Change in coreboot[master]: soc/intel/common/xhci: Add function to reset the XHCI host controller

[Subrata Banik (Code Review)]

Subrata Banik has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/63551 )

Change subject: soc/intel/common/xhci: Add function to reset the XHCI host controller
......................................................................

soc/intel/common/xhci: Add function to reset the XHCI host controller

This patch adds `xhci_host_reset()` to reset XHCI controller and the
scope of this function is with SMM hence, compiling xhci.c for SMM as
well.

Also, refactored `xhci.c` code to keep PCI enumeration within the scope
of `ramstage` alone hence, guarded with `ENV_RAMSTAGE` env_variable.

BUG=b:227289581
TEST=Able to perform a call from `xhci_host_reset` from S5 smi handler.

Signed-off-by: Subrata Banik 
Change-Id: Ie0dc0a64044f291893931726d26c08c8b964a3cc
---
M src/soc/intel/common/block/include/intelblocks/xhci.h
M src/soc/intel/common/block/xhci/Makefile.inc
M src/soc/intel/common/block/xhci/xhci.c
3 files changed, 28 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/51/63551/1

diff --git a/src/soc/intel/common/block/include/intelblocks/xhci.h b/src/soc/intel/common/block/include/intelblocks/xhci.h
index 1adcbc0..7e2b76e 100644
--- a/src/soc/intel/common/block/include/intelblocks/xhci.h
+++ b/src/soc/intel/common/block/include/intelblocks/xhci.h
@@ -46,6 +46,8 @@
 bool xhci_update_wake_event(const struct xhci_wake_info *wake_info,
    		    size_t wake_info_count);

+/* xhci_host_reset() - Function to reset the host controller */
+void xhci_host_reset(void);
 void soc_xhci_init(struct device *dev);

/*
diff --git a/src/soc/intel/common/block/xhci/Makefile.inc b/src/soc/intel/common/block/xhci/Makefile.inc
index d1c505e..831992a 100644
--- a/src/soc/intel/common/block/xhci/Makefile.inc
+++ b/src/soc/intel/common/block/xhci/Makefile.inc
@@ -1,4 +1,5 @@
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_XHCI) += xhci.c
 ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_XHCI_ELOG) += elog.c

+smm-$(CONFIG_SOC_INTEL_COMMON_BLOCK_XHCI) += xhci.c
 smm-$(CONFIG_SOC_INTEL_COMMON_BLOCK_XHCI_ELOG) += elog.c
diff --git a/src/soc/intel/common/block/xhci/xhci.c b/src/soc/intel/common/block/xhci/xhci.c
index 9317bb0..4933f84 100644
--- a/src/soc/intel/common/block/xhci/xhci.c
+++ b/src/soc/intel/common/block/xhci/xhci.c
@@ -13,9 +13,33 @@
 #define XHCI_USB2	2
 #define XHCI_USB3	3

+#define XHCI_USBCMD 0x80
+#define  USBCMD_HCRST (1 << 1)
+
 /* Current Connect Status */
 #define XHCI_STATUS_CCS		(1 << 0)

+static uint8_t *xhci_mem_base(void)
+{
+	uint32_t mem_base = pci_read_config32(PCH_DEV_XHCI, PCI_BASE_ADDRESS_0);
+
+	/* Check if the controller is disabled or not present */
+	if (mem_base == 0 || mem_base == 0xffffffff)
+		return 0;
+
+	return (uint8_t *)(mem_base & ~0xf);
+}
+
+void xhci_host_reset(void)
+{
+	uint8_t *xhci_base = xhci_mem_base();
+	if (!xhci_base)
+		return;
+
+	setbits8(xhci_base + XHCI_USBCMD, USBCMD_HCRST);
+}
+
+#if ENV_RAMSTAGE
 static bool is_usb_port_connected(const struct xhci_usb_info *info,
    		unsigned int port_type, unsigned int port_id)
 {
@@ -134,3 +158,4 @@
    .vendor	 = PCI_VID_INTEL,
    .devices	 = pci_device_ids,
 };
+#endif