serial: samsung: Enable baud clock for UART reset procedure in resume

[ Upstream commit 1ff3652b ]

Ensure that the baud clock is also enabled for UART register writes in
driver resume. On Exynos5433 SoC this is needed to avoid external abort
issue.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/tty/serial/samsung.c

@@ -1944,7 +1944,11 @@ static int s3c24xx_serial_resume(struct device *dev)
 
 	if (port) {
 		clk_prepare_enable(ourport->clk);
+		if (!IS_ERR(ourport->baudclk))
+			clk_prepare_enable(ourport->baudclk);
 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
+		if (!IS_ERR(ourport->baudclk))
+			clk_disable_unprepare(ourport->baudclk);
 		clk_disable_unprepare(ourport->clk);
 
 		uart_resume_port(&s3c24xx_uart_drv, port);
@@ -1967,7 +1971,11 @@ static int s3c24xx_serial_resume_noirq(struct device *dev)
 			if (rx_enabled(port))
 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
 			clk_prepare_enable(ourport->clk);
+			if (!IS_ERR(ourport->baudclk))
+				clk_prepare_enable(ourport->baudclk);
 			wr_regl(port, S3C64XX_UINTM, uintm);
+			if (!IS_ERR(ourport->baudclk))
+				clk_disable_unprepare(ourport->baudclk);
 			clk_disable_unprepare(ourport->clk);
 		}
 	}