[PATCH v5 3/5] remoteproc: Add prepare/unprepare callbacks

[Paul Cercueil <paul@crapouillou.net>]

The .prepare() callback is called before the firmware is loaded to
memory. This is useful for instance in the case where some setup is
required for the memory to be accessible.

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

 drivers/remoteproc/remoteproc_core.c | 16 +++++++++++++++-
 include/linux/remoteproc.h           |  4 ++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index fe5c7a2f9767..022b927e176b 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1373,6 +1373,14 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 
 	dev_info(dev, "Booting fw image %s, size %zd\n", name, fw->size);
 
+	if (rproc->ops->prepare) {
+		ret = rproc->ops->prepare(rproc);
+		if (ret) {
+			dev_err(dev, "Failed to prepare rproc: %d\n", ret);
+			return ret;
+		}
+	}
+
 	/*
 	 * if enabling an IOMMU isn't relevant for this rproc, this is
 	 * just a nop
@@ -1380,7 +1388,7 @@ 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 unprepare_rproc;
 	}
 
 	rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
@@ -1424,6 +1432,9 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 	rproc->table_ptr = NULL;
 disable_iommu:
 	rproc_disable_iommu(rproc);
+unprepare_rproc:
+	if (rproc->ops->unprepare)
+		rproc->ops->unprepare(rproc);
 	return ret;
 }
 
@@ -1823,6 +1834,9 @@ void rproc_shutdown(struct rproc *rproc)
 
 	rproc_disable_iommu(rproc);
 
+	if (rproc->ops->unprepare)
+		rproc->ops->unprepare(rproc);
+
 	/* Free the copy of the resource table */
 	kfree(rproc->cached_table);
 	rproc->cached_table = NULL;
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 5f201f0c86c3..a6272d1ba384 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -355,6 +355,8 @@ enum rsc_handling_status {
 
 /**
  * struct rproc_ops - platform-specific device handlers
+ * @prepare:	prepare the device for power up (before the firmware is loaded)
+ * @unprepare:	unprepare the device after it is stopped
  * @start:	power on the device and boot it
  * @stop:	power off the device
  * @kick:	kick a virtqueue (virtqueue id given as a parameter)
@@ -371,6 +373,8 @@ enum rsc_handling_status {
  * @get_boot_addr:	get boot address to entry point specified in firmware
  */
 struct rproc_ops {
+	int (*prepare)(struct rproc *rproc);
+	void (*unprepare)(struct rproc *rproc);
 	int (*start)(struct rproc *rproc);
 	int (*stop)(struct rproc *rproc);
 	void (*kick)(struct rproc *rproc, int vqid);
-- 
2.25.0