tornado/fw/: add MMC driver (WIP, based on Mass Storage for V-USB by "lleeloo")

tornado/fw/Makefile

@@ -31,7 +31,7 @@ OBJCOPY = $(AVR_PREFIX)objcopy
 #OBJDUMP = $(AVR_PREFIX)objdump
 SIZE = $(AVR_PREFIX)size
 
-OBJS = $(NAME).o accel.o led.o $(COMMON_OBJS)
+OBJS = $(NAME).o accel.o led.o mmc.o mmc-hw.o $(COMMON_OBJS)
 BOOT_OBJS = boot.o $(COMMON_OBJS)
 COMMON_OBJS =
 

tornado/fw/mmc-hw.c

@@ -0,0 +1,55 @@
+/*
+ * fw/mmc-hw.c - MMC hardware interface
+ *
+ * Written 2012 by Werner Almesberger
+ * Copyright 2012 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#include <stdint.h>
+
+#include "io.h"
+#include "mmc-hw.h"
+
+
+void mmc_select(void)
+{
+//	CS = 0;
+}
+
+void mmc_deselect(void)
+{
+//	CS = 1;
+}
+
+
+uint8_t mmc_recv(void)
+{
+//	MSB first
+	return 0;
+}
+
+
+void mmc_send(uint8_t v)
+{
+//	MSB first
+}
+
+
+void mmc_activate(void)
+{
+//	set pull-ups
+//	VDD = 1;
+}
+
+
+void mmc_deactivate(void)
+{
+//	set directions
+//	VDD = 0;
+}

tornado/fw/mmc-hw.h

@@ -0,0 +1,27 @@
+/*
+ * fw/mmc-hw.h - MMC hardware interface
+ *
+ * Written 2012 by Werner Almesberger
+ * Copyright 2012 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#ifndef MMC_HW_H
+#define MMC_HW_H
+
+#include <stdint.h>
+
+
+void mmc_select(void);
+void mmc_deselect(void);
+uint8_t mmc_recv(void);
+void mmc_send(uint8_t v);
+void mmc_activate(void);
+void mmc_deactivate(void);
+
+#endif /* !MMC_HW_H */

tornado/fw/mmc.c

@@ -0,0 +1,211 @@
+/*
+ * fw/mmc.c - MMC card access
+ *
+ * Written 2012 by Werner Almesberger
+ * Copyright 2012 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+/*
+ * Heavily influenced by the MMC driver in the Mass Storage for V-USB project
+ * by "lleeloo":
+ * http://we.easyelectronics.ru/AVR/usb-fleshka-na-atmega8-i-v-usb-ot-idei-k-gotovomu-ustroystvu.html
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "mmc-hw.h"
+#include "mmc.h"
+
+
+/* Command indices */
+
+enum {
+	MMC_GO_IDLE_STATE	= 0,
+	MMC_SEND_OP_COND	= 1,
+	MMC_SET_BLOCKLEN	= 16,
+	MMC_READ_SINGLE_BLOCK	= 17,
+	MMC_WRITE_BLOCK		= 24,
+};
+
+
+/* Start block tokens */
+
+enum {
+	MMC_START_SINGLE_BLOCK	= 0xfe,
+};
+
+
+static void mmc_begin(void)
+{
+	mmc_select();
+}
+
+
+static void mmc_end(void)
+{
+	mmc_send(0xff);
+	mmc_send(0xff);
+	mmc_deselect();
+	mmc_send(0xff);
+}
+
+static void mmc_command(uint8_t cmd, uint32_t arg)
+{
+	mmc_send(0x40 | cmd);	/* start (0)+transmission(1)+cmd */
+	mmc_send(arg >> 24);
+	mmc_send(arg >> 16);
+	mmc_send(arg >> 8);
+	mmc_send(arg);
+	mmc_send(0x95);		/* crc7+end(1) */
+}
+
+
+static uint8_t mmc_r1(void)
+{
+	uint8_t v, tries = 0xff;
+
+	do v = mmc_read(); 
+	while ((v & 0x80) && --tries);
+	return v;
+}
+
+
+static void mmc_wait(void)
+{
+	uint8_t v, tries = 0xff;
+
+	do {
+		v = mmc_read(); 
+		if (v == MMC_START_SINGLE_BLOCK)
+			return;
+	}
+	while (--tries);
+}
+
+
+bool mmc_begin_read(uint32_t sector)
+{
+	mmc_begin();
+	mmc_command(MMC_READ_SINGLE_BLOCK, sector);
+	if (mmc_r1()) {
+		mmc_end();
+		return 0;
+	} else {
+		mmc_wait();
+		return 1;
+	}
+}
+
+
+uint8_t mmc_read(void)
+{
+	return mmc_recv();
+}
+
+
+bool mmc_end_read(void)
+{
+	mmc_end();
+	return 1;
+}
+
+
+bool mmc_begin_write(uint32_t sector)
+{
+	mmc_begin();
+	mmc_command(MMC_WRITE_BLOCK, sector);
+	if (mmc_r1()) {
+		mmc_end();
+		return 0;
+	} else {
+		mmc_send(0xff);
+		mmc_send(0xff);
+		mmc_send(MMC_START_SINGLE_BLOCK);
+		return 1;
+	}
+}
+
+
+void mmc_write(uint8_t data)
+{
+	mmc_send(data);
+}
+
+
+bool mmc_end_write(void)
+{
+	mmc_send(0xff);
+	mmc_send(0xff);
+	mmc_recv();
+	while (!mmc_recv());
+	mmc_end();
+	return 1;
+}
+
+
+void mmc_off(void)
+{
+	mmc_deactivate();
+}
+
+
+static void send_clock(void)
+{
+	uint8_t i;
+
+	for (i = 0; i != 10; i++)
+		mmc_send(0xff);
+}
+
+
+bool mmc_init(void)
+{
+	uint16_t tries = 0xff;
+	uint8_t res;
+
+	mmc_activate();
+	send_clock();
+	mmc_begin();
+
+	do {
+		mmc_command(MMC_GO_IDLE_STATE, 0);
+		if (mmc_r1() == 0x01)	/* in idle state */
+			break;
+	}
+	while (--tries);
+	mmc_end();
+	if (!tries)
+		return 0;
+
+	send_clock();
+
+	tries = 0x7ff;
+	do {
+		mmc_select();
+		mmc_command(MMC_SEND_OP_COND, 0);
+		res = mmc_r1();
+		mmc_deselect();
+		send_clock();
+	}
+	while (res && --tries);
+
+	mmc_end();
+
+	if (res) {
+		mmc_deactivate();
+		return 0;
+	}
+
+	mmc_begin();
+	mmc_command(MMC_SET_BLOCKLEN, MMC_BLOCK);
+	mmc_r1();
+	mmc_end();
+
+	return 1;
+}

tornado/fw/mmc.h

@@ -0,0 +1,35 @@
+/*
+ * fw/mmc.h - MMC card access
+ *
+ * Written 2012 by Werner Almesberger
+ * Copyright 2012 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#ifndef MMC_H
+#define MMC_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+
+#define	MMC_BLOCK	512
+
+
+bool mmc_begin_read(uint32_t sector);
+uint8_t mmc_read(void);
+bool mmc_end_read(void);
+
+bool mmc_begin_write(uint32_t sector);
+void mmc_write(uint8_t data);
+bool mmc_end_write(void);
+
+void mmc_off(void);
+bool mmc_init(void);
+
+#endif /* !MMC_H */