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ADS7843 update

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Same changes as the XPT2046
This commit is contained in:
Kumar Abhishek 2012-08-16 15:40:48 +05:30
parent a41a5911e5
commit 0b8c95ab20
1 changed files with 237 additions and 146 deletions
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157
drivers/touchpad/ADS7843/touchpad_lld.c
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@ -36,9 +36,6 @@
/* Driver local definitions. */
/*===========================================================================*/
#define TP_CS_HIGH palSetPad(TP_CS_PORT, TP_CS)
#define TP_CS_LOW palClearPad(TP_CS_PORT, TP_CS)
#ifdef UNUSED
#elif defined(__GNUC__)
# define UNUSED(x) UNUSED_ ## x __attribute__((unused))
@ -52,13 +49,15 @@
/* Driver exported variables. */
/*===========================================================================*/
#if !defined(__DOXYGEN__)
TOUCHPADDriver Touchpad;
#endif
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
#if !defined(__DOXYGEN__)
/* Local copy of the current touchpad driver */
static const TOUCHPADDriver *tpDriver;
static uint16_t sampleBuf[7];
#endif
/*===========================================================================*/
/* Driver local functions. */
@ -79,30 +78,104 @@
*
* @notapi
*/
void tp_lld_init(TOUCHPADDriver *tp) {
spiStart(tp->spid, tp->spicfg);
void tp_lld_init(const TOUCHPADDriver *tp) {
tpDriver=tp;
if (tpDriver->direct_init)
spiStart(tpDriver->spip, tpDriver->spicfg);
}
/**
* @brief Reads a conversion from the touchpad
*
* @param[in] cmd The command bits to send to the touchpad
*
* @return The read value 12-bit right-justified
*
* @note This function only reads data, it is assumed that the pins are
* configured properly and the bus has been acquired beforehand
*
* @notapi
*/
uint16_t tp_lld_read_value(uint8_t cmd) {
static uint8_t txbuf[3]={0};
static uint8_t rxbuf[3]={0};
uint16_t ret;
txbuf[0]=cmd;
spiExchange(tpDriver->spip, 3, txbuf, rxbuf);
ret = (rxbuf[1] << 5) | (rxbuf[2] >> 3);
return ret;
}
/**
* @brief 7-point median filtering code for touchpad samples
*
* @note This is an internally used routine only.
*
* @notapi
*/
static void tp_lld_filter(void) {
uint16_t temp;
int i,j;
for (i=0; i<4; i++) {
for (j=i; j<7; j++) {
if (sampleBuf[i] > sampleBuf[j]) {
/* Swap the values */
temp=sampleBuf[i];
sampleBuf[i]=sampleBuf[j];
sampleBuf[j]=temp;
}
}
}
}
/**
* @brief Reads out the X direction.
*
* @note The samples are median filtered for greater noise reduction
*
* @notapi
*/
uint16_t tp_lld_read_x(void) {
uint8_t txbuf[1];
uint8_t rxbuf[2];
uint16_t x;
int i;
txbuf[0] = 0xd0;
TP_CS_LOW;
spiSend(&SPID1, 1, txbuf);
spiReceive(&SPID1, 2, rxbuf);
TP_CS_HIGH;
#if defined(SPI_USE_MUTUAL_EXCLUSION)
spiAcquireBus(tpDriver->spip);
#endif
x = rxbuf[0] << 4;
x |= rxbuf[1] >> 4;
TOUCHPAD_SPI_PROLOGUE();
palClearPad(tpDriver->spicfg->ssport, tpDriver->spicfg->sspad);
return x;
/* Discard the first conversion - very noisy and keep the ADC on hereafter
* till we are done with the sampling. Note that PENIRQ is disabled.
*/
tp_lld_read_value(0xD1);
for (i=0;i<7;i++) {
sampleBuf[i]=tp_lld_read_value(0xD1);
}
/* Switch on PENIRQ once again - perform a dummy read */
tp_lld_read_value(0xD0);
palSetPad(tpDriver->spicfg->ssport, tpDriver->spicfg->sspad);
TOUCHPAD_SPI_EPILOGUE();
#if defined(SPI_USE_MUTUAL_EXCLUSION)
spiReleaseBus(tpDriver->spip);
#endif
/* Find the median - use selection sort */
tp_lld_filter();
return sampleBuf[3];
}
/*
@ -111,20 +184,38 @@ uint16_t tp_lld_read_x(void) {
* @notapi
*/
uint16_t tp_lld_read_y(void) {
uint8_t txbuf[1];
uint8_t rxbuf[2];
uint16_t y;
int i;
txbuf[0] = 0x90;
TP_CS_LOW;
spiSend(&SPID1, 1, txbuf);
spiReceive(&SPID1, 2, rxbuf);
TP_CS_HIGH;
#if defined(SPI_USE_MUTUAL_EXCLUSION)
spiAcquireBus(tpDriver->spip);
#endif
y = rxbuf[0] << 4;
y |= rxbuf[1] >> 4;
TOUCHPAD_SPI_PROLOGUE();
palClearPad(tpDriver->spicfg->ssport, tpDriver->spicfg->sspad);
return y;
/* Discard the first conversion - very noisy and keep the ADC on hereafter
* till we are done with the sampling. Note that PENIRQ is disabled.
*/
tp_lld_read_value(0x91);
for (i=0;i<7;i++) {
sampleBuf[i]=tp_lld_read_value(0x91);
}
/* Switch on PENIRQ once again - perform a dummy read */
tp_lld_read_value(0x90);
palSetPad(tpDriver->spicfg->ssport, tpDriver->spicfg->sspad);
TOUCHPAD_SPI_EPILOGUE();
#ifdef SPI_USE_MUTUAL_EXCLUSION
spiReleaseBus(tpDriver->spip);
#endif
/* Find the median - use selection sort */
tp_lld_filter();
return sampleBuf[3];
}
/* ---- Optional Routines ---- */
@ -134,10 +225,10 @@ uint16_t tp_lld_read_y(void) {
*
* @return 1 if pressed / 0 if not pressed
*
* @noapi
* @notapi
*/
uint8_t tp_lld_irq(void) {
return (!palReadPad(TP_IRQ_PORT, TP_IRQ));
return (!palReadPad(tpDriver->tpIRQPort, tpDriver->tpIRQPin));
}
#endif