From 631204a1feffa8cf3795060370b14dfb9f53f533 Mon Sep 17 00:00:00 2001
From: Camil Staps
Date: Tue, 31 Jan 2017 23:15:28 +0100
Subject: WIP

---
 diskio.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 diskio.c

(limited to 'diskio.c')

diff --git a/diskio.c b/diskio.c
new file mode 100644
index 0000000..ba12e4a
--- /dev/null
+++ b/diskio.c
@@ -0,0 +1,109 @@
+/*-----------------------------------------------------------------------*/
+/* Low level disk I/O module skeleton for Petit FatFs (C)ChaN, 2014      */
+/*-----------------------------------------------------------------------*/
+
+#include "diskio.h"
+#include "sd.h"
+#include "spi.h"
+#include "util.h"
+
+static void spi_rx_multi(BYTE *buff, UINT cnt) {
+	do {
+		*buff++ = spi_rx();
+	} while (--cnt);
+}
+
+static int rcv_datablock(BYTE *buff, UINT btr) {
+	uint8_t token;
+	uint16_t count = 10000;
+
+	do token = spi_rx(); while (token == 0xff && --count);
+
+	if (token != 0xfe)
+		return 0;
+
+	spi_rx_multi(buff, btr);
+	spi_rx();
+	spi_rx();
+
+	return 1;
+}
+
+/*-----------------------------------------------------------------------*/
+/* Initialize Disk Drive                                                 */
+/*-----------------------------------------------------------------------*/
+
+static DSTATUS status = STA_NODISK;
+
+DSTATUS disk_status(BYTE pdrv) {
+	if (pdrv)
+		return STA_NOINIT;
+	return status;
+}
+
+DSTATUS disk_initialize (BYTE pdrv)
+{
+	uint8_t n, cmd;
+	uint32_t tmr;
+
+	if (!status)
+		return 0;
+
+#ifdef DEBUG
+	printf("Init SD\r\n");
+#endif
+
+	if (sd_init())
+		return STA_NOINIT;
+
+#ifdef DEBUG
+	printf("Done disk_initialize\r\n");
+#endif
+
+	status = 0;
+
+	return 0;
+}
+
+
+
+/*-----------------------------------------------------------------------*/
+/* Read Partial Sector                                                   */
+/*-----------------------------------------------------------------------*/
+
+DRESULT disk_read (
+	BYTE pdrv,      /* Physical drive number (0) */
+	BYTE* buff,		/* Pointer to the destination object */
+	DWORD sector,	/* Sector number (LBA) */
+	UINT count		/* Byte count (bit15:destination) */
+)
+{
+	DRESULT res = RES_ERROR;
+	BYTE rc;
+	UINT bc;
+
+	if (pdrv || !count)
+		return RES_PARERR;
+	if (status && STA_NOINIT)
+		return RES_NOTRDY;
+
+	sector *= 512;
+
+	if (count == 1) {
+		if ((sd_send_command(SD_READ_SINGLE_BLOCK, sector) == 0)
+				&& rcv_datablock(buff, 512))
+			count = 0;
+	} else if (sd_send_command(SD_READ_MULTIPLE_BLOCK, sector) == 0) {
+		do {
+			if (!rcv_datablock(buff, 512))
+				break;
+			buff += 512;
+		} while (--count);
+		sd_send_command(SD_STOP_TRANSMISSION, 0);
+	}
+
+	SD_DESELECT();
+	spi_rx();
+
+	return count ? RES_ERROR : RES_OK;
+}
-- 
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