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serial: at91: make UART support dma and pdc transfers

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Because the UART lack of receive timeout register, so we use a timer to trigger
data receive.
The DBGU is regarded as UART.

Signed-off-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Elen Song 2013-07-22 16:30:30 +08:00 committed by Greg Kroah-Hartman
parent 055560b04a
commit 2e68c22fde
1 changed files with 42 additions and 6 deletions
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48
drivers/tty/serial/atmel_serial.c
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@ -40,6 +40,7 @@
#include <linux/atmel_serial.h>
#include <linux/uaccess.h>
#include <linux/platform_data/atmel.h>
#include <linux/timer.h>
#include <asm/io.h>
#include <asm/ioctls.h>
@ -168,6 +169,7 @@ struct atmel_uart_port {
struct serial_rs485 rs485; /* rs485 settings */
unsigned int tx_done_mask;
bool is_usart; /* usart or uart */
struct timer_list uart_timer; /* uart timer */
int (*prepare_rx)(struct uart_port *port);
int (*prepare_tx)(struct uart_port *port);
void (*schedule_rx)(struct uart_port *port);
@ -822,6 +824,9 @@ static void atmel_release_rx_dma(struct uart_port *port)
atmel_port->desc_rx = NULL;
atmel_port->chan_rx = NULL;
atmel_port->cookie_rx = -EINVAL;
if (!atmel_port->is_usart)
del_timer_sync(&atmel_port->uart_timer);
}
static void atmel_rx_from_dma(struct uart_port *port)
@ -951,6 +956,15 @@ chan_err:
return -EINVAL;
}
static void atmel_uart_timer_callback(unsigned long data)
{
struct uart_port *port = (void *)data;
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
tasklet_schedule(&atmel_port->tasklet);
mod_timer(&atmel_port->uart_timer, jiffies + uart_poll_timeout(port));
}
/*
* receive interrupt handler.
*/
@ -1214,6 +1228,9 @@ static void atmel_release_rx_pdc(struct uart_port *port)
DMA_FROM_DEVICE);
kfree(pdc->buf);
}
if (!atmel_port->is_usart)
del_timer_sync(&atmel_port->uart_timer);
}
static void atmel_rx_from_pdc(struct uart_port *port)
@ -1575,17 +1592,36 @@ static int atmel_startup(struct uart_port *port)
if (atmel_use_pdc_rx(port)) {
/* set UART timeout */
UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
UART_PUT_CR(port, ATMEL_US_STTTO);
if (!atmel_port->is_usart) {
setup_timer(&atmel_port->uart_timer,
atmel_uart_timer_callback,
(unsigned long)port);
mod_timer(&atmel_port->uart_timer,
jiffies + uart_poll_timeout(port));
/* set USART timeout */
} else {
UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
UART_PUT_CR(port, ATMEL_US_STTTO);
UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);
}
/* enable PDC controller */
UART_PUT_PTCR(port, ATMEL_PDC_RXTEN);
} else if (atmel_use_dma_rx(port)) {
UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
UART_PUT_CR(port, ATMEL_US_STTTO);
/* set UART timeout */
if (!atmel_port->is_usart) {
setup_timer(&atmel_port->uart_timer,
atmel_uart_timer_callback,
(unsigned long)port);
mod_timer(&atmel_port->uart_timer,
jiffies + uart_poll_timeout(port));
/* set USART timeout */
} else {
UART_PUT_RTOR(port, PDC_RX_TIMEOUT);
UART_PUT_CR(port, ATMEL_US_STTTO);
UART_PUT_IER(port, ATMEL_US_TIMEOUT);
UART_PUT_IER(port, ATMEL_US_TIMEOUT);
}
} else {
/* enable receive only */
UART_PUT_IER(port, ATMEL_US_RXRDY);