[PATCH V2 1/2] memory: tegra: Wire up system sleep PM ops

[Ashish Mhetre]

The tegra-mc platform driver does not register any dev_pm_ops, so the
the SoC-specific ->resume() is never invoked (e.g. tegra186_mc_resume)
on system wake. On Tegra186 and later this means MC client Stream-ID
override registers are not reprogrammed.

Register a dev_pm_ops on the tegra-mc driver and route the system
resume callback into mc->soc->ops->resume() so the existing SID
restore path runs again on wake.

No suspend callback is needed as the resume path reprograms all MC
state from the static SoC tables, so there is nothing to save.

Fixes: fe3b082a6eb8 ("memory: tegra: Add SID override programming for MC clients")
Signed-off-by: Ashish Mhetre <amhetre@xxxxxxxxxx>
---
 drivers/memory/tegra/mc.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index d620660da331..343ac0018eba 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -13,6 +13,7 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm.h>
 #include <linux/slab.h>
 #include <linux/sort.h>
 #include <linux/tegra-icc.h>
@@ -1010,10 +1011,23 @@ static void tegra_mc_sync_state(struct device *dev)
 		icc_sync_state(dev);
 }
 
+static int tegra_mc_resume(struct device *dev)
+{
+	struct tegra_mc *mc = dev_get_drvdata(dev);
+
+	if (mc->soc->ops && mc->soc->ops->resume)
+		return mc->soc->ops->resume(mc);
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(tegra_mc_pm_ops, NULL, tegra_mc_resume);
+
 static struct platform_driver tegra_mc_driver = {
 	.driver = {
 		.name = "tegra-mc",
 		.of_match_table = tegra_mc_of_match,
+		.pm = pm_sleep_ptr(&tegra_mc_pm_ops),
 		.suppress_bind_attrs = true,
 		.sync_state = tegra_mc_sync_state,
 	},
-- 
2.50.1