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incubator-nuttx/drivers/input/max11802.c

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/****************************************************************************
* drivers/input/max11802.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/* References:
* "Low-Power, Ultra-Small Resistive Touch-Screen Controllers
* with I2C/SPI Interface" Maxim IC, Rev 3, 10/2010
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <poll.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/wdog.h>
#include <nuttx/kmalloc.h>
#include <nuttx/wqueue.h>
#include <nuttx/fs/fs.h>
#include <nuttx/spi/spi.h>
#include <nuttx/random.h>
#include <nuttx/input/touchscreen.h>
#include <nuttx/input/max11802.h>
#include "max11802.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* This is a value for the threshold that guarantees a big difference on the
* first pendown (but can't overflow).
*/
#define INVALID_THRESHOLD 0x1000
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Low-level SPI helpers */
static void max11802_lock(FAR struct spi_dev_s *spi);
static void max11802_unlock(FAR struct spi_dev_s *spi);
static uint16_t max11802_sendcmd(FAR struct max11802_dev_s *priv,
uint8_t cmd, int *tags);
/* Interrupts and data sampling */
static void max11802_notify(FAR struct max11802_dev_s *priv);
static int max11802_sample(FAR struct max11802_dev_s *priv,
FAR struct max11802_sample_s *sample);
static int max11802_waitsample(FAR struct max11802_dev_s *priv,
FAR struct max11802_sample_s *sample);
static void max11802_worker(FAR void *arg);
static int max11802_interrupt(int irq, FAR void *context, FAR void *arg);
/* Character driver methods */
static int max11802_open(FAR struct file *filep);
static int max11802_close(FAR struct file *filep);
static ssize_t max11802_read(FAR struct file *filep, FAR char *buffer,
size_t len);
static int max11802_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
static int max11802_poll(FAR struct file *filep, struct pollfd *fds,
bool setup);
/****************************************************************************
* Private Data
****************************************************************************/
/* This the vtable that supports the character driver interface */
static const struct file_operations g_max11802_fops =
{
max11802_open, /* open */
max11802_close, /* close */
max11802_read, /* read */
NULL, /* write */
NULL, /* seek */
max11802_ioctl, /* ioctl */
NULL, /* mmap */
NULL, /* truncate */
max11802_poll /* poll */
};
/* If only a single MAX11802 device is supported, then the driver state
* structure may as well be pre-allocated.
*/
#ifndef CONFIG_MAX11802_MULTIPLE
static struct max11802_dev_s g_max11802;
/* Otherwise, we will need to maintain allocated driver instances in a list */
#else
static struct max11802_dev_s *g_max11802list;
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: max11802_lock
*
* Description:
* Lock the SPI bus and re-configure as necessary. This function must be
* to assure: (1) exclusive access to the SPI bus, and (2) to assure that
* the shared bus is properly configured for the touchscreen controller.
*
* Input Parameters:
* spi - Reference to the SPI driver structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static void max11802_lock(FAR struct spi_dev_s *spi)
{
/* Lock the SPI bus because there are multiple devices competing for the
* SPI bus
*/
SPI_LOCK(spi, true);
/* We have the lock. Now make sure that the SPI bus is configured for the
* MAX11802 (it might have gotten configured for a different device while
* unlocked)
*/
SPI_SETMODE(spi, CONFIG_MAX11802_SPIMODE);
SPI_SETBITS(spi, 8);
SPI_HWFEATURES(spi, 0);
SPI_SETFREQUENCY(spi, CONFIG_MAX11802_FREQUENCY);
}
/****************************************************************************
* Name: max11802_unlock
*
* Description:
* Un-lock the SPI bus after each transfer, possibly losing the current
* configuration if we are sharing the SPI bus with other devices
*
* Input Parameters:
* spi - Reference to the SPI driver structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
static void max11802_unlock(FAR struct spi_dev_s *spi)
{
/* Relinquish the SPI bus. */
SPI_LOCK(spi, false);
}
/****************************************************************************
* Name: max11802_sendcmd
****************************************************************************/
static uint16_t max11802_sendcmd(FAR struct max11802_dev_s *priv,
uint8_t cmd, int *tags)
{
uint8_t buffer[2];
uint16_t result;
/* Select the MAX11802 */
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), true);
/* Send the command */
SPI_SEND(priv->spi, cmd);
/* Read the data */
SPI_RECVBLOCK(priv->spi, buffer, 2);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), false);
result = ((uint16_t)buffer[0] << 8) | (uint16_t)buffer[1];
*tags = result & 0xf;
result >>= 4; /* Get rid of tags */
iinfo("cmd:%02x response:%04x\n", cmd, result);
return result;
}
/****************************************************************************
* Name: max11802_notify
****************************************************************************/
static void max11802_notify(FAR struct max11802_dev_s *priv)
{
/* If there are threads waiting on poll() for MAX11802 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.
*/
poll_notify(priv->fds, CONFIG_MAX11802_NPOLLWAITERS, POLLIN);
/* 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 sample
* is no longer available.
*/
nxsem_post(&priv->waitsem);
}
}
/****************************************************************************
* Name: max11802_sample
****************************************************************************/
static int max11802_sample(FAR struct max11802_dev_s *priv,
FAR struct max11802_sample_s *sample)
{
irqstate_t flags;
int ret = -EAGAIN;
/* 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.
*/
flags = enter_critical_section();
/* Is there new MAX11802 sample data available? */
if (priv->penchange)
{
/* Yes.. the state has changed in some way. Return a copy of the
* sampled data.
*/
memcpy(sample, &priv->sample, sizeof(struct max11802_sample_s));
/* Now manage state transitions */
if (sample->contact == CONTACT_UP)
{
/* Next.. no contact. Increment the ID so that next contact ID
* will be unique. X/Y positions are no longer valid.
*/
priv->sample.contact = CONTACT_NONE;
priv->sample.valid = false;
priv->id++;
}
else if (sample->contact == CONTACT_DOWN)
{
/* First report -- next report will be a movement */
priv->sample.contact = CONTACT_MOVE;
}
priv->penchange = false;
ret = OK;
}
leave_critical_section(flags);
return ret;
}
/****************************************************************************
* Name: max11802_waitsample
****************************************************************************/
static int max11802_waitsample(FAR struct max11802_dev_s *priv,
FAR struct max11802_sample_s *sample)
{
irqstate_t flags;
int ret;
/* 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.
*
* In addition, we will also disable pre-emption to prevent other threads
* from getting control while we muck with the semaphores.
*/
flags = enter_critical_section();
/* 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.
*/
nxmutex_unlock(&priv->devlock);
/* Try to get the a sample... if we cannot, then wait on the semaphore
* that is posted when new sample data is available.
*/
while (max11802_sample(priv, sample) < 0)
{
/* Wait for a change in the MAX11802 state */
iinfo("Waiting..\n");
priv->nwaiters++;
ret = nxsem_wait(&priv->waitsem);
priv->nwaiters--;
if (ret < 0)
{
ierr("ERROR: nxsem_wait: %d\n", ret);
goto errout;
}
}
iinfo("Sampled\n");
/* 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 = nxmutex_lock(&priv->devlock);
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.
*/
leave_critical_section(flags);
return ret;
}
/****************************************************************************
* Name: max11802_schedule
****************************************************************************/
static int max11802_schedule(FAR struct max11802_dev_s *priv)
{
FAR struct max11802_config_s *config;
int ret;
/* Get a pointer the callbacks for convenience (and so the code is not so
* ugly).
*/
config = priv->config;
DEBUGASSERT(config != NULL);
/* Disable further interrupts. MAX11802 interrupts will be re-enabled
* after the worker thread executes.
*/
config->enable(config, false);
/* Disable the watchdog timer. It will be re-enabled in the worker thread
* while the pen remains down.
*/
wd_cancel(&priv->wdog);
/* Transfer processing to the worker thread. Since MAX11802 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, max11802_worker, priv, 0);
if (ret != 0)
{
ierr("ERROR: Failed to queue work: %d\n", ret);
}
return OK;
}
/****************************************************************************
* Name: max11802_wdog
****************************************************************************/
static void max11802_wdog(wdparm_t arg)
{
FAR struct max11802_dev_s *priv =
(FAR struct max11802_dev_s *)arg;
max11802_schedule(priv);
}
/****************************************************************************
* Name: max11802_worker
****************************************************************************/
static void max11802_worker(FAR void *arg)
{
FAR struct max11802_dev_s *priv = (FAR struct max11802_dev_s *)arg;
FAR struct max11802_config_s *config;
uint16_t x;
uint16_t y;
uint16_t xdiff;
uint16_t ydiff;
bool pendown;
int tags;
int tags2;
DEBUGASSERT(priv != NULL);
/* Get a pointer the callbacks for convenience (and so the code is not so
* ugly).
*/
config = priv->config;
DEBUGASSERT(config != NULL);
/* Disable the watchdog timer. This is safe because it is started only
* by this function and this function is serialized on the worker thread.
*/
wd_cancel(&priv->wdog);
/* Lock the SPI bus so that we have exclusive access */
max11802_lock(priv->spi);
/* Start coordinate measurement */
max11802_sendcmd(priv, MAX11802_CMD_MEASUREXY, &tags);
/* Get exclusive access to the driver data structure */
nxmutex_lock(&priv->devlock);
/* Check for pen up or down by reading the PENIRQ GPIO. */
pendown = config->pendown(config);
/* Handle the change from pen down to pen up */
if (pendown)
{
iinfo("\nPD\n");
}
else
{
iinfo("\nPU\n");
}
if (!pendown)
{
/* The pen is up.. reset thresholding variables. */
priv->threshx = INVALID_THRESHOLD;
priv->threshy = INVALID_THRESHOLD;
/* Ignore the interrupt if the pen was already up (CONTACT_NONE ==
* pen up and already reported; CONTACT_UP == pen up, but not
* reported).
*/
iinfo("\nPC%d\n", priv->sample.contact);
if (priv->sample.contact == CONTACT_NONE ||
priv->sample.contact == CONTACT_UP)
{
goto ignored;
}
/* The pen is up. NOTE: We know from a previous test, that this is a
* loss of contact condition. This will be changed to CONTACT_NONE
* after the loss of contact is sampled.
*/
priv->sample.contact = CONTACT_UP;
}
/* It is a pen down event. If the last loss-of-contact event has not been
* processed yet, then we have to ignore the pen down event (or else it
* will look like a drag event)
*/
else if (priv->sample.contact == CONTACT_UP)
{
/* If we have not yet processed the last pen up event, then we
* cannot handle this pen down event. We will have to discard it.
* That should be okay because we will set the timer to sample
* again later.
*/
iinfo("Previous pen up event still in buffer\n");
max11802_notify(priv);
wd_start(&priv->wdog, MAX11802_WDOG_DELAY,
max11802_wdog, (wdparm_t)priv);
goto ignored;
}
else
{
/* Wait for data ready
*
* Note: MAX11802 signals the readiness of the results using
* the lowest 4 bits of the result. However these are the
* last bits to be read out of the device. It appears that
* the hardware value can change in the middle of the readout,
* causing the upper bits to be still invalid even though lower
* bits indicate valid result.
*
* We work around this by reading the registers once more after
* the tags indicate they are ready.
*/
int readycount = 0;
do
{
#ifdef CONFIG_MAX11802_SWAPXY
x = max11802_sendcmd(priv, MAX11802_CMD_YPOSITION, &tags);
y = max11802_sendcmd(priv, MAX11802_CMD_XPOSITION, &tags2);
#else
x = max11802_sendcmd(priv, MAX11802_CMD_XPOSITION, &tags);
y = max11802_sendcmd(priv, MAX11802_CMD_YPOSITION, &tags2);
#endif
if (tags != 0xf && tags2 != 0xf)
{
readycount++;
}
}
while (readycount < 2);
add_ui_randomness((x << 16) | y);
/* Continue to sample the position while the pen is down */
wd_start(&priv->wdog, MAX11802_WDOG_DELAY,
max11802_wdog, (wdparm_t)priv);
/* Check if data is valid */
if ((tags & 0x03) != 0)
{
iinfo("Touch ended before measurement\n");
goto ignored;
}
/* Perform a thresholding operation so that the results will be more
* stable. If the difference from the last sample is small, then
* ignore the event.
*
* REVISIT: Should a large change in pressure also generate a event?
*/
xdiff = x > priv->threshx ? (x - priv->threshx) : (priv->threshx - x);
ydiff = y > priv->threshy ? (y - priv->threshy) : (priv->threshy - y);
/* Check the thresholds. Bail if there is no significant
* difference.
*/
if (xdiff < CONFIG_MAX11802_THRESHX && ydiff < CONFIG_MAX11802_THRESHY)
{
/* Little or no change in either direction ... don't report
* anything.
*/
goto ignored;
}
/* When we see a big difference, snap to the new x/y thresholds */
priv->threshx = x;
priv->threshy = y;
/* Update the x/y position in the sample data */
priv->sample.x = priv->threshx;
priv->sample.y = priv->threshy;
/* The X/Y positional data is now valid */
priv->sample.valid = true;
/* If this is the first (acknowledged) pen down report, then report
* this as the first contact. If contact == CONTACT_DOWN, it will be
* set to set to CONTACT_MOVE after the contact is first sampled.
*/
if (priv->sample.contact != CONTACT_MOVE)
{
/* First contact */
priv->sample.contact = CONTACT_DOWN;
}
}
/* Indicate the availability of new sample data for this ID */
priv->sample.id = priv->id;
priv->penchange = true;
/* Notify any waiters that new MAX11802 data is available */
max11802_notify(priv);
ignored:
config->enable(config, true);
/* Release our lock on the state structure and unlock the SPI bus */
nxmutex_unlock(&priv->devlock);
max11802_unlock(priv->spi);
}
/****************************************************************************
* Name: max11802_interrupt
****************************************************************************/
static int max11802_interrupt(int irq, FAR void *context, FAR void *arg)
{
FAR struct max11802_dev_s *priv;
FAR struct max11802_config_s *config;
int ret;
/* Which MAX11802 device caused the interrupt? */
#ifndef CONFIG_MAX11802_MULTIPLE
priv = &g_max11802;
#else
for (priv = g_max11802list;
priv && priv->configs->irq != irq;
priv = priv->flink);
DEBUGASSERT(priv != NULL);
#endif
/* Get a pointer the callbacks for convenience (and so the code is not so
* ugly).
*/
config = priv->config;
DEBUGASSERT(config != NULL);
/* Schedule sampling to occur on the worker thread */
ret = max11802_schedule(priv);
/* Clear any pending interrupts and return success */
config->clear(config);
return ret;
}
/****************************************************************************
* Name: max11802_open
****************************************************************************/
static int max11802_open(FAR struct file *filep)
{
#ifdef CONFIG_MAX11802_REFCNT
FAR struct inode *inode;
FAR struct max11802_dev_s *priv;
uint8_t tmp;
int ret;
iinfo("Opening\n");
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Get exclusive access to the driver data structure */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
/* Increment the reference count */
tmp = priv->crefs + 1;
if (tmp == 0)
{
/* More than 255 opens; uint8_t overflows to zero */
ret = -EMFILE;
goto errout_with_lock;
}
/* When the reference increments to 1, this is the first open event
* on the driver.. and an opportunity to do any one-time initialization.
*/
/* Save the new open count on success */
priv->crefs = tmp;
errout_with_lock:
nxmutex_unlock(&priv->devlock);
return ret;
#else
iinfo("Opening\n");
return OK;
#endif
}
/****************************************************************************
* Name: max11802_close
****************************************************************************/
static int max11802_close(FAR struct file *filep)
{
#ifdef CONFIG_MAX11802_REFCNT
FAR struct inode *inode;
FAR struct max11802_dev_s *priv;
int ret;
iinfo("Closing\n");
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Get exclusive access to the driver data structure */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
/* 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)
{
priv->crefs--;
}
nxmutex_unlock(&priv->devlock);
#endif
iinfo("Closing\n");
return OK;
}
/****************************************************************************
* Name: max11802_read
****************************************************************************/
static ssize_t max11802_read(FAR struct file *filep, FAR char *buffer,
size_t len)
{
FAR struct inode *inode;
FAR struct max11802_dev_s *priv;
FAR struct touch_sample_s *report;
struct max11802_sample_s sample;
int ret;
iinfo("buffer:%p len:%d\n", buffer, len);
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = 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?
*/
ierr("ERROR: Unsupported read size: %d\n", len);
return -ENOSYS;
}
/* Get exclusive access to the driver data structure */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
ierr("ERROR: nxsem_wait: %d\n", ret);
return ret;
}
/* Try to read sample data. */
ret = max11802_sample(priv, &sample);
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.
*/
iinfo("Sample data is not available\n");
if (filep->f_oflags & O_NONBLOCK)
{
ret = -EAGAIN;
goto errout;
}
/* Wait for sample data */
ret = max11802_waitsample(priv, &sample);
if (ret < 0)
{
/* We might have been awakened by a signal */
ierr("ERROR: max11802_waitsample: %d\n", ret);
goto errout;
}
}
/* In any event, we now have sampled MAX11802 data that we can report
* to the caller.
*/
report = (FAR struct touch_sample_s *)buffer;
memset(report, 0, SIZEOF_TOUCH_SAMPLE_S(1));
report->npoints = 1;
report->point[0].id = sample.id;
report->point[0].x = sample.x;
report->point[0].y = sample.y;
/* Report the appropriate flags */
if (sample.contact == CONTACT_UP)
{
/* Pen is now up. 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)
{
report->point[0].flags = TOUCH_UP | TOUCH_ID_VALID |
TOUCH_POS_VALID;
}
else
{
report->point[0].flags = TOUCH_UP | TOUCH_ID_VALID;
}
}
else if (sample.contact == CONTACT_DOWN)
{
/* First contact */
report->point[0].flags = TOUCH_DOWN | TOUCH_ID_VALID |
TOUCH_POS_VALID;
}
else /* if (sample->contact == CONTACT_MOVE) */
{
/* Movement of the same contact */
report->point[0].flags = TOUCH_MOVE | TOUCH_ID_VALID |
TOUCH_POS_VALID;
}
iinfo(" id: %d\n", report->point[0].id);
iinfo(" flags: %02x\n", report->point[0].flags);
iinfo(" x: %d\n", report->point[0].x);
iinfo(" y: %d\n", report->point[0].y);
ret = SIZEOF_TOUCH_SAMPLE_S(1);
errout:
nxmutex_unlock(&priv->devlock);
iinfo("Returning: %d\n", ret);
return ret;
}
/****************************************************************************
* Name: max11802_ioctl
****************************************************************************/
static int max11802_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode;
FAR struct max11802_dev_s *priv;
int ret;
iinfo("cmd: %d arg: %ld\n", cmd, arg);
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Get exclusive access to the driver data structure */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
/* 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->config != NULL && ptr != NULL);
priv->config->frequency = SPI_SETFREQUENCY(priv->spi, *ptr);
}
break;
case TSIOC_GETFREQUENCY: /* arg: Pointer to uint32_t frequency value */
{
FAR uint32_t *ptr = (FAR uint32_t *)((uintptr_t)arg);
DEBUGASSERT(priv->config != NULL && ptr != NULL);
*ptr = priv->config->frequency;
}
break;
default:
ret = -ENOTTY;
break;
}
nxmutex_unlock(&priv->devlock);
return ret;
}
/****************************************************************************
* Name: max11802_poll
****************************************************************************/
static int max11802_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup)
{
FAR struct inode *inode;
FAR struct max11802_dev_s *priv;
int ret;
int i;
iinfo("setup: %d\n", (int)setup);
DEBUGASSERT(fds);
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Are we setting up the poll? Or tearing it down? */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
if (setup)
{
/* Ignore waits that do not include POLLIN */
if ((fds->events & POLLIN) == 0)
{
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_MAX11802_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_MAX11802_NPOLLWAITERS)
{
fds->priv = NULL;
ret = -EBUSY;
goto errout;
}
/* Should we immediately notify on any of the requested events? */
if (priv->penchange)
{
max11802_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:
nxmutex_unlock(&priv->devlock);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: max11802_register
*
* Description:
* Configure the MAX11802 to use the provided SPI device instance. This
* will register the driver as /dev/inputN where N is the minor device
* number
*
* Input Parameters:
* dev - An SPI driver instance
* config - 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 max11802_register(FAR struct spi_dev_s *spi,
FAR struct max11802_config_s *config, int minor)
{
FAR struct max11802_dev_s *priv;
char devname[DEV_NAMELEN];
#ifdef CONFIG_MAX11802_MULTIPLE
irqstate_t flags;
#endif
int ret;
iinfo("spi: %p minor: %d\n", spi, minor);
/* Debug-only sanity checks */
DEBUGASSERT(spi != NULL && config != NULL && minor >= 0 && minor < 100);
/* Create and initialize a MAX11802 device driver instance */
#ifndef CONFIG_MAX11802_MULTIPLE
priv = &g_max11802;
#else
priv = (FAR struct max11802_dev_s *)
kmm_malloc(sizeof(struct max11802_dev_s));
if (!priv)
{
ierr("ERROR: kmm_malloc(%d) failed\n", sizeof(struct max11802_dev_s));
return -ENOMEM;
}
#endif
/* Initialize the MAX11802 device driver instance */
memset(priv, 0, sizeof(struct max11802_dev_s));
priv->spi = spi; /* Save the SPI device handle */
priv->config = config; /* Save the board configuration */
priv->threshx = INVALID_THRESHOLD; /* Initialize thresholding logic */
priv->threshy = INVALID_THRESHOLD; /* Initialize thresholding logic */
/* Initialize mutex & semaphores */
nxmutex_init(&priv->devlock); /* Initialize device structure mutex */
nxsem_init(&priv->waitsem, 0, 0); /* Initialize pen event wait semaphore */
/* Make sure that interrupts are disabled */
config->clear(config);
config->enable(config, false);
/* Attach the interrupt handler */
ret = config->attach(config, max11802_interrupt);
if (ret < 0)
{
ierr("ERROR: Failed to attach interrupt\n");
goto errout_with_priv;
}
iinfo("Mode: %d Bits: 8 Frequency: %d\n",
CONFIG_MAX11802_SPIMODE, CONFIG_MAX11802_FREQUENCY);
/* Lock the SPI bus so that we have exclusive access */
max11802_lock(spi);
/* Configure MAX11802 registers */
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), true);
SPI_SEND(priv->spi, MAX11802_CMD_MODE_WR);
SPI_SEND(priv->spi, MAX11802_MODE);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), false);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), true);
SPI_SEND(priv->spi, MAX11802_CMD_AVG_WR);
SPI_SEND(priv->spi, MAX11802_AVG);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), false);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), true);
SPI_SEND(priv->spi, MAX11802_CMD_SAMPLE_WR);
SPI_SEND(priv->spi, MAX11802_SAMPLE);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), false);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), true);
SPI_SEND(priv->spi, MAX11802_CMD_TIMING_WR);
SPI_SEND(priv->spi, MAX11802_TIMING);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), false);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), true);
SPI_SEND(priv->spi, MAX11802_CMD_DELAY_WR);
SPI_SEND(priv->spi, MAX11802_DELAY);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), false);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), true);
SPI_SEND(priv->spi, MAX11802_CMD_PULL_WR);
SPI_SEND(priv->spi, MAX11802_PULL);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), false);
/* Test that the device access was successful. */
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), true);
SPI_SEND(priv->spi, MAX11802_CMD_MODE_RD);
ret = SPI_SEND(priv->spi, 0);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN(0), false);
/* Unlock the bus */
max11802_unlock(spi);
if (ret != MAX11802_MODE)
{
ierr("ERROR: max11802 mode readback failed: %02x\n", ret);
goto errout_with_priv;
}
/* Register the device as an input device */
snprintf(devname, sizeof(devname), DEV_FORMAT, minor);
iinfo("Registering %s\n", devname);
ret = register_driver(devname, &g_max11802_fops, 0666, priv);
if (ret < 0)
{
ierr("ERROR: register_driver() failed: %d\n", ret);
goto errout_with_priv;
}
/* If multiple MAX11802 devices are supported, then we will need to add
* this new instance to a list of device instances so that it can be
* found by the interrupt handler based on the received IRQ number.
*/
#ifdef CONFIG_MAX11802_MULTIPLE
flags = enter_critical_section();
priv->flink = g_max11802list;
g_max11802list = priv;
leave_critical_section(flags);
#endif
/* Schedule work to perform the initial sampling and to set the data
* availability conditions.
*/
ret = work_queue(HPWORK, &priv->work, max11802_worker, priv, 0);
if (ret != 0)
{
ierr("ERROR: Failed to queue work: %d\n", ret);
goto errout_with_priv;
}
/* And return success (?) */
return OK;
errout_with_priv:
nxmutex_destroy(&priv->devlock);
nxsem_destroy(&priv->waitsem);
#ifdef CONFIG_MAX11802_MULTIPLE
kmm_free(priv);
#endif
return ret;
}
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