#define GPMC_ECC_CONTROL 0x1f8
#define GPMC_ECC_SIZE_CONFIG 0x1fc
#define GPMC_ECC1_RESULT 0x200
+#define GPMC_ECC_BCH_RESULT_0 0x240 /* not available on OMAP2 */
/* GPMC ECC control settings */
#define GPMC_ECC_CTRL_ECCCLEAR 0x100
return 0;
}
EXPORT_SYMBOL_GPL(gpmc_calculate_ecc);
+
+#ifdef CONFIG_ARCH_OMAP3
+
+/**
+ * gpmc_init_hwecc_bch - initialize hardware BCH ecc functionality
+ * @cs: chip select number
+ * @nsectors: how many 512-byte sectors to process
+ * @nerrors: how many errors to correct per sector (4 or 8)
+ *
+ * This function must be executed before any call to gpmc_enable_hwecc_bch.
+ */
+int gpmc_init_hwecc_bch(int cs, int nsectors, int nerrors)
+{
+ /* check if ecc module is in use */
+ if (gpmc_ecc_used != -EINVAL)
+ return -EINVAL;
+
+ /* support only OMAP3 class */
+ if (!cpu_is_omap34xx()) {
+ printk(KERN_ERR "BCH ecc is not supported on this CPU\n");
+ return -EINVAL;
+ }
+
+ /*
+ * For now, assume 4-bit mode is only supported on OMAP3630 ES1.x, x>=1.
+ * Other chips may be added if confirmed to work.
+ */
+ if ((nerrors == 4) &&
+ (!cpu_is_omap3630() || (GET_OMAP_REVISION() == 0))) {
+ printk(KERN_ERR "BCH 4-bit mode is not supported on this CPU\n");
+ return -EINVAL;
+ }
+
+ /* sanity check */
+ if (nsectors > 8) {
+ printk(KERN_ERR "BCH cannot process %d sectors (max is 8)\n",
+ nsectors);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gpmc_init_hwecc_bch);
+
+/**
+ * gpmc_enable_hwecc_bch - enable hardware BCH ecc functionality
+ * @cs: chip select number
+ * @mode: read/write mode
+ * @dev_width: device bus width(1 for x16, 0 for x8)
+ * @nsectors: how many 512-byte sectors to process
+ * @nerrors: how many errors to correct per sector (4 or 8)
+ */
+int gpmc_enable_hwecc_bch(int cs, int mode, int dev_width, int nsectors,
+ int nerrors)
+{
+ unsigned int val;
+
+ /* check if ecc module is in use */
+ if (gpmc_ecc_used != -EINVAL)
+ return -EINVAL;
+
+ gpmc_ecc_used = cs;
+
+ /* clear ecc and enable bits */
+ gpmc_write_reg(GPMC_ECC_CONTROL, 0x1);
+
+ /*
+ * When using BCH, sector size is hardcoded to 512 bytes.
+ * Here we are using wrapping mode 6 both for reading and writing, with:
+ * size0 = 0 (no additional protected byte in spare area)
+ * size1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area)
+ */
+ gpmc_write_reg(GPMC_ECC_SIZE_CONFIG, (32 << 22) | (0 << 12));
+
+ /* BCH configuration */
+ val = ((1 << 16) | /* enable BCH */
+ (((nerrors == 8) ? 1 : 0) << 12) | /* 8 or 4 bits */
+ (0x06 << 8) | /* wrap mode = 6 */
+ (dev_width << 7) | /* bus width */
+ (((nsectors-1) & 0x7) << 4) | /* number of sectors */
+ (cs << 1) | /* ECC CS */
+ (0x1)); /* enable ECC */
+
+ gpmc_write_reg(GPMC_ECC_CONFIG, val);
+ gpmc_write_reg(GPMC_ECC_CONTROL, 0x101);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gpmc_enable_hwecc_bch);
+
+/**
+ * gpmc_calculate_ecc_bch4 - Generate 7 ecc bytes per sector of 512 data bytes
+ * @cs: chip select number
+ * @dat: The pointer to data on which ecc is computed
+ * @ecc: The ecc output buffer
+ */
+int gpmc_calculate_ecc_bch4(int cs, const u_char *dat, u_char *ecc)
+{
+ int i;
+ unsigned long nsectors, reg, val1, val2;
+
+ if (gpmc_ecc_used != cs)
+ return -EINVAL;
+
+ nsectors = ((gpmc_read_reg(GPMC_ECC_CONFIG) >> 4) & 0x7) + 1;
+
+ for (i = 0; i < nsectors; i++) {
+
+ reg = GPMC_ECC_BCH_RESULT_0 + 16*i;
+
+ /* Read hw-computed remainder */
+ val1 = gpmc_read_reg(reg + 0);
+ val2 = gpmc_read_reg(reg + 4);
+
+ /*
+ * Add constant polynomial to remainder, in order to get an ecc
+ * sequence of 0xFFs for a buffer filled with 0xFFs; and
+ * left-justify the resulting polynomial.
+ */
+ *ecc++ = 0x28 ^ ((val2 >> 12) & 0xFF);
+ *ecc++ = 0x13 ^ ((val2 >> 4) & 0xFF);
+ *ecc++ = 0xcc ^ (((val2 & 0xF) << 4)|((val1 >> 28) & 0xF));
+ *ecc++ = 0x39 ^ ((val1 >> 20) & 0xFF);
+ *ecc++ = 0x96 ^ ((val1 >> 12) & 0xFF);
+ *ecc++ = 0xac ^ ((val1 >> 4) & 0xFF);
+ *ecc++ = 0x7f ^ ((val1 & 0xF) << 4);
+ }
+
+ gpmc_ecc_used = -EINVAL;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gpmc_calculate_ecc_bch4);
+
+/**
+ * gpmc_calculate_ecc_bch8 - Generate 13 ecc bytes per block of 512 data bytes
+ * @cs: chip select number
+ * @dat: The pointer to data on which ecc is computed
+ * @ecc: The ecc output buffer
+ */
+int gpmc_calculate_ecc_bch8(int cs, const u_char *dat, u_char *ecc)
+{
+ int i;
+ unsigned long nsectors, reg, val1, val2, val3, val4;
+
+ if (gpmc_ecc_used != cs)
+ return -EINVAL;
+
+ nsectors = ((gpmc_read_reg(GPMC_ECC_CONFIG) >> 4) & 0x7) + 1;
+
+ for (i = 0; i < nsectors; i++) {
+
+ reg = GPMC_ECC_BCH_RESULT_0 + 16*i;
+
+ /* Read hw-computed remainder */
+ val1 = gpmc_read_reg(reg + 0);
+ val2 = gpmc_read_reg(reg + 4);
+ val3 = gpmc_read_reg(reg + 8);
+ val4 = gpmc_read_reg(reg + 12);
+
+ /*
+ * Add constant polynomial to remainder, in order to get an ecc
+ * sequence of 0xFFs for a buffer filled with 0xFFs.
+ */
+ *ecc++ = 0xef ^ (val4 & 0xFF);
+ *ecc++ = 0x51 ^ ((val3 >> 24) & 0xFF);
+ *ecc++ = 0x2e ^ ((val3 >> 16) & 0xFF);
+ *ecc++ = 0x09 ^ ((val3 >> 8) & 0xFF);
+ *ecc++ = 0xed ^ (val3 & 0xFF);
+ *ecc++ = 0x93 ^ ((val2 >> 24) & 0xFF);
+ *ecc++ = 0x9a ^ ((val2 >> 16) & 0xFF);
+ *ecc++ = 0xc2 ^ ((val2 >> 8) & 0xFF);
+ *ecc++ = 0x97 ^ (val2 & 0xFF);
+ *ecc++ = 0x79 ^ ((val1 >> 24) & 0xFF);
+ *ecc++ = 0xe5 ^ ((val1 >> 16) & 0xFF);
+ *ecc++ = 0x24 ^ ((val1 >> 8) & 0xFF);
+ *ecc++ = 0xb5 ^ (val1 & 0xFF);
+ }
+
+ gpmc_ecc_used = -EINVAL;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gpmc_calculate_ecc_bch8);
+
+#endif /* CONFIG_ARCH_OMAP3 */
git.openpandora.org / pandora-kernel.git / blobdiff