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path: root/drivers/usb/musb/musb_dsps.c
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Diffstat (limited to 'drivers/usb/musb/musb_dsps.c')
-rw-r--r--drivers/usb/musb/musb_dsps.c113
1 files changed, 101 insertions, 12 deletions
diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index 51beb13c7e1a..c791ba5da91a 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -56,16 +56,24 @@ static const struct of_device_id musb_dsps_of_match[];
* dependent on musb core layer symbols.
*/
static inline u8 dsps_readb(const void __iomem *addr, unsigned offset)
- { return __raw_readb(addr + offset); }
+{
+ return __raw_readb(addr + offset);
+}
static inline u32 dsps_readl(const void __iomem *addr, unsigned offset)
- { return __raw_readl(addr + offset); }
+{
+ return __raw_readl(addr + offset);
+}
static inline void dsps_writeb(void __iomem *addr, unsigned offset, u8 data)
- { __raw_writeb(data, addr + offset); }
+{
+ __raw_writeb(data, addr + offset);
+}
static inline void dsps_writel(void __iomem *addr, unsigned offset, u32 data)
- { __raw_writel(data, addr + offset); }
+{
+ __raw_writel(data, addr + offset);
+}
/**
* DSPS musb wrapper register offset.
@@ -136,6 +144,7 @@ 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 +478,19 @@ 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;
@@ -494,10 +516,9 @@ static int dsps_musb_set_mode(struct musb *musb, u8 mode)
struct dsps_glue *glue = dev_get_drvdata(dev->parent);
const struct dsps_musb_wrapper *wrp = glue->wrp;
void __iomem *ctrl_base = musb->ctrl_base;
- void __iomem *base = musb->mregs;
u32 reg;
- reg = dsps_readl(base, wrp->mode);
+ reg = dsps_readl(ctrl_base, wrp->mode);
switch (mode) {
case MUSB_HOST:
@@ -510,7 +531,7 @@ static int dsps_musb_set_mode(struct musb *musb, u8 mode)
*/
reg |= (1 << wrp->iddig_mux);
- dsps_writel(base, wrp->mode, reg);
+ dsps_writel(ctrl_base, wrp->mode, reg);
dsps_writel(ctrl_base, wrp->phy_utmi, 0x02);
break;
case MUSB_PERIPHERAL:
@@ -523,10 +544,10 @@ static int dsps_musb_set_mode(struct musb *musb, u8 mode)
*/
reg |= (1 << wrp->iddig_mux);
- dsps_writel(base, wrp->mode, reg);
+ dsps_writel(ctrl_base, wrp->mode, reg);
break;
case MUSB_OTG:
- dsps_writel(base, wrp->phy_utmi, 0x02);
+ dsps_writel(ctrl_base, wrp->phy_utmi, 0x02);
break;
default:
dev_err(glue->dev, "unsupported mode %d\n", mode);
@@ -536,14 +557,82 @@ static int dsps_musb_set_mode(struct musb *musb, u8 mode)
return 0;
}
-static void dsps_musb_reset(struct musb *musb)
+static bool sw_babble_control(struct musb *musb)
+{
+ u8 babble_ctl;
+ bool session_restart = false;
+
+ babble_ctl = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
+ dev_dbg(musb->controller, "babble: MUSB_BABBLE_CTL value %x\n",
+ babble_ctl);
+ /*
+ * check line monitor flag to check whether babble is
+ * due to noise
+ */
+ dev_dbg(musb->controller, "STUCK_J is %s\n",
+ babble_ctl & MUSB_BABBLE_STUCK_J ? "set" : "reset");
+
+ if (babble_ctl & MUSB_BABBLE_STUCK_J) {
+ int timeout = 10;
+
+ /*
+ * babble is due to noise, then set transmit idle (d7 bit)
+ * to resume normal operation
+ */
+ babble_ctl = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
+ babble_ctl |= MUSB_BABBLE_FORCE_TXIDLE;
+ dsps_writeb(musb->mregs, MUSB_BABBLE_CTL, babble_ctl);
+
+ /* wait till line monitor flag cleared */
+ dev_dbg(musb->controller, "Set TXIDLE, wait J to clear\n");
+ do {
+ babble_ctl = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
+ udelay(1);
+ } while ((babble_ctl & MUSB_BABBLE_STUCK_J) && timeout--);
+
+ /* check whether stuck_at_j bit cleared */
+ if (babble_ctl & MUSB_BABBLE_STUCK_J) {
+ /*
+ * real babble condition has occurred
+ * restart the controller to start the
+ * session again
+ */
+ dev_dbg(musb->controller, "J not cleared, misc (%x)\n",
+ babble_ctl);
+ session_restart = true;
+ }
+ } else {
+ session_restart = true;
+ }
+
+ return session_restart;
+}
+
+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;
+
+ 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) {
+ dev_info(musb->controller, "Restarting MUSB to recover from Babble\n");
+ 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;
+ }
- dsps_writel(musb->ctrl_base, wrp->control, (1 << wrp->reset));
- udelay(100);
+ return !session_restart;
}
static struct musb_platform_ops dsps_ops = {