musb: am35x: Workaround for fifo read issue
AM35x supports only 32bit read operations so we need to have
workaround for 8bit and 16bit read operations.
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
diff --git a/drivers/usb/musb/am35x.c b/drivers/usb/musb/am35x.c
index 2024940..1706c13 100644
--- a/drivers/usb/musb/am35x.c
+++ b/drivers/usb/musb/am35x.c
@@ -116,3 +116,35 @@
/* Turn off the phy */
phy_off();
}
+
+/*
+ * This function reads data from endpoint fifo for AM35x
+ * which supports only 32bit read operation.
+ *
+ * ep - endpoint number
+ * length - number of bytes to read from FIFO
+ * fifo_data - pointer to data buffer into which data is read
+ */
+__attribute__((weak))
+void read_fifo(u8 ep, u32 length, void *fifo_data)
+{
+ u8 *data = (u8 *)fifo_data;
+ u32 val;
+ int i;
+
+ /* select the endpoint index */
+ writeb(ep, &musbr->index);
+
+ if (length > 4) {
+ for (i = 0; i < (length >> 2); i++) {
+ val = readl(&musbr->fifox[ep]);
+ memcpy(data, &val, 4);
+ data += 4;
+ }
+ length %= 4;
+ }
+ if (length > 0) {
+ val = readl(&musbr->fifox[ep]);
+ memcpy(data, &val, length);
+ }
+}
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index dc740cf..6fe2c39 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -142,6 +142,11 @@
}
/*
+ * AM35x supports only 32bit read operations so
+ * use seperate read_fifo() function for it.
+ */
+#ifndef CONFIG_USB_AM35X
+/*
* This function reads data from endpoint fifo
*
* ep - endpoint number
@@ -160,3 +165,4 @@
while (length--)
*data++ = readb(&musbr->fifox[ep]);
}
+#endif /* CONFIG_USB_AM35X */