Find whether we are running on newer silicon. The babble control
register reads 0x4 by default in newer silicon as opposed to 0
in old versions of AM335x. Based on this enable the sw babble
control logic.
Signed-off-by: George Cherian <george.cherian@xxxxxx>
---
drivers/usb/musb/musb_dsps.c | 37 +++++++++++++++++++++++++++++++------
1 file changed, 31 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index eb1985a..8daccb2 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -136,6 +136,7 @@ struct dsps_glue {
const struct dsps_musb_wrapper *wrp; /* wrapper register offsets */
struct timer_list timer; /* otg_workaround timer */
unsigned long last_timer; /* last timer data for each instance */
+ bool sw_babble_enabled;
struct dsps_context context;
struct debugfs_regset32 regset;
@@ -469,6 +470,19 @@ static int dsps_musb_init(struct musb *musb)
val &= ~(1 << wrp->otg_disable);
dsps_writel(musb->ctrl_base, wrp->phy_utmi, val);
+ /*
+ * Check whether the dsps version has babble control enabled.
+ * In latest silicon revision the babble control logic is enabled.
+ * If MUSB_BABBLE_CTL returns 0x4 then we have the babble control
+ * logic enabled.
+ */
+ val = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
+ if (val == MUSB_BABBLE_RCV_DISABLE) {
+ glue->sw_babble_enabled = true;
+ val |= MUSB_BABBLE_SW_SESSION_CTRL;
+ dsps_writeb(musb->mregs, MUSB_BABBLE_CTL, val);
+ }
+
ret = dsps_musb_dbg_init(musb, glue);
if (ret)
return ret;
@@ -591,14 +605,25 @@ static int dsps_musb_reset(struct musb *musb)
struct device *dev = musb->controller;
struct dsps_glue *glue = dev_get_drvdata(dev->parent);
const struct dsps_musb_wrapper *wrp = glue->wrp;
+ int session_restart = 0;
- dsps_writel(musb->ctrl_base, wrp->control, (1 << wrp->reset));
- usleep_range(100, 200);
- usb_phy_shutdown(musb->xceiv);
- usleep_range(100, 200);
- usb_phy_init(musb->xceiv);
+ if (glue->sw_babble_enabled)
+ session_restart = sw_babble_control(musb);
+ /*
+ * In case of new silicon version babble condition can be recovered
+ * without resetting the MUSB. But for older silicon versions, MUSB
+ * reset is needed
+ */
+ if (session_restart || !glue->sw_babble_enabled) {
+ dsps_writel(musb->ctrl_base, wrp->control, (1 << wrp->reset));
+ usleep_range(100, 200);
+ usb_phy_shutdown(musb->xceiv);
+ usleep_range(100, 200);
+ usb_phy_init(musb->xceiv);
+ session_restart = 1;
+ }
- return 0;
+ return !session_restart;
}
static struct musb_platform_ops dsps_ops = {
--
1.8.3.1
--
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