sunxi_nand_spl: Auto detect nand configuration parameters

Auto detect the nand configuration parameters, like the BROM does.

This allows us to get rid of various Kconfig settings, and is
necessary to support generic boards like the mk802 which have seen
many production runs with different nands.

The full blown u-boot/kernel nand driver uses the nand id to determine
this info, for the SPL we do as the BROM does and simply try a few
standard configs.

Note the table only contains configs which are known to actually be used,
rather then all the configs the BROM tries. This means that it may need
to be updated in the future as we add support for nand on more boards.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

drivers/mtd/nand/Kconfig

@@ -99,8 +99,6 @@ config SPL_NAND_SUNXI
 	---help---
 	Enable support for NAND. This option allows SPL to read from
 	sunxi NAND using DMA transfers.
-	Depending on the NAND chip, values like ECC strength and page sizes
-	have to be configured.
 
 config NAND_SUNXI_SPL_SYNDROME_PARTITIONS_END
 	hex "Size of syndrome partitions in sunxi NAND"
@@ -110,29 +108,6 @@ config NAND_SUNXI_SPL_SYNDROME_PARTITIONS_END
 	End address for boot partitions on NAND. Those partitions have a
 	different random seed that has to match the sunxi BROM setting.
 
-config NAND_SUNXI_SPL_ECC_STRENGTH
-	int "ECC Strength for sunxi NAND"
-	default 40
-	depends on SPL_NAND_SUNXI
-	---help---
-	ECC strength used by the sunxi NAND SPL driver. This is specific to the
-	chosen NAND chip and has to match the value used by the sunxi BROM.
-
-config NAND_SUNXI_SPL_ECC_PAGE_SIZE
-	hex "ECC page size for sunxi NAND"
-	default 0x400
-	depends on SPL_NAND_SUNXI
-	---help---
-	ECC page size used by the sunxi NAND SPL driver for syndrome partitions.
-	This setting has to match the value used by the sunxi BROM.
-
-config NAND_SUNXI_SPL_PAGE_SIZE
-	hex "Page size for sunxi NAND"
-	default 0x2000
-	depends on SPL_NAND_SUNXI
-	---help---
-	Page size of the NAND flash used by the sunxi NAND SPL driver. This is
-	specific to the chosen NAND chip.
 endif
 
 endmenu

drivers/mtd/nand/sunxi_nand_spl.c

@@ -307,10 +307,45 @@ static int nand_read_ecc(int page_size, int ecc_strength, int ecc_page_size,
 static int nand_read_buffer(uint32_t offs, unsigned int size, void *dest,
 			    int syndrome)
 {
-	return nand_read_ecc(CONFIG_NAND_SUNXI_SPL_PAGE_SIZE,
-			     CONFIG_NAND_SUNXI_SPL_ECC_STRENGTH,
-			     CONFIG_NAND_SUNXI_SPL_ECC_PAGE_SIZE,
-			     5, offs, size, dest, syndrome);
+	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 },
+	};
+	static int nand_config = -1;
+	int i;
+
+	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;
+				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, syndrome);
 }
 
 int nand_spl_load_image(uint32_t offs, unsigned int size, void *dest)