add submodules and switch

.gitmodules

@@ -0,0 +1,4 @@
+[submodule "creole"]
+	path = creole
+	url = https://software.mcgoron.com/peter/creole
+	branch = upsilon

creole

@@ -0,0 +1 @@
+Subproject commit 945bcd68a54ebf6794fa791545426e5f29644029

firmware/rtl/control_loop/control_loop.v

@@ -38,6 +38,7 @@ module control_loop
 	parameter DAC_SS_WAIT_SIZ = 3
 ) (
 	input clk,
+	output in_loop,
 
 	output dac_mosi,
 	input dac_miso,
@@ -324,6 +325,8 @@ always @ (posedge clk) begin
 	end
 end
 
+assign in_loop = state != INIT_READ_FROM_DAC || running;
+
 always @ (posedge clk) begin
 	case (state)
 	INIT_READ_FROM_DAC: begin

firmware/rtl/spi/spi_switch.v

@@ -0,0 +1,41 @@
+/* This module is a co-operative crossbar for the wires only. Each end
+ * implements its own SPI master.
+ *
+ * This crossbar is entirely controlled by the kernel.
+ */
+module spi_crossbar #(
+	parameter PORTS = 2,
+(
+	input select[PORTS-1:0],
+
+	output mosi,
+	input miso,
+	output sck,
+	output ss,
+
+	input mosi_ports[PORTS-1:0],
+	output miso_ports[PORTS-1:0],
+	input sck_ports[PORTS-1:0],
+	input ss_ports[PORTS-1:0]
+);
+
+/* Avoid using for loops, they might not synthesize correctly.
+   Do things the old, dumb way instead.
+ */
+
+always @(*) begin
+	if (select[1]) begin
+		mosi = mosi_ports[1];
+		miso = miso_ports[1];
+		sck = sck_ports[1];
+		ss = ss_ports[1];
+	end else begin
+		/* Select zeroth slot by default. No latches. */
+		mosi = mosi_ports[0];
+		miso = miso_ports[0];
+		sck = sck_ports[0];
+		ss = ss_ports[0];
+	end
+end
+
+endmodule

software/src/io.c

@@ -1,86 +0,0 @@
-#include <zephyr/zephyr.h>
-#include <zephyr/kernel.h>
-#include <zephyr/logging/log.h>
-
-LOG_MODULE_REGISTER(adc_dac_io);
-
-#include <string.h>
-#define CSR_LOCATIONS
-#include "pin_io.h"
-
-static int32_t
-sign_extend(uint32_t n, unsigned wid)
-{
-	if (n >> (wid - 1))
-		return (int32_t) (~((uint32_t) 0) & n);
-	else
-		return (int32_t) n;
-}
-
-int32_t
-adc_read(size_t num, unsigned wid)
-{
-	if (num >= ADC_MAX) {
-		LOG_ERR("adc_read got bad ADC %zd\n", num);
-		k_fatal_halt(K_ERR_KERNEL_OOPS);
-	}
-	if (wid > 32) {
-		LOG_ERR("adc_read got bad width %u\n", wid);
-		k_fatal_halt(K_ERR_KERNEL_OOPS);
-	}
-
-	*adc_conv[num] = 1;
-	k_sleep(K_NSEC(550));
-	*adc_arm[num] = 1;
-	*adc_conv[num] = 0;
-	// XXX: Guess
-	k_sleep(K_MSEC(40));
-	while (!*adc_finished[num]);
-
-	uint32_t buf = *adc_from_slave[num];
-	*adc_arm[num] = 0;
-	return sign_extend(buf);
-}
-
-uint32_t
-dac_write_raw(size_t n, uint32_t data)
-{
-	if (n >= DAC_MAX) {
-		LOG_ERR("dac_write_raw got bad ADC %d\n", n);
-		k_fatal_halt(K_ERR_KERNEL_OOPS);
-	}
-
-	*dac_to_slave[n] = data;
-	*dac_ss[n] = 1;
-	k_sleep(K_NSEC(20));
-	*dac_arm[n] = 1;
-	// XXX: Guess
-	k_sleep(K_MSEC(50));
-	while (!*dac_finished[num]);
-
-	*dac_ss[n] = 0;
-	uint32_t r = *dac_from_slave[n];
-	*dac_arm[n] = 0;
-	return r;
-}
-
-void
-dac_write_v(size_t n, uint32_t v)
-{
-	dac_write_raw(n, (1 << 20) | (v & 0xFFFFF));
-}
-
-int
-dac_init(size_t n)
-{
-	/* Write to control register. */
-	const uint32_t msg =
-		(1 << 1) // RBUF
-		| (1 << 4) // Binary Offset
-	;
-	dac_write_raw(n, (1 << 21) | msg);
-	// Read from the control register
-	dac_write_raw(n, (1 << 21) | (1 << 23));
-	// Send NOP to read the returned data.
-	return dac_write_raw(n, 0) == msg;
-}

software/src/io.h

@@ -1,7 +0,0 @@
-#pragma once
-
-int32_t adc_read(size_t num, unsigned wid);
-
-uint32_t dac_write_raw(size_t n, uint32_t data);
-void dac_write_v(size_t n, uint32_t v);
-int dac_init(size_t n);

software/src/lsc.h

@@ -1,112 +0,0 @@
-#ifndef LSC
-#define LSC
-#include <stddef.h>
-
-#ifndef LSC_MAXARG
-# define LSC_MAXARG 32
-#endif
-
-#ifndef LSC_MAXBUF
-# define LSC_MAXBUF 1024
-#endif
-
-struct lsc_line {
-	size_t name;
-	char *buf[LSC_MAXARG];
-	size_t len;
-};
-
-struct lsc_parser {
-	int state;
-
-	char intbuf[LSC_MAXBUF];
-	size_t len;
-
-	char *rptr;
-};
-
-enum lsc_r {
-	LSC_MORE,
-	LSC_OVERFLOW,
-	LSC_ARG_OVERFLOW,
-	LSC_INVALID_ARGUMENT,
-	LSC_COMPLETE
-};
-
-void lsc_reset(struct lsc_parser *, char *);
-enum lsc_r lsc_read(struct lsc_parser *,
-                    struct lsc_line *);
-static void lsc_load_ptr(struct lsc_parser *in, char *p) {
-	in->rptr = p;
-}
-
-#endif
-#ifdef LSC_IMPLEMENTATION
-
-enum { LSC_READ, LSC_DISCARD };
-
-static void reset_parse_state(struct lsc_parser *in) {
-	in->state = LSC_READ;
-	in->len = 0;
-}
-
-void lsc_reset(struct lsc_parser *in, char *p) {
-	reset_parse_state(in);
-	in->rptr = p;
-}
-
-static enum lsc_r lsc_parse(struct lsc_parser *in,
-                            struct lsc_line *line) {
-	char *s = in->intbuf;
-	enum lsc_r r = LSC_ARG_OVERFLOW;
-
-	line->name = (*s == ':');
-	line->len = 0;
-
-	while (line->len < LSC_MAXARG) {
-		line->buf[line->len++] = s;
-		for (; *s && *s != '\t'; s++);
-
-		if (!*s) {
-			r = LSC_COMPLETE;
-			break;
-		} else {
-			*s = 0;
-			s++;
-		}
-	}
-
-	reset_parse_state(in);
-	return r;
-}
-
-enum lsc_r lsc_read(struct lsc_parser *psr,
-                    struct lsc_line *line) {
-	char c;
-
-	if (!psr || !psr->rptr || !line)
-		return LSC_INVALID_ARGUMENT;
-
-	while ((c = *psr->rptr)) {
-		psr->rptr++;
-		if (psr->state == LSC_DISCARD) {
-			if (c == '\n') {
-				reset_parse_state(psr);
-				return LSC_OVERFLOW;
-			}
-		} else {
-			switch (c) {
-			case '\n':
-				psr->intbuf[psr->len] = 0;
-				return lsc_parse(psr, line);
-			default:
-				if (psr->len == LSC_MAXBUF)
-					psr->state = LSC_DISCARD;
-				psr->intbuf[psr->len++] = c;
-			}
-		}
-	}
-
-	return LSC_MORE;
-}
-#endif

software/src/main.c

@@ -7,115 +7,8 @@
 #include "sock.h"
 #include "buf.h"
 
-#define LSC_IMPLEMENTATION
-#include "lsc.h"
-
 LOG_MODULE_REGISTER(main);
 
-#define PORT 6626
-
-enum {
-	IDENT,
-	ADC,
-	DAC,
-
-	CL_SETPT,
-	CL_P,
-	CL_I,
-	CL_ARM,
-	CL_ERR,
-	CL_Z,
-	CL_CYCLES,
-	CL_DELAY,
-
-	RASTER_MAX_SAMPLES,
-	RASTER_MAX_LINES,
-	RASTER_SETTLE_TIME,
-	RASTER_DX,
-	RASTER_DY,
-	RASTER_USED_ADCS,
-	RASTER_ARM,
-
-	ARGS_NUM
-};
-
-static int _strcmp(const void *p1, const void *p2) {return strcmp(p1,p2);}
-
-static int
-client_exec(int sock, struct lsc_line *l)
-{
-	static char buf[4096];
-#	define stringify(s) #s
-#	define mkid(s) [s] = stringify(s)
-	static const char *argnames[ARGS_NUM] = {
-		mkid(IDENT),
-		mkid(ADC),
-		mkid(DAC),
-
-		mkid(CL_SETPT),
-		mkid(CL_P),
-		mkid(CL_I),
-		mkid(CL_ARM),
-		mkid(CL_ERR),
-		mkid(CL_Z),
-		mkid(CL_CYCLES),
-		mkid(CL_DELAY),
-
-		mkid(RASTER_MAX_SAMPLES),
-		mkid(RASTER_MAX_LINES),
-		mkid(RASTER_SETTLE_TIME),
-		mkid(RASTER_DX),
-		mkid(RASTER_DY),
-		mkid(RASTER_USED_ADCS),
-		mkid(RASTER_ARM)
-	};
-#	undef mkid
-#	undef stringify
-
-	char **p = bsearch(l->buf[l->name], argnames, ARGS_NUM,
-	                  sizeof(argnames[0]), _strcmp);
-	if (!p) {
-		sock_name_printf(sock, l, buf, sizeof(buf),
-		                 "ERROR\tunknown command\n");
-		return 0;
-	}
-
-	switch (p - argnames) {
-
-	}
-}
-
-static void
-client_parse(int cli)
-{
-	static char buf[LSC_MAXBUF];
-	static struct bufptr bp = {buf, sizeof(buf)};
-	static struct lsc_parser psr = {0};
-	static bool first = true;
-	struct lsc_line l;
-
-	if (first) {
-		lsc_reset(&psr, buf);
-		first = false;
-	}
-
-	switch (lsc_read(&psr, &l)) {
-	case LSC_OVERFLOW:
-		LOG_ERR("client command overflow\n");
-		break;
-	case LSC_OVERFLOW:
-		LOG_ERR("client command argument overflow\n");
-		break;
-	case LSC_INVALID_ARGUMENT:
-		LOG_ERR("programmer misuse");
-		break;
-	case LSC_COMPLETE:
-		// process
-		lsc_reset(&psr, buf);
-		break:
-	}
-}
-
 static void
 process_client(int cli)
 {
@@ -140,7 +33,7 @@ process_client(int cli)
 void
 main(void)
 {
-	int srv = server_init_sock(PORT);
+	int srv = server_init_sock(6626);
 
 	for (;;) {
 		int cli = server_get_client(server_sock);

software/src/sock.c

@@ -4,7 +4,6 @@
 #include <zephyr/kernel.h>
 #include <zephyr/logging/log.h>
 #include "sock.h"
-#include "lsc.h"
 
 LOG_MODULE_REGISTER(sock);
 
@@ -82,22 +81,6 @@ sock_vprintf(int sock, char *buf, int buflen, char *fmt, va_list va)
 	return w;
 }
 
-int
-sock_name_printf(int sock, struct lsc_line *l, char *buf, int buflen, char *fmt, ...)
-{
-	if (l->name) {
-		int r = sock_printf(sock, buf, buflen, "%s\t", l->buf[0]);
-		if (r < 0)
-			return r;
-	}
-
-	va_list va;
-	va_start(va, fmt);
-	int r = sock_vprintf(sock, buf, buflen, fmt, va);
-	va_end(va);
-	return r;
-}
-
 int
 sock_printf(int sock, char *buf, int buflen, char *fmt, ...)
 {

software/src/sock.h

@@ -1,3 +1,7 @@
 #pragma once
+
+/* Initialize server to listen on the port passed as an argument. */
 int server_init_sock(int port);
+
+/* Accept a client and allocate a file descriptor for the client. */
 int server_accept_client(int server);