Add support for the DWC3 USB controller found on Google Tensor G5
(codename: laguna). The controller features dual-role functionality
and hibernation.
The primary focus is implementing hibernation support in host mode,
enabling the controller to enter a low-power state (D3). This is
particularly relevant during system power state transition and
runtime power management for power efficiency.
Highlights:
- Align suspend callback with dwc3_suspend_common() for deciding
between a full teardown and hibernation in host mode.
- Integration with `psw` (power switchable) and `top` power domains,
managing their states and device links to support hibernation.
- A notifier callback dwc3_google_usb_psw_pd_notifier() for
`psw` power domain events to manage controller state
transitions to/from D3.
- Coordination of the `non_sticky` reset during power state
transitions, asserting it on D3 entry and deasserting on D0 entry
in hibernation scenario.
- Handling of high-speed and super-speed PME interrupts
that are generated by remote wakeup during hibernation.
Co-developed-by: Joy Chakraborty <joychakr@google.com>
Signed-off-by: Joy Chakraborty <joychakr@google.com>
Co-developed-by: Naveen Kumar <mnkumar@google.com>
Signed-off-by: Naveen Kumar <mnkumar@google.com>
Signed-off-by: Roy Luo <royluo@google.com>
---
drivers/usb/dwc3/Kconfig | 10 +
drivers/usb/dwc3/Makefile | 1 +
drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++
3 files changed, 639 insertions(+)
create mode 100644 drivers/usb/dwc3/dwc3-google.c
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 4925d15084f8..bb0e4dc97da3 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -200,4 +200,14 @@ config USB_DWC3_GENERIC_PLAT
the dwc3 child node in the device tree.
Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
+config USB_DWC3_GOOGLE
+ tristate "Google Platform"
+ depends on OF && COMMON_CLK && RESET_CONTROLLER
+ default n
+ help
+ Support the DesignWare Core USB3 IP found on Google Tensor
+ SoCs, starting with the G5 generation. This driver includes
+ support for hibernation in host mode.
+ Say 'Y' or 'M' if you have one such device.
+
endif
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index 96469e48ff9d..cf1cd408d938 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -58,3 +58,4 @@ obj-$(CONFIG_USB_DWC3_XILINX) += dwc3-xilinx.o
obj-$(CONFIG_USB_DWC3_OCTEON) += dwc3-octeon.o
obj-$(CONFIG_USB_DWC3_RTK) += dwc3-rtk.o
obj-$(CONFIG_USB_DWC3_GENERIC_PLAT) += dwc3-generic-plat.o
+obj-$(CONFIG_USB_DWC3_GOOGLE) += dwc3-google.o
diff --git a/drivers/usb/dwc3/dwc3-google.c b/drivers/usb/dwc3/dwc3-google.c
new file mode 100644
index 000000000000..428adf7d6049
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-google.c
@@ -0,0 +1,628 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dwc3-google.c - Google DWC3 Specific Glue Layer
+ *
+ * Copyright (c) 2025, Google LLC
+ * Author: Roy Luo <royluo@google.com>
+ */
+
+#include <linux/of.h>
+#include <linux/bitfield.h>
+#include <linux/irq.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/pm_domain.h>
+#include <linux/iopoll.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include "core.h"
+#include "glue.h"
+
+/* HOST CFG registers */
+#define HC_STATUS_OFFSET 0x0
+#define HC_STATUS_CURRENT_POWER_STATE_U2PMU GENMASK(1, 0)
+#define HC_STATUS_CURRENT_POWER_STATE_U3PMU GENMASK(4, 3)
+
+#define HOST_CFG1_OFFSET 0x4
+#define HOST_CFG1_PME_EN BIT(3)
+#define HOST_CFG1_PM_POWER_STATE_REQUEST GENMASK(5, 4)
+#define HOST_CFG1_PM_POWER_STATE_D0 0x0
+#define HOST_CFG1_PM_POWER_STATE_D3 0x3
+
+/* USBINT registers */
+#define USBINT_CFG1_OFFSET 0x0
+#define USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK BIT(2)
+#define USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK BIT(3)
+#define USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN BIT(8)
+#define USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN BIT(9)
+#define USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR BIT(14)
+#define USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR BIT(15)
+
+#define USBINT_STATUS_OFFSET 0x4
+#define USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW BIT(2)
+#define USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW BIT(3)
+
+#define USBCS_TOP_CTRL_CFG1_OFFSET 0xc
+#define USBCS_TOP_CTRL_CFG1_USB2ONLY_MODE BIT(5)
+
+#define DWC3_GOOGLE_MAX_RESETS 4
+
+struct dwc3_google {
+ struct device *dev;
+ struct dwc3 dwc;
+ struct clk_bulk_data *clks;
+ int num_clks;
+ struct reset_control_bulk_data rsts[DWC3_GOOGLE_MAX_RESETS];
+ int num_rsts;
+ struct reset_control *non_sticky_rst;
+ struct device *usb_psw_pd;
+ struct device_link *usb_psw_pd_dl;
+ struct notifier_block usb_psw_pd_nb;
+ struct device *usb_top_pd;
+ struct device_link *usb_top_pd_dl;
+ struct regmap *usb_cfg_regmap;
+ unsigned int host_cfg_offset;
+ unsigned int usbint_cfg_offset;
+ int hs_pme_irq;
+ int ss_pme_irq;
+ bool is_usb2only;
+ bool is_hibernation;
+};
+
+#define to_dwc3_google(d) container_of((d), struct dwc3_google, dwc)
+
+static int dwc3_google_rst_init(struct dwc3_google *google)
+{
+ int ret;
+
+ google->num_rsts = 4;
+ google->rsts[0].id = "non_sticky";
+ google->rsts[1].id = "sticky";
+ google->rsts[2].id = "drd_bus";
+ google->rsts[3].id = "top";
+
+ ret = devm_reset_control_bulk_get_exclusive(google->dev,
+ google->num_rsts,
+ google->rsts);
+
+ if (ret < 0)
+ return ret;
+
+ google->non_sticky_rst = google->rsts[0].rstc;
+
+ return 0;
+}
+
+static int dwc3_google_set_pmu_state(struct dwc3_google *google, int state)
+{
+ u32 reg;
+ int ret;
+
+ regmap_read(google->usb_cfg_regmap,
+ google->host_cfg_offset + HOST_CFG1_OFFSET, ®);
+
+ reg &= ~HOST_CFG1_PM_POWER_STATE_REQUEST;
+ reg |= (FIELD_PREP(HOST_CFG1_PM_POWER_STATE_REQUEST, state) |
+ HOST_CFG1_PME_EN);
+ regmap_write(google->usb_cfg_regmap,
+ google->host_cfg_offset + HOST_CFG1_OFFSET, reg);
+
+ ret = regmap_read_poll_timeout(google->usb_cfg_regmap,
+ google->host_cfg_offset + HC_STATUS_OFFSET, reg,
+ (FIELD_GET(HC_STATUS_CURRENT_POWER_STATE_U2PMU,
+ reg) == state &&
+ FIELD_GET(HC_STATUS_CURRENT_POWER_STATE_U3PMU,
+ reg) == state),
+ 10, 10000);
+
+ if (ret)
+ dev_err(google->dev, "failed to set PMU state %d\n", state);
+
+ return ret;
+}
+
+/*
+ * Clear pme interrupts and report their status.
+ * The hardware requires write-1 then write-0 sequence to clear the interrupt bits.
+ */
+static u32 dwc3_google_clear_pme_irqs(struct dwc3_google *google)
+{
+ u32 irq_status, reg_set, reg_clear;
+
+ regmap_read(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBINT_STATUS_OFFSET, &irq_status);
+
+ irq_status &= (USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW |
+ USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW);
+ if (!irq_status)
+ return irq_status;
+
+ regmap_read(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®_set);
+
+ reg_clear = reg_set;
+ if (irq_status & USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW) {
+ reg_set |= USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR;
+ reg_clear &= ~USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR;
+ }
+ if (irq_status & USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW) {
+ reg_set |= USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR;
+ reg_clear &= ~USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR;
+ }
+
+ regmap_write(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg_set);
+ regmap_write(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg_clear);
+
+ return irq_status;
+}
+
+static void dwc3_google_enable_pme_irq(struct dwc3_google *google)
+{
+ u32 reg;
+
+ regmap_read(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®);
+ reg &= ~(USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK |
+ USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK);
+ reg |= (USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN |
+ USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN);
+ regmap_write(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg);
+
+ enable_irq(google->hs_pme_irq);
+ enable_irq(google->ss_pme_irq);
+ enable_irq_wake(google->hs_pme_irq);
+ enable_irq_wake(google->ss_pme_irq);
+}
+
+static void dwc3_google_disable_pme_irq(struct dwc3_google *google)
+{
+ u32 reg;
+
+ regmap_read(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®);
+ reg &= ~(USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN |
+ USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN);
+ reg |= (USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK |
+ USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK);
+ regmap_write(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg);
+
+ disable_irq_wake(google->hs_pme_irq);
+ disable_irq_wake(google->ss_pme_irq);
+ disable_irq_nosync(google->hs_pme_irq);
+ disable_irq_nosync(google->ss_pme_irq);
+}
+
+static irqreturn_t dwc3_google_resume_irq(int irq, void *data)
+{
+ struct dwc3_google *google = data;
+ struct dwc3 *dwc = &google->dwc;
+ u32 irq_status, dr_role;
+
+ irq_status = dwc3_google_clear_pme_irqs(google);
+ dr_role = dwc->current_dr_role;
+
+ if (!irq_status || !google->is_hibernation ||
+ dr_role != DWC3_GCTL_PRTCAP_HOST) {
+ dev_dbg(google->dev, "spurious pme irq %d, hibernation %d, dr_role %u\n",
+ irq, google->is_hibernation, dr_role);
+ return IRQ_HANDLED;
+ }
+
+ if (dwc->xhci)
+ pm_runtime_resume(&dwc->xhci->dev);
+
+ return IRQ_HANDLED;
+}
+
+static int dwc3_google_request_irq(struct dwc3_google *google, struct platform_device *pdev,
+ const char *irq_name, const char *req_name)
+{
+ int ret;
+ int irq;
+
+ irq = platform_get_irq_byname(pdev, irq_name);
+ if (irq < 0) {
+ dev_err(google->dev, "invalid irq name %s\n", irq_name);
+ return irq;
+ }
+
+ irq_set_status_flags(irq, IRQ_NOAUTOEN);
+ ret = devm_request_threaded_irq(google->dev, irq, NULL,
+ dwc3_google_resume_irq,
+ IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+ req_name, google);
+ if (ret < 0) {
+ dev_err(google->dev, "failed to request irq %s\n", req_name);
+ return ret;
+ }
+
+ return irq;
+}
+
+static int dwc3_google_usb_psw_pd_notifier(struct notifier_block *nb, unsigned long action, void *d)
+{
+ struct dwc3_google *google = container_of(nb, struct dwc3_google, usb_psw_pd_nb);
+ int ret;
+
+ if (!google->is_hibernation)
+ return NOTIFY_OK;
+
+ if (action == GENPD_NOTIFY_OFF) {
+ dev_dbg(google->dev, "enter D3 power state\n");
+ dwc3_google_set_pmu_state(google, HOST_CFG1_PM_POWER_STATE_D3);
+ ret = reset_control_assert(google->non_sticky_rst);
+ if (ret)
+ dev_err(google->dev, "non sticky reset assert failed: %d\n", ret);
+ } else if (action == GENPD_NOTIFY_ON) {
+ dev_dbg(google->dev, "enter D0 power state\n");
+ dwc3_google_clear_pme_irqs(google);
+ ret = reset_control_deassert(google->non_sticky_rst);
+ if (ret)
+ dev_err(google->dev, "non sticky reset deassert failed: %d\n", ret);
+ dwc3_google_set_pmu_state(google, HOST_CFG1_PM_POWER_STATE_D0);
+ }
+
+ return NOTIFY_OK;
+}
+
+static void dwc3_google_pm_domain_deinit(struct dwc3_google *google)
+{
+ if (google->usb_top_pd_dl)
+ device_link_del(google->usb_top_pd_dl);
+
+ if (!IS_ERR_OR_NULL(google->usb_top_pd)) {
+ device_set_wakeup_capable(google->usb_top_pd, false);
+ dev_pm_domain_detach(google->usb_top_pd, true);
+ }
+
+ if (google->usb_psw_pd_dl)
+ device_link_del(google->usb_psw_pd_dl);
+
+ if (!IS_ERR_OR_NULL(google->usb_psw_pd)) {
+ dev_pm_genpd_remove_notifier(google->usb_psw_pd);
+ dev_pm_domain_detach(google->usb_psw_pd, true);
+ }
+}
+
+static int dwc3_google_pm_domain_init(struct dwc3_google *google)
+{
+ int ret;
+
+ /*
+ * Establish PM RUNTIME link between dwc dev and its power domain usb_psw_pd,
+ * register notifier block to handle hibernation.
+ */
+ google->usb_psw_pd = dev_pm_domain_attach_by_name(google->dev, "psw");
+ if (IS_ERR_OR_NULL(google->usb_psw_pd)) {
+ dev_err(google->dev, "failed to get psw pd");
+ ret = google->usb_psw_pd ? PTR_ERR(google->usb_psw_pd) : -ENODATA;
+ return ret;
+ }
+
+ google->usb_psw_pd_nb.notifier_call = dwc3_google_usb_psw_pd_notifier;
+ ret = dev_pm_genpd_add_notifier(google->usb_psw_pd, &google->usb_psw_pd_nb);
+ if (ret) {
+ dev_err(google->dev, "failed to add psw pd notifier");
+ goto err;
+ }
+
+ google->usb_psw_pd_dl = device_link_add(google->dev, google->usb_psw_pd,
+ DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
+ DL_FLAG_RPM_ACTIVE);
+ if (!google->usb_psw_pd_dl) {
+ dev_err(google->usb_psw_pd, "failed to add device link");
+ ret = -ENODEV;
+ goto err;
+ }
+
+ /*
+ * usb_top_pd is the parent power domain of usb_psw_pd. Keeping usb_top_pd on
+ * while usb_psw_pd is off places the controller in a power-gated state,
+ * essential for hibernation. Acquire a handle to usb_top_pd and sets it as
+ * wakeup-capable to allow the domain to be left on during system suspend.
+ */
+ google->usb_top_pd = dev_pm_domain_attach_by_name(google->dev, "top");
+ if (IS_ERR_OR_NULL(google->usb_top_pd)) {
+ dev_err(google->dev, "failed to get top pd");
+ ret = google->usb_top_pd ? PTR_ERR(google->usb_top_pd) : -ENODATA;
+ goto err;
+ }
+ device_set_wakeup_capable(google->usb_top_pd, true);
+
+ google->usb_top_pd_dl = device_link_add(google->dev, google->usb_top_pd,
+ DL_FLAG_STATELESS);
+ if (!google->usb_top_pd_dl) {
+ dev_err(google->usb_top_pd, "failed to add device link");
+ ret = -ENODEV;
+ goto err;
+ }
+
+ return 0;
+
+err:
+ dwc3_google_pm_domain_deinit(google);
+
+ return ret;
+}
+
+static void dwc3_google_program_usb2only(struct dwc3_google *google)
+{
+ u32 reg;
+
+ regmap_read(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBCS_TOP_CTRL_CFG1_OFFSET, ®);
+ reg |= USBCS_TOP_CTRL_CFG1_USB2ONLY_MODE;
+ regmap_write(google->usb_cfg_regmap,
+ google->usbint_cfg_offset + USBCS_TOP_CTRL_CFG1_OFFSET, reg);
+}
+
+static int dwc3_google_probe(struct platform_device *pdev)
+{
+ struct dwc3_probe_data probe_data = {};
+ struct device *dev = &pdev->dev;
+ struct dwc3_google *google;
+ struct resource *res;
+ int ret;
+ u32 args[2];
+
+ google = devm_kzalloc(&pdev->dev, sizeof(*google), GFP_KERNEL);
+ if (!google)
+ return -ENOMEM;
+
+ google->dev = &pdev->dev;
+
+ ret = dwc3_google_pm_domain_init(google);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to init pdom\n");
+
+ google->usb_cfg_regmap =
+ syscon_regmap_lookup_by_phandle_args(dev->of_node,
+ "google,usb-cfg-csr",
+ ARRAY_SIZE(args), args);
+ if (IS_ERR(google->usb_cfg_regmap)) {
+ return dev_err_probe(dev, PTR_ERR(google->usb_cfg_regmap),
+ "invalid usb cfg csr\n");
+ }
+
+ google->host_cfg_offset = args[0];
+ google->usbint_cfg_offset = args[1];
+
+ if (device_property_match_string(dev, "phy-names", "usb3-phy") < 0) {
+ google->is_usb2only = true;
+ dwc3_google_program_usb2only(google);
+ }
+
+ ret = devm_clk_bulk_get_all_enabled(dev, &google->clks);
+ if (ret < 0) {
+ ret = dev_err_probe(dev, ret, "failed to get and enable clks\n");
+ goto err_deinit_pdom;
+ }
+ google->num_clks = ret;
+
+ ret = dwc3_google_rst_init(google);
+ if (ret) {
+ ret = dev_err_probe(dev, ret, "failed to get resets\n");
+ goto err_deinit_pdom;
+ }
+
+ ret = reset_control_bulk_deassert(google->num_rsts, google->rsts);
+ if (ret) {
+ ret = dev_err_probe(dev, ret, "failed to deassert rsts\n");
+ goto err_deinit_pdom;
+ }
+
+ ret = dwc3_google_request_irq(google, pdev, "hs_pme", "USB HS wakeup");
+ if (ret < 0) {
+ ret = dev_err_probe(dev, ret, "failed to request hs pme irq");
+ goto err_reset_assert;
+ }
+ google->hs_pme_irq = ret;
+
+ ret = dwc3_google_request_irq(google, pdev, "ss_pme", "USB SS wakeup");
+ if (ret < 0) {
+ ret = dev_err_probe(dev, ret, "failed to request ss pme irq");
+ goto err_reset_assert;
+ }
+ google->ss_pme_irq = ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ ret = dev_err_probe(dev, -ENODEV, "invalid memory\n");
+ goto err_reset_assert;
+ }
+
+ device_init_wakeup(dev, true);
+
+ google->dwc.dev = dev;
+ probe_data.dwc = &google->dwc;
+ probe_data.res = res;
+ probe_data.ignore_clocks_and_resets = true;
+ ret = dwc3_core_probe(&probe_data);
+ if (ret) {
+ ret = dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
+ goto err_reset_assert;
+ }
+
+ return 0;
+
+err_reset_assert:
+ reset_control_bulk_assert(google->num_rsts, google->rsts);
+
+err_deinit_pdom:
+ dwc3_google_pm_domain_deinit(google);
+
+ return ret;
+}
+
+static void dwc3_google_remove(struct platform_device *pdev)
+{
+ struct dwc3 *dwc = platform_get_drvdata(pdev);
+ struct dwc3_google *google = to_dwc3_google(dwc);
+
+ dwc3_core_remove(&google->dwc);
+
+ reset_control_bulk_assert(google->num_rsts, google->rsts);
+
+ dwc3_google_pm_domain_deinit(google);
+}
+
+static int dwc3_google_suspend(struct dwc3_google *google, pm_message_t msg)
+{
+ if (pm_runtime_suspended(google->dev))
+ return 0;
+
+ if (google->dwc.current_dr_role == DWC3_GCTL_PRTCAP_HOST) {
+ /*
+ * Follow dwc3_suspend_common() guidelines for deciding between
+ * a full teardown and hibernation.
+ */
+ if (PMSG_IS_AUTO(msg) || device_may_wakeup(google->dev)) {
+ dev_dbg(google->dev, "enter hibernation");
+ pm_runtime_get_sync(google->usb_top_pd);
+ device_wakeup_enable(google->usb_top_pd);
+ dwc3_google_enable_pme_irq(google);
+ google->is_hibernation = true;
+ return 0;
+ }
+ }
+
+ reset_control_bulk_assert(google->num_rsts, google->rsts);
+ clk_bulk_disable_unprepare(google->num_clks, google->clks);
+
+ return 0;
+}
+
+static int dwc3_google_resume(struct dwc3_google *google, pm_message_t msg)
+{
+ int ret;
+
+ if (google->is_hibernation) {
+ dev_dbg(google->dev, "exit hibernation");
+ dwc3_google_disable_pme_irq(google);
+ device_wakeup_disable(google->usb_top_pd);
+ pm_runtime_put_sync(google->usb_top_pd);
+ google->is_hibernation = false;
+ return 0;
+ }
+
+ if (google->is_usb2only)
+ dwc3_google_program_usb2only(google);
+
+ ret = clk_bulk_prepare_enable(google->num_clks, google->clks);
+ if (ret)
+ return ret;
+
+ ret = reset_control_bulk_deassert(google->num_rsts, google->rsts);
+ if (ret) {
+ clk_bulk_disable_unprepare(google->num_clks, google->clks);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int dwc3_google_pm_suspend(struct device *dev)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+ struct dwc3_google *google = to_dwc3_google(dwc);
+ int ret;
+
+ ret = dwc3_pm_suspend(&google->dwc);
+ if (ret)
+ return ret;
+
+ return dwc3_google_suspend(google, PMSG_SUSPEND);
+}
+
+static int dwc3_google_pm_resume(struct device *dev)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+ struct dwc3_google *google = to_dwc3_google(dwc);
+ int ret;
+
+ ret = dwc3_google_resume(google, PMSG_RESUME);
+ if (ret)
+ return ret;
+
+ return dwc3_pm_resume(&google->dwc);
+}
+
+static void dwc3_google_complete(struct device *dev)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+
+ dwc3_pm_complete(dwc);
+}
+
+static int dwc3_google_prepare(struct device *dev)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+
+ return dwc3_pm_prepare(dwc);
+}
+
+static int dwc3_google_runtime_suspend(struct device *dev)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+ struct dwc3_google *google = to_dwc3_google(dwc);
+ int ret;
+
+ ret = dwc3_runtime_suspend(&google->dwc);
+ if (ret)
+ return ret;
+
+ return dwc3_google_suspend(google, PMSG_AUTO_SUSPEND);
+}
+
+static int dwc3_google_runtime_resume(struct device *dev)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+ struct dwc3_google *google = to_dwc3_google(dwc);
+ int ret;
+
+ ret = dwc3_google_resume(google, PMSG_AUTO_RESUME);
+ if (ret)
+ return ret;
+
+ return dwc3_runtime_resume(&google->dwc);
+}
+
+static int dwc3_google_runtime_idle(struct device *dev)
+{
+ return dwc3_runtime_idle(dev_get_drvdata(dev));
+}
+
+static const struct dev_pm_ops dwc3_google_dev_pm_ops = {
+ SYSTEM_SLEEP_PM_OPS(dwc3_google_pm_suspend, dwc3_google_pm_resume)
+ RUNTIME_PM_OPS(dwc3_google_runtime_suspend, dwc3_google_runtime_resume,
+ dwc3_google_runtime_idle)
+ .complete = pm_sleep_ptr(dwc3_google_complete),
+ .prepare = pm_sleep_ptr(dwc3_google_prepare),
+};
+
+static const struct of_device_id dwc3_google_of_match[] = {
+ { .compatible = "google,lga-dwc3" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, dwc3_google_of_match);
+
+static struct platform_driver dwc3_google_driver = {
+ .probe = dwc3_google_probe,
+ .remove = dwc3_google_remove,
+ .driver = {
+ .name = "google-dwc3",
+ .pm = pm_ptr(&dwc3_google_dev_pm_ops),
+ .of_match_table = dwc3_google_of_match,
+ },
+};
+
+module_platform_driver(dwc3_google_driver);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("DesignWare DWC3 Google Glue Driver");
--
2.51.2.1041.gc1ab5b90ca-googOn Wed, Nov 12, 2025, Roy Luo wrote:
> Add support for the DWC3 USB controller found on Google Tensor G5
> (codename: laguna). The controller features dual-role functionality
> and hibernation.
>
> The primary focus is implementing hibernation support in host mode,
> enabling the controller to enter a low-power state (D3). This is
> particularly relevant during system power state transition and
> runtime power management for power efficiency.
> Highlights:
> - Align suspend callback with dwc3_suspend_common() for deciding
> between a full teardown and hibernation in host mode.
> - Integration with `psw` (power switchable) and `top` power domains,
> managing their states and device links to support hibernation.
> - A notifier callback dwc3_google_usb_psw_pd_notifier() for
> `psw` power domain events to manage controller state
> transitions to/from D3.
> - Coordination of the `non_sticky` reset during power state
> transitions, asserting it on D3 entry and deasserting on D0 entry
> in hibernation scenario.
> - Handling of high-speed and super-speed PME interrupts
> that are generated by remote wakeup during hibernation.
>
> Co-developed-by: Joy Chakraborty <joychakr@google.com>
> Signed-off-by: Joy Chakraborty <joychakr@google.com>
> Co-developed-by: Naveen Kumar <mnkumar@google.com>
> Signed-off-by: Naveen Kumar <mnkumar@google.com>
> Signed-off-by: Roy Luo <royluo@google.com>
> ---
> drivers/usb/dwc3/Kconfig | 10 +
> drivers/usb/dwc3/Makefile | 1 +
> drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++
> 3 files changed, 639 insertions(+)
> create mode 100644 drivers/usb/dwc3/dwc3-google.c
>
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 4925d15084f8..bb0e4dc97da3 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -200,4 +200,14 @@ config USB_DWC3_GENERIC_PLAT
> the dwc3 child node in the device tree.
> Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
>
> +config USB_DWC3_GOOGLE
> + tristate "Google Platform"
> + depends on OF && COMMON_CLK && RESET_CONTROLLER
> + default n
> + help
> + Support the DesignWare Core USB3 IP found on Google Tensor
> + SoCs, starting with the G5 generation. This driver includes
> + support for hibernation in host mode.
> + Say 'Y' or 'M' if you have one such device.
> +
> endif
> diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> index 96469e48ff9d..cf1cd408d938 100644
> --- a/drivers/usb/dwc3/Makefile
> +++ b/drivers/usb/dwc3/Makefile
> @@ -58,3 +58,4 @@ obj-$(CONFIG_USB_DWC3_XILINX) += dwc3-xilinx.o
> obj-$(CONFIG_USB_DWC3_OCTEON) += dwc3-octeon.o
> obj-$(CONFIG_USB_DWC3_RTK) += dwc3-rtk.o
> obj-$(CONFIG_USB_DWC3_GENERIC_PLAT) += dwc3-generic-plat.o
> +obj-$(CONFIG_USB_DWC3_GOOGLE) += dwc3-google.o
> diff --git a/drivers/usb/dwc3/dwc3-google.c b/drivers/usb/dwc3/dwc3-google.c
> new file mode 100644
> index 000000000000..428adf7d6049
> --- /dev/null
> +++ b/drivers/usb/dwc3/dwc3-google.c
> @@ -0,0 +1,628 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * dwc3-google.c - Google DWC3 Specific Glue Layer
> + *
> + * Copyright (c) 2025, Google LLC
> + * Author: Roy Luo <royluo@google.com>
> + */
> +
> +#include <linux/of.h>
> +#include <linux/bitfield.h>
> +#include <linux/irq.h>
> +#include <linux/clk.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/pm_domain.h>
> +#include <linux/iopoll.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +#include "core.h"
> +#include "glue.h"
> +
> +/* HOST CFG registers */
> +#define HC_STATUS_OFFSET 0x0
> +#define HC_STATUS_CURRENT_POWER_STATE_U2PMU GENMASK(1, 0)
> +#define HC_STATUS_CURRENT_POWER_STATE_U3PMU GENMASK(4, 3)
> +
> +#define HOST_CFG1_OFFSET 0x4
> +#define HOST_CFG1_PME_EN BIT(3)
> +#define HOST_CFG1_PM_POWER_STATE_REQUEST GENMASK(5, 4)
> +#define HOST_CFG1_PM_POWER_STATE_D0 0x0
> +#define HOST_CFG1_PM_POWER_STATE_D3 0x3
> +
> +/* USBINT registers */
> +#define USBINT_CFG1_OFFSET 0x0
> +#define USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK BIT(2)
> +#define USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK BIT(3)
> +#define USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN BIT(8)
> +#define USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN BIT(9)
> +#define USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR BIT(14)
> +#define USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR BIT(15)
> +
> +#define USBINT_STATUS_OFFSET 0x4
> +#define USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW BIT(2)
> +#define USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW BIT(3)
> +
> +#define USBCS_TOP_CTRL_CFG1_OFFSET 0xc
> +#define USBCS_TOP_CTRL_CFG1_USB2ONLY_MODE BIT(5)
> +
> +#define DWC3_GOOGLE_MAX_RESETS 4
> +
> +struct dwc3_google {
> + struct device *dev;
> + struct dwc3 dwc;
> + struct clk_bulk_data *clks;
> + int num_clks;
> + struct reset_control_bulk_data rsts[DWC3_GOOGLE_MAX_RESETS];
> + int num_rsts;
> + struct reset_control *non_sticky_rst;
> + struct device *usb_psw_pd;
> + struct device_link *usb_psw_pd_dl;
> + struct notifier_block usb_psw_pd_nb;
> + struct device *usb_top_pd;
> + struct device_link *usb_top_pd_dl;
> + struct regmap *usb_cfg_regmap;
> + unsigned int host_cfg_offset;
> + unsigned int usbint_cfg_offset;
> + int hs_pme_irq;
> + int ss_pme_irq;
> + bool is_usb2only;
> + bool is_hibernation;
> +};
> +
> +#define to_dwc3_google(d) container_of((d), struct dwc3_google, dwc)
> +
> +static int dwc3_google_rst_init(struct dwc3_google *google)
> +{
> + int ret;
> +
> + google->num_rsts = 4;
> + google->rsts[0].id = "non_sticky";
> + google->rsts[1].id = "sticky";
> + google->rsts[2].id = "drd_bus";
> + google->rsts[3].id = "top";
> +
> + ret = devm_reset_control_bulk_get_exclusive(google->dev,
> + google->num_rsts,
> + google->rsts);
> +
> + if (ret < 0)
> + return ret;
> +
> + google->non_sticky_rst = google->rsts[0].rstc;
> +
> + return 0;
> +}
> +
> +static int dwc3_google_set_pmu_state(struct dwc3_google *google, int state)
> +{
> + u32 reg;
> + int ret;
> +
> + regmap_read(google->usb_cfg_regmap,
> + google->host_cfg_offset + HOST_CFG1_OFFSET, ®);
> +
> + reg &= ~HOST_CFG1_PM_POWER_STATE_REQUEST;
> + reg |= (FIELD_PREP(HOST_CFG1_PM_POWER_STATE_REQUEST, state) |
> + HOST_CFG1_PME_EN);
> + regmap_write(google->usb_cfg_regmap,
> + google->host_cfg_offset + HOST_CFG1_OFFSET, reg);
> +
> + ret = regmap_read_poll_timeout(google->usb_cfg_regmap,
> + google->host_cfg_offset + HC_STATUS_OFFSET, reg,
> + (FIELD_GET(HC_STATUS_CURRENT_POWER_STATE_U2PMU,
> + reg) == state &&
> + FIELD_GET(HC_STATUS_CURRENT_POWER_STATE_U3PMU,
> + reg) == state),
> + 10, 10000);
> +
> + if (ret)
> + dev_err(google->dev, "failed to set PMU state %d\n", state);
> +
> + return ret;
> +}
> +
> +/*
> + * Clear pme interrupts and report their status.
> + * The hardware requires write-1 then write-0 sequence to clear the interrupt bits.
> + */
> +static u32 dwc3_google_clear_pme_irqs(struct dwc3_google *google)
> +{
> + u32 irq_status, reg_set, reg_clear;
> +
> + regmap_read(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBINT_STATUS_OFFSET, &irq_status);
> +
> + irq_status &= (USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW |
> + USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW);
> + if (!irq_status)
> + return irq_status;
> +
> + regmap_read(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®_set);
> +
> + reg_clear = reg_set;
> + if (irq_status & USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW) {
> + reg_set |= USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR;
> + reg_clear &= ~USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR;
> + }
> + if (irq_status & USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW) {
> + reg_set |= USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR;
> + reg_clear &= ~USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR;
> + }
> +
> + regmap_write(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg_set);
> + regmap_write(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg_clear);
> +
> + return irq_status;
> +}
> +
> +static void dwc3_google_enable_pme_irq(struct dwc3_google *google)
> +{
> + u32 reg;
> +
> + regmap_read(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®);
> + reg &= ~(USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK |
> + USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK);
> + reg |= (USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN |
> + USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN);
> + regmap_write(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg);
> +
> + enable_irq(google->hs_pme_irq);
> + enable_irq(google->ss_pme_irq);
> + enable_irq_wake(google->hs_pme_irq);
> + enable_irq_wake(google->ss_pme_irq);
> +}
> +
> +static void dwc3_google_disable_pme_irq(struct dwc3_google *google)
> +{
> + u32 reg;
> +
> + regmap_read(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®);
> + reg &= ~(USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN |
> + USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN);
> + reg |= (USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK |
> + USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK);
> + regmap_write(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg);
> +
> + disable_irq_wake(google->hs_pme_irq);
> + disable_irq_wake(google->ss_pme_irq);
> + disable_irq_nosync(google->hs_pme_irq);
> + disable_irq_nosync(google->ss_pme_irq);
> +}
> +
> +static irqreturn_t dwc3_google_resume_irq(int irq, void *data)
> +{
> + struct dwc3_google *google = data;
> + struct dwc3 *dwc = &google->dwc;
> + u32 irq_status, dr_role;
> +
> + irq_status = dwc3_google_clear_pme_irqs(google);
> + dr_role = dwc->current_dr_role;
> +
> + if (!irq_status || !google->is_hibernation ||
> + dr_role != DWC3_GCTL_PRTCAP_HOST) {
> + dev_dbg(google->dev, "spurious pme irq %d, hibernation %d, dr_role %u\n",
> + irq, google->is_hibernation, dr_role);
> + return IRQ_HANDLED;
> + }
> +
> + if (dwc->xhci)
> + pm_runtime_resume(&dwc->xhci->dev);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int dwc3_google_request_irq(struct dwc3_google *google, struct platform_device *pdev,
> + const char *irq_name, const char *req_name)
> +{
> + int ret;
> + int irq;
> +
> + irq = platform_get_irq_byname(pdev, irq_name);
> + if (irq < 0) {
> + dev_err(google->dev, "invalid irq name %s\n", irq_name);
> + return irq;
> + }
> +
> + irq_set_status_flags(irq, IRQ_NOAUTOEN);
> + ret = devm_request_threaded_irq(google->dev, irq, NULL,
> + dwc3_google_resume_irq,
> + IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> + req_name, google);
> + if (ret < 0) {
> + dev_err(google->dev, "failed to request irq %s\n", req_name);
> + return ret;
> + }
> +
> + return irq;
> +}
> +
> +static int dwc3_google_usb_psw_pd_notifier(struct notifier_block *nb, unsigned long action, void *d)
> +{
> + struct dwc3_google *google = container_of(nb, struct dwc3_google, usb_psw_pd_nb);
> + int ret;
> +
> + if (!google->is_hibernation)
> + return NOTIFY_OK;
> +
> + if (action == GENPD_NOTIFY_OFF) {
> + dev_dbg(google->dev, "enter D3 power state\n");
> + dwc3_google_set_pmu_state(google, HOST_CFG1_PM_POWER_STATE_D3);
> + ret = reset_control_assert(google->non_sticky_rst);
> + if (ret)
> + dev_err(google->dev, "non sticky reset assert failed: %d\n", ret);
> + } else if (action == GENPD_NOTIFY_ON) {
> + dev_dbg(google->dev, "enter D0 power state\n");
> + dwc3_google_clear_pme_irqs(google);
> + ret = reset_control_deassert(google->non_sticky_rst);
> + if (ret)
> + dev_err(google->dev, "non sticky reset deassert failed: %d\n", ret);
> + dwc3_google_set_pmu_state(google, HOST_CFG1_PM_POWER_STATE_D0);
> + }
> +
> + return NOTIFY_OK;
> +}
> +
> +static void dwc3_google_pm_domain_deinit(struct dwc3_google *google)
> +{
> + if (google->usb_top_pd_dl)
> + device_link_del(google->usb_top_pd_dl);
> +
> + if (!IS_ERR_OR_NULL(google->usb_top_pd)) {
> + device_set_wakeup_capable(google->usb_top_pd, false);
> + dev_pm_domain_detach(google->usb_top_pd, true);
> + }
> +
> + if (google->usb_psw_pd_dl)
> + device_link_del(google->usb_psw_pd_dl);
> +
> + if (!IS_ERR_OR_NULL(google->usb_psw_pd)) {
> + dev_pm_genpd_remove_notifier(google->usb_psw_pd);
> + dev_pm_domain_detach(google->usb_psw_pd, true);
> + }
> +}
> +
> +static int dwc3_google_pm_domain_init(struct dwc3_google *google)
> +{
> + int ret;
> +
> + /*
> + * Establish PM RUNTIME link between dwc dev and its power domain usb_psw_pd,
> + * register notifier block to handle hibernation.
> + */
> + google->usb_psw_pd = dev_pm_domain_attach_by_name(google->dev, "psw");
> + if (IS_ERR_OR_NULL(google->usb_psw_pd)) {
> + dev_err(google->dev, "failed to get psw pd");
> + ret = google->usb_psw_pd ? PTR_ERR(google->usb_psw_pd) : -ENODATA;
> + return ret;
> + }
> +
> + google->usb_psw_pd_nb.notifier_call = dwc3_google_usb_psw_pd_notifier;
> + ret = dev_pm_genpd_add_notifier(google->usb_psw_pd, &google->usb_psw_pd_nb);
> + if (ret) {
> + dev_err(google->dev, "failed to add psw pd notifier");
> + goto err;
> + }
> +
> + google->usb_psw_pd_dl = device_link_add(google->dev, google->usb_psw_pd,
> + DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
> + DL_FLAG_RPM_ACTIVE);
> + if (!google->usb_psw_pd_dl) {
> + dev_err(google->usb_psw_pd, "failed to add device link");
> + ret = -ENODEV;
> + goto err;
> + }
> +
> + /*
> + * usb_top_pd is the parent power domain of usb_psw_pd. Keeping usb_top_pd on
> + * while usb_psw_pd is off places the controller in a power-gated state,
> + * essential for hibernation. Acquire a handle to usb_top_pd and sets it as
> + * wakeup-capable to allow the domain to be left on during system suspend.
> + */
> + google->usb_top_pd = dev_pm_domain_attach_by_name(google->dev, "top");
> + if (IS_ERR_OR_NULL(google->usb_top_pd)) {
> + dev_err(google->dev, "failed to get top pd");
> + ret = google->usb_top_pd ? PTR_ERR(google->usb_top_pd) : -ENODATA;
> + goto err;
> + }
> + device_set_wakeup_capable(google->usb_top_pd, true);
> +
> + google->usb_top_pd_dl = device_link_add(google->dev, google->usb_top_pd,
> + DL_FLAG_STATELESS);
> + if (!google->usb_top_pd_dl) {
> + dev_err(google->usb_top_pd, "failed to add device link");
> + ret = -ENODEV;
> + goto err;
> + }
> +
> + return 0;
> +
> +err:
> + dwc3_google_pm_domain_deinit(google);
> +
> + return ret;
> +}
> +
> +static void dwc3_google_program_usb2only(struct dwc3_google *google)
> +{
> + u32 reg;
> +
> + regmap_read(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBCS_TOP_CTRL_CFG1_OFFSET, ®);
> + reg |= USBCS_TOP_CTRL_CFG1_USB2ONLY_MODE;
> + regmap_write(google->usb_cfg_regmap,
> + google->usbint_cfg_offset + USBCS_TOP_CTRL_CFG1_OFFSET, reg);
> +}
> +
> +static int dwc3_google_probe(struct platform_device *pdev)
> +{
> + struct dwc3_probe_data probe_data = {};
> + struct device *dev = &pdev->dev;
> + struct dwc3_google *google;
> + struct resource *res;
> + int ret;
> + u32 args[2];
> +
> + google = devm_kzalloc(&pdev->dev, sizeof(*google), GFP_KERNEL);
> + if (!google)
> + return -ENOMEM;
> +
> + google->dev = &pdev->dev;
> +
> + ret = dwc3_google_pm_domain_init(google);
> + if (ret < 0)
> + return dev_err_probe(dev, ret, "failed to init pdom\n");
> +
> + google->usb_cfg_regmap =
> + syscon_regmap_lookup_by_phandle_args(dev->of_node,
> + "google,usb-cfg-csr",
> + ARRAY_SIZE(args), args);
> + if (IS_ERR(google->usb_cfg_regmap)) {
> + return dev_err_probe(dev, PTR_ERR(google->usb_cfg_regmap),
> + "invalid usb cfg csr\n");
> + }
> +
> + google->host_cfg_offset = args[0];
> + google->usbint_cfg_offset = args[1];
> +
> + if (device_property_match_string(dev, "phy-names", "usb3-phy") < 0) {
> + google->is_usb2only = true;
> + dwc3_google_program_usb2only(google);
> + }
> +
> + ret = devm_clk_bulk_get_all_enabled(dev, &google->clks);
> + if (ret < 0) {
> + ret = dev_err_probe(dev, ret, "failed to get and enable clks\n");
> + goto err_deinit_pdom;
> + }
> + google->num_clks = ret;
> +
> + ret = dwc3_google_rst_init(google);
> + if (ret) {
> + ret = dev_err_probe(dev, ret, "failed to get resets\n");
> + goto err_deinit_pdom;
> + }
> +
> + ret = reset_control_bulk_deassert(google->num_rsts, google->rsts);
> + if (ret) {
> + ret = dev_err_probe(dev, ret, "failed to deassert rsts\n");
> + goto err_deinit_pdom;
> + }
> +
> + ret = dwc3_google_request_irq(google, pdev, "hs_pme", "USB HS wakeup");
> + if (ret < 0) {
> + ret = dev_err_probe(dev, ret, "failed to request hs pme irq");
> + goto err_reset_assert;
> + }
> + google->hs_pme_irq = ret;
> +
> + ret = dwc3_google_request_irq(google, pdev, "ss_pme", "USB SS wakeup");
> + if (ret < 0) {
> + ret = dev_err_probe(dev, ret, "failed to request ss pme irq");
> + goto err_reset_assert;
> + }
> + google->ss_pme_irq = ret;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + ret = dev_err_probe(dev, -ENODEV, "invalid memory\n");
> + goto err_reset_assert;
> + }
> +
> + device_init_wakeup(dev, true);
> +
> + google->dwc.dev = dev;
> + probe_data.dwc = &google->dwc;
> + probe_data.res = res;
> + probe_data.ignore_clocks_and_resets = true;
> + ret = dwc3_core_probe(&probe_data);
> + if (ret) {
> + ret = dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
> + goto err_reset_assert;
> + }
> +
> + return 0;
> +
> +err_reset_assert:
> + reset_control_bulk_assert(google->num_rsts, google->rsts);
> +
> +err_deinit_pdom:
> + dwc3_google_pm_domain_deinit(google);
> +
> + return ret;
> +}
> +
> +static void dwc3_google_remove(struct platform_device *pdev)
> +{
> + struct dwc3 *dwc = platform_get_drvdata(pdev);
> + struct dwc3_google *google = to_dwc3_google(dwc);
> +
> + dwc3_core_remove(&google->dwc);
> +
> + reset_control_bulk_assert(google->num_rsts, google->rsts);
> +
> + dwc3_google_pm_domain_deinit(google);
> +}
> +
> +static int dwc3_google_suspend(struct dwc3_google *google, pm_message_t msg)
> +{
> + if (pm_runtime_suspended(google->dev))
> + return 0;
> +
> + if (google->dwc.current_dr_role == DWC3_GCTL_PRTCAP_HOST) {
> + /*
> + * Follow dwc3_suspend_common() guidelines for deciding between
> + * a full teardown and hibernation.
> + */
> + if (PMSG_IS_AUTO(msg) || device_may_wakeup(google->dev)) {
> + dev_dbg(google->dev, "enter hibernation");
> + pm_runtime_get_sync(google->usb_top_pd);
> + device_wakeup_enable(google->usb_top_pd);
> + dwc3_google_enable_pme_irq(google);
> + google->is_hibernation = true;
> + return 0;
> + }
> + }
> +
> + reset_control_bulk_assert(google->num_rsts, google->rsts);
> + clk_bulk_disable_unprepare(google->num_clks, google->clks);
> +
> + return 0;
> +}
> +
> +static int dwc3_google_resume(struct dwc3_google *google, pm_message_t msg)
> +{
> + int ret;
> +
> + if (google->is_hibernation) {
> + dev_dbg(google->dev, "exit hibernation");
> + dwc3_google_disable_pme_irq(google);
> + device_wakeup_disable(google->usb_top_pd);
> + pm_runtime_put_sync(google->usb_top_pd);
> + google->is_hibernation = false;
> + return 0;
> + }
> +
> + if (google->is_usb2only)
> + dwc3_google_program_usb2only(google);
> +
> + ret = clk_bulk_prepare_enable(google->num_clks, google->clks);
> + if (ret)
> + return ret;
> +
> + ret = reset_control_bulk_deassert(google->num_rsts, google->rsts);
> + if (ret) {
> + clk_bulk_disable_unprepare(google->num_clks, google->clks);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int dwc3_google_pm_suspend(struct device *dev)
> +{
> + struct dwc3 *dwc = dev_get_drvdata(dev);
> + struct dwc3_google *google = to_dwc3_google(dwc);
> + int ret;
> +
> + ret = dwc3_pm_suspend(&google->dwc);
> + if (ret)
> + return ret;
> +
> + return dwc3_google_suspend(google, PMSG_SUSPEND);
> +}
> +
> +static int dwc3_google_pm_resume(struct device *dev)
> +{
> + struct dwc3 *dwc = dev_get_drvdata(dev);
> + struct dwc3_google *google = to_dwc3_google(dwc);
> + int ret;
> +
> + ret = dwc3_google_resume(google, PMSG_RESUME);
> + if (ret)
> + return ret;
> +
> + return dwc3_pm_resume(&google->dwc);
> +}
> +
> +static void dwc3_google_complete(struct device *dev)
> +{
> + struct dwc3 *dwc = dev_get_drvdata(dev);
> +
> + dwc3_pm_complete(dwc);
> +}
> +
> +static int dwc3_google_prepare(struct device *dev)
> +{
> + struct dwc3 *dwc = dev_get_drvdata(dev);
> +
> + return dwc3_pm_prepare(dwc);
> +}
> +
> +static int dwc3_google_runtime_suspend(struct device *dev)
> +{
> + struct dwc3 *dwc = dev_get_drvdata(dev);
> + struct dwc3_google *google = to_dwc3_google(dwc);
> + int ret;
> +
> + ret = dwc3_runtime_suspend(&google->dwc);
> + if (ret)
> + return ret;
> +
> + return dwc3_google_suspend(google, PMSG_AUTO_SUSPEND);
> +}
> +
> +static int dwc3_google_runtime_resume(struct device *dev)
> +{
> + struct dwc3 *dwc = dev_get_drvdata(dev);
> + struct dwc3_google *google = to_dwc3_google(dwc);
> + int ret;
> +
> + ret = dwc3_google_resume(google, PMSG_AUTO_RESUME);
> + if (ret)
> + return ret;
> +
> + return dwc3_runtime_resume(&google->dwc);
> +}
> +
> +static int dwc3_google_runtime_idle(struct device *dev)
> +{
> + return dwc3_runtime_idle(dev_get_drvdata(dev));
> +}
> +
> +static const struct dev_pm_ops dwc3_google_dev_pm_ops = {
> + SYSTEM_SLEEP_PM_OPS(dwc3_google_pm_suspend, dwc3_google_pm_resume)
> + RUNTIME_PM_OPS(dwc3_google_runtime_suspend, dwc3_google_runtime_resume,
> + dwc3_google_runtime_idle)
> + .complete = pm_sleep_ptr(dwc3_google_complete),
> + .prepare = pm_sleep_ptr(dwc3_google_prepare),
> +};
> +
> +static const struct of_device_id dwc3_google_of_match[] = {
> + { .compatible = "google,lga-dwc3" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, dwc3_google_of_match);
> +
> +static struct platform_driver dwc3_google_driver = {
> + .probe = dwc3_google_probe,
> + .remove = dwc3_google_remove,
> + .driver = {
> + .name = "google-dwc3",
Usually the name follow this convention: dwc3-<vendor>
> + .pm = pm_ptr(&dwc3_google_dev_pm_ops),
> + .of_match_table = dwc3_google_of_match,
> + },
> +};
> +
> +module_platform_driver(dwc3_google_driver);
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("DesignWare DWC3 Google Glue Driver");
> --
> 2.51.2.1041.gc1ab5b90ca-goog
>
Beside the minor naming nit:
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
BR,
Thinh
On Fri, Nov 14, 2025 at 8:24 AM Thinh Nguyen <Thinh.Nguyen@synopsys.com> wrote:
>
> On Wed, Nov 12, 2025, Roy Luo wrote:
> > Add support for the DWC3 USB controller found on Google Tensor G5
> > (codename: laguna). The controller features dual-role functionality
> > and hibernation.
> >
> > The primary focus is implementing hibernation support in host mode,
> > enabling the controller to enter a low-power state (D3). This is
> > particularly relevant during system power state transition and
> > runtime power management for power efficiency.
> > Highlights:
> > - Align suspend callback with dwc3_suspend_common() for deciding
> > between a full teardown and hibernation in host mode.
> > - Integration with `psw` (power switchable) and `top` power domains,
> > managing their states and device links to support hibernation.
> > - A notifier callback dwc3_google_usb_psw_pd_notifier() for
> > `psw` power domain events to manage controller state
> > transitions to/from D3.
> > - Coordination of the `non_sticky` reset during power state
> > transitions, asserting it on D3 entry and deasserting on D0 entry
> > in hibernation scenario.
> > - Handling of high-speed and super-speed PME interrupts
> > that are generated by remote wakeup during hibernation.
> >
> > Co-developed-by: Joy Chakraborty <joychakr@google.com>
> > Signed-off-by: Joy Chakraborty <joychakr@google.com>
> > Co-developed-by: Naveen Kumar <mnkumar@google.com>
> > Signed-off-by: Naveen Kumar <mnkumar@google.com>
> > Signed-off-by: Roy Luo <royluo@google.com>
> > ---
> > drivers/usb/dwc3/Kconfig | 10 +
> > drivers/usb/dwc3/Makefile | 1 +
> > drivers/usb/dwc3/dwc3-google.c | 628 +++++++++++++++++++++++++++++++++
> > 3 files changed, 639 insertions(+)
> > create mode 100644 drivers/usb/dwc3/dwc3-google.c
> >
> > diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> > index 4925d15084f8..bb0e4dc97da3 100644
> > --- a/drivers/usb/dwc3/Kconfig
> > +++ b/drivers/usb/dwc3/Kconfig
> > @@ -200,4 +200,14 @@ config USB_DWC3_GENERIC_PLAT
> > the dwc3 child node in the device tree.
> > Say 'Y' or 'M' here if your platform integrates DWC3 in a similar way.
> >
> > +config USB_DWC3_GOOGLE
> > + tristate "Google Platform"
> > + depends on OF && COMMON_CLK && RESET_CONTROLLER
> > + default n
> > + help
> > + Support the DesignWare Core USB3 IP found on Google Tensor
> > + SoCs, starting with the G5 generation. This driver includes
> > + support for hibernation in host mode.
> > + Say 'Y' or 'M' if you have one such device.
> > +
> > endif
> > diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> > index 96469e48ff9d..cf1cd408d938 100644
> > --- a/drivers/usb/dwc3/Makefile
> > +++ b/drivers/usb/dwc3/Makefile
> > @@ -58,3 +58,4 @@ obj-$(CONFIG_USB_DWC3_XILINX) += dwc3-xilinx.o
> > obj-$(CONFIG_USB_DWC3_OCTEON) += dwc3-octeon.o
> > obj-$(CONFIG_USB_DWC3_RTK) += dwc3-rtk.o
> > obj-$(CONFIG_USB_DWC3_GENERIC_PLAT) += dwc3-generic-plat.o
> > +obj-$(CONFIG_USB_DWC3_GOOGLE) += dwc3-google.o
> > diff --git a/drivers/usb/dwc3/dwc3-google.c b/drivers/usb/dwc3/dwc3-google.c
> > new file mode 100644
> > index 000000000000..428adf7d6049
> > --- /dev/null
> > +++ b/drivers/usb/dwc3/dwc3-google.c
> > @@ -0,0 +1,628 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * dwc3-google.c - Google DWC3 Specific Glue Layer
> > + *
> > + * Copyright (c) 2025, Google LLC
> > + * Author: Roy Luo <royluo@google.com>
> > + */
> > +
> > +#include <linux/of.h>
> > +#include <linux/bitfield.h>
> > +#include <linux/irq.h>
> > +#include <linux/clk.h>
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/reset.h>
> > +#include <linux/pm_domain.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/regmap.h>
> > +#include <linux/mfd/syscon.h>
> > +#include "core.h"
> > +#include "glue.h"
> > +
> > +/* HOST CFG registers */
> > +#define HC_STATUS_OFFSET 0x0
> > +#define HC_STATUS_CURRENT_POWER_STATE_U2PMU GENMASK(1, 0)
> > +#define HC_STATUS_CURRENT_POWER_STATE_U3PMU GENMASK(4, 3)
> > +
> > +#define HOST_CFG1_OFFSET 0x4
> > +#define HOST_CFG1_PME_EN BIT(3)
> > +#define HOST_CFG1_PM_POWER_STATE_REQUEST GENMASK(5, 4)
> > +#define HOST_CFG1_PM_POWER_STATE_D0 0x0
> > +#define HOST_CFG1_PM_POWER_STATE_D3 0x3
> > +
> > +/* USBINT registers */
> > +#define USBINT_CFG1_OFFSET 0x0
> > +#define USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK BIT(2)
> > +#define USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK BIT(3)
> > +#define USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN BIT(8)
> > +#define USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN BIT(9)
> > +#define USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR BIT(14)
> > +#define USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR BIT(15)
> > +
> > +#define USBINT_STATUS_OFFSET 0x4
> > +#define USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW BIT(2)
> > +#define USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW BIT(3)
> > +
> > +#define USBCS_TOP_CTRL_CFG1_OFFSET 0xc
> > +#define USBCS_TOP_CTRL_CFG1_USB2ONLY_MODE BIT(5)
> > +
> > +#define DWC3_GOOGLE_MAX_RESETS 4
> > +
> > +struct dwc3_google {
> > + struct device *dev;
> > + struct dwc3 dwc;
> > + struct clk_bulk_data *clks;
> > + int num_clks;
> > + struct reset_control_bulk_data rsts[DWC3_GOOGLE_MAX_RESETS];
> > + int num_rsts;
> > + struct reset_control *non_sticky_rst;
> > + struct device *usb_psw_pd;
> > + struct device_link *usb_psw_pd_dl;
> > + struct notifier_block usb_psw_pd_nb;
> > + struct device *usb_top_pd;
> > + struct device_link *usb_top_pd_dl;
> > + struct regmap *usb_cfg_regmap;
> > + unsigned int host_cfg_offset;
> > + unsigned int usbint_cfg_offset;
> > + int hs_pme_irq;
> > + int ss_pme_irq;
> > + bool is_usb2only;
> > + bool is_hibernation;
> > +};
> > +
> > +#define to_dwc3_google(d) container_of((d), struct dwc3_google, dwc)
> > +
> > +static int dwc3_google_rst_init(struct dwc3_google *google)
> > +{
> > + int ret;
> > +
> > + google->num_rsts = 4;
> > + google->rsts[0].id = "non_sticky";
> > + google->rsts[1].id = "sticky";
> > + google->rsts[2].id = "drd_bus";
> > + google->rsts[3].id = "top";
> > +
> > + ret = devm_reset_control_bulk_get_exclusive(google->dev,
> > + google->num_rsts,
> > + google->rsts);
> > +
> > + if (ret < 0)
> > + return ret;
> > +
> > + google->non_sticky_rst = google->rsts[0].rstc;
> > +
> > + return 0;
> > +}
> > +
> > +static int dwc3_google_set_pmu_state(struct dwc3_google *google, int state)
> > +{
> > + u32 reg;
> > + int ret;
> > +
> > + regmap_read(google->usb_cfg_regmap,
> > + google->host_cfg_offset + HOST_CFG1_OFFSET, ®);
> > +
> > + reg &= ~HOST_CFG1_PM_POWER_STATE_REQUEST;
> > + reg |= (FIELD_PREP(HOST_CFG1_PM_POWER_STATE_REQUEST, state) |
> > + HOST_CFG1_PME_EN);
> > + regmap_write(google->usb_cfg_regmap,
> > + google->host_cfg_offset + HOST_CFG1_OFFSET, reg);
> > +
> > + ret = regmap_read_poll_timeout(google->usb_cfg_regmap,
> > + google->host_cfg_offset + HC_STATUS_OFFSET, reg,
> > + (FIELD_GET(HC_STATUS_CURRENT_POWER_STATE_U2PMU,
> > + reg) == state &&
> > + FIELD_GET(HC_STATUS_CURRENT_POWER_STATE_U3PMU,
> > + reg) == state),
> > + 10, 10000);
> > +
> > + if (ret)
> > + dev_err(google->dev, "failed to set PMU state %d\n", state);
> > +
> > + return ret;
> > +}
> > +
> > +/*
> > + * Clear pme interrupts and report their status.
> > + * The hardware requires write-1 then write-0 sequence to clear the interrupt bits.
> > + */
> > +static u32 dwc3_google_clear_pme_irqs(struct dwc3_google *google)
> > +{
> > + u32 irq_status, reg_set, reg_clear;
> > +
> > + regmap_read(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBINT_STATUS_OFFSET, &irq_status);
> > +
> > + irq_status &= (USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW |
> > + USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW);
> > + if (!irq_status)
> > + return irq_status;
> > +
> > + regmap_read(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®_set);
> > +
> > + reg_clear = reg_set;
> > + if (irq_status & USBINT_STATUS_USBDRD_PME_GEN_U2P_INTR_STS_RAW) {
> > + reg_set |= USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR;
> > + reg_clear &= ~USBINT_CFG1_USBDRD_PME_GEN_U2_INTR_CLR;
> > + }
> > + if (irq_status & USBINT_STATUS_USBDRD_PME_GEN_U3P_INTR_STS_RAW) {
> > + reg_set |= USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR;
> > + reg_clear &= ~USBINT_CFG1_USBDRD_PME_GEN_U3_INTR_CLR;
> > + }
> > +
> > + regmap_write(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg_set);
> > + regmap_write(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg_clear);
> > +
> > + return irq_status;
> > +}
> > +
> > +static void dwc3_google_enable_pme_irq(struct dwc3_google *google)
> > +{
> > + u32 reg;
> > +
> > + regmap_read(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®);
> > + reg &= ~(USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK |
> > + USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK);
> > + reg |= (USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN |
> > + USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN);
> > + regmap_write(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg);
> > +
> > + enable_irq(google->hs_pme_irq);
> > + enable_irq(google->ss_pme_irq);
> > + enable_irq_wake(google->hs_pme_irq);
> > + enable_irq_wake(google->ss_pme_irq);
> > +}
> > +
> > +static void dwc3_google_disable_pme_irq(struct dwc3_google *google)
> > +{
> > + u32 reg;
> > +
> > + regmap_read(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, ®);
> > + reg &= ~(USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_INT_EN |
> > + USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_INT_EN);
> > + reg |= (USBINT_CFG1_USBDRD_PME_GEN_U2P_INTR_MSK |
> > + USBINT_CFG1_USBDRD_PME_GEN_U3P_INTR_MSK);
> > + regmap_write(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBINT_CFG1_OFFSET, reg);
> > +
> > + disable_irq_wake(google->hs_pme_irq);
> > + disable_irq_wake(google->ss_pme_irq);
> > + disable_irq_nosync(google->hs_pme_irq);
> > + disable_irq_nosync(google->ss_pme_irq);
> > +}
> > +
> > +static irqreturn_t dwc3_google_resume_irq(int irq, void *data)
> > +{
> > + struct dwc3_google *google = data;
> > + struct dwc3 *dwc = &google->dwc;
> > + u32 irq_status, dr_role;
> > +
> > + irq_status = dwc3_google_clear_pme_irqs(google);
> > + dr_role = dwc->current_dr_role;
> > +
> > + if (!irq_status || !google->is_hibernation ||
> > + dr_role != DWC3_GCTL_PRTCAP_HOST) {
> > + dev_dbg(google->dev, "spurious pme irq %d, hibernation %d, dr_role %u\n",
> > + irq, google->is_hibernation, dr_role);
> > + return IRQ_HANDLED;
> > + }
> > +
> > + if (dwc->xhci)
> > + pm_runtime_resume(&dwc->xhci->dev);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int dwc3_google_request_irq(struct dwc3_google *google, struct platform_device *pdev,
> > + const char *irq_name, const char *req_name)
> > +{
> > + int ret;
> > + int irq;
> > +
> > + irq = platform_get_irq_byname(pdev, irq_name);
> > + if (irq < 0) {
> > + dev_err(google->dev, "invalid irq name %s\n", irq_name);
> > + return irq;
> > + }
> > +
> > + irq_set_status_flags(irq, IRQ_NOAUTOEN);
> > + ret = devm_request_threaded_irq(google->dev, irq, NULL,
> > + dwc3_google_resume_irq,
> > + IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> > + req_name, google);
> > + if (ret < 0) {
> > + dev_err(google->dev, "failed to request irq %s\n", req_name);
> > + return ret;
> > + }
> > +
> > + return irq;
> > +}
> > +
> > +static int dwc3_google_usb_psw_pd_notifier(struct notifier_block *nb, unsigned long action, void *d)
> > +{
> > + struct dwc3_google *google = container_of(nb, struct dwc3_google, usb_psw_pd_nb);
> > + int ret;
> > +
> > + if (!google->is_hibernation)
> > + return NOTIFY_OK;
> > +
> > + if (action == GENPD_NOTIFY_OFF) {
> > + dev_dbg(google->dev, "enter D3 power state\n");
> > + dwc3_google_set_pmu_state(google, HOST_CFG1_PM_POWER_STATE_D3);
> > + ret = reset_control_assert(google->non_sticky_rst);
> > + if (ret)
> > + dev_err(google->dev, "non sticky reset assert failed: %d\n", ret);
> > + } else if (action == GENPD_NOTIFY_ON) {
> > + dev_dbg(google->dev, "enter D0 power state\n");
> > + dwc3_google_clear_pme_irqs(google);
> > + ret = reset_control_deassert(google->non_sticky_rst);
> > + if (ret)
> > + dev_err(google->dev, "non sticky reset deassert failed: %d\n", ret);
> > + dwc3_google_set_pmu_state(google, HOST_CFG1_PM_POWER_STATE_D0);
> > + }
> > +
> > + return NOTIFY_OK;
> > +}
> > +
> > +static void dwc3_google_pm_domain_deinit(struct dwc3_google *google)
> > +{
> > + if (google->usb_top_pd_dl)
> > + device_link_del(google->usb_top_pd_dl);
> > +
> > + if (!IS_ERR_OR_NULL(google->usb_top_pd)) {
> > + device_set_wakeup_capable(google->usb_top_pd, false);
> > + dev_pm_domain_detach(google->usb_top_pd, true);
> > + }
> > +
> > + if (google->usb_psw_pd_dl)
> > + device_link_del(google->usb_psw_pd_dl);
> > +
> > + if (!IS_ERR_OR_NULL(google->usb_psw_pd)) {
> > + dev_pm_genpd_remove_notifier(google->usb_psw_pd);
> > + dev_pm_domain_detach(google->usb_psw_pd, true);
> > + }
> > +}
> > +
> > +static int dwc3_google_pm_domain_init(struct dwc3_google *google)
> > +{
> > + int ret;
> > +
> > + /*
> > + * Establish PM RUNTIME link between dwc dev and its power domain usb_psw_pd,
> > + * register notifier block to handle hibernation.
> > + */
> > + google->usb_psw_pd = dev_pm_domain_attach_by_name(google->dev, "psw");
> > + if (IS_ERR_OR_NULL(google->usb_psw_pd)) {
> > + dev_err(google->dev, "failed to get psw pd");
> > + ret = google->usb_psw_pd ? PTR_ERR(google->usb_psw_pd) : -ENODATA;
> > + return ret;
> > + }
> > +
> > + google->usb_psw_pd_nb.notifier_call = dwc3_google_usb_psw_pd_notifier;
> > + ret = dev_pm_genpd_add_notifier(google->usb_psw_pd, &google->usb_psw_pd_nb);
> > + if (ret) {
> > + dev_err(google->dev, "failed to add psw pd notifier");
> > + goto err;
> > + }
> > +
> > + google->usb_psw_pd_dl = device_link_add(google->dev, google->usb_psw_pd,
> > + DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
> > + DL_FLAG_RPM_ACTIVE);
> > + if (!google->usb_psw_pd_dl) {
> > + dev_err(google->usb_psw_pd, "failed to add device link");
> > + ret = -ENODEV;
> > + goto err;
> > + }
> > +
> > + /*
> > + * usb_top_pd is the parent power domain of usb_psw_pd. Keeping usb_top_pd on
> > + * while usb_psw_pd is off places the controller in a power-gated state,
> > + * essential for hibernation. Acquire a handle to usb_top_pd and sets it as
> > + * wakeup-capable to allow the domain to be left on during system suspend.
> > + */
> > + google->usb_top_pd = dev_pm_domain_attach_by_name(google->dev, "top");
> > + if (IS_ERR_OR_NULL(google->usb_top_pd)) {
> > + dev_err(google->dev, "failed to get top pd");
> > + ret = google->usb_top_pd ? PTR_ERR(google->usb_top_pd) : -ENODATA;
> > + goto err;
> > + }
> > + device_set_wakeup_capable(google->usb_top_pd, true);
> > +
> > + google->usb_top_pd_dl = device_link_add(google->dev, google->usb_top_pd,
> > + DL_FLAG_STATELESS);
> > + if (!google->usb_top_pd_dl) {
> > + dev_err(google->usb_top_pd, "failed to add device link");
> > + ret = -ENODEV;
> > + goto err;
> > + }
> > +
> > + return 0;
> > +
> > +err:
> > + dwc3_google_pm_domain_deinit(google);
> > +
> > + return ret;
> > +}
> > +
> > +static void dwc3_google_program_usb2only(struct dwc3_google *google)
> > +{
> > + u32 reg;
> > +
> > + regmap_read(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBCS_TOP_CTRL_CFG1_OFFSET, ®);
> > + reg |= USBCS_TOP_CTRL_CFG1_USB2ONLY_MODE;
> > + regmap_write(google->usb_cfg_regmap,
> > + google->usbint_cfg_offset + USBCS_TOP_CTRL_CFG1_OFFSET, reg);
> > +}
> > +
> > +static int dwc3_google_probe(struct platform_device *pdev)
> > +{
> > + struct dwc3_probe_data probe_data = {};
> > + struct device *dev = &pdev->dev;
> > + struct dwc3_google *google;
> > + struct resource *res;
> > + int ret;
> > + u32 args[2];
> > +
> > + google = devm_kzalloc(&pdev->dev, sizeof(*google), GFP_KERNEL);
> > + if (!google)
> > + return -ENOMEM;
> > +
> > + google->dev = &pdev->dev;
> > +
> > + ret = dwc3_google_pm_domain_init(google);
> > + if (ret < 0)
> > + return dev_err_probe(dev, ret, "failed to init pdom\n");
> > +
> > + google->usb_cfg_regmap =
> > + syscon_regmap_lookup_by_phandle_args(dev->of_node,
> > + "google,usb-cfg-csr",
> > + ARRAY_SIZE(args), args);
> > + if (IS_ERR(google->usb_cfg_regmap)) {
> > + return dev_err_probe(dev, PTR_ERR(google->usb_cfg_regmap),
> > + "invalid usb cfg csr\n");
> > + }
> > +
> > + google->host_cfg_offset = args[0];
> > + google->usbint_cfg_offset = args[1];
> > +
> > + if (device_property_match_string(dev, "phy-names", "usb3-phy") < 0) {
> > + google->is_usb2only = true;
> > + dwc3_google_program_usb2only(google);
> > + }
> > +
> > + ret = devm_clk_bulk_get_all_enabled(dev, &google->clks);
> > + if (ret < 0) {
> > + ret = dev_err_probe(dev, ret, "failed to get and enable clks\n");
> > + goto err_deinit_pdom;
> > + }
> > + google->num_clks = ret;
> > +
> > + ret = dwc3_google_rst_init(google);
> > + if (ret) {
> > + ret = dev_err_probe(dev, ret, "failed to get resets\n");
> > + goto err_deinit_pdom;
> > + }
> > +
> > + ret = reset_control_bulk_deassert(google->num_rsts, google->rsts);
> > + if (ret) {
> > + ret = dev_err_probe(dev, ret, "failed to deassert rsts\n");
> > + goto err_deinit_pdom;
> > + }
> > +
> > + ret = dwc3_google_request_irq(google, pdev, "hs_pme", "USB HS wakeup");
> > + if (ret < 0) {
> > + ret = dev_err_probe(dev, ret, "failed to request hs pme irq");
> > + goto err_reset_assert;
> > + }
> > + google->hs_pme_irq = ret;
> > +
> > + ret = dwc3_google_request_irq(google, pdev, "ss_pme", "USB SS wakeup");
> > + if (ret < 0) {
> > + ret = dev_err_probe(dev, ret, "failed to request ss pme irq");
> > + goto err_reset_assert;
> > + }
> > + google->ss_pme_irq = ret;
> > +
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + if (!res) {
> > + ret = dev_err_probe(dev, -ENODEV, "invalid memory\n");
> > + goto err_reset_assert;
> > + }
> > +
> > + device_init_wakeup(dev, true);
> > +
> > + google->dwc.dev = dev;
> > + probe_data.dwc = &google->dwc;
> > + probe_data.res = res;
> > + probe_data.ignore_clocks_and_resets = true;
> > + ret = dwc3_core_probe(&probe_data);
> > + if (ret) {
> > + ret = dev_err_probe(dev, ret, "failed to register DWC3 Core\n");
> > + goto err_reset_assert;
> > + }
> > +
> > + return 0;
> > +
> > +err_reset_assert:
> > + reset_control_bulk_assert(google->num_rsts, google->rsts);
> > +
> > +err_deinit_pdom:
> > + dwc3_google_pm_domain_deinit(google);
> > +
> > + return ret;
> > +}
> > +
> > +static void dwc3_google_remove(struct platform_device *pdev)
> > +{
> > + struct dwc3 *dwc = platform_get_drvdata(pdev);
> > + struct dwc3_google *google = to_dwc3_google(dwc);
> > +
> > + dwc3_core_remove(&google->dwc);
> > +
> > + reset_control_bulk_assert(google->num_rsts, google->rsts);
> > +
> > + dwc3_google_pm_domain_deinit(google);
> > +}
> > +
> > +static int dwc3_google_suspend(struct dwc3_google *google, pm_message_t msg)
> > +{
> > + if (pm_runtime_suspended(google->dev))
> > + return 0;
> > +
> > + if (google->dwc.current_dr_role == DWC3_GCTL_PRTCAP_HOST) {
> > + /*
> > + * Follow dwc3_suspend_common() guidelines for deciding between
> > + * a full teardown and hibernation.
> > + */
> > + if (PMSG_IS_AUTO(msg) || device_may_wakeup(google->dev)) {
> > + dev_dbg(google->dev, "enter hibernation");
> > + pm_runtime_get_sync(google->usb_top_pd);
> > + device_wakeup_enable(google->usb_top_pd);
> > + dwc3_google_enable_pme_irq(google);
> > + google->is_hibernation = true;
> > + return 0;
> > + }
> > + }
> > +
> > + reset_control_bulk_assert(google->num_rsts, google->rsts);
> > + clk_bulk_disable_unprepare(google->num_clks, google->clks);
> > +
> > + return 0;
> > +}
> > +
> > +static int dwc3_google_resume(struct dwc3_google *google, pm_message_t msg)
> > +{
> > + int ret;
> > +
> > + if (google->is_hibernation) {
> > + dev_dbg(google->dev, "exit hibernation");
> > + dwc3_google_disable_pme_irq(google);
> > + device_wakeup_disable(google->usb_top_pd);
> > + pm_runtime_put_sync(google->usb_top_pd);
> > + google->is_hibernation = false;
> > + return 0;
> > + }
> > +
> > + if (google->is_usb2only)
> > + dwc3_google_program_usb2only(google);
> > +
> > + ret = clk_bulk_prepare_enable(google->num_clks, google->clks);
> > + if (ret)
> > + return ret;
> > +
> > + ret = reset_control_bulk_deassert(google->num_rsts, google->rsts);
> > + if (ret) {
> > + clk_bulk_disable_unprepare(google->num_clks, google->clks);
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int dwc3_google_pm_suspend(struct device *dev)
> > +{
> > + struct dwc3 *dwc = dev_get_drvdata(dev);
> > + struct dwc3_google *google = to_dwc3_google(dwc);
> > + int ret;
> > +
> > + ret = dwc3_pm_suspend(&google->dwc);
> > + if (ret)
> > + return ret;
> > +
> > + return dwc3_google_suspend(google, PMSG_SUSPEND);
> > +}
> > +
> > +static int dwc3_google_pm_resume(struct device *dev)
> > +{
> > + struct dwc3 *dwc = dev_get_drvdata(dev);
> > + struct dwc3_google *google = to_dwc3_google(dwc);
> > + int ret;
> > +
> > + ret = dwc3_google_resume(google, PMSG_RESUME);
> > + if (ret)
> > + return ret;
> > +
> > + return dwc3_pm_resume(&google->dwc);
> > +}
> > +
> > +static void dwc3_google_complete(struct device *dev)
> > +{
> > + struct dwc3 *dwc = dev_get_drvdata(dev);
> > +
> > + dwc3_pm_complete(dwc);
> > +}
> > +
> > +static int dwc3_google_prepare(struct device *dev)
> > +{
> > + struct dwc3 *dwc = dev_get_drvdata(dev);
> > +
> > + return dwc3_pm_prepare(dwc);
> > +}
> > +
> > +static int dwc3_google_runtime_suspend(struct device *dev)
> > +{
> > + struct dwc3 *dwc = dev_get_drvdata(dev);
> > + struct dwc3_google *google = to_dwc3_google(dwc);
> > + int ret;
> > +
> > + ret = dwc3_runtime_suspend(&google->dwc);
> > + if (ret)
> > + return ret;
> > +
> > + return dwc3_google_suspend(google, PMSG_AUTO_SUSPEND);
> > +}
> > +
> > +static int dwc3_google_runtime_resume(struct device *dev)
> > +{
> > + struct dwc3 *dwc = dev_get_drvdata(dev);
> > + struct dwc3_google *google = to_dwc3_google(dwc);
> > + int ret;
> > +
> > + ret = dwc3_google_resume(google, PMSG_AUTO_RESUME);
> > + if (ret)
> > + return ret;
> > +
> > + return dwc3_runtime_resume(&google->dwc);
> > +}
> > +
> > +static int dwc3_google_runtime_idle(struct device *dev)
> > +{
> > + return dwc3_runtime_idle(dev_get_drvdata(dev));
> > +}
> > +
> > +static const struct dev_pm_ops dwc3_google_dev_pm_ops = {
> > + SYSTEM_SLEEP_PM_OPS(dwc3_google_pm_suspend, dwc3_google_pm_resume)
> > + RUNTIME_PM_OPS(dwc3_google_runtime_suspend, dwc3_google_runtime_resume,
> > + dwc3_google_runtime_idle)
> > + .complete = pm_sleep_ptr(dwc3_google_complete),
> > + .prepare = pm_sleep_ptr(dwc3_google_prepare),
> > +};
> > +
> > +static const struct of_device_id dwc3_google_of_match[] = {
> > + { .compatible = "google,lga-dwc3" },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(of, dwc3_google_of_match);
> > +
> > +static struct platform_driver dwc3_google_driver = {
> > + .probe = dwc3_google_probe,
> > + .remove = dwc3_google_remove,
> > + .driver = {
> > + .name = "google-dwc3",
>
> Usually the name follow this convention: dwc3-<vendor>
>
> > + .pm = pm_ptr(&dwc3_google_dev_pm_ops),
> > + .of_match_table = dwc3_google_of_match,
> > + },
> > +};
> > +
> > +module_platform_driver(dwc3_google_driver);
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("DesignWare DWC3 Google Glue Driver");
> > --
> > 2.51.2.1041.gc1ab5b90ca-goog
> >
>
> Beside the minor naming nit:
>
> Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
>
> BR,
> Thinh
Hi Thinh,
Sending out a new version with the corrected naming and the Acked-by
tag appended.
Thanks,
Roy Luo
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