board/ti/am43xx: add support for parallel NAND

This patch adds support for NAND device connected to GPMC chip-select on
following AM43xx EVM boards.

am437x-gp-evm: On this board, NAND Flash signals are muxed with eMMC, thus at a
  time either eMMC or NAND can be enabled. Selection between eMMC and NAND is
  controlled by:
  (a) Statically using Jumper on connecter (J89) present on board.
  (a) If Jumper on J89 is NOT used, then selection can be dynamically controlled
      by driving SPI2_CS0[MUX_MODE=GPIO] pin via software:
      SPI2_CS0 == 0: NAND (default)
      SPI2_CS0 == 1: eMMC

am43x-epos-evm: On this board, NAND Flash control lines are muxed with QSPI,
  Thus only one of the two can be used at a time. Selection is controlled by:
  (a) Dynamically driving following GPIO pin from software
      GPMC_A0(GPIO) == 0 NAND is selected (default)

NAND device (MT29F4G08AB) on these boards has:
 - data-width=8bits
 - blocksize=256KB
 - pagesize=4KB
 - oobsize=224 bytes
For above NAND device, ROM code expects the boot-loader to be flashed in BCH16
ECC scheme for NAND boot, So by default BCH16 ECC is enabled for AM43xx EVMs.

Signed-off-by: Pekon Gupta <pekon@ti.com>

board/ti/am43xx/board.c

@@ -626,6 +626,7 @@ int board_init(void)
 	    modena_init0_bw_integer, modena_init0_watermark_0;
 
 	gd->bd->bi_boot_params = CONFIG_SYS_SDRAM_BASE + 0x100;
+	gpmc_init();
 
 	/* Clear all important bits for DSS errata that may need to be tweaked*/
 	mreqprio_0 = readl(&cdev->mreqprio_0) & MREQPRIO_0_SAB_INIT1_MASK &

board/ti/am43xx/mux.c

@@ -73,7 +73,38 @@ static struct module_pin_mux gpio5_7_pin_mux[] = {
 	{-1},
 };
 
-static struct module_pin_mux qspi_pin_mux[] = {
+#ifdef CONFIG_NAND
+static struct module_pin_mux nand_pin_mux[] = {
+	{OFFSET(gpmc_ad0),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD0 */
+	{OFFSET(gpmc_ad1),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD1 */
+	{OFFSET(gpmc_ad2),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD2 */
+	{OFFSET(gpmc_ad3),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD3 */
+	{OFFSET(gpmc_ad4),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD4 */
+	{OFFSET(gpmc_ad5),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD5 */
+	{OFFSET(gpmc_ad6),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD6 */
+	{OFFSET(gpmc_ad7),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD7 */
+#ifdef CONFIG_SYS_NAND_BUSWIDTH_16BIT
+	{OFFSET(gpmc_ad8),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD8  */
+	{OFFSET(gpmc_ad9),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD9  */
+	{OFFSET(gpmc_ad10),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD10 */
+	{OFFSET(gpmc_ad11),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD11 */
+	{OFFSET(gpmc_ad12),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD12 */
+	{OFFSET(gpmc_ad13),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD13 */
+	{OFFSET(gpmc_ad14),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD14 */
+	{OFFSET(gpmc_ad15),	(MODE(0) | PULLUDDIS | RXACTIVE)}, /* AD15 */
+#endif
+	{OFFSET(gpmc_wait0),	(MODE(0) | RXACTIVE | PULLUP_EN)}, /* Wait */
+	{OFFSET(gpmc_wpn),	(MODE(7) | PULLUP_EN)},	/* Write Protect */
+	{OFFSET(gpmc_csn0),	(MODE(0) | PULLUP_EN)},	/* Chip-Select */
+	{OFFSET(gpmc_wen),	(MODE(0) | PULLDOWN_EN)}, /* Write Enable */
+	{OFFSET(gpmc_oen_ren),	(MODE(0) | PULLDOWN_EN)}, /* Read Enable */
+	{OFFSET(gpmc_advn_ale),	(MODE(0) | PULLDOWN_EN)}, /* Addr Latch Enable*/
+	{OFFSET(gpmc_be0n_cle),	(MODE(0) | PULLDOWN_EN)}, /* Byte Enable */
+	{-1},
+};
+#endif
+
+static __maybe_unused struct module_pin_mux qspi_pin_mux[] = {
 	{OFFSET(gpmc_csn0), (MODE(3) | PULLUP_EN | RXACTIVE)}, /* QSPI_CS0 */
 	{OFFSET(gpmc_csn3), (MODE(2) | PULLUP_EN | RXACTIVE)}, /* QSPI_CLK */
 	{OFFSET(gpmc_advn_ale), (MODE(3) | PULLUP_EN | RXACTIVE)}, /* QSPI_D0 */
@@ -97,12 +128,22 @@ void enable_board_pin_mux(void)
 	if (board_is_gpevm()) {
 		configure_module_pin_mux(gpio5_7_pin_mux);
 		configure_module_pin_mux(rgmii1_pin_mux);
+#if defined(CONFIG_NAND)
+		configure_module_pin_mux(nand_pin_mux);
+#endif
 	} else if (board_is_sk()) {
 		configure_module_pin_mux(rgmii1_pin_mux);
+#if defined(CONFIG_NAND)
+		printf("Error: NAND flash not present on this board\n");
+#endif
 		configure_module_pin_mux(qspi_pin_mux);
 	} else if (board_is_eposevm()) {
 		configure_module_pin_mux(rmii1_pin_mux);
+#if defined(CONFIG_NAND)
+		configure_module_pin_mux(nand_pin_mux);
+#else
 		configure_module_pin_mux(qspi_pin_mux);
+#endif
 	}
 }
 

include/configs/am43xx_evm.h

@@ -265,4 +265,68 @@
 #define CONFIG_SPL_NET_SUPPORT
 #define CONFIG_SYS_RX_ETH_BUFFER	64
 
+/* NAND support */
+#ifdef CONFIG_NAND
+/* NAND: device related configs */
+#define CONFIG_SYS_NAND_PAGE_SIZE	4096
+#define CONFIG_SYS_NAND_OOBSIZE		224
+#define CONFIG_SYS_NAND_BLOCK_SIZE	(256*1024)
+#define CONFIG_SYS_NAND_PAGE_COUNT	(CONFIG_SYS_NAND_BLOCK_SIZE / \
+					 CONFIG_SYS_NAND_PAGE_SIZE)
+#define CONFIG_SYS_NAND_5_ADDR_CYCLE
+/* NAND: driver related configs */
+#define CONFIG_NAND_OMAP_GPMC
+#define CONFIG_NAND_OMAP_ELM
+#define CONFIG_SYS_NAND_ONFI_DETECTION
+#define CONFIG_NAND_OMAP_ECCSCHEME	OMAP_ECC_BCH16_CODE_HW
+#define CONFIG_SYS_NAND_BAD_BLOCK_POS	NAND_LARGE_BADBLOCK_POS
+#define CONFIG_SYS_NAND_ECCPOS	{ 2, 3, 4, 5, 6, 7, 8, 9, \
+				10, 11, 12, 13, 14, 15, 16, 17, 18, 19, \
+				20, 21, 22, 23, 24, 25, 26, 27, 28, 29, \
+				30, 31, 32, 33, 34, 35, 36, 37, 38, 39, \
+				40, 41, 42, 43, 44, 45, 46, 47, 48, 49, \
+				50, 51, 52, 53, 54, 55, 56, 57, 58, 59, \
+				60, 61, 62, 63, 64, 65, 66, 67, 68, 69, \
+				70, 71, 72, 73, 74, 75, 76, 77, 78, 79, \
+				80, 81, 82, 83, 84, 85, 86, 87, 88, 89, \
+				90, 91, 92, 93, 94, 95, 96, 97, 98, 99, \
+			100, 101, 102, 103, 104, 105, 106, 107, 108, 109, \
+			110, 111, 112, 113, 114, 115, 116, 117, 118, 119, \
+			120, 121, 122, 123, 124, 125, 126, 127, 128, 129, \
+			130, 131, 132, 133, 134, 135, 136, 137, 138, 139, \
+			140, 141, 142, 143, 144, 145, 146, 147, 148, 149, \
+			150, 151, 152, 153, 154, 155, 156, 157, 158, 159, \
+			160, 161, 162, 163, 164, 165, 166, 167, 168, 169, \
+			170, 171, 172, 173, 174, 175, 176, 177, 178, 179, \
+			180, 181, 182, 183, 184, 185, 186, 187, 188, 189, \
+			190, 191, 192, 193, 194, 195, 196, 197, 198, 199, \
+			200, 201, 202, 203, 204, 205, 206, 207, 208, 209, \
+			}
+#define CONFIG_SYS_NAND_ECCSIZE		512
+#define CONFIG_SYS_NAND_ECCBYTES	26
+#define MTDIDS_DEFAULT			"nand0=nand.0"
+#define MTDPARTS_DEFAULT		"mtdparts=nand.0:" \
+					"256k(NAND.SPL)," \
+					"256k(NAND.SPL.backup1)," \
+					"256k(NAND.SPL.backup2)," \
+					"256k(NAND.SPL.backup3)," \
+					"512k(NAND.u-boot-spl-os)," \
+					"1m(NAND.u-boot)," \
+					"256k(NAND.u-boot-env)," \
+					"256k(NAND.u-boot-env.backup1)," \
+					"7m(NAND.kernel)," \
+					"-(NAND.rootfs)"
+#define CONFIG_SYS_NAND_U_BOOT_OFFS	0x00180000
+/* NAND: SPL related configs */
+#ifdef CONFIG_SPL_NAND_SUPPORT
+#define CONFIG_SPL_NAND_AM33XX_BCH
+#endif
+/* NAND: SPL falcon mode configs */
+#ifdef CONFIG_SPL_OS_BOOT
+#define CONFIG_CMD_SPL_NAND_OFS		0x00100000 /* os parameters */
+#define CONFIG_SYS_NAND_SPL_KERNEL_OFFS	0x00300000 /* kernel offset */
+#define CONFIG_CMD_SPL_WRITE_SIZE	CONFIG_SYS_NAND_BLOCK_SIZE
+#endif
+#endif /* !CONFIG_NAND */
+
 #endif	/* __CONFIG_AM43XX_EVM_H */