usb: musb: dsps: Add the sw_babble_control() and Enable for newer silicon

Add sw_babble_control() logic to differentiate between transient
babble and real babble condition. Also add the SW babble control
register definitions.

Babble control register logic is implemented in the latest
revision of AM335x.

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@ti.com>
Tested-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/musb/musb_regs.h

@@ -72,6 +72,12 @@
 #define MUSB_DEVCTL_HR		0x02
 #define MUSB_DEVCTL_SESSION	0x01
 
+/* BABBLE_CTL */
+#define MUSB_BABBLE_FORCE_TXIDLE	0x80
+#define MUSB_BABBLE_SW_SESSION_CTRL	0x40
+#define MUSB_BABBLE_STUCK_J		0x20
+#define MUSB_BABBLE_RCV_DISABLE		0x04
+
 /* MUSB ULPI VBUSCONTROL */
 #define MUSB_ULPI_USE_EXTVBUS	0x01
 #define MUSB_ULPI_USE_EXTVBUSIND 0x02
@@ -246,6 +252,7 @@
  */
 
 #define MUSB_DEVCTL		0x60	/* 8 bit */
+#define MUSB_BABBLE_CTL		0x61	/* 8 bit */
 
 /* These are always controlled through the INDEX register */
 #define MUSB_TXFIFOSZ		0x62	/* 8-bit (see masks) */