[PATCH v3] serial: samsung: Re-factors UART IRQ resource for various Samsung SoC

[Tamseel Shams]

In few older Samsung SoCs like s3c2410, s3c2412
and s3c2440, UART IP is having 2 interrupt lines.
However, in other SoCs like s3c6400, s5pv210,
exynos5433, and exynos4210 UART is having only 1
interrupt line. Due to this, "platform_get_irq(platdev, 1)"
call in the driver gives the following warning:
"IRQ index 1 not found" on recent platforms.

This patch re-factors the IRQ resources handling for
each platform and hence fixing the above warnings seen
on some platforms.

Signed-off-by: Tamseel Shams <m.shams at samsung.com>
---
Removed the logic of irq_cnt and directly using
s3c24xx_serial_has_interrupt_mask() to check for
number of interrupt lines.

 drivers/tty/serial/samsung_tty.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 6ef614d8648c..8a955f3d8975 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1908,10 +1908,13 @@ static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 	else {
 		port->irq = ret;
 		ourport->rx_irq = ret;
-		ourport->tx_irq = ret + 1;
+		if (s3c24xx_serial_has_interrupt_mask(port))
+			ourport->tx_irq = ret;
+		else
+			ourport->tx_irq = ret + 1;
 	}
 
-	ret = platform_get_irq(platdev, 1);
+	ret = platform_get_irq_optional(platdev, 1);
 	if (ret > 0)
 		ourport->tx_irq = ret;
 	/*
-- 
2.17.1