[PATCH v4 2/9] remoteproc: Add new attach() remoteproc operation

[Mathieu Poirier]

Add an new attach() operation in order to properly deal with
scenarios where the remoteproc core needs to attach to a
remote processor that has been booted by another entity.

Signed-off-by: Mathieu Poirier <mathieu.poir...@linaro.org>
---
 drivers/remoteproc/remoteproc_internal.h | 8 ++++++++
 include/linux/remoteproc.h               | 2 ++
 2 files changed, 10 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_internal.h 
b/drivers/remoteproc/remoteproc_internal.h
index 4ba7cb59d3e8..fc710866f8ce 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -79,6 +79,14 @@ static inline int rproc_unprepare_device(struct rproc *rproc)
        return 0;
 }
 
+static inline int rproc_attach_device(struct rproc *rproc)
+{
+       if (rproc->ops->attach)
+               return rproc->ops->attach(rproc);
+
+       return 0;
+}
+
 static inline
 int rproc_fw_sanity_check(struct rproc *rproc, const struct firmware *fw)
 {
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 21182ad2d059..bf6a310ba870 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -359,6 +359,7 @@ enum rsc_handling_status {
  * @unprepare: unprepare device after stop
  * @start:     power on the device and boot it
  * @stop:      power off the device
+ * @attach:    attach to a device that his already powered up
  * @kick:      kick a virtqueue (virtqueue id given as a parameter)
  * @da_to_va:  optional platform hook to perform address translations
  * @parse_fw:  parse firmware to extract information (e.g. resource table)
@@ -379,6 +380,7 @@ struct rproc_ops {
        int (*unprepare)(struct rproc *rproc);
        int (*start)(struct rproc *rproc);
        int (*stop)(struct rproc *rproc);
+       int (*attach)(struct rproc *rproc);
        void (*kick)(struct rproc *rproc, int vqid);
        void * (*da_to_va)(struct rproc *rproc, u64 da, size_t len);
        int (*parse_fw)(struct rproc *rproc, const struct firmware *fw);
-- 
2.20.1