phy: cpcap-usb: Improve host vs docked mode detection

When docked to a Motorola lapdock or media dock, we're in USB A-host mode
with VBUS provided by the dock. When in regular USB A-host mode, we're
providing the VBUS. And in regular USB A-host mode we must also keep
kicking the VBUS to keep it active.

Let's wait a bit before configuring the USB PHY to allow some time between
the ID and VBUS changes. And let's add vbus_provider flag so we can detect
docked mode and regularo USB A-host mode better.

With better USB A-host mode detection, we can now also just kick the
VBUS to keep it enabled and leave out the unnecessary line muxing.

We only need to set and clear vbus_provider in the delayed work so no
locking is needed for it currently.

Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

diff --git a/drivers/phy/motorola/phy-cpcap-usb.c b/drivers/phy/motorola/phy-cpcap-usb.c
index 5baf64dfb24de8408c1c2edfa34aedab20176079..da0b4eb8398deab4c27d07cda420f928d2d32830 100644 (file)
--- a/drivers/phy/motorola/phy-cpcap-usb.c
+++ b/drivers/phy/motorola/phy-cpcap-usb.c
@@ -134,6 +134,8 @@ struct cpcap_phy_ddata {
        struct iio_channel *id;
        struct regulator *vusb;
        atomic_t active;
+       unsigned int vbus_provider:1;
+       unsigned int docked:1;
 };
 
 static bool cpcap_usb_vbus_valid(struct cpcap_phy_ddata *ddata)
@@ -233,8 +235,60 @@ static void cpcap_usb_detect(struct work_struct *work)
        if (error)
                return;
 
-       if (s.id_ground) {
+       vbus = cpcap_usb_vbus_valid(ddata);
+
+       /* We need to kick the VBUS as USB A-host */
+       if (s.id_ground && ddata->vbus_provider) {
+               dev_dbg(ddata->dev, "still in USB A-host mode, kicking VBUS\n");
+
+               cpcap_usb_try_musb_mailbox(ddata, MUSB_ID_GROUND);
+
+               error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC3,
+                                          CPCAP_BIT_VBUSSTBY_EN |
+                                          CPCAP_BIT_VBUSEN_SPI,
+                                          CPCAP_BIT_VBUSEN_SPI);
+               if (error)
+                       goto out_err;
+
+               return;
+       }
+
+       if (vbus && s.id_ground && ddata->docked) {
+               dev_dbg(ddata->dev, "still docked as A-host, signal ID down\n");
+
+               cpcap_usb_try_musb_mailbox(ddata, MUSB_ID_GROUND);
+
+               return;
+       }
+
+       /* No VBUS needed with docks */
+       if (vbus && s.id_ground && !ddata->vbus_provider) {
+               dev_dbg(ddata->dev, "connected to a dock\n");
+
+               ddata->docked = true;
+
+               error = cpcap_usb_set_usb_mode(ddata);
+               if (error)
+                       goto out_err;
+
+               cpcap_usb_try_musb_mailbox(ddata, MUSB_ID_GROUND);
+
+               /*
+                * Force check state again after musb has reoriented,
+                * otherwise devices won't enumerate after loading PHY
+                * driver.
+                */
+               schedule_delayed_work(&ddata->detect_work,
+                                     msecs_to_jiffies(1000));
+
+               return;
+       }
+
+       if (s.id_ground && !ddata->docked) {
                dev_dbg(ddata->dev, "id ground, USB host mode\n");
+
+               ddata->vbus_provider = true;
+
                error = cpcap_usb_set_usb_mode(ddata);
                if (error)
                        goto out_err;
@@ -259,21 +313,8 @@ static void cpcap_usb_detect(struct work_struct *work)
 
        vbus = cpcap_usb_vbus_valid(ddata);
 
+       /* Otherwise assume we're connected to a USB host */
        if (vbus) {
-               /* Are we connected to a docking station with vbus? */
-               if (s.id_ground) {
-                       dev_dbg(ddata->dev, "connected to a dock\n");
-
-                       /* No VBUS needed with docks */
-                       error = cpcap_usb_set_usb_mode(ddata);
-                       if (error)
-                               goto out_err;
-                       cpcap_usb_try_musb_mailbox(ddata, MUSB_ID_GROUND);
-
-                       return;
-               }
-
-               /* Otherwise assume we're connected to a USB host */
                dev_dbg(ddata->dev, "connected to USB host\n");
                error = cpcap_usb_set_usb_mode(ddata);
                if (error)
@@ -283,6 +324,8 @@ static void cpcap_usb_detect(struct work_struct *work)
                return;
        }
 
+       ddata->vbus_provider = false;
+       ddata->docked = false;
        cpcap_usb_try_musb_mailbox(ddata, MUSB_VBUS_OFF);
 
        /* Default to debug UART mode */