Add extcsd write-protect read/write code
This was posted to linux-mmc@ by Johan Rudholm.
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/mmc.h b/mmc.h
new file mode 100644
index 0000000..8540f3d
--- /dev/null
+++ b/mmc.h
@@ -0,0 +1,61 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <asm-generic/int-ll64.h>
+#include <linux/mmc/ioctl.h>
+#include <linux/major.h>
+#include <stdio.h>
+
+#define CHECK(expr, msg, err_stmt) { if (expr) { fprintf(stderr, msg); err_stmt; } }
+
+/* From kernel linux/mmc/mmc.h */
+#define MMC_SWITCH 6 /* ac [31:0] See below R1b */
+#define MMC_SEND_EXT_CSD 8 /* adtc R1 */
+#define MMC_SWITCH_MODE_WRITE_BYTE 0x03 /* Set target to value */
+
+/*
+ * EXT_CSD fields
+ */
+#define EXT_CSD_BOOT_WP 173 /* R/W */
+#define EXT_CSD_PART_SWITCH_TIME 199 /* RO */
+
+/*
+ * EXT_CSD field definitions
+ */
+#define EXT_CSD_CMD_SET_NORMAL (1<<0)
+#define EXT_CSD_BOOT_WP_B_PWR_WP_DIS (0x40)
+#define EXT_CSD_BOOT_WP_B_PERM_WP_DIS (0x10)
+#define EXT_CSD_BOOT_WP_B_PERM_WP_EN (0x04)
+#define EXT_CSD_BOOT_WP_B_PWR_WP_EN (0x01)
+
+/* From kernel linux/mmc/core.h */
+#define MMC_RSP_PRESENT (1 << 0)
+#define MMC_RSP_136 (1 << 1) /* 136 bit response */
+#define MMC_RSP_CRC (1 << 2) /* expect valid crc */
+#define MMC_RSP_BUSY (1 << 3) /* card may send busy */
+#define MMC_RSP_OPCODE (1 << 4) /* response contains opcode */
+
+#define MMC_CMD_AC (0 << 5)
+#define MMC_CMD_ADTC (1 << 5)
+
+#define MMC_RSP_SPI_S1 (1 << 7) /* one status byte */
+#define MMC_RSP_SPI_BUSY (1 << 10) /* card may send busy */
+
+#define MMC_RSP_SPI_R1 (MMC_RSP_SPI_S1)
+#define MMC_RSP_SPI_R1B (MMC_RSP_SPI_S1|MMC_RSP_SPI_BUSY)
+
+#define MMC_RSP_R1 (MMC_RSP_PRESENT|MMC_RSP_CRC|MMC_RSP_OPCODE)
+#define MMC_RSP_R1B (MMC_RSP_PRESENT|MMC_RSP_CRC|MMC_RSP_OPCODE|MMC_RSP_BUSY)