Since EHCI/OHCI controllers on R-Car Gen3 SoCs are possible to
be getting stuck very rarely after a full/low usb device was
disconnected. To detect/recover from such a situation, the controllers
require a special way which poll the EHCI PORTSC register and changes
the OHCI functional state.
So, this patch adds a polling timer into the ehci-platform driver,
and if the ehci driver detects the issue by the EHCI PORTSC register,
the ehci driver removes a companion device (= the OHCI controller)
to change the OHCI functional state to USB Reset once. And then,
the ehci driver adds the companion device again.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
drivers/usb/host/ehci-platform.c | 104 +++++++++++++++++++++++++++++++++++++++
1 file changed, 104 insertions(+)
diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index 769749c..fc6bb06 100644
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -29,6 +29,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
+#include <linux/timer.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/usb/ehci_pdriver.h>
@@ -44,6 +45,9 @@ struct ehci_platform_priv {
struct clk *clks[EHCI_MAX_CLKS];
struct reset_control *rsts;
bool reset_on_resume;
+ bool quirk_poll;
+ struct timer_list poll_timer;
+ struct work_struct poll_work;
};
static const char hcd_name[] = "ehci-platform";
@@ -118,6 +122,88 @@ static struct usb_ehci_pdata ehci_platform_defaults = {
.power_off = ehci_platform_power_off,
};
+static bool ehci_platform_quirk_poll_check_condition(struct ehci_hcd *ehci)
+{
+ u32 port_status = ehci_readl(ehci, &ehci->regs->port_status[0]);
+
+ if (!(port_status & PORT_OWNER) && /* PO == 0b */
+ port_status & PORT_POWER && /* PP == 1b */
+ !(port_status & PORT_CONNECT) && /* CCS == 0b */
+ port_status & GENMASK(11, 10)) /* LS != 00b */
+ return true;
+
+ return false;
+}
+
+static void ehci_platform_quirk_poll_rebind_companion(struct ehci_hcd *ehci)
+{
+ struct device *companion_dev;
+ struct usb_hcd *hcd = ehci_to_hcd(ehci);
+
+ companion_dev = usb_of_get_companion_dev(hcd->self.controller);
+ if (!companion_dev)
+ return;
+
+ device_release_driver(companion_dev);
+ if (device_attach(companion_dev) < 0)
+ ehci_err(ehci, "%s: failed\n", __func__);
+
+ put_device(companion_dev);
+}
+
+static void ehci_platform_quirk_poll_start_timer(struct ehci_platform_priv *p)
+{
+ mod_timer(&p->poll_timer, jiffies + msecs_to_jiffies(1000));
+}
+
+static void ehci_platform_quirk_poll_work(struct work_struct *work)
+{
+ struct ehci_platform_priv *priv =
+ container_of(work, struct ehci_platform_priv, poll_work);
+ struct ehci_hcd *ehci = container_of((void *)priv, struct ehci_hcd,
+ priv);
+ int i;
+
+ usleep_range(4000, 8000);
+
+ for (i = 0; i < 2; i++) {
+ udelay(10);
+ if (!ehci_platform_quirk_poll_check_condition(ehci))
+ goto out;
+ }
+
+ ehci_dbg(ehci, "%s: detected getting stuck. rebind now!\n", __func__);
+ ehci_platform_quirk_poll_rebind_companion(ehci);
+
+out:
+ ehci_platform_quirk_poll_start_timer(priv);
+}
+
+static void ehci_platform_quirk_poll_timer(struct timer_list *t)
+{
+ struct ehci_platform_priv *priv = from_timer(priv, t, poll_timer);
+ struct ehci_hcd *ehci = container_of((void *)priv, struct ehci_hcd,
+ priv);
+
+ if (ehci_platform_quirk_poll_check_condition(ehci))
+ schedule_work(&priv->poll_work);
+ else
+ ehci_platform_quirk_poll_start_timer(priv);
+}
+
+static void ehci_platform_quirk_poll_init(struct ehci_platform_priv *priv)
+{
+ INIT_WORK(&priv->poll_work, ehci_platform_quirk_poll_work);
+ timer_setup(&priv->poll_timer, ehci_platform_quirk_poll_timer, 0);
+ ehci_platform_quirk_poll_start_timer(priv);
+}
+
+static void ehci_platform_quirk_poll_end(struct ehci_platform_priv *priv)
+{
+ del_timer_sync(&priv->poll_timer);
+ flush_work(&priv->poll_work);
+}
+
static int ehci_platform_probe(struct platform_device *dev)
{
struct usb_hcd *hcd;
@@ -176,6 +262,10 @@ static int ehci_platform_probe(struct platform_device *dev)
"has-transaction-translator"))
hcd->has_tt = 1;
+ if (of_property_read_bool(dev->dev.of_node,
+ "needs-polling-to-avoid-stuck"))
+ priv->quirk_poll = true;
+
for (clk = 0; clk < EHCI_MAX_CLKS; clk++) {
priv->clks[clk] = of_clk_get(dev->dev.of_node, clk);
if (IS_ERR(priv->clks[clk])) {
@@ -247,6 +337,9 @@ static int ehci_platform_probe(struct platform_device *dev)
device_enable_async_suspend(hcd->self.controller);
platform_set_drvdata(dev, hcd);
+ if (priv->quirk_poll)
+ ehci_platform_quirk_poll_init(priv);
+
return err;
err_power:
@@ -273,6 +366,9 @@ static int ehci_platform_remove(struct platform_device *dev)
struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
int clk;
+ if (priv->quirk_poll)
+ ehci_platform_quirk_poll_end(priv);
+
usb_remove_hcd(hcd);
if (pdata->power_off)
@@ -297,9 +393,13 @@ static int ehci_platform_suspend(struct device *dev)
struct usb_hcd *hcd = dev_get_drvdata(dev);
struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
struct platform_device *pdev = to_platform_device(dev);
+ struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
bool do_wakeup = device_may_wakeup(dev);
int ret;
+ if (priv->quirk_poll)
+ ehci_platform_quirk_poll_end(priv);
+
ret = ehci_suspend(hcd, do_wakeup);
if (ret)
return ret;
@@ -331,6 +431,10 @@ static int ehci_platform_resume(struct device *dev)
}
ehci_resume(hcd, priv->reset_on_resume);
+
+ if (priv->quirk_poll)
+ ehci_platform_quirk_poll_init(priv);
+
return 0;
}
#endif /* CONFIG_PM_SLEEP */
--
2.7.4
