zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/drivers/mtd/zftl_ecc.c b/ap/os/linux/linux-3.4.x/drivers/mtd/zftl_ecc.c
new file mode 100644
index 0000000..53aee60
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/mtd/zftl_ecc.c
@@ -0,0 +1,119 @@
+#include <linux/mtd/zftl_ecc.h>
+#include <linux/bitops.h>
+
+
+
+static const unsigned char column_parity_table[] = {
+ 0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+ 0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+ 0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+ 0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+ 0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+ 0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+ 0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+ 0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+ 0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+ 0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+ 0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+ 0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+ 0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+ 0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+ 0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+ 0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+ 0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+ 0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+ 0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+ 0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+ 0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+ 0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+ 0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+ 0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+ 0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+ 0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+ 0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+ 0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+ 0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+ 0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+ 0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+ 0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+};
+
+
+void zftl_ecc_calc_other(const unsigned char *data, unsigned n_bytes,
+ struct zftl_ecc_other *ecc_other)
+{
+ unsigned int i;
+
+ unsigned char col_parity = 0;
+ unsigned line_parity = 0;
+ unsigned line_parity_prime = 0;
+ unsigned char b;
+
+ for (i = 0; i < n_bytes; i++) {
+ b = column_parity_table[*data++];
+ col_parity ^= b;
+
+ if (b & 0x01) {
+ /* odd number of bits in the byte */
+ line_parity ^= i;
+ line_parity_prime ^= ~i;
+ }
+
+ }
+
+ ecc_other->col_parity = (col_parity >> 2) & 0x3f;
+ ecc_other->line_parity = line_parity;
+ ecc_other->line_parity_prime = line_parity_prime;
+}
+
+int zftl_ecc_correct_other(unsigned char *data, unsigned n_bytes,
+ struct zftl_ecc_other *read_ecc,
+ const struct zftl_ecc_other *test_ecc)
+{
+ unsigned char delta_col; /* column parity delta */
+ unsigned delta_line; /* line parity delta */
+ unsigned delta_line_prime; /* line parity delta */
+ unsigned bit;
+
+ delta_col = read_ecc->col_parity ^ test_ecc->col_parity;
+ delta_line = read_ecc->line_parity ^ test_ecc->line_parity;
+ delta_line_prime =
+ read_ecc->line_parity_prime ^ test_ecc->line_parity_prime;
+
+ if ((delta_col | delta_line | delta_line_prime) == 0)
+ return 0; /* no error */
+
+ if (delta_line == ~delta_line_prime &&
+ (((delta_col ^ (delta_col >> 1)) & 0x15) == 0x15)) {
+ /* Single bit (recoverable) error in data */
+
+ bit = 0;
+
+ if (delta_col & 0x20)
+ bit |= 0x04;
+ if (delta_col & 0x08)
+ bit |= 0x02;
+ if (delta_col & 0x02)
+ bit |= 0x01;
+
+ if (delta_line >= n_bytes)
+ return -1;
+
+ data[delta_line] ^= (1 << bit);
+
+ return 1; /* corrected */
+ }
+
+ if ((hweight32(delta_line) +
+ hweight32(delta_line_prime) +
+ hweight8(delta_col)) == 1) {
+ /* Reccoverable error in ecc */
+
+ *read_ecc = *test_ecc;
+ return 1; /* corrected */
+ }
+
+ /* Unrecoverable error */
+
+ return -1;
+}