/**************************************************************************** * drivers/input/ads7843e.c * * Copyright (C) 2011-2012 Gregory Nutt. All rights reserved. * Authors: Gregory Nutt * Diego Sanchez * * References: * "Touch Screen Controller, ADS7843," Burr-Brown Products from Texas * Instruments, SBAS090B, September 2000, Revised May 2002" * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ads7843e.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /**************************************************************************** * Private Types ****************************************************************************/ /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /* Low-level SPI helpers */ static inline void ads7843e_configspi(FAR struct spi_dev_s *spi); #ifdef CONFIG_SPI_OWNBUS static inline void ads7843e_select(FAR struct spi_dev_s *spi); static inline void ads7843e_deselect(FAR struct spi_dev_s *spi); #else static void ads7843e_select(FAR struct spi_dev_s *spi); static void ads7843e_deselect(FAR struct spi_dev_s *spi); #endif static inline void ads7843e_waitbusy(FAR struct ads7843e_dev_s *priv); 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 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_select * * Description: * Select the SPI, locking and re-configuring if necessary. This function * must be called before initiating any sequence of SPI operations. If we * are sharing the SPI bus with other devices (CONFIG_SPI_OWNBUS undefined) * then we need to lock and configure the SPI bus for each transfer. * * Parameters: * spi - Reference to the SPI driver structure * * Returned Value: * None * * Assumptions: * ****************************************************************************/ #ifdef CONFIG_SPI_OWNBUS static inline void ads7843e_select(FAR struct spi_dev_s *spi) { /* We own the SPI bus, so just select the chip */ SPI_SELECT(spi, SPIDEV_TOUCHSCREEN, true); } #else static void ads7843e_select(FAR struct spi_dev_s *spi) { /* Select ADS7843 chip (locking the SPI bus in case there are multiple * devices competing for the SPI bus */ SPI_LOCK(spi, true); SPI_SELECT(spi, SPIDEV_TOUCHSCREEN, true); /* Now make sure that the SPI bus is configured for the ADS7843 (it * might have gotten configured for a different device while unlocked) */ SPI_SETMODE(spi, CONFIG_ADS7843E_SPIMODE); SPI_SETBITS(spi, 8); SPI_SETFREQUENCY(spi, CONFIG_ADS7843E_FREQUENCY); } #endif /**************************************************************************** * Function: ads7843e_deselect * * Description: * De-select the SPI, unlocking as necessary. This function must be * after completing a sequence of SPI operations. 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: * ****************************************************************************/ #ifdef CONFIG_SPI_OWNBUS static inline void ads7843e_deselect(FAR struct spi_dev_s *spi) { /* We own the SPI bus, so just de-select the chip */ SPI_SELECT(spi, SPIDEV_TOUCHSCREEN, false); } #else static void ads7843e_deselect(FAR struct spi_dev_s *spi) { /* De-select ADS7843 chip and relinquish the SPI bus. */ SPI_SELECT(spi, SPIDEV_TOUCHSCREEN, false); 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: * ****************************************************************************/ static inline void ads7843e_configspi(FAR struct spi_dev_s *spi) { idbg("Mode: %d Bits: 8 Frequency: %d\n", CONFIG_ADS7843E_SPIMODE, CONFIG_ADS7843E_FREQUENCY); /* Configure SPI for the ADS7843. But only if we own the SPI bus. Otherwise, don't * bother because it might change. */ #ifdef CONFIG_SPI_OWNBUS 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_waitbusy ****************************************************************************/ static inline void ads7843e_waitbusy(FAR struct ads7843e_dev_s *priv) { while (priv->config->busy(priv->config)); } /**************************************************************************** * Name: ads7843e_sendcmd ****************************************************************************/ static uint16_t ads7843e_sendcmd(FAR struct ads7843e_dev_s *priv, uint8_t cmd) { uint8_t buffer[2]; uint16_t result; /* Select the ADS7843E */ ads7843e_select(priv->spi); /* Send the command */ (void)SPI_SEND(priv->spi, cmd); ads7843e_waitbusy(priv); /* Read the data */ SPI_RECVBLOCK(priv->spi, buffer, 2); ads7843e_deselect(priv->spi); 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 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(&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; bool pendown; 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 */ wd_cancel(priv->wdog); /* 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) { /* 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) { goto errout; } /* 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) { goto errout; } else { /* Handle pen down events. First, sample positional values. */ priv->sample.x = ads7843e_sendcmd(priv, ADS7843_CMD_XPOSITION); priv->sample.y = ads7843e_sendcmd(priv, ADS7843_CMD_YPOSITION); /* 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; } /* Continue to sample the position while the pen is down */ wd_start(priv->wdog, ADS7843E_WDOG_DELAY, ads7843e_wdog, 1, (uint32_t)priv); } /* 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 */ errout: (void)ads7843e_sendcmd(priv, ADS7843_CMD_ENABPINIRQ); config->enable(config, true); } /**************************************************************************** * 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 = priv->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 | TOUCH_PRESSURE_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; pollevent_t eventset; int ndx; int ret = OK; 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 *dev, 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("dev: %p minor: %d\n", dev, minor); /* Debug-only sanity checks */ DEBUGASSERT(dev != 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 = dev; /* Save the SPI device handle */ priv->config = config; /* Save the board configuration */ priv->wdog = wd_create(); /* Create a watchdog timer */ 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; } /* Configure the SPI interface */ ads7843e_configspi(dev); /* Enable the PEN IRQ */ ads7843e_sendcmd(priv, ADS7843_CMD_ENABPINIRQ); /* 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(&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; }