spl: nand: sunxi: make the reset column helper more generic
[oweals/u-boot.git] / drivers / mtd / nand / sunxi_nand_spl.c
index b0e07aa2d088a27977ddbb380d263b4a10e4a2be..9ebdcee3513e2753449d502720b8f609febd24a4 100644 (file)
@@ -55,7 +55,7 @@
 
 
 #define NFC_ADDR_NUM_OFFSET        16
-#define NFC_SEND_AD              (1 << 19)
+#define NFC_SEND_ADDR              (1 << 19)
 #define NFC_ACCESS_DIR             (1 << 20)
 #define NFC_DATA_TRANS             (1 << 21)
 #define NFC_SEND_CMD1              (1 << 22)
@@ -66,6 +66,8 @@
 #define NFC_ROW_AUTO_INC           (1 << 27)
 #define NFC_SEND_CMD3              (1 << 28)
 #define NFC_SEND_CMD4              (1 << 29)
+#define NFC_RAW_CMD                (0 << 30)
+#define NFC_PAGE_CMD               (2 << 30)
 
 #define NFC_ST_CMD_INT_FLAG        (1 << 1)
 #define NFC_ST_DMA_INT_FLAG        (1 << 2)
@@ -78,9 +80,6 @@
 #define NFC_CMD_RNDOUT             0x05
 #define NFC_CMD_READSTART          0x30
 
-
-#define NFC_PAGE_CMD               (2 << 30)
-
 #define SUNXI_DMA_CFG_REG0              0x300
 #define SUNXI_DMA_SRC_START_ADDR_REG0   0x304
 #define SUNXI_DMA_DEST_START_ADDRR_REG0 0x308
 #define SUNXI_DMA_DDMA_PARA_REG_SRC_WAIT_CYC (0x0F << 0)
 #define SUNXI_DMA_DDMA_PARA_REG_SRC_BLK_SIZE (0x7F << 8)
 
+struct nfc_config {
+       int page_size;
+       int ecc_strength;
+       int ecc_size;
+       int addr_cycles;
+       int nseeds;
+       bool randomize;
+       bool valid;
+};
+
 /* minimal "boot0" style NAND support for Allwinner A20 */
 
 /* random seed used by linux */
@@ -119,38 +128,67 @@ const uint16_t random_seed[128] = {
        0x7c57, 0x0fbe, 0x46ce, 0x4939, 0x6b17, 0x37bb, 0x3e91, 0x76db,
 };
 
-/* random seed used for syndrome calls */
-const uint16_t random_seed_syndrome = 0x4a80;
-
-#define MAX_RETRIES 10
+#define DEFAULT_TIMEOUT_US     100000
 
 static int check_value_inner(int offset, int expected_bits,
-                               int max_number_of_retries, int negation)
+                            int timeout_us, int negation)
 {
-       int retries = 0;
        do {
                int val = readl(offset) & expected_bits;
                if (negation ? !val : val)
                        return 1;
-               mdelay(1);
-               retries++;
-       } while (retries < max_number_of_retries);
+               udelay(1);
+       } while (--timeout_us);
 
        return 0;
 }
 
 static inline int check_value(int offset, int expected_bits,
-                               int max_number_of_retries)
+                             int timeout_us)
 {
-       return check_value_inner(offset, expected_bits,
-                                       max_number_of_retries, 0);
+       return check_value_inner(offset, expected_bits, timeout_us, 0);
 }
 
 static inline int check_value_negated(int offset, int unexpected_bits,
-                                       int max_number_of_retries)
+                                     int timeout_us)
+{
+       return check_value_inner(offset, unexpected_bits, timeout_us, 1);
+}
+
+static int nand_wait_cmd_fifo_empty(void)
+{
+       if (!check_value_negated(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_FIFO_STAT,
+                                DEFAULT_TIMEOUT_US)) {
+               printf("nand: timeout waiting for empty cmd FIFO\n");
+               return -ETIMEDOUT;
+       }
+
+       return 0;
+}
+
+static int nand_wait_int(void)
 {
-       return check_value_inner(offset, unexpected_bits,
-                                       max_number_of_retries, 1);
+       if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_INT_FLAG,
+                        DEFAULT_TIMEOUT_US)) {
+               printf("nand: timeout waiting for interruption\n");
+               return -ETIMEDOUT;
+       }
+
+       return 0;
+}
+
+static int nand_exec_cmd(u32 cmd)
+{
+       int ret;
+
+       ret = nand_wait_cmd_fifo_empty();
+       if (ret)
+               return ret;
+
+       writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
+       writel(cmd, SUNXI_NFC_BASE + NFC_CMD);
+
+       return nand_wait_int();
 }
 
 void nand_init(void)
@@ -165,74 +203,95 @@ void nand_init(void)
               SUNXI_NFC_BASE + NFC_CTL);
 
        if (!check_value_negated(SUNXI_NFC_BASE + NFC_CTL,
-                                NFC_CTL_RESET, MAX_RETRIES)) {
+                                NFC_CTL_RESET, DEFAULT_TIMEOUT_US)) {
                printf("Couldn't initialize nand\n");
        }
 
        /* reset NAND */
-       writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
-       writel(NFC_SEND_CMD1 | NFC_WAIT_FLAG | NAND_CMD_RESET,
-              SUNXI_NFC_BASE + NFC_CMD);
+       nand_exec_cmd(NFC_SEND_CMD1 | NFC_WAIT_FLAG | NAND_CMD_RESET);
+}
 
-       if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_INT_FLAG,
-                        MAX_RETRIES)) {
-               printf("Error timeout waiting for nand reset\n");
-               return;
-       }
-       writel(NFC_ST_CMD_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
+static void nand_apply_config(const struct nfc_config *conf)
+{
+       u32 val;
+
+       nand_wait_cmd_fifo_empty();
+
+       val = readl(SUNXI_NFC_BASE + NFC_CTL);
+       val &= ~NFC_CTL_PAGE_SIZE_MASK;
+       writel(val | NFC_CTL_RAM_METHOD | NFC_CTL_PAGE_SIZE(conf->page_size),
+              SUNXI_NFC_BASE + NFC_CTL);
+       writel(conf->ecc_size, SUNXI_NFC_BASE + NFC_CNT);
+       writel(conf->page_size, SUNXI_NFC_BASE + NFC_SPARE_AREA);
 }
 
-static int nand_read_page(int page_size, int ecc_strength, int ecc_page_size,
-       int addr_cycles, uint32_t real_addr, dma_addr_t dst, int syndrome)
+static int nand_load_page(const struct nfc_config *conf, u32 offs)
 {
-       uint32_t val;
-       int i, ecc_off = 0;
-       uint16_t ecc_mode = 0;
-       uint16_t rand_seed;
-       uint32_t page;
-       uint16_t column;
-       static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
-
-       for (i = 0; i < ARRAY_SIZE(strengths); i++) {
-               if (ecc_strength == strengths[i]) {
-                       ecc_mode = i;
-                       break;
-               }
-       }
+       int page = offs / conf->page_size;
+
+       writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET) |
+              (NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET) |
+              (NFC_CMD_READSTART << NFC_READ_CMD_OFFSET),
+              SUNXI_NFC_BASE + NFC_RCMD_SET);
+       writel(((page & 0xFFFF) << 16), SUNXI_NFC_BASE + NFC_ADDR_LOW);
+       writel((page >> 16) & 0xFF, SUNXI_NFC_BASE + NFC_ADDR_HIGH);
+
+       return nand_exec_cmd(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
+                            NFC_SEND_ADDR | NFC_WAIT_FLAG |
+                            ((conf->addr_cycles - 1) << NFC_ADDR_NUM_OFFSET));
+}
+
+static int nand_change_column(u16 column)
+{
+       int ret;
+
+       writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET) |
+              (NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET) |
+              (NFC_CMD_RNDOUTSTART << NFC_READ_CMD_OFFSET),
+              SUNXI_NFC_BASE + NFC_RCMD_SET);
+       writel(column, SUNXI_NFC_BASE + NFC_ADDR_LOW);
+
+       ret = nand_exec_cmd(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
+                           (1 << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADDR |
+                           NFC_CMD_RNDOUT);
+       if (ret)
+               return ret;
+
+       /* Ensure tCCS has passed before reading data */
+       udelay(1);
+
+       return 0;
+}
 
-       /* HW ECC always request ECC bytes for 1024 bytes blocks */
-       ecc_off = DIV_ROUND_UP(ecc_strength * fls(8 * 1024), 8);
-       /* HW ECC always work with even numbers of ECC bytes */
-       ecc_off += (ecc_off & 1);
-       ecc_off += 4; /* prepad */
+static int nand_read_page(const struct nfc_config *conf, u32 offs,
+                         void *dest, int len)
+{
+       dma_addr_t dst = (dma_addr_t)dest;
+       int nsectors = len / conf->ecc_size;
+       u16 rand_seed = 0;
+       u32 val;
+       int page;
 
-       page = real_addr / page_size;
-       column = real_addr % page_size;
+       page = offs / conf->page_size;
 
-       if (syndrome)
-               column += (column / ecc_page_size) * ecc_off;
+       if (offs % conf->page_size || len % conf->ecc_size ||
+           len > conf->page_size || len < 0)
+               return -EINVAL;
 
        /* clear ecc status */
        writel(0, SUNXI_NFC_BASE + NFC_ECC_ST);
 
-       /* Choose correct seed */
-       if (syndrome)
-               rand_seed = random_seed_syndrome;
-       else
-               rand_seed = random_seed[page % 128];
+       /* Choose correct seed if randomized */
+       if (conf->randomize)
+               rand_seed = random_seed[page % conf->nseeds];
 
-       writel((rand_seed << 16) | NFC_ECC_RANDOM_EN | NFC_ECC_EN
-               | NFC_ECC_PIPELINE | (ecc_mode << 12),
+       writel((rand_seed << 16) | (conf->ecc_strength << 12) |
+               (conf->randomize ? NFC_ECC_RANDOM_EN : 0) |
+               (conf->ecc_size == 512 ? NFC_ECC_BLOCK_SIZE : 0) |
+               NFC_ECC_EN | NFC_ECC_PIPELINE | NFC_ECC_EXCEPTION,
                SUNXI_NFC_BASE + NFC_ECC_CTL);
 
-       val = readl(SUNXI_NFC_BASE + NFC_CTL);
-       writel(val | NFC_CTL_RAM_METHOD, SUNXI_NFC_BASE + NFC_CTL);
-
-       if (!syndrome)
-               writel(page_size + (column / ecc_page_size) * ecc_off,
-                      SUNXI_NFC_BASE + NFC_SPARE_AREA);
-
-       flush_dcache_range(dst, ALIGN(dst + ecc_page_size, ARCH_DMA_MINALIGN));
+       flush_dcache_range(dst, ALIGN(dst + conf->ecc_size, ARCH_DMA_MINALIGN));
 
        /* SUNXI_DMA */
        writel(0x0, SUNXI_DMA_BASE + SUNXI_DMA_CFG_REG0); /* clr dma cmd */
@@ -241,158 +300,262 @@ static int nand_read_page(int page_size, int ecc_strength, int ecc_page_size,
               SUNXI_DMA_BASE + SUNXI_DMA_SRC_START_ADDR_REG0);
        /* read to RAM */
        writel(dst, SUNXI_DMA_BASE + SUNXI_DMA_DEST_START_ADDRR_REG0);
-       writel(SUNXI_DMA_DDMA_PARA_REG_SRC_WAIT_CYC
-                       | SUNXI_DMA_DDMA_PARA_REG_SRC_BLK_SIZE,
-                       SUNXI_DMA_BASE + SUNXI_DMA_DDMA_PARA_REG0);
-       writel(ecc_page_size,
-              SUNXI_DMA_BASE + SUNXI_DMA_DDMA_BC_REG0); /* 1kB */
-       writel(SUNXI_DMA_DDMA_CFG_REG_LOADING
-               | SUNXI_DMA_DDMA_CFG_REG_DMA_DEST_DATA_WIDTH_32
-               | SUNXI_DMA_DDMA_CFG_REG_DDMA_DST_DRQ_TYPE_DRAM
-               | SUNXI_DMA_DDMA_CFG_REG_DMA_SRC_DATA_WIDTH_32
-               | SUNXI_DMA_DDMA_CFG_REG_DMA_SRC_ADDR_MODE_IO
-               | SUNXI_DMA_DDMA_CFG_REG_DDMA_SRC_DRQ_TYPE_NFC,
-               SUNXI_DMA_BASE + SUNXI_DMA_CFG_REG0);
-
-       writel((NFC_CMD_RNDOUTSTART << NFC_RANDOM_READ_CMD1_OFFSET)
-               | (NFC_CMD_RNDOUT << NFC_RANDOM_READ_CMD0_OFFSET)
-               | (NFC_CMD_READSTART | NFC_READ_CMD_OFFSET), SUNXI_NFC_BASE
-                       + NFC_RCMD_SET);
-       writel(1, SUNXI_NFC_BASE + NFC_SECTOR_NUM);
-       writel(((page & 0xFFFF) << 16) | column,
-              SUNXI_NFC_BASE + NFC_ADDR_LOW);
-       writel((page >> 16) & 0xFF, SUNXI_NFC_BASE + NFC_ADDR_HIGH);
+       writel(SUNXI_DMA_DDMA_PARA_REG_SRC_WAIT_CYC |
+              SUNXI_DMA_DDMA_PARA_REG_SRC_BLK_SIZE,
+              SUNXI_DMA_BASE + SUNXI_DMA_DDMA_PARA_REG0);
+       writel(len, SUNXI_DMA_BASE + SUNXI_DMA_DDMA_BC_REG0);
+       writel(SUNXI_DMA_DDMA_CFG_REG_LOADING |
+              SUNXI_DMA_DDMA_CFG_REG_DMA_DEST_DATA_WIDTH_32 |
+              SUNXI_DMA_DDMA_CFG_REG_DDMA_DST_DRQ_TYPE_DRAM |
+              SUNXI_DMA_DDMA_CFG_REG_DMA_SRC_DATA_WIDTH_32 |
+              SUNXI_DMA_DDMA_CFG_REG_DMA_SRC_ADDR_MODE_IO |
+              SUNXI_DMA_DDMA_CFG_REG_DDMA_SRC_DRQ_TYPE_NFC,
+              SUNXI_DMA_BASE + SUNXI_DMA_CFG_REG0);
+
+       writel(nsectors, SUNXI_NFC_BASE + NFC_SECTOR_NUM);
        writel(NFC_ST_DMA_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
-       writel(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_DATA_TRANS |
-               NFC_PAGE_CMD | NFC_WAIT_FLAG |
-               ((addr_cycles - 1) << NFC_ADDR_NUM_OFFSET) |
-               NFC_SEND_ADR | NFC_DATA_SWAP_METHOD | (syndrome ? NFC_SEQ : 0),
-               SUNXI_NFC_BASE + NFC_CMD);
+       writel(NFC_DATA_TRANS | NFC_PAGE_CMD | NFC_DATA_SWAP_METHOD,
+              SUNXI_NFC_BASE + NFC_CMD);
 
        if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_DMA_INT_FLAG,
-                        MAX_RETRIES)) {
+                        DEFAULT_TIMEOUT_US)) {
                printf("Error while initializing dma interrupt\n");
-               return -1;
+               return -EIO;
        }
        writel(NFC_ST_DMA_INT_FLAG, SUNXI_NFC_BASE + NFC_ST);
 
        if (!check_value_negated(SUNXI_DMA_BASE + SUNXI_DMA_CFG_REG0,
-                                SUNXI_DMA_DDMA_CFG_REG_LOADING, MAX_RETRIES)) {
+                                SUNXI_DMA_DDMA_CFG_REG_LOADING,
+                                DEFAULT_TIMEOUT_US)) {
                printf("Error while waiting for dma transfer to finish\n");
-               return -1;
+               return -EIO;
        }
 
        invalidate_dcache_range(dst,
-                               ALIGN(dst + ecc_page_size, ARCH_DMA_MINALIGN));
+                               ALIGN(dst + conf->ecc_size, ARCH_DMA_MINALIGN));
 
-       if (readl(SUNXI_NFC_BASE + NFC_ECC_ST))
-               return -1;
+       val = readl(SUNXI_NFC_BASE + NFC_ECC_ST);
 
-       return 0;
+       /* ECC error detected. */
+       if (val & 0xffff)
+               return -EIO;
+
+       /*
+        * Return 1 if the page is empty.
+        * We consider the page as empty if the first ECC block is marked
+        * empty.
+        */
+       return (val & 0x10000) ? 1 : 0;
 }
 
-static int nand_read_ecc(int page_size, int ecc_strength, int ecc_page_size,
-       int addr_cycles, uint32_t offs, uint32_t size, void *dest, int syndrome)
+static int nand_max_ecc_strength(struct nfc_config *conf)
 {
-       void *end = dest + size;
+       static const int ecc_bytes[] = { 32, 46, 54, 60, 74, 88, 102, 110, 116 };
+       int max_oobsize, max_ecc_bytes;
+       int nsectors = conf->page_size / conf->ecc_size;
+       int i;
 
-       clrsetbits_le32(SUNXI_NFC_BASE + NFC_CTL, NFC_CTL_PAGE_SIZE_MASK,
-                       NFC_CTL_PAGE_SIZE(page_size));
+       /*
+        * ECC strength is limited by the size of the OOB area which is
+        * correlated with the page size.
+        */
+       switch (conf->page_size) {
+       case 2048:
+               max_oobsize = 64;
+               break;
+       case 4096:
+               max_oobsize = 256;
+               break;
+       case 8192:
+               max_oobsize = 640;
+               break;
+       case 16384:
+               max_oobsize = 1664;
+               break;
+       default:
+               return -EINVAL;
+       }
 
-       for ( ;dest < end; dest += ecc_page_size, offs += ecc_page_size) {
-               if (nand_read_page(page_size, ecc_strength, ecc_page_size,
-                                  addr_cycles, offs, (dma_addr_t)dest,
-                                  syndrome))
-                       return -1;
+       max_ecc_bytes = max_oobsize / nsectors;
+
+       for (i = 0; i < ARRAY_SIZE(ecc_bytes); i++) {
+               if (ecc_bytes[i] > max_ecc_bytes)
+                       break;
        }
 
-       return 0;
+       if (!i)
+               return -EINVAL;
+
+       return i - 1;
 }
 
-static int nand_read_buffer(uint32_t offs, unsigned int size, void *dest,
-                           int syndrome)
+static int nand_detect_ecc_config(struct nfc_config *conf, u32 offs,
+                                 void *dest)
 {
-       const struct {
-               int page_size;
-               int ecc_strength;
-               int ecc_page_size;
-               int addr_cycles;
-       } nand_configs[] = {
-               {  8192, 40, 1024, 5 },
-               { 16384, 56, 1024, 5 },
-               {  8192, 24, 1024, 5 },
-               {  4096, 24, 1024, 5 },
-       };
-       static int nand_config = -1;
-       int i;
+       /* NAND with pages > 4k will likely require 1k sector size. */
+       int min_ecc_size = conf->page_size > 4096 ? 1024 : 512;
+       int page = offs / conf->page_size;
+       int ret;
 
-       if (nand_config == -1) {
-               for (i = 0; i < ARRAY_SIZE(nand_configs); i++) {
-                       debug("nand: trying page %d ecc %d / %d addr %d: ",
-                             nand_configs[i].page_size,
-                             nand_configs[i].ecc_strength,
-                             nand_configs[i].ecc_page_size,
-                             nand_configs[i].addr_cycles);
-                       if (nand_read_ecc(nand_configs[i].page_size,
-                                         nand_configs[i].ecc_strength,
-                                         nand_configs[i].ecc_page_size,
-                                         nand_configs[i].addr_cycles,
-                                         offs, size, dest, syndrome) == 0) {
-                               debug("success\n");
-                               nand_config = i;
+       /*
+        * In most cases, 1k sectors are preferred over 512b ones, start
+        * testing this config first.
+        */
+       for (conf->ecc_size = 1024; conf->ecc_size >= min_ecc_size;
+            conf->ecc_size >>= 1) {
+               int max_ecc_strength = nand_max_ecc_strength(conf);
+
+               nand_apply_config(conf);
+
+               /*
+                * We are starting from the maximum ECC strength because
+                * most of the time NAND vendors provide an OOB area that
+                * barely meets the ECC requirements.
+                */
+               for (conf->ecc_strength = max_ecc_strength;
+                    conf->ecc_strength >= 0;
+                    conf->ecc_strength--) {
+                       conf->randomize = false;
+                       if (nand_change_column(0))
+                               return -EIO;
+
+                       /*
+                        * Only read the first sector to speedup detection.
+                        */
+                       ret = nand_read_page(conf, offs, dest, conf->ecc_size);
+                       if (!ret) {
                                return 0;
+                       } else if (ret > 0) {
+                               /*
+                                * If page is empty we can't deduce anything
+                                * about the ECC config => stop the detection.
+                                */
+                               return -EINVAL;
                        }
-                       debug("failed\n");
+
+                       conf->randomize = true;
+                       conf->nseeds = ARRAY_SIZE(random_seed);
+                       do {
+                               if (nand_change_column(0))
+                                       return -EIO;
+
+                               if (!nand_read_page(conf, offs, dest,
+                                                   conf->ecc_size))
+                                       return 0;
+
+                               /*
+                                * Find the next ->nseeds value that would
+                                * change the randomizer seed for the page
+                                * we're trying to read.
+                                */
+                               while (conf->nseeds >= 16) {
+                                       int seed = page % conf->nseeds;
+
+                                       conf->nseeds >>= 1;
+                                       if (seed != page % conf->nseeds)
+                                               break;
+                               }
+                       } while (conf->nseeds >= 16);
                }
-               return -1;
        }
 
-       return nand_read_ecc(nand_configs[nand_config].page_size,
-                            nand_configs[nand_config].ecc_strength,
-                            nand_configs[nand_config].ecc_page_size,
-                            nand_configs[nand_config].addr_cycles,
-                            offs, size, dest, syndrome);
+       return -EINVAL;
 }
 
-int nand_spl_load_image(uint32_t offs, unsigned int size, void *dest)
+static int nand_detect_config(struct nfc_config *conf, u32 offs, void *dest)
 {
-#if CONFIG_SYS_NAND_U_BOOT_OFFS == CONFIG_SPL_PAD_TO
-       /*
-        * u-boot-dtb.bin appended to SPL, use syndrome (like the BROM does)
-        * and try different erase block sizes to find the backup.
-        */
-       const uint32_t boot_offsets[] = {
-               0 * 1024 * 1024 + CONFIG_SYS_NAND_U_BOOT_OFFS,
-               1 * 1024 * 1024 + CONFIG_SYS_NAND_U_BOOT_OFFS,
-               2 * 1024 * 1024 + CONFIG_SYS_NAND_U_BOOT_OFFS,
-               4 * 1024 * 1024 + CONFIG_SYS_NAND_U_BOOT_OFFS,
-       };
-       const int syndrome = 1;
-#else
+       if (conf->valid)
+               return 0;
+
        /*
-        * u-boot-dtb.bin on its own partition, do not use syndrome, u-boot
-        * partition sits after 2 eraseblocks (spl, spl-backup), look for
-        * backup u-boot 1 erase block further.
+        * Modern NANDs are more likely than legacy ones, so we start testing
+        * with 5 address cycles.
         */
-       const uint32_t eraseblock_size = CONFIG_SYS_NAND_U_BOOT_OFFS / 2;
-       const uint32_t boot_offsets[] = {
-               CONFIG_SYS_NAND_U_BOOT_OFFS,
-               CONFIG_SYS_NAND_U_BOOT_OFFS + eraseblock_size,
-       };
-       const int syndrome = 0;
-#endif
-       int i;
-
-       if (offs == CONFIG_SYS_NAND_U_BOOT_OFFS) {
-               for (i = 0; i < ARRAY_SIZE(boot_offsets); i++) {
-                       if (nand_read_buffer(boot_offsets[i], size,
-                                            dest, syndrome) == 0)
+       for (conf->addr_cycles = 5;
+            conf->addr_cycles >= 4;
+            conf->addr_cycles--) {
+               int max_page_size = conf->addr_cycles == 4 ? 2048 : 16384;
+
+               /*
+                * Ignoring 1k pages cause I'm not even sure this case exist
+                * in the real world.
+                */
+               for (conf->page_size = 2048; conf->page_size <= max_page_size;
+                    conf->page_size <<= 1) {
+                       if (nand_load_page(conf, offs))
+                               return -1;
+
+                       if (!nand_detect_ecc_config(conf, offs, dest)) {
+                               conf->valid = true;
                                return 0;
+                       }
+               }
+       }
+
+       return -EINVAL;
+}
+
+static int nand_read_buffer(struct nfc_config *conf, uint32_t offs,
+                           unsigned int size, void *dest)
+{
+       int first_seed = 0, page, ret;
+
+       size = ALIGN(size, conf->page_size);
+       page = offs / conf->page_size;
+       if (conf->randomize)
+               first_seed = page % conf->nseeds;
+
+       for (; size; size -= conf->page_size) {
+               if (nand_load_page(conf, offs))
+                       return -1;
+
+               ret = nand_read_page(conf, offs, dest, conf->page_size);
+               /*
+                * The ->nseeds value should be equal to the number of pages
+                * in an eraseblock. Since we don't know this information in
+                * advance we might have picked a wrong value.
+                */
+               if (ret < 0 && conf->randomize) {
+                       int cur_seed = page % conf->nseeds;
+
+                       /*
+                        * We already tried all the seed values => we are
+                        * facing a real corruption.
+                        */
+                       if (cur_seed < first_seed)
+                               return -EIO;
+
+                       /* Try to adjust ->nseeds and read the page again... */
+                       conf->nseeds = cur_seed;
+
+                       if (nand_change_column(0))
+                               return -EIO;
+
+                       /* ... it still fails => it's a real corruption. */
+                       if (nand_read_page(conf, offs, dest, conf->page_size))
+                               return -EIO;
+               } else if (ret && conf->randomize) {
+                       memset(dest, 0xff, conf->page_size);
                }
-               return -1;
+
+               page++;
+               offs += conf->page_size;
+               dest += conf->page_size;
        }
 
-       return nand_read_buffer(offs, size, dest, syndrome);
+       return 0;
+}
+
+int nand_spl_load_image(uint32_t offs, unsigned int size, void *dest)
+{
+       static struct nfc_config conf = { };
+       int ret;
+
+       ret = nand_detect_config(&conf, offs, dest);
+       if (ret)
+               return ret;
+
+       return nand_read_buffer(&conf, offs, size, dest);
 }
 
 void nand_deselect(void)