We need to save/restore the TCR/TTBR registers, since they are lost
on power gate.
Reviewed-by: Sven Peter <sven@xxxxxxxxxxxxx>
Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
---
drivers/iommu/apple-dart.c | 43 ++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index 4f4a323be0d0..2458416122f8 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -121,6 +121,9 @@ struct apple_dart {
struct iommu_group *sid2group[DART_MAX_STREAMS];
struct iommu_device iommu;
+
+ u32 save_tcr[DART_MAX_STREAMS];
+ u32 save_ttbr[DART_MAX_STREAMS][DART_MAX_TTBR];
};
/*
@@ -932,6 +935,45 @@ static const struct apple_dart_hw apple_dart_hw_t6000 = {
.fmt = APPLE_DART2,
};
+static __maybe_unused int apple_dart_suspend(struct device *dev)
+{
+ struct apple_dart *dart = dev_get_drvdata(dev);
+ unsigned int sid, idx;
+
+ for (sid = 0; sid < DART_MAX_STREAMS; sid++) {
+ dart->save_tcr[sid] = readl_relaxed(dart->regs + DART_TCR(sid));
+ for (idx = 0; idx < DART_MAX_TTBR; idx++)
+ dart->save_ttbr[sid][idx] =
+ readl(dart->regs + DART_TTBR(sid, idx));
+ }
+
+ return 0;
+}
+
+static __maybe_unused int apple_dart_resume(struct device *dev)
+{
+ struct apple_dart *dart = dev_get_drvdata(dev);
+ unsigned int sid, idx;
+ int ret;
+
+ ret = apple_dart_hw_reset(dart);
+ if (ret) {
+ dev_err(dev, "Failed to reset DART on resume\n");
+ return ret;
+ }
+
+ for (sid = 0; sid < DART_MAX_STREAMS; sid++) {
+ for (idx = 0; idx < DART_MAX_TTBR; idx++)
+ writel(dart->save_ttbr[sid][idx],
+ dart->regs + DART_TTBR(sid, idx));
+ writel(dart->save_tcr[sid], dart->regs + DART_TCR(sid));
+ }
+
+ return 0;
+}
+
+DEFINE_SIMPLE_DEV_PM_OPS(apple_dart_pm_ops, apple_dart_suspend, apple_dart_resume);
+
static const struct of_device_id apple_dart_of_match[] = {
{ .compatible = "apple,t8103-dart", .data = &apple_dart_hw_t8103 },
{ .compatible = "apple,t6000-dart", .data = &apple_dart_hw_t6000 },
@@ -944,6 +986,7 @@ static struct platform_driver apple_dart_driver = {
.name = "apple-dart",
.of_match_table = apple_dart_of_match,
.suppress_bind_attrs = true,
+ .pm = pm_sleep_ptr(&apple_dart_pm_ops),
},
.probe = apple_dart_probe,
.remove = apple_dart_remove,
--
2.35.1
