Am 14.08.24 um 14:18 schrieb Ulf Hansson:
On Sun, 28 Jul 2024 at 15:07, Stefan Wahren <wahrenst@xxxxxxx> wrote:
This adds suspend/resume support for the 8250_bcm2835aux
driver to provide power management support on attached
devices.
Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>
---
drivers/tty/serial/8250/8250_bcm2835aux.c | 37 +++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_bcm2835aux.c b/drivers/tty/serial/8250/8250_bcm2835aux.c
index 121a5ce86050..36e2bb34d82b 100644
--- a/drivers/tty/serial/8250/8250_bcm2835aux.c
+++ b/drivers/tty/serial/8250/8250_bcm2835aux.c
@@ -13,6 +13,7 @@
*/
#include <linux/clk.h>
+#include <linux/console.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -213,11 +214,47 @@ static const struct acpi_device_id bcm2835aux_serial_acpi_match[] = {
};
MODULE_DEVICE_TABLE(acpi, bcm2835aux_serial_acpi_match);
+static int bcm2835aux_suspend(struct device *dev)
+{
+ struct bcm2835aux_data *data = dev_get_drvdata(dev);
+ struct uart_8250_port *up = serial8250_get_port(data->line);
+
+ serial8250_suspend_port(data->line);
+
+ if (device_may_wakeup(dev))
+ return 0;
+
+ if (uart_console(&up->port) && !console_suspend_enabled)
+ return 0;
+
+ clk_disable_unprepare(data->clk);
+ return 0;
+}
+
+static int bcm2835aux_resume(struct device *dev)
+{
+ struct bcm2835aux_data *data = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(data->clk);
Doesn't this create clk prepare/enable - unprepare/disable imbalance
problem when the uart is configured for system wakeup?
Thanks, i will send a follow-up
Regards
+ if (ret)
+ return ret;
+
+ serial8250_resume_port(data->line);
+
+ return 0;
+}
+
+static const struct dev_pm_ops bcm2835aux_dev_pm_ops = {
+ SYSTEM_SLEEP_PM_OPS(bcm2835aux_suspend, bcm2835aux_resume)
+};
+
static struct platform_driver bcm2835aux_serial_driver = {
.driver = {
.name = "bcm2835-aux-uart",
.of_match_table = bcm2835aux_serial_match,
.acpi_match_table = bcm2835aux_serial_acpi_match,
+ .pm = pm_ptr(&bcm2835aux_dev_pm_ops),
},
.probe = bcm2835aux_serial_probe,
.remove_new = bcm2835aux_serial_remove,
--
2.34.1
Kind regards
Uffe