soc/intel/apollolake: provide common LPDDR4 memory init

Instead of having the mainboards duplicate logic surrounding
LPDDR4 initialization provide helpers to do the heavy lifting.
It also handles the quirks of the FSP configuration which allows
the mainboard porting to focus on the schematic/design.

Change-Id: I686eb3097c33399a3b94af89237f7fe1b2d34c2f
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/14790
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>

3 files changed, 311 insertions, 0 deletions

diff --git a/src/soc/intel/apollolake/Makefile.inc b/src/soc/intel/apollolake/Makefile.inc
index 5cc4f26099..240d3c2a69 100644
--- a/src/soc/intel/apollolake/Makefile.inc
+++ b/src/soc/intel/apollolake/Makefile.inc
@@ -26,6 +26,7 @@ romstage-y += gpio.c
 romstage-$(CONFIG_SOC_UART_DEBUG) += uart_early.c
 romstage-y += lpc_lib.c
 romstage-y += memmap.c
+romstage-y += meminit.c
 romstage-y += mmap_boot.c
 romstage-y += tsc_freq.c
 romstage-y += pmutil.c
diff --git a/src/soc/intel/apollolake/include/soc/meminit.h b/src/soc/intel/apollolake/include/soc/meminit.h
new file mode 100644
index 0000000000..18c59a4768
--- /dev/null
+++ b/src/soc/intel/apollolake/include/soc/meminit.h
@@ -0,0 +1,97 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google 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.
+ */
+
+#ifndef _SOC_APOLLOLAKE_MEMINIT_H_
+#define _SOC_APOLLOLAKE_MEMINIT_H_
+
+#include <stdint.h>
+
+/*
+ * LPDDR4 helper routines for configuring the memory UPD for LPDDR4 operation.
+ * There are 4 physical LPDDR4 channels each 32-bits wide. There are 2 logical
+ * channels using 2 physical channels together to form a 64-bit interface to
+ * memory for each logical channel.
+ */
+
+enum {
+	LP4_PHYS_CH0A,
+	LP4_PHYS_CH0B,
+	LP4_PHYS_CH1A,
+	LP4_PHYS_CH1B,
+	LP4_NUM_PHYS_CHANNELS,
+};
+
+/* Logical channel identification. */
+enum {
+	LP4_LCH0,
+	LP4_LCH1,
+};
+
+/*
+ * The DQs within a physical channel can be bit-swizzled within each byte.
+ * Within a channel the bytes can be swapped, but the DQs need to be routed
+ * with the corresponding DQS (strobe).
+ */
+enum {
+	LP4_DQS0,
+	LP4_DQS1,
+	LP4_DQS2,
+	LP4_DQS3,
+	LP4_NUM_BYTE_LANES,
+	DQ_BITS_PER_DQS = 8,
+};
+
+enum {
+				/* RL-tRCD-tRP */
+	LP4_SPEED_1600 = 1600,	/* 14-15-15 */
+	LP4_SPEED_2133 = 2133,	/* 20-20-20 */
+	LP4_SPEED_2400 = 2400,	/* 24-22-22 */
+};
+
+/* LPDDR4 module density in bits. */
+enum {
+	LP4_8Gb_DENSITY,
+	LP4_12Gb_DESNITY,
+	LP4_16Gb_DENSITY,
+};
+
+/* Provide bit swizzling per DQS and byte swapping within a channel. */
+struct lpddr4_chan_swizzle_cfg {
+	uint8_t dqs[LP4_NUM_BYTE_LANES][DQ_BITS_PER_DQS];
+};
+
+struct lpddr4_swizzle_cfg {
+	struct lpddr4_chan_swizzle_cfg phys[LP4_NUM_PHYS_CHANNELS];
+};
+
+struct FSP_M_CONFIG;
+
+/*
+ * Initialize default LPDDR4 settings with provided speed. No logical channels
+ * are enabled. Subsequent calls to logical channel enabling are required.
+ */
+void meminit_lpddr4(struct FSP_M_CONFIG *cfg, int speed);
+
+/*
+ * Enable logical channel providing the full lpddr4_swizzle_config to
+ * fill in per channel swizzle definitions. This assumes a 64-bit wide
+ * memory width per logical channel -- i.e. 2 physical channels are configured
+ * to the memory reference code.
+ */
+void meminit_lpddr4_enable_channel(struct FSP_M_CONFIG *cfg, int logical_chan,
+					int device_density,
+					const struct lpddr4_swizzle_cfg *scfg);
+
+#endif /* _SOC_APOLLOLAKE_MEMINIT_H_ */
diff --git a/src/soc/intel/apollolake/meminit.c b/src/soc/intel/apollolake/meminit.c
new file mode 100644
index 0000000000..8b661c9568
--- /dev/null
+++ b/src/soc/intel/apollolake/meminit.c
@@ -0,0 +1,213 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google 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 <console/console.h>
+#include <soc/meminit.h>
+#include <stddef.h> /* required for FspmUpd.h */
+#include <soc/fsp/FspmUpd.h>
+#include <string.h>
+
+static void set_lpddr4_defaults(struct FSP_M_CONFIG *cfg)
+{
+	/* Enable memory down BGA since it's the only LPDDR4 packaging. */
+	cfg->Package = 1;
+	cfg->MemoryDown = 1;
+
+	cfg->ScramblerSupport = 1;
+	cfg->ChannelHashMask = 0x36;
+	cfg->SliceHashMask = 0x9;
+	cfg->InterleavedMode = 2;
+	cfg->ChannelsSlicesEnable = 0;
+	cfg->MinRefRate2xEnable = 0;
+	cfg->DualRankSupportEnable = 1;
+	/* Don't enforce a memory size limit. */
+	cfg->MemorySizeLimit = 0;
+	/* Use a 2GiB I/O hole -- field is in MiB units. */
+	cfg->LowMemoryMaxValue = 2 * (GiB/MiB);
+	/* No restrictions on memory above 4GiB */
+	cfg->HighMemoryMaxValue = 0;
+
+	/* Always default to attempt to use saved training data. */
+	cfg->DisableFastBoot = 0;
+
+	/* LPDDR4 is memory down so no SPD addresses. */
+	cfg->DIMM0SPDAddress = 0;
+	cfg->DIMM1SPDAddress = 0;
+
+	/* Clear all the rank enables. */
+	cfg->Ch0_RankEnable = 0x0;
+	cfg->Ch1_RankEnable = 0x0;
+	cfg->Ch2_RankEnable = 0x0;
+	cfg->Ch3_RankEnable = 0x0;
+
+	/*
+	 * Set the device width to x16 which is half a LPDDR4 module as that's
+	 * what the reference code expects.
+	 */
+	cfg->Ch0_DeviceWidth = 0x1;
+	cfg->Ch1_DeviceWidth = 0x1;
+	cfg->Ch2_DeviceWidth = 0x1;
+	cfg->Ch3_DeviceWidth = 0x1;
+
+	/*
+	 * Enable bank hashing (bit 1) and rank interleaving (bit 0) with
+	 * a 1KiB address mapping (bits 5:4).
+	 */
+	cfg->Ch0_Option = 0x3;
+	cfg->Ch1_Option = 0x3;
+	cfg->Ch2_Option = 0x3;
+	cfg->Ch3_Option = 0x3;
+
+	/* Weak on-die termination. */
+	cfg->Ch0_OdtConfig = 0;
+	cfg->Ch1_OdtConfig = 0;
+	cfg->Ch2_OdtConfig = 0;
+	cfg->Ch3_OdtConfig = 0;
+}
+
+void meminit_lpddr4(struct FSP_M_CONFIG *cfg, int speed)
+{
+	uint8_t profile;
+
+	switch (speed) {
+	case LP4_SPEED_1600:
+		profile = 0x9;
+		break;
+	case LP4_SPEED_2133:
+		profile = 0xa;
+		break;
+	case LP4_SPEED_2400:
+		profile = 0xb;
+		break;
+	default:
+		printk(BIOS_WARNING, "Invalid LPDDR4 speed: %d\n", speed);
+		/* Set defaults. */
+		speed = LP4_SPEED_1600;
+		profile = 0x9;
+	}
+
+	printk(BIOS_INFO, "LP4DDR speed is %dMHz\n", speed);
+	cfg->Profile = profile;
+
+	set_lpddr4_defaults(cfg);
+}
+
+static void enable_logical_chan0(struct FSP_M_CONFIG *cfg, int device_density,
+					const struct lpddr4_swizzle_cfg *scfg)
+{
+	const struct lpddr4_chan_swizzle_cfg *chan;
+	/* Number of bytes to copy per DQS. */
+	const size_t sz = DQ_BITS_PER_DQS;
+
+	/*
+	 * Logical channel 0 is comprised of physical channel 0 and 1.
+	 * Physical channel 0 is comprised of the CH0_DQB signals.
+	 * Physical channel 1 is comprised of the CH0_DQA signals.
+	 */
+	cfg->Ch0_DramDensity = device_density;
+	cfg->Ch1_DramDensity = device_density;
+	/* Enable rank 0 on both channels. */
+	cfg->Ch0_RankEnable = 1;
+	cfg->Ch1_RankEnable = 1;
+
+	/*
+	 * CH0_DQB byte lanes in the bit swizzle configuration field are
+	 * not 1:1. The mapping within the swizzling field is:
+	 *   indicies [0:7]   - byte lane 1 (DQS1) DQ[8:15]
+	 *   indicies [8:15]  - byte lane 0 (DQS0) DQ[0:7]
+	 *   indicies [16:23] - byte lane 3 (DQS3) DQ[24:31]
+	 *   indicies [24:31] - byte lane 2 (DQS2) DQ[16:23]
+	 */
+	chan = &scfg->phys[LP4_PHYS_CH0B];
+	memcpy(&cfg->Ch0_Bit_swizzling[0], &chan->dqs[LP4_DQS1], sz);
+	memcpy(&cfg->Ch0_Bit_swizzling[8], &chan->dqs[LP4_DQS0], sz);
+	memcpy(&cfg->Ch0_Bit_swizzling[16], &chan->dqs[LP4_DQS3], sz);
+	memcpy(&cfg->Ch0_Bit_swizzling[24], &chan->dqs[LP4_DQS2], sz);
+
+	/*
+	 * CH0_DQA byte lanes in the bit swizzle configuration field are 1:1.
+	 */
+	chan = &scfg->phys[LP4_PHYS_CH0A];
+	memcpy(&cfg->Ch1_Bit_swizzling[0], &chan->dqs[LP4_DQS0], sz);
+	memcpy(&cfg->Ch1_Bit_swizzling[8], &chan->dqs[LP4_DQS1], sz);
+	memcpy(&cfg->Ch1_Bit_swizzling[16], &chan->dqs[LP4_DQS2], sz);
+	memcpy(&cfg->Ch1_Bit_swizzling[24], &chan->dqs[LP4_DQS3], sz);
+}
+
+static void enable_logical_chan1(struct FSP_M_CONFIG *cfg, int device_density,
+					const struct lpddr4_swizzle_cfg *scfg)
+{
+	const struct lpddr4_chan_swizzle_cfg *chan;
+	/* Number of bytes to copy per DQS. */
+	const size_t sz = DQ_BITS_PER_DQS;
+
+	/*
+	 * Logical channel 1 is comprised of physical channel 2 and 3.
+	 * Physical channel 2 is comprised of the CH1_DQB signals.
+	 * Physical channel 3 is comprised of the CH1_DQA signals.
+	 */
+	cfg->Ch2_DramDensity = device_density;
+	cfg->Ch3_DramDensity = device_density;
+	/* Enable rank 0 on both channels. */
+	cfg->Ch2_RankEnable = 1;
+	cfg->Ch3_RankEnable = 1;
+
+	/*
+	 * CH1_DQB byte lanes in the bit swizzle configuration field are
+	 * not 1:1. The mapping within the swizzling field is:
+	 *   indicies [0:7]   - byte lane 1 (DQS1) DQ[8:15]
+	 *   indicies [8:15]  - byte lane 0 (DQS0) DQ[0:7]
+	 *   indicies [16:23] - byte lane 3 (DQS3) DQ[24:31]
+	 *   indicies [24:31] - byte lane 2 (DQS2) DQ[16:23]
+	 */
+	chan = &scfg->phys[LP4_PHYS_CH1B];
+	memcpy(&cfg->Ch2_Bit_swizzling[0], &chan->dqs[LP4_DQS1], sz);
+	memcpy(&cfg->Ch2_Bit_swizzling[8], &chan->dqs[LP4_DQS0], sz);
+	memcpy(&cfg->Ch2_Bit_swizzling[16], &chan->dqs[LP4_DQS3], sz);
+	memcpy(&cfg->Ch2_Bit_swizzling[24], &chan->dqs[LP4_DQS2], sz);
+
+	/*
+	 * CH1_DQA byte lanes in the bit swizzle configuration field are 1:1.
+	 */
+	chan = &scfg->phys[LP4_PHYS_CH1A];
+	memcpy(&cfg->Ch3_Bit_swizzling[0], &chan->dqs[LP4_DQS0], sz);
+	memcpy(&cfg->Ch3_Bit_swizzling[8], &chan->dqs[LP4_DQS1], sz);
+	memcpy(&cfg->Ch3_Bit_swizzling[16], &chan->dqs[LP4_DQS2], sz);
+	memcpy(&cfg->Ch3_Bit_swizzling[24], &chan->dqs[LP4_DQS3], sz);
+}
+
+void meminit_lpddr4_enable_channel(struct FSP_M_CONFIG *cfg, int logical_chan,
+					int device_density,
+					const struct lpddr4_swizzle_cfg *scfg)
+{
+	if (device_density < LP4_8Gb_DENSITY ||
+		device_density > LP4_16Gb_DENSITY) {
+		printk(BIOS_ERR, "Invalid LPDDR4 density: %d\n",
+			device_density);
+		return;
+	}
+
+	switch (logical_chan) {
+	case LP4_LCH0:
+		enable_logical_chan0(cfg, device_density, scfg);
+		break;
+	case LP4_LCH1:
+		enable_logical_chan1(cfg, device_density, scfg);
+		break;
+	default:
+		printk(BIOS_ERR, "Invalid logical channel: %d\n", logical_chan);
+		break;
+	}
+}