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apache / nuttx / 350fa87fea6df20a7c470330d88222cee8cd6df0 / . / drivers / input / ads7843e.c
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/****************************************************************************
* drivers/input/ads7843e.c
*
* Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
* Authors: Gregory Nutt <gnutt@nuttx.org>
* Diego Sanchez <dsanchez@nx-engineering.com>
*
* References:
* "Touch Screen Controller, ADS7843," Burr-Brown Products from Texas
* Instruments, SBAS090B, September 2000, Revised May 2002"
*
* See also:
* "Low Voltage I/O Touch Screen Controller, TSC2046," Burr-Brown Products
* from Texas Instruments, SBAS265F, October 2002, Revised August 2007.
*
* "XPT2046 Data Sheet," Shenzhen XPTek Technology Co., Ltd, 2007
*
* 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>
#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 <wdog.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/spi/spi.h>
#include <nuttx/wqueue.h>
#include <nuttx/input/touchscreen.h>
#include <nuttx/input/ads7843e.h>
#include "ads7843e.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 */
#ifdef CONFIG_SPI_OWNBUS
static inline void ads7843e_configspi(FAR struct spi_dev_s *spi);
# define ads7843e_lock(spi)
# define ads7843e_unlock(spi)
#else
# define ads7843e_configspi(spi);
static void ads7843e_lock(FAR struct spi_dev_s *spi);
static void ads7843e_unlock(FAR struct spi_dev_s *spi);
#endif
static uint16_t ads7843e_sendcmd(FAR struct ads7843e_dev_s *priv, uint8_t cmd);
/* Interrupts and data sampling */
static void ads7843e_notify(FAR struct ads7843e_dev_s *priv);
static int ads7843e_sample(FAR struct ads7843e_dev_s *priv,
FAR struct ads7843e_sample_s *sample);
static int ads7843e_waitsample(FAR struct ads7843e_dev_s *priv,
FAR struct ads7843e_sample_s *sample);
static void ads7843e_worker(FAR void *arg);
static int ads7843e_interrupt(int irq, FAR void *context);
/* Character driver methods */
static int ads7843e_open(FAR struct file *filep);
static int ads7843e_close(FAR struct file *filep);
static ssize_t ads7843e_read(FAR struct file *filep, FAR char *buffer, size_t len);
static int ads7843e_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
#ifndef CONFIG_DISABLE_POLL
static int ads7843e_poll(FAR struct file *filep, struct pollfd *fds, bool setup);
#endif
/****************************************************************************
* Private Data
****************************************************************************/
/* This the vtable that supports the character driver interface */
static const struct file_operations ads7843e_fops =
{
ads7843e_open, /* open */
ads7843e_close, /* close */
ads7843e_read, /* read */
0, /* write */
0, /* seek */
ads7843e_ioctl /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, ads7843e_poll /* poll */
#endif
};
/* If only a single ADS7843E device is supported, then the driver state
* structure may as well be pre-allocated.
*/
#ifndef CONFIG_ADS7843E_MULTIPLE
static struct ads7843e_dev_s g_ads7843e;
/* Otherwise, we will need to maintain allocated driver instances in a list */
#else
static struct ads7843e_dev_s *g_ads7843elist;
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Function: ads7843e_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.
*
* Parameters:
* spi - Reference to the SPI driver structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
#ifndef CONFIG_SPI_OWNBUS
static void ads7843e_lock(FAR struct spi_dev_s *spi)
{
/* Lock the SPI bus because there are multiple devices competing for the
* SPI bus
*/
(void)SPI_LOCK(spi, true);
/* We have the lock. Now make sure that the SPI bus is configured for the
* ADS7843 (it might have gotten configured for a different device while
* unlocked)
*/
SPI_SELECT(spi, SPIDEV_TOUCHSCREEN, true);
SPI_SETMODE(spi, CONFIG_ADS7843E_SPIMODE);
SPI_SETBITS(spi, 8);
SPI_SETFREQUENCY(spi, CONFIG_ADS7843E_FREQUENCY);
SPI_SELECT(spi, SPIDEV_TOUCHSCREEN, false);
}
#endif
/****************************************************************************
* Function: ads7843e_unlock
*
* Description:
* If we are sharing the SPI bus with other devices (CONFIG_SPI_OWNBUS
* undefined) then we need to un-lock the SPI bus for each transfer,
* possibly losing the current configuration.
*
* Parameters:
* spi - Reference to the SPI driver structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
#ifndef CONFIG_SPI_OWNBUS
static void ads7843e_unlock(FAR struct spi_dev_s *spi)
{
/* Relinquish the SPI bus. */
(void)SPI_LOCK(spi, false);
}
#endif
/****************************************************************************
* Function: ads7843e_configspi
*
* Description:
* Configure the SPI for use with the ADS7843E. This function should be
* called once during touchscreen initialization to configure the SPI
* bus. Note that if CONFIG_SPI_OWNBUS is not defined, then this function
* does nothing.
*
* Parameters:
* spi - Reference to the SPI driver structure
*
* Returned Value:
* None
*
* Assumptions:
*
****************************************************************************/
#ifdef CONFIG_SPI_OWNBUS
static inline void ads7843e_configspi(FAR struct spi_dev_s *spi)
{
/* Configure SPI for the ADS7843. But only if we own the SPI bus. Otherwise, don't
* bother because it might change.
*/
SPI_SELECT(spi, SPIDEV_TOUCHSCREEN, true);
SPI_SETMODE(spi, CONFIG_ADS7843E_SPIMODE);
SPI_SETBITS(spi, 8);
SPI_SETFREQUENCY(spi, CONFIG_ADS7843E_FREQUENCY);
SPI_SELECT(spi, SPIDEV_TOUCHSCREEN, false);
}
#endif
/****************************************************************************
* Name: ads7843e_sendcmd
*
* Description.
* The command/data sequences is as follows:
*
* DCLK
* 1 2 3 4 5 6 7 8 1 2 3 4 ...
* S A2 A1 A0 MODE SER PD1 PD0
* DFR
* START CCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
* CMD
* Aquisition AAAAAAAAAAA
* TIME
* BUSY BBBBBBBB
* Reported
* 12-bit DDDDDDDDDDDD...
* response
*
* The BUSY output is high imedance when /CS is high. BUSY goes low when
* /CS goes low (within 200ns). BUSY goes high on the falling edge of the
* 8th clock (within 200ns); BUSY goes low again after the falling edge of
* first clock of the 12-bit data read, at the leading edge of the MS bit
* 11 of the 12-bit data response.
*
* The acquisition time is 3 clock cycles and so should be complete at the
* end of the command transfer. Other places say that this time is
* nominally 2 microseconds.
*
* So what good is this BUSY? Many boards do not even bother to bring it
* to the MCU. Busy will stick high until we read the data so you cannot
* wait on it before reading.
*
****************************************************************************/
static uint16_t ads7843e_sendcmd(FAR struct ads7843e_dev_s *priv, uint8_t cmd)
{
uint8_t buffer[2];
uint16_t result;
/* Select the ADS7843E */
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN, true);
/* Send the command */
(void)SPI_SEND(priv->spi, cmd);
/* Wait a tiny amount to make sure that the aquisition time is complete */
up_udelay(3); /* 3 microseconds */
/* Read the 12-bit data (LS 4 bits will be padded with zero) */
SPI_RECVBLOCK(priv->spi, buffer, 2);
SPI_SELECT(priv->spi, SPIDEV_TOUCHSCREEN, false);
result = ((uint16_t)buffer[0] << 8) | (uint16_t)buffer[1];
result = result >> 4;
ivdbg("cmd:%02x response:%04x\n", cmd, result);
return result;
}
/****************************************************************************
* Name: ads7843e_notify
****************************************************************************/
static void ads7843e_notify(FAR struct ads7843e_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 ADS7843E
* is no longer available.
*/
sem_post(&priv->waitsem);
}
/* If there are threads waiting on poll() for ADS7843E 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_ADS7843E_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: ads7843e_sample
****************************************************************************/
static int ads7843e_sample(FAR struct ads7843e_dev_s *priv,
FAR struct ads7843e_sample_s *sample)
{
irqstate_t flags;
int ret = -EAGAIN;
/* 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();
/* Is there new ADS7843E 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 ads7843e_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;
}
irqrestore(flags);
return ret;
}
/****************************************************************************
* Name: ads7843e_waitsample
****************************************************************************/
static int ads7843e_waitsample(FAR struct ads7843e_dev_s *priv,
FAR struct ads7843e_sample_s *sample)
{
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.
*
* In addition, we will also disable pre-emption to prevent other threads
* from getting control while we muck with the semaphores.
*/
sched_lock();
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 (ads7843e_sample(priv, sample) < 0)
{
/* Wait for a change in the ADS7843E state */
ivdbg("Waiting..\n");
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.
*/
idbg("sem_wait: %d\n", errno);
DEBUGASSERT(errno == EINTR);
ret = -EINTR;
goto errout;
}
}
ivdbg("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 = 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);
/* Restore pre-emption. We might get suspended here but that is okay
* because we already have our sample. Note: this means that if there
* were two threads reading from the ADS7843E for some reason, the data
* might be read out of order.
*/
sched_unlock();
return ret;
}
/****************************************************************************
* Name: ads7843e_schedule
****************************************************************************/
static int ads7843e_schedule(FAR struct ads7843e_dev_s *priv)
{
FAR struct ads7843e_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. ADS7843E 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 ADS7843E 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, ads7843e_worker, priv, 0);
if (ret != 0)
{
illdbg("Failed to queue work: %d\n", ret);
}
return OK;
}
/****************************************************************************
* Name: ads7843e_wdog
****************************************************************************/
static void ads7843e_wdog(int argc, uint32_t arg1, ...)
{
FAR struct ads7843e_dev_s *priv = (FAR struct ads7843e_dev_s *)((uintptr_t)arg1);
(void)ads7843e_schedule(priv);
}
/****************************************************************************
* Name: ads7843e_worker
****************************************************************************/
static void ads7843e_worker(FAR void *arg)
{
FAR struct ads7843e_dev_s *priv = (FAR struct ads7843e_dev_s *)arg;
FAR struct ads7843e_config_s *config;
uint16_t x;
uint16_t y;
uint16_t xdiff;
uint16_t ydiff;
bool pendown;
int ret;
ASSERT(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 */
ads7843e_lock(priv->spi);
/* Get exclusive access to the driver data structure */
do
{
ret = sem_wait(&priv->devsem);
/* This should only fail if the wait was canceled by an signal
* (and the worker thread will receive a lot of signals).
*/
DEBUGASSERT(ret == OK || errno == EINTR);
}
while (ret < 0);
/* 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)
{
/* 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)
*/
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 to sample again
* later.
*/
wd_start(priv->wdog, ADS7843E_WDOG_DELAY, ads7843e_wdog, 1, (uint32_t)priv);
goto ignored;
}
else
{
/* Handle pen down events. First, sample positional values. NOTE:
* that these commands have the side-effect of disabling the PENIRQ.
*/
#ifdef CONFIG_ADS7843E_SWAPXY
x = ads7843e_sendcmd(priv, ADS7843_CMD_YPOSITION);
y = ads7843e_sendcmd(priv, ADS7843_CMD_XPOSITION);
#else
x = ads7843e_sendcmd(priv, ADS7843_CMD_XPOSITION);
y = ads7843e_sendcmd(priv, ADS7843_CMD_YPOSITION);
#endif
/* 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);
/* Continue to sample the position while the pen is down */
wd_start(priv->wdog, ADS7843E_WDOG_DELAY, ads7843e_wdog, 1, (uint32_t)priv);
/* Check the thresholds. Bail if there is no significant difference */
if (xdiff < CONFIG_ADS7843E_THRESHX && ydiff < CONFIG_ADS7843E_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 ADS7843E data is available */
ads7843e_notify(priv);
/* Exit, re-enabling ADS7843E interrupts */
ignored:
/* Re-enable the PENIRQ interrupt at the ADS7843E */
(void)ads7843e_sendcmd(priv, ADS7843_CMD_ENABPENIRQ);
/* Re-enable the PENIRQ interrupt at the MCU's interrupt controller */
config->enable(config, true);
/* Release our lock on the state structure and unlock the SPI bus */
sem_post(&priv->devsem);
ads7843e_unlock(priv->spi);
}
/****************************************************************************
* Name: ads7843e_interrupt
****************************************************************************/
static int ads7843e_interrupt(int irq, FAR void *context)
{
FAR struct ads7843e_dev_s *priv;
FAR struct ads7843e_config_s *config;
int ret;
/* Which ADS7843E device caused the interrupt? */
#ifndef CONFIG_ADS7843E_MULTIPLE
priv = &g_ads7843e;
#else
for (priv = g_ads7843elist;
priv && priv->configs->irq != irq;
priv = priv->flink);
ASSERT(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 = ads7843e_schedule(priv);
/* Clear any pending interrupts and return success */
config->clear(config);
return ret;
}
/****************************************************************************
* Name: ads7843e_open
****************************************************************************/
static int ads7843e_open(FAR struct file *filep)
{
#ifdef CONFIG_ADS7843E_REFCNT
FAR struct inode *inode;
FAR struct ads7843e_dev_s *priv;
uint8_t tmp;
int ret;
ivdbg("Opening\n");
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct ads7843e_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 canceled 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 */
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.
*/
/* Save the new open count on success */
priv->crefs = tmp;
errout_with_sem:
sem_post(&priv->devsem);
return ret;
#else
ivdbg("Opening\n");
return OK;
#endif
}
/****************************************************************************
* Name: ads7843e_close
****************************************************************************/
static int ads7843e_close(FAR struct file *filep)
{
#ifdef CONFIG_ADS7843E_REFCNT
FAR struct inode *inode;
FAR struct ads7843e_dev_s *priv;
int ret;
ivdbg("Closing\n");
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct ads7843e_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 canceled 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)
{
priv->crefs--;
}
sem_post(&priv->devsem);
#endif
ivdbg("Closing\n");
return OK;
}
/****************************************************************************
* Name: ads7843e_read
****************************************************************************/
static ssize_t ads7843e_read(FAR struct file *filep, FAR char *buffer, size_t len)
{
FAR struct inode *inode;
FAR struct ads7843e_dev_s *priv;
FAR struct touch_sample_s *report;
struct ads7843e_sample_s sample;
int ret;
ivdbg("buffer:%p len:%d\n", buffer, len);
DEBUGASSERT(filep);
inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
priv = (FAR struct ads7843e_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?
*/
idbg("Unsupported read size: %d\n", len);
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 canceled by an signal */
idbg("sem_wait: %d\n", errno);
DEBUGASSERT(errno == EINTR);
return -EINTR;
}
/* Try to read sample data. */
ret = ads7843e_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.
*/
ivdbg("Sample data is not available\n");
if (filep->f_oflags & O_NONBLOCK)
{
ret = -EAGAIN;
goto errout;
}
/* Wait for sample data */
ret = ads7843e_waitsample(priv, &sample);
if (ret < 0)
{
/* We might have been awakened by a signal */
idbg("ads7843e_waitsample: %d\n", ret);
goto errout;
}
}
/* In any event, we now have sampled ADS7843E 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;
}
ivdbg(" id: %d\n", report->point[0].id);
ivdbg(" flags: %02x\n", report->point[0].flags);
ivdbg(" x: %d\n", report->point[0].x);
ivdbg(" y: %d\n", report->point[0].y);
ret = SIZEOF_TOUCH_SAMPLE_S(1);
errout:
sem_post(&priv->devsem);
ivdbg("Returning: %d\n", ret);
return ret;
}
/****************************************************************************
* Name:ads7843e_ioctl
****************************************************************************/
static int ads7843e_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode;
FAR struct ads7843e_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 ads7843e_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 canceled 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->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;
}
sem_post(&priv->devsem);
return ret;
}
/****************************************************************************
* Name: ads7843e_poll
****************************************************************************/
#ifndef CONFIG_DISABLE_POLL
static int ads7843e_poll(FAR struct file *filep, FAR struct pollfd *fds,
bool setup)
{
FAR struct inode *inode;
FAR struct ads7843e_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 ads7843e_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 canceled by an signal */
DEBUGASSERT(errno == EINTR);
return -EINTR;
}
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_ADS7843E_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_ADS7843E_NPOLLWAITERS)
{
fds->priv = NULL;
ret = -EBUSY;
goto errout;
}
/* Should we immediately notify on any of the requested events? */
if (priv->penchange)
{
ads7843e_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
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ads7843e_register
*
* Description:
* Configure the ADS7843E 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 ads7843e_register(FAR struct spi_dev_s *spi,
FAR struct ads7843e_config_s *config, int minor)
{
FAR struct ads7843e_dev_s *priv;
char devname[DEV_NAMELEN];
#ifdef CONFIG_ADS7843E_MULTIPLE
irqstate_t flags;
#endif
int ret;
ivdbg("spi: %p minor: %d\n", spi, minor);
/* Debug-only sanity checks */
DEBUGASSERT(spi != NULL && config != NULL && minor >= 0 && minor < 100);
/* Create and initialize a ADS7843E device driver instance */
#ifndef CONFIG_ADS7843E_MULTIPLE
priv = &g_ads7843e;
#else
priv = (FAR struct ads7843e_dev_s *)kmalloc(sizeof(struct ads7843e_dev_s));
if (!priv)
{
idbg("kmalloc(%d) failed\n", sizeof(struct ads7843e_dev_s));
return -ENOMEM;
}
#endif
/* Initialize the ADS7843E device driver instance */
memset(priv, 0, sizeof(struct ads7843e_dev_s));
priv->spi = spi; /* Save the SPI device handle */
priv->config = config; /* Save the board configuration */
priv->wdog = wd_create(); /* Create a watchdog timer */
priv->threshx = INVALID_THRESHOLD; /* Initialize thresholding logic */
priv->threshy = INVALID_THRESHOLD; /* Initialize thresholding logic */
sem_init(&priv->devsem, 0, 1); /* Initialize device structure semaphore */
sem_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, ads7843e_interrupt);
if (ret < 0)
{
idbg("Failed to attach interrupt\n");
goto errout_with_priv;
}
idbg("Mode: %d Bits: 8 Frequency: %d\n",
CONFIG_ADS7843E_SPIMODE, CONFIG_ADS7843E_FREQUENCY);
/* Lock the SPI bus so that we have exclusive access */
ads7843e_lock(spi);
/* Configure the SPI interface */
ads7843e_configspi(spi);
/* Enable the PEN IRQ */
ads7843e_sendcmd(priv, ADS7843_CMD_ENABPENIRQ);
/* Unlock the bus */
ads7843e_unlock(spi);
/* Register the device as an input device */
(void)snprintf(devname, DEV_NAMELEN, DEV_FORMAT, minor);
ivdbg("Registering %s\n", devname);
ret = register_driver(devname, &ads7843e_fops, 0666, priv);
if (ret < 0)
{
idbg("register_driver() failed: %d\n", ret);
goto errout_with_priv;
}
/* If multiple ADS7843E 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 recieved IRQ number.
*/
#ifdef CONFIG_ADS7843E_MULTIPLE
priv->flink = g_ads7843elist;
g_ads7843elist = priv;
irqrestore(flags);
#endif
/* Schedule work to perform the initial sampling and to set the data
* availability conditions.
*/
ret = work_queue(HPWORK, &priv->work, ads7843e_worker, priv, 0);
if (ret != 0)
{
idbg("Failed to queue work: %d\n", ret);
goto errout_with_priv;
}
/* And return success (?) */
return OK;
errout_with_priv:
sem_destroy(&priv->devsem);
#ifdef CONFIG_ADS7843E_MULTIPLE
kfree(priv);
#endif
return ret;
}