[PATCH v3 08/15] remoteproc: Introduce function __rproc_detach()

From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: ohad@wizery.com, bjorn.andersson@linaro.org, robh+dt@kernel.org
Cc: linux-remoteproc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, arnaud.pouliquen@st.com
Subject: [PATCH v3 08/15] remoteproc: Introduce function __rproc_detach()
Date: Thu, 26 Nov 2020 14:06:35 -0700	[thread overview]
Message-ID: <20201126210642.897302-9-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <20201126210642.897302-1-mathieu.poirier@linaro.org>

Introduce function __rproc_detach() to perform the same kind of
operation as rproc_stop(), but instead of switching off the
remote processor using rproc->ops->stop(), it uses
rproc->ops->detach().  That way it is possible for the core
to release the resources associated with a remote processor while
the latter is kept operating.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/remoteproc/remoteproc_core.c | 31 ++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 539667948bc8..928b3f975798 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1664,6 +1664,37 @@ static int rproc_stop(struct rproc *rproc, bool crashed)
 	return 0;
 }
 
+/*
+ * __rproc_detach(): Does the opposite of rproc_attach()
+ */
+static int __maybe_unused __rproc_detach(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	/* No need to continue if a detach() operation has not been provided */
+	if (!rproc->ops->detach)
+		return -EINVAL;
+
+	/* Stop any subdevices for the remote processor */
+	rproc_stop_subdevices(rproc, false);
+
+	/* Tell the remote processor the core isn't available anymore */
+	ret = rproc->ops->detach(rproc);
+	if (ret) {
+		dev_err(dev, "can't detach from rproc: %d\n", ret);
+		rproc_start_subdevices(rproc);
+		return ret;
+	}
+
+	rproc_unprepare_subdevices(rproc);
+
+	rproc->state = RPROC_DETACHED;
+
+	dev_info(dev, "detached remote processor %s\n", rproc->name);
+
+	return 0;
+}
 
 /**
  * rproc_trigger_recovery() - recover a remoteproc
-- 
2.25.1

