static void serial_omap_start_rxdma(struct uart_omap_port *up)
{
#ifdef CONFIG_OMAP3_PM
/* Disallow OCP bus idle. UART TX irqs are not seen during
* bus idle. Alternative is to set kernel timer at fifo
* drain rate.
*/
unsigned int tmp;
tmp = (serial_in(up, UART_OMAP_SYSC) & 0x7) | (1 << 3);
serial_out(up, UART_OMAP_SYSC, tmp); /* no-idle */
#endif
if (up->uart_dma.rx_dma_channel == 0xFF) {
omap_request_dma(uart_dma_rx[up->pdev->id-1],"UART Rx DMA",
(void *)uart_rx_dma_callback,up,
&(up->uart_dma.rx_dma_channel));
omap_set_dma_src_params(up->uart_dma.rx_dma_channel, 0,
OMAP_DMA_AMODE_CONSTANT,
UART_BASE(up->pdev->id - 1), 0, 0);
omap_set_dma_dest_params(up->uart_dma.rx_dma_channel, 0,
OMAP_DMA_AMODE_POST_INC,
up->uart_dma.rx_buf_dma_phys, 0, 0);
omap_set_dma_transfer_params(up->uart_dma.rx_dma_channel,
OMAP_DMA_DATA_TYPE_S8,
up->uart_dma.rx_buf_size, 1,
OMAP_DMA_SYNC_ELEMENT,
uart_dma_rx[up->pdev->id-1], 0);
}
up->uart_dma.prev_rx_dma_pos = up->uart_dma.rx_buf_dma_phys;
omap_writel(0, OMAP34XX_DMA4_BASE +
OMAP_DMA4_CDAC(up->uart_dma.rx_dma_channel));
omap_start_dma(up->uart_dma.rx_dma_channel);
mod_timer(&up->uart_dma.rx_timer, jiffies +
usecs_to_jiffies(up->uart_dma.rx_timeout));
up->uart_dma.rx_dma_state = 1;
}
static void serial_omap_rx_timeout(unsigned long uart_no)
{
struct uart_omap_port *up = ui[uart_no - 1];
unsigned int curr_dma_pos;
curr_dma_pos = omap_readl(OMAP34XX_DMA4_BASE + OMAP_DMA4_CDAC(up->uart_dma.rx_dma_channel));
if ((curr_dma_pos == up->uart_dma.prev_rx_dma_pos) || (curr_dma_pos == 0)) {
/*
* If there is no transfer rx happening for 10sec then stop the dma
* else just restart the timer. See if 10 sec can be improved.
*/
if (jiffies_to_msecs(jiffies - isr8250_activity) < 10000)
mod_timer(&up->uart_dma.rx_timer, jiffies +
usecs_to_jiffies(up->uart_dma.rx_timeout));
else {
del_timer(&up->uart_dma.rx_timer);
serial_omap_stop_rxdma(up);
up->ier |= UART_IER_RDI;
serial_out(up, UART_IER, up->ier);
}
return;
} else {
unsigned int curr_transmitted_size = curr_dma_pos - up->uart_dma.prev_rx_dma_pos;
up->port.icount.rx += curr_transmitted_size;
tty_insert_flip_string(up->port.state->port.tty, up->uart_dma.rx_buf + (up->uart_dma.prev_rx_dma_pos - up->uart_dma.rx_buf_dma_phys), curr_transmitted_size);
queue_work(omap_serial_workqueue, &up->tty_work);
up->uart_dma.prev_rx_dma_pos = curr_dma_pos;
if (up->uart_dma.rx_buf_size + up->uart_dma.rx_buf_dma_phys == curr_dma_pos) {
serial_omap_start_rxdma(up);
} else
mod_timer(&up->uart_dma.rx_timer,
jiffies + usecs_to_jiffies(up->uart_dma.rx_timeout));
isr8250_activity = jiffies;
}
}
