static int msp_serial_handle_irq(struct uart_port *p)
{
struct msp_uart_data *d = p->private_data;
unsigned int iir = readb(p->membase + (UART_IIR << p->regshift));
if (serial8250_handle_irq(p, iir)) {
return 1;
} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
/*
* The DesignWare APB UART has an Busy Detect (0x07) interrupt
* meaning an LCR write attempt occurred while the UART was
* busy. The interrupt must be cleared by reading the UART
* status register (USR) and the LCR re-written.
*
* Note: MSP reserves 0x20 bytes of address space for the UART
* and the USR is mapped in a separate block at an offset of
* 0xc0 from the start of the UART.
*/
(void)readb(p->membase + 0xc0);
writeb(d->last_lcr, p->membase + (UART_LCR << p->regshift));
return 1;
}
return 0;
}
static int msp_serial_handle_irq(struct uart_port *p)
{
struct msp_uart_data *d = p->private_data;
unsigned int iir = readb(p->membase + (UART_IIR << p->regshift));
if (serial8250_handle_irq(p, iir)) {
return 1;
} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
/*
*/
(void)readb(p->membase + 0xc0);
writeb(d->last_lcr, p->membase + (UART_LCR << p->regshift));
return 1;
}
return 0;
}
static int dw8250_handle_irq(struct uart_port *p)
{
struct dw8250_data *d = p->private_data;
unsigned int iir = p->serial_in(p, UART_IIR);
if (serial8250_handle_irq(p, iir)) {
return 1;
} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
/* Clear the USR */
(void)p->serial_in(p, d->usr_reg);
return 1;
}
return 0;
}
static int dw8250_handle_irq(struct uart_port *p)
{
struct dw8250_data *d = p->private_data;
unsigned int iir = p->serial_in(p, UART_IIR);
if (serial8250_handle_irq(p, iir)) {
return 1;
} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
/* Clear the USR and write the LCR again. */
(void)p->serial_in(p, DW_UART_USR);
p->serial_out(p, UART_LCR, d->last_lcr);
return 1;
}
return 0;
}
static int dw8250_handle_irq(struct uart_port *p)
{
struct dw8250_data *d = p->private_data;
unsigned int iir = p->serial_in(p, UART_IIR);
if (serial8250_handle_irq(p, iir)) {
return 1;
} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
(void)p->serial_in(p, UART_USR);
p->serial_out(p, d->last_lcr, UART_LCR);
return 1;
}
return 0;
}
static irqreturn_t omap8250_irq(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct uart_8250_port *up = up_to_u8250p(port);
unsigned int iir;
int ret;
#ifdef CONFIG_SERIAL_8250_DMA
if (up->dma) {
ret = omap_8250_dma_handle_irq(port);
return IRQ_RETVAL(ret);
}
#endif
serial8250_rpm_get(up);
iir = serial_port_in(port, UART_IIR);
ret = serial8250_handle_irq(port, iir);
serial8250_rpm_put(up);
return IRQ_RETVAL(ret);
}
