/****************************************************************************
* drivers/input/mxt.c
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
/* Suppress verbose debug output so that we don't swamp the system */
#ifdef CONFIG_MXT_DISABLE_DEBUG_VERBOSE
# undef CONFIG_DEBUG_VERBOSE
#endif
#include <sys/types.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <semaphore.h>
#include <poll.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/arch.h>
#include <nuttx/fs/fs.h>
#include <nuttx/i2c.h>
#include <nuttx/wqueue.h>
#include <nuttx/input/touchscreen.h>
#include <nuttx/input/mxt.h>
#include "mxt.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Driver support ***********************************************************/
/* This format is used to construct the /dev/input[n] device driver path. It
* defined here so that it will be used consistently in all places.
*/
#define DEV_FORMAT "/dev/input%d"
#define DEV_NAMELEN 16
/* This is a value for the threshold that guarantees a big difference on the
* first pendown (but can't overflow).
*/
#define INVALID_POSITION 0x1000
/* Get a 16-bit value in little endian order (not necessarily aligned). The
* source data is in little endian order. The host byte order does not
* matter in this case.
*/
#define MXT_GETUINT16(p) \
(((uint16_t)(((FAR uint8_t*)(p))[1]) << 8) | \
(uint16_t)(((FAR uint8_t*)(p))[0]))
/****************************************************************************
* Private Types
****************************************************************************/
/* This enumeration describes the state of one contact.
*
* |
* v
* CONTACT_NONE (1) Touch
* / (1) ^ (3) (2) Release
* v \ (3) Event reported
* CONTACT_NEW CONTACT_LOST
* \ (3) ^ (2)
* v /
* CONTACT_REPORT
* \ (1) ^ (3)
* v /
* CONTACT_MOVE
*
* NOTE: This state transition diagram is simplified. There are a few other
* sneaky transitions to handle unexpected conditions.
*/
enum mxt_contact_e
{
CONTACT_NONE = 0, /* No contact */
CONTACT_NEW, /* New contact */
CONTACT_MOVE, /* Same contact, possibly different position */
CONTACT_REPORT, /* Contact reported */
CONTACT_LOST, /* Contact lost */
};
/* This structure describes the results of one MXT sample */
struct mxt_sample_s
{
uint8_t id; /* Sampled touch point ID */
uint8_t contact; /* Contact state (see enum mxt_contact_e) */
bool valid; /* True: x,y,pressure contain valid, sampled data */
uint16_t x; /* Measured X position */
uint16_t y; /* Measured Y position */
uint16_t lastx; /* Last reported X position */
uint16_t lasty; /* Last reported Y position */
uint8_t area; /* Contact area */
uint8_t pressure; /* Contact pressure */
};
/* This 7-bit 'info' data read from the MXT and that describes the
* characteristics of the particular maXTouch chip
*/
struct mxt_info_s
{
uint8_t family; /* MXT family ID */
uint8_t variant; /* MXT variant ID */
uint8_t version; /* MXT version number */
uint8_t build; /* MXT build number */
uint8_t xsize; /* Matrix X size */
uint8_t ysize; /* Matrix Y size */
uint8_t nobjects; /* Number of objects */
};
#define MXT_INFO_SIZE 7
/* Describes the state of the MXT driver */
struct mxt_dev_s
{
/* These are the retained references to the I2C device and to the
* lower half configuration data.
*/
FAR struct i2c_dev_s *i2c;
FAR const struct mxt_lower_s *lower;
/* This is the allocated array of object information */
FAR struct mxt_object_s *objtab;
/* This is an allocated array of sample data, one for each possible touch */
FAR struct mxt_sample_s *sample; /* Last sampled touch point data */
uint8_t nwaiters; /* Number of threads waiting for MXT data */
uint8_t id; /* Current touch point ID */
uint8_t nslots; /* Number of slots */
uint8_t crefs; /* Reference count */
/* Cached parameters from object table */
#ifdef MXT_SUPPORT_T6
uint8_t t6id; /* T6 report ID */
#endif
uint8_t t9idmin; /* T9 touch event report IDs */
uint8_t t9idmax;
#ifdef CONFIG_MXT_BUTTONS
uint8_t t19id; /* T19 button report ID */
#endif
volatile bool event; /* True: An unreported event is buffered */
sem_t devsem; /* Manages exclusive access to this structure */
sem_t waitsem; /* Used to wait for the availability of data */
uint32_t frequency; /* Current I2C frequency */
char phys[64]; /* Device physical location */
struct mxt_info_s info; /* Configuration info read from device */
struct work_s work; /* Supports the interrupt handling "bottom half" */
/* The following is a list if poll structures of threads waiting for
* driver events. The 'struct pollfd' reference for each open is also
* retained in the f_priv field of the 'struct file'.
*/
#ifndef CONFIG_DISABLE_POLL
struct pollfd *fds[CONFIG_MXT_NPOLLWAITERS];
#endif
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* MXT register access */
static int mxt_getreg(FAR struct mxt_dev_s *priv, uint16_t regaddr,
FAR uint8_t *buffer, size_t buflen);
static int mxt_putreg(FAR struct mxt_dev_s *priv, uint16_t regaddr,
FAR const uint8_t *buffer, size_t buflen);
/* MXT object/message access */
static FAR struct mxt_object_s *mxt_object(FAR struct mxt_dev_s *priv,
uint8_t type);
static int mxt_getmessage(FAR struct mxt_dev_s *priv,
FAR struct mxt_msg_s *msg);
static int mxt_putobject(FAR struct mxt_dev_s *priv, uint8_t type,
uint8_t offset, uint8_t value);
#if 0 /* Not used */
static int mxt_getobject(FAR struct mxt_dev_s *priv, uint8_t type,
uint8_t offset, FAR uint8_t *value);
#endif
static int mxt_flushmsgs(FAR struct mxt_dev_s *priv);
/* Poll support */
static void mxt_notify(FAR struct mxt_dev_s *priv);
/* Touch event waiting */
static inline int mxt_checksample(FAR struct mxt_dev_s *priv);
static inline int mxt_waitsample(FAR struct mxt_dev_s *priv);
/* Interrupt handling/position sampling */
#ifdef CONFIG_MXT_BUTTONS
static void mxt_button_event(FAR struct mxt_dev_s *priv,
FAR struct mxt_msg_s *msg);
#endif
static void mxt_touch_event(FAR struct mxt_dev_s *priv,
FAR struct mxt_msg_s *msg, int ndx);
static void mxt_worker(FAR void *arg);
static int mxt_interrupt(FAR const struct mxt_lower_s *lower,
FAR void *arg);
/* Character driver methods */
static int mxt_open(FAR struct file *filep);
static int mxt_close(FAR struct file *filep);
static ssize_t mxt_read(FAR struct file *filep, FAR char *buffer,
size_t len);
static int mxt_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
#ifndef CONFIG_DISABLE_POLL
static int mxt_poll(FAR struct file *filep, struct pollfd *fds, bool setup);
#endif
/* Initialization */
static int mxt_getinfo(struct mxt_dev_s *priv);
static int mxt_getobjtab(FAR struct mxt_dev_s *priv);
static int mxt_hwinitialize(FAR struct mxt_dev_s *priv);
/****************************************************************************
* Private Data
****************************************************************************/
/* This the vtable that supports the character driver interface */
static const struct file_operations mxt_fops =
{
mxt_open, /* open */
mxt_close, /* close */
mxt_read, /* read */
0, /* write */
0, /* seek */
mxt_ioctl /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, mxt_poll /* poll */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: mxt_getreg
****************************************************************************/
static int mxt_getreg(FAR struct mxt_dev_s *priv, uint16_t regaddr,
FAR uint8_t *buffer, size_t buflen)
{
struct i2c_msg_s msg[2];
uint8_t addrbuf[2];
int retries;
int ret;
/* Try up to three times to read the register */
for (retries = 1; retries <= 3; retries++)
{
ivdbg("retries=%d regaddr=%04x buflen=%d\n", retries, regaddr, buflen);
/* Set up to write the address */
addrbuf[0] = regaddr & 0xff;
addrbuf[1] = (regaddr >> 8) & 0xff;
msg[0].addr = priv->lower->address;
msg[0].flags = 0;
msg[0].buffer = addrbuf;
msg[0].length = 2;
/* Followed by the read data */
msg[1].addr = priv->lower->address;
msg[1].flags = I2C_M_READ;
msg[1].buffer = buffer;
msg[1].length = buflen;
/* Read the register data. The returned value is the number messages
* completed.
*/
ret = I2C_TRANSFER(priv->i2c, msg, 2);
if (ret < 0)
{
#ifdef CONFIG_I2C_RESET
/* Perhaps the I2C bus is locked up? Try to shake the bus free */
idbg("WARNING: I2C_TRANSFER failed: %d ... Resetting\n", ret);
ret = up_i2creset(priv->i2c);
if (ret < 0)
{
idbg("ERROR: up_i2creset failed: %d\n", ret);
break;
}
#else
idbg("ERROR: I2C_TRANSFER failed: %d\n", ret);
#endif
}
else
{
/* The I2C transfer was successful... break out of the loop and
* return the success indication.
*/
break;
}
}
/* Return the last status returned by I2C_TRANSFER */
return ret;
}
/****************************************************************************
* Name: mxt_putreg
****************************************************************************/
static int mxt_putreg(FAR struct mxt_dev_s *priv, uint16_t regaddr,
FAR const uint8_t *buffer, size_t buflen)
{
struct i2c_msg_s msg[2];
uint8_t addrbuf[2];
int retries;
int ret;
/* Try up to three times to read the register */
for (retries = 1; retries <= 3; retries++)
{
ivdbg("retries=%d regaddr=%04x buflen=%d\n", retries, regaddr, buflen);
/* Set up to write the address */
addrbuf[0] = regaddr & 0xff;
addrbuf[1] = (regaddr >> 8) & 0xff;
msg[0].addr = priv->lower->address;
msg[0].flags = 0;
msg[0].buffer = addrbuf;
msg[0].length = 2;
/* Followed by the write data (with no repeated start) */
msg[1].addr = priv->lower->address;
msg[1].flags = I2C_M_NORESTART;
msg[1].buffer = (FAR uint8_t *)buffer;
msg[1].length = buflen;
/* Write the register data. The returned value is the number messages
* completed.
*/
ret = I2C_TRANSFER(priv->i2c, msg, 2);
if (ret < 0)
{
#ifdef CONFIG_I2C_RESET
/* Perhaps the I2C bus is locked up? Try to shake the bus free */
idbg("WARNING: I2C_TRANSFER failed: %d ... Resetting\n", ret);
ret = up_i2creset(priv->i2c);
if (ret < 0)
{
idbg("ERROR: up_i2creset failed: %d\n", ret);
}
#else
idbg("ERROR: I2C_TRANSFER failed: %d\n", ret);
#endif
}
else
{
/* The I2C transfer was successful... break out of the loop and
* return the success indication.
*/
break;
}
}
/* Return the last status returned by I2C_TRANSFER */
return ret;
}
/****************************************************************************
* Name: mxt_object
****************************************************************************/
static FAR struct mxt_object_s *mxt_object(FAR struct mxt_dev_s *priv,
uint8_t type)
{
struct mxt_object_s *object;
int i;
/* Search the object table for the entry matching the type */
for (i = 0; i < priv->info.nobjects; i++)
{
object = &priv->objtab[i];
if (object->type == type)
{
/* Found it.. return the pointer to the object structure */
return object;
}
}
idbg("ERROR: Invalid object type: %d\n", type);
return NULL;
}
/****************************************************************************
* Name: mxt_getmessage
****************************************************************************/
static int mxt_getmessage(FAR struct mxt_dev_s *priv,
FAR struct mxt_msg_s *msg)
{
struct mxt_object_s *object;
uint16_t regaddr;
object = mxt_object(priv, MXT_GEN_MESSAGE_T5);
if (object == NULL)
{
idbg("ERROR: mxt_object failed\n");
return -EINVAL;
}
regaddr = MXT_GETUINT16(object->addr);
return mxt_getreg(priv, regaddr, (FAR uint8_t *)msg,
sizeof(struct mxt_msg_s));
}
/****************************************************************************
* Name: mxt_putobject
****************************************************************************/
static int mxt_putobject(FAR struct mxt_dev_s *priv, uint8_t type,
uint8_t offset, uint8_t value)
{
FAR struct mxt_object_s *object;
uint16_t regaddr;
object = mxt_object(priv, type);
if (object == NULL || offset >= object->size + 1)
{
return -EINVAL;
}
regaddr = MXT_GETUINT16(object->addr);
return mxt_putreg(priv, regaddr + offset, &value, 1);
}
/****************************************************************************
* Name: mxt_getobject
****************************************************************************/
#if 0 /* Not used */
static int mxt_getobject(FAR struct mxt_dev_s *priv, uint8_t type,
uint8_t offset, FAR uint8_t *value)
{
FAR struct mxt_object_s *object;
uint16_t regaddr;
object = mxt_object(priv, type);
if (object == NULL || offset >= object->size + 1)
{
return -EINVAL;
}
regaddr = MXT_GETUINT16(object->addr);
return mxt_getreg(priv, regaddr + offset, value, 1);
}
#endif
/****************************************************************************
* Name: mxt_flushmsgs
*
* Clear any pending messages be reading messages until there are no
* pending messages. This will force the CHG pin to the high state and
* prevent spurious initial interrupts.
*
****************************************************************************/
static int mxt_flushmsgs(FAR struct mxt_dev_s *priv)
{
struct mxt_msg_s msg;
int retries = 16;
int ret;
/* Read dummy message until there are no more to read (or until we have
* tried 10 times).
*/
do
{
ret = mxt_getmessage(priv, &msg);
if (ret < 0)
{
idbg("ERROR: mxt_getmessage failed: %d\n", ret);
return ret;
}
}
while (msg.id != 0xff && --retries > 0);
/* Complain if we exceed the retry limit */
if (retries <= 0)
{
idbg("ERROR: Failed to clear messages: ID=%02x\n", msg.id);
return -EBUSY;
}
return OK;
}
/****************************************************************************
* Name: mxt_notify
****************************************************************************/
static void mxt_notify(FAR struct mxt_dev_s *priv)
{
#ifndef CONFIG_DISABLE_POLL
int i;
#endif
/* If there are threads waiting for read data, then signal one of them
* that the read data is available.
*/
if (priv->nwaiters > 0)
{
/* After posting this semaphore, we need to exit because the maXTouch
* is no longer available.
*/
sem_post(&priv->waitsem);
}
/* If there are threads waiting on poll() for maXTouch data to become available,
* then wake them up now. NOTE: we wake up all waiting threads because we
* do not know that they are going to do. If they all try to read the data,
* then some make end up blocking after all.
*/
#ifndef CONFIG_DISABLE_POLL
for (i = 0; i < CONFIG_MXT_NPOLLWAITERS; i++)
{
struct pollfd *fds = priv->fds[i];
if (fds)
{
fds->revents |= POLLIN;
ivdbg("Report events: %02x\n", fds->revents);
sem_post(fds->sem);
}
}
#endif
}
/****************************************************************************
* Name: mxt_checksample
*
* Description:
* This function implements a test and clear of the priv->event flag.
* Called only from mxt_waitsample.
*
* Assumptions:
* - Scheduler must be locked to prevent the worker thread from running
* while this thread runs. The sample data is, of course, updated from
* the worker thread.
* - Interrupts must be disabled when this is called to (1) prevent posting
* of semaphores from interrupt handlers, and (2) to prevent sampled data
* from changing until it has been reported.
*
****************************************************************************/
static inline int mxt_checksample(FAR struct mxt_dev_s *priv)
{
/* Is there new maXTouch sample data available? */
if (priv->event)
{
/* Yes.. clear the flag and return success */
priv->event = false;
return OK;
}
/* No.. return failure */
return -EAGAIN;
}
/****************************************************************************
* Name: mxt_waitsample
*
* Wait until sample data is available. Called only from mxt_read.
*
* Assumptions:
* - Scheduler must be locked to prevent the worker thread from running
* while this thread runs. The sample data is, of course, updated from
* the worker thread.
*
****************************************************************************/
static inline int mxt_waitsample(FAR struct mxt_dev_s *priv)
{
irqstate_t flags;
int ret;
/* Interrupts me be disabled when this is called to (1) prevent posting
* of semaphores from interrupt handlers, and (2) to prevent sampled data
* from changing until it has been reported.
*/
flags = irqsave();
/* Now release the semaphore that manages mutually exclusive access to
* the device structure. This may cause other tasks to become ready to
* run, but they cannot run yet because pre-emption is disabled.
*/
sem_post(&priv->devsem);
/* Try to get the a sample... if we cannot, then wait on the semaphore
* that is posted when new sample data is available.
*/
while (mxt_checksample(priv) < 0)
{
/* Wait for a change in the maXTouch state */
priv->nwaiters++;
ret = sem_wait(&priv->waitsem);
priv->nwaiters--;
if (ret < 0)
{
/* If we are awakened by a signal, then we need to return
* the failure now.
*/
DEBUGASSERT(errno == EINTR);
ret = -EINTR;
goto errout;
}
}
/* Re-acquire the semaphore that manages mutually exclusive access to
* the device structure. We may have to wait here. But we have our sample.
* Interrupts and pre-emption will be re-enabled while we wait.
*/
ret = sem_wait(&priv->devsem);
errout:
/* Then re-enable interrupts. We might get interrupt here and there
* could be a new sample. But no new threads will run because we still
* have pre-emption disabled.
*/
irqrestore(flags);
return ret;
}
/****************************************************************************
* Name: mxt_button_event
****************************************************************************/
#ifdef CONFIG_MXT_BUTTONS
static void mxt_button_event(FAR struct mxt_dev_s *priv,
FAR struct mxt_msg_s *msg)
{
bool button;
int i;
/* REVISIT: Button inputs are currently ignored */
/* Buttons are active low and determined by the GPIO bit
* settings in byte 0 of the message data: A button is
* pressed if the corresponding bit is zero.
*/
for (i = 0; i < priv->lower->nbuttons; i++)
{
uint8_t bit = (MXT_GPIO0_MASK << i);
/* Does this implementation support the button? */
if ((priv->lower->bmask & bit) != 0)
{
/* Yes.. get the button state */
button = (msg->body[0] & mask) == 0;
/* Now what? */
UNUSED(button);
}
}
}
#endif
/****************************************************************************
* Name: mxt_touch_event
****************************************************************************/
static void mxt_touch_event(FAR struct mxt_dev_s *priv,
FAR struct mxt_msg_s *msg, int ndx)
{
FAR struct mxt_sample_s *sample;
uint16_t x;
uint16_t y;
uint8_t area;
uint8_t pressure;
uint8_t status;
/* Extract the 12-bit X and Y positions */
x = ((uint16_t)msg->body[1] << 4) | (((uint16_t)msg->body[3] >> 4) & 0x0f);
y = ((uint16_t)msg->body[2] << 4) | (((uint16_t)msg->body[3] & 0x0f));
/* Swap X/Y as necessary */
if (priv->lower->swapxy)
{
uint16_t tmp = x;
y = x;
x = tmp;
}
/* Extract area pressure and status */
area = msg->body[4];
pressure = msg->body[5];
status = msg->body[0];
ivdbg("ndx=%u status=%02x pos(%u,%u) area=%u pressure=%u\n",
ndx, status, x, y, area, pressure);
/* The normal sequence that we would see for a touch would be something
* like:
*
* 1. MXT_DETECT + MXT_PRESS
* 2. MXT_DETECT + MXT_AMP
* 3. MXT_DETECT + MXT_MOVE + MXT_AMP
* 4. MXT_RELEASE
*
* So we really only need to check MXT_DETECT to drive this state machine.
*/
/* Is this a loss of contact? */
sample = &priv->sample[ndx];
if ((status & MXT_DETECT) == 0)
{
/* Ignore the event if there was no contact to be lost:
*
* CONTACT_NONE = No touch and loss-of-contact already reported
* CONTACT_LOST = No touch and unreported loss-of-contact.
*/
if (sample->contact == CONTACT_NONE)
{
/* Return without posting any event */
return;
}
/* State is one of CONTACT_NEW, CONTACT_MOVE, CONTACT_REPORT or
* CONTACT_LOST.
*
* NOTE: Here we do not check for these other states because there is
* not much that can be done anyway. The transition to CONTACK_LOST
* really only makes sense if the preceding state was CONTACT_REPORT.
* If we were in (unreported) CONTACT_NEW or CONTACT_MOVE states, then
* this will overwrite that event and it will not be reported. This
* opens the possibility for contact lost reports when no contact was
* ever reported.
*
* We could improve this be leaving the unreported states in place,
* remembering that the contact was lost, and then reporting the loss-
* of-contact after touch state is reported.
*/
sample->contact = CONTACT_LOST;
/* Reset the last position so that we guarantee that the next position
* will pass the thresholding test.
*/
sample->lastx = INVALID_POSITION;
sample->lasty = INVALID_POSITION;
}
else
{
/* It is a touch event. If the last loss-of-contact event has not
* been processed yet, then have to bump up the touch identifier and
* hope that the client is smart enough to infer the loss-of-contact
* event for the preceding touch.
*/
if (sample->contact == CONTACT_LOST)
{
priv->id++;
}
/* Save the measurements */
sample->x = x;
sample->y = y;
sample->area = area;
sample->pressure = pressure;
sample->valid = true;
/* If this is not the first touch report, then report it as a move:
* Same contact, same ID, but with a new, updated position.
* The CONTACT_REPORT state means that a contacted has been detected,
* but all contact events have been successfully reported.
*/
if (sample->contact == CONTACT_REPORT)
{
uint16_t xdiff;
uint16_t ydiff;
/* Not a new contact. Check if the new measurements represent a
* non-trivial change in position. A trivial change is detected
* by comparing the change in position since the last report
* against configurable threshold values.
*
* REVISIT: Should a large change in pressure also generate a
* event?
*/
xdiff = x > sample->lastx ? (x - sample->lastx) : (sample->lastx - x);
ydiff = y > sample->lasty ? (y - sample->lasty) : (sample->lasty - y);
/* Check the thresholds */
if (xdiff >= CONFIG_MXT_THRESHX || ydiff >= CONFIG_MXT_THRESHY)
{
/* Report a contact move event. This state will be set back
* to CONTACT_REPORT after it been reported.
*/
sample->contact = CONTACT_MOVE;
/* Update the last position for next threshold calculations */
sample->lastx = x;
sample->lasty = y;
}
else
{
/* Bail without reporting anything for this event */
return;
}
}
/* If we have seen this contact before but it has not yet been
* reported, then do nothing other than overwrite the positional
* data.
*
* This the state must be one of CONTACT_NONE or CONTACT_LOST (see
* above) and we have a new contact with a new ID.
*/
else if (sample->contact != CONTACT_NEW &&
sample->contact != CONTACT_MOVE)
{
/* First contact. Save the contact event and assign a new
* ID to the contact.
*/
sample->contact = CONTACT_NEW;
sample->id = priv->id++;
/* Update the last position for next threshold calculations */
sample->lastx = x;
sample->lasty = y;
/* This state will be set to CONTACT_REPORT after it
* been reported.
*/
}
}
/* Indicate the availability of new sample data for this ID and notify
* any waiters that new maXTouch data is available
*/
priv->event = true;
mxt_notify(priv);
}
/****************************************************************************
* Name: mxt_worker
****************************************************************************/
static void mxt_worker(FAR void *arg)
{
FAR struct mxt_dev_s *priv = (FAR struct mxt_dev_s *)arg;
FAR const struct mxt_lower_s *lower;
struct mxt_msg_s msg;
uint8_t id;
int retries;
int ret;
ASSERT(priv != NULL);
/* Get a pointer the callbacks for convenience (and so the code is not so
* ugly).
*/
lower = priv->lower;
DEBUGASSERT(lower != NULL);
/* Get exclusive access to the MXT driver data structure */
do
{
ret = sem_wait(&priv->devsem);
DEBUGASSERT(ret == 0 || errno == EINTR);
}
while (ret < 0);
/* Loop, processing each message from the maXTouch */
retries = 0;
do
{
/* Retrieve the next message from the maXTouch */
ret = mxt_getmessage(priv, &msg);
if (ret < 0)
{
idbg("ERROR: mxt_getmessage failed: %d\n", ret);
goto errout_with_semaphore;
}
id = msg.id;
#ifdef MXT_SUPPORT_T6
/* Check for T6 */
if (id == priv->t6id)
{
uint32_t chksum;
int status;
status = msg.body[0];
chksum = (uint32_t)msg.body[1] |
((uint32_t)msg.body[2] << 8) |
((uint32_t)msg.body[3] << 16);
ivdbg("T6: status: %02x checksum: %06lx\n",
status, (unsigned long)chksum);
retries = 0;
}
else
#endif
/* Check for T9 */
if (id >= priv->t9idmin && id <= priv->t9idmax)
{
mxt_touch_event(priv, &msg, id - priv->t9idmin);
retries = 0;
}
#ifdef CONFIG_MXT_BUTTONS
/* Check for T19 */
else if (msg.id == priv->t19id)
{
mxt_button_event(priv, &msg);
retries = 0;
}
#endif
/* 0xff marks the end of the messages; any other message IDs are ignored
* (after complaining a little).
*/
else if (msg.id != 0xff)
{
ivdbg("Ignored: id=%u message={%02x %02x %02x %02x %02x %02x %02x}\n",
msg.id, msg.body[0], msg.body[1], msg.body[2], msg.body[3],
msg.body[4], msg.body[5], msg.body[6]);
retries++;
}
}
while (id != 0xff && retries < 16);
errout_with_semaphore:
/* Release our lock on the MXT device */
sem_post(&priv->devsem);
/* Acknowledge and re-enable maXTouch interrupts */
MXT_CLEAR(lower);
MXT_ENABLE(lower);
}
/****************************************************************************
* Name: mxt_interrupt
****************************************************************************/
static int mxt_interrupt(FAR const struct mxt_lower_s *lower, FAR void *arg)
{
FAR struct mxt_dev_s *priv = (FAR struct mxt_dev_s *)arg;
int ret;
/* Get a pointer the callbacks for convenience (and so the code is not so
* ugly).
*/
DEBUGASSERT(lower != NULL && priv != NULL);
/* Disable further interrupts */
MXT_DISABLE(lower);
/* Transfer processing to the worker thread. Since maXTouch interrupts are
* disabled while the work is pending, no special action should be required
* to protected the work queue.
*/
DEBUGASSERT(priv->work.worker == NULL);
ret = work_queue(HPWORK, &priv->work, mxt_worker, priv, 0);
if (ret != 0)
{
illdbg("Failed to queue work: %d\n", ret);
}
/* Clear any pending interrupts and return success */
lower->clear(lower);
return OK;
}
/****************************************************************************
* Name: mxt_open
****************************************************************************/
static int mxt_open(FAR struct file *filep)
{
FAR struct inode *inode;
FAR struct mxt_dev_s *priv;
uint8_t tmp;
int ret;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct mxt_dev_s *)inode->i_private;
/* Get exclusive access to the driver data structure */
ret = sem_wait(&priv->devsem);
if (ret < 0)
{
/* This should only happen if the wait was cancelled by an signal */
DEBUGASSERT(errno == EINTR);
return -EINTR;
}
/* Increment the reference count */
tmp = priv->crefs + 1;
if (tmp == 0)
{
/* More than 255 opens; uint8_t overflows to zero */
idbg("ERROR: Too many opens: %d\n", priv->crefs);
ret = -EMFILE;
goto errout_with_sem;
}
/* When the reference increments to 1, this is the first open event
* on the driver.. and an opportunity to do any one-time initialization.
*/
if (tmp == 1)
{
/* Touch enable */
ret = mxt_putobject(priv, MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0x83);
if (ret < 0)
{
idbg("ERROR: Failed to enable touch: %d\n", ret);
goto errout_with_sem;
}
/* Clear any pending messages by reading all messages. This will
* force the CHG interrupt pin to the high state and prevent spurious
* interrupts when they are enabled.
*/
ret = mxt_flushmsgs(priv);
if (ret < 0)
{
idbg("ERROR: mxt_flushmsgs failed: %d\n", ret);
mxt_putobject(priv, MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0);
goto errout_with_sem;
}
/* Enable touch interrupts */
MXT_ENABLE(priv->lower);
}
/* Save the new open count on success */
priv->crefs = tmp;
errout_with_sem:
sem_post(&priv->devsem);
return ret;
}
/****************************************************************************
* Name: mxt_close
****************************************************************************/
static int mxt_close(FAR struct file *filep)
{
FAR struct inode *inode;
FAR struct mxt_dev_s *priv;
int ret;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct mxt_dev_s *)inode->i_private;
/* Get exclusive access to the driver data structure */
ret = sem_wait(&priv->devsem);
if (ret < 0)
{
/* This should only happen if the wait was cancelled by an signal */
DEBUGASSERT(errno == EINTR);
return -EINTR;
}
/* Decrement the reference count unless it would decrement a negative
* value. When the count decrements to zero, there are no further
* open references to the driver.
*/
if (priv->crefs >= 1)
{
if (--priv->crefs < 1)
{
/* Disable touch interrupts */
MXT_ENABLE(priv->lower);
/* Touch disable */
ret = mxt_putobject(priv, MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0);
if (ret < 0)
{
idbg("ERROR: Failed to disable touch: %d\n", ret);
}
}
}
sem_post(&priv->devsem);
return OK;
}
/****************************************************************************
* Name: mxt_read
****************************************************************************/
static ssize_t mxt_read(FAR struct file *filep, FAR char *buffer, size_t len)
{
FAR struct inode *inode;
FAR struct mxt_dev_s *priv;
ssize_t samplesize;
int ncontacts;
int ret;
int i;
int j;
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct mxt_dev_s *)inode->i_private;
/* Verify that the caller has provided a buffer large enough to receive
* the touch data.
*/
if (len < SIZEOF_TOUCH_SAMPLE_S(1))
{
/* We could provide logic to break up a touch report into segments and
* handle smaller reads... but why?
*/
return -ENOSYS;
}
/* Get exclusive access to the driver data structure */
ret = sem_wait(&priv->devsem);
if (ret < 0)
{
/* This should only happen if the wait was cancelled by an signal */
DEBUGASSERT(errno == EINTR);
return -EINTR;
}
/* Locking the scheduler will prevent the worker thread from running
* until we finish here.
*/
sched_lock();
/* Try to read sample data. */
ret = mxt_checksample(priv);
if (ret < 0)
{
/* Sample data is not available now. We would ave to wait to get
* receive sample data. If the user has specified the O_NONBLOCK
* option, then just return an error.
*/
if (filep->f_oflags & O_NONBLOCK)
{
ret = -EAGAIN;
goto errout;
}
/* Wait for sample data */
ret = mxt_waitsample(priv);
if (ret < 0)
{
/* We might have been awakened by a signal */
goto errout;
}
}
/* In any event, we now have sampled maXTouch data that we can report
* to the caller. First, count the number of valid contacts.
*/
samplesize = 0;
ncontacts = 0;
for (i = 0; i < priv->nslots; i++)
{
FAR struct mxt_sample_s *sample = &priv->sample[i];
/* Do we need to report this? We need to report the event if
* it is CONTACT_LOST or CONTACT_REPORT or CONTACT_MOVE (with new,
* valid positional data).
*/
if (sample->contact == CONTACT_LOST ||
sample->contact == CONTACT_NEW ||
sample->contact == CONTACT_MOVE)
{
int newcount = ncontacts + 1;
ssize_t newsize = SIZEOF_TOUCH_SAMPLE_S(newcount);
/* Would this sample exceed the buffer size provided by the
* caller?
*/
if (newsize > len)
{
/* Yes.. break out of the loop using the previous size and
* count.
*/
break;
}
/* Save the new size and count */
ncontacts = newcount;
samplesize = newsize;
}
}
/* Did we find any valid samples? */
if (ncontacts > 0)
{
FAR struct touch_sample_s *report = (FAR struct touch_sample_s *)buffer;
/* Yes, copy the sample data into the user bufer */
memset(report, 0, SIZEOF_TOUCH_SAMPLE_S(ncontacts));
report->npoints = ncontacts;
for (i = 0, j= 0; i < priv->nslots && j < ncontacts; i++)
{
FAR struct mxt_sample_s *sample = &priv->sample[i];
/* Do we need to report this? We need to report the event if
* it is CONTACT_LOST or CONTACT_REPORT or CONTACT_MOVE (with new,
* valid positional data).
*/
if (sample->contact == CONTACT_LOST ||
sample->contact == CONTACT_NEW ||
sample->contact == CONTACT_MOVE)
{
/* Yes.. transfer the sample data */
FAR struct touch_point_s *point = &report->point[j];
j++;
/* REVISIT: height and width are not set, area is
* not used.
*/
point->id = sample->id;
point->x = sample->x;
point->y = sample->y;
point->pressure = sample->pressure;
/* Report the appropriate flags */
if (sample->contact == CONTACT_LOST)
{
/* The contact was lost. Is the positional data
* valid? This is important to know because the release
* will be sent to the window based on its last positional
* data.
*/
if (sample->valid)
{
point->flags = TOUCH_UP | TOUCH_ID_VALID |
TOUCH_POS_VALID | TOUCH_PRESSURE_VALID;
}
else
{
point->flags = TOUCH_UP | TOUCH_ID_VALID;
}
/* Change to CONTACT_NONE to indicate that the sample
* has been reported. From here it can change only
* to CONTACT_REPORT (with a new ID).
*/
sample->contact = CONTACT_NONE;
}
else
{
/* We have contact. Is it the first contact? */
if (sample->contact == CONTACT_NEW)
{
/* Yes.. first contact. */
point->flags = TOUCH_DOWN | TOUCH_ID_VALID |
TOUCH_POS_VALID;
}
else /* if (sample->contact == CONTACT_MOVE) */
{
/* No.. then it must be movement of the same contact */
point->flags = TOUCH_MOVE | TOUCH_ID_VALID |
TOUCH_POS_VALID;
}
/* Change to CONTACT_REPORT to indicate that the sample
* has been reported. From here is can change to
* CONTACT_LOST (same ID), CONTACT_MOVE (same ID) or back
* to CONTACT_NEW (new ID).
*/
sample->contact = CONTACT_REPORT;
/* A pressure measurement of zero means that pressure is not
* available */
if (point->pressure != 0)
{
point->flags |= TOUCH_PRESSURE_VALID;
}
}
/* In any case, the sample data has been reported and is no
* longer valid.
*/
sample->valid = false;
}
}
}
ret = samplesize;
errout:
sched_unlock();
sem_post(&priv->devsem);
return ret;
}
/****************************************************************************
* Name:mxt_ioctl
****************************************************************************/
static int mxt_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode;
FAR struct mxt_dev_s *priv;
int ret;
ivdbg("cmd: %d arg: %ld\n", cmd, arg);
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct mxt_dev_s *)inode->i_private;
/* Get exclusive access to the driver data structure */
ret = sem_wait(&priv->devsem);
if (ret < 0)
{
/* This should only happen if the wait was cancelled by an signal */
DEBUGASSERT(errno == EINTR);
return -EINTR;
}
/* Process the IOCTL by command */
switch (cmd)
{
case TSIOC_SETFREQUENCY: /* arg: Pointer to uint32_t frequency value */
{
FAR uint32_t *ptr = (FAR uint32_t *)((uintptr_t)arg);
DEBUGASSERT(priv->lower != NULL && ptr != NULL);
priv->frequency = I2C_SETFREQUENCY(priv->i2c, *ptr);
}
break;
case TSIOC_GETFREQUENCY: /* arg: Pointer to uint32_t frequency value */
{
FAR uint32_t *ptr = (FAR uint32_t *)((uintptr_t)arg);
DEBUGASSERT(priv->lower != NULL && ptr != NULL);
*ptr = priv->frequency;
}
break;
default:
ret = -ENOTTY;
break;
}
sem_post(&priv->devsem);
return ret;
}
/****************************************************************************
* Name: mxt_poll
****************************************************************************/
#ifndef CONFIG_DISABLE_POLL
static int mxt_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup)
{
FAR struct inode *inode;
FAR struct mxt_dev_s *priv;
int ret;
int i;
ivdbg("setup: %d\n", (int)setup);
DEBUGASSERT(filep && fds);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct mxt_dev_s *)inode->i_private;
/* Are we setting up the poll? Or tearing it down? */
ret = sem_wait(&priv->devsem);
if (ret < 0)
{
/* This should only happen if the wait was cancelled by an signal */
DEBUGASSERT(errno == EINTR);
return -EINTR;
}
if (setup)
{
/* Ignore waits that do not include POLLIN */
if ((fds->events & POLLIN) == 0)
{
idbg("Missing POLLIN: revents: %08x\n", fds->revents);
ret = -EDEADLK;
goto errout;
}
/* This is a request to set up the poll. Find an available
* slot for the poll structure reference
*/
for (i = 0; i < CONFIG_MXT_NPOLLWAITERS; i++)
{
/* Find an available slot */
if (!priv->fds[i])
{
/* Bind the poll structure and this slot */
priv->fds[i] = fds;
fds->priv = &priv->fds[i];
break;
}
}
if (i >= CONFIG_MXT_NPOLLWAITERS)
{
idbg("No availabled slot found: %d\n", i);
fds->priv = NULL;
ret = -EBUSY;
goto errout;
}
/* Should we immediately notify on any of the requested events? */
if (priv->event)
{
mxt_notify(priv);
}
}
else if (fds->priv)
{
/* This is a request to tear down the poll. */
struct pollfd **slot = (struct pollfd **)fds->priv;
DEBUGASSERT(slot != NULL);
/* Remove all memory of the poll setup */
*slot = NULL;
fds->priv = NULL;
}
errout:
sem_post(&priv->devsem);
return ret;
}
#endif
/****************************************************************************
* Name: mxt_getinfo
****************************************************************************/
static int mxt_getinfo(struct mxt_dev_s *priv)
{
int ret;
/* Read 7-byte information block starting at address MXT_INFO */
ret = mxt_getreg(priv, MXT_INFO, (FAR uint8_t *)&priv->info,
sizeof(struct mxt_info_s));
if (ret < 0)
{
idbg("ERROR: mxt_getreg failed: %d\n", ret);
return ret;
}
return OK;
}
/****************************************************************************
* Name: mxt_getobjtab
****************************************************************************/
static int mxt_getobjtab(FAR struct mxt_dev_s *priv)
{
FAR struct mxt_object_s *object;
size_t tabsize;
uint8_t idmin;
uint8_t idmax;
uint8_t id;
int ret;
int i;
/* Read the size of the object table */
tabsize = priv->info.nobjects * sizeof(struct mxt_object_s);
ret = mxt_getreg(priv, MXT_OBJECT_START, (FAR uint8_t *)priv->objtab,
tabsize);
if (ret < 0)
{
idbg("ERROR: Failed to object table size: %d\n", ret);
return ret;
}
/* Search through the object table. Find the values associated with
* certain object types and save those ID.Valid report IDs start at ID=1.
*/
for (i = 0, id = 1; i < priv->info.nobjects; i++)
{
object = &priv->objtab[i];
if (object->nids > 0)
{
idmin = id;
id += object->nids * (object->ninstances + 1);
idmax = id - 1;
}
else
{
idmin = 0;
idmax = 0;
}
ivdbg("%2d. type %2d addr %04x size: %d instances: %d IDs: %u-%u\n",
i, object->type, MXT_GETUINT16(object->addr), object->size + 1,
object->ninstances + 1, idmin, idmax);
switch (object->type)
{
#ifdef MXT_SUPPORT_T6
case MXT_GEN_COMMAND_T6:
priv->t6id = idmin;
break;
#endif
case MXT_TOUCH_MULTI_T9:
priv->t9idmin = idmin;
priv->t9idmax = idmax;
break;
#ifdef CONFIG_MXT_BUTTONS
case MXT_SPT_GPIOPWM_T19:
priv->t19id = idmin;
break;
#endif
default:
break;
}
}
return OK;
}
/****************************************************************************
* Name: mxt_hwinitialize
****************************************************************************/
static int mxt_hwinitialize(FAR struct mxt_dev_s *priv)
{
struct mxt_info_s *info = &priv->info;
unsigned int nslots;
uint8_t regval;
int ret;
/* Set the selected I2C frequency */
priv->frequency = I2C_SETFREQUENCY(priv->i2c, priv->lower->frequency);
/* Read the info registers from the device */
ret = mxt_getinfo(priv);
if (ret < 0)
{
idbg("ERROR: Failed to read info registers: %d\n", ret);
return ret;
}
/* Allocate memory for the object table */
priv->objtab = kmm_zalloc(info->nobjects * sizeof(struct mxt_object_s));
if (priv->objtab == NULL)
{
idbg("ERROR: Failed to allocate object table\n");
return -ENOMEM;
}
/* Get object table information */
ret = mxt_getobjtab(priv);
if (ret < 0)
{
goto errout_with_objtab;
}
/* Perform a soft reset */
ret = mxt_putobject(priv, MXT_GEN_COMMAND_T6, MXT_COMMAND_RESET, 1);
if (ret < 0)
{
idbg("ERROR: Soft reset failed: %d\n", ret);
goto errout_with_objtab;
}
usleep(MXT_RESET_TIME);
/* Update matrix size in the info structure */
ret = mxt_getreg(priv, MXT_MATRIX_X_SIZE, (FAR uint8_t *)®val, 1);
if (ret < 0)
{
idbg("ERROR: Failed to get X size: %d\n", ret);
goto errout_with_objtab;
}
info->xsize = regval;
ret = mxt_getreg(priv, MXT_MATRIX_Y_SIZE, (FAR uint8_t *)®val, 1);
if (ret < 0)
{
idbg("ERROR: Failed to get Y size: %d\n", ret);
goto errout_with_objtab;
}
info->ysize = regval;
ivdbg("Family: %u variant: %u version: %u.%u.%02x\n",
info->family, info->variant, info->version >> 4, info->version & 0x0f,
info->build);
ivdbg("Matrix size: (%u,%u) objects: %u\n",
info->xsize, info->ysize, info->nobjects);
/* How many multi touch "slots" */
nslots = priv->t9idmax - priv->t9idmin + 1;
DEBUGASSERT(nslots > 0 && nslots < 256);
priv->nslots = nslots;
/* Allocate a place to hold sample data for each slot */
priv->sample = (FAR struct mxt_sample_s *)
kmm_zalloc(nslots * sizeof(struct mxt_sample_s));
if (priv->sample == NULL)
{
idbg("ERROR: Failed to allocate object table\n");
goto errout_with_objtab;
}
return OK;
/* Error exits */
errout_with_objtab:
kmm_free(priv->objtab);
priv->objtab = NULL;
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mxt_register
*
* Description:
* Configure the maXTouch to use the provided I2C device instance. This
* will register the driver as /dev/inputN where N is the minor device
* number
*
* Input Parameters:
* i2c - An I2C driver instance
* lower - Persistent board configuration data
* minor - The input device minor number
*
* Returned Value:
* Zero is returned on success. Otherwise, a negated errno value is
* returned to indicate the nature of the failure.
*
****************************************************************************/
int mxt_register(FAR struct i2c_dev_s *i2c,
FAR const struct mxt_lower_s * const lower, int minor)
{
FAR struct mxt_dev_s *priv;
char devname[DEV_NAMELEN];
int ret;
ivdbg("i2c: %p minor: %d\n", i2c, minor);
/* Debug-only sanity checks */
DEBUGASSERT(i2c != NULL && lower != NULL && minor >= 0 && minor < 100);
/* Create and initialize a maXTouch device driver instance */
priv = (FAR struct mxt_dev_s *)kmm_zalloc(sizeof(struct mxt_dev_s));
if (priv == NULL)
{
idbg("ERROR: Failed allocate device structure\n");
return -ENOMEM;
}
/* Initialize the ADS7843E device driver instance */
memset(priv, 0, sizeof(struct mxt_dev_s));
priv->i2c = i2c; /* Save the SPI device handle */
priv->lower = lower; /* Save the board configuration */
sem_init(&priv->devsem, 0, 1); /* Initialize device semaphore */
sem_init(&priv->waitsem, 0, 0); /* Initialize event wait semaphore */
/* Make sure that interrupts are disabled */
MXT_CLEAR(lower);
MXT_DISABLE(lower);
/* Attach the interrupt handler */
ret = MXT_ATTACH(lower, mxt_interrupt, priv);
if (ret < 0)
{
idbg("Failed to attach interrupt\n");
goto errout_with_priv;
}
/* Configure the MXT hardware */
ret = mxt_hwinitialize(priv);
if (ret < 0)
{
idbg("ERROR: mxt_hwinitialize failed: %d\n", ret);
goto errout_with_irq;
}
/* Register the device as an input device */
(void)snprintf(devname, DEV_NAMELEN, DEV_FORMAT, minor);
ivdbg("Registering %s\n", devname);
ret = register_driver(devname, &mxt_fops, 0666, priv);
if (ret < 0)
{
idbg("register_driver() failed: %d\n", ret);
goto errout_with_hwinit;
}
/* And return success. MXT interrupts will not be enable until the
* MXT device has been opened (see mxt_open).
*/
return OK;
/* Error clean-up exits */
errout_with_hwinit:
kmm_free(priv->objtab);
kmm_free(priv->sample);
errout_with_irq:
MXT_DETACH(lower);
errout_with_priv:
sem_destroy(&priv->devsem);
sem_destroy(&priv->waitsem);
kmm_free(priv);
return ret;
}
