musb: Add support for dma fifo reads and performance tuning
Using dma for reading the fifo, and tightening the loop around
transfers, allows us to quadruple the data throughput or more.
Change-Id: I09c6c5fb85a6c2cc8216c09066479370307dcd42
Signed-off-by: Mike J. Chen <mjchen@google.com>
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index a8adcce..766c30c 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -145,6 +145,19 @@
struct musb_epN_regs epN;
} ep[16];
+ u8 hsdma_intr; /* 0x200 */
+ u8 reserved4[3];
+ u16 hsdma_control_1; /* 0x204 */
+ u16 hsdma_reserved_1_1; /* 0x206 */
+ u32 hsdma_address_1; /* 0x208 */
+ u32 hsdma_count_1; /* 0x20C */
+
+ u32 hsdma_reserved2_0; /* 0x210 */
+ u16 hsdma_control_2; /* 0x214 */
+ u16 hsdma_reserved2_1; /* 0x216 */
+ u32 hsdma_address_2; /* 0x218 */
+ u32 hsdma_count_2; /* 0x21C */
+
} __attribute__((packed, aligned(32)));
#endif
@@ -329,6 +342,20 @@
/* HUBADDR */
#define MUSB_HUBADDR_MULTI_TT 0x80
+/* DMA Control */
+#define MUSB_DMA_CNTL_BURST_MODE_0 0x0000
+#define MUSB_DMA_CNTL_BURST_MODE_1 0x0200
+#define MUSB_DMA_CNTL_BURST_MODE_2 0x0400
+#define MUSB_DMA_CNTL_BURST_MODE_3 0x0600
+#define MUSB_DMA_CNTL_ERR 0x0100
+#define MUSB_DMA_CNTL_END_POINT(n) ((n)<<4)
+#define MUSB_DMA_CNTL_INTERRUPT_ENABLE 0x0008
+#define MUSB_DMA_CNTL_MODE_0 0x0000
+#define MUSB_DMA_CNTL_MODE_1 0x0004
+#define MUSB_DMA_CNTL_WRITE 0x0000
+#define MUSB_DMA_CNTL_READ 0x0002
+#define MUSB_DMA_CNTL_ENABLE 0x0001
+
/* Endpoint configuration information. Note: The value of endpoint fifo size
* element should be either 8,16,32,64,128,256,512,1024,2048 or 4096. Other
* values are not supported
diff --git a/drivers/usb/musb/musb_udc.c b/drivers/usb/musb/musb_udc.c
index 6efa198..9e1c318 100644
--- a/drivers/usb/musb/musb_udc.c
+++ b/drivers/usb/musb/musb_udc.c
@@ -551,8 +551,7 @@
else
length = count0;
- data = (u8 *) urb->buffer_data;
- data += urb->actual_length;
+ data = urb->buffer + urb->actual_length;
/* The common musb fifo reader */
read_fifo(0, length, data);
@@ -680,61 +679,140 @@
musb_peri_ep0_rx();
}
+/* to make compatiblity easier, we dma to a fixed buffer and
+ * memcpy it out. otherwise, the buffer we're given might not
+ * be cache aligned. buffer must be word aligned, but we make
+ * it aligned even bigger to make it cache aligned on most systems.
+ *
+ * we only read from the dma_buffer and never write to it, so it's
+ * safe to only invalidate the range after the dma is done and
+ * before we memcpy to the receive buffer. if this ever changes,
+ * we may have to do more to make sure the cache doesn't flush
+ * itself asynchronously after we've done the dma but before
+ * we've done the invalidate, and corrupt our data.
+ */
+static u8 dma_buffer[1024] __attribute__ ((aligned(0x100)));
+
+static int read_fifo_dma(unsigned int ep, u32 count, u8 *buf)
+{
+ int rc = -1;
+ u16 peri_rxcsr;
+ u16 dma_control;
+
+ if (count > sizeof(dma_buffer)) {
+ serial_printf("count %d > sizeof(dma_buffer) %d\n",
+ count, sizeof(dma_buffer));
+ return rc;
+ }
+
+ peri_rxcsr = readw(&musbr->ep[ep].epN.rxcsr);
+ peri_rxcsr &= ~MUSB_RXCSR_AUTOCLEAR;
+ peri_rxcsr |= MUSB_RXCSR_DMAENAB;
+ writew(peri_rxcsr, &musbr->ep[ep].epN.rxcsr);
+
+ /* hard coded for dma channel 1 for now */
+
+ /* stop any previous transfer */
+ writeb(0, &musbr->hsdma_control_1);
+
+ /* set the address */
+ writel((u32)dma_buffer, &musbr->hsdma_address_1);
+ /* set the transfer size */
+ writel(count, &musbr->hsdma_count_1);
+
+ /* set the control parts. we already checked that
+ * the size is a multiple of 16 so we can use
+ * burst mode of 16 bytes.
+ */
+ dma_control = (MUSB_DMA_CNTL_BURST_MODE_3 |
+ MUSB_DMA_CNTL_END_POINT(ep) |
+ MUSB_DMA_CNTL_WRITE |
+ MUSB_DMA_CNTL_ENABLE);
+ writew(dma_control, &musbr->hsdma_control_1);
+
+ while (1) {
+ if (readw(&musbr->hsdma_control_1) & MUSB_DMA_CNTL_ERR) {
+ serial_printf("dma error\n");
+ break;
+ }
+ if (readl(&musbr->hsdma_count_1) == 0) {
+ rc = 0;
+ break;
+ }
+ }
+
+ /* clear DMAENAB and DMAMODE and do the rx_ack */
+ peri_rxcsr &= ~(MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAENAB |
+ MUSB_RXCSR_RXPKTRDY);
+ writew(peri_rxcsr, &musbr->ep[ep].epN.rxcsr);
+
+ if (rc == 0) {
+ invalidate_dcache_range((u32)dma_buffer,
+ (u32)dma_buffer + sizeof(dma_buffer));
+ memcpy(buf, dma_buffer, count);
+ }
+ return rc;
+}
+
static void musb_peri_rx_ep(unsigned int ep)
{
- u16 peri_rxcount = readw(&musbr->ep[ep].epN.rxcount);
+ struct usb_endpoint_instance *endpoint;
+ struct urb *urb;
- if (peri_rxcount) {
- struct usb_endpoint_instance *endpoint;
- u32 length;
- u8 *data;
+ if (!(readw(&musbr->ep[ep].epN.rxcsr) & MUSB_RXCSR_RXPKTRDY))
+ return;
- endpoint = GET_ENDPOINT(udc_device, ep);
- if (endpoint && endpoint->rcv_urb) {
- struct urb *urb = endpoint->rcv_urb;
- unsigned int remaining_space = urb->buffer_length -
- urb->actual_length;
+ endpoint = GET_ENDPOINT(udc_device, ep);
+ if (endpoint == NULL) {
+ if (debug_level > 0)
+ serial_printf("ERROR : %s %d problem with endpoint\n",
+ __PRETTY_FUNCTION__, ep);
+ return;
+ }
- if (remaining_space) {
- int urb_bad = 0; /* urb is good */
+ urb = endpoint->rcv_urb;
+ if (urb == NULL) {
+ if (debug_level > 0)
+ serial_printf("ERROR : %s %d problem with urb\n",
+ __PRETTY_FUNCTION__, ep);
+ return;
- if (peri_rxcount > remaining_space)
- length = remaining_space;
- else
- length = peri_rxcount;
+ }
- data = (u8 *) urb->buffer_data;
- data += urb->actual_length;
+ do {
+ u16 peri_rxcount = readw(&musbr->ep[ep].epN.rxcount);
+ unsigned int remaining_space;
+ if (peri_rxcount == 0)
+ return;
+ remaining_space = urb->buffer_length - urb->actual_length;
+ if (remaining_space) {
+ u8 *data = urb->buffer + urb->actual_length;
- /* The common musb fifo reader */
- read_fifo(ep, length, data);
+ if (peri_rxcount > remaining_space)
+ peri_rxcount = remaining_space;
+ /* The common musb fifo reader. Use dma
+ * read if length is a multiple of 16.
+ * Fallback to pio mode on any failure.
+ */
+ if ((peri_rxcount & 0xf) ||
+ (read_fifo_dma(ep, peri_rxcount, data))) {
+ read_fifo(ep, peri_rxcount, data);
musb_peri_rx_ack(ep);
-
- /*
- * urb's actual_length is updated in
- * usbd_rcv_complete
- */
- usbd_rcv_complete(endpoint, length, urb_bad);
-
- } else {
- if (debug_level > 0)
- serial_printf("ERROR : %s %d no space "
- "in rcv buffer\n",
- __PRETTY_FUNCTION__, ep);
}
+
+ /* urb's actual_length is updated in
+ * usbd_rcv_complete
+ */
+ usbd_rcv_complete(endpoint, peri_rxcount, 0);
+
} else {
if (debug_level > 0)
- serial_printf("ERROR : %s %d problem with "
- "endpoint\n",
+ serial_printf("ERROR : %s %d no space "
+ "in rcv buffer\n",
__PRETTY_FUNCTION__, ep);
}
-
- } else {
- if (debug_level > 0)
- serial_printf("ERROR : %s %d with nothing to do\n",
- __PRETTY_FUNCTION__, ep);
- }
+ } while (readw(&musbr->ep[ep].epN.rxcsr) & MUSB_RXCSR_RXPKTRDY);
}
static void musb_peri_rx(u16 intr)
@@ -901,8 +979,7 @@
else
length = remaining_packet;
- data = (u8 *) urb->buffer;
- data += endpoint->sent;
+ data = (u8 *) urb->buffer + endpoint->sent;
/* common musb fifo function */
write_fifo(ep, length, data);
