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apache / nuttx / refs/heads/revert-17300-apache_6 / . / boards / arm / stm32 / mikroe-stm32f4 / src / stm32_touchscreen.c
blob: a370550b90b35582c86bb79b55fd1c737be034c7 [file] [log] [blame]
/****************************************************************************
* boards/arm/stm32/mikroe-stm32f4/src/stm32_touchscreen.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <poll.h>
#include <sched.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/board.h>
#include <nuttx/clock.h>
#include <nuttx/wqueue.h>
#include <nuttx/fs/fs.h>
#include <nuttx/input/touchscreen.h>
#include <nuttx/mutex.h>
#include <nuttx/semaphore.h>
#include <arch/board/board.h>
#include "arm_internal.h"
#include "stm32_adc.h"
#include "stm32_gpio.h"
#include "mikroe-stm32f4.h"
#ifdef CONFIG_INPUT
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
/* Reference counting is partially implemented, but not needed in the current
* design.
*/
#define CONFIG_TOUCHSCREEN_REFCNT
/* Should we try again on bad samples? */
#undef CONFIG_TOUCHSCREEN_RESAMPLE
/* TP uses ADC Channel #2 in a dedicated mode. Ensure ADC2 not selected for
* general use via the menuconfig
*/
#ifndef CONFIG_STM32_ADC2
# error Touchpanel Input (CONFIG_INPUT=y) requires enablinga ADC2 (CONFIG_STM32_ADC2=y)
#endif
/* Work queue support is required */
#ifndef CONFIG_SCHED_WORKQUEUE
# warning Work queue support is required (CONFIG_SCHED_WORKQUEUE=y)
#endif
/* CONFIG_TOUCHSCREEN_THRESHX and CONFIG_TOUCHSCREEN_THRESHY
* Touchscreen data comes in a a very high rate. New touch positions
* will only be reported when the X or Y data changes by these thresholds.
* This trades reduces data rate for some loss in dragging accuracy. The
* touchscreen is configure for 12-bit values so the raw ranges are 0-4096.
* So for example, if your display is 320x240, then THRESHX=3 and THRESHY=4
* would correspond to one pixel. Default: 4
*/
#ifndef CONFIG_TOUCHSCREEN_THRESHX
# define CONFIG_TOUCHSCREEN_THRESHX 12
#endif
#ifndef CONFIG_TOUCHSCREEN_THRESHY
# define CONFIG_TOUCHSCREEN_THRESHY 12
#endif
#ifndef CONFIG_TOUCHSCREEN_AVG_SAMPLES
# define CONFIG_TOUCHSCREEN_AVG_SAMPLES 2
#endif
#ifndef CONFIG_TOUCHSCREEN_NPOLLWAITERS
# define CONFIG_TOUCHSCREEN_NPOLLWAITERS 2
#endif
/* Driver support ***********************************************************/
/* This format is used to construct the /dev/input[n] device driver path. It
* is defined here so that it will be used consistently in all places.
*/
#define DEV_FORMAT "/dev/input%d"
#define DEV_NAMELEN 16
/* Mikroe-STM32M4 Touchscreen Hardware Definitions **************************
* PIN CONFIGURATIONS SIGNAL NAME ON-BOARD CONNECTIONS
* --- ---------------------------------- -------------------- --------------
* 35 PB0 LCD-YD YD Analog input
* 36 PB1 LCD-XL XL Analog input
* 95 PB8 DRIVEA Drives XR, XL and YU
* 96 PB9 DRIVEB Drives YD
*/
#define LCD_YD_PIN (0)
#define LCD_XL_PIN (1)
#define LCD_YD_CHANNEL (8)
#define LCD_XL_CHANNEL (9)
#define LCD_DRIVEA_PIN (8)
#define LCD_DRIVEB_PIN (9)
#define LCD_DRIVEA_BIT (1 << LCD_DRIVEA_PIN)
#define LCD_DRIVEB_BIT (1 << LCD_DRIVEB_PIN)
#define LCD_SAMPX_BITS (LCD_DRIVEA_BIT | (LCD_DRIVEB_BIT << 16))
#define LCD_SAMPY_BITS (LCD_DRIVEB_BIT | (LCD_DRIVEA_BIT << 16))
#define LCD_TP_PORT_SETRESET STM32_GPIOB_BSRR
#define TC_ADC_BASE STM32_ADC2_BASE /* ADC Channel base for TP */
#define ADC_CR1_ALLINTS (ADC_CR1_AWDIE | ADC_CR1_EOCIE | ADC_CR1_JEOCIE)
/* Conversions are performed as 10-bit samples represented as 16-bit */
#define MAX_ADC (4096)
/* A measured value has to be within this range to be considered */
#define UPPER_THRESHOLD (MAX_ADC-1)
#define LOWER_THRESHOLD (362)
/* Delays *******************************************************************/
/* All values will be increased by one system timer tick (probably 10MS). */
#define TC_PENUP_POLL_TICKS MSEC2TICK(70) /* IDLE polling rate: 70 MSec */
#define TC_PENDOWN_POLL_TICKS MSEC2TICK(40) /* Active polling rate: 40 MSec */
#define TC_DEBOUNCE_TICKS MSEC2TICK(16) /* Delay before re-sampling: 16 MSec */
#define TC_SAMPLE_TICKS MSEC2TICK(4) /* Delay for A/D sampling: 4 MSec */
#define TC_SETTLE_TICKS MSEC2TICK(10) /* Delay for A/D settling: 10 MSec */
#define TC_RESAMPLE_TICKS TC_SAMPLE_TICKS
/****************************************************************************
* Private Types
****************************************************************************/
/* This enumeration describes the state of touchscreen state machine */
enum tc_state_e
{
TC_READY = 0, /* Ready to begin next sample */
TC_READY_SETTLE, /* Allowing time for Y DRIVE to settle */
TC_YPENDOWN, /* Allowing time for the Y pen down sampling */
TC_DEBOUNCE, /* Allowing a debounce time for the first sample */
TC_RESAMPLE, /* Restart sampling on a bad measurement */
TC_YSAMPLE, /* Allowing time for the Y sampling */
TC_XSETTLE, /* Allowing time for the X to settle after changing DRIVE */
TC_XSAMPLE, /* Allowing time for the X sampling */
TC_XRESAMPLE, /* Allow time to resample X */
TC_PENDOWN, /* Conversion is complete -- pen down */
TC_PENUP /* Conversion is complete -- pen up */
};
/* This describes the state of one contact */
enum tc_contact_e
{
CONTACT_NONE = 0, /* No contact */
CONTACT_DOWN, /* First contact */
CONTACT_MOVE, /* Same contact, possibly different position */
CONTACT_UP, /* Contact lost */
};
/* This structure describes the results of one touchscreen sample */
struct tc_sample_s
{
uint8_t id; /* Sampled touch point ID */
uint8_t contact; /* Contact state (see enum tc_contact_e) */
bool valid; /* True: x,y contain valid, sampled data */
uint16_t x; /* Thresholded X position */
uint16_t y; /* Thresholded Y position */
};
/* This structure describes the state of one touchscreen driver instance */
struct tc_dev_s
{
#ifdef CONFIG_TOUCHSCREEN_REFCNT
uint8_t crefs; /* Number of times the device has been opened */
#endif
uint8_t state; /* See enum tc_state_e */
uint8_t nwaiters; /* Number of threads waiting for touchscreen data */
uint8_t id; /* Current touch point ID */
volatile bool penchange; /* An unreported event is buffered */
uint16_t value; /* Partial sample value (Y+ or X-) */
uint16_t newy; /* New, un-thresholded Y value */
uint8_t sampcount; /* Count of samples for average so far */
uint8_t resamplecount; /* Countdown to PENUP */
mutex_t devlock; /* Manages exclusive access to this structure */
sem_t waitsem; /* Used to wait for the availability of data */
struct tc_sample_s sample; /* Last sampled touch point data */
struct work_s work; /* Supports the state machine delayed processing */
/* The following is a list if poll structures of threads waiting for
* driver events. The 'struct pollfd' reference for each open is also
* retained in the f_priv field of the 'struct file'.
*/
struct pollfd *fds[CONFIG_TOUCHSCREEN_NPOLLWAITERS];
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void tc_adc_init(void);
static void tc_adc_start_sample(int pin);
static uint16_t tc_adc_read_sample(void);
static void tc_y_sample(void);
static void tc_x_sample(void);
static inline bool tc_valid_sample(uint16_t sample);
static void tc_notify(struct tc_dev_s *priv);
static int tc_sample(struct tc_dev_s *priv,
struct tc_sample_s *sample);
static int tc_waitsample(struct tc_dev_s *priv,
struct tc_sample_s *sample);
static void tc_worker(void *arg);
/* Character driver methods */
static int tc_open(struct file *filep);
static int tc_close(struct file *filep);
static ssize_t tc_read(struct file *filep, char *buffer, size_t len);
static int tc_ioctl(struct file *filep, int cmd, unsigned long arg);
static int tc_poll(struct file *filep, struct pollfd *fds, bool setup);
/****************************************************************************
* Private Data
****************************************************************************/
/* This the vtable that supports the character driver interface */
static const struct file_operations g_tc_fops =
{
tc_open, /* open */
tc_close, /* close */
tc_read, /* read */
NULL, /* write */
NULL, /* seek */
tc_ioctl, /* ioctl */
NULL, /* mmap */
NULL, /* truncate */
tc_poll /* poll */
};
/* If only a single touchscreen device is supported, then the driver state
* structure may as well be pre-allocated.
*/
#ifndef CONFIG_TOUCHSCREEN_MULTIPLE
static struct tc_dev_s g_touchscreen;
static bool g_touchinitdone = false;
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: tc_adc_getreg
*
* Description:
* Read the value of an TC ADC channel (#2) register.
*
* Input Parameters:
* offset - The offset to the register to read
* value
*
* Returned Value:
*
****************************************************************************/
static inline uint32_t tc_adc_getreg(int offset)
{
return getreg32(TC_ADC_BASE + offset);
}
/****************************************************************************
* Name: tc_adc_putreg
*
* Description:
* Set the value of an ADC register.
*
* Input Parameters:
* offset - The offset to the register to read
*
* Returned Value:
*
****************************************************************************/
static inline void tc_adc_putreg(int offset, uint32_t value)
{
putreg32(value, TC_ADC_BASE + offset);
}
/****************************************************************************
* Name: tc_adc_init
*
* Description:
* Initialize ADC Channel #2 for use with the touch panel. The touch panel
* uses Channels 8 and 9 (PB0 and PB1) to read the X and Y axis touch
* positions.
*
****************************************************************************/
static void tc_adc_init(void)
{
irqstate_t flags;
uint32_t regval;
/* Do an rcc reset to reset the ADC peripheral */
/* Disable interrupts. This is necessary because the APB2RTSR register
* is used by several different drivers.
*/
flags = enter_critical_section();
/* Enable ADC reset state */
regval = getreg32(STM32_RCC_APB2RSTR);
regval |= RCC_APB2RSTR_ADCRST;
putreg32(regval, STM32_RCC_APB2RSTR);
/* Release ADC from reset state */
regval &= ~RCC_APB2RSTR_ADCRST;
putreg32(regval, STM32_RCC_APB2RSTR);
/* Initialize the watchdog high threshold register */
tc_adc_putreg(STM32_ADC_HTR_OFFSET, 0x00000fff);
/* Initialize the watchdog low threshold register */
tc_adc_putreg(STM32_ADC_LTR_OFFSET, 0x00000000);
/* Initialize the same sample time for each ADC 55.5 cycles
*
* During sample cycles channel selection bits must remain unchanged.
*
* 000: 1.5 cycles
* 001: 7.5 cycles
* 010: 13.5 cycles
* 011: 28.5 cycles
* 100: 41.5 cycles
* 101: 55.5 cycles
* 110: 71.5 cycles
* 111: 239.5 cycles
*/
tc_adc_putreg(STM32_ADC_SMPR1_OFFSET, 0x00b6db6d);
tc_adc_putreg(STM32_ADC_SMPR2_OFFSET, 0x00b6db6d);
/* ADC CR1 Configuration */
regval = tc_adc_getreg(STM32_ADC_CR1_OFFSET);
/* Initialize the Analog watchdog enable */
regval &= ~ADC_CR1_AWDEN;
regval |= (LCD_YD_CHANNEL << ADC_CR1_AWDCH_SHIFT);
/* Enable interrupt flags */
/* regval |= ADC_CR1_ALLINTS; */
/* Disable Overrun interrupt */
regval &= ~ADC_CR1_OVRIE;
/* Set the resolution of the conversion. We only need 10 bits. */
regval |= ADC_CR1_RES_12BIT;
tc_adc_putreg(STM32_ADC_CR1_OFFSET, regval);
/* ADC CR2 Configuration */
regval = tc_adc_getreg(STM32_ADC_CR2_OFFSET);
/* Clear CONT, continuous mode disable. We will perform single
* sampling on one channel at a time.
*/
regval &= ~ADC_CR2_CONT;
/* Set ALIGN (Right = 0) */
regval &= ~ADC_CR2_ALIGN;
/* External trigger disable. We will do SW triggering */
regval &= ~ADC_CR2_EXTEN_MASK;
tc_adc_putreg(STM32_ADC_CR2_OFFSET, regval);
/* Configuration of the channel conversion - start with Y sampling */
regval = tc_adc_getreg(STM32_ADC_SQR3_OFFSET) & ADC_SQR3_RESERVED;
regval |= LCD_YD_CHANNEL;
tc_adc_putreg(STM32_ADC_SQR3_OFFSET, regval);
/* Set the number of conversions = 1 */
regval = tc_adc_getreg(STM32_ADC_SQR1_OFFSET) & ADC_SQR1_RESERVED;
regval |= 0 << ADC_SQR1_L_SHIFT;
tc_adc_putreg(STM32_ADC_SQR1_OFFSET, regval);
/* ADC CCR configuration */
regval = getreg32(STM32_ADC_CCR);
regval &= ~(ADC_CCR_MULTI_MASK | ADC_CCR_DELAY_MASK | ADC_CCR_DDS |
ADC_CCR_DMA_MASK | ADC_CCR_ADCPRE_MASK | ADC_CCR_VBATEN |
ADC_CCR_TSVREFE);
regval |= (ADC_CCR_MULTI_NONE | ADC_CCR_DMA_DISABLED |
ADC_CCR_ADCPRE_DIV2);
putreg32(regval, STM32_ADC_CCR);
/* Set ADON to wake up the ADC from Power Down state. */
regval = tc_adc_getreg(STM32_ADC_CR2_OFFSET);
regval |= ADC_CR2_ADON;
tc_adc_putreg(STM32_ADC_CR2_OFFSET, regval);
/* Restore the IRQ state */
leave_critical_section(flags);
}
/****************************************************************************
* Name: tc_adc_start_sample
*
* Description:
* Perform A/D sampling. Time must be allowed between the start of
* sampling and conversion (approx. 100Ms).
*
****************************************************************************/
static void tc_adc_start_sample(int channel)
{
uint32_t regval;
/* Configure the specified channel for ADC conversion. */
regval = tc_adc_getreg(STM32_ADC_SQR3_OFFSET) & ADC_SQR3_RESERVED;
regval |= channel;
tc_adc_putreg(STM32_ADC_SQR3_OFFSET, regval);
/* Configure the Watchdog for this channel */
regval = tc_adc_getreg(STM32_ADC_CR1_OFFSET) & ADC_CR1_AWDCH_MASK;
regval |= (channel << ADC_CR1_AWDCH_SHIFT);
tc_adc_putreg(STM32_ADC_CR1_OFFSET, regval);
/* Start the conversion */
regval = tc_adc_getreg(STM32_ADC_CR2_OFFSET);
regval |= ADC_CR2_SWSTART;
tc_adc_putreg(STM32_ADC_CR2_OFFSET, regval);
}
/****************************************************************************
* Name: tc_adc_read_sample
*
* Description:
* Begin A/D conversion. Time must be allowed between the start of
* sampling and conversion (approx. 100Ms).
*
* Assumptions:
* 1) All output pins configured as outputs:
* 2) Appropriate pins are driven high and low
*
****************************************************************************/
static uint16_t tc_adc_read_sample(void)
{
uint16_t retval;
uint32_t adcsr;
uint16_t count = 0;
/* Validate the conversion is complete */
adcsr = tc_adc_getreg(STM32_ADC_SR_OFFSET);
while ((adcsr & ADC_SR_EOC) == 0)
{
adcsr = tc_adc_getreg(STM32_ADC_SR_OFFSET);
count++;
}
/* Read the sample */
retval = tc_adc_getreg(STM32_ADC_DR_OFFSET);
retval &= ADC_DR_RDATA_MASK;
if (count > 0)
{
iinfo("Count = %d\n", count);
}
return retval;
}
/****************************************************************************
* Name: tc_y_sample
*
* Description:
* Initiate sampling on Y
*
****************************************************************************/
static void tc_y_sample(void)
{
/* Start the Y axis sampling */
tc_adc_start_sample(LCD_XL_CHANNEL);
}
/****************************************************************************
* Name: tc_x_sample
*
* Description:
* Initiate sampling on X
*
****************************************************************************/
static void tc_x_sample(void)
{
/* Start the X axis sampling */
tc_adc_start_sample(LCD_YD_CHANNEL);
}
/****************************************************************************
* Name: tc_valid_sample
****************************************************************************/
static inline bool tc_valid_sample(uint16_t sample)
{
return (sample > LOWER_THRESHOLD);
}
/****************************************************************************
* Name: tc_notify
****************************************************************************/
static void tc_notify(struct tc_dev_s *priv)
{
/* If no threads have the driver open, then just dump the state */
#ifdef CONFIG_TOUCHSCREEN_REFCNT
if ((priv->crefs == 0) && priv->sample.contact == CONTACT_UP)
{
priv->sample.contact = CONTACT_NONE;
priv->sample.valid = false;
priv->id++;
return;
}
#endif
/* If there are threads waiting on poll() for touchscreen data to become
* available, then wake them up now. NOTE: we wake up all waiting threads
* because we do not know that they are going to do. If they all try to
* read the data, then some make end up blocking after all.
*/
poll_notify(priv->fds, CONFIG_TOUCHSCREEN_NPOLLWAITERS, POLLIN);
/* If there are threads waiting for read data, then signal one of them
* that the read data is available.
*/
if (priv->nwaiters > 0)
{
/* After posting this semaphore, we need to exit because the
* touchscreen is no longer available.
*/
nxsem_post(&priv->waitsem);
}
}
/****************************************************************************
* Name: tc_sample
*
* Assumptions: pre-emption is disabled
*
****************************************************************************/
static int tc_sample(struct tc_dev_s *priv,
struct tc_sample_s *sample)
{
int ret = -EAGAIN;
/* Is there new touchscreen 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 tc_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;
}
return ret;
}
/****************************************************************************
* Name: tc_waitsample
****************************************************************************/
static int tc_waitsample(struct tc_dev_s *priv,
struct tc_sample_s *sample)
{
int ret;
irqstate_t flags;
/* Interrupts must be disabled when this is called to (1) prevent posting
* of semaphores from interrupt handlers, and (2) to prevent sampled data
* from changing until it has been reported.
*/
flags = enter_critical_section();
/* Now release the mutex that manages mutually exclusive access to
* the device structure. This may cause other tasks to become ready to
* run, but they cannot run yet because pre-emption is disabled.
*/
nxmutex_unlock(&priv->devlock);
/* Try to get the a sample... if we cannot, then wait on the semaphore
* that is posted when new sample data is available.
*/
while (tc_sample(priv, sample) < 0)
{
/* Wait for a change in the touchscreen state */
priv->nwaiters++;
ret = nxsem_wait(&priv->waitsem);
priv->nwaiters--;
if (ret < 0)
{
goto errout;
}
}
/* Re-acquire the semaphore that manages mutually exclusive access to
* the device structure. We may have to wait here. But we have our
* sample. Interrupts and pre-emption will be re-enabled while we wait.
*/
ret = nxmutex_lock(&priv->devlock);
errout:
/* Then re-enable interrupts. We might get interrupt here and there
* could be a new sample. But no new threads will run because we still
* have pre-emption disabled.
*/
leave_critical_section(flags);
return ret;
}
/****************************************************************************
* Name: tc_worker
****************************************************************************/
static void tc_worker(void *arg)
{
struct tc_dev_s *priv = (struct tc_dev_s *)arg;
uint32_t delay = TC_PENUP_POLL_TICKS;
uint16_t value;
uint16_t newx = 0;
int16_t xdiff;
int16_t ydiff;
DEBUGASSERT(priv != NULL);
/* Perform the next action based on the state of the conversions */
switch (priv->state)
{
/* The touchscreen is IDLE and we are ready to begin the next sample */
case TC_READY:
{
/* Select DRIVE for Y sampling */
/* Configure XL, XR with drive voltages and disable YU drive. Note
* that this is configuring the DRIVEA and DRIVEB outputs to enable
* the on-board transistor drive logic to energize the touch panel.
*/
*((uint32_t *)LCD_TP_PORT_SETRESET) = LCD_SAMPY_BITS;
/* Allow time for the Y DRIVE to settle */
priv->resamplecount = 0;
priv->sampcount = 0;
priv->value = 0;
priv->state = TC_READY_SETTLE;
delay = TC_SETTLE_TICKS;
}
break;
case TC_READY_SETTLE:
{
/* Start Y sampling */
tc_y_sample();
/* Allow time for the Y pend down sampling */
priv->state = TC_YPENDOWN;
delay = TC_SAMPLE_TICKS;
}
break;
/* The Y sampling time has elapsed and the Y value should be ready
* for conversion
*/
case TC_YPENDOWN:
{
/* Convert the Y sample value */
value = tc_adc_read_sample();
/* A converted value at the minimum would mean that there is no touch
* and that the sampling period is complete.
*/
if (!tc_valid_sample(value))
{
priv->state = TC_PENUP;
}
else
{
/* Allow time for touch inputs to stabilize */
priv->state = TC_DEBOUNCE;
delay = TC_DEBOUNCE_TICKS;
}
}
break;
/* The debounce time period has elapsed and we are ready to re-sample
* the touchscreen.
*/
case TC_RESAMPLE:
{
/* Select DRIVE for Y sampling */
/* Configure XL, XR with drive voltages and disable YU drive. Note
* that this is configuring the DRIVEA and DRIVEB outputs to enable
* the on-board transistor drive logic to energize the touch panel.
*/
*((uint32_t *)LCD_TP_PORT_SETRESET) = LCD_SAMPY_BITS;
/* Allow time for the Y DRIVE to settle */
priv->state = TC_DEBOUNCE;
delay = TC_SETTLE_TICKS;
}
break;
case TC_DEBOUNCE:
{
/* (Re-)start Y sampling */
tc_y_sample();
/* Allow time for the Y sampling */
priv->state = TC_YSAMPLE;
delay = TC_SAMPLE_TICKS;
}
break;
/* The Y sampling period has elapsed and we are ready to perform the
* conversion.
*/
case TC_YSAMPLE: /* Allowing time for the Y sampling */
{
/* Read the Y axis position */
value = tc_adc_read_sample();
/* A converted value at the minimum would mean that we lost the
* contact before all of the conversions were completed. At
* converted value at the maximum value is probably bad too.
*/
if (!tc_valid_sample(value))
{
#ifdef CONFIG_TOUCHSCREEN_RESAMPLE
priv->state = TC_RESAMPLE;
delay = TC_RESAMPLE_TICKS;
#else
priv->state = TC_PENUP;
#endif
}
else
{
value = MAX_ADC - value;
priv->value += value;
if (++priv->sampcount < CONFIG_TOUCHSCREEN_AVG_SAMPLES)
{
priv->state = TC_READY_SETTLE;
delay = 1;
break;
}
priv->newy = value / CONFIG_TOUCHSCREEN_AVG_SAMPLES;
priv->value = 0;
priv->sampcount = 0;
iinfo("Y=%d\n", priv->newy);
/* Configure YU and YD with drive voltages and disable XR drive.
* Note that this is configuring the DRIVEA and DRIVEB outputs
* to enable the on-board transistor drive logic to energize the
* touch panel.
*/
*((uint32_t *)LCD_TP_PORT_SETRESET) = LCD_SAMPX_BITS;
/* Allow time for the X sampling */
priv->state = TC_XSETTLE;
delay = TC_SETTLE_TICKS;
}
}
break;
case TC_XRESAMPLE: /* Perform X resampling */
{
if (priv->resamplecount-- == 0)
{
priv->state = TC_PENUP;
break;
}
}
case TC_XSETTLE: /* Allowing time X to settle after changing DRIVE */
{
/* The X Drive settling time has elaspsed and it's time to start
* the conversion
*/
/* Start X sampling */
tc_x_sample();
/* Allow time for the X sampling */
priv->state = TC_XSAMPLE;
delay = TC_SAMPLE_TICKS;
}
break;
case TC_XSAMPLE: /* Allowing time for the X sampling */
{
/* Read the converted X axis position */
value = tc_adc_read_sample();
/* A converted value at the minimum would mean that we lost the
* contact before all of the conversions were completed. At
* converted value at the maximum value is probably bad too.
*/
if (!tc_valid_sample(value))
{
#ifdef CONFIG_TOUCHSCREEN_RESAMPLE
priv->state = TC_XRESAMPLE;
if (priv->resamplecount == 0)
priv->resamplecount = 1;
delay = TC_RESAMPLE_TICKS;
#else
priv->state = TC_PENUP;
#endif
}
else
{
/* Calculate the X axis position */
priv->value += value;
if (++priv->sampcount < CONFIG_TOUCHSCREEN_AVG_SAMPLES)
{
priv->state = TC_XSETTLE;
delay = 1;
break;
}
newx = value / CONFIG_TOUCHSCREEN_AVG_SAMPLES;
iinfo("X=%d\n", newx);
/* Samples are available */
priv->state = TC_PENDOWN;
}
}
break;
}
/* Check for terminal conditions.. */
/* Check if the sampling resulted in a pen up decision. If so, we need to
* handle the change from pen down to pen up.
*/
if (priv->state == TC_PENUP)
{
/* Ignore if the pen was already down (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)
{
/* The pen is up. We know from the above 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;
/* Indicate the availability of new sample data for this ID */
priv->sample.id = priv->id;
priv->penchange = true;
/* Notify any waiters that new touchscreen data is available */
iinfo("1:X=%d, Y=%d\n", priv->sample.x, priv->sample.y);
tc_notify(priv);
}
/* Set up for the next poll */
priv->sample.valid = false;
priv->state = TC_READY;
delay = TC_PENUP_POLL_TICKS;
}
/* Check if the sampling resulted in a pen down decision. */
else if (priv->state == TC_PENDOWN)
{
/* 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)
*/
if (priv->sample.contact != CONTACT_UP)
{
/* 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.
*/
xdiff = (int16_t)priv->sample.x - (int16_t)newx;
if (xdiff < 0)
{
xdiff = -xdiff;
}
ydiff = (int16_t)priv->sample.y - (int16_t)priv->newy;
if (ydiff < 0)
{
ydiff = -ydiff;
}
if (xdiff >= CONFIG_TOUCHSCREEN_THRESHX ||
ydiff >= CONFIG_TOUCHSCREEN_THRESHY)
{
/* There is some change above the threshold...
* Report the change.
*/
#ifdef CONFIG_LCD_LANDSCAPE
priv->sample.x = MAX_ADC - priv->newy;
priv->sample.y = newx;
#else
priv->sample.x = newx;
priv->sample.y = priv->newy;
#endif
priv->sample.valid = true;
/* If this is the first (acknowledged) penddown report, then
* report this as the 1st 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 nes touchscreen data is available */
iinfo("2:X=%d, Y=%d\n", priv->sample.x, priv->sample.y);
tc_notify(priv);
}
}
/* Set up for the next poll */
priv->state = TC_READY;
delay = TC_PENDOWN_POLL_TICKS;
}
/* Set up the next sample event */
work_queue(HPWORK, &priv->work, tc_worker, priv, delay);
}
/****************************************************************************
* Name: tc_open
****************************************************************************/
static int tc_open(struct file *filep)
{
#ifdef CONFIG_TOUCHSCREEN_REFCNT
struct inode *inode;
struct tc_dev_s *priv;
uint8_t tmp;
int ret;
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Get exclusive access to the driver data structure */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
/* Increment the reference count */
tmp = priv->crefs + 1;
if (tmp == 0)
{
/* More than 255 opens; uint8_t overflows to zero */
ret = -EMFILE;
goto errout_with_lock;
}
/* When the reference increments to 1, this is the first open event
* on the driver.. and an opportunity to do any one-time initialization.
*/
/* Save the new open count on success */
priv->crefs = tmp;
errout_with_lock:
nxmutex_unlock(&priv->devlock);
return ret;
#else
return OK;
#endif
}
/****************************************************************************
* Name: tc_close
****************************************************************************/
static int tc_close(struct file *filep)
{
#ifdef CONFIG_TOUCHSCREEN_REFCNT
struct inode *inode;
struct tc_dev_s *priv;
int ret;
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Get exclusive access to the driver data structure */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
/* Decrement the reference count unless it would decrement a negative
* value. When the count decrements to zero, there are no further
* open references to the driver.
*/
if (priv->crefs >= 1)
{
priv->crefs--;
}
nxmutex_unlock(&priv->devlock);
#endif
return OK;
}
/****************************************************************************
* Name: tc_read
****************************************************************************/
static ssize_t tc_read(struct file *filep, char *buffer, size_t len)
{
struct inode *inode;
struct tc_dev_s *priv;
struct touch_sample_s *report;
struct tc_sample_s sample;
int ret;
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Verify that the caller has provided a buffer large enough to receive
* the touch data.
*/
if (len < SIZEOF_TOUCH_SAMPLE_S(1))
{
/* We could provide logic to break up a touch report into segments and
* handle smaller reads... but why?
*/
return -ENOSYS;
}
/* Get exclusive access to the driver data structure */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
/* Try to read sample data. */
ret = tc_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 = tc_waitsample(priv, &sample);
if (ret < 0)
{
/* We might have been awakened by a signal */
goto errout;
}
}
/* In any event, we now have sampled touchscreen data that we can report
* to the caller.
*/
report = (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 | 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;
}
}
ret = SIZEOF_TOUCH_SAMPLE_S(1);
errout:
nxmutex_unlock(&priv->devlock);
return ret;
}
/****************************************************************************
* Name: tc_ioctl
****************************************************************************/
static int tc_ioctl(struct file *filep, int cmd, unsigned long arg)
{
#if 1
iinfo("cmd: %d arg: %ld\n", cmd, arg);
return -ENOTTY; /* None yet supported */
#else
struct inode *inode;
struct tc_dev_s *priv;
int ret;
iinfo("cmd: %d arg: %ld\n", cmd, arg);
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Get exclusive access to the driver data structure */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
/* Process the IOCTL by command */
switch (cmd)
{
/* ADD IOCTL COMMAND CASES HERE */
default:
ret = -ENOTTY;
break;
}
nxmutex_unlock(&priv->devlock);
return ret;
#endif
}
/****************************************************************************
* Name: tc_poll
****************************************************************************/
static int tc_poll(struct file *filep, struct pollfd *fds, bool setup)
{
struct inode *inode;
struct tc_dev_s *priv;
int ret;
int i;
iinfo("setup: %d\n", (int)setup);
DEBUGASSERT(fds);
inode = filep->f_inode;
DEBUGASSERT(inode->i_private);
priv = inode->i_private;
/* Are we setting up the poll? Or tearing it down? */
ret = nxmutex_lock(&priv->devlock);
if (ret < 0)
{
return ret;
}
if (setup)
{
/* Ignore waits that do not include POLLIN */
if ((fds->events & POLLIN) == 0)
{
ierr("ERROR: Missing POLLIN: revents: %08" PRIx32 "\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_TOUCHSCREEN_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_TOUCHSCREEN_NPOLLWAITERS)
{
ierr("ERROR: No available 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)
{
poll_notify(&fds, 1, POLLIN);
}
}
else if (fds->priv)
{
/* This is a request to tear down the poll. */
struct pollfd **slot = (struct pollfd **)fds->priv;
DEBUGASSERT(slot != NULL);
/* Remove all memory of the poll setup */
*slot = NULL;
fds->priv = NULL;
}
errout:
nxmutex_unlock(&priv->devlock);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: stm32_tsc_setup
*
* Description:
* This function is called by board-bringup logic to configure the
* touchscreen device. This function will register the driver as
* /dev/inputN where N is the minor device number.
*
* Input Parameters:
* 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 stm32_tsc_setup(int minor)
{
struct tc_dev_s *priv;
char devname[DEV_NAMELEN];
#ifdef CONFIG_TOUCHSCREEN_MULTIPLE
irqstate_t flags;
#endif
int ret;
iinfo("minor: %d\n", minor);
DEBUGASSERT(minor >= 0 && minor < 100);
/* If we only have one touchscreen, check if we already did init */
#ifndef CONFIG_TOUCHSCREEN_MULTIPLE
if (g_touchinitdone)
{
return OK;
}
#endif
/* Configure the touchscreen DRIVEA and DRIVEB pins for output */
stm32_configgpio(GPIO_TP_DRIVEA);
stm32_configgpio(GPIO_TP_DRIVEB);
/* Configure Analog inputs for sampling X and Y coordinates */
stm32_configgpio(GPIO_TP_XL);
stm32_configgpio(GPIO_TP_YD);
tc_adc_init();
/* Create and initialize a touchscreen device driver instance */
#ifndef CONFIG_TOUCHSCREEN_MULTIPLE
priv = &g_touchscreen;
#else
priv = kmm_malloc(sizeof(struct tc_dev_s));
if (!priv)
{
ierr("ERROR: kmm_malloc(%d) failed\n", sizeof(struct tc_dev_s));
return -ENOMEM;
}
#endif
/* Initialize the touchscreen device driver instance */
memset(priv, 0, sizeof(struct tc_dev_s));
nxmutex_init(&priv->devlock); /* Initialize device structure mutex */
nxsem_init(&priv->waitsem, 0, 0); /* Initialize pen event wait semaphore */
/* Register the device as an input device */
snprintf(devname, sizeof(devname), DEV_FORMAT, minor);
iinfo("Registering %s\n", devname);
ret = register_driver(devname, &g_tc_fops, 0666, priv);
if (ret < 0)
{
ierr("ERROR: register_driver() failed: %d\n", ret);
goto errout_with_priv;
}
/* Schedule work to perform the initial sampling and to set the data
* availability conditions.
*/
priv->state = TC_READY;
ret = work_queue(HPWORK, &priv->work, tc_worker, priv, 0);
if (ret != 0)
{
ierr("ERROR: Failed to queue work: %d\n", ret);
goto errout_with_priv;
}
/* And return success (?) */
#ifndef CONFIG_TOUCHSCREEN_MULTIPLE
g_touchinitdone = true;
#endif
return OK;
errout_with_priv:
nxmutex_destroy(&priv->devlock);
nxsem_destroy(&priv->waitsem);
#ifdef CONFIG_TOUCHSCREEN_MULTIPLE
kmm_free(priv);
#endif
return ret;
}
#endif /* CONFIG_INPUT */