/* Called with u->lock taken */
static void tegra_start_next_tx(struct tegra_uart_port *t)
{
unsigned long tail;
unsigned long count;
struct circ_buf *xmit;
xmit = &t->uport.state->xmit;
tail = (unsigned long)&xmit->buf[xmit->tail];
count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
dev_vdbg(t->uport.dev, "+%s %lu %d\n", __func__, count,
t->tx_in_progress);
if (count == 0)
goto out;
if (!t->use_tx_dma || count < TEGRA_UART_MIN_DMA)
tegra_start_pio_tx(t, count);
else if (BYTES_TO_ALIGN(tail) > 0)
tegra_start_pio_tx(t, BYTES_TO_ALIGN(tail));
else
tegra_start_dma_tx(t, count);
out:
dev_vdbg(t->uport.dev, "-%s", __func__);
}
static void tegra_uart_start_next_tx(struct tegra_uart_port *tup)
{
unsigned long tail;
unsigned long count;
struct circ_buf *xmit = &tup->uport.state->xmit;
tail = (unsigned long)&xmit->buf[xmit->tail];
count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
if (!count)
return;
if (count < TEGRA_UART_MIN_DMA)
tegra_uart_start_pio_tx(tup, count);
else if (BYTES_TO_ALIGN(tail) > 0)
tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail));
else
tegra_uart_start_tx_dma(tup, count);
}
/* Called with u->lock taken */
static void tegra_start_next_tx(struct tegra_uart_port *t)
{
unsigned long tail;
unsigned long count;
unsigned long lsr;
struct uart_port *u = &t->uport;
struct circ_buf *xmit;
xmit = &t->uport.state->xmit;
tail = (unsigned long)&xmit->buf[xmit->tail];
count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
dev_vdbg(t->uport.dev, "+%s %lu %d\n", __func__, count,
t->tx_in_progress);
if (count == 0) {
if (t->is_irda && !irda_loop) {
do {
lsr = uart_readb(t, UART_LSR);
if (lsr & UART_LSR_TEMT)
break;
} while (1);
tegra_start_rx(u);
}
goto out;
}
if (t->is_irda && !irda_loop) {
if (t->rx_in_progress)
tegra_stop_rx(u);
}
if (!t->use_tx_dma || count < TEGRA_UART_MIN_DMA)
tegra_start_pio_tx(t, count);
else if (BYTES_TO_ALIGN(tail) > 0)
tegra_start_pio_tx(t, BYTES_TO_ALIGN(tail));
else
tegra_start_dma_tx(t, count);
out:
dev_vdbg(t->uport.dev, "-%s", __func__);
}
static void sirfsoc_uart_tx_with_dma(struct sirfsoc_uart_port *sirfport)
{
struct uart_port *port = &sirfport->port;
struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
struct sirfsoc_int_en *uint_en = &sirfport->uart_reg->uart_int_en;
struct circ_buf *xmit = &port->state->xmit;
unsigned long tran_size;
unsigned long tran_start;
unsigned long pio_tx_size;
tran_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
tran_start = (unsigned long)(xmit->buf + xmit->tail);
if (uart_circ_empty(xmit) || uart_tx_stopped(port) ||
!tran_size)
return;
if (sirfport->tx_dma_state == TX_DMA_PAUSE) {
dmaengine_resume(sirfport->tx_dma_chan);
return;
}
if (sirfport->tx_dma_state == TX_DMA_RUNNING)
return;
if (!sirfport->is_atlas7)
wr_regl(port, ureg->sirfsoc_int_en_reg,
rd_regl(port, ureg->sirfsoc_int_en_reg)&
~(uint_en->sirfsoc_txfifo_empty_en));
else
wr_regl(port, SIRFUART_INT_EN_CLR,
uint_en->sirfsoc_txfifo_empty_en);
/*
* DMA requires buffer address and buffer length are both aligned with
* 4 bytes, so we use PIO for
* 1. if address is not aligned with 4bytes, use PIO for the first 1~3
* bytes, and move to DMA for the left part aligned with 4bytes
* 2. if buffer length is not aligned with 4bytes, use DMA for aligned
* part first, move to PIO for the left 1~3 bytes
*/
if (tran_size < 4 || BYTES_TO_ALIGN(tran_start)) {
wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_STOP);
wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl,
rd_regl(port, ureg->sirfsoc_tx_dma_io_ctrl)|
SIRFUART_IO_MODE);
if (BYTES_TO_ALIGN(tran_start)) {
pio_tx_size = sirfsoc_uart_pio_tx_chars(sirfport,
BYTES_TO_ALIGN(tran_start));
tran_size -= pio_tx_size;
}
if (tran_size < 4)
sirfsoc_uart_pio_tx_chars(sirfport, tran_size);
if (!sirfport->is_atlas7)
wr_regl(port, ureg->sirfsoc_int_en_reg,
rd_regl(port, ureg->sirfsoc_int_en_reg)|
uint_en->sirfsoc_txfifo_empty_en);
else
wr_regl(port, ureg->sirfsoc_int_en_reg,
uint_en->sirfsoc_txfifo_empty_en);
wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
} else {
/* tx transfer mode switch into dma mode */
wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_STOP);
wr_regl(port, ureg->sirfsoc_tx_dma_io_ctrl,
rd_regl(port, ureg->sirfsoc_tx_dma_io_ctrl)&
~SIRFUART_IO_MODE);
wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
tran_size &= ~(0x3);
sirfport->tx_dma_addr = dma_map_single(port->dev,
xmit->buf + xmit->tail,
tran_size, DMA_TO_DEVICE);
sirfport->tx_dma_desc = dmaengine_prep_slave_single(
sirfport->tx_dma_chan, sirfport->tx_dma_addr,
tran_size, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
if (!sirfport->tx_dma_desc) {
dev_err(port->dev, "DMA prep slave single fail\n");
return;
}
sirfport->tx_dma_desc->callback =
sirfsoc_uart_tx_dma_complete_callback;
sirfport->tx_dma_desc->callback_param = (void *)sirfport;
sirfport->transfer_size = tran_size;
dmaengine_submit(sirfport->tx_dma_desc);
dma_async_issue_pending(sirfport->tx_dma_chan);
sirfport->tx_dma_state = TX_DMA_RUNNING;
}
}
