[PATCH v7 3/5] remoteproc: Add support for runtime PM

[Paul Cercueil <paul@crapouillou.net>]

Call pm_runtime_get_sync() before the firmware is loaded, and
pm_runtime_put() after the remote processor has been stopped.

Even though the remoteproc device has no PM callbacks, this allows the
parent device's PM callbacks to be properly called.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---

Notes:
    v2-v4: No change
    v5: Move calls to prepare/unprepare to rproc_fw_boot/rproc_shutdown
    v6: Instead of prepare/unprepare callbacks, use PM runtime callbacks
    v7: Check return value of pm_runtime_get_sync()

 drivers/remoteproc/remoteproc_core.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index a7f96bc98406..e33d1ef27981 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -29,6 +29,7 @@
 #include <linux/devcoredump.h>
 #include <linux/rculist.h>
 #include <linux/remoteproc.h>
+#include <linux/pm_runtime.h>
 #include <linux/iommu.h>
 #include <linux/idr.h>
 #include <linux/elf.h>
@@ -1382,6 +1383,12 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 	if (ret)
 		return ret;
 
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		dev_err(dev, "pm_runtime_get_sync failed: %d\n", ret);
+		return ret;
+	}
+
 	dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
 
 	/*
@@ -1391,7 +1398,7 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 	ret = rproc_enable_iommu(rproc);
 	if (ret) {
 		dev_err(dev, "can't enable iommu: %d\n", ret);
-		return ret;
+		goto put_pm_runtime;
 	}
 
 	rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
@@ -1435,6 +1442,8 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 	rproc->table_ptr = NULL;
 disable_iommu:
 	rproc_disable_iommu(rproc);
+put_pm_runtime:
+	pm_runtime_put(dev);
 	return ret;
 }
 
@@ -1840,6 +1849,8 @@ void rproc_shutdown(struct rproc *rproc)
 
 	rproc_disable_iommu(rproc);
 
+	pm_runtime_put(dev);
+
 	/* Free the copy of the resource table */
 	kfree(rproc->cached_table);
 	rproc->cached_table = NULL;
@@ -2118,6 +2129,9 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
 
 	rproc->state = RPROC_OFFLINE;
 
+	pm_runtime_no_callbacks(&rproc->dev);
+	pm_runtime_enable(&rproc->dev);
+
 	return rproc;
 }
 EXPORT_SYMBOL(rproc_alloc);
@@ -2133,6 +2147,7 @@ EXPORT_SYMBOL(rproc_alloc);
  */
 void rproc_free(struct rproc *rproc)
 {
+	pm_runtime_disable(&rproc->dev);
 	put_device(&rproc->dev);
 }
 EXPORT_SYMBOL(rproc_free);
-- 
2.26.2