google/grunt: Override BayHub EMMC driving strength

Careena EVT SanDisk EMMC sku has high fail rate of 0x5B reboot failure.
It'll need to increase 1.8V EMMC CLK/CMD, Data driving strength for
this issue.

CLK[6:4]
CMD,DATA[3:1]

original register value: 0x6B
enhanced: 0x7F

BUG=b:111964336
BRANCH=master
TEST=emerge-grunt coreboot
Change-Id: I3db38ff12c566c258895c6643008a0472ca528bb
Signed-off-by: Kevin Chiu <Kevin.Chiu@quantatw.com>
Reviewed-on: https://review.coreboot.org/27816
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3 files changed, 78 insertions, 22 deletions

diff --git a/src/drivers/generic/bayhub/bh720.c b/src/drivers/generic/bayhub/bh720.c
index 3e78b4f049..b689b679d0 100644
--- a/src/drivers/generic/bayhub/bh720.c
+++ b/src/drivers/generic/bayhub/bh720.c
@@ -21,28 +21,11 @@
 #include <device/pci.h>
 #include <device/pci_ids.h>
 #include "chip.h"
+#include "bh720.h"
 
-enum {
-	BH720_PROTECT			= 0xd0,
-	BH720_PROTECT_LOCK_OFF		= 0,
-	BH720_PROTECT_LOCK_ON		= BIT(0),
-	BH720_PROTECT_OFF		= 0,
-	BH720_PROTECT_ON		= BIT(31),
-
-	BH720_LINK_CTRL			= 0x90,
-	BH720_LINK_CTRL_L0_ENABLE	= BIT(0),
-	BH720_LINK_CTRL_L1_ENABLE	= BIT(1),
-	BH720_LINK_CTRL_CLKREQ		= BIT(8),
-
-	BH720_MISC2			= 0xf0,
-	BH720_MISC2_ASPM_DISABLE	= BIT(0),
-	BH720_MISC2_APSM_CLKREQ_L1	= BIT(7),
-	BH720_MISC2_APSM_PHY_L1		= BIT(10),
-	BH720_MISC2_APSM_MORE		= BIT(12),
-
-	BH720_RTD3_L1			= 0x3e0,
-	BH720_RTD3_L1_DISABLE_L1	= BIT(28),
-};
+__attribute__((weak)) void bh720_driving_strength(struct device *dev)
+{
+}
 
 static void bh720_init(struct device *dev)
 {
@@ -71,6 +54,8 @@ static void bh720_init(struct device *dev)
 		printk(BIOS_INFO, "BayHub BH720: Power-saving enabled (link_ctrl=%#x)\n",
 		       pci_read_config32(dev, BH720_LINK_CTRL));
 	}
+
+	bh720_driving_strength(dev);
 }
 
 static struct pci_operations pci_ops = {
diff --git a/src/drivers/generic/bayhub/bh720.h b/src/drivers/generic/bayhub/bh720.h
new file mode 100644
index 0000000000..b6fd2738cd
--- /dev/null
+++ b/src/drivers/generic/bayhub/bh720.h
@@ -0,0 +1,47 @@
+/*
+ * Driver for BayHub Technology BH720 PCI to eMMC 5.0 HS200 bridge
+ *
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 Google LLC.
+ *
+ * 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.
+ */
+
+enum {
+	BH720_PROTECT                   = 0xd0,
+	BH720_PROTECT_LOCK_OFF          = 0,
+	BH720_PROTECT_LOCK_ON           = BIT(0),
+	BH720_PROTECT_OFF               = 0,
+	BH720_PROTECT_ON                = BIT(31),
+
+	BH720_LINK_CTRL                 = 0x90,
+	BH720_LINK_CTRL_L0_ENABLE       = BIT(0),
+	BH720_LINK_CTRL_L1_ENABLE       = BIT(1),
+	BH720_LINK_CTRL_CLKREQ          = BIT(8),
+
+	BH720_MISC2                     = 0xf0,
+	BH720_MISC2_ASPM_DISABLE        = BIT(0),
+	BH720_MISC2_APSM_CLKREQ_L1      = BIT(7),
+	BH720_MISC2_APSM_PHY_L1         = BIT(10),
+	BH720_MISC2_APSM_MORE           = BIT(12),
+
+	BH720_MEM_RW_DATA               = 0x200,
+	BH720_MEM_RW_ADR                = 0x204,
+	BH720_MEM_ACCESS_EN             = 0x208,
+	BH720_PCR                       = 0x304,
+	BH720_PCR_DATA_CMD_DRV_MAX      = 7,
+	BH720_PCR_CLK_DRV_MAX           = 7,
+
+	BH720_RTD3_L1                   = 0x3e0,
+	BH720_RTD3_L1_DISABLE_L1        = BIT(28),
+};
+
+void bh720_driving_strength(struct device *dev);
diff --git a/src/mainboard/google/kahlee/variants/baseboard/mainboard.c b/src/mainboard/google/kahlee/variants/baseboard/mainboard.c
index 54743ef7c1..b1bd4928d2 100644
--- a/src/mainboard/google/kahlee/variants/baseboard/mainboard.c
+++ b/src/mainboard/google/kahlee/variants/baseboard/mainboard.c
@@ -17,7 +17,8 @@
 #include <baseboard/variants.h>
 #include <gpio.h>
 #include <variant/gpio.h>
-
+#include <device/pci.h>
+#include <drivers/generic/bayhub/bh720.h>
 
 uint8_t variant_board_sku(void)
 {
@@ -36,3 +37,26 @@ void variant_mainboard_suspend_resume(void)
 	gpio_set(GPIO_133, 0);
 }
 #endif
+
+void bh720_driving_strength(struct device *dev)
+{
+	u32 sdbar;
+	u32 bh720_pcr_data;
+
+	sdbar = pci_read_config32(dev, PCI_BASE_ADDRESS_1);
+
+	/* Enable Memory Access Function */
+	write32((void *)(sdbar + BH720_MEM_ACCESS_EN), 0x40000000);
+	write32((void *)(sdbar + BH720_MEM_RW_DATA), 0x80000000);
+	write32((void *)(sdbar + BH720_MEM_RW_ADR), 0x800000D0);
+
+	/* Read current EMMC 1.8V CLK/DATA,CMD driving strength */
+	write32((void *)(sdbar + BH720_MEM_RW_ADR), 0x40000304);
+	bh720_pcr_data = read32((void *)(sdbar + BH720_MEM_RW_DATA));
+
+	/* set EMMC 1.8V CLK/DATA,CMD the max level */
+	write32((void *)(sdbar + BH720_MEM_RW_DATA),
+		bh720_pcr_data | (BH720_PCR_CLK_DRV_MAX << 4) |
+		(BH720_PCR_DATA_CMD_DRV_MAX << 1));
+	write32((void *)(sdbar + BH720_MEM_RW_ADR), 0x80000304);
+}