Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-15 07:33:56 +00:00
Code Issues Packages Projects Releases Wiki Activity

msm_serial: Send more than 1 character at a time on UARTDM

Browse Source 
UARTDM cores have a TX fifo that can accept more than one
character per register write, but the msm_serial driver currently
only supports 1 character mode. Add support for this mode of operation
to speed up the transmit path on DM devices.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Stephen Boyd 2013-07-24 11:37:31 -07:00 committed by Greg Kroah-Hartman
parent 6909dadd91
commit 17fae28efe
1 changed files with 32 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
drivers/tty/serial/msm_serial.c
View File

@ -195,10 +195,10 @@ static void handle_rx(struct uart_port *port)
tty_flip_buffer_push(tport);
}
static void reset_dm_count(struct uart_port *port)
static void reset_dm_count(struct uart_port *port, int count)
{
wait_for_xmitr(port);
msm_write(port, 1, UARTDM_NCF_TX);
msm_write(port, count, UARTDM_NCF_TX);
msm_read(port, UARTDM_NCF_TX);
}
@ -206,39 +206,52 @@ static void handle_tx(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
struct msm_port *msm_port = UART_TO_MSM(port);
int sent_tx;
unsigned int tx_count, num_chars;
unsigned int tf_pointer = 0;
tx_count = uart_circ_chars_pending(xmit);
tx_count = min3(tx_count, (unsigned int)UART_XMIT_SIZE - xmit->tail,
port->fifosize);
if (port->x_char) {
if (msm_port->is_uartdm)
reset_dm_count(port);
reset_dm_count(port, tx_count + 1);
msm_write(port, port->x_char,
msm_port->is_uartdm ? UARTDM_TF : UART_TF);
port->icount.tx++;
port->x_char = 0;
} else if (tx_count && msm_port->is_uartdm) {
reset_dm_count(port, tx_count);
}
if (msm_port->is_uartdm)
reset_dm_count(port);
while (tf_pointer < tx_count) {
int i;
char buf[4] = { 0 };
unsigned int *bf = (unsigned int *)&buf;
while (msm_read(port, UART_SR) & UART_SR_TX_READY) {
if (uart_circ_empty(xmit)) {
/* disable tx interrupts */
msm_port->imr &= ~UART_IMR_TXLEV;
msm_write(port, msm_port->imr, UART_IMR);
if (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
break;
}
msm_write(port, xmit->buf[xmit->tail],
msm_port->is_uartdm ? UARTDM_TF : UART_TF);
if (msm_port->is_uartdm)
reset_dm_count(port);
num_chars = min(tx_count - tf_pointer, sizeof(buf));
else
num_chars = 1;
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
sent_tx = 1;
for (i = 0; i < num_chars; i++) {
buf[i] = xmit->buf[xmit->tail + i];
port->icount.tx++;
}
msm_write(port, *bf, msm_port->is_uartdm ? UARTDM_TF : UART_TF);
xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1);
tf_pointer += num_chars;
}
/* disable tx interrupts if nothing more to send */
if (uart_circ_empty(xmit))
msm_stop_tx(port);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
@ -759,7 +772,7 @@ static void msm_console_putchar(struct uart_port *port, int c)
struct msm_port *msm_port = UART_TO_MSM(port);
if (msm_port->is_uartdm)
reset_dm_count(port);
reset_dm_count(port, 1);
while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
;