diff options
| -rw-r--r-- | drivers/tty/serial/samsung.c | 238 | ||||
| -rw-r--r-- | drivers/tty/serial/samsung.h | 3 |
2 files changed, 225 insertions, 16 deletions
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index 825c8192b944..c04618052e53 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -81,6 +81,8 @@ static void dbg(const char *fmt, ...) #define S3C24XX_SERIAL_MAJOR 204 #define S3C24XX_SERIAL_MINOR 64 +#define S3C24XX_TX_PIO 1 +#define S3C24XX_TX_DMA 2 /* macros to change one thing to another */ #define tx_enabled(port) ((port)->unused[0]) @@ -157,33 +159,217 @@ static void s3c24xx_serial_rx_disable(struct uart_port *port) static void s3c24xx_serial_stop_tx(struct uart_port *port) { struct s3c24xx_uart_port *ourport = to_ourport(port); + struct s3c24xx_uart_dma *dma = ourport->dma; + struct circ_buf *xmit = &port->state->xmit; + struct dma_tx_state state; + int count; - if (tx_enabled(port)) { - if (s3c24xx_serial_has_interrupt_mask(port)) - __set_bit(S3C64XX_UINTM_TXD, - portaddrl(port, S3C64XX_UINTM)); - else - disable_irq_nosync(ourport->tx_irq); - tx_enabled(port) = 0; - if (port->flags & UPF_CONS_FLOW) - s3c24xx_serial_rx_enable(port); + if (!tx_enabled(port)) + return; + + if (s3c24xx_serial_has_interrupt_mask(port)) + __set_bit(S3C64XX_UINTM_TXD, + portaddrl(port, S3C64XX_UINTM)); + else + disable_irq_nosync(ourport->tx_irq); + + if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) { + dmaengine_pause(dma->tx_chan); + dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state); + dmaengine_terminate_all(dma->tx_chan); + dma_sync_single_for_cpu(ourport->port.dev, + dma->tx_transfer_addr, dma->tx_size, DMA_TO_DEVICE); + async_tx_ack(dma->tx_desc); + count = dma->tx_bytes_requested - state.residue; + xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); + port->icount.tx += count; } + + tx_enabled(port) = 0; + ourport->tx_in_progress = 0; + + if (port->flags & UPF_CONS_FLOW) + s3c24xx_serial_rx_enable(port); + + ourport->tx_mode = 0; +} + +static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport); + +static void s3c24xx_serial_tx_dma_complete(void *args) +{ + struct s3c24xx_uart_port *ourport = args; + struct uart_port *port = &ourport->port; + struct circ_buf *xmit = &port->state->xmit; + struct s3c24xx_uart_dma *dma = ourport->dma; + struct dma_tx_state state; + unsigned long flags; + int count; + + + dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state); + count = dma->tx_bytes_requested - state.residue; + async_tx_ack(dma->tx_desc); + + dma_sync_single_for_cpu(ourport->port.dev, dma->tx_transfer_addr, + dma->tx_size, DMA_TO_DEVICE); + + spin_lock_irqsave(&port->lock, flags); + + xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); + port->icount.tx += count; + ourport->tx_in_progress = 0; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + s3c24xx_serial_start_next_tx(ourport); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void enable_tx_dma(struct s3c24xx_uart_port *ourport) +{ + struct uart_port *port = &ourport->port; + u32 ucon; + + /* Mask Tx interrupt */ + if (s3c24xx_serial_has_interrupt_mask(port)) + __set_bit(S3C64XX_UINTM_TXD, + portaddrl(port, S3C64XX_UINTM)); + else + disable_irq_nosync(ourport->tx_irq); + + /* Enable tx dma mode */ + ucon = rd_regl(port, S3C2410_UCON); + ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK); + ucon |= (dma_get_cache_alignment() >= 16) ? + S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1; + ucon |= S3C64XX_UCON_TXMODE_DMA; + wr_regl(port, S3C2410_UCON, ucon); + + ourport->tx_mode = S3C24XX_TX_DMA; +} + +static void enable_tx_pio(struct s3c24xx_uart_port *ourport) +{ + struct uart_port *port = &ourport->port; + u32 ucon, ufcon; + + /* Set ufcon txtrig */ + ourport->tx_in_progress = S3C24XX_TX_PIO; + ufcon = rd_regl(port, S3C2410_UFCON); + wr_regl(port, S3C2410_UFCON, ufcon); + + /* Enable tx pio mode */ + ucon = rd_regl(port, S3C2410_UCON); + ucon &= ~(S3C64XX_UCON_TXMODE_MASK); + ucon |= S3C64XX_UCON_TXMODE_CPU; + wr_regl(port, S3C2410_UCON, ucon); + + /* Unmask Tx interrupt */ + if (s3c24xx_serial_has_interrupt_mask(port)) + __clear_bit(S3C64XX_UINTM_TXD, + portaddrl(port, S3C64XX_UINTM)); + else + enable_irq(ourport->tx_irq); + + ourport->tx_mode = S3C24XX_TX_PIO; } -static void s3c24xx_serial_start_tx(struct uart_port *port) +static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport) +{ + if (ourport->tx_mode != S3C24XX_TX_PIO) + enable_tx_pio(ourport); +} + +static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport, + unsigned int count) +{ + struct uart_port *port = &ourport->port; + struct circ_buf *xmit = &port->state->xmit; + struct s3c24xx_uart_dma *dma = ourport->dma; + + + if (ourport->tx_mode != S3C24XX_TX_DMA) + enable_tx_dma(ourport); + + while (xmit->tail & (dma_get_cache_alignment() - 1)) { + if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull) + return 0; + wr_regb(port, S3C2410_UTXH, xmit->buf[xmit->tail]); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + count--; + } + + dma->tx_size = count & ~(dma_get_cache_alignment() - 1); + dma->tx_transfer_addr = dma->tx_addr + xmit->tail; + + dma_sync_single_for_device(ourport->port.dev, dma->tx_transfer_addr, + dma->tx_size, DMA_TO_DEVICE); + + dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan, + dma->tx_transfer_addr, dma->tx_size, + DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT); + if (!dma->tx_desc) { + dev_err(ourport->port.dev, "Unable to get desc for Tx\n"); + return -EIO; + } + + dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete; + dma->tx_desc->callback_param = ourport; + dma->tx_bytes_requested = dma->tx_size; + + ourport->tx_in_progress = S3C24XX_TX_DMA; + dma->tx_cookie = dmaengine_submit(dma->tx_desc); + dma_async_issue_pending(dma->tx_chan); + return 0; +} + +static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport) +{ + struct uart_port *port = &ourport->port; + struct circ_buf *xmit = &port->state->xmit; + unsigned long count; + + /* Get data size up to the end of buffer */ + count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + + if (!count) { + s3c24xx_serial_stop_tx(port); + return; + } + + if (!ourport->dma || !ourport->dma->tx_chan || count < port->fifosize) + s3c24xx_serial_start_tx_pio(ourport); + else + s3c24xx_serial_start_tx_dma(ourport, count); +} + +void s3c24xx_serial_start_tx(struct uart_port *port) { struct s3c24xx_uart_port *ourport = to_ourport(port); + struct circ_buf *xmit = &port->state->xmit; if (!tx_enabled(port)) { if (port->flags & UPF_CONS_FLOW) s3c24xx_serial_rx_disable(port); - if (s3c24xx_serial_has_interrupt_mask(port)) - __clear_bit(S3C64XX_UINTM_TXD, - portaddrl(port, S3C64XX_UINTM)); - else - enable_irq(ourport->tx_irq); tx_enabled(port) = 1; + if (!ourport->dma || !ourport->dma->tx_chan) { + if (s3c24xx_serial_has_interrupt_mask(port)) + __clear_bit(S3C64XX_UINTM_TXD, + portaddrl(port, S3C64XX_UINTM)); + else + enable_irq(ourport->tx_irq); + + s3c24xx_serial_start_tx_pio(ourport); + } + } + + if (ourport->dma && ourport->dma->tx_chan) { + if (!uart_circ_empty(xmit) && !ourport->tx_in_progress) + s3c24xx_serial_start_next_tx(ourport); } } @@ -333,10 +519,17 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) struct uart_port *port = &ourport->port; struct circ_buf *xmit = &port->state->xmit; unsigned long flags; - int count = port->fifosize; + int count; spin_lock_irqsave(&port->lock, flags); + count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + + if (ourport->dma && ourport->dma->tx_chan && count >= port->fifosize) { + s3c24xx_serial_start_tx_dma(ourport, count); + goto out; + } + if (port->x_char) { wr_regb(port, S3C2410_UTXH, port->x_char); port->icount.tx++; @@ -355,6 +548,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id) /* try and drain the buffer... */ + count = port->fifosize; while (!uart_circ_empty(xmit) && count-- > 0) { if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull) break; @@ -572,6 +766,7 @@ static void s3c24xx_serial_shutdown(struct uart_port *port) if (ourport->dma) s3c24xx_serial_release_dma(ourport); + ourport->tx_in_progress = 0; } static int s3c24xx_serial_startup(struct uart_port *port) @@ -650,8 +845,19 @@ static int s3c64xx_serial_startup(struct uart_port *port) tx_enabled(port) = 0; ourport->tx_claimed = 1; + spin_lock_irqsave(&port->lock, flags); + + ufcon = rd_regl(port, S3C2410_UFCON); + ufcon |= S3C2410_UFCON_RESETRX | S3C2410_UFCON_RESETTX; + wr_regl(port, S3C2410_UFCON, ufcon); + + enable_rx_pio(ourport); + + spin_unlock_irqrestore(&port->lock, flags); + /* Enable Rx Interrupt */ __clear_bit(S3C64XX_UINTM_RXD, portaddrl(port, S3C64XX_UINTM)); + dbg("s3c64xx_serial_startup ok\n"); return ret; } diff --git a/drivers/tty/serial/samsung.h b/drivers/tty/serial/samsung.h index 8dc250c6b472..e60011c591e8 100644 --- a/drivers/tty/serial/samsung.h +++ b/drivers/tty/serial/samsung.h @@ -86,6 +86,9 @@ struct s3c24xx_uart_port { unsigned int rx_irq; unsigned int tx_irq; + unsigned int tx_in_progress; + unsigned int tx_mode; + struct s3c24xx_uart_info *info; struct clk *clk; struct clk *baudclk; |