[PATCH v4 11/11] remoteproc: stm32: Update M4 state in stm32_rproc_stop()

[Mathieu Poirier]

Update the co-processor state in function stm32_rproc_stop() so that
it can be used in scenarios where the remoteproc core is attaching
to the M4.

Mainly based on the work published by Arnaud Pouliquen [1].

[1]. https://patchwork.kernel.org/project/linux-remoteproc/list/?series=239877

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
---
 drivers/remoteproc/stm32_rproc.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
index 77a20a638e0c..ad0307aaf3d5 100644
--- a/drivers/remoteproc/stm32_rproc.c
+++ b/drivers/remoteproc/stm32_rproc.c
@@ -503,6 +503,18 @@ static int stm32_rproc_stop(struct rproc *rproc)
 		}
 	}
 
+	/* update coprocessor state to OFF if available */
+	if (ddata->m4_state.map) {
+		err = regmap_update_bits(ddata->m4_state.map,
+					 ddata->m4_state.reg,
+					 ddata->m4_state.mask,
+					 M4_STATE_OFF);
+		if (err) {
+			dev_err(&rproc->dev, "failed to set copro state\n");
+			return err;
+		}
+	}
+
 	return 0;
 }
 
-- 
2.20.1