[PATCH 1/2] usb: dwc3: core: Introduce dwc3_device_reinit()
From: Roger Quadros
Date: Wed Mar 16 2016 - 09:06:12 EST
We will need this function for a workaround.
The function issues a softreset only to the device
controller and performs minimal re-initialization
so that the device controller can be usable.
As some code is similar to dwc3_core_init() take out
common code into dwc3_get_gctl_quirks().
We add a new member (prtcap_mode) to struct dwc3 to
keep track of the current mode in the PRTCAPDIR register.
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
---
drivers/usb/dwc3/core.c | 142 +++++++++++++++++++++++++++++++++---------------
drivers/usb/dwc3/core.h | 3 +
2 files changed, 102 insertions(+), 43 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 17fd8144..3b09494 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -58,6 +58,7 @@ void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
reg |= DWC3_GCTL_PRTCAPDIR(mode);
dwc3_writel(dwc->regs, DWC3_GCTL, reg);
+ dwc->prtcap_mode = mode;
}
/**
@@ -525,53 +526,16 @@ static int dwc3_phy_setup(struct dwc3 *dwc)
}
/**
- * dwc3_core_init - Low-level initialization of DWC3 Core
+ * dwc3_get_gctl_quirks - Prepare GCTL register content with quirks
+ * and workarounds.
* @dwc: Pointer to our controller context structure
*
- * Returns 0 on success otherwise negative errno.
+ * Returns 32-bit content that must be written into GCTL by caller.
*/
-static int dwc3_core_init(struct dwc3 *dwc)
+static u32 dwc3_get_gctl_quirks(struct dwc3 *dwc)
{
- u32 hwparams4 = dwc->hwparams.hwparams4;
- u32 reg;
- int ret;
-
- reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
- /* This should read as U3 followed by revision number */
- if ((reg & DWC3_GSNPSID_MASK) == 0x55330000) {
- /* Detected DWC_usb3 IP */
- dwc->revision = reg;
- } else if ((reg & DWC3_GSNPSID_MASK) == 0x33310000) {
- /* Detected DWC_usb31 IP */
- dwc->revision = dwc3_readl(dwc->regs, DWC3_VER_NUMBER);
- dwc->revision |= DWC3_REVISION_IS_DWC31;
- } else {
- dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
- ret = -ENODEV;
- goto err0;
- }
-
- /*
- * Write Linux Version Code to our GUID register so it's easy to figure
- * out which kernel version a bug was found.
- */
- dwc3_writel(dwc->regs, DWC3_GUID, LINUX_VERSION_CODE);
-
- /* Handle USB2.0-only core configuration */
- if (DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3) ==
- DWC3_GHWPARAMS3_SSPHY_IFC_DIS) {
- if (dwc->maximum_speed == USB_SPEED_SUPER)
- dwc->maximum_speed = USB_SPEED_HIGH;
- }
-
- /* issue device SoftReset too */
- ret = dwc3_soft_reset(dwc);
- if (ret)
- goto err0;
-
- ret = dwc3_core_soft_reset(dwc);
- if (ret)
- goto err0;
+ u32 reg;
+ u32 hwparams4 = dwc->hwparams.hwparams4;
reg = dwc3_readl(dwc->regs, DWC3_GCTL);
reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
@@ -639,6 +603,59 @@ static int dwc3_core_init(struct dwc3 *dwc)
if (dwc->revision < DWC3_REVISION_190A)
reg |= DWC3_GCTL_U2RSTECN;
+ return reg;
+}
+
+/**
+ * dwc3_core_init - Low-level initialization of DWC3 Core
+ * @dwc: Pointer to our controller context structure
+ *
+ * Returns 0 on success otherwise negative errno.
+ */
+static int dwc3_core_init(struct dwc3 *dwc)
+{
+ u32 reg;
+ int ret;
+
+ reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
+ /* This should read as U3 followed by revision number */
+ if ((reg & DWC3_GSNPSID_MASK) == 0x55330000) {
+ /* Detected DWC_usb3 IP */
+ dwc->revision = reg;
+ } else if ((reg & DWC3_GSNPSID_MASK) == 0x33310000) {
+ /* Detected DWC_usb31 IP */
+ dwc->revision = dwc3_readl(dwc->regs, DWC3_VER_NUMBER);
+ dwc->revision |= DWC3_REVISION_IS_DWC31;
+ } else {
+ dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
+ ret = -ENODEV;
+ goto err0;
+ }
+
+ /*
+ * Write Linux Version Code to our GUID register so it's easy to figure
+ * out which kernel version a bug was found.
+ */
+ dwc3_writel(dwc->regs, DWC3_GUID, LINUX_VERSION_CODE);
+
+ /* Handle USB2.0-only core configuration */
+ if (DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3) ==
+ DWC3_GHWPARAMS3_SSPHY_IFC_DIS) {
+ if (dwc->maximum_speed == USB_SPEED_SUPER)
+ dwc->maximum_speed = USB_SPEED_HIGH;
+ }
+
+ /* issue device SoftReset too */
+ ret = dwc3_soft_reset(dwc);
+ if (ret)
+ goto err0;
+
+ ret = dwc3_core_soft_reset(dwc);
+ if (ret)
+ goto err0;
+
+ reg = dwc3_get_gctl_quirks(dwc);
+
dwc3_core_num_eps(dwc);
dwc3_writel(dwc->regs, DWC3_GCTL, reg);
@@ -666,6 +683,45 @@ err0:
return ret;
}
+/**
+ * dwc3_device_reinit - Reset device controller and re-initialize.
+ * Can currently be called only if dwc->prtcap_mode == DWC3_GCTL_PRTCAP_DEVICE
+ * @dwc: Pointer to our controller context structure
+ *
+ * Returns 0 on success otherwise negative errno.
+ */
+int dwc3_device_reinit(struct dwc3 *dwc)
+{
+ u32 reg;
+ int ret;
+
+ if (dwc->prtcap_mode != DWC3_GCTL_PRTCAP_DEVICE) {
+ dev_err(dwc->dev, "%s can't be used for current_mode %d\n",
+ __func__, dwc->prtcap_mode);
+ return -EINVAL;
+ }
+
+ dwc3_free_scratch_buffers(dwc);
+
+ ret = dwc3_soft_reset(dwc);
+ if (ret)
+ return ret;
+
+ reg = dwc3_get_gctl_quirks(dwc);
+ dwc3_writel(dwc->regs, DWC3_GCTL, reg);
+
+ ret = dwc3_event_buffers_setup(dwc);
+ if (ret) {
+ dev_err(dwc->dev, "failed to setup event buffers\n");
+ return ret;
+ }
+
+ /* Set portcap. For now we support device only */
+ dwc3_set_mode(dwc, DWC3_GCTL_PRTCAP_DEVICE);
+
+ return ret;
+}
+
static void dwc3_core_exit(struct dwc3 *dwc)
{
dwc3_free_scratch_buffers(dwc);
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 6254b2f..2bea1ac 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -672,6 +672,7 @@ struct dwc3_scratchpad_array {
* @maximum_speed: maximum speed requested (mainly for testing purposes)
* @revision: revision register contents
* @dr_mode: requested mode of operation
+ * @prtcap_mode: current mode of operation written to PRTCAPDIR
* @usb2_phy: pointer to USB2 PHY
* @usb3_phy: pointer to USB3 PHY
* @usb2_generic_phy: pointer to USB2 PHY
@@ -774,6 +775,7 @@ struct dwc3 {
size_t regs_size;
enum usb_dr_mode dr_mode;
+ u32 prtcap_mode;
/* used for suspend/resume */
u32 dcfg;
@@ -1026,6 +1028,7 @@ struct dwc3_gadget_ep_cmd_params {
/* prototypes */
void dwc3_set_mode(struct dwc3 *dwc, u32 mode);
int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc);
+int dwc3_device_reinit(struct dwc3 *dwc);
/* check whether we are on the DWC_usb31 core */
static inline bool dwc3_is_usb31(struct dwc3 *dwc)
--
2.5.0