1 files changed, 389 insertions, 192 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index c6164b6f476a..cd251efda410 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -17,8 +17,9 @@
  *  it under the terms of the GNU General Public License version 2 as
  *  published by the Free Software Foundation.
  */
-#include <linux/device.h>
+#include <linux/hwmon.h>
 #include <linux/init.h>
+#include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
@@ -54,7 +55,8 @@
  * files.
  */
 
-#define TS_POLL_PERIOD  msecs_to_jiffies(10)
+#define TS_POLL_DELAY   (1 * 1000000)   /* ns delay before the first sample */
+#define TS_POLL_PERIOD  (5 * 1000000)   /* ns delay between samples */
 
 /* this driver doesn't aim at the peak continuous sample rate */
 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
@@ -63,12 +65,12 @@ 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 then range adjustment.
+         * *** WHICH NEED BYTESWAPPING *** and range adjustment.
          */
-        __be16 x;
-        __be16 y;
-        __be16 z1, z2;
-        int    ignore;
+        u16     x;
+        u16     y;
+        u16     z1, z2;
+        int     ignore;
 };
 
 struct ads7846 {
@@ -76,7 +78,12 @@ struct ads7846 {
         char                    phys[32];
 
         struct spi_device       *spi;
+
+#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
         struct attribute_group  *attr_group;
+        struct class_device     *hwmon;
+#endif
+
         u16                     model;
         u16                     vref_delay_usecs;
         u16                     x_plate_ohms;
@@ -99,13 +106,16 @@ struct ads7846 {
         u16                     debounce_rep;
 
         spinlock_t              lock;
-        struct timer_list       timer;          /* P: 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;
 
+        int                     (*filter)(void *data, int data_idx, int *val);
+        void                    *filter_data;
+        void                    (*filter_cleanup)(void *data);
         int                     (*get_pendown_state)(void);
 };
 
@@ -142,15 +152,16 @@ struct ads7846 {
 #define MAX_12BIT       ((1<<12)-1)
 
 /* leave ADC powered up (disables penirq) between differential samples */
-#define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
-        | ADS_12_BIT | ADS_DFR)
+#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_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 */
 
 /* single-ended samples need to first power up reference voltage;
  * we leave both ADC and VREF powered
@@ -158,14 +169,19 @@ struct ads7846 {
 #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
         | ADS_12_BIT | ADS_SER)
 
-#define REF_ON  (READ_12BIT_DFR(x) | ADS_PD10_ALL_ON)
-#define REF_OFF (READ_12BIT_DFR(y) | ADS_PD10_PDOWN)
+#define REF_ON  (READ_12BIT_DFR(x, 1, 1))
+#define REF_OFF (READ_12BIT_DFR(y, 0, 0))
 
 /*--------------------------------------------------------------------------*/
 
 /*
  * 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.
  */
+static unsigned vREF_mV;
+module_param(vREF_mV, uint, 0);
+MODULE_PARM_DESC(vREF_mV, "external vREF voltage, in milliVolts");
 
 struct ser_req {
         u8                      ref_on;
@@ -193,50 +209,55 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
         struct ser_req          *req = kzalloc(sizeof *req, GFP_KERNEL);
         int                     status;
         int                     sample;
-        int                     i;
+        int                     use_internal;
 
         if (!req)
                 return -ENOMEM;
 
         spi_message_init(&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].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;
+        /* 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);
+        }
 
         /* 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].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 ... */
 
-        /* turn off reference */
-        req->ref_off = REF_OFF;
-        req->xfer[4].tx_buf = &req->ref_off;
-        req->xfer[4].len = 1;
-        req->xfer[5].rx_buf = &req->scratch;
-        req->xfer[5].len = 2;
-
-        CS_CHANGE(req->xfer[5]);
-
-        /* 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);
+        /* maybe off internal vREF */
+        if (use_internal) {
+                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);
+
+                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);
+        }
 
         ts->irq_disabled = 1;
         disable_irq(spi->irq);
@@ -256,25 +277,173 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
         return status ? status : sample;
 }
 
-#define SHOW(name) static ssize_t \
+#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
+
+#define SHOW(name, var, adjust) 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(name) | ADS_PD10_ALL_ON); \
+                        READ_12BIT_SER(var) | ADS_PD10_ALL_ON); \
         if (v < 0) \
                 return v; \
-        return sprintf(buf, "%u\n", (unsigned) v); \
+        return sprintf(buf, "%u\n", adjust(ts, v)); \
 } \
 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 
-SHOW(temp0)
-SHOW(temp1)
-SHOW(vaux)
-SHOW(vbatt)
+
+/* Sysfs conventions report temperatures in millidegrees Celcius.
+ * 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 *= 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 class_device *hwmon;
+        int err;
+
+        /* hwmon sensors need a reference voltage */
+        switch (ts->model) {
+        case 7846:
+                if (!vREF_mV) {
+                        dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
+                        vREF_mV = 2500;
+                }
+                break;
+        case 7845:
+        case 7843:
+                if (!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
 
 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;
 }
@@ -318,46 +487,14 @@ static ssize_t ads7846_disable_store(struct device *dev,
 
 static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
 
-static struct attribute *ads7846_attributes[] = {
-        &dev_attr_temp0.attr,
-        &dev_attr_temp1.attr,
-        &dev_attr_vbatt.attr,
-        &dev_attr_vaux.attr,
-        &dev_attr_pen_down.attr,
-        &dev_attr_disable.attr,
-        NULL,
-};
-
-static struct attribute_group ads7846_attr_group = {
-        .attrs = ads7846_attributes,
-};
-
-/*
- * ads7843/7845 don't have temperature sensors, and
- * use the other sensors a bit differently too
- */
-
-static struct attribute *ads7843_attributes[] = {
-        &dev_attr_vbatt.attr,
-        &dev_attr_vaux.attr,
+static struct attribute *ads784x_attributes[] = {
         &dev_attr_pen_down.attr,
         &dev_attr_disable.attr,
         NULL,
 };
 
-static struct attribute_group ads7843_attr_group = {
-        .attrs = ads7843_attributes,
-};
-
-static struct attribute *ads7845_attributes[] = {
-        &dev_attr_vaux.attr,
-        &dev_attr_pen_down.attr,
-        &dev_attr_disable.attr,
-        NULL,
-};
-
-static struct attribute_group ads7845_attr_group = {
-        .attrs = ads7845_attributes,
+static struct attribute_group ads784x_attr_group = {
+        .attrs = ads784x_attributes,
 };
 
 /*--------------------------------------------------------------------------*/
@@ -373,25 +510,22 @@ static struct attribute_group ads7845_attr_group = {
 static void ads7846_rx(void *ads)
 {
         struct ads7846          *ts = ads;
-        struct input_dev        *input_dev = ts->input;
         unsigned                Rt;
-        unsigned                sync = 0;
         u16                     x, y, z1, z2;
-        unsigned long           flags;
 
-        /* adjust:  on-wire is a must-ignore bit, a BE12 value, then padding;
-         * built from two 8 bit values written msb-first.
+        /* ads7846_rx_val() did in-place conversion (including byteswap) from
+         * on-the-wire format as part of debouncing to get stable readings.
          */
-        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;
+        x = ts->tc.x;
+        y = ts->tc.y;
+        z1 = ts->tc.z1;
+        z2 = ts->tc.z2;
 
         /* range filtering */
         if (x == MAX_12BIT)
                 x = 0;
 
-        if (likely(x && z1 && !device_suspended(&ts->spi->dev))) {
+        if (likely(x && z1)) {
                 /* compute touch pressure resistance using equation #2 */
                 Rt = z2;
                 Rt -= z1;
@@ -403,100 +537,129 @@ static void ads7846_rx(void *ads)
                 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 */
+         * 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);
+#ifdef VERBOSE
+                pr_debug("%s: ignored %d pressure %d\n",
+                        ts->spi->dev.bus_id, ts->tc.ignore, Rt);
+#endif
+                hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+                              HRTIMER_REL);
                 return;
         }
 
-        /* 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).
+        /* 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.
          *
-         * 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 ...
+         * 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 (!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;
-        }
-
         if (Rt) {
-                input_report_abs(input_dev, ABS_X, x);
-                input_report_abs(input_dev, ABS_Y, y);
-                sync = 1;
-        }
-
-        if (sync) {
-                input_report_abs(input_dev, ABS_PRESSURE, Rt);
-                input_sync(input_dev);
-        }
+                struct input_dev *input = ts->input;
 
-#ifdef  VERBOSE
-        if (Rt || ts->pendown)
-                pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id,
-                        x, y, Rt, Rt ? "" : " UP");
+                if (!ts->pendown) {
+                        input_report_key(input, BTN_TOUCH, 1);
+                        ts->pendown = 1;
+#ifdef VERBOSE
+                        dev_dbg(&ts->spi->dev, "DOWN\n");
 #endif
+                }
+                input_report_abs(input, ABS_X, x);
+                input_report_abs(input, ABS_Y, y);
+                input_report_abs(input, ABS_PRESSURE, Rt);
 
-        spin_lock_irqsave(&ts->lock, flags);
-
-        ts->pendown = (Rt != 0);
-        mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
+                input_sync(input);
+#ifdef VERBOSE
+                dev_dbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
+#endif
+        }
 
-        spin_unlock_irqrestore(&ts->lock, flags);
+        hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), HRTIMER_REL);
 }
 
-static void ads7846_debounce(void *ads)
+static int ads7846_debounce(void *ads, int data_idx, int *val)
 {
         struct ads7846          *ts = ads;
-        struct spi_message      *m;
-        struct spi_transfer     *t;
-        int                     val;
-        int                     status;
 
-        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)) {
+        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->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;
-                        /* Last message will contain ads7846_rx() as the
-                         * completion function.
-                         */
-                        m = ts->last_msg;
+                        return ADS7846_FILTER_IGNORE;
                 }
-                /* 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;
-                        m++;
-                } else
+                        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 void ads7846_rx_val(void *ads)
+{
+        struct ads7846 *ts = ads;
+        struct spi_message *m;
+        struct spi_transfer *t;
+        u16 *rx_val;
+        int val;
+        int action;
+        int status;
+
+        m = &ts->msg[ts->msg_idx];
+        t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
+        rx_val = t->rx_buf;
+
+        /* 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_cpu(*rx_val) >> 3;
+
+        action = ts->filter(ts->filter_data, ts->msg_idx, &val);
+        switch (action) {
+        case ADS7846_FILTER_REPEAT:
+                break;
+        case ADS7846_FILTER_IGNORE:
+                ts->tc.ignore = 1;
+                /* Last message will contain ads7846_rx() as the
+                 * completion function.
+                 */
+                m = ts->last_msg;
+                break;
+        case ADS7846_FILTER_OK:
+                *rx_val = val;
+                ts->tc.ignore = 0;
+                m = &ts->msg[++ts->msg_idx];
+                break;
+        default:
+                BUG();
         }
         status = spi_async(ts->spi, m);
         if (status)
@@ -504,21 +667,34 @@ static void ads7846_debounce(void *ads)
                                 status);
 }
 
-static void ads7846_timer(unsigned long handle)
+static int ads7846_timer(struct hrtimer *handle)
 {
-        struct ads7846  *ts = (void *)handle;
+        struct ads7846  *ts = container_of(handle, struct ads7846, timer);
         int             status = 0;
 
         spin_lock_irq(&ts->lock);
 
-        if (unlikely(ts->msg_idx && !ts->pendown)) {
+        if (unlikely(!ts->get_pendown_state() ||
+                     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;
+#ifdef VERBOSE
+                        dev_dbg(&ts->spi->dev, "UP\n");
+#endif
+                }
+
                 /* 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;
@@ -528,6 +704,7 @@ static void ads7846_timer(unsigned long handle)
         }
 
         spin_unlock_irq(&ts->lock);
+        return HRTIMER_NORESTART;
 }
 
 static irqreturn_t ads7846_irq(int irq, void *handle)
@@ -546,7 +723,8 @@ static irqreturn_t ads7846_irq(int irq, void *handle)
                         ts->irq_disabled = 1;
                         disable_irq(ts->spi->irq);
                         ts->pending = 1;
-                        mod_timer(&ts->timer, jiffies);
+                        hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
+                                        HRTIMER_REL);
                 }
         }
         spin_unlock_irqrestore(&ts->lock, flags);
@@ -632,6 +810,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         struct ads7846_platform_data    *pdata = spi->dev.platform_data;
         struct spi_message              *m;
         struct spi_transfer             *x;
+        int                             vref;
         int                             err;
 
         if (!spi->irq) {
@@ -665,6 +844,10 @@ static int __devinit ads7846_probe(struct spi_device *spi)
          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
          */
         spi->bits_per_word = 8;
+        spi->mode = SPI_MODE_1;
+        err = spi_setup(spi);
+        if (err < 0)
+                return err;
 
         ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
         input_dev = input_allocate_device();
@@ -679,8 +862,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         ts->spi = spi;
         ts->input = input_dev;
 
-        init_timer(&ts->timer);
-        ts->timer.data = (unsigned long) ts;
+        hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_REL);
         ts->timer.function = ads7846_timer;
 
         spin_lock_init(&ts->lock);
@@ -689,14 +871,25 @@ 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;
-        if (pdata->debounce_max) {
+
+        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;
-                if (ts->debounce_rep > ts->debounce_max + 1)
-                        ts->debounce_rep = ts->debounce_max - 1;
+                ts->filter = ads7846_debounce;
+                ts->filter_data = ts;
         } else
-                ts->debounce_tol = ~0;
+                ts->filter = ads7846_no_filter;
         ts->get_pendown_state = pdata->get_pendown_state;
 
         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id);
@@ -718,6 +911,8 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         input_set_abs_params(input_dev, ABS_PRESSURE,
                         pdata->pressure_min, pdata->pressure_max, 0, 0);
 
+        vref = pdata->keep_vref_on;
+
         /* set up the transfers to read touchscreen state; this assumes we
          * use formula #2 for pressure, not #3.
          */
@@ -727,7 +922,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         spi_message_init(m);
 
         /* y- still on; turn on only y+ (and ADC) */
-        ts->read_y = READ_Y;
+        ts->read_y = READ_Y(vref);
         x->tx_buf = &ts->read_y;
         x->len = 1;
         spi_message_add_tail(x, m);
@@ -737,7 +932,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         x->len = 2;
         spi_message_add_tail(x, m);
 
-        m->complete = ads7846_debounce;
+        m->complete = ads7846_rx_val;
         m->context = ts;
 
         m++;
@@ -745,7 +940,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 
         /* turn y- off, x+ on, then leave in lowpower */
         x++;
-        ts->read_x = READ_X;
+        ts->read_x = READ_X(vref);
         x->tx_buf = &ts->read_x;
         x->len = 1;
         spi_message_add_tail(x, m);
@@ -755,7 +950,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         x->len = 2;
         spi_message_add_tail(x, m);
 
-        m->complete = ads7846_debounce;
+        m->complete = ads7846_rx_val;
         m->context = ts;
 
         /* turn y+ off, x- on; we'll use formula #2 */
@@ -764,7 +959,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 spi_message_init(m);
 
                 x++;
-                ts->read_z1 = READ_Z1;
+                ts->read_z1 = READ_Z1(vref);
                 x->tx_buf = &ts->read_z1;
                 x->len = 1;
                 spi_message_add_tail(x, m);
@@ -774,14 +969,14 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 x->len = 2;
                 spi_message_add_tail(x, m);
 
-                m->complete = ads7846_debounce;
+                m->complete = ads7846_rx_val;
                 m->context = ts;
 
                 m++;
                 spi_message_init(m);
 
                 x++;
-                ts->read_z2 = READ_Z2;
+                ts->read_z2 = READ_Z2(vref);
                 x->tx_buf = &ts->read_z2;
                 x->len = 1;
                 spi_message_add_tail(x, m);
@@ -791,7 +986,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 x->len = 2;
                 spi_message_add_tail(x, m);
 
-                m->complete = ads7846_debounce;
+                m->complete = ads7846_rx_val;
                 m->context = ts;
         }
 
@@ -820,31 +1015,24 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                         spi->dev.driver->name, ts)) {
                 dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
                 err = -EBUSY;
-                goto err_free_mem;
+                goto err_cleanup_filter;
         }
 
+        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; avoid
+        /* take a first sample, leaving nPENIRQ active and vREF off; avoid
          * the touchscreen, in case it's not connected.
          */
         (void) ads7846_read12_ser(&spi->dev,
                           READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
 
-        switch (ts->model) {
-        case 7846:
-                ts->attr_group = &ads7846_attr_group;
-                break;
-        case 7845:
-                ts->attr_group = &ads7845_attr_group;
-                break;
-        default:
-                ts->attr_group = &ads7843_attr_group;
-                break;
-        }
-        err = sysfs_create_group(&spi->dev.kobj, ts->attr_group);
+        err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
         if (err)
-                goto err_free_irq;
+                goto err_remove_hwmon;
 
         err = input_register_device(input_dev);
         if (err)
@@ -853,9 +1041,14 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         return 0;
 
  err_remove_attr_group:
-        sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
+        sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
+ err_remove_hwmon:
+        ads784x_hwmon_unregister(spi, ts);
  err_free_irq:
         free_irq(spi->irq, ts);
+ err_cleanup_filter:
+        if (ts->filter_cleanup)
+                ts->filter_cleanup(ts->filter_data);
  err_free_mem:
         input_free_device(input_dev);
         kfree(ts);
@@ -866,16 +1059,20 @@ 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, ts->attr_group);
+        sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
 
         free_irq(ts->spi->irq, ts);
         /* suspend left the IRQ disabled */
         enable_irq(ts->spi->irq);
 
+        if (ts->filter_cleanup)
+                ts->filter_cleanup(ts->filter_data);
+
         kfree(ts);
 
         dev_dbg(&spi->dev, "unregistered touchscreen\n");