ARM: keystone: ddr3: workaround for ddr3a/3b memory issue

This patch implements a workaround to fix DDR3 memory issue.
The code for workaround detects PGSR0 errors and then preps for
and executes a software-controlled hard reset.In board_early_init,
where logic has been added to identify whether or not the previous
reset was a PORz. PLL initialization is skipped in the case of a
software-controlled hard reset.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Keegan Garcia <kgarcia@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>

arch/arm/cpu/armv7/keystone/ddr3.c

@@ -10,6 +10,7 @@
 #include <asm/io.h>
 #include <common.h>
 #include <asm/arch/ddr3.h>
+#include <asm/arch/psc_defs.h>
 
 void ddr3_init_ddrphy(u32 base, struct ddr3_phy_config *phy_cfg)
 {
@@ -86,3 +87,77 @@ void ddr3_reset_ddrphy(void)
 	tmp &= ~KS2_DDR3_PLLCTRL_PHY_RESET;
 	__raw_writel(tmp, KS2_DDR3APLLCTL1);
 }
+
+#ifdef CONFIG_SOC_K2HK
+/**
+ * ddr3_reset_workaround - reset workaround in case if leveling error
+ * detected for PG 1.0 and 1.1 k2hk SoCs
+ */
+void ddr3_err_reset_workaround(void)
+{
+	unsigned int tmp;
+	unsigned int tmp_a;
+	unsigned int tmp_b;
+
+	/*
+	 * Check for PGSR0 error bits of DDR3 PHY.
+	 * Check for WLERR, QSGERR, WLAERR,
+	 * RDERR, WDERR, REERR, WEERR error to see if they are set or not
+	 */
+	tmp_a = __raw_readl(KS2_DDR3A_DDRPHYC + KS2_DDRPHY_PGSR0_OFFSET);
+	tmp_b = __raw_readl(KS2_DDR3B_DDRPHYC + KS2_DDRPHY_PGSR0_OFFSET);
+
+	if (((tmp_a & 0x0FE00000) != 0) || ((tmp_b & 0x0FE00000) != 0)) {
+		printf("DDR Leveling Error Detected!\n");
+		printf("DDR3A PGSR0 = 0x%x\n", tmp_a);
+		printf("DDR3B PGSR0 = 0x%x\n", tmp_b);
+
+		/*
+		 * Write Keys to KICK registers to enable writes to registers
+		 * in boot config space
+		 */
+		__raw_writel(KS2_KICK0_MAGIC, KS2_KICK0);
+		__raw_writel(KS2_KICK1_MAGIC, KS2_KICK1);
+
+		/*
+		 * Move DDR3A Module out of reset isolation by setting
+		 * MDCTL23[12] = 0
+		 */
+		tmp_a = __raw_readl(KS2_PSC_BASE +
+				    PSC_REG_MDCTL(KS2_LPSC_EMIF4F_DDR3A));
+
+		tmp_a = PSC_REG_MDCTL_SET_RESET_ISO(tmp_a, 0);
+		__raw_writel(tmp_a, KS2_PSC_BASE +
+			     PSC_REG_MDCTL(KS2_LPSC_EMIF4F_DDR3A));
+
+		/*
+		 * Move DDR3B Module out of reset isolation by setting
+		 * MDCTL24[12] = 0
+		 */
+		tmp_b = __raw_readl(KS2_PSC_BASE +
+				    PSC_REG_MDCTL(KS2_LPSC_EMIF4F_DDR3B));
+		tmp_b = PSC_REG_MDCTL_SET_RESET_ISO(tmp_b, 0);
+		__raw_writel(tmp_b, KS2_PSC_BASE +
+			     PSC_REG_MDCTL(KS2_LPSC_EMIF4F_DDR3B));
+
+		/*
+		 * Write 0x5A69 Key to RSTCTRL[15:0] to unlock writes
+		 * to RSTCTRL and RSTCFG
+		 */
+		tmp = __raw_readl(KS2_RSTCTRL);
+		tmp &= KS2_RSTCTRL_MASK;
+		tmp |= KS2_RSTCTRL_KEY;
+		__raw_writel(tmp, KS2_RSTCTRL);
+
+		/*
+		 * Set PLL Controller to drive hard reset on SW trigger by
+		 * setting RSTCFG[13] = 0
+		 */
+		tmp = __raw_readl(KS2_RSTCTRL_RSCFG);
+		tmp &= ~KS2_RSTYPE_PLL_SOFT;
+		__raw_writel(tmp, KS2_RSTCTRL_RSCFG);
+
+		reset_cpu(0);
+	}
+}
+#endif

arch/arm/include/asm/arch-keystone/ddr3.h

@@ -50,6 +50,7 @@ struct ddr3_emif_config {
 
 void ddr3_init(void);
 void ddr3_reset_ddrphy(void);
+void ddr3_err_reset_workaround(void);
 void ddr3_init_ddrphy(u32 base, struct ddr3_phy_config *phy_cfg);
 void ddr3_init_ddremif(u32 base, struct ddr3_emif_config *emif_cfg);
 

arch/arm/include/asm/arch-keystone/hardware.h

@@ -121,9 +121,11 @@ typedef volatile unsigned int   *dv_reg_p;
 #define KS2_CLOCK_BASE			KS2_PLL_CNTRL_BASE
 #define KS2_RSTCTRL_RSTYPE		(KS2_PLL_CNTRL_BASE + 0xe4)
 #define KS2_RSTCTRL			(KS2_PLL_CNTRL_BASE + 0xe8)
+#define KS2_RSTCTRL_RSCFG		(KS2_PLL_CNTRL_BASE + 0xec)
 #define KS2_RSTCTRL_KEY			0x5a69
 #define KS2_RSTCTRL_MASK		0xffff0000
 #define KS2_RSTCTRL_SWRST		0xfffe0000
+#define KS2_RSTYPE_PLL_SOFT		BIT(13)
 
 /* SPI */
 #define KS2_SPI0_BASE			0x21000400

board/ti/ks2_evm/ddr3_k2hk.c

@@ -81,4 +81,8 @@ void ddr3_init(void)
 		while (1)
 			;
 	}
+
+	/* Apply the workaround for PG 1.0 and 1.1 Silicons */
+	if (cpu_revision() <= 1)
+		ddr3_err_reset_workaround();
 }