78k0 spi mode

CMakeLists.txt

@@ -37,6 +37,7 @@ if(FAMILY STREQUAL "rp2040")
     ${CMAKE_CURRENT_SOURCE_DIR}/src/swim/swim_hw.c
     ${CMAKE_CURRENT_SOURCE_DIR}/src/tool78/tool78_hw_helpers.c
     ${CMAKE_CURRENT_SOURCE_DIR}/src/tool78/tool78_hw_test_uart2.c
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/tool78/tool78_hw_78k0_spi.c
     ${CMAKE_CURRENT_SOURCE_DIR}/src/tool78/tool78_hw_78k0_uart2.c
     ${CMAKE_CURRENT_SOURCE_DIR}/src/tool78/tool78_hw_78k0_uart2_extclk.c
     ${CMAKE_CURRENT_SOURCE_DIR}/src/tool78/tool78_hw_78k0r_uart1.c

src/tool78/tool78_hw_78k0_spi.c

@@ -0,0 +1,107 @@
+
+#include <hardware/gpio.h>
+#include <hardware/pio.h>
+#include <pico/time.h>
+#include <pico/timeout_helper.h>
+
+#include "tool78_defs.h"
+#include "tool78_hw_helpers.h"
+
+#include "tool78.pio.h"
+
+#include "tool78_hw.h"
+
+static struct tool78_pio_vars vars;
+
+static int t78k0_spi_xfer(int len, const uint8_t* out, uint8_t* in,
+		int32_t timeout_us) {
+	if (!out && !in) return 0;
+
+	const uint32_t tdr = 12;/*inter-byte delay (us) tDR = 90/8M s */
+
+	bool blockinf = timeout_us < 0;
+	absolute_time_t at = make_timeout_time_us(timeout_us);
+	timeout_state_t ts = {0};
+	check_timeout_fn ct = NULL;
+	if (!blockinf) ct = init_single_timeout_until(&ts, at);
+
+	int i = 0;
+	for (; i < len; ++i) {
+		while (pio_sm_is_tx_fifo_full(PINOUT_TOOL78_PIO, vars.smrx)) {
+			if (!blockinf && ct(&ts)) goto end; // whoops, timeout
+		}
+
+		*(volatile uint8_t*)&PINOUT_TOOL78_PIO->txf[vars.smrx] =
+			out ? out[i] : 0xff;
+
+		while (pio_sm_is_rx_fifo_empty(PINOUT_TOOL78_PIO, vars.smrx)) {
+			if (!blockinf && ct(&ts)) goto end; // whoops, timeout
+		}
+
+		uint8_t v = *(volatile uint8_t*)&PINOUT_TOOL78_PIO->rxf[vars.smrx];
+		if (in) in[i] = v;
+
+		// FIXME: THIS IS NOT HOW TO WAIT BETWEEN TWO BYTES YOU DOOFUS
+		// (ok maybe it might work because of bad reasons, so let's fix this
+		// once it causes problems)
+		if (tdr) busy_wait_us_32(tdr);
+	}
+
+end:
+	return i;
+}
+
+static bool t78k0_spi_init(void) {
+	if (!tool78_hw_init_help(NULL, &tool78_spi_program, &vars)) return false;
+
+	vars.exclusive = false;
+	vars.bitswap = false;
+
+	// extclk between 2 and 20 MHz
+	tool78_entryseq_78k0(tool78k0_spi);
+
+	tool78_spi_program_init(PINOUT_TOOL78_PIO, vars.smrx, vars.rxoff,
+			PINOUT_TOOL78_78K0_CLOCK, PINOUT_TOOL78_78K0_TXMOSI,
+			PINOUT_TOOL78_78K0_RXMISO, 1*1000*1000, true);
+
+	busy_wait_us_32(477768); // tCOM or tR1
+
+	// now a reset command needs to be sent, but we leave that to the upper
+	// (command processing) layer as it has to know about those timings anyway
+
+	return true; // all is well!
+}
+static void t78k0_spi_deinit(void) {
+	tool78_hw_deinit_help(&tool78_spi_program, NULL, &vars);
+
+	tool78_deinit_78k0();
+}
+
+static int t78k0_spi_has_available(void) {
+	int r = 1;
+
+	if (tool78_hw_help_check_overrun(&vars)) r = -r;
+
+	return r;
+}
+
+
+static int t78k0_spi_recv(int len, uint8_t* data, int32_t timeout_us) {
+	return t78k0_spi_xfer(len, NULL, data, timeout_us);
+}
+static int t78k0_spi_send(int len, const uint8_t* data, int32_t timeout_us) {
+	return t78k0_spi_xfer(len, data, NULL, timeout_us);
+}
+
+struct tool78_hw tool78_hw_78k0_spi = {
+	.target = tool78k0_spi,
+
+	.init = t78k0_spi_init,
+	.deinit = t78k0_spi_deinit,
+
+	.has_available = t78k0_spi_has_available,
+
+	.recv = t78k0_spi_recv,
+	.send = t78k0_spi_send
+};
+