usb/penwell_otg: WA: reset controller to recover from PHY issue in device mode.

BZ: 22901

This patch is a workaround solution, when PHY stop working due to
Hardware issue, add ulpi_polling to detect the error and reset to
recover from bad state.

As this PHY issue has low reproduce rate, so add one debug interface
(inputs/ulpi_err)to trigger it manually, only for debug and test.

This workaround should be removed once we got a final hardware fix.
This change is for MFLD only.

Change-Id: I873122b8eac2cbf8c176ee624d436e04c4384323
Signed-off-by: Wu, Hao <hao.wu@intel.com>
Reviewed-on: http://android.intel.com:8080/34496
Reviewed-by: Tang, Richard <richard.tang@intel.com>
Reviewed-by: Meng, Zhe <zhe.meng@intel.com>
Tested-by: Meng, Zhe <zhe.meng@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

diff --git a/drivers/usb/otg/penwell_otg.c b/drivers/usb/otg/penwell_otg.c
index 791f22c..8321a9e 100644 (file)
--- a/drivers/usb/otg/penwell_otg.c
+++ b/drivers/usb/otg/penwell_otg.c
@@ -2124,6 +2124,47 @@ static void penwell_otg_hnp_poll_work(struct work_struct *work)
        }
 }
 
+static void penwell_otg_start_ulpi_poll(void)
+{
+       struct penwell_otg              *pnw = the_transceiver;
+
+       schedule_delayed_work(&pnw->ulpi_poll_work, HZ);
+}
+
+static void penwell_otg_continue_ulpi_poll(void)
+{
+       struct penwell_otg              *pnw = the_transceiver;
+
+       schedule_delayed_work(&pnw->ulpi_poll_work, HZ);
+}
+
+static void penwell_otg_ulpi_poll_work(struct work_struct *work)
+{
+       struct penwell_otg              *pnw = the_transceiver;
+       struct intel_mid_otg_xceiv      *iotg = &pnw->iotg;
+       u8                              data;
+
+       if (iotg->otg.state != OTG_STATE_B_PERIPHERAL)
+               return;
+
+       if (penwell_otg_ulpi_read(iotg, 0x16, &data)) {
+               dev_err(pnw->dev, "ulpi read time out by polling\n");
+               iotg->hsm.ulpi_error = 1;
+               iotg->hsm.ulpi_polling = 0;
+               penwell_update_transceiver();
+       } else if (data != 0x5A) {
+               dev_err(pnw->dev, "ulpi read value incorrect by polling\n");
+               iotg->hsm.ulpi_error = 1;
+               iotg->hsm.ulpi_polling = 0;
+               penwell_update_transceiver();
+       } else {
+               dev_dbg(pnw->dev, "ulpi fine by polling\n");
+               iotg->hsm.ulpi_error = 0;
+               iotg->hsm.ulpi_polling = 1;
+               penwell_otg_continue_ulpi_poll();
+       }
+}
+
 static void penwell_otg_work(struct work_struct *work)
 {
        struct penwell_otg              *pnw = container_of(work,
@@ -2333,6 +2374,10 @@ static void penwell_otg_work(struct work_struct *work)
 
                        penwell_otg_eye_diagram_optimize();
 
+                       /* MFLD WA for PHY issue */
+                       if (!is_clovertrail(pdev))
+                               penwell_otg_start_ulpi_poll();
+
                        iotg->otg.state = OTG_STATE_B_PERIPHERAL;
 
                } else if ((hsm->b_bus_req || hsm->power_up || hsm->adp_change
@@ -2408,9 +2453,28 @@ static void penwell_otg_work(struct work_struct *work)
 
                        iotg->otg.state = OTG_STATE_A_IDLE;
                        penwell_update_transceiver();
+               } else if (hsm->ulpi_error) {
+                       /* WA: try to recover once detected PHY issue */
+                       hsm->ulpi_error = 0;
+
+                       cancel_delayed_work_sync(&pnw->ulpi_poll_work);
+
+                       if (iotg->stop_peripheral)
+                               iotg->stop_peripheral(iotg);
+
+                       msleep(2000);
+
+                       if (iotg->start_peripheral)
+                               iotg->start_peripheral(iotg);
+
+                       if (!is_clovertrail(pdev))
+                               penwell_otg_start_ulpi_poll();
+
                } else if (!hsm->b_sess_vld || hsm->id == ID_ACA_B) {
                        /* Move to B_IDLE state, VBUS off/ACA */
 
+                       cancel_delayed_work(&pnw->ulpi_poll_work);
+
                        if (hsm->id == ID_ACA_B)
                                penwell_otg_update_chrg_cap(CHRG_ACA,
                                                        CHRG_CURR_ACA);
@@ -3377,7 +3441,9 @@ show_hsm(struct device *_dev, struct device_attribute *attr, char *buf)
                "a_bus_drop = \t%d\n"
                "a_bus_req = \t%d\n"
                "a_clr_err = \t%d\n"
-               "b_bus_req = \t%d\n",
+               "b_bus_req = \t%d\n"
+               "ulpi_error = \t%d\n"
+               "ulpi_polling = \t%d\n",
                state_string(iotg->otg.state),
                iotg->hsm.a_bus_resume,
                iotg->hsm.a_bus_suspend,
@@ -3414,7 +3480,9 @@ show_hsm(struct device *_dev, struct device_attribute *attr, char *buf)
                iotg->hsm.a_bus_drop,
                iotg->hsm.a_bus_req,
                iotg->hsm.a_clr_err,
-               iotg->hsm.b_bus_req
+               iotg->hsm.b_bus_req,
+               iotg->hsm.ulpi_error,
+               iotg->hsm.ulpi_polling
                );
        size -= t;
        next += t;
@@ -3640,11 +3708,29 @@ set_a_clr_err(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR(a_clr_err, S_IRUGO | S_IWUSR | S_IWGRP, NULL, set_a_clr_err);
 
+static ssize_t
+set_ulpi_err(struct device *dev, struct device_attribute *attr,
+               const char *buf, size_t count)
+{
+       struct penwell_otg              *pnw = the_transceiver;
+       struct intel_mid_otg_xceiv      *iotg = &pnw->iotg;
+
+       dev_dbg(pnw->dev, "trigger ulpi error manually\n");
+
+       iotg->hsm.ulpi_error = 1;
+
+       penwell_update_transceiver();
+
+       return count;
+}
+static DEVICE_ATTR(ulpi_err, S_IRUGO | S_IWUSR | S_IWGRP, NULL, set_ulpi_err);
+
 static struct attribute *inputs_attrs[] = {
        &dev_attr_a_bus_req.attr,
        &dev_attr_a_bus_drop.attr,
        &dev_attr_b_bus_req.attr,
        &dev_attr_a_clr_err.attr,
+       &dev_attr_ulpi_err.attr,
        NULL,
 };
 
@@ -3741,6 +3827,7 @@ static int penwell_otg_probe(struct pci_dev *pdev,
        }
        INIT_WORK(&pnw->work, penwell_otg_work);
        INIT_WORK(&pnw->hnp_poll_work, penwell_otg_hnp_poll_work);
+       INIT_DELAYED_WORK(&pnw->ulpi_poll_work, penwell_otg_ulpi_poll_work);
 
        /* OTG common part */
        pnw->dev = &pdev->dev;
@@ -3858,6 +3945,12 @@ static int penwell_otg_probe(struct pci_dev *pdev,
        reset_otg();
        init_hsm();
 
+       /* Workaround for PHY issue */
+       penwell_otg_phy_low_power(0);
+       retval = penwell_otg_ulpi_write(&pnw->iotg, 0x16, 0x5a);
+       if (retval)
+               dev_err(pnw->dev, "ulpi write in init failed\n");
+
        /* we need to set active early or the first irqs will be ignored */
        pm_runtime_set_active(&pdev->dev);
 

diff --git a/include/linux/usb/intel_mid_otg.h b/include/linux/usb/intel_mid_otg.h
index de721ca..eb25a3a 100644 (file)
--- a/include/linux/usb/intel_mid_otg.h
+++ b/include/linux/usb/intel_mid_otg.h
@@ -91,6 +91,8 @@ struct otg_hsm {
 
        /* Others */
        int vbus_srp_up;
+       int ulpi_error;
+       int ulpi_polling;
 
        /* Test Mode */
        int otg_srp_reqd;

diff --git a/include/linux/usb/penwell_otg.h b/include/linux/usb/penwell_otg.h
index 38d3eb3..5b67e69 100644 (file)
--- a/include/linux/usb/penwell_otg.h
+++ b/include/linux/usb/penwell_otg.h
@@ -426,6 +426,7 @@ struct penwell_otg {
 
        struct work_struct              work;
        struct work_struct              hnp_poll_work;
+       struct delayed_work             ulpi_poll_work;
        struct workqueue_struct         *qwork;
 
        struct timer_list               hsm_timer;