[U-Boot] [PATCH 4/4] dm: core: device: switch off power domain after device removal

Lokesh Vutla lokeshvutla at ti.com
Fri Sep 27 08:18:15 UTC 2019

From: Anatolij Gustschin <agust at denx.de>

The power domain associated with a device is enabled when probing,
but currently the domain remains enabled when the device is removed.
Some boards started to disable power domains for selected devices
via custom board_quiesce_devices(), but it doesn't work in many
cases, i. e. because devices still can be accessed later in
.remove() callback on behalf of dm_remove_devices_flags().

Utilize the DM core to power off the device power domain, but add a
device flag to be able to selectively let the power domain enabled
after device removal. This might be required for devices that must
remain enabled when booting OS, i. e. serial console for debug
output, etc.

Signed-off-by: Anatolij Gustschin <agust at denx.de>
Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
 drivers/core/device-remove.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c
index 586fadee0a..5c8dc4ad70 100644
--- a/drivers/core/device-remove.c
+++ b/drivers/core/device-remove.c
@@ -16,6 +16,7 @@
 #include <dm/uclass.h>
 #include <dm/uclass-internal.h>
 #include <dm/util.h>
+#include <power-domain.h>
 int device_chld_unbind(struct udevice *dev, struct driver *drv)
@@ -192,6 +193,10 @@ int device_remove(struct udevice *dev, uint flags)
+	if (!(drv->flags & DM_FLAG_DEFAULT_PD_CTRL_OFF) &&
+	    (dev != gd->cur_serial_dev))
+		dev_power_domain_off(dev);
 	if (flags_remove(flags, drv->flags)) {

More information about the U-Boot mailing list