/**************************************************************************** * drivers/input/ads7843e.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: * "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 */ /**************************************************************************** * Included Files ****************************************************************************/ #include #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 ****************************************************************************/ /* 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 ads7843e_lock(FAR struct spi_dev_s *spi); static void ads7843e_unlock(FAR struct spi_dev_s *spi); 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, FAR void *arg); /* 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); static int ads7843e_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 ads7843e_fops = { ads7843e_open, /* open */ ads7843e_close, /* close */ ads7843e_read, /* read */ NULL, /* write */ NULL, /* seek */ ads7843e_ioctl, /* ioctl */ ads7843e_poll /* poll */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , NULL /* unlink */ #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 ****************************************************************************/ /**************************************************************************** * Name: 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. * * Input Parameters: * spi - Reference to the SPI driver structure * * Returned Value: * None * * Assumptions: * ****************************************************************************/ static void ads7843e_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 * ADS7843 (it might have gotten configured for a different device while * unlocked) */ SPI_SELECT(spi, SPIDEV_TOUCHSCREEN(0), true); SPI_SETMODE(spi, CONFIG_ADS7843E_SPIMODE); SPI_SETBITS(spi, 8); SPI_HWFEATURES(spi, 0); SPI_SETFREQUENCY(spi, CONFIG_ADS7843E_FREQUENCY); SPI_SELECT(spi, SPIDEV_TOUCHSCREEN(0), false); } /**************************************************************************** * Name: ads7843e_unlock * * Description: * Un-lock the SPI bus after each transfer, possibly losing the current * configuration if we are sharing the bus with other devices. * * Input Parameters: * spi - Reference to the SPI driver structure * * Returned Value: * None * * Assumptions: * ****************************************************************************/ static void ads7843e_unlock(FAR struct spi_dev_s *spi) { /* Relinquish the SPI bus. */ SPI_LOCK(spi, false); } /**************************************************************************** * 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 * Acquisition AAAAAAAAAAA * TIME * BUSY BBBBBBBB * Reported * 12-bit DDDDDDDDDDDD... * response * * The BUSY output is high impedance 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(0), true); /* Send the command */ SPI_SEND(priv->spi, cmd); /* Wait a tiny amount to make sure that the acquisition 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(0), false); result = ((uint16_t)buffer[0] << 8) | (uint16_t)buffer[1]; result = result >> 4; iinfo("cmd:%02x response:%04x\n", cmd, result); return result; } /**************************************************************************** * Name: ads7843e_notify ****************************************************************************/ static void ads7843e_notify(FAR struct ads7843e_dev_s *priv) { int i; /* 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. */ for (i = 0; i < CONFIG_ADS7843E_NPOLLWAITERS; i++) { struct pollfd *fds = priv->fds[i]; if (fds) { fds->revents |= POLLIN; iinfo("Report events: %02x\n", fds->revents); nxsem_post(fds->sem); } } /* 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. */ nxsem_post(&priv->waitsem); } } /**************************************************************************** * 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 = enter_critical_section(); /* 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; } leave_critical_section(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 = 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. */ nxsem_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 */ 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 = nxsem_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. */ leave_critical_section(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) { ierr("ERROR: Failed to queue work: %d\n", ret); } return OK; } /**************************************************************************** * Name: ads7843e_wdog ****************************************************************************/ static void ads7843e_wdog(wdparm_t arg) { FAR struct ads7843e_dev_s *priv = (FAR struct ads7843e_dev_s *)arg; 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; 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 */ ads7843e_lock(priv->spi); /* Get exclusive access to the driver data structure */ do { ret = nxsem_wait_uninterruptible(&priv->devsem); /* This would only fail if something canceled the worker thread? * That is not expected. */ DEBUGASSERT(ret == OK || ret == -ECANCELED); } 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 sample again * later. */ wd_start(&priv->wdog, ADS7843E_WDOG_DELAY, ads7843e_wdog, (wdparm_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 add_ui_randomness((x << 16) | y); /* 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, (wdparm_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 */ 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 */ nxsem_post(&priv->devsem); ads7843e_unlock(priv->spi); } /**************************************************************************** * Name: ads7843e_interrupt ****************************************************************************/ static int ads7843e_interrupt(int irq, FAR void *context, FAR void *arg) { 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); 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 = 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; iinfo("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 = nxsem_wait(&priv->devsem); 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_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: nxsem_post(&priv->devsem); return ret; #else iinfo("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; iinfo("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 = nxsem_wait(&priv->devsem); 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--; } nxsem_post(&priv->devsem); #endif iinfo("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; iinfo("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? */ ierr("ERROR: Unsupported read size: %d\n", len); return -ENOSYS; } /* Get exclusive access to the driver data structure */ ret = nxsem_wait(&priv->devsem); if (ret < 0) { ierr("ERROR: nxsem_wait: %d\n", ret); return ret; } /* 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. */ iinfo("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 */ ierr("ERROR: 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; } 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: nxsem_post(&priv->devsem); iinfo("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; iinfo("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 = nxsem_wait(&priv->devsem); 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; } nxsem_post(&priv->devsem); return ret; } /**************************************************************************** * Name: ads7843e_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; iinfo("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 = nxsem_wait(&priv->devsem); 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_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: nxsem_post(&priv->devsem); return ret; } /**************************************************************************** * 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; 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 ADS7843E device driver instance */ #ifndef CONFIG_ADS7843E_MULTIPLE priv = &g_ads7843e; #else priv = (FAR struct ads7843e_dev_s *) kmm_malloc(sizeof(struct ads7843e_dev_s)); if (!priv) { ierr("ERROR: kmm_malloc(%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->threshx = INVALID_THRESHOLD; /* Initialize thresholding logic */ priv->threshy = INVALID_THRESHOLD; /* Initialize thresholding logic */ /* Initialize semaphores */ nxsem_init(&priv->devsem, 0, 1); /* Initialize device structure semaphore */ nxsem_init(&priv->waitsem, 0, 0); /* Initialize pen event wait semaphore */ /* The pen event semaphore is used for signaling and, hence, should not * have priority inheritance enabled. */ nxsem_set_protocol(&priv->waitsem, SEM_PRIO_NONE); /* 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) { ierr("ERROR: Failed to attach interrupt\n"); goto errout_with_priv; } iinfo("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); /* Enable the PEN IRQ */ ads7843e_sendcmd(priv, ADS7843_CMD_ENABPENIRQ); /* Unlock the bus */ ads7843e_unlock(spi); /* Register the device as an input device */ snprintf(devname, DEV_NAMELEN, DEV_FORMAT, minor); iinfo("Registering %s\n", devname); ret = register_driver(devname, &ads7843e_fops, 0666, priv); if (ret < 0) { ierr("ERROR: 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 received IRQ number. */ #ifdef CONFIG_ADS7843E_MULTIPLE flags = enter_critical_section(); priv->flink = g_ads7843elist; g_ads7843elist = 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, ads7843e_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: nxsem_destroy(&priv->devsem); #ifdef CONFIG_ADS7843E_MULTIPLE kmm_free(priv); #endif return ret; }