diff options
Diffstat (limited to 'drivers/tty/serial/atmel_serial.c')
| -rw-r--r-- | drivers/tty/serial/atmel_serial.c | 92 |
1 files changed, 59 insertions, 33 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 5a341b1c65c3..4a7eb85f7c85 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -175,6 +175,8 @@ struct atmel_uart_port { unsigned int pending_status; spinlock_t lock_suspended; + bool hd_start_rx; /* can start RX during half-duplex operation */ + int (*prepare_rx)(struct uart_port *port); int (*prepare_tx)(struct uart_port *port); void (*schedule_rx)(struct uart_port *port); @@ -241,6 +243,12 @@ static inline void atmel_uart_write_char(struct uart_port *port, u8 value) #endif +static inline int atmel_uart_is_half_duplex(struct uart_port *port) +{ + return (port->rs485.flags & SER_RS485_ENABLED) && + !(port->rs485.flags & SER_RS485_RX_DURING_TX); +} + #ifdef CONFIG_SERIAL_ATMEL_PDC static bool atmel_use_pdc_rx(struct uart_port *port) { @@ -492,9 +500,10 @@ static void atmel_stop_tx(struct uart_port *port) /* Disable interrupts */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); - if ((port->rs485.flags & SER_RS485_ENABLED) && - !(port->rs485.flags & SER_RS485_RX_DURING_TX)) - atmel_start_rx(port); + if (atmel_uart_is_half_duplex(port)) + if (!atomic_read(&atmel_port->tasklet_shutdown)) + atmel_start_rx(port); + } /* @@ -511,8 +520,7 @@ static void atmel_start_tx(struct uart_port *port) return; if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port)) - if ((port->rs485.flags & SER_RS485_ENABLED) && - !(port->rs485.flags & SER_RS485_RX_DURING_TX)) + if (atmel_uart_is_half_duplex(port)) atmel_stop_rx(port); if (atmel_use_pdc_tx(port)) @@ -809,10 +817,14 @@ static void atmel_complete_tx_dma(void *arg) */ if (!uart_circ_empty(xmit)) atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx); - else if ((port->rs485.flags & SER_RS485_ENABLED) && - !(port->rs485.flags & SER_RS485_RX_DURING_TX)) { - /* DMA done, stop TX, start RX for RS485 */ - atmel_start_rx(port); + else if (atmel_uart_is_half_duplex(port)) { + /* + * DMA done, re-enable TXEMPTY and signal that we can stop + * TX and start RX for RS485 + */ + atmel_port->hd_start_rx = true; + atmel_uart_writel(port, ATMEL_US_IER, + atmel_port->tx_done_mask); } spin_unlock_irqrestore(&port->lock, flags); @@ -1166,6 +1178,10 @@ static int atmel_prepare_rx_dma(struct uart_port *port) sg_dma_len(&atmel_port->sg_rx)/2, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); + if (!desc) { + dev_err(port->dev, "Preparing DMA cyclic failed\n"); + goto chan_err; + } desc->callback = atmel_complete_rx_dma; desc->callback_param = port; atmel_port->desc_rx = desc; @@ -1253,9 +1269,19 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending) struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); if (pending & atmel_port->tx_done_mask) { - /* Either PDC or interrupt transmission */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask); + + /* Start RX if flag was set and FIFO is empty */ + if (atmel_port->hd_start_rx) { + if (!(atmel_uart_readl(port, ATMEL_US_CSR) + & ATMEL_US_TXEMPTY)) + dev_warn(port->dev, "Should start RX, but TX fifo is not empty\n"); + + atmel_port->hd_start_rx = false; + atmel_start_rx(port); + } + atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx); } } @@ -1382,8 +1408,7 @@ static void atmel_tx_pdc(struct uart_port *port) atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); } else { - if ((port->rs485.flags & SER_RS485_ENABLED) && - !(port->rs485.flags & SER_RS485_RX_DURING_TX)) { + if (atmel_uart_is_half_duplex(port)) { /* DMA done, stop TX, start RX for RS485 */ atmel_start_rx(port); } @@ -2176,27 +2201,6 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, mode |= ATMEL_US_USMODE_NORMAL; } - /* set the mode, clock divisor, parity, stop bits and data size */ - atmel_uart_writel(port, ATMEL_US_MR, mode); - - /* - * when switching the mode, set the RTS line state according to the - * new mode, otherwise keep the former state - */ - if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) { - unsigned int rts_state; - - if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) { - /* let the hardware control the RTS line */ - rts_state = ATMEL_US_RTSDIS; - } else { - /* force RTS line to low level */ - rts_state = ATMEL_US_RTSEN; - } - - atmel_uart_writel(port, ATMEL_US_CR, rts_state); - } - /* * Set the baud rate: * Fractional baudrate allows to setup output frequency more @@ -2223,6 +2227,28 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, quot = cd | fp << ATMEL_US_FP_OFFSET; atmel_uart_writel(port, ATMEL_US_BRGR, quot); + + /* set the mode, clock divisor, parity, stop bits and data size */ + atmel_uart_writel(port, ATMEL_US_MR, mode); + + /* + * when switching the mode, set the RTS line state according to the + * new mode, otherwise keep the former state + */ + if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) { + unsigned int rts_state; + + if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) { + /* let the hardware control the RTS line */ + rts_state = ATMEL_US_RTSDIS; + } else { + /* force RTS line to low level */ + rts_state = ATMEL_US_RTSEN; + } + + atmel_uart_writel(port, ATMEL_US_CR, rts_state); + } + atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX); atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN); |