pdata = spi->dev.platform_data;
-	int err;
-
-	/* REVISIT when the irq can be triggered active-low, or if for some
-	 * reason the touchscreen isn't hooked up, we don't need to access
-	 * the pendown state.
-	 */
-	if (!pdata->get_pendown_state && !gpio_is_valid(pdata->gpio_pendown)) {
-		dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
-		return -EINVAL;
-	}
-
-	if (pdata->get_pendown_state) {
-		ts->get_pendown_state = pdata->get_pendown_state;
-		return 0;
-	}
-
-	err = gpio_request(pdata->gpio_pendown, "ads7846_pendown");
-	if (err) {
-		dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
-				pdata->gpio_pendown);
-		return err;
-	}
-
-	ts->gpio_pendown = pdata->gpio_pendown;
-	return 0;
-}
-
 static int __devinit ads7846_probe(struct spi_device *spi)
 {
 	struct ads7846			*ts;
-	struct ads7846_packet		*packet;
 	struct input_dev		*input_dev;
 	struct ads7846_platform_data	*pdata = spi->dev.platform_data;
 	struct spi_message		*m;
 	struct spi_transfer		*x;
-	int				vref;
 	int				err;
 
 	if (!spi->irq) {
@@ -900,33 +803,46 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 		return -EINVAL;
 	}
 
+	/* REVISIT when the irq can be triggered active-low, or if for some
+	 * reason the touchscreen isn't hooked up, we don't need to access
+	 * the pendown state.
+	 */
+	if (pdata->get_pendown_state == NULL) {
+		dev_dbg(&spi->dev, "no get_pendown_state function?\n");
+		return -EINVAL;
+	}
+
 	/* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except
 	 * that even if the hardware can do that, the SPI controller driver
 	 * may not.  So we stick to very-portable 8 bit words, both RX and TX.
 	 */
 	spi->bits_per_word = 8;
-	spi->mode = SPI_MODE_0;
-	err = spi_setup(spi);
-	if (err < 0)
-		return err;
 
 	ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
-	packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
 	input_dev = input_allocate_device();
-	if (!ts || !packet || !input_dev) {
+	if (!ts || !input_dev) {
 		err = -ENOMEM;
 		goto err_free_mem;
 	}
 
 	dev_set_drvdata(&spi->dev, ts);
 
-	ts->packet = packet;
+	spi->dev.power.power_state = PMSG_ON;
+
 	ts->spi = spi;
 	ts->input = input_dev;
-	ts->vref_mv = pdata->vref_mv;
-	ts->swap_xy = pdata->swap_xy;
 
-	hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	ts->buflen = pdata->buflen ? : MAX_BUF_SAMPLE_LEN;
+	ts->buflen = ts->buflen & ~0x1;	/* must be even */
+
+	if (ads7843_setup_buffers(&spi->dev)) {
+		dev_dbg(&spi->dev, "error allocating memory for sample buffers\n");
+		err = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	init_timer(&ts->timer);
+	ts->timer.data = (unsigned long) ts;
 	ts->timer.function = ads7846_timer;
 
 	spin_lock_init(&ts->lock);
@@ -935,40 +851,22 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 	ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
 	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
 	ts->pressure_max = pdata->pressure_max ? : ~0;
+	ts->skip_samples = pdata->skip_samples ? : 0;
+	ts->rotate = pdata->rotate ? : 0;
 
-	if (pdata->filter != NULL) {
-		if (pdata->filter_init != NULL) {
-			err = pdata->filter_init(pdata, &ts->filter_data);
-			if (err < 0)
-				goto err_free_mem;
-		}
-		ts->filter = pdata->filter;
-		ts->filter_cleanup = pdata->filter_cleanup;
-	} else if (pdata->debounce_max) {
+	if (pdata->debounce_max) {
 		ts->debounce_max = pdata->debounce_max;
-		if (ts->debounce_max < 2)
-			ts->debounce_max = 2;
 		ts->debounce_tol = pdata->debounce_tol;
 		ts->debounce_rep = pdata->debounce_rep;
-		ts->filter = ads7846_debounce;
-		ts->filter_data = ts;
+		if (ts->debounce_rep > ts->debounce_max + 1)
+			ts->debounce_rep = ts->debounce_max - 1;
 	} else
-		ts->filter = ads7846_no_filter;
-
-	err = setup_pendown(spi, ts);
-	if (err)
-		goto err_cleanup_filter;
-
-	if (pdata->penirq_recheck_delay_usecs)
-		ts->penirq_recheck_delay_usecs =
-				pdata->penirq_recheck_delay_usecs;
-
-	ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
+		ts->debounce_tol = ~0;
+	ts->get_pendown_state = pdata->get_pendown_state;
 
 	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
-	snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model);
 
-	input_dev->name = ts->name;
+	input_dev->name = "ADS784x Touchscreen";
 	input_dev->phys = ts->phys;
 	input_dev->dev.parent = &spi->dev;
 
@@ -983,9 +881,8 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 			pdata->y_max ? : MAX_12BIT,
 			0, 0);
 	input_set_abs_params(input_dev, ABS_PRESSURE,
-			pdata->pressure_min, pdata->pressure_max, 0, 0);
-
-	vref = pdata->keep_vref_on;
+			pdata->pressure_min ? : 0,
+			pdata->pressure_max ? : 1, 0, 0);
 
 	/* set up the transfers to read touchscreen state; this assumes we
 	 * use formula #2 for pressure, not #3.
@@ -995,209 +892,176 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 
 	spi_message_init(m);
 
-	/* y- still on; turn on only y+ (and ADC) */
-	packet->read_y = READ_Y(vref);
-	x->tx_buf = &packet->read_y;
-	x->len = 1;
-	spi_message_add_tail(x, m);
-
-	x++;
-	x->rx_buf = &packet->tc.y;
-	x->len = 2;
-	spi_message_add_tail(x, m);
-
-	/* the first sample after switching drivers can be low quality;
-	 * optionally discard it, using a second one after the signals
-	 * have had enough time to stabilize.
-	 */
-	if (pdata->settle_delay_usecs) {
-		x->delay_usecs = pdata->settle_delay_usecs;
-
-		x++;
-		x->tx_buf = &packet->read_y;
-		x->len = 1;
+	if (ts->model == 7843) {
+		x->tx_buf = ts->txbuf;
+		x->rx_buf = ts->rxbuf;
+		x->len = ts->buflen * sizeof(u32) * 3; /* For every sample we take 3 samples and choose the better 2 */
 		spi_message_add_tail(x, m);
 
-		x++;
-		x->rx_buf = &packet->tc.y;
-		x->len = 2;
-		spi_message_add_tail(x, m);
-	}
-
-	m->complete = ads7846_rx_val;
-	m->context = ts;
-
-	m++;
-	spi_message_init(m);
-
-	/* turn y- off, x+ on, then leave in lowpower */
-	x++;
-	packet->read_x = READ_X(vref);
-	x->tx_buf = &packet->read_x;
-	x->len = 1;
-	spi_message_add_tail(x, m);
-
-	x++;
-	x->rx_buf = &packet->tc.x;
-	x->len = 2;
-	spi_message_add_tail(x, m);
-
-	/* ... maybe discard first sample ... */
-	if (pdata->settle_delay_usecs) {
-		x->delay_usecs = pdata->settle_delay_usecs;
+		m->complete = ads7843_rx_average;
+		m->context = ts;
 
-		x++;
-		x->tx_buf = &packet->read_x;
+		ts->last_msg = m;
+	} else {
+		/* y- still on; turn on only y+ (and ADC) */
+		ts->read_y = READ_Y;
+		x->tx_buf = &ts->read_y;
 		x->len = 1;
 		spi_message_add_tail(x, m);
 
 		x++;
-		x->rx_buf = &packet->tc.x;
+		x->rx_buf = &ts->tc.y;
 		x->len = 2;
 		spi_message_add_tail(x, m);
-	}
 
-	m->complete = ads7846_rx_val;
-	m->context = ts;
+		m->complete = ads7846_debounce;
+		m->context = ts;
 
-	/* turn y+ off, x- on; we'll use formula #2 */
-	if (ts->model == 7846) {
 		m++;
 		spi_message_init(m);
 
+		/* turn y- off, x+ on, then leave in lowpower */
 		x++;
-		packet->read_z1 = READ_Z1(vref);
-		x->tx_buf = &packet->read_z1;
+		ts->read_x = READ_X;
+		x->tx_buf = &ts->read_x;
 		x->len = 1;
 		spi_message_add_tail(x, m);
 
 		x++;
-		x->rx_buf = &packet->tc.z1;
+		x->rx_buf = &ts->tc.x;
 		x->len = 2;
 		spi_message_add_tail(x, m);
 
-		/* ... maybe discard first sample ... */
-		if (pdata->settle_delay_usecs) {
-			x->delay_usecs = pdata->settle_delay_usecs;
+		m->complete = ads7846_debounce;
+		m->context = ts;
+
+		/* turn y+ off, x- on; we'll use formula #2 */
+		if (ts->model == 7846) {
+			m++;
+			spi_message_init(m);
 
 			x++;
-			x->tx_buf = &packet->read_z1;
+			ts->read_z1 = READ_Z1;
+			x->tx_buf = &ts->read_z1;
 			x->len = 1;
 			spi_message_add_tail(x, m);
 
 			x++;
-			x->rx_buf = &packet->tc.z1;
+			x->rx_buf = &ts->tc.z1;
 			x->len = 2;
 			spi_message_add_tail(x, m);
-		}
-
-		m->complete = ads7846_rx_val;
-		m->context = ts;
-
-		m++;
-		spi_message_init(m);
 
-		x++;
-		packet->read_z2 = READ_Z2(vref);
-		x->tx_buf = &packet->read_z2;
-		x->len = 1;
-		spi_message_add_tail(x, m);
-
-		x++;
-		x->rx_buf = &packet->tc.z2;
-		x->len = 2;
-		spi_message_add_tail(x, m);
+			m->complete = ads7846_debounce;
+			m->context = ts;
 
-		/* ... maybe discard first sample ... */
-		if (pdata->settle_delay_usecs) {
-			x->delay_usecs = pdata->settle_delay_usecs;
+			m++;
+			spi_message_init(m);
 
 			x++;
-			x->tx_buf = &packet->read_z2;
+			ts->read_z2 = READ_Z2;
+			x->tx_buf = &ts->read_z2;
 			x->len = 1;
 			spi_message_add_tail(x, m);
 
 			x++;
-			x->rx_buf = &packet->tc.z2;
+			x->rx_buf = &ts->tc.z2;
 			x->len = 2;
 			spi_message_add_tail(x, m);
-		}
 
-		m->complete = ads7846_rx_val;
-		m->context = ts;
-	}
+			m->complete = ads7846_debounce;
+			m->context = ts;
+		}
 
-	/* power down */
-	m++;
-	spi_message_init(m);
+		/* power down */
+		m++;
+		spi_message_init(m);
 
-	x++;
-	packet->pwrdown = PWRDOWN;
-	x->tx_buf = &packet->pwrdown;
-	x->len = 1;
-	spi_message_add_tail(x, m);
+		x++;
+		ts->pwrdown = PWRDOWN;
+		x->tx_buf = &ts->pwrdown;
+		x->len = 1;
+		spi_message_add_tail(x, m);
 
-	x++;
-	x->rx_buf = &packet->dummy;
-	x->len = 2;
-	CS_CHANGE(*x);
-	spi_message_add_tail(x, m);
+		x++;
+		x->rx_buf = &ts->dummy;
+		x->len = 2;
+		CS_CHANGE(*x);
+		spi_message_add_tail(x, m);
 
-	m->complete = ads7846_rx;
-	m->context = ts;
+		m->complete = ads7846_rx;
+		m->context = ts;
 
-	ts->last_msg = m;
+		ts->last_msg = m;
+	}
 
 	if (request_irq(spi->irq, ads7846_irq, IRQF_TRIGGER_FALLING,
 			spi->dev.driver->name, ts)) {
-		dev_info(&spi->dev,
-			"trying pin change workaround on irq %d\n", spi->irq);
-		err = request_irq(spi->irq, ads7846_irq,
-				  IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
-				  spi->dev.driver->name, ts);
-		if (err) {
-			dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
-			goto err_free_gpio;
-		}
+		dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
+		err = -EBUSY;
+		goto err_free_buf;
 	}
 
-	err = ads784x_hwmon_register(spi, ts);
-	if (err)
-		goto err_free_irq;
-
 	dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
 
-	/* take a first sample, leaving nPENIRQ active and vREF off; avoid
+	/* take a first sample, leaving nPENIRQ active; avoid
 	 * the touchscreen, in case it's not connected.
 	 */
-	(void) ads7846_read12_ser(&spi->dev,
-			  READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
+	if (ts->model != 7843) {
+		/* take a first sample, leaving nPENIRQ active; avoid
+		 * the touchscreen, in case it's not connected.
+		 */
+		(void) ads7846_read12_ser(&spi->dev,
+				READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
+	}
 
-	err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
-	if (err)
-		goto err_remove_hwmon;
+	/* ads7843/7845 don't have temperature sensors, and
+	 * use the other sensors a bit differently too
+	 */
+	if (ts->model == 7846) {
+		device_create_file(&spi->dev, &dev_attr_temp0);
+		device_create_file(&spi->dev, &dev_attr_temp1);
+	}
+
+	if (ts->model != 7845 && ts->model != 7843)
+		device_create_file(&spi->dev, &dev_attr_vbatt);
+
+	if (ts->model != 7843) {
+		device_create_file(&spi->dev, &dev_attr_vaux);
+	}
+
+	device_create_file(&spi->dev, &dev_attr_pen_down);
+	device_create_file(&spi->dev, &dev_attr_disable);
 
 	err = input_register_device(input_dev);
 	if (err)
-		goto err_remove_attr_group;
+		goto err_remove_attr;
 
 	return 0;
 
- err_remove_attr_group:
-	sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
- err_remove_hwmon:
-	ads784x_hwmon_unregister(spi, ts);
- err_free_irq:
+ err_remove_attr:
+	device_remove_file(&spi->dev, &dev_attr_disable);
+	device_remove_file(&spi->dev, &dev_attr_pen_down);
+	if (ts->model == 7846) {
+		device_remove_file(&spi->dev, &dev_attr_temp1);
+		device_remove_file(&spi->dev, &dev_attr_temp0);
+	}
+
+	if (ts->model != 7845 && ts->model != 7843)
+		device_remove_file(&spi->dev, &dev_attr_vbatt);
+
+	if (ts->model != 7843) {
+		device_remove_file(&spi->dev, &dev_attr_vaux);
+	}
+
 	free_irq(spi->irq, ts);
- err_free_gpio:
-	if (ts->gpio_pendown != -1)
-		gpio_free(ts->gpio_pendown);
- err_cleanup_filter:
-	if (ts->filter_cleanup)
-		ts->filter_cleanup(ts->filter_data);
+
+ err_free_buf:
+	if (ts->txbuf)
+		kfree(ts->txbuf);
+	if (ts->rxbuf)
+		kfree(ts->rxbuf);
  err_free_mem:
 	input_free_device(input_dev);
-	kfree(packet);
 	kfree(ts);
 	return err;
 }
@@ -1206,24 +1070,33 @@ static int __devexit ads7846_remove(struct spi_device *spi)
 {
 	struct ads7846		*ts = dev_get_drvdata(&spi->dev);
 
-	ads784x_hwmon_unregister(spi, ts);
 	input_unregister_device(ts->input);
 
 	ads7846_suspend(spi, PMSG_SUSPEND);
 
-	sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
+	if (ts->txbuf)
+		kfree(ts->txbuf);
+	if (ts->rxbuf)
+		kfree(ts->rxbuf);
 
-	free_irq(ts->spi->irq, ts);
-	/* suspend left the IRQ disabled */
-	enable_irq(ts->spi->irq);
+	device_remove_file(&spi->dev, &dev_attr_disable);
+	device_remove_file(&spi->dev, &dev_attr_pen_down);
+	if (ts->model == 7846) {
+		device_remove_file(&spi->dev, &dev_attr_temp1);
+		device_remove_file(&spi->dev, &dev_attr_temp0);
+	}
+
+	if (ts->model != 7845 && ts->model != 7843)
+		device_remove_file(&spi->dev, &dev_attr_vbatt);
 
-	if (ts->gpio_pendown != -1)
-		gpio_free(ts->gpio_pendown);
+	if (ts->model != 7843) {
+		device_remove_file(&spi->dev, &dev_attr_vaux);
+	}
 
-	if (ts->filter_cleanup)
-		ts->filter_cleanup(ts->filter_data);
+	free_irq(ts->spi->irq, ts);
+	/* suspend left the IRQ disabled */
+	disable_irq_nosync(ts->spi->irq);
 
-	kfree(ts->packet);
 	kfree(ts);
 
 	dev_dbg(&spi->dev, "unregistered touchscreen\n");