[PATCH v1 13/15] remoteproc: mediatek: Wait SCP core 1 probe done

[Tinghan Shen <tinghan.shen@xxxxxxxxxxxx>]

SCP core 1 driver probing must finish before start loading SCP core 1
image. Add a simple flag checking mechanism when preparing SCP core 1
subdevice.

Signed-off-by: Tinghan Shen <tinghan.shen@xxxxxxxxxxxx>
---
 drivers/remoteproc/mtk_common.h     |  1 +
 drivers/remoteproc/mtk_scp_dual.c   |  2 ++
 drivers/remoteproc/mtk_scp_subdev.c | 35 ++++++++++++++++++++++++++++-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
index a5c26e56277d..464d013ed6b2 100644
--- a/drivers/remoteproc/mtk_common.h
+++ b/drivers/remoteproc/mtk_common.h
@@ -153,6 +153,7 @@ struct mtk_scp {
 
 	struct rproc_subdev *rpmsg_subdev;
 	struct rproc_subdev *dual_subdev;
+	int dual_probe_done;
 };
 
 /**
diff --git a/drivers/remoteproc/mtk_scp_dual.c b/drivers/remoteproc/mtk_scp_dual.c
index 90c49716dd39..ab62ab54175c 100644
--- a/drivers/remoteproc/mtk_scp_dual.c
+++ b/drivers/remoteproc/mtk_scp_dual.c
@@ -266,6 +266,8 @@ static int scp_dual_probe(struct platform_device *pdev)
 	if (ret)
 		goto remove_ipi;
 
+	scp->dual_probe_done = 1;
+
 	return 0;
 
 remove_ipi:
diff --git a/drivers/remoteproc/mtk_scp_subdev.c b/drivers/remoteproc/mtk_scp_subdev.c
index 197fb207c756..71dc6fcad61a 100644
--- a/drivers/remoteproc/mtk_scp_subdev.c
+++ b/drivers/remoteproc/mtk_scp_subdev.c
@@ -20,6 +20,7 @@ static struct mtk_scp *scp_dual_get(struct mtk_scp *scp)
 	struct device *dev = scp->dev;
 	struct device_node *np;
 	struct platform_device *dual_pdev;
+	struct mtk_scp *scp_dual;
 
 	np = of_parse_phandle(dev->of_node, "mediatek,scp-core", SCP_DTS_CORE_REF);
 	dual_pdev = of_find_device_by_node(np);
@@ -30,7 +31,11 @@ static struct mtk_scp *scp_dual_get(struct mtk_scp *scp)
 		return NULL;
 	}
 
-	return platform_get_drvdata(dual_pdev);
+	scp_dual = platform_get_drvdata(dual_pdev);
+	if (!scp_dual)
+		put_device(&dual_pdev->dev);
+
+	return scp_dual;
 }
 
 static void scp_dual_put(struct mtk_scp *scp)
@@ -38,6 +43,33 @@ static void scp_dual_put(struct mtk_scp *scp)
 	put_device(scp->dev);
 }
 
+static int scp_dual_rproc_prepare(struct rproc_subdev *subdev)
+{
+	struct scp_subdev_core *subdev_core = to_subdev_core(subdev);
+	struct mtk_scp *scp = subdev_core->main_scp;
+	unsigned long timeout;
+
+	timeout = jiffies + msecs_to_jiffies(100);
+	while (1) {
+		struct mtk_scp *scp_dual = scp_dual_get(scp);
+
+		if (scp_dual && scp_dual->dual_probe_done) {
+			scp_dual_put(scp_dual);
+			break;
+		}
+
+		if (scp_dual && !scp_dual->dual_probe_done)
+			scp_dual_put(scp_dual);
+
+		if (time_after(jiffies, timeout)) {
+			dev_err(scp->dev, "scp-dual probe timeout\n");
+			return -ETIMEDOUT;
+		}
+	}
+
+	return 0;
+}
+
 static int scp_dual_rproc_start(struct rproc_subdev *subdev)
 {
 	struct scp_subdev_core *subdev_core = to_subdev_core(subdev);
@@ -111,6 +143,7 @@ struct rproc_subdev *scp_dual_create_subdev(struct mtk_scp *scp)
 
 	subdev_core->main_scp = scp;
 	subdev_core->scp_dual_wdt_timeout = scp_dual_wdt_handler;
+	subdev_core->subdev.prepare = scp_dual_rproc_prepare;
 	subdev_core->subdev.start = scp_dual_rproc_start;
 	subdev_core->subdev.stop = scp_dual_rproc_stop;
 
-- 
2.18.0