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-rw-r--r--drivers/touchpad/XPT2046/touchpad_lld.c155
-rw-r--r--include/touchpad_lld.h65
2 files changed, 173 insertions, 47 deletions
diff --git a/drivers/touchpad/XPT2046/touchpad_lld.c b/drivers/touchpad/XPT2046/touchpad_lld.c
index 24afcab4..16e4db79 100644
--- a/drivers/touchpad/XPT2046/touchpad_lld.c
+++ b/drivers/touchpad/XPT2046/touchpad_lld.c
@@ -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;
+
+#if defined(SPI_USE_MUTUAL_EXCLUSION)
+ spiAcquireBus(tpDriver->spip);
+#endif
+
+ TOUCHPAD_SPI_PROLOGUE();
+ palClearPad(tpDriver->spicfg->ssport, tpDriver->spicfg->sspad);
+
+ /* 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);
+ }
- txbuf[0] = 0xd0;
- TP_CS_LOW;
- spiSend(&SPID1, 1, txbuf);
- spiReceive(&SPID1, 2, rxbuf);
- TP_CS_HIGH;
+ /* Switch on PENIRQ once again - perform a dummy read */
+ tp_lld_read_value(0xD0);
- x = rxbuf[0] << 4;
- x |= rxbuf[1] >> 4;
+ palSetPad(tpDriver->spicfg->ssport, tpDriver->spicfg->sspad);
+ TOUCHPAD_SPI_EPILOGUE();
- return x;
+#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;
+
+#if defined(SPI_USE_MUTUAL_EXCLUSION)
+ spiAcquireBus(tpDriver->spip);
+#endif
+
+ TOUCHPAD_SPI_PROLOGUE();
+ palClearPad(tpDriver->spicfg->ssport, tpDriver->spicfg->sspad);
- txbuf[0] = 0x90;
- TP_CS_LOW;
- spiSend(&SPID1, 1, txbuf);
- spiReceive(&SPID1, 2, rxbuf);
- TP_CS_HIGH;
+ /* 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
- y = rxbuf[0] << 4;
- y |= rxbuf[1] >> 4;
+ /* Find the median - use selection sort */
+ tp_lld_filter();
- return y;
+ return sampleBuf[3];
}
/* ---- Optional Routines ---- */
@@ -137,7 +228,7 @@ uint16_t tp_lld_read_y(void) {
* @notapi
*/
uint8_t tp_lld_irq(void) {
- return (!palReadPad(TP_IRQ_PORT, TP_IRQ));
+ return (!palReadPad(tpDriver->tpIRQPort, tpDriver->tpIRQPin));
}
#endif
diff --git a/include/touchpad_lld.h b/include/touchpad_lld.h
index 45a561d3..a3a7489c 100644
--- a/include/touchpad_lld.h
+++ b/include/touchpad_lld.h
@@ -49,41 +49,76 @@
#define TOUCHPAD_HAS_PRESSURE FALSE
#endif
+#ifndef TOUCHPAD_SPI_PROLOGUE
+ #define TOUCHPAD_SPI_PROLOGUE()
+#endif
+
+#ifndef TOUCHPAD_SPI_EPILOGUE
+ #define TOUCHPAD_SPI_EPILOGUE()
+#endif
+
/*===========================================================================*/
/* Driver types. */
/*===========================================================================*/
-typedef struct TOUCHPADDriver TOUCHPADDriver;
+typedef struct _TOUCHPADDriver TOUCHPADDriver;
/**
* @brief Structure representing a Touchpad driver.
*/
-struct TOUCHPADDriver {
- /*
- * @brief Pointer to SPI driver.
- */
- SPIDriver *spid;
-
- /*
- * @brief SPI configuration.
- */
- SPIConfig *spicfg;
+struct _TOUCHPADDriver {
+ /*
+ * @brief Pointer to SPI driver.
+ * @note SPI driver must be enabled in mcuconf.h and halconf.h
+ */
+ SPIDriver *spip;
+
+ /*
+ * @brief Pointer to the SPI configuration structure.
+ * @note The lowest possible speed ~ 1-2MHz is to be used, otherwise
+ * will result in a lot of noise
+ */
+ const SPIConfig *spicfg;
+
+ /*
+ * @brief Touchscreen controller TPIRQ pin GPIO port
+ */
+ ioportid_t tpIRQPort;
+
+ /*
+ * @brief Touchscreen controller TPIRQ GPIO pin
+ * @note The interface is polled as of now, interrupt support is
+ * to be implemented in the future.
+ */
+ ioportmask_t tpIRQPin;
+
+ /*
+ * @brief Initialize the SPI with the configuration struct given or not
+ * If TRUE, spiStart is called by the init, otherwise not
+ * @note This is provided in such a case when SPI port is being shared
+ * across multiple peripherals, so not to disturb the SPI bus.
+ * You can use TOUCHPAD_SPI_PROLOGUE() and TOUCHPAD_SPI_EPILOGUE()
+ * macros to change the SPI configuration or speed before and
+ * after using the touchpad. An example case would be sharing the
+ * bus with a fast flash memory chip.
+ */
+ bool_t direct_init;
};
+
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
-#if !defined(__DOXYGEN__)
- extern TOUCHPADDriver Touchpad;
-#endif
#ifdef __cplusplus
extern "C" {
#endif
/* Core functions */
- void tp_lld_init(TOUCHPADDriver *tp);
+ void tp_lld_init(const TOUCHPADDriver *tp);
+
+ uint16_t tp_lld_read_value(uint8_t cmd);
uint16_t tp_lld_read_x(void);
uint16_t tp_lld_read_y(void);
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-11 19:58:41 +0000