ram: stm32: add stm32h7 support

STM32F7 and H7 shared the same SDRAM control block.
On STM32H7 few control bits has been added.
The current driver need some minor adaptation as FMC block
enable/disable for H7.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

drivers/ram/stm32_sdram.c

@@ -54,6 +54,12 @@ struct stm32_fmc_regs {
 	u32 sdsr;	/* SDRAM Status register */
 };
 
+/*
+ * NOR/PSRAM Control register BCR1
+ * FMC controller Enable, only availabe for H7
+ */
+#define FMC_BCR1_FMCEN		BIT(31)
+
 /* Control register SDCR */
 #define FMC_SDCR_RPIPE_SHIFT	13	/* RPIPE bit shift */
 #define FMC_SDCR_RBURST_SHIFT	12	/* RBURST bit shift */
@@ -123,6 +129,11 @@ enum stm32_fmc_bank {
 	MAX_SDRAM_BANK,
 };
 
+enum stm32_fmc_family {
+	STM32F7_FMC,
+	STM32H7_FMC,
+};
+
 struct bank_params {
 	struct stm32_sdram_control *sdram_control;
 	struct stm32_sdram_timing *sdram_timing;
@@ -134,6 +145,7 @@ struct stm32_sdram_params {
 	struct stm32_fmc_regs *base;
 	u8 no_sdram_banks;
 	struct bank_params bank_params[MAX_SDRAM_BANK];
+	enum stm32_fmc_family family;
 };
 
 #define SDRAM_MODE_BL_SHIFT	0
@@ -151,6 +163,10 @@ int stm32_sdram_init(struct udevice *dev)
 	u32 ref_count;
 	u8 i;
 
+	/* disable the FMC controller */
+	if (params->family == STM32H7_FMC)
+		clrbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);
+
 	for (i = 0; i < params->no_sdram_banks; i++) {
 		control = params->bank_params[i].sdram_control;
 		timing = params->bank_params[i].sdram_timing;
@@ -193,6 +209,7 @@ int stm32_sdram_init(struct udevice *dev)
 				| timing->txsr << FMC_SDTR_TXSR_SHIFT
 				| timing->tmrd << FMC_SDTR_TMRD_SHIFT,
 				&regs->sdtr2);
+
 		if (target_bank == SDRAM_BANK1)
 			ctb = FMC_SDCMR_BANK_1;
 		else
@@ -225,6 +242,10 @@ int stm32_sdram_init(struct udevice *dev)
 		writel(ref_count << 1, &regs->sdrtr);
 	}
 
+	/* enable the FMC controller */
+	if (params->family == STM32H7_FMC)
+		setbits_le32(&regs->bcr1, FMC_BCR1_FMCEN);
+
 	return 0;
 }
 
@@ -305,6 +326,7 @@ static int stm32_fmc_probe(struct udevice *dev)
 		return -EINVAL;
 
 	params->base = (struct stm32_fmc_regs *)addr;
+	params->family = dev_get_driver_data(dev);
 
 #ifdef CONFIG_CLK
 	struct clk clk;
@@ -337,7 +359,8 @@ static struct ram_ops stm32_fmc_ops = {
 };
 
 static const struct udevice_id stm32_fmc_ids[] = {
-	{ .compatible = "st,stm32-fmc" },
+	{ .compatible = "st,stm32-fmc", .data = STM32F7_FMC },
+	{ .compatible = "st,stm32h7-fmc", .data = STM32H7_FMC },
 	{ }
 };