remoteproc: Introducing function rproc_attach()

Introducing function rproc_attach() to enact the same actions as
rproc_start(), but without the steps related to the handling of
a firmware image.  That way we can properly deal with scenarios
where the remoteproc core needs to attach with a remote processsor
that has been booted by another entity.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Link: https://lore.kernel.org/r/20200714195035.1426873-4-mathieu.poirier@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index e00dff425c96e6daff301e430608b052532270b9..90842c535dc572ee4888603e46a724c96f7eff0f 100644 (file)
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1372,6 +1372,48 @@ reset_table_ptr:
        return ret;
 }
 
+static int __maybe_unused rproc_attach(struct rproc *rproc)
+{
+       struct device *dev = &rproc->dev;
+       int ret;
+
+       ret = rproc_prepare_subdevices(rproc);
+       if (ret) {
+               dev_err(dev, "failed to prepare subdevices for %s: %d\n",
+                       rproc->name, ret);
+               goto out;
+       }
+
+       /* Attach to the remote processor */
+       ret = rproc_attach_device(rproc);
+       if (ret) {
+               dev_err(dev, "can't attach to rproc %s: %d\n",
+                       rproc->name, ret);
+               goto unprepare_subdevices;
+       }
+
+       /* Start any subdevices for the remote processor */
+       ret = rproc_start_subdevices(rproc);
+       if (ret) {
+               dev_err(dev, "failed to probe subdevices for %s: %d\n",
+                       rproc->name, ret);
+               goto stop_rproc;
+       }
+
+       rproc->state = RPROC_RUNNING;
+
+       dev_info(dev, "remote processor %s is now attached\n", rproc->name);
+
+       return 0;
+
+stop_rproc:
+       rproc->ops->stop(rproc);
+unprepare_subdevices:
+       rproc_unprepare_subdevices(rproc);
+out:
+       return ret;
+}
+
 /*
  * take a firmware and boot a remote processor with it.
  */