usb: chipidea: add flag CI_HDRC_DUAL_ROLE_NOT_OTG

Since we need otgsc to know vbus's status at some chipidea
controllers even it is peripheral-only mode. Besides, some
SoCs (eg, AR9331 SoC) don't have otgsc register even
the DCCPARAMS_DC and DCCPARAMS_HC are both 1 at CAP_DCCPARAMS.

We inroduce flag CI_HDRC_DUAL_ROLE_NOT_OTG to indicate if the
controller is dual role, but not supports OTG. If this flag is
not set, we follow the rule that if DCCPARAMS_DC and DCCPARAMS_HC
are both 1 at CAP_DCCPARAMS, then this controller is otg capable.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 35 insertions, 7 deletions

diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 75afc524b659..ab01e18bc2f8 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -426,6 +426,18 @@ static inline void ci_role_destroy(struct ci_hdrc *ci)
         ci_hdrc_host_destroy(ci);
 }
 
+static void ci_get_otg_capable(struct ci_hdrc *ci)
+{
+        if (ci->platdata->flags & CI_HDRC_DUAL_ROLE_NOT_OTG)
+                ci->is_otg = false;
+        else
+                ci->is_otg = (hw_read(ci, CAP_DCCPARAMS,
+                                DCCPARAMS_DC | DCCPARAMS_HC)
+                                        == (DCCPARAMS_DC | DCCPARAMS_HC));
+        if (ci->is_otg)
+                dev_dbg(ci->dev, "It is OTG capable controller\n");
+}
+
 static int ci_hdrc_probe(struct platform_device *pdev)
 {
         struct device   *dev = &pdev->dev;
@@ -480,6 +492,8 @@ static int ci_hdrc_probe(struct platform_device *pdev)
                 return -ENODEV;
         }
 
+        ci_get_otg_capable(ci);
+
         if (!ci->platdata->phy_mode)
                 ci->platdata->phy_mode = of_usb_get_phy_mode(of_node);
 
@@ -512,10 +526,22 @@ static int ci_hdrc_probe(struct platform_device *pdev)
         }
 
         if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
-                ci->is_otg = true;
-                /* ID pin needs 1ms debouce time, we delay 2ms for safe */
-                mdelay(2);
-                ci->role = ci_otg_role(ci);
+                if (ci->is_otg) {
+                        /*
+                         * ID pin needs 1ms debouce time,
+                         * we delay 2ms for safe.
+                         */
+                        mdelay(2);
+                        ci->role = ci_otg_role(ci);
+                        ci_hdrc_otg_init(ci);
+                } else {
+                        /*
+                         * If the controller is not OTG capable, but support
+                         * role switch, the defalt role is gadget, and the
+                         * user can switch it through debugfs.
+                         */
+                        ci->role = CI_ROLE_GADGET;
+                }
         } else {
                 ci->role = ci->roles[CI_ROLE_HOST]
                         ? CI_ROLE_HOST
@@ -534,9 +560,6 @@ static int ci_hdrc_probe(struct platform_device *pdev)
         if (ret)
                 goto stop;
 
-        if (ci->is_otg)
-                ci_hdrc_otg_init(ci);
-
         ret = dbg_create_files(ci);
         if (!ret)
                 return 0;
diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
index ce4e1aa071b3..10a607ce9090 100644
--- a/include/linux/usb/chipidea.h
+++ b/include/linux/usb/chipidea.h
@@ -20,6 +20,11 @@ struct ci_hdrc_platform_data {
 #define CI_HDRC_REQUIRE_TRANSCEIVER     BIT(1)
 #define CI_HDRC_PULLUP_ON_VBUS          BIT(2)
 #define CI_HDRC_DISABLE_STREAMING       BIT(3)
+        /*
+         * Only set it when DCCPARAMS.DC==1 and DCCPARAMS.HC==1,
+         * but otg is not supported (no register otgsc).
+         */
+#define CI_HDRC_DUAL_ROLE_NOT_OTG       BIT(4)
         enum usb_dr_mode        dr_mode;
 #define CI_HDRC_CONTROLLER_RESET_EVENT          0
 #define CI_HDRC_CONTROLLER_STOPPED_EVENT        1