Pandora Sourcecodes - openembedded.git/blob

   1 From 4288b7df4ae6629a4fb14aca2c489da01d4d19c3 Mon Sep 17 00:00:00 2001
   2 From: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
   3 Date: Tue, 31 Mar 2009 12:35:09 -0700
   4 Subject: [PATCH] musb: support disconnect after HNP roleswitch
   5
   6 Adjust HNP state machines in MUSB driver so that they handle the
   7 case where the cable is disconnected.  The A-side machine was
   8 very wrong (unrecoverable); the B-Side was much less so.
   9
  10  - A_PERIPHERAL ... as usual, the non-observability of the ID
  11    pin through Mentor's registers makes trouble.  We can't go
  12    directly to A_WAIT_VFALL to end the session and start the
  13    disconnect processing.  We can however sense link suspending,
  14    go to A_WAIT_BCON, and from there use OTG timeouts to finally
  15    trigger that A_WAIT_VFALL transition.  (Hoping that nobody
  16    reconnects quickly to that port and notices the wrong state.)
  17
  18  - B_HOST ... actually clear the Host Request (HR) bit as the
  19    messages say, disconnect the peripheral from the root hub,
  20    and don't detour through a suspend state.  (In some cases
  21    this would eventually have cleaned up.)
  22
  23 Also adjust the A_SUSPEND transition to respect the A_AIDL_BDIS
  24 timeout, so if HNP doesn't trigger quickly enough the A_WAIT_VFALL
  25 transition happens as it should.
  26
  27 Signed-off-by: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
  28 ---
  29  drivers/usb/musb/musb_core.c    |   41 +++++++++++++++++++++++++++-----------
  30  drivers/usb/musb/musb_gadget.c  |    2 +
  31  drivers/usb/musb/musb_virthub.c |    4 +++
  32  3 files changed, 35 insertions(+), 12 deletions(-)
  33
  34 diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
  35 index 9dc995a..5770ccb 100644
  36 --- a/drivers/usb/musb/musb_core.c
  37 +++ b/drivers/usb/musb/musb_core.c
  38 @@ -304,9 +304,11 @@ void musb_otg_timer_func(unsigned long data)
  39                 musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
  40                 musb->is_active = 0;
  41                 break;
  42 +       case OTG_STATE_A_SUSPEND:
  43         case OTG_STATE_A_WAIT_BCON:
  44 -               DBG(1, "HNP: a_wait_bcon timeout; back to a_host\n");
  45 -               musb_hnp_stop(musb);
  46 +               DBG(1, "HNP: %s timeout\n", otg_state_string(musb));
  47 +               musb_set_vbus(musb, 0);
  48 +               musb->xceiv->state = OTG_STATE_A_WAIT_VFALL;
  49                 break;
  50         default:
  51                 DBG(1, "HNP: Unhandled mode %s\n", otg_state_string(musb));
  52 @@ -324,15 +326,12 @@ void musb_hnp_stop(struct musb *musb)
  53         void __iomem    *mbase = musb->mregs;
  54         u8      reg;
  55
  56 +       DBG(1, "HNP: stop from %s\n", otg_state_string(musb));
  57 +
  58         switch (musb->xceiv->state) {
  59         case OTG_STATE_A_PERIPHERAL:
  60 -       case OTG_STATE_A_WAIT_VFALL:
  61 -       case OTG_STATE_A_WAIT_BCON:
  62 -               DBG(1, "HNP: Switching back to A-host\n");
  63                 musb_g_disconnect(musb);
  64 -               musb->xceiv->state = OTG_STATE_A_IDLE;
  65 -               MUSB_HST_MODE(musb);
  66 -               musb->is_active = 0;
  67 +               DBG(1, "HNP: back to %s\n", otg_state_string(musb));
  68                 break;
  69         case OTG_STATE_B_HOST:
  70                 DBG(1, "HNP: Disabling HR\n");
  71 @@ -775,7 +774,16 @@ static irqreturn_t musb_stage2_irq(struct musb *musb, u8 int_usb,
  72  #endif /* HOST */
  73  #ifdef CONFIG_USB_MUSB_OTG
  74                 case OTG_STATE_B_HOST:
  75 -                       musb_hnp_stop(musb);
  76 +                       /* REVISIT this behaves for "real disconnect"
  77 +                        * cases; make sure the other transitions from
  78 +                        * from B_HOST act right too.  The B_HOST code
  79 +                        * in hnp_stop() is currently not used...
  80 +                        */
  81 +                       musb_root_disconnect(musb);
  82 +                       musb_to_hcd(musb)->self.is_b_host = 0;
  83 +                       musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
  84 +                       MUSB_DEV_MODE(musb);
  85 +                       musb_g_disconnect(musb);
  86                         break;
  87                 case OTG_STATE_A_PERIPHERAL:
  88                         musb_hnp_stop(musb);
  89 @@ -807,10 +815,19 @@ static irqreturn_t musb_stage2_irq(struct musb *musb, u8 int_usb,
  90                 switch (musb->xceiv->state) {
  91  #ifdef CONFIG_USB_MUSB_OTG
  92                 case OTG_STATE_A_PERIPHERAL:
  93 -                       /*
  94 -                        * We cannot stop HNP here, devctl BDEVICE might be
  95 -                        * still set.
  96 +                       /* We also come here if the cable is removed, since
  97 +                        * this silicon doesn't report ID-no-longer-grounded.
  98 +                        *
  99 +                        * We depend on T(a_wait_bcon) to shut us down, and
 100 +                        * hope users don't do anything dicey during this
 101 +                        * undesired detour through A_WAIT_BCON.
 102                          */
 103 +                       musb_hnp_stop(musb);
 104 +                       usb_hcd_resume_root_hub(musb_to_hcd(musb));
 105 +                       musb_root_disconnect(musb);
 106 +                       musb_platform_try_idle(musb, jiffies
 107 +                                       + msecs_to_jiffies(musb->a_wait_bcon
 108 +                                               ? : OTG_TIME_A_WAIT_BCON));
 109                         break;
 110  #endif
 111                 case OTG_STATE_B_PERIPHERAL:
 112 diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
 113 index 7dd3d59..8b3c4e2 100644
 114 --- a/drivers/usb/musb/musb_gadget.c
 115 +++ b/drivers/usb/musb/musb_gadget.c
 116 @@ -1962,9 +1962,11 @@ void musb_g_disconnect(struct musb *musb)
 117                 DBG(2, "Unhandled disconnect %s, setting a_idle\n",
 118                         otg_state_string(musb));
 119                 musb->xceiv->state = OTG_STATE_A_IDLE;
 120 +               MUSB_HST_MODE(musb);
 121                 break;
 122         case OTG_STATE_A_PERIPHERAL:
 123                 musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
 124 +               MUSB_HST_MODE(musb);
 125                 break;
 126         case OTG_STATE_B_WAIT_ACON:
 127         case OTG_STATE_B_HOST:
 128 diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c
 129 index 14f7cf3..e8ef925 100644
 130 --- a/drivers/usb/musb/musb_virthub.c
 131 +++ b/drivers/usb/musb/musb_virthub.c
 132 @@ -83,6 +83,10 @@ static void musb_port_suspend(struct musb *musb, bool do_suspend)
 133                         musb->xceiv->state = OTG_STATE_A_SUSPEND;
 134                         musb->is_active = is_otg_enabled(musb)
 135                                         && musb->xceiv->host->b_hnp_enable;
 136 +                       if (musb->is_active)
 137 +                               mod_timer(&musb->otg_timer, jiffies
 138 +                                       + msecs_to_jiffies(
 139 +                                               OTG_TIME_A_AIDL_BDIS));
 140                         musb_platform_try_idle(musb, 0);
 141                         break;
 142  #ifdef CONFIG_USB_MUSB_OTG
 143 --
 144 1.6.0.4
 145