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serial: Refactor slightly to improve throughput

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It's unclear whether this refactor improves things at all, but it's
still limited to 32-byte buffers.  Still, it results in less code,
which seems like a good thing.

Signed-off-by: Sean Cross <xobs@kosagi.com>
This commit is contained in:
Sean Cross 2015-02-05 15:50:28 +08:00
parent 977ccff309
commit 9759e98747
1 changed files with 34 additions and 45 deletions
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79
serial.c
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@ -166,18 +166,10 @@ static int send_cur = 0;
#define USB_MODE_OUT 0 #define USB_MODE_OUT 0
#define USB_MODE_IN 1 #define USB_MODE_IN 1
static void usb_flush_output(void)
{
writeb(USB_CTRL_EP_INCSR1_INPKTRDY, USB_CTRL_EP_INCSR1);
/* Wait for the character to transmit, so we don't double-xmit */
while (!readb(USB_CTRL_INTRIN))
asm("");
send_cur = 0;
}
static void usb_set_mode(uint8_t epnum, int in) static void usb_set_mode(uint8_t epnum, int in)
{ {
writeb(epnum, USB_CTRL_INDEX);
if (in) { if (in) {
if (readb(USB_CTRL_EP_INCSR2) & USB_CTRL_EP_INCSR2_MODE) if (readb(USB_CTRL_EP_INCSR2) & USB_CTRL_EP_INCSR2_MODE)
/* Already set to "IN" */ /* Already set to "IN" */
@ -196,6 +188,24 @@ static void usb_set_mode(uint8_t epnum, int in)
} }
} }
static void usb_flush_output(int epnum)
{
/* Set endpoint to IN */
usb_set_mode(epnum, USB_MODE_IN);
/* Begin transmitting the packet */
writeb(USB_CTRL_EP_INCSR1_INPKTRDY, USB_CTRL_EP_INCSR1);
/* Wait for the character to transmit, so we don't double-xmit */
while (!readb(USB_CTRL_INTRIN))
asm("");
/* Set endpoint back to OUT */
usb_set_mode(epnum, USB_MODE_OUT);
send_cur = 0;
}
static void usb_receive_wait(uint8_t epnum) static void usb_receive_wait(uint8_t epnum)
{ {
uint32_t fifo_register = USB_CTRL_EP0_FIFO_DB0 + (epnum * 4); uint32_t fifo_register = USB_CTRL_EP0_FIFO_DB0 + (epnum * 4);
@ -207,37 +217,34 @@ static void usb_receive_wait(uint8_t epnum)
/* Select EP1 */ /* Select EP1 */
writeb(epnum, USB_CTRL_INDEX); writeb(epnum, USB_CTRL_INDEX);
/* Set endpoint to OUT */
usb_set_mode(epnum, USB_MODE_OUT);
while (!(readb(USB_CTRL_EP_OUTCSR1) & USB_CTRL_EP_OUTCSR1_RXPKTRDY)) while (!(readb(USB_CTRL_EP_OUTCSR1) & USB_CTRL_EP_OUTCSR1_RXPKTRDY))
asm(""); asm("");
recv_size = (readb(USB_CTRL_EP_COUNT1) << 0) & 0x00ff; recv_size = (readb(USB_CTRL_EP_COUNT1) << 0) & 0x00ff;
recv_size |= (readb(USB_CTRL_EP_COUNT2) << 8) & 0x0300; recv_size |= (readb(USB_CTRL_EP_COUNT2) << 8) & 0x0300;
recv_offset = 0;
int bytes_to_read = recv_size + 1; int bytes_to_read = recv_size + 1;
recv_offset = 0; int off = 0;
/* Fill in the receive buffer */ /* Fill in the receive buffer */
while (bytes_to_read) { while (bytes_to_read) {
if (bytes_to_read >= 4) { if (bytes_to_read >= 4) {
*((uint32_t *)(recv_bfr + recv_offset)) = readl(fifo_register); *((uint32_t *)(recv_bfr + off)) = readl(fifo_register);
bytes_to_read -= 4; bytes_to_read -= 4;
recv_offset += 4; off += 4;
} }
else if (bytes_to_read >= 2) { else if (bytes_to_read >= 2) {
*((uint16_t *)(recv_bfr + recv_offset)) = readw(fifo_register); *((uint16_t *)(recv_bfr + off)) = readw(fifo_register);
bytes_to_read -= 2; bytes_to_read -= 2;
recv_offset += 2; off += 2;
} }
else { else {
*((uint8_t *)(recv_bfr + recv_offset)) = readb(fifo_register); *((uint8_t *)(recv_bfr + off)) = readb(fifo_register);
bytes_to_read -= 1; bytes_to_read -= 1;
recv_offset += 1; off += 1;
} }
} }
recv_offset = 0;
/* Clear FIFO (write 0 to RXPKTRDY) */ /* Clear FIFO (write 0 to RXPKTRDY) */
writeb(0, USB_CTRL_EP_OUTCSR1); writeb(0, USB_CTRL_EP_OUTCSR1);
@ -251,44 +258,23 @@ static void usb_handle_irqs(int epnum)
/* Select EP1 */ /* Select EP1 */
writeb(epnum, USB_CTRL_INDEX); writeb(epnum, USB_CTRL_INDEX);
/* Set endpoint to IN */ /* If data exists in the output FIFOs, send the packet */
usb_set_mode(epnum, USB_MODE_IN);
if (send_cur) if (send_cur)
usb_flush_output(); usb_flush_output(epnum);
/* Flush the output FIFO if there is data present */
// while (readb(USB_CTRL_EP_INCSR1) & USB_CTRL_EP_INCSR1_FIFONOTEMPTY)
// writeb(USB_CTRL_EP_INCSR1_INPKTRDY, USB_CTRL_EP_INCSR1);
/* Set endpoint to OUT */
usb_set_mode(epnum, USB_MODE_OUT);
/* If there are incoming bytes, read them into the buffer */ /* If there are incoming bytes, read them into the buffer */
if (readb(USB_CTRL_EP_OUTCSR1) & USB_CTRL_EP_OUTCSR1_RXPKTRDY) if (readb(USB_CTRL_EP_OUTCSR1) & USB_CTRL_EP_OUTCSR1_RXPKTRDY)
usb_receive_wait(epnum); usb_receive_wait(epnum);
/* Set endpoint back to IN to await incoming packets */
usb_set_mode(epnum, USB_MODE_IN);
} }
int serial_putc(uint8_t c) int serial_putc(uint8_t c)
{ {
#if 0
/* Wait for the bus to be idle, so we don't double-xmit */
while (readb(USB_CTRL_INTRIN))
asm("");
#endif
/* Select EP1 */
// writeb(1, USB_CTRL_INDEX);
/* Add the character to the FIFO */ /* Add the character to the FIFO */
writeb(c, USB_CTRL_EP1_FIFO_DB0); writeb(c, USB_CTRL_EP1_FIFO_DB0);
send_cur++; send_cur++;
if (send_cur >= send_max) if (send_cur >= send_max)
usb_flush_output(); usb_flush_output(1);
return 0; return 0;
} }
@ -373,6 +359,9 @@ void serial_init(void)
//writeb(USB_CTRL_EP_INCSR2_AUTOSET, USB_CTRL_EP_INCSR2); //writeb(USB_CTRL_EP_INCSR2_AUTOSET, USB_CTRL_EP_INCSR2);
writeb(0, USB_CTRL_EP_INCSR2); writeb(0, USB_CTRL_EP_INCSR2);
/* Set the USB mode to OUT, to ensure we receive packets from host */
usb_set_mode(1, USB_MODE_OUT);
recv_offset = 0; recv_offset = 0;
recv_size = 0; recv_size = 0;
usb_handle_irqs(1); usb_handle_irqs(1);