/**
* cdns_uart_isr - Interrupt handler
* @irq: Irq number
* @dev_id: Id of the port
*
* Return: IRQHANDLED
*/
static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
{
struct uart_port *port = (struct uart_port *)dev_id;
unsigned long flags;
unsigned int isrstatus;
spin_lock_irqsave(&port->lock, flags);
/* Read the interrupt status register to determine which
* interrupt(s) is/are active.
*/
isrstatus = readl(port->membase + CDNS_UART_ISR);
if (isrstatus & CDNS_UART_RX_IRQS)
cdns_uart_handle_rx(port, isrstatus);
if ((isrstatus & CDNS_UART_IXR_TXEMPTY) == CDNS_UART_IXR_TXEMPTY)
cdns_uart_handle_tx(port);
writel(isrstatus, port->membase + CDNS_UART_ISR);
/* be sure to release the lock and tty before leaving */
spin_unlock_irqrestore(&port->lock, flags);
return IRQ_HANDLED;
}
/**
* cdns_uart_start_tx - Start transmitting bytes
* @port: Handle to the uart port structure
*/
static void cdns_uart_start_tx(struct uart_port *port)
{
unsigned int status;
if (uart_tx_stopped(port))
return;
/*
* Set the TX enable bit and clear the TX disable bit to enable the
* transmitter.
*/
status = readl(port->membase + CDNS_UART_CR);
status &= ~CDNS_UART_CR_TX_DIS;
status |= CDNS_UART_CR_TX_EN;
writel(status, port->membase + CDNS_UART_CR);
if (uart_circ_empty(&port->state->xmit))
return;
cdns_uart_handle_tx(port);
writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);
/* Enable the TX Empty interrupt */
writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IER);
}
/**
* cdns_uart_isr - Interrupt handler
* @irq: Irq number
* @dev_id: Id of the port
*
* Return: IRQHANDLED
*/
static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
{
struct uart_port *port = (struct uart_port *)dev_id;
unsigned int isrstatus;
spin_lock(&port->lock);
/* Read the interrupt status register to determine which
* interrupt(s) is/are active and clear them.
*/
isrstatus = cdns_uart_readl(CDNS_UART_ISR_OFFSET);
cdns_uart_writel(isrstatus, CDNS_UART_ISR_OFFSET);
if (isrstatus & CDNS_UART_IXR_TXEMPTY) {
cdns_uart_handle_tx(dev_id);
isrstatus &= ~CDNS_UART_IXR_TXEMPTY;
}
if (isrstatus & CDNS_UART_IXR_MASK)
cdns_uart_handle_rx(dev_id, isrstatus);
spin_unlock(&port->lock);
return IRQ_HANDLED;
}
