serial: 8250_of: manage bus clock in suspend/resume

Save the bus clock pointer in the of_serial_info structure, and use
that to disable the bus clock on suspend and re-enable it on resume.

Signed-off-by: Alex Elder <elder@riscstar.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Reviewed-by: Yixun Lan <dlan@gentoo.org>
Link: https://lore.kernel.org/r/20250411203828.1491595-4-elder@riscstar.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index a90a5462aa72a112d12124ee90d15c77f254d0fc..d178b6c54ea18bae57dfd95bc3ce4c56ddd7380e 100644 (file)
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -24,6 +24,7 @@
 
 struct of_serial_info {
        struct clk *clk;
+       struct clk *bus_clk;
        struct reset_control *rst;
        int type;
        int line;
@@ -138,6 +139,7 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
                        goto err_pmruntime;
                }
 
+               info->bus_clk = bus_clk;
                port->uartclk = clk_get_rate(info->clk);
        }
        /* If current-speed was set, then try not to change it. */
@@ -299,6 +301,7 @@ static int of_serial_suspend(struct device *dev)
        if (!uart_console(port) || console_suspend_enabled) {
                pm_runtime_put_sync(dev);
                clk_disable_unprepare(info->clk);
+               clk_disable_unprepare(info->bus_clk);
        }
        return 0;
 }
@@ -311,6 +314,7 @@ static int of_serial_resume(struct device *dev)
 
        if (!uart_console(port) || console_suspend_enabled) {
                pm_runtime_get_sync(dev);
+               clk_prepare_enable(info->bus_clk);
                clk_prepare_enable(info->clk);
        }