1 files changed, 456 insertions, 430 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 16031933a8f6..14ea54b78e46 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -17,9 +17,11 @@
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  */
+#include <linux/types.h>
 #include <linux/hwmon.h>
 #include <linux/init.h>
 #include <linux/err.h>
+#include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
@@ -52,22 +54,23 @@
  * 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_DELAY   1       /* ms delay before the first sample */
+#define TS_POLL_PERIOD  5       /* ms delay between samples */
 
 /* this driver doesn't aim at the peak continuous sample rate */
 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
 
 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
+        /*
+         * For portability, we can't read 12 bit values using SPI (which
+         * would make the controller deliver them as native byte order u16
          * with msbs zeroed).  Instead, we read them as two 8-bit values,
          * *** WHICH NEED BYTESWAPPING *** and range adjustment.
          */
         u16     x;
         u16     y;
         u16     z1, z2;
-        int     ignore;
+        bool    ignore;
         u8      x_buf[3];
         u8      y_buf[3];
 };
@@ -110,8 +113,11 @@ struct ads7846 {
 
         struct spi_transfer     xfer[18];
         struct spi_message      msg[5];
-        struct spi_message      *last_msg;
-        int                     msg_idx;
+        int                     msg_count;
+        wait_queue_head_t       wait;
+
+        bool                    pendown;
+
         int                     read_cnt;
         int                     read_rep;
         int                     last_read;
@@ -122,14 +128,10 @@ struct ads7846 {
 
         u16                     penirq_recheck_delay_usecs;
 
-        spinlock_t              lock;
-        struct hrtimer          timer;
-        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;
+        struct mutex            lock;
+        bool                    stopped;        /* P: lock */
+        bool                    disabled;       /* P: lock */
+        bool                    suspended;      /* P: lock */
 
         int                     (*filter)(void *data, int data_idx, int *val);
         void                    *filter_data;
@@ -165,7 +167,7 @@ struct ads7846 {
 #define ADS_12_BIT              (0 << 3)
 #define ADS_SER                 (1 << 2)        /* non-differential */
 #define ADS_DFR                 (0 << 2)        /* differential */
-#define ADS_PD10_PDOWN          (0 << 0)        /* lowpower mode + penirq */
+#define ADS_PD10_PDOWN          (0 << 0)        /* low power mode + penirq */
 #define ADS_PD10_ADC_ON         (1 << 0)        /* ADC on */
 #define ADS_PD10_REF_ON         (2 << 0)        /* vREF on + penirq */
 #define ADS_PD10_ALL_ON         (3 << 0)        /* ADC + vREF on */
@@ -193,6 +195,78 @@ struct ads7846 {
 #define REF_ON  (READ_12BIT_DFR(x, 1, 1))
 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
 
+/* Must be called with ts->lock held */
+static void ads7846_stop(struct ads7846 *ts)
+{
+        if (!ts->disabled && !ts->suspended) {
+                /* Signal IRQ thread to stop polling and disable the handler. */
+                ts->stopped = true;
+                mb();
+                wake_up(&ts->wait);
+                disable_irq(ts->spi->irq);
+        }
+}
+
+/* Must be called with ts->lock held */
+static void ads7846_restart(struct ads7846 *ts)
+{
+        if (!ts->disabled && !ts->suspended) {
+                /* Tell IRQ thread that it may poll the device. */
+                ts->stopped = false;
+                mb();
+                enable_irq(ts->spi->irq);
+        }
+}
+
+/* Must be called with ts->lock held */
+static void __ads7846_disable(struct ads7846 *ts)
+{
+        ads7846_stop(ts);
+        regulator_disable(ts->reg);
+
+        /*
+         * We know the chip's in low power mode since we always
+         * leave it that way after every request
+         */
+}
+
+/* Must be called with ts->lock held */
+static void __ads7846_enable(struct ads7846 *ts)
+{
+        regulator_enable(ts->reg);
+        ads7846_restart(ts);
+}
+
+static void ads7846_disable(struct ads7846 *ts)
+{
+        mutex_lock(&ts->lock);
+
+        if (!ts->disabled) {
+
+                if  (!ts->suspended)
+                        __ads7846_disable(ts);
+
+                ts->disabled = true;
+        }
+
+        mutex_unlock(&ts->lock);
+}
+
+static void ads7846_enable(struct ads7846 *ts)
+{
+        mutex_lock(&ts->lock);
+
+        if (ts->disabled) {
+
+                ts->disabled = false;
+
+                if (!ts->suspended)
+                        __ads7846_enable(ts);
+        }
+
+        mutex_unlock(&ts->lock);
+}
+
 /*--------------------------------------------------------------------------*/
 
 /*
@@ -219,23 +293,15 @@ struct ads7845_ser_req {
         struct spi_transfer     xfer[2];
 };
 
-static void ads7846_enable(struct ads7846 *ts);
-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;
-}
-
 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;
+        struct spi_device *spi = to_spi_device(dev);
+        struct ads7846 *ts = dev_get_drvdata(dev);
+        struct ser_req *req;
+        int status;
+        int use_internal;
 
+        req = kzalloc(sizeof *req, GFP_KERNEL);
         if (!req)
                 return -ENOMEM;
 
@@ -282,11 +348,11 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
         CS_CHANGE(req->xfer[5]);
         spi_message_add_tail(&req->xfer[5], &req->msg);
 
-        ts->irq_disabled = 1;
-        disable_irq(spi->irq);
+        mutex_lock(&ts->lock);
+        ads7846_stop(ts);
         status = spi_sync(spi, &req->msg);
-        ts->irq_disabled = 0;
-        enable_irq(spi->irq);
+        ads7846_restart(ts);
+        mutex_unlock(&ts->lock);
 
         if (status == 0) {
                 /* on-wire is a must-ignore bit, a BE12 value, then padding */
@@ -301,11 +367,12 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
 
 static int ads7845_read12_ser(struct device *dev, unsigned command)
 {
-        struct spi_device       *spi = to_spi_device(dev);
-        struct ads7846          *ts = dev_get_drvdata(dev);
-        struct ads7845_ser_req  *req = kzalloc(sizeof *req, GFP_KERNEL);
-        int                     status;
+        struct spi_device *spi = to_spi_device(dev);
+        struct ads7846 *ts = dev_get_drvdata(dev);
+        struct ads7845_ser_req *req;
+        int status;
 
+        req = kzalloc(sizeof *req, GFP_KERNEL);
         if (!req)
                 return -ENOMEM;
 
@@ -317,11 +384,11 @@ static int ads7845_read12_ser(struct device *dev, unsigned command)
         req->xfer[0].len = 3;
         spi_message_add_tail(&req->xfer[0], &req->msg);
 
-        ts->irq_disabled = 1;
-        disable_irq(spi->irq);
+        mutex_lock(&ts->lock);
+        ads7846_stop(ts);
         status = spi_sync(spi, &req->msg);
-        ts->irq_disabled = 0;
-        enable_irq(spi->irq);
+        ads7846_restart(ts);
+        mutex_unlock(&ts->lock);
 
         if (status == 0) {
                 /* BE12 value, then padding */
@@ -374,6 +441,7 @@ static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
         /* external resistors may scale vAUX into 0..vREF */
         retval *= ts->vref_mv;
         retval = retval >> 12;
+
         return retval;
 }
 
@@ -384,13 +452,13 @@ static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t 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,
@@ -498,17 +566,12 @@ static inline void ads784x_hwmon_unregister(struct spi_device *spi,
 }
 #endif
 
-static int is_pen_down(struct device *dev)
-{
-        struct ads7846  *ts = dev_get_drvdata(dev);
-
-        return ts->pendown;
-}
-
 static ssize_t ads7846_pen_down_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
 {
-        return sprintf(buf, "%u\n", is_pen_down(dev));
+        struct ads7846 *ts = dev_get_drvdata(dev);
+
+        return sprintf(buf, "%u\n", ts->pendown);
 }
 
 static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
@@ -516,7 +579,7 @@ static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
 static ssize_t ads7846_disable_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
 {
-        struct ads7846  *ts = dev_get_drvdata(dev);
+        struct ads7846 *ts = dev_get_drvdata(dev);
 
         return sprintf(buf, "%u\n", ts->disabled);
 }
@@ -531,15 +594,11 @@ static ssize_t ads7846_disable_store(struct device *dev,
         if (strict_strtoul(buf, 10, &i))
                 return -EINVAL;
 
-        spin_lock_irq(&ts->lock);
-
         if (i)
                 ads7846_disable(ts);
         else
                 ads7846_enable(ts);
 
-        spin_unlock_irq(&ts->lock);
-
         return count;
 }
 
@@ -569,23 +628,141 @@ static void null_wait_for_sync(void)
 {
 }
 
-/*
- * PENIRQ only kicks the timer.  The timer only reissues the SPI transfer,
- * to retrieve touchscreen status.
- *
- * The SPI transfer completion callback does the real work.  It reports
- * touchscreen events and reactivates the timer (or IRQ) as appropriate.
- */
+static int ads7846_debounce_filter(void *ads, int data_idx, int *val)
+{
+        struct ads7846 *ts = ads;
+
+        if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
+                /* Start over collecting consistent readings. */
+                ts->read_rep = 0;
+                /*
+                 * 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->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->read_cnt = 0;
+                        return ADS7846_FILTER_IGNORE;
+                }
+        } else {
+                if (++ts->read_rep > ts->debounce_rep) {
+                        /*
+                         * Got a good reading for this coordinate,
+                         * go for the next one.
+                         */
+                        ts->read_cnt = 0;
+                        ts->read_rep = 0;
+                        return ADS7846_FILTER_OK;
+                } 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 int ads7846_get_value(struct ads7846 *ts, struct spi_message *m)
+{
+        struct spi_transfer *t =
+                list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
+
+        if (ts->model == 7845) {
+                return be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3;
+        } else {
+                /*
+                 * adjust:  on-wire is a must-ignore bit, a BE12 value, then
+                 * padding; built from two 8 bit values written msb-first.
+                 */
+                return be16_to_cpup((__be16 *)t->rx_buf) >> 3;
+        }
+}
+
+static void ads7846_update_value(struct spi_message *m, int val)
+{
+        struct spi_transfer *t =
+                list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
+
+        *(u16 *)t->rx_buf = val;
+}
+
+static void ads7846_read_state(struct ads7846 *ts)
+{
+        struct ads7846_packet *packet = ts->packet;
+        struct spi_message *m;
+        int msg_idx = 0;
+        int val;
+        int action;
+        int error;
+
+        while (msg_idx < ts->msg_count) {
+
+                ts->wait_for_sync();
+
+                m = &ts->msg[msg_idx];
+                error = spi_sync(ts->spi, m);
+                if (error) {
+                        dev_err(&ts->spi->dev, "spi_async --> %d\n", error);
+                        packet->tc.ignore = true;
+                        return;
+                }
+
+                /*
+                 * Last message is power down request, no need to convert
+                 * or filter the value.
+                 */
+                if (msg_idx < ts->msg_count - 1) {
 
-static void ads7846_rx(void *ads)
+                        val = ads7846_get_value(ts, m);
+
+                        action = ts->filter(ts->filter_data, msg_idx, &val);
+                        switch (action) {
+                        case ADS7846_FILTER_REPEAT:
+                                continue;
+
+                        case ADS7846_FILTER_IGNORE:
+                                packet->tc.ignore = true;
+                                msg_idx = ts->msg_count - 1;
+                                continue;
+
+                        case ADS7846_FILTER_OK:
+                                ads7846_update_value(m, val);
+                                packet->tc.ignore = false;
+                                msg_idx++;
+                                break;
+
+                        default:
+                                BUG();
+                        }
+                } else {
+                        msg_idx++;
+                }
+        }
+}
+
+static void ads7846_report_state(struct ads7846 *ts)
 {
-        struct ads7846          *ts = ads;
-        struct ads7846_packet   *packet = ts->packet;
-        unsigned                Rt;
-        u16                     x, y, z1, z2;
+        struct ads7846_packet *packet = ts->packet;
+        unsigned int Rt;
+        u16 x, y, z1, z2;
 
-        /* ads7846_rx_val() did in-place conversion (including byteswap) from
-         * on-the-wire format as part of debouncing to get stable readings.
+        /*
+         * ads7846_get_value() does in-place conversion (including byte swap)
+         * from on-the-wire format as part of debouncing to get stable
+         * readings.
          */
         if (ts->model == 7845) {
                 x = *(u16 *)packet->tc.x_buf;
@@ -623,19 +800,19 @@ static void ads7846_rx(void *ads)
                 Rt = 0;
         }
 
-        /* Sample found inconsistent by debouncing or pressure is beyond
+        /*
+         * 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) {
                 dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n",
                          packet->tc.ignore, Rt);
-                hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
-                              HRTIMER_MODE_REL);
                 return;
         }
 
-        /* Maybe check the pendown state before reporting. This discards
+        /*
+         * Maybe check the pendown state before reporting. This discards
          * false readings when the pen is lifted.
          */
         if (ts->penirq_recheck_delay_usecs) {
@@ -644,8 +821,9 @@ static void ads7846_rx(void *ads)
                         Rt = 0;
         }
 
-        /* NOTE: We can't rely on the pressure to determine the pen down
-         * state, even this controller has a pressure sensor.  The pressure
+        /*
+         * 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.
          *
@@ -655,15 +833,15 @@ static void ads7846_rx(void *ads)
         if (Rt) {
                 struct input_dev *input = ts->input;
 
+                if (ts->swap_xy)
+                        swap(x, y);
+
                 if (!ts->pendown) {
                         input_report_key(input, BTN_TOUCH, 1);
-                        ts->pendown = 1;
+                        ts->pendown = true;
                         dev_vdbg(&ts->spi->dev, "DOWN\n");
                 }
 
-                if (ts->swap_xy)
-                        swap(x, y);
-
                 input_report_abs(input, ABS_X, x);
                 input_report_abs(input, ABS_Y, y);
                 input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt);
@@ -671,246 +849,94 @@ static void ads7846_rx(void *ads)
                 input_sync(input);
                 dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
         }
-
-        hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
-                        HRTIMER_MODE_REL);
-}
-
-static int ads7846_debounce(void *ads, int data_idx, int *val)
-{
-        struct ads7846          *ts = ads;
-
-        if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
-                /* Start over collecting consistent readings. */
-                ts->read_rep = 0;
-                /* 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->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->read_cnt = 0;
-                        return ADS7846_FILTER_IGNORE;
-                }
-        } else {
-                if (++ts->read_rep > ts->debounce_rep) {
-                        /* Got a good reading for this coordinate,
-                         * go for the next one. */
-                        ts->read_cnt = 0;
-                        ts->read_rep = 0;
-                        return ADS7846_FILTER_OK;
-                } 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)
+static irqreturn_t ads7846_hard_irq(int irq, void *handle)
 {
-        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);
-
-        if (ts->model == 7845) {
-                val = be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3;
-        } else {
-                /* 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;
-        }
+        struct ads7846 *ts = handle;
 
-        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);
+        return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 }
 
-static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
-{
-        struct ads7846  *ts = container_of(handle, struct ads7846, timer);
-        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);
-
-                        ts->pendown = 0;
-                        dev_vdbg(&ts->spi->dev, "UP\n");
-                }
-
-                /* measurement cycle ended */
-                if (!device_suspended(&ts->spi->dev)) {
-                        ts->irq_disabled = 0;
-                        enable_irq(ts->spi->irq);
-                }
-                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);
-        }
-
-        spin_unlock(&ts->lock);
-        return HRTIMER_NORESTART;
-}
 
 static irqreturn_t ads7846_irq(int irq, void *handle)
 {
         struct ads7846 *ts = handle;
-        unsigned long flags;
-
-        spin_lock_irqsave(&ts->lock, flags);
-        if (likely(get_pendown_state(ts))) {
-                if (!ts->irq_disabled) {
-                        /* The ARM do_simple_IRQ() dispatcher doesn't act
-                         * like the other dispatchers:  it will report IRQs
-                         * even after they've been disabled.  We work around
-                         * that here.  (The "generic irq" framework may help...)
-                         */
-                        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);
-                }
-        }
-        spin_unlock_irqrestore(&ts->lock, flags);
 
-        return IRQ_HANDLED;
-}
+        /* Start with a small delay before checking pendown state */
+        msleep(TS_POLL_DELAY);
 
-/*--------------------------------------------------------------------------*/
+        while (!ts->stopped && get_pendown_state(ts)) {
 
-/* Must be called with ts->lock held */
-static void ads7846_disable(struct ads7846 *ts)
-{
-        if (ts->disabled)
-                return;
+                /* pen is down, continue with the measurement */
+                ads7846_read_state(ts);
 
-        ts->disabled = 1;
+                if (!ts->stopped)
+                        ads7846_report_state(ts);
 
-        /* are we waiting for IRQ, or polling? */
-        if (!ts->pending) {
-                ts->irq_disabled = 1;
-                disable_irq(ts->spi->irq);
-        } else {
-                /* the timer will run at least once more, and
-                 * leave everything in a clean state, IRQ disabled
-                 */
-                while (ts->pending) {
-                        spin_unlock_irq(&ts->lock);
-                        msleep(1);
-                        spin_lock_irq(&ts->lock);
-                }
+                wait_event_timeout(ts->wait, ts->stopped,
+                                   msecs_to_jiffies(TS_POLL_PERIOD));
         }
 
-        regulator_disable(ts->reg);
-
-        /* we know the chip's in lowpower mode since we always
-         * leave it that way after every request
-         */
-}
+        if (ts->pendown) {
+                struct input_dev *input = ts->input;
 
-/* Must be called with ts->lock held */
-static void ads7846_enable(struct ads7846 *ts)
-{
-        if (!ts->disabled)
-                return;
+                input_report_key(input, BTN_TOUCH, 0);
+                input_report_abs(input, ABS_PRESSURE, 0);
+                input_sync(input);
 
-        regulator_enable(ts->reg);
+                ts->pendown = false;
+                dev_vdbg(&ts->spi->dev, "UP\n");
+        }
 
-        ts->disabled = 0;
-        ts->irq_disabled = 0;
-        enable_irq(ts->spi->irq);
+        return IRQ_HANDLED;
 }
 
 static int ads7846_suspend(struct spi_device *spi, pm_message_t message)
 {
         struct ads7846 *ts = dev_get_drvdata(&spi->dev);
 
-        spin_lock_irq(&ts->lock);
+        mutex_lock(&ts->lock);
 
-        ts->is_suspended = 1;
-        ads7846_disable(ts);
+        if (!ts->suspended) {
 
-        spin_unlock_irq(&ts->lock);
+                if (!ts->disabled)
+                        __ads7846_disable(ts);
 
-        if (device_may_wakeup(&ts->spi->dev))
-                enable_irq_wake(ts->spi->irq);
+                if (device_may_wakeup(&ts->spi->dev))
+                        enable_irq_wake(ts->spi->irq);
 
-        return 0;
+                ts->suspended = true;
+        }
+
+        mutex_unlock(&ts->lock);
 
+        return 0;
 }
 
 static int ads7846_resume(struct spi_device *spi)
 {
         struct ads7846 *ts = dev_get_drvdata(&spi->dev);
 
-        if (device_may_wakeup(&ts->spi->dev))
-                disable_irq_wake(ts->spi->irq);
+        mutex_lock(&ts->lock);
+
+        if (ts->suspended) {
 
-        spin_lock_irq(&ts->lock);
+                ts->suspended = false;
 
-        ts->is_suspended = 0;
-        ads7846_enable(ts);
+                if (device_may_wakeup(&ts->spi->dev))
+                        disable_irq_wake(ts->spi->irq);
 
-        spin_unlock_irq(&ts->lock);
+                if (!ts->disabled)
+                        __ads7846_enable(ts);
+        }
+
+        mutex_unlock(&ts->lock);
 
         return 0;
 }
 
-static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts)
+static int __devinit ads7846_setup_pendown(struct spi_device *spi, struct ads7846 *ts)
 {
         struct ads7846_platform_data *pdata = spi->dev.platform_data;
         int err;
@@ -932,146 +958,40 @@ static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts)
         err = gpio_request(pdata->gpio_pendown, "ads7846_pendown");
         if (err) {
                 dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
-                                pdata->gpio_pendown);
+                        pdata->gpio_pendown);
                 return err;
         }
 
         ts->gpio_pendown = pdata->gpio_pendown;
+
         return 0;
 }
 
-static int __devinit ads7846_probe(struct spi_device *spi)
+/*
+ * Set up the transfers to read touchscreen state; this assumes we
+ * use formula #2 for pressure, not #3.
+ */
+static void __devinit ads7846_setup_spi_msg(struct ads7846 *ts,
+                                const struct ads7846_platform_data *pdata)
 {
-        struct ads7846 *ts;
-        struct ads7846_packet *packet;
-        struct input_dev *input_dev;
-        const struct ads7846_platform_data *pdata = spi->dev.platform_data;
-        struct spi_message *m;
-        struct spi_transfer *x;
-        unsigned long irq_flags;
-        int vref;
-        int err;
-
-        if (!spi->irq) {
-                dev_dbg(&spi->dev, "no IRQ?\n");
-                return -ENODEV;
-        }
-
-        if (!pdata) {
-                dev_dbg(&spi->dev, "no platform data?\n");
-                return -ENODEV;
-        }
-
-        /* don't exceed max specified sample rate */
-        if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
-                dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
-                                (spi->max_speed_hz/SAMPLE_BITS)/1000);
-                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) {
-                err = -ENOMEM;
-                goto err_free_mem;
-        }
-
-        dev_set_drvdata(&spi->dev, ts);
-
-        ts->packet = packet;
-        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->timer.function = ads7846_timer;
-
-        spin_lock_init(&ts->lock);
-
-        ts->model = pdata->model ? : 7846;
-        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;
-
-        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) {
-                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;
-        } 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;
-
-        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->phys = ts->phys;
-        input_dev->dev.parent = &spi->dev;
-
-        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
-        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
-        input_set_abs_params(input_dev, ABS_X,
-                        pdata->x_min ? : 0,
-                        pdata->x_max ? : MAX_12BIT,
-                        0, 0);
-        input_set_abs_params(input_dev, ABS_Y,
-                        pdata->y_min ? : 0,
-                        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;
+        struct spi_message *m = &ts->msg[0];
+        struct spi_transfer *x = ts->xfer;
+        struct ads7846_packet *packet = ts->packet;
+        int vref = pdata->keep_vref_on;
 
         if (ts->model == 7873) {
-                /* The AD7873 is almost identical to the ADS7846
+                /*
+                 * The AD7873 is almost identical to the ADS7846
                  * keep VREF off during differential/ratiometric
-                 * conversion modes
+                 * conversion modes.
                  */
                 ts->model = 7846;
                 vref = 0;
         }
 
-        /* set up the transfers to read touchscreen state; this assumes we
-         * use formula #2 for pressure, not #3.
-         */
-        m = &ts->msg[0];
-        x = ts->xfer;
-
+        ts->msg_count = 1;
         spi_message_init(m);
+        m->context = ts;
 
         if (ts->model == 7845) {
                 packet->read_y_cmd[0] = READ_Y(vref);
@@ -1094,7 +1014,8 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 spi_message_add_tail(x, m);
         }
 
-        /* the first sample after switching drivers can be low quality;
+        /*
+         * 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.
          */
@@ -1112,11 +1033,10 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 spi_message_add_tail(x, m);
         }
 
-        m->complete = ads7846_rx_val;
-        m->context = ts;
-
+        ts->msg_count++;
         m++;
         spi_message_init(m);
+        m->context = ts;
 
         if (ts->model == 7845) {
                 x++;
@@ -1156,13 +1076,12 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 spi_message_add_tail(x, m);
         }
 
-        m->complete = ads7846_rx_val;
-        m->context = ts;
-
         /* turn y+ off, x- on; we'll use formula #2 */
         if (ts->model == 7846) {
+                ts->msg_count++;
                 m++;
                 spi_message_init(m);
+                m->context = ts;
 
                 x++;
                 packet->read_z1 = READ_Z1(vref);
@@ -1190,11 +1109,10 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                         spi_message_add_tail(x, m);
                 }
 
-                m->complete = ads7846_rx_val;
-                m->context = ts;
-
+                ts->msg_count++;
                 m++;
                 spi_message_init(m);
+                m->context = ts;
 
                 x++;
                 packet->read_z2 = READ_Z2(vref);
@@ -1221,14 +1139,13 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                         x->len = 2;
                         spi_message_add_tail(x, m);
                 }
-
-                m->complete = ads7846_rx_val;
-                m->context = ts;
         }
 
         /* power down */
+        ts->msg_count++;
         m++;
         spi_message_init(m);
+        m->context = ts;
 
         if (ts->model == 7845) {
                 x++;
@@ -1251,11 +1168,119 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 
         CS_CHANGE(*x);
         spi_message_add_tail(x, m);
+}
 
-        m->complete = ads7846_rx;
-        m->context = ts;
+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;
+        unsigned long irq_flags;
+        int err;
+
+        if (!spi->irq) {
+                dev_dbg(&spi->dev, "no IRQ?\n");
+                return -ENODEV;
+        }
+
+        if (!pdata) {
+                dev_dbg(&spi->dev, "no platform data?\n");
+                return -ENODEV;
+        }
+
+        /* don't exceed max specified sample rate */
+        if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
+                dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
+                                (spi->max_speed_hz/SAMPLE_BITS)/1000);
+                return -EINVAL;
+        }
+
+        /* We'd set TX word size 8 bits and RX word size 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->last_msg = m;
+        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) {
+                err = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        dev_set_drvdata(&spi->dev, ts);
+
+        ts->packet = packet;
+        ts->spi = spi;
+        ts->input = input_dev;
+        ts->vref_mv = pdata->vref_mv;
+        ts->swap_xy = pdata->swap_xy;
+
+        mutex_init(&ts->lock);
+        init_waitqueue_head(&ts->wait);
+
+        ts->model = pdata->model ? : 7846;
+        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;
+
+        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) {
+                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_filter;
+                ts->filter_data = ts;
+        } else {
+                ts->filter = ads7846_no_filter;
+        }
+
+        err = ads7846_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;
+
+        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->phys = ts->phys;
+        input_dev->dev.parent = &spi->dev;
+
+        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+        input_set_abs_params(input_dev, ABS_X,
+                        pdata->x_min ? : 0,
+                        pdata->x_max ? : MAX_12BIT,
+                        0, 0);
+        input_set_abs_params(input_dev, ABS_Y,
+                        pdata->y_min ? : 0,
+                        pdata->y_max ? : MAX_12BIT,
+                        0, 0);
+        input_set_abs_params(input_dev, ABS_PRESSURE,
+                        pdata->pressure_min, pdata->pressure_max, 0, 0);
+
+        ads7846_setup_spi_msg(ts, pdata);
 
         ts->reg = regulator_get(&spi->dev, "vcc");
         if (IS_ERR(ts->reg)) {
@@ -1271,16 +1296,17 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         }
 
         irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
+        irq_flags |= IRQF_ONESHOT;
 
-        err = request_irq(spi->irq, ads7846_irq, irq_flags,
-                          spi->dev.driver->name, ts);
-
+        err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
+                                   irq_flags, spi->dev.driver->name, ts);
         if (err && !pdata->irq_flags) {
                 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);
+                irq_flags |= IRQF_TRIGGER_RISING;
+                err = request_threaded_irq(spi->irq,
+                                  ads7846_hard_irq, ads7846_irq,
+                                  irq_flags, spi->dev.driver->name, ts);
         }
 
         if (err) {
@@ -1294,7 +1320,8 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 
         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 and vREF off; avoid
          * the touchscreen, in case it's not connected.
          */
         if (ts->model == 7845)
@@ -1340,20 +1367,18 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 
 static int __devexit ads7846_remove(struct spi_device *spi)
 {
-        struct ads7846          *ts = dev_get_drvdata(&spi->dev);
+        struct ads7846 *ts = dev_get_drvdata(&spi->dev);
 
         device_init_wakeup(&spi->dev, false);
 
-        ads784x_hwmon_unregister(spi, ts);
-        input_unregister_device(ts->input);
-
-        ads7846_suspend(spi, PMSG_SUSPEND);
-
         sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
 
+        ads7846_disable(ts);
         free_irq(ts->spi->irq, ts);
-        /* suspend left the IRQ disabled */
-        enable_irq(ts->spi->irq);
+
+        input_unregister_device(ts->input);
+
+        ads784x_hwmon_unregister(spi, ts);
 
         regulator_disable(ts->reg);
         regulator_put(ts->reg);
@@ -1368,6 +1393,7 @@ static int __devexit ads7846_remove(struct spi_device *spi)
         kfree(ts);
 
         dev_dbg(&spi->dev, "unregistered touchscreen\n");
+
         return 0;
 }