firmware: arm_scmi: Add SCMI PM driver remove routine

[ Upstream commit dea796fcab0a219830831c070b8dc367d7e0f708 ]

Currently, when removing the SCMI PM driver not all the resources
registered with genpd subsystem are properly de-registered.

As a side effect of this after a driver unload/load cycle you get a
splat with a few warnings like this:

 | debugfs: Directory 'BIG_CPU0' with parent 'pm_genpd' already present!
 | debugfs: Directory 'BIG_CPU1' with parent 'pm_genpd' already present!
 | debugfs: Directory 'LITTLE_CPU0' with parent 'pm_genpd' already present!
 | debugfs: Directory 'LITTLE_CPU1' with parent 'pm_genpd' already present!
 | debugfs: Directory 'LITTLE_CPU2' with parent 'pm_genpd' already present!
 | debugfs: Directory 'LITTLE_CPU3' with parent 'pm_genpd' already present!
 | debugfs: Directory 'BIG_SSTOP' with parent 'pm_genpd' already present!
 | debugfs: Directory 'LITTLE_SSTOP' with parent 'pm_genpd' already present!
 | debugfs: Directory 'DBGSYS' with parent 'pm_genpd' already present!
 | debugfs: Directory 'GPUTOP' with parent 'pm_genpd' already present!

Add a proper scmi_pm_domain_remove callback to the driver in order to
take care of all the needed cleanups not handled by devres framework.

Link: https://lore.kernel.org/r/20220817172731.1185305-7-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/firmware/arm_scmi/scmi_pm_domain.c b/drivers/firmware/arm_scmi/scmi_pm_domain.c
index d5dee62..0e05a79 100644 (file)
--- a/drivers/firmware/arm_scmi/scmi_pm_domain.c
+++ b/drivers/firmware/arm_scmi/scmi_pm_domain.c
@@ -112,9 +112,28 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
        scmi_pd_data->domains = domains;
        scmi_pd_data->num_domains = num_domains;
 
+       dev_set_drvdata(dev, scmi_pd_data);
+
        return of_genpd_add_provider_onecell(np, scmi_pd_data);
 }
 
+static void scmi_pm_domain_remove(struct scmi_device *sdev)
+{
+       int i;
+       struct genpd_onecell_data *scmi_pd_data;
+       struct device *dev = &sdev->dev;
+       struct device_node *np = dev->of_node;
+
+       of_genpd_del_provider(np);
+
+       scmi_pd_data = dev_get_drvdata(dev);
+       for (i = 0; i < scmi_pd_data->num_domains; i++) {
+               if (!scmi_pd_data->domains[i])
+                       continue;
+               pm_genpd_remove(scmi_pd_data->domains[i]);
+       }
+}
+
 static const struct scmi_device_id scmi_id_table[] = {
        { SCMI_PROTOCOL_POWER, "genpd" },
        { },
@@ -124,6 +143,7 @@ MODULE_DEVICE_TABLE(scmi, scmi_id_table);
 static struct scmi_driver scmi_power_domain_driver = {
        .name = "scmi-power-domain",
        .probe = scmi_pm_domain_probe,
+       .remove = scmi_pm_domain_remove,
        .id_table = scmi_id_table,
 };
 module_scmi_driver(scmi_power_domain_driver);