mediatek/mt8183: Add DDR driver of software impedance part

BUG=b:80501386
BRANCH=none
TEST=Boots correctly on Kukui, and inits DRAM successfully with related
     patches.

Change-Id: I42a33ffb66ffa2f938f85484ffc3a0d3788816b3
Signed-off-by: Huayang Duan <huayang.duan@mediatek.com>
Reviewed-on: https://review.coreboot.org/28837
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>

src/soc/mediatek/mt8183/Makefile.inc

@@ -25,6 +25,7 @@ verstage-y += ../common/wdt.c
 romstage-y += auxadc.c
 romstage-y += ../common/cbmem.c emi.c
 romstage-y += dramc_init_setting.c
+romstage-y += dramc_pi_basic_api.c
 romstage-y += memory.c
 romstage-y += ../common/gpio.c gpio.c
 romstage-y += ../common/mmu_operations.c mmu_operations.c

src/soc/mediatek/mt8183/dramc_pi_basic_api.c

@@ -0,0 +1,111 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/io.h>
+#include <delay.h>
+#include <soc/emi.h>
+#include <soc/dramc_register.h>
+#include <soc/dramc_pi_api.h>
+
+static void sw_imp_cal_vref_sel(u8 term_option, u8 impcal_stage)
+{
+	u8 vref_sel = 0;
+
+	if (term_option == 1)
+		vref_sel = IMP_LP4X_TERM_VREF_SEL;
+	else {
+		switch (impcal_stage) {
+		case IMPCAL_STAGE_DRVP:
+			vref_sel = IMP_DRVP_LP4X_UNTERM_VREF_SEL;
+			break;
+		case IMPCAL_STAGE_DRVN:
+			vref_sel = IMP_DRVN_LP4X_UNTERM_VREF_SEL;
+			break;
+		default:
+			vref_sel = IMP_TRACK_LP4X_UNTERM_VREF_SEL;
+			break;
+		}
+	}
+
+	clrsetbits_le32(&ch[0].phy.shu[0].ca_cmd[11], 0x3f << 8, vref_sel << 8);
+}
+
+void dramc_sw_impedance(const struct sdram_params *params)
+{
+	u8 term = 0, ca_term = ODT_OFF, dq_term = ODT_ON;
+	u32 sw_impedance[2][4] = {0};
+
+	for (term = 0; term < 2; term++)
+		for (u8 i = 0; i < 4; i++)
+			sw_impedance[term][i] = params->impedance[term][i];
+
+	sw_impedance[ODT_OFF][2] = sw_impedance[ODT_ON][2];
+	sw_impedance[ODT_OFF][3] = sw_impedance[ODT_ON][3];
+
+	clrsetbits_le32(&ch[0].phy.shu[0].ca_cmd[11], 0xff, 0x3);
+	sw_imp_cal_vref_sel(dq_term, IMPCAL_STAGE_DRVP);
+
+	/* DQ */
+	clrsetbits_le32(&ch[0].ao.shu[0].drving[0], (0x1f << 5) | (0x1f << 0),
+		(sw_impedance[dq_term][0] << 5) |
+		(sw_impedance[dq_term][1] << 0));
+	clrsetbits_le32(&ch[0].ao.shu[0].drving[1],
+		(0x1f << 25)|(0x1f << 20) | (1 << 31),
+		(sw_impedance[dq_term][0] << 25) |
+		(sw_impedance[dq_term][1] << 20) | (!dq_term << 31));
+	clrsetbits_le32(&ch[0].ao.shu[0].drving[2], (0x1f << 5) | (0x1f << 0),
+		(sw_impedance[dq_term][2] << 5) |
+		(sw_impedance[dq_term][3] << 0));
+	clrsetbits_le32(&ch[0].ao.shu[0].drving[3], (0x1f << 25) | (0x1f << 20),
+		(sw_impedance[dq_term][2] << 25) |
+		(sw_impedance[dq_term][3] << 20));
+
+	/* DQS */
+	for (u8 i = 0; i <= 2; i += 2) {
+		clrsetbits_le32(&ch[0].ao.shu[0].drving[i],
+			(0x1f << 25) | (0x1f << 20),
+			(sw_impedance[dq_term][i] << 25) |
+			(sw_impedance[dq_term][i + 1] << 20));
+		clrsetbits_le32(&ch[0].ao.shu[0].drving[i],
+			(0x1f << 15) | (0x1f << 10),
+			(sw_impedance[dq_term][i] << 15) |
+			(sw_impedance[dq_term][i + 1] << 10));
+	}
+
+	/* CMD & CLK */
+	for (u8 i = 1; i <= 3; i += 2) {
+		clrsetbits_le32(&ch[0].ao.shu[0].drving[i],
+			(0x1f << 15) | (0x1f << 10),
+			(sw_impedance[ca_term][i - 1] << 15) |
+			(sw_impedance[ca_term][i] << 10));
+		clrsetbits_le32(&ch[0].ao.shu[0].drving[i],
+			(0x1f << 5) | (0x1f << 0),
+			(sw_impedance[ca_term][i - 1] << 5) |
+			(sw_impedance[ca_term][i] << 0));
+	}
+
+	clrsetbits_le32(&ch[0].phy.shu[0].ca_cmd[11], 0x1f << 17,
+		sw_impedance[ca_term][0] << 17);
+	clrsetbits_le32(&ch[0].phy.shu[0].ca_cmd[11], 0x1f << 22,
+		sw_impedance[ca_term][1] << 22);
+
+	clrsetbits_le32(&ch[0].phy.shu[0].ca_cmd[3],
+		SHU1_CA_CMD3_RG_TX_ARCMD_PU_PRE_MASK,
+		1 << SHU1_CA_CMD3_RG_TX_ARCMD_PU_PRE_SHIFT);
+	clrbits_le32(&ch[0].phy.shu[0].ca_cmd[0],
+		SHU1_CA_CMD0_RG_TX_ARCLK_DRVN_PRE_MASK);
+
+	clrsetbits_le32(&ch[0].phy.shu[0].ca_dll[1], 0x1f << 16, 0x9 << 16);
+}

src/soc/mediatek/mt8183/emi.c

@@ -280,6 +280,7 @@ static void init_dram(const struct sdram_params *params)
 
 	dramc_set_broadcast(DRAMC_BROADCAST_ON);
 	dramc_init_pre_settings();
+	dramc_sw_impedance(params);
 
 	dramc_init();
 	emi_init2(params);

src/soc/mediatek/mt8183/include/soc/dramc_pi_api.h

@@ -39,6 +39,11 @@
 #define DRAMC_BROADCAST_OFF 0x0
 #define MAX_BACKUP_REG_CNT 32
 
+#define IMP_LP4X_TERM_VREF_SEL		0x1b
+#define IMP_DRVP_LP4X_UNTERM_VREF_SEL	0x1a
+#define IMP_DRVN_LP4X_UNTERM_VREF_SEL	0x16
+#define IMP_TRACK_LP4X_UNTERM_VREF_SEL	0x1a
+
 enum dram_te_op {
 	TE_OP_WRITE_READ_CHECK = 0,
 	TE_OP_READ_CHECK
@@ -133,4 +138,5 @@ void dramc_get_rank_size(u64 *dram_rank_size);
 void dramc_set_broadcast(u32 onoff);
 u32 dramc_get_broadcast(void);
 void dramc_init(void);
+void dramc_sw_impedance(const struct sdram_params *params);
 #endif /* _DRAMC_PI_API_MT8183_H */