/*
* This is mostly serial8250_handle_irq(). We have a slightly different DMA
* hoook for RX/TX and need different logic for them in the ISR. Therefore we
* use the default routine in the non-DMA case and this one for with DMA.
*/
static int omap_8250_dma_handle_irq(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
unsigned char status;
unsigned long flags;
u8 iir;
int dma_err = 0;
serial8250_rpm_get(up);
iir = serial_port_in(port, UART_IIR);
if (iir & UART_IIR_NO_INT) {
serial8250_rpm_put(up);
return 0;
}
spin_lock_irqsave(&port->lock, flags);
status = serial_port_in(port, UART_LSR);
if (status & (UART_LSR_DR | UART_LSR_BI)) {
dma_err = omap_8250_rx_dma(up, iir);
if (dma_err) {
status = serial8250_rx_chars(up, status);
omap_8250_rx_dma(up, 0);
}
}
serial8250_modem_status(up);
if (status & UART_LSR_THRE && up->dma->tx_err) {
if (uart_tx_stopped(&up->port) ||
uart_circ_empty(&up->port.state->xmit)) {
up->dma->tx_err = 0;
serial8250_tx_chars(up);
} else {
/*
* try again due to an earlier failer which
* might have been resolved by now.
*/
dma_err = omap_8250_tx_dma(up);
if (dma_err)
serial8250_tx_chars(up);
}
}
spin_unlock_irqrestore(&port->lock, flags);
serial8250_rpm_put(up);
return 1;
}
static int omap8250_runtime_suspend(struct device *dev)
{
struct omap8250_priv *priv = dev_get_drvdata(dev);
struct uart_8250_port *up;
up = serial8250_get_port(priv->line);
/*
* When using 'no_console_suspend', the console UART must not be
* suspended. Since driver suspend is managed by runtime suspend,
* preventing runtime suspend (by returning error) will keep device
* active during suspend.
*/
if (priv->is_suspending && !console_suspend_enabled) {
if (uart_console(&up->port))
return -EBUSY;
}
omap8250_enable_wakeup(priv, true);
if (up->dma)
omap_8250_rx_dma(up, UART_IIR_RX_TIMEOUT);
priv->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
schedule_work(&priv->qos_work);
return 0;
}
static void __dma_rx_complete(void *param)
{
struct uart_8250_port *p = param;
struct omap8250_priv *priv = p->port.private_data;
struct uart_8250_dma *dma = p->dma;
struct dma_tx_state state;
unsigned long flags;
spin_lock_irqsave(&p->port.lock, flags);
/*
* If the tx status is not DMA_COMPLETE, then this is a delayed
* completion callback. A previous RX timeout flush would have
* already pushed the data, so exit.
*/
if (dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state) !=
DMA_COMPLETE) {
spin_unlock_irqrestore(&p->port.lock, flags);
return;
}
__dma_rx_do_complete(p);
if (!priv->throttled)
omap_8250_rx_dma(p);
spin_unlock_irqrestore(&p->port.lock, flags);
}
static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
{
switch (iir & 0x3f) {
case UART_IIR_RLSI:
case UART_IIR_RX_TIMEOUT:
case UART_IIR_RDI:
omap_8250_rx_dma_flush(up);
return true;
}
return omap_8250_rx_dma(up);
}
static int omap8250_runtime_resume(struct device *dev)
{
struct omap8250_priv *priv = dev_get_drvdata(dev);
struct uart_8250_port *up;
/* In case runtime-pm tries this before we are setup */
if (!priv)
return 0;
up = serial8250_get_port(priv->line);
if (omap8250_lost_context(up))
omap8250_restore_regs(up);
if (up->dma && up->dma->rxchan)
omap_8250_rx_dma(up);
priv->latency = priv->calc_latency;
schedule_work(&priv->qos_work);
return 0;
}
static void __dma_rx_do_complete(struct uart_8250_port *p, bool error)
{
struct uart_8250_dma *dma = p->dma;
struct tty_port *tty_port = &p->port.state->port;
struct dma_tx_state state;
int count;
dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
dma->rx_size, DMA_FROM_DEVICE);
dma->rx_running = 0;
dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
dmaengine_terminate_all(dma->rxchan);
count = dma->rx_size - state.residue;
tty_insert_flip_string(tty_port, dma->rx_buf, count);
p->port.icount.rx += count;
if (!error)
omap_8250_rx_dma(p, 0);
tty_flip_buffer_push(tty_port);
}
static int omap8250_runtime_resume(struct device *dev)
{
struct omap8250_priv *priv = dev_get_drvdata(dev);
struct uart_8250_port *up;
int loss_cntx;
/* In case runtime-pm tries this before we are setup */
if (!priv)
return 0;
up = serial8250_get_port(priv->line);
omap8250_enable_wakeup(priv, false);
loss_cntx = omap8250_lost_context(up);
if (loss_cntx)
omap8250_restore_regs(up);
if (up->dma)
omap_8250_rx_dma(up, 0);
priv->latency = priv->calc_latency;
schedule_work(&priv->qos_work);
return 0;
}
static void __dma_rx_complete(void *param)
{
__dma_rx_do_complete(param);
omap_8250_rx_dma(param);
}
