From f0a865bd5579510a1fe287c1f274635f3cc0791d Mon Sep 17 00:00:00 2001
From: Weijie Gao <weijie.gao@mediatek.com>
Date: Thu, 12 Nov 2020 16:35:43 +0800
Subject: [PATCH] mips: mtmips: add support to initialize SDRAM

This patch adds support for mtmips SoCs to initialize the SDRAM.

Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
---
 arch/mips/mach-mtmips/ddr_init.c         | 59 ++++++++++++++++++++++++
 arch/mips/mach-mtmips/include/mach/ddr.h |  4 ++
 2 files changed, 63 insertions(+)

diff --git a/arch/mips/mach-mtmips/ddr_init.c b/arch/mips/mach-mtmips/ddr_init.c
index 6c6d0933f2..9c986daea6 100644
--- a/arch/mips/mach-mtmips/ddr_init.c
+++ b/arch/mips/mach-mtmips/ddr_init.c
@@ -15,6 +15,13 @@
 
 #define DDR_BW_TEST_PAT			0xaa5555aa
 
+static const u32 sdr_size_cfg1[] = {
+	[DRAM_8MB] = (1 << NUMROWS_S),
+	[DRAM_16MB] = (1 << NUMROWS_S) | (1 << NUMCOLS_S),
+	[DRAM_32MB] = (2 << NUMROWS_S) | (1 << NUMCOLS_S),
+	[DRAM_64MB] = (2 << NUMROWS_S) | (2 << NUMCOLS_S),
+};
+
 static const u32 dram_size[] = {
 	[DRAM_8MB] = SZ_8M,
 	[DRAM_16MB] = SZ_16M,
@@ -193,3 +200,55 @@ void ddr2_init(struct mc_ddr_init_param *param)
 	param->memsize = dram_size[sz];
 	param->bus_width = bw;
 }
+
+static void mc_sdr_init(void __iomem *memc, mc_reset_t mc_reset, u32 cfg0,
+			u32 cfg1)
+{
+	mc_reset(1);
+	__udelay(200);
+	mc_reset(0);
+
+	writel(cfg0, memc + MEMCTL_SDRAM_CFG0_REG);
+	writel(cfg1, memc + MEMCTL_SDRAM_CFG1_REG);
+
+	while (!(readl(memc + MEMCTL_SDRAM_CFG1_REG) & SDRAM_INIT_DONE))
+		;
+
+	clrsetbits_32(memc + MEMCTL_PWR_SAVE_CNT_REG, SR_TAR_CNT_M,
+		      1 << SR_TAR_CNT_S);
+
+	setbits_32(memc + MEMCTL_DDR_SELF_REFRESH_REG, SR_AUTO_EN);
+}
+
+void sdr_init(struct mc_ddr_init_param *param)
+{
+	enum mc_dram_size sz;
+	u32 cfg1;
+
+	cfg1 = param->sdr_cfg1 | SDRAM_INIT_START;
+	cfg1 &= ~(NUMCOLS_M | NUMROWS_M);
+
+	/* First initialization, determine SDR capacity */
+	mc_sdr_init(param->memc, param->mc_reset, param->sdr_cfg0,
+		    cfg1 | sdr_size_cfg1[DRAM_64MB]);
+
+	if (dram_addr_test_bit(9)) {
+		sz = DRAM_8MB;
+	} else {
+		if (dram_addr_test_bit(10)) {
+			if (dram_addr_test_bit(23))
+				sz = DRAM_16MB;
+			else
+				sz = DRAM_32MB;
+		} else {
+			sz = DRAM_64MB;
+		}
+	}
+
+	/* Final initialization */
+	mc_sdr_init(param->memc, param->mc_reset, param->sdr_cfg0,
+		    cfg1 | sdr_size_cfg1[sz]);
+
+	/* Return actual DDR configuration */
+	param->memsize = dram_size[sz];
+}
diff --git a/arch/mips/mach-mtmips/include/mach/ddr.h b/arch/mips/mach-mtmips/include/mach/ddr.h
index f92198137b..15ff66ace6 100644
--- a/arch/mips/mach-mtmips/include/mach/ddr.h
+++ b/arch/mips/mach-mtmips/include/mach/ddr.h
@@ -35,6 +35,9 @@ typedef void (*mc_reset_t)(int assert);
 struct mc_ddr_init_param {
 	void __iomem *memc;
 
+	u32 sdr_cfg0;
+	u32 sdr_cfg1;
+
 	u32 dq_dly;
 	u32 dqs_dly;
 
@@ -45,6 +48,7 @@ struct mc_ddr_init_param {
 	u32 bus_width;
 };
 
+void sdr_init(struct mc_ddr_init_param *param);
 void ddr1_init(struct mc_ddr_init_param *param);
 void ddr2_init(struct mc_ddr_init_param *param);
 void ddr_calibrate(void __iomem *memc, u32 memsize, u32 bw);