diff options
Diffstat (limited to 'nuttx/drivers/input/stmpe811_tsc.c')
| -rw-r--r-- | nuttx/drivers/input/stmpe811_tsc.c | 1144 |
1 files changed, 1144 insertions, 0 deletions
diff --git a/nuttx/drivers/input/stmpe811_tsc.c b/nuttx/drivers/input/stmpe811_tsc.c new file mode 100644 index 000000000..e2ab2827d --- /dev/null +++ b/nuttx/drivers/input/stmpe811_tsc.c @@ -0,0 +1,1144 @@ +/**************************************************************************** + * drivers/input/stmpe811_tsc.c + * + * Copyright (C) 2012 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * References: + * "STMPE811 S-Touch® advanced resistive touchscreen controller with 8-bit + * GPIO expander," Doc ID 14489 Rev 6, CD00186725, STMicroelectronics" + * + * 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 <errno.h> +#include <assert.h> +#include <debug.h> + +#include <nuttx/kmalloc.h> +#include <nuttx/arch.h> +#include <nuttx/fs/fs.h> +#include <nuttx/i2c.h> +#include <nuttx/wqueue.h> + +#include <nuttx/arch.h> +#include <nuttx/input/touchscreen.h> +#include <nuttx/input/stmpe811.h> + +#include "stmpe811.h" + +#if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_STMPE811) && !defined(CONFIG_STMPE811_TSC_DISABLE) + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +#define Direction_IN 0x00 +#define Direction_OUT 0x01 + +#define Polarity_Low 0x00 +#define Polarity_High 0x04 +#define Type_Level 0x00 +#define Type_Edge 0x02 + +#define IO_IT_0 0x01 +#define IO_IT_1 0x02 +#define IO_IT_2 0x04 +#define IO_IT_3 0x08 +#define IO_IT_4 0x10 +#define IO_IT_5 0x20 +#define IO_IT_6 0x40 +#define IO_IT_7 0x80 +#define ALL_IT 0xFF +#define IOE_JOY_IT (uint8_t)(IO_IT_3 | IO_IT_4 | IO_IT_5 | IO_IT_6 | IO_IT_7) +#define IOE_TS_IT (uint8_t)(IO_IT_0 | IO_IT_1 | IO_IT_2) +#define IOE_INMEMS_IT (uint8_t)(IO_IT_2 | IO_IT_3) + +#define EDGE_FALLING 0x01 +#define EDGE_RISING 0x02 + +#define TIMEOUT_MAX 0x3000 /*<! The value of the maximal timeout for I2C waiting loops */ + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ +/* Internal logic */ + +static void stmpe811_notify(FAR struct stmpe811_dev_s *priv); +static int stmpe811_sample(FAR struct stmpe811_dev_s *priv, + FAR struct stmpe811_sample_s *sample); +static inline int stmpe811_waitsample(FAR struct stmpe811_dev_s *priv, + FAR struct stmpe811_sample_s *sample); + +/* Character driver methods */ + +static int stmpe811_open(FAR struct file *filep); +static int stmpe811_close(FAR struct file *filep); +static ssize_t stmpe811_read(FAR struct file *filep, FAR char *buffer, + size_t len); +static int stmpe811_ioctl(FAR struct file *filep, int cmd, + unsigned long arg); +#ifndef CONFIG_DISABLE_POLL +static int stmpe811_poll(FAR struct file *filep, struct pollfd *fds, + bool setup); +#endif + +/* Initialization logic */ + +static inline void stmpe811_tscinitialize(FAR struct stmpe811_dev_s *priv); + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/* This the the vtable that supports the character driver interface */ + +static const struct file_operations g_stmpe811fops = +{ + stmpe811_open, /* open */ + stmpe811_close, /* close */ + stmpe811_read, /* read */ + 0, /* write */ + 0, /* seek */ + stmpe811_ioctl /* ioctl */ +#ifndef CONFIG_DISABLE_POLL + , stmpe811_poll /* poll */ +#endif +}; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ +/**************************************************************************** + * Name: stmpe811_notify + * + * Description: + * Notify any threads waiting on touchscreen data that data is now + * available for reading. + * + ****************************************************************************/ + +static void stmpe811_notify(FAR struct stmpe811_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 STMPE811 + * is no longer available. + */ + + sem_post(&priv->waitsem); + } + + /* If there are threads waiting on poll() for STMPE811 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_STMPE811_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: stmpe811_sample + * + * Description: + * Check if touchscreen sample data is available now and, if so, return + * the sample data. This is part of the stmpe811_read logic. + * + * Assumption: + * Pre-emption is disable to prevent the worker thread from running. + * Otherwise, sampled data may continue to change. + * + ****************************************************************************/ + +static int stmpe811_sample(FAR struct stmpe811_dev_s *priv, + FAR struct stmpe811_sample_s *sample) +{ + int ret = -EAGAIN; + + /* Is there new STMPE811 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 stmpe811_sample_s)); + + /* Now manage state transitions */ + + if (sample->contact == CONTACT_UP) + { + /* The sampling logic has detected pen-up in some condition other + * than CONTACT_NONE. Set the next state to CONTACT_NONE: Further + * pen-down reports will be ignored. Increment the ID so that + * next contact ID will be unique + */ + + priv->sample.contact = CONTACT_NONE; + priv->sample.valid = false; + priv->id++; + } + else if (sample->contact == CONTACT_DOWN) + { + /* The sampling logic has detected pen-up in some condition other + * than CONTACT_MOVE. Set the next state to CONTACT_MOVE: Further + * samples collected while the pen is down will reported as movement + * events. + */ + + priv->sample.contact = CONTACT_MOVE; + } + + priv->penchange = false; + ret = OK; + } + + return ret; +} + +/**************************************************************************** + * Name: stmpe811_waitsample + * + * Description: + * Wait for a sample to become available (this is really part of the + * stmpe811_read logic). + * + ****************************************************************************/ + +static inline int stmpe811_waitsample(FAR struct stmpe811_dev_s *priv, + FAR struct stmpe811_sample_s *sample) +{ + int ret; + + /* Disable pre-emption to prevent the worker thread from running + * asynchronously. + */ + + sched_lock(); + + /* 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->exclsem); + + /* Try to get the a sample... if we cannot, then wait on the semaphore + * that is posted when new sample data is availble. + */ + + while (stmpe811_sample(priv, sample) < 0) + { + /* Wait for a change in the STMPE811 state */ + + priv->nwaiters++; + ret = sem_wait(&priv->waitsem); + priv->nwaiters--; + + /* When we are re-awakened, pre-emption will again be disabled */ + + if (ret < 0) + { +#ifdef CONFIG_DEBUG + // Sample the errno (debug output could change it) + + int errval = errno; + + /* If we are awakened by a signal, then we need to return + * the failure now. + */ + + idbg("ERROR: sem_wait failed: %d\n", errval); + DEBUGASSERT(errval == EINTR); +#endif + ret = -EINTR; + goto errout; + } + } + + /* 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->exclsem); + +errout: + /* 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 STMPE811 for some reason, the data + * might be read out of order. + */ + + sched_unlock(); + return ret; +} + +/**************************************************************************** + * Name: stmpe811_open + * + * Description: + * Standard character driver open method. + * + ****************************************************************************/ + +static int stmpe811_open(FAR struct file *filep) +{ +#ifdef CONFIG_STMPE811_REFCNT + FAR struct inode *inode; + FAR struct stmpe811_dev_s *priv; + uint8_t tmp; + int ret; + + DEBUGASSERT(filep); + inode = filep->f_inode; + + DEBUGASSERT(inode && inode->i_private); + priv = (FAR struct stmpe811_dev_s *)inode->i_private; + + /* Get exclusive access to the driver data structure */ + + ret = sem_wait(&priv->exclsem); + 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->exclsem); + return ret; +#else + return OK; +#endif +} + +/**************************************************************************** + * Name: stmpe811_close + * + * Description: + * Standard character driver close method. + * + ****************************************************************************/ + +static int stmpe811_close(FAR struct file *filep) +{ +#ifdef CONFIG_STMPE811_REFCNT + FAR struct inode *inode; + FAR struct stmpe811_dev_s *priv; + int ret; + + DEBUGASSERT(filep); + inode = filep->f_inode; + + DEBUGASSERT(inode && inode->i_private); + priv = (FAR struct stmpe811_dev_s *)inode->i_private; + + /* Get exclusive access to the driver data structure */ + + ret = sem_wait(&priv->exclsem); + 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->exclsem); +#endif + return OK; +} + +/**************************************************************************** + * Name: stmpe811_read + * + * Description: + * Standard character driver read method. + * + ****************************************************************************/ + +static ssize_t stmpe811_read(FAR struct file *filep, FAR char *buffer, size_t len) +{ + FAR struct inode *inode; + FAR struct stmpe811_dev_s *priv; + FAR struct touch_sample_s *report; + struct stmpe811_sample_s sample; + int ret; + + ivdbg("len=%d\n", len); + DEBUGASSERT(filep); + inode = filep->f_inode; + + DEBUGASSERT(inode && inode->i_private); + priv = (FAR struct stmpe811_dev_s *)inode->i_private; + + /* Verify that the caller has provided a buffer large enough to receive + * the touch data. + */ + + if (len < SIZEOF_TOUCH_SAMPLE_S(1)) + { + /* We could provide logic to break up a touch report into segments and + * handle smaller reads... but why? + */ + + return -ENOSYS; + } + + /* Get exclusive access to the driver data structure */ + + ret = sem_wait(&priv->exclsem); + if (ret < 0) + { + /* This should only happen if the wait was canceled by an signal */ + + DEBUGASSERT(errno == EINTR); + return -EINTR; + } + + /* Try to read sample data. */ + + ret = stmpe811_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. + */ + + if (filep->f_oflags & O_NONBLOCK) + { + ret = -EAGAIN; + goto errout; + } + + /* Wait for sample data */ + + ret = stmpe811_waitsample(priv, &sample); + if (ret < 0) + { + /* We might have been awakened by a signal */ + + goto errout; + } + } + + /* In any event, we now have sampled STMPE811 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->point[0].pressure = sample.z; + + /* 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 | TOUCH_PRESSURE_VALID; + } + else /* if (sample->contact == CONTACT_MOVE) */ + { + /* Movement of the same contact */ + + report->point[0].flags = TOUCH_MOVE | TOUCH_ID_VALID | + TOUCH_POS_VALID | TOUCH_PRESSURE_VALID; + } + + ret = SIZEOF_TOUCH_SAMPLE_S(1); + +errout: + sem_post(&priv->exclsem); + return ret; +} + +/**************************************************************************** + * Name: stmpe811_ioctl + * + * Description: + * Standard character driver ioctl method. + * +****************************************************************************/ + +static int stmpe811_ioctl(FAR struct file *filep, int cmd, unsigned long arg) +{ + FAR struct inode *inode; + FAR struct stmpe811_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 stmpe811_dev_s *)inode->i_private; + + /* Get exclusive access to the driver data structure */ + + ret = sem_wait(&priv->exclsem); + 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 = I2C_SETFREQUENCY(priv->i2c, *ptr); + } + break; + + case TSIOC_GETFREQUENCY: /* arg: Pointer to uint32_t frequency value */ + { + FAR uint32_t *ptr = (FAR uint32_t *)((uintptr_t)arg); + DEBUGASSERT(priv->config != NULL && ptr != NULL); + *ptr = priv->config->frequency; + } + break; + + default: + ret = -ENOTTY; + break; + } + + sem_post(&priv->exclsem); + return ret; +} + +/**************************************************************************** + * Name: stmpe811_poll + * + * Description: + * Standard character driver poll method. + * + ****************************************************************************/ + +#ifndef CONFIG_DISABLE_POLL +static int stmpe811_poll(FAR struct file *filep, FAR struct pollfd *fds, + bool setup) +{ + FAR struct inode *inode; + FAR struct stmpe811_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 stmpe811_dev_s *)inode->i_private; + + /* Are we setting up the poll? Or tearing it down? */ + + ret = sem_wait(&priv->exclsem); + 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) + { + idbg("ERROR: Missing POLLIN: revents: %08x\n", fds->revents); + ret = -EDEADLK; + goto errout; + } + + /* This is a request to set up the poll. Find an available + * slot for the poll structure reference + */ + + for (i = 0; i < CONFIG_STMPE811_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_STMPE811_NPOLLWAITERS) + { + idbg("ERROR: No availabled slot found: %d\n", i); + fds->priv = NULL; + ret = -EBUSY; + goto errout; + } + + /* Should we immediately notify on any of the requested events? */ + + if (priv->penchange) + { + stmpe811_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->exclsem); + return ret; +} +#endif + +/**************************************************************************** + * Name: stmpe811_timeoutworker + * + * Description: + * A timer has expired without receiving a pen up event. Check again. + * + ****************************************************************************/ + +static void stmpe811_timeoutworker(FAR void *arg) +{ + FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)arg; + + DEBUGASSERT(priv); + + /* Treat the timeout just like an interrupt occurred */ + + stmpe811_tscworker(priv, stmpe811_getreg8(priv, STMPE811_INT_STA)); +} + +/**************************************************************************** + * Name: stmpe811_timeout + * + * Description: + * A timer has expired without receiving a pen up event. Schedule work + * to check again. + * + ****************************************************************************/ + +static void stmpe811_timeout(int argc, uint32_t arg1, ...) +{ + FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)((uintptr_t)arg1); + int ret; + + /* Are we still stuck in the pen down state? */ + + if (priv->sample.contact == CONTACT_MOVE || + priv->sample.contact == CONTACT_MOVE) + { + /* Yes... is the worker thread available? If not, then apparently + * we have work already pending? + */ + + if (work_available(&priv->timeout)) + { + /* Yes.. Transfer processing to the worker thread. Since STMPE811 + * interrupts are disabled while the work is pending, no special + * action should be required to protect the work queue. + */ + + ret = work_queue(&priv->timeout, stmpe811_timeoutworker, priv, 0); + if (ret != 0) + { + illdbg("Failed to queue work: %d\n", ret); + } + } + } +} + +/**************************************************************************** + * Name: stmpe811_tscinitialize + * + * Description: + * Initialize the touchscreen controller. This is really a part of the + * stmpe811_register logic, + * + ****************************************************************************/ + +static inline void stmpe811_tscinitialize(FAR struct stmpe811_dev_s *priv) +{ + uint8_t regval; + + ivdbg("Initializing touchscreen controller\n"); + + /* Enable TSC and ADC functions */ + + regval = stmpe811_getreg8(priv, STMPE811_SYS_CTRL2); + regval &= ~(SYS_CTRL2_TSC_OFF | SYS_CTRL2_ADC_OFF); + stmpe811_putreg8(priv, STMPE811_SYS_CTRL2, regval); + + /* Enable the TSC global interrupts */ + + regval = stmpe811_getreg8(priv, STMPE811_INT_EN); + regval |= (uint32_t)(INT_TOUCH_DET | INT_FIFO_TH | INT_FIFO_OFLOW); + stmpe811_putreg8(priv, STMPE811_INT_EN, regval); + + /* Select Sample Time, bit number and ADC Reference */ + + stmpe811_putreg8(priv, STMPE811_ADC_CTRL1, priv->config->ctrl1); + + /* Wait for 20 ms */ + + up_mdelay(20); + + /* Select the ADC clock speed */ + + stmpe811_putreg8(priv, STMPE811_ADC_CTRL2, priv->config->ctrl2); + + /* Select TSC pins in non-GPIO mode (AF=0) */ + + regval = stmpe811_getreg8(priv, STMPE811_GPIO_AF); + regval &= ~(uint8_t)TSC_PIN_SET; + stmpe811_putreg8(priv, STMPE811_GPIO_AF, regval); + + /* Select 2 nF filter capacitor */ + + stmpe811_putreg8(priv, STMPE811_TSC_CFG, + (TSC_CFG_AVE_CTRL_4SAMPLES | TSC_CFG_TOUCH_DELAY_500US | TSC_CFG_SETTLING_500US)); + + /* Select single point reading */ + + stmpe811_putreg8(priv, STMPE811_FIFO_TH, 1); + + /* Reset and clear the FIFO. */ + + stmpe811_putreg8(priv, STMPE811_FIFO_STA, FIFO_STA_FIFO_RESET); + stmpe811_putreg8(priv, STMPE811_FIFO_STA, 0); + + /* set the data format for Z value: 7 fractional part and 1 whole part */ + + stmpe811_putreg8(priv, STMPE811_TSC_FRACTIONZ, 0x01); + + /* Set the driving capability of the device for TSC pins: 50mA */ + + stmpe811_putreg8(priv, STMPE811_TSC_IDRIVE, TSC_IDRIVE_50MA); + + /* Enable the TSC. Use no tracking index, touch-screen controller + * operation mode (XYZ). + */ + + stmpe811_putreg8(priv, STMPE811_TSC_CTRL, TSC_CTRL_EN); + + /* Clear all the status pending bits */ + + stmpe811_putreg8(priv, STMPE811_INT_STA, INT_ALL); +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: stmpe811_register + * + * Description: + * Enable TSC functionality. GPIO4-7 must be available. This function + * will register the touchsceen driver as /dev/inputN where N is the minor + * device number + * + * Input Parameters: + * handle - The handle previously returned by stmpe811_register + * 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 stmpe811_register(STMPE811_HANDLE handle, int minor) +{ + FAR struct stmpe811_dev_s *priv = (FAR struct stmpe811_dev_s *)handle; + char devname[DEV_NAMELEN]; + int ret; + + ivdbg("handle=%p minor=%d\n", handle, minor); + DEBUGASSERT(priv); + + /* Get exclusive access to the device structure */ + + ret = sem_wait(&priv->exclsem); + if (ret < 0) + { + int errval = errno; + idbg("ERROR: sem_wait failed: %d\n", errval); + return -errval; + } + + /* Make sure that the pins (4-7) need by the TSC are not already in use */ + + if ((priv->inuse & TSC_PIN_SET) != 0) + { + idbg("ERROR: TSC pins is already in-use: %02x\n", priv->inuse); + sem_post(&priv->exclsem); + return -EBUSY; + } + + /* Initialize the TS structure fields to their default values */ + + priv->minor = minor; + priv->penchange = false; + priv->threshx = 0; + priv->threshy = 0; + + /* Create a timer for catching missed pen up conditions */ + + priv->wdog = wd_create(); + if (!priv->wdog) + { + idbg("ERROR: Failed to create a watchdog\n", errno); + sem_post(&priv->exclsem); + return -ENOSPC; + } + + /* Register the character driver */ + + snprintf(devname, DEV_NAMELEN, DEV_FORMAT, minor); + ret = register_driver(devname, &g_stmpe811fops, 0666, priv); + if (ret < 0) + { + idbg("ERROR: Failed to register driver %s: %d\n", devname, ret); + sem_post(&priv->exclsem); + return ret; + } + + /* Initialize the touchscreen controller */ + + stmpe811_tscinitialize(priv); + + /* Inidicate that the touchscreen controller was successfully initialized */ + + priv->inuse |= TSC_PIN_SET; /* Pins 4-7 are now in-use */ + priv->flags |= STMPE811_FLAGS_TSC_INITIALIZED; /* TSC function is initialized */ + sem_post(&priv->exclsem); + return ret; +} + +/**************************************************************************** + * Name: stmpe811_tscworker + * + * Description: + * This function is called to handle a TSC interrupt. It is not really + * an interrupt handle because it is called from the STMPE811 "bottom half" + * logic that runs on the worker thread. + * + ****************************************************************************/ + +void stmpe811_tscworker(FAR struct stmpe811_dev_s *priv, uint8_t intsta) +{ + FAR struct stmpe811_config_s *config; /* Convenience pointer */ + bool pendown; /* true: pend is down */ + uint16_t xdiff; /* X difference used in thresholding */ + uint16_t ydiff; /* Y difference used in thresholding */ + uint16_t x; /* X position */ + uint16_t y; /* Y position */ + + ASSERT(priv != NULL); + + /* Cancel the missing pen up timer */ + + (void)wd_cancel(priv->wdog); + + /* Get a pointer the callbacks for convenience (and so the code is not so + * ugly). + */ + + config = priv->config; + DEBUGASSERT(config != NULL); + + /* Check for pen up or down from the TSC_STA ibit n the STMPE811_TSC_CTRL register. */ + + pendown = (stmpe811_getreg8(priv, STMPE811_TSC_CTRL) & TSC_CTRL_TSC_STA) != 0; + + /* Handle the change from pen down to pen up */ + + if (!pendown) + { + /* The pen is up.. reset thresholding variables. FIFOs will read zero if + * there is no data available (hence the choice of (0,0)) + */ + + priv->threshx = 0; + priv->threshy = 0; + + /* 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; + } + + /* A pen-down to up transition has been detected. CONTACT_UP indicates the + * initial loss of contzt. The state will be changed to CONTACT_NONE + * after the loss of contact is sampled. + */ + + priv->sample.contact = CONTACT_UP; + } + + /* The pen is down... check for data in the FIFO */ + + else if ((intsta & (INT_FIFO_TH|INT_FIFO_OFLOW)) != 0) + { + /* Read the next x and y positions from the FIFO. */ + +#ifdef CONFIG_STMPE811_SWAPXY + x = stmpe811_getreg16(priv, STMPE811_TSC_DATAX); + y = stmpe811_getreg16(priv, STMPE811_TSC_DATAY); +#else + x = stmpe811_getreg16(priv, STMPE811_TSC_DATAY); + y = stmpe811_getreg16(priv, STMPE811_TSC_DATAX); +#endif + + /* 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 there will be another FIFO event right behind + * this one. Other kinds of data overruns are not harmful. + * + * Hmm.. a better design might be to disable FIFO interrupts when we + * detect pen up. Then re-enable them when CONTACT_UP is reported. + * That would save processing interrupts just to discard the data. + */ + + if (priv->sample.contact == CONTACT_UP) + { + /* We have not closed the loop on the last touch ... don't report + * anything. + */ + + goto ignored; + } + + /* Perform a thresholding operation so that the results will be more stable. + * If the difference from the last sample is small, then ignore the event. + * REVISIT: Should a large change in pressure also generate a event? + */ + + xdiff = x > priv->threshx ? (x - priv->threshx) : (priv->threshx - x); + ydiff = y > priv->threshy ? (y - priv->threshy) : (priv->threshy - y); + + if (xdiff < CONFIG_STMPE811_THRESHX && ydiff < CONFIG_STMPE811_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; + + /* Update the Z pressure index */ + + priv->sample.z = stmpe811_getreg8(priv, STMPE811_TSC_DATAZ); + 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; + } + } + + /* Pen down, but no data in FIFO */ + + else + { + /* Ignore the interrupt... wait until there is data in the FIFO */ + + goto ignored; + } + + /* We get here if (1) we just went from a pen down to a pen up state OR (2) + * We just get a measurement from the FIFO in a pen down state. Indicate + * the availability of new sample data for this ID. + */ + + priv->sample.id = priv->id; + priv->penchange = true; + + /* Notify any waiters that new STMPE811 data is available */ + + stmpe811_notify(priv); + + /* If we think that the pend is still down, the start/re-start the pen up + * timer. + */ + +ignored: + if (priv->sample.contact == CONTACT_MOVE || + priv->sample.contact == CONTACT_MOVE) + { + (void)wd_start(priv->wdog, STMPE811_PENUP_TICKS, stmpe811_timeout, + 1, (uint32_t)((uintptr_t)priv)); + } + + /* Reset and clear all data in the FIFO */ + + stmpe811_putreg8(priv, STMPE811_FIFO_STA, FIFO_STA_FIFO_RESET); + stmpe811_putreg8(priv, STMPE811_FIFO_STA, 0); +} + +#endif /* CONFIG_INPUT && CONFIG_INPUT_STMPE811 && !CONFIG_STMPE811_TSC_DISABLE */ + |