USB: imx21-hcd accept arbitary transfer buffer alignement.

The hardware can only do DMA to 4 byte aligned addresses.
When this requirement is not met use PIO or a bounce buffer.

PIO is used when the buffer is small enough to directly
use the hardware data memory (2*maxpacket).

A bounce buffer is used for larger transfers.

Signed-off-by: Martin Fuzzey <mfuzzey@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/usb/host/imx21-hcd.h b/drivers/usb/host/imx21-hcd.h
index 1b0d913780a5..87b29fd971b4 100644
--- a/drivers/usb/host/imx21-hcd.h
+++ b/drivers/usb/host/imx21-hcd.h
@@ -250,6 +250,7 @@
 #define USBCTRL_USB_BYP                 (1 << 2)
 #define USBCTRL_HOST1_TXEN_OE           (1 << 1)
 
+#define USBOTG_DMEM             0x1000
 
 /* Values in TD blocks */
 #define TD_DIR_SETUP        0
@@ -346,8 +347,8 @@ struct td {
         struct list_head list;
         struct urb *urb;
         struct usb_host_endpoint *ep;
-        dma_addr_t data;
-        unsigned long buf_addr;
+        dma_addr_t dma_handle;
+        void *cpu_buffer;
         int len;
         int frame;
         int isoc_index;
@@ -360,6 +361,8 @@ struct etd_priv {
         struct td *td;
         struct list_head queue;
         dma_addr_t dma_handle;
+        void *cpu_buffer;
+        void *bounce_buffer;
         int alloc;
         int len;
         int dmem_size;
@@ -412,6 +415,7 @@ struct debug_isoc_trace {
 struct imx21 {
         spinlock_t lock;
         struct device *dev;
+        struct usb_hcd *hcd;
         struct mx21_usbh_platform_data *pdata;
         struct list_head dmem_list;
         struct list_head queue_for_etd; /* eps queued due to etd shortage */