[PATCH 1/3] usb: host: xhci-plat: Add support for Exynos5/DWC3 specific variant
From: Marek Szyprowski
Date: Thu Jun 27 2019 - 03:17:53 EST
USB3.0 DRD PHY found in Exynos5 SoCs requires calibration to be done
after every HCD reset. This was initially handled by DWC3 core by commit
d8c80bb3b55b ("phy: exynos5-usbdrd: Calibrate LOS levels for
exynos5420/5800"), but it turned out that the mentioned patch worked only
by the pure luck and fixed only one use case.
PHY calibration was done in DWC3 driver, just before initializing XHCI
core. This approach was prone to a race. It worked for the fresh boot
case iff XHCI-plat driver was compiled into the kernel or it's module has
been loaded before DWC3 probe. In other cases (XHCI-plat module loaded on
demand after DWC3 probe or during suspend/resume cycle) - the
calibration was not performed at proper time and had no effect.
This patch creates Exynos5/DWC3 specific variant of XHCI-plat driver,
which takes care of proper PHY calibration after XHCI core reset, what
fixes all known use cases (XHCI driver compiled as module and loaded on
demand as well as during system suspend/resume cycle).
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/usb/host/Kconfig | 8 ++++++
drivers/usb/host/Makefile | 3 ++
drivers/usb/host/xhci-exynos.c | 51 ++++++++++++++++++++++++++++++++++
drivers/usb/host/xhci-exynos.h | 26 +++++++++++++++++
drivers/usb/host/xhci-plat.c | 38 ++++++++++++++++++++++++-
drivers/usb/host/xhci-plat.h | 2 ++
6 files changed, 127 insertions(+), 1 deletion(-)
create mode 100644 drivers/usb/host/xhci-exynos.c
create mode 100644 drivers/usb/host/xhci-exynos.h
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 40b5de597112..5a17a9b1fbff 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -53,6 +53,14 @@ config USB_XHCI_PLATFORM
If unsure, say N.
+config USB_XHCI_EXYNOS
+ tristate "xHCI support for Samsung Exynos SoCs"
+ depends on USB_XHCI_PLATFORM
+ depends on ARCH_EXYNOS || COMPILE_TEST
+ ---help---
+ Say 'Y' to enable the support for the xHCI host controller
+ found in Samsung Exynos ARM SoCs.
+
config USB_XHCI_HISTB
tristate "xHCI support for HiSilicon STB SoCs"
depends on USB_XHCI_PLATFORM && (ARCH_HISI || COMPILE_TEST)
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index 84514f71ae44..34afd6680751 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -30,6 +30,9 @@ endif
ifneq ($(CONFIG_USB_XHCI_RCAR), )
xhci-plat-hcd-y += xhci-rcar.o
endif
+ifneq ($(CONFIG_USB_XHCI_EXYNOS), )
+ xhci-plat-hcd-y += xhci-exynos.o
+endif
ifneq ($(CONFIG_DEBUG_FS),)
xhci-hcd-y += xhci-debugfs.o
diff --git a/drivers/usb/host/xhci-exynos.c b/drivers/usb/host/xhci-exynos.c
new file mode 100644
index 000000000000..446d33998382
--- /dev/null
+++ b/drivers/usb/host/xhci-exynos.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * xHCI host controller driver for Samsung Exynos5 SoCs
+ *
+ * Copyright (C) 2019 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+
+#include "xhci.h"
+#include "xhci-plat.h"
+#include "xhci-exynos.h"
+
+int xhci_exynos_init_quirk(struct usb_hcd *hcd)
+{
+ struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+ struct device *dev = hcd->self.controller;
+ struct xhci_plat_priv *xhci_priv = hcd_to_xhci_priv(hcd);
+ struct phy *usb2_generic_phy;
+ int ret;
+
+ usb2_generic_phy = devm_phy_get(dev->parent, "usb2-phy");
+ if (IS_ERR(usb2_generic_phy)) {
+ ret = PTR_ERR(usb2_generic_phy);
+ if (ret == -EPROBE_DEFER) {
+ return ret;
+ } else {
+ dev_err(dev, "no usb2 phy configured\n");
+ return ret;
+ }
+ }
+
+ phy_calibrate(usb2_generic_phy);
+ xhci_priv->priv = usb2_generic_phy;
+
+ xhci->quirks |= XHCI_RESET_ON_RESUME;
+
+ return 0;
+}
+
+int xhci_exynos_post_resume_quirk(struct usb_hcd *hcd)
+{
+ struct xhci_plat_priv *xhci_priv = hcd_to_xhci_priv(hcd);
+ struct phy *usb2_generic_phy = xhci_priv->priv;
+
+ phy_calibrate(usb2_generic_phy);
+
+ return 0;
+}
diff --git a/drivers/usb/host/xhci-exynos.h b/drivers/usb/host/xhci-exynos.h
new file mode 100644
index 000000000000..58ea3e9aea8d
--- /dev/null
+++ b/drivers/usb/host/xhci-exynos.h
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * drivers/usb/host/xhci-exynos.h
+ *
+ * Copyright (C) 2019 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef _XHCI_EXYNOS_H
+#define _XHCI_EXYNOS_H
+
+
+#if IS_ENABLED(CONFIG_USB_XHCI_EXYNOS)
+int xhci_exynos_init_quirk(struct usb_hcd *hcd);
+int xhci_exynos_post_resume_quirk(struct usb_hcd *hcd);
+#else
+static inline int xhci_exynos_init_quirk(struct usb_hcd *hcd)
+{
+ return 0;
+}
+
+static inline int xhci_exynos_post_resume_quirk(struct usb_hcd *hcd)
+{
+ return 0;
+}
+#endif
+#endif /* _XHCI_EXYNOS_H */
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 998241f5fce3..6bc03cdb2f21 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -24,6 +24,7 @@
#include "xhci-plat.h"
#include "xhci-mvebu.h"
#include "xhci-rcar.h"
+#include "xhci-exynos.h"
static struct hc_driver __read_mostly xhci_plat_hc_driver;
@@ -64,6 +65,16 @@ static int xhci_priv_resume_quirk(struct usb_hcd *hcd)
return priv->resume_quirk(hcd);
}
+static int xhci_priv_post_resume_quirk(struct usb_hcd *hcd)
+{
+ struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
+
+ if (!priv->post_resume_quirk)
+ return 0;
+
+ return priv->post_resume_quirk(hcd);
+}
+
static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
{
/*
@@ -102,6 +113,11 @@ static const struct xhci_plat_priv xhci_plat_marvell_armada3700 = {
.init_quirk = xhci_mvebu_a3700_init_quirk,
};
+static const struct xhci_plat_priv xhci_plat_samsung_exynos5 = {
+ .init_quirk = xhci_exynos_init_quirk,
+ .post_resume_quirk = xhci_exynos_post_resume_quirk,
+};
+
static const struct xhci_plat_priv xhci_plat_renesas_rcar_gen2 = {
.firmware_name = XHCI_RCAR_FIRMWARE_NAME_V1,
.init_quirk = xhci_rcar_init_quirk,
@@ -260,6 +276,13 @@ static int xhci_plat_probe(struct platform_device *pdev)
goto disable_reg_clk;
priv_match = of_device_get_match_data(&pdev->dev);
+ if (!priv_match) {
+ const struct platform_device_id *id =
+ platform_get_device_id(pdev);
+ if (id)
+ priv_match = (const struct xhci_plat_priv *)
+ id->driver_data;
+ }
if (priv_match) {
struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
@@ -413,7 +436,11 @@ static int __maybe_unused xhci_plat_resume(struct device *dev)
if (ret)
return ret;
- return xhci_resume(xhci, 0);
+ ret = xhci_resume(xhci, 0);
+ if (ret)
+ return ret;
+
+ return xhci_priv_post_resume_quirk(hcd);
}
static int __maybe_unused xhci_plat_runtime_suspend(struct device *dev)
@@ -447,9 +474,18 @@ static const struct acpi_device_id usb_xhci_acpi_match[] = {
};
MODULE_DEVICE_TABLE(acpi, usb_xhci_acpi_match);
+static struct platform_device_id xhci_plat_driver_ids[] = {
+ {
+ .name = "exynos5-dwc3-xhci",
+ .driver_data = (long) &xhci_plat_samsung_exynos5,
+ }, { },
+};
+MODULE_DEVICE_TABLE(platform, xhci_plat_driver_ids);
+
static struct platform_driver usb_xhci_driver = {
.probe = xhci_plat_probe,
.remove = xhci_plat_remove,
+ .id_table = xhci_plat_driver_ids,
.driver = {
.name = "xhci-hcd",
.pm = &xhci_plat_pm_ops,
diff --git a/drivers/usb/host/xhci-plat.h b/drivers/usb/host/xhci-plat.h
index ae29f22ff5bd..f8a8e84b4ebe 100644
--- a/drivers/usb/host/xhci-plat.h
+++ b/drivers/usb/host/xhci-plat.h
@@ -12,9 +12,11 @@
struct xhci_plat_priv {
const char *firmware_name;
+ void *priv;
void (*plat_start)(struct usb_hcd *);
int (*init_quirk)(struct usb_hcd *);
int (*resume_quirk)(struct usb_hcd *);
+ int (*post_resume_quirk)(struct usb_hcd *);
};
#define hcd_to_xhci_priv(h) ((struct xhci_plat_priv *)hcd_to_xhci(h)->priv)
--
2.17.1