[PATCH v4 16/17] remoteproc: Properly deal with detach request

[Mathieu Poirier]

This patch introduces the capability to detach a remote processor
that has been attached to or booted by the remoteproc core.  For
that to happen a rproc::ops::detach() operation need to be
available.

Signed-off-by: Mathieu Poirier <mathieu.poir...@linaro.org>
Reviewed-by: Peng Fan <peng....@nxp.com>
Reviewed-by: Arnaud Pouliquen <arnaud.pouliq...@st.com>
---
 drivers/remoteproc/remoteproc_cdev.c  | 6 ++++++
 drivers/remoteproc/remoteproc_sysfs.c | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_cdev.c 
b/drivers/remoteproc/remoteproc_cdev.c
index 61541bc7d26c..f7645f289563 100644
--- a/drivers/remoteproc/remoteproc_cdev.c
+++ b/drivers/remoteproc/remoteproc_cdev.c
@@ -43,6 +43,12 @@ static ssize_t rproc_cdev_write(struct file *filp, const 
char __user *buf, size_
                        return -EINVAL;
 
                ret = rproc_shutdown(rproc);
+       } else if (!strncmp(cmd, "detach", len)) {
+               if (rproc->state != RPROC_RUNNING &&
+                   rproc->state != RPROC_ATTACHED)
+                       return -EINVAL;
+
+               ret = rproc_detach(rproc);
        } else {
                dev_err(&rproc->dev, "Unrecognized option\n");
                ret = -EINVAL;
diff --git a/drivers/remoteproc/remoteproc_sysfs.c 
b/drivers/remoteproc/remoteproc_sysfs.c
index 298052c9d068..ea7b067fe89a 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -236,6 +236,12 @@ static ssize_t state_store(struct device *dev,
                        return -EINVAL;
 
                ret = rproc_shutdown(rproc);
+       } else if (sysfs_streq(buf, "detach")) {
+               if (rproc->state != RPROC_RUNNING &&
+                   rproc->state != RPROC_ATTACHED)
+                       return -EINVAL;
+
+               ret = rproc_detach(rproc);
        } else {
                dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
                ret = -EINVAL;
-- 
2.25.1