WIPHEADmaster

1 files changed, 130 insertions, 0 deletions

diff --git a/sd.c b/sd.c
new file mode 100644
index 0000000..78eb137
--- /dev/null
+++ b/sd.c
@@ -0,0 +1,130 @@
+#include "sd.h"
+#include "spi.h"
+#include "util.h"
+
+static uint8_t sd_is_block_device = 0;
+
+uint8_t sd_send_command_util(uint8_t cmd, uint32_t data) {
+	uint8_t i;
+	uint8_t x = 0x01;
+	
+	if (cmd == SD_GO_IDLE_STATE)
+		x = 0x95; /* CRC */
+	else if (cmd == SD_SEND_IF_COND)
+		x = 0x87; /* CRC */
+
+	cmd |= 0x40;
+
+	SD_DESELECT();
+	spi_tx(0xff);
+	SD_SELECT();
+	spi_tx(0xff);
+
+	spi_tx(cmd);
+	spi_tx((uint8_t) (data >> 24));
+	spi_tx((uint8_t) (data >> 16));
+	spi_tx((uint8_t) (data >> 8));
+	spi_tx((uint8_t) (data));
+	spi_tx(x);
+
+	i = 10;
+	do {
+		x = spi_rx();
+	} while ((x & 0x80) && --i);
+
+	return x;
+}
+
+uint8_t sd_send_command(uint8_t cmd, uint32_t data) {
+	if (cmd & 0x80) {
+		uint8_t res = sd_send_command_util(SD_APP_CMD, 0);
+		if (res > 1)
+			return res;
+		cmd &= 0x7f;
+	}
+	return sd_send_command_util(cmd, data);
+}
+
+void sd_wait(void) {
+	uint8_t resp;
+	uint8_t i = 255;
+	do {
+		resp = sd_send_command(SD_SEND_OP_COND, 0);
+	} while (resp != 0 && --i);
+}
+
+char sd_init(void) {
+	uint8_t i;
+	uint16_t tmr;
+	
+	spi_init();
+
+	SD_CHIP_SELECT_TRIS = 0;
+
+	SD_SELECT();
+	for (i = 10; i; i--)
+		delay_100us();
+	SD_DESELECT();
+
+	for (i = 0; i < 20; i++)
+		spi_tx(0xff);
+
+	SD_SELECT();
+	tmr = 1000;
+	do {
+		for (i = 10; i; i--)
+			delay_100us();
+		i = sd_send_command(SD_GO_IDLE_STATE, 0);
+	} while (--tmr && i != 1);
+
+	if (sd_send_command(SD_SEND_IF_COND, 0x1aa) == 1) {
+		/* SD v2 */
+		uint8_t ocr[4];
+		ocr[0] = spi_rx();
+		ocr[1] = spi_rx();
+		ocr[2] = spi_rx();
+		ocr[3] = spi_rx();
+
+#ifdef DEBUG
+		printf("SD v2 %x:%x:%x:%x\r\n", ocr[0], ocr[1], ocr[2], ocr[3]);
+#endif
+
+		if (ocr[2] == 0x01 && ocr[3] == 0xaa) {
+			tmr = 10000;
+			do {
+				delay_100us();
+				i = sd_send_command(SD_OP_COND_SDC, 1UL << 30);
+			} while (--tmr && i);
+
+#ifdef DEBUG
+			printf("Done %u %u\r\n", tmr, i);
+#endif
+
+			i = sd_send_command(SD_READ_OCR, 0);
+
+			if (tmr && i == 0) {
+				ocr[0] = spi_rx();
+				ocr[1] = spi_rx();
+				ocr[2] = spi_rx();
+				ocr[3] = spi_rx();
+
+#ifdef DEBUG
+				printf("OCR: %x:%x:%x:%x\r\n", ocr[0], ocr[1], ocr[2], ocr[3]);
+#endif
+
+				if (ocr[0] & 0x40)
+					sd_is_block_device = 1;
+			}
+		}
+	} else {
+		/* SD v1 */
+#ifdef DEBUG
+		printf("SD v1\r\n");
+#endif
+	}
+
+	SD_DESELECT();
+	spi_rx();
+
+	return 0;
+}