]> git.karo-electronics.de Git - karo-tx-uboot.git/blobdiff - drivers/mtd/nand/sunxi_nand_spl.c
spl: nand: sunxi: add support for NAND config auto-detection
[karo-tx-uboot.git] / drivers / mtd / nand / sunxi_nand_spl.c
index b43f2afc22fea557bbe3ea0f77dedbe4131a7179..1ef7366d4c42d0cd4fdcb77af7acd29bc5251d96 100644 (file)
@@ -103,6 +103,7 @@ struct nfc_config {
        int addr_cycles;
        int nseeds;
        bool randomize;
+       bool valid;
 };
 
 /* minimal "boot0" style NAND support for Allwinner A20 */
@@ -219,6 +220,26 @@ static int nand_load_page(const struct nfc_config *conf, u32 offs)
        return 0;
 }
 
+static int nand_reset_column(void)
+{
+       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(0, SUNXI_NFC_BASE + NFC_ADDR_LOW);
+       writel(NFC_SEND_CMD1 | NFC_SEND_CMD2 | NFC_RAW_CMD |
+              (1 << NFC_ADDR_NUM_OFFSET) | NFC_SEND_ADR | NFC_CMD_RNDOUT,
+              SUNXI_NFC_BASE + NFC_CMD);
+
+       if (!check_value(SUNXI_NFC_BASE + NFC_ST, NFC_ST_CMD_INT_FLAG,
+                        DEFAULT_TIMEOUT_US)) {
+               printf("Error while initializing dma interrupt\n");
+               return -1;
+       }
+
+       return 0;
+}
+
 static int nand_read_page(const struct nfc_config *conf, u32 offs,
                          void *dest, int len)
 {
@@ -303,88 +324,213 @@ static int nand_read_page(const struct nfc_config *conf, u32 offs,
        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)
+static int nand_max_ecc_strength(struct nfc_config *conf)
 {
-       void *end = dest + size;
-       static const u8 strengths[] = { 16, 24, 28, 32, 40, 48, 56, 60, 64 };
-       struct nfc_config conf = {
-               .page_size = page_size,
-               .ecc_size = ecc_page_size,
-               .addr_cycles = addr_cycles,
-               .nseeds = ARRAY_SIZE(random_seed),
-               .randomize = true,
-       };
+       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;
 
-       for (i = 0; i < ARRAY_SIZE(strengths); i++) {
-               if (ecc_strength == strengths[i]) {
-                       conf.ecc_strength = i;
+       /*
+        * 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;
+       }
+
+       max_ecc_bytes = max_oobsize / nsectors;
+
+       for (i = 0; i < ARRAY_SIZE(ecc_bytes); i++) {
+               if (ecc_bytes[i] > max_ecc_bytes)
                        break;
-               }
        }
 
+       if (!i)
+               return -EINVAL;
 
-       nand_apply_config(&conf);
+       return i - 1;
+}
 
-       for ( ;dest < end; dest += ecc_page_size, offs += page_size) {
-               if (nand_load_page(&conf, offs))
-                       return -1;
+static int nand_detect_ecc_config(struct nfc_config *conf, u32 offs,
+                                 void *dest)
+{
+       /* 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_read_page(&conf, offs, dest, page_size))
-                       return -1;
+       /*
+        * 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_reset_column())
+                               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;
+                       }
+
+                       conf->randomize = true;
+                       conf->nseeds = ARRAY_SIZE(random_seed);
+                       do {
+                               if (nand_reset_column())
+                                       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 0;
+       return -EINVAL;
 }
 
-static int nand_read_buffer(uint32_t offs, unsigned int size, void *dest)
+static int nand_detect_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;
+       if (conf->valid)
+               return 0;
 
-       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) == 0) {
-                               debug("success\n");
-                               nand_config = i;
+       /*
+        * Modern NANDs are more likely than legacy ones, so we start testing
+        * with 5 address cycles.
+        */
+       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;
                        }
-                       debug("failed\n");
                }
-               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);
+       return -EINVAL;
+}
+
+static int nand_read_buffer(struct nfc_config *conf, uint32_t offs,
+                           unsigned int size, void *dest)
+{
+       int first_seed, page, ret;
+
+       size = ALIGN(size, conf->page_size);
+       page = offs / conf->page_size;
+       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_reset_column())
+                               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);
+               }
+
+               page++;
+               offs += conf->page_size;
+               dest += conf->page_size;
+       }
+
+       return 0;
 }
 
 int nand_spl_load_image(uint32_t offs, unsigned int size, void *dest)
 {
-       return nand_read_buffer(offs, size, 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)