stm32: Add SDRAM support for stm32f746 discovery board

This patch adds SDRAM support for stm32f746 discovery board.
This patch depends on previous patch.
This patch is based on STM32F4 and emcraft's[1].

[1]:  https://github.com/EmcraftSystems/u-boot

Signed-off-by: Toshifumi NISHINAGA <tnishinaga.dev@gmail.com>

1 files changed, 75 insertions, 0 deletions

diff --git a/arch/arm/include/asm/arch-stm32f7/fmc.h b/arch/arm/include/asm/arch-stm32f7/fmc.h
new file mode 100644
index 0000000000..7dd5077d0c
--- /dev/null
+++ b/arch/arm/include/asm/arch-stm32f7/fmc.h
@@ -0,0 +1,75 @@
+/*
+ * (C) Copyright 2013
+ * Pavel Boldin, Emcraft Systems, paboldin@emcraft.com
+ *
+ * (C) Copyright 2015
+ * Kamil Lulko, <kamil.lulko@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _MACH_FMC_H_
+#define _MACH_FMC_H_
+
+struct stm32_fmc_regs {
+	u32 sdcr1;	/* Control register 1 */
+	u32 sdcr2;	/* Control register 2 */
+	u32 sdtr1;	/* Timing register 1 */
+	u32 sdtr2;	/* Timing register 2 */
+	u32 sdcmr;	/* Mode register */
+	u32 sdrtr;	/* Refresh timing register */
+	u32 sdsr;	/* Status register */
+};
+
+/*
+ * FMC registers base
+ */
+#define STM32_SDRAM_FMC_BASE	0xA0000140
+#define STM32_SDRAM_FMC		((struct stm32_fmc_regs *)STM32_SDRAM_FMC_BASE)
+
+/* Control register SDCR */
+#define FMC_SDCR_RPIPE_SHIFT	13	/* RPIPE bit shift */
+#define FMC_SDCR_RBURST_SHIFT	12	/* RBURST bit shift */
+#define FMC_SDCR_SDCLK_SHIFT	10	/* SDRAM clock divisor shift */
+#define FMC_SDCR_WP_SHIFT	9	/* Write protection shift */
+#define FMC_SDCR_CAS_SHIFT	7	/* CAS latency shift */
+#define FMC_SDCR_NB_SHIFT	6	/* Number of banks shift */
+#define FMC_SDCR_MWID_SHIFT	4	/* Memory width shift */
+#define FMC_SDCR_NR_SHIFT	2	/* Number of row address bits shift */
+#define FMC_SDCR_NC_SHIFT	0	/* Number of col address bits shift */
+
+/* Timings register SDTR */
+#define FMC_SDTR_TMRD_SHIFT	0	/* Load mode register to active */
+#define FMC_SDTR_TXSR_SHIFT	4	/* Exit self-refresh time */
+#define FMC_SDTR_TRAS_SHIFT	8	/* Self-refresh time */
+#define FMC_SDTR_TRC_SHIFT	12	/* Row cycle delay */
+#define FMC_SDTR_TWR_SHIFT	16	/* Recovery delay */
+#define FMC_SDTR_TRP_SHIFT	20	/* Row precharge delay */
+#define FMC_SDTR_TRCD_SHIFT	24	/* Row-to-column delay */
+
+
+#define FMC_SDCMR_NRFS_SHIFT	5
+
+#define FMC_SDCMR_MODE_NORMAL		0
+#define FMC_SDCMR_MODE_START_CLOCK	1
+#define FMC_SDCMR_MODE_PRECHARGE	2
+#define FMC_SDCMR_MODE_AUTOREFRESH	3
+#define FMC_SDCMR_MODE_WRITE_MODE	4
+#define FMC_SDCMR_MODE_SELFREFRESH	5
+#define FMC_SDCMR_MODE_POWERDOWN	6
+
+#define FMC_SDCMR_BANK_1		(1 << 4)
+#define FMC_SDCMR_BANK_2		(1 << 3)
+
+#define FMC_SDCMR_MODE_REGISTER_SHIFT	9
+
+#define FMC_SDSR_BUSY			(1 << 5)
+
+#define FMC_BUSY_WAIT()		do { \
+		__asm__ __volatile__ ("dsb" : : : "memory"); \
+		while (STM32_SDRAM_FMC->sdsr & FMC_SDSR_BUSY) \
+			; \
+	} while (0)
+
+
+#endif /* _MACH_FMC_H_ */