Re: [PATCH v3] usb: chipidea: Use extcon framework for VBUS and ID detect

On Fri, Jun 05, 2015 at 10:37:07AM +0300, Ivan T. Ivanov wrote:

On Fri, 2015-06-05 at 15:03 +0800, Peter Chen wrote:

quoted

On Tue, Jun 02, 2015 at 04:14:33PM +0300, Ivan T. Ivanov wrote:

quoted

On recent Qualcomm platforms VBUS and ID lines are not routed to
USB PHY LINK controller. Use extcon framework to receive connect
and disconnect ID and VBUS notification.

Signed-off-by: Ivan T. Ivanov ivanov-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
Changes sice v2 [1].

* Simulate IRQ on extcon event - used to trigger OTG state machine.

No, you may not need to trigger complicate OTG FSM, instead, the
role switch based on ID value is ok.

I have tried this also, but I decided that using IRQ simulation
will handle all use cases.

After thinking more, I agree this solution

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I have to admit that I couldn't test complete Chipidea OTG state machine,
because my setup is little weird. I am using "qcom,usb-otg-ci" as PHY/OTG
provider, "qcom,ehci-host" as host controller driver and "qcom,ci-hdrc" for
device role.

Then, I am puzzled what kinds of flow you have tested in this patch?
extcon is really needed for chipidea core, but I hope we have tested
patch set based on it. Rob Herring have tested Marvell's host controller
can also use chipidea host driver, I think the same for qualcomm's.
The otg flow at phy-msm-usb.c can be removed and use chipidea's instead, and
only remain phy part at it.

I have tried this, but there is too many legacy code which is supposed to 
handle old platforms and I can not distinguish, which should stay in and
what could be taken out. I will take a look again. 

Yeah, you can test your own patch.

quoted

Current role switch and vbus flow are based on otgsc register, you can
improve it by adding extcon support.

I am not sure that I get this. Isn't exactly what this patch does?

Yes, you are right, see my further comments for your patch.

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+static int ci_vbus_notifier(struct notifier_block *nb, unsigned long event,
+                                                       void *ptr)
+{
+       struct ci_hdrc_cable *vbus = container_of(nb, struct ci_hdrc_cable, nb);
+       struct ci_hdrc *ci = vbus->ci;
+
+       if (event)
+               vbus->state = true;
+       else
+               vbus->state = false;
+
+       vbus->changed = true;
+
+       ci_irq(ci->irq, ci);
+       return NOTIFY_DONE;
+}
+
+static int ci_id_notifier(struct notifier_block *nb, unsigned long event,
+                                       void *ptr)
+{
+       struct ci_hdrc_cable *id = container_of(nb, struct ci_hdrc_cable, nb);
+       struct ci_hdrc *ci = id->ci;
+
+       if (event)
+               id->state = false;
+       else
+               id->state = true;
+
+       id->changed = true;
+

How to know the id value must be changed?
How about using id->changed = (event != id->state) ? true : false?
of cos, it needs to move before if {}.

The same change may need to add to vbus notifier.

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+       ci_irq(ci->irq, ci);
+       return NOTIFY_DONE;
+}
+
 static int ci_get_platdata(struct device *dev,
                struct ci_hdrc_platform_data *platdata)
 {
+       struct extcon_dev *ext_vbus, *ext_id;
+       struct ci_hdrc_cable *cable;
+       int ret;
+
        if (!platdata->phy_mode)
                platdata->phy_mode = of_usb_get_phy_mode(dev->of_node);

@@ -591,9 +630,89 @@ static int ci_get_platdata(struct device *dev,
        if (of_usb_get_maximum_speed(dev->of_node) == USB_SPEED_FULL)
                platdata->flags |= CI_HDRC_FORCE_FULLSPEED;

+       ext_id = ERR_PTR(-ENODEV);
+       ext_vbus = ERR_PTR(-ENODEV);
+       if (of_property_read_bool(dev->of_node, "extcon")) {
+               /* Each one of them is not mandatory */
+               ext_vbus = extcon_get_edev_by_phandle(dev, 0);
+               if (IS_ERR(ext_vbus) && PTR_ERR(ext_vbus) != -ENODEV)
+                       return PTR_ERR(ext_vbus);
+
+               ext_id = extcon_get_edev_by_phandle(dev, 1);
+               if (IS_ERR(ext_id) && PTR_ERR(ext_id) != -ENODEV)
+                       return PTR_ERR(ext_id);
+       }
+
+       cable = &platdata->vbus_extcon;
+       cable->nb.notifier_call = ci_vbus_notifier;
+       cable->edev = ext_vbus;
+
+       if (!IS_ERR(ext_vbus)) {
+               ret = extcon_get_cable_state(cable->edev, "USB");

I have not read extcon framework too much, but seems you should only
can get cable state after register it (through ci_extcon_register)?
ci_get_platdata is called before ci core probe.

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+               if (ret)
+                       cable->state = true;
+               else
+                       cable->state = false;
+       }
+
+       cable = &platdata->id_extcon;
+       cable->nb.notifier_call = ci_id_notifier;
+       cable->edev = ext_id;
+
+       if (!IS_ERR(ext_id)) {
+               ret = extcon_get_cable_state(cable->edev, "USB-HOST");
+               if (ret)
+                       cable->state = false;
+               else
+                       cable->state = true;
+       }
+       return 0;
+}
+
+static int ci_extcon_register(struct ci_hdrc *ci)
+{
+       struct ci_hdrc_cable *id, *vbus;
+       int ret;
+
+       id = &ci->platdata->id_extcon;
+       id->ci = ci;
+       if (!IS_ERR(id->edev)) {
+               ret = extcon_register_interest(&id->conn, id->edev->name,
+                                                                                               "USB-HOST", &id->nb);
+               if (ret < 0) {
+                       dev_err(ci->dev, "register ID failed\n");
+                       return ret;
+               }
+       }
+
+       vbus = &ci->platdata->vbus_extcon;
+       vbus->ci = ci;
+       if (!IS_ERR(vbus->edev)) {
+               ret = extcon_register_interest(&vbus->conn, vbus->edev->name,
+                                                                                               "USB", &vbus->nb);
+               if (ret < 0) {
+                       extcon_unregister_interest(&id->conn);
+                       dev_err(ci->dev, "register VBUS failed\n");
+                       return ret;
+               }
+       }
+
        return 0;
 }

+static void ci_extcon_unregister(struct ci_hdrc *ci)
+{
+       struct ci_hdrc_cable *cable;
+
+       cable = &ci->platdata->id_extcon;
+       if (!IS_ERR(cable->edev))
+               extcon_unregister_interest(&cable->conn);
+
+       cable = &ci->platdata->vbus_extcon;
+       if (!IS_ERR(cable->edev))
+               extcon_unregister_interest(&cable->conn);
+}
+
 static DEFINE_IDA(ci_ida);

 struct platform_device *ci_hdrc_add_device(struct device *dev,

@@ -817,6 +936,10 @@ static int ci_hdrc_probe(struct platform_device *pdev)
        if (ret)
                goto stop;

+       ret = ci_extcon_register(ci);
+       if (ret)
+               goto stop;
+
        if (ci->supports_runtime_pm) {
                pm_runtime_set_active(&pdev->dev);
                pm_runtime_enable(&pdev->dev);

@@ -834,6 +957,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
        if (!ret)
                return 0;

There is dbg_create_files between these code which may also fail.

quoted

quoted

+       ci_extcon_unregister(ci);
 stop:
        ci_role_destroy(ci);
 deinit_phy:

@@ -853,6 +977,7 @@ static int ci_hdrc_remove(struct platform_device *pdev)
        }

        dbg_remove_files(ci);
+       ci_extcon_unregister(ci);
        ci_role_destroy(ci);
        ci_hdrc_enter_lpm(ci, true);
        ci_usb_phy_exit(ci);

diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c
index ad6c87a..77fe2df 100644
--- a/drivers/usb/chipidea/otg.c
+++ b/drivers/usb/chipidea/otg.c

@@ -30,7 +30,41 @@
  */
 u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
 {
-       return hw_read(ci, OP_OTGSC, mask);
+       struct ci_hdrc_cable *cable;
+       u32 val = hw_read(ci, OP_OTGSC, mask);
+
+       /*
+               * If using extcon framework for VBUS and/or ID signal
+               * detection overwrite OTGSC resiter value
+               */

%s/resiter/register

quoted

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+       cable = &ci->platdata->vbus_extcon;
+       if (!IS_ERR(cable->edev)) {
+               if (cable->changed)
+                       val |= OTGSC_BSVIS;
+               else
+                       val &= ~OTGSC_BSVIS;
+
+               if (cable->state)
+                       val |= OTGSC_BSV;
+               else
+                       val &= ~OTGSC_BSV;
+       }

You can clear cable->changed after that, then no change for hw_write_otgsc
is needed.

quoted

quoted

+
+       cable = &ci->platdata->id_extcon;
+       if (!IS_ERR(cable->edev)) {
+               if (cable->changed)
+                       val |= OTGSC_IDIS;
+               else
+                       val &= ~OTGSC_IDIS;
+
+               if (cable->state)
+                       val |= OTGSC_ID;
+               else
+                       val &= ~OTGSC_ID;
+       }
+
+       val &= mask;

It seems you do not need to do &mask again.

quoted

quoted

+       return val;
 }

 /**

@@ -40,7 +74,24 @@ u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
  */
 void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
 {
-       hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data);
+       struct ci_hdrc_cable *cable;
+
+       mask |= OTGSC_INT_STATUS_BITS;
+
+       /* clear artificial bits */
+       cable = &ci->platdata->vbus_extcon;
+       if (!IS_ERR(cable->edev)) {
+               if (data & OTGSC_BSVIS)
+                       cable->changed = false;
+       }
+
+       cable = &ci->platdata->id_extcon;
+       if (!IS_ERR(cable->edev)) {
+               if (data & OTGSC_IDIS)
+                       cable->changed = false;
+       }
+
+       hw_write(ci, OP_OTGSC, mask, data);
 }

 /**

diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
index ab94f78..05915cb1 100644
--- a/include/linux/usb/chipidea.h
+++ b/include/linux/usb/chipidea.h

@@ -5,9 +5,29 @@
 #ifndef __LINUX_USB_CHIPIDEA_H
 #define __LINUX_USB_CHIPIDEA_H

+#include <linux/extcon.h>
 #include <linux/usb/otg.h>

 struct ci_hdrc;
+
+/**
+ * struct ci_hdrc_cable - structure for external connector cable state tracking
+ * @state: current state of the line
+ * @changed: set to true when extcon event happen
+ * @edev: device which generate events
+ * @ci: driver state of the chipidea device
+ * @nb: hold event notification callback
+ * @conn: used for notification registration
+ */
+struct ci_hdrc_cable {
+       bool    state;
+       bool    changed;
+       struct extcon_dev*edev;
+       struct ci_hdrc*ci;
+       struct notifier_blocknb;
+       struct extcon_specific_cable_nb conn;
+};
+
 struct ci_hdrc_platform_data {
        const char*name;
        /* offset of the capability registers */

@@ -35,6 +55,10 @@ struct ci_hdrc_platform_data {
        void    (*notify_event) (struct ci_hdrc *ci, unsigned event);
        struct regulator*reg_vbus;
        bool    tpl_support;
+
+       /* VBUS and ID signal state tracking, using extcon framework */
+       struct ci_hdrc_cablevbus_extcon;
+       struct ci_hdrc_cableid_extcon;
 };

 /* Default offset of capability registers */
--

1.9.1

-- 

Best Regards,
Peter Chen
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