[PATCH v5] arm pl011 serial: support multi-irq request

Bing Fan
2021-07-01T01:38:43Z

From: Bing Fan <tombinfan@tencent.com>

In order to make pl011 work better, multiple interrupts are
required, such as TXIM, RXIM, RTIM, error interrupt(FE/PE/BE/OE);
at the same time, pl011 to GIC does not merge the interrupt
lines(each serial-interrupt corresponding to different GIC hardware
interrupt), so need to enable and request multiple gic interrupt
numbers in the driver.

Signed-off-by: Bing Fan <tombinfan@tencent.com>
---
drivers/tty/serial/amba-pl011.c | 34 ++++++++++++++++++++++++++++++---
1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 78682c12156a..7bfe8efcc787 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1701,11 +1701,39 @@ static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
}
}

+static void pl011_release_irq(struct uart_amba_port *uap, unsigned int max_cnt)
+{
+ struct amba_device *amba_dev = container_of(uap->port.dev, struct amba_device, dev);
+ int i;
+
+ for (i = 0; i < max_cnt; i++)
+ if (amba_dev->irq[i])
+ free_irq(amba_dev->irq[i], uap);
+}
+
static int pl011_allocate_irq(struct uart_amba_port *uap)
{
+ int ret = 0;
+ int i;
+ unsigned int virq;
+ struct amba_device *amba_dev = container_of(uap->port.dev, struct amba_device, dev);
+
pl011_write(uap->im, uap, REG_IMSC);

- return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
+ for (i = 0; i < AMBA_NR_IRQS; i++) {
+ virq = amba_dev->irq[i];
+ if (virq == 0)
+ break;
+
+ ret = request_irq(virq, pl011_int, IRQF_SHARED, dev_name(&amba_dev->dev), uap);
+ if (ret) {
+ dev_err(uap->port.dev, "request %u interrupt failed\n", virq);
+ pl011_release_irq(uap, i - 1);
+ break;
+ }
+ }
+
+ return ret;
}

/*
@@ -1864,7 +1892,7 @@ static void pl011_shutdown(struct uart_port *port)

pl011_dma_shutdown(uap);

- free_irq(uap->port.irq, uap);
+ pl011_release_irq(uap, AMBA_NR_IRQS);

pl011_disable_uart(uap);

@@ -1894,7 +1922,7 @@ static void sbsa_uart_shutdown(struct uart_port *port)

pl011_disable_interrupts(uap);

- free_irq(uap->port.irq, uap);
+ pl011_release_irq(uap, AMBA_NR_IRQS);

if (uap->port.ops->flush_buffer)
uap->port.ops->flush_buffer(port);
--
2.17.1