arm: am437x: Enable hardware leveling for EMIF

Switch to using hardware leveling for certain parameters on the EMIF
rather than using precalculated values.  Doing this also means we have a
common place now between am437x and am335x for setting
emif_sdram_ref_ctrl with a value for the correct delay length.

Tested-by: Felipe Balbi <balbi@ti.com>
Tested-by: Tom Rini <trini@ti.com>
Signed-off-by: James Doublesin <doublesin@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 93 insertions, 46 deletions

diff --git a/arch/arm/cpu/armv7/am33xx/ddr.c b/arch/arm/cpu/armv7/am33xx/ddr.c
index fc66872..85cceae 100644
--- a/arch/arm/cpu/armv7/am33xx/ddr.c
+++ b/arch/arm/cpu/armv7/am33xx/ddr.c
@@ -76,13 +76,13 @@ static void configure_mr(int nr, u32 cs)
 }
 
 /*
- * Configure EMIF4D5 registers and MR registers
+ * Configure EMIF4D5 registers and MR registers For details about these magic
+ * values please see the EMIF registers section of the TRM.
  */
 void config_sdram_emif4d5(const struct emif_regs *regs, int nr)
 {
 	writel(0xA0, &emif_reg[nr]->emif_pwr_mgmt_ctrl);
 	writel(0xA0, &emif_reg[nr]->emif_pwr_mgmt_ctrl_shdw);
-	writel(0x1, &emif_reg[nr]->emif_iodft_tlgc);
 	writel(regs->zq_config, &emif_reg[nr]->emif_zq_config);
 
 	writel(regs->temp_alert_config, &emif_reg[nr]->emif_temp_alert_config);
@@ -106,10 +106,45 @@ void config_sdram_emif4d5(const struct emif_regs *regs, int nr)
 		writel(regs->emif_cos_config, &emif_reg[nr]->emif_cos_config);
 	}
 
-	writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl);
-	writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl_shdw);
+	/*
+	 * Sequence to ensure that the PHY is in a known state prior to
+	 * startting hardware leveling.  Also acts as to latch some state from
+	 * the EMIF into the PHY.
+	 */
+	writel(0x2011, &emif_reg[nr]->emif_iodft_tlgc);
+	writel(0x2411, &emif_reg[nr]->emif_iodft_tlgc);
+	writel(0x2011, &emif_reg[nr]->emif_iodft_tlgc);
+
+	clrbits_le32(&emif_reg[nr]->emif_sdram_ref_ctrl,
+			EMIF_REG_INITREF_DIS_MASK);
+
 	writel(regs->sdram_config, &emif_reg[nr]->emif_sdram_config);
 	writel(regs->sdram_config, &cstat->secure_emif_sdram_config);
+	writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl);
+	writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl_shdw);
+
+	/* Perform hardware leveling. */
+	udelay(1000);
+	writel(readl(&emif_reg[nr]->emif_ddr_ext_phy_ctrl_36) |
+	       0x100, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_36);
+	writel(readl(&emif_reg[nr]->emif_ddr_ext_phy_ctrl_36_shdw) |
+	       0x100, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_36_shdw);
+
+	writel(0x80000000, &emif_reg[nr]->emif_rd_wr_lvl_rmp_ctl);
+
+	/* Enable read leveling */
+	writel(0x80000000, &emif_reg[nr]->emif_rd_wr_lvl_ctl);
+
+	/*
+	 * Enable full read and write leveling.  Wait for read and write
+	 * leveling bit to clear RDWRLVLFULL_START bit 31
+	 */
+	while((readl(&emif_reg[nr]->emif_rd_wr_lvl_ctl) & 0x80000000) != 0)
+		;
+
+	/* Check the timeout register to see if leveling is complete */
+	if((readl(&emif_reg[nr]->emif_status) & 0x70) != 0)
+		puts("DDR3 H/W leveling incomplete with errors\n");
 
 	if (emif_sdram_type() == EMIF_SDRAM_TYPE_LPDDR2) {
 		configure_mr(nr, 0);
@@ -123,21 +158,15 @@ void config_sdram_emif4d5(const struct emif_regs *regs, int nr)
 void config_sdram(const struct emif_regs *regs, int nr)
 {
 	if (regs->zq_config) {
-		/*
-		 * A value of 0x2800 for the REF CTRL will give us
-		 * about 570us for a delay, which will be long enough
-		 * to configure things.
-		 */
-		writel(0x2800, &emif_reg[nr]->emif_sdram_ref_ctrl);
 		writel(regs->zq_config, &emif_reg[nr]->emif_zq_config);
 		writel(regs->sdram_config, &cstat->secure_emif_sdram_config);
 		writel(regs->sdram_config, &emif_reg[nr]->emif_sdram_config);
 		writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl);
 		writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl_shdw);
 	}
+	writel(regs->sdram_config, &emif_reg[nr]->emif_sdram_config);
 	writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl);
 	writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl_shdw);
-	writel(regs->sdram_config, &emif_reg[nr]->emif_sdram_config);
 }
 
 /**
@@ -153,46 +182,55 @@ void set_sdram_timings(const struct emif_regs *regs, int nr)
 	writel(regs->sdram_tim3, &emif_reg[nr]->emif_sdram_tim_3_shdw);
 }
 
-void __weak emif_get_ext_phy_ctrl_const_regs(const u32 **regs, u32 *size)
-{
-}
-
 /*
- * Configure EXT PHY registers
+ * Configure EXT PHY registers for hardware leveling
  */
 static void ext_phy_settings(const struct emif_regs *regs, int nr)
 {
-	u32 *ext_phy_ctrl_base = 0;
-	u32 *emif_ext_phy_ctrl_base = 0;
-	const u32 *ext_phy_ctrl_const_regs;
-	u32 i = 0;
-	u32 size;
-
-	ext_phy_ctrl_base = (u32 *)&(regs->emif_ddr_ext_phy_ctrl_1);
-	emif_ext_phy_ctrl_base =
-			(u32 *)&(emif_reg[nr]->emif_ddr_ext_phy_ctrl_1);
-
-	/* Configure external phy control timing registers */
-	for (i = 0; i < EMIF_EXT_PHY_CTRL_TIMING_REG; i++) {
-		writel(*ext_phy_ctrl_base, emif_ext_phy_ctrl_base++);
-		/* Update shadow registers */
-		writel(*ext_phy_ctrl_base++, emif_ext_phy_ctrl_base++);
-	}
-
 	/*
-	 * external phy 6-24 registers do not change with
-	 * ddr frequency
+	 * Enable hardware leveling on the EMIF.  For details about these
+	 * magic values please see the EMIF registers section of the TRM.
 	 */
-	emif_get_ext_phy_ctrl_const_regs(&ext_phy_ctrl_const_regs, &size);
-
-	if (!size)
-		return;
+	writel(0x08020080, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_1);
+	writel(0x08020080, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_1_shdw);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_22);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_22_shdw);
+	writel(0x00600020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_23);
+	writel(0x00600020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_23_shdw);
+	writel(0x40010080, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_24);
+	writel(0x40010080, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_24_shdw);
+	writel(0x08102040, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_25);
+	writel(0x08102040, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_25_shdw);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_26);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_26_shdw);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_27);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_27_shdw);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_28);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_28_shdw);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_29);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_29_shdw);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_30);
+	writel(0x00200020, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_30_shdw);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_31);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_31_shdw);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_32);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_32_shdw);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_33);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_33_shdw);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_34);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_34_shdw);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_35);
+	writel(0x00000000, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_35_shdw);
+	writel(0x000000FF, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_36);
+	writel(0x000000FF, &emif_reg[nr]->emif_ddr_ext_phy_ctrl_36_shdw);
 
-	for (i = 0; i < size; i++) {
-		writel(ext_phy_ctrl_const_regs[i], emif_ext_phy_ctrl_base++);
-		/* Update shadow registers */
-		writel(ext_phy_ctrl_const_regs[i], emif_ext_phy_ctrl_base++);
-	}
+	/*
+	 * Sequence to ensure that the PHY is again in a known state after
+	 * hardware leveling.
+	 */
+	writel(0x2011, &emif_reg[nr]->emif_iodft_tlgc);
+	writel(0x2411, &emif_reg[nr]->emif_iodft_tlgc);
+	writel(0x2011, &emif_reg[nr]->emif_iodft_tlgc);
 }
 
 /**
@@ -201,11 +239,17 @@ static void ext_phy_settings(const struct emif_regs *regs, int nr)
 void config_ddr_phy(const struct emif_regs *regs, int nr)
 {
 	/*
-	 * disable initialization and refreshes for now until we
+	 * Disable initialization and refreshes for now until we
 	 * finish programming EMIF regs.
+	 * Also set time between rising edge of DDR_RESET to rising
+	 * edge of DDR_CKE to > 500us per memory spec.
 	 */
+#ifndef CONFIG_AM43XX
 	setbits_le32(&emif_reg[nr]->emif_sdram_ref_ctrl,
 		     EMIF_REG_INITREF_DIS_MASK);
+#endif
+	if (regs->zq_config)
+		writel(0x80003100, &emif_reg[nr]->emif_sdram_ref_ctrl);
 
 	writel(regs->emif_ddr_phy_ctlr_1,
 		&emif_reg[nr]->emif_ddr_phy_ctrl_1);
diff --git a/arch/arm/cpu/armv7/am33xx/emif4.c b/arch/arm/cpu/armv7/am33xx/emif4.c
index 8b7527c..9cf816c 100644
--- a/arch/arm/cpu/armv7/am33xx/emif4.c
+++ b/arch/arm/cpu/armv7/am33xx/emif4.c
@@ -112,17 +112,20 @@ void config_ddr(unsigned int pll, const struct ctrl_ioregs *ioregs,
 
 	/* Set CKE to be controlled by EMIF/DDR PHY */
 	writel(DDR_CKE_CTRL_NORMAL, &ddrctrl->ddrckectrl);
+
 #endif
 #ifdef CONFIG_AM43XX
 	writel(readl(&cm_device->cm_dll_ctrl) & ~0x1, &cm_device->cm_dll_ctrl);
 	while ((readl(&cm_device->cm_dll_ctrl) & CM_DLL_READYST) == 0)
 		;
-	writel(0x80000000, &ddrctrl->ddrioctrl);
 
 	config_io_ctrl(ioregs);
 
 	/* Set CKE to be controlled by EMIF/DDR PHY */
 	writel(DDR_CKE_CTRL_NORMAL, &ddrctrl->ddrckectrl);
+
+	/* Allow EMIF to control DDR_RESET */
+	writel(0x00000000, &ddrctrl->ddrioctrl);
 #endif
 
 	/* Program EMIF instance */