remoteproc: qcom: wcnss: Fix race with iris probe

The remoteproc driver is split between the responsibilities of getting
the SoC-internal ARM core up and running and the external RF (aka
"Iris") part configured.

In order to satisfy the regulator framework's need of a struct device *
to look up supplies this was implemented as two different drivers, using
of_platform_populate() in the remoteproc part to probe the iris part.

Unfortunately it's possible that the iris part probe defers on yet not
available regulators and an attempt to start the remoteproc will have to
be rejected, until this has been resolved. But there's no useful
mechanism of knowing when this would be.

Instead replace the of_platform_populate() and the iris probe with a
function that rolls its own struct device, with the relevant of_node
associated that is enough to acquire regulators and clocks specified in
the DT node and that may propagate the EPROBE_DEFER back to the wcnss
device's probe.

Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reported-by: Anibal Limon <anibal.limon@linaro.org>
Reported-by: Loic Poulain <loic.poulain@linaro.org>
Tested-by: Anibal Limon <anibal.limon@linaro.org>
Link: https://lore.kernel.org/r/20210312002251.3273013-1-bjorn.andersson@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

1 files changed, 12 insertions, 37 deletions

diff --git a/drivers/remoteproc/qcom_wcnss.c b/drivers/remoteproc/qcom_wcnss.c
index f1cbc6b2edbb..ebadc6c08e11 100644
--- a/drivers/remoteproc/qcom_wcnss.c
+++ b/drivers/remoteproc/qcom_wcnss.c
@@ -142,18 +142,6 @@ static const struct wcnss_data pronto_v2_data = {
 	.num_vregs = 1,
 };
 
-void qcom_wcnss_assign_iris(struct qcom_wcnss *wcnss,
-			    struct qcom_iris *iris,
-			    bool use_48mhz_xo)
-{
-	mutex_lock(&wcnss->iris_lock);
-
-	wcnss->iris = iris;
-	wcnss->use_48mhz_xo = use_48mhz_xo;
-
-	mutex_unlock(&wcnss->iris_lock);
-}
-
 static int wcnss_load(struct rproc *rproc, const struct firmware *fw)
 {
 	struct qcom_wcnss *wcnss = (struct qcom_wcnss *)rproc->priv;
@@ -639,12 +627,20 @@ static int wcnss_probe(struct platform_device *pdev)
 		goto detach_pds;
 	}
 
+	wcnss->iris = qcom_iris_probe(&pdev->dev, &wcnss->use_48mhz_xo);
+	if (IS_ERR(wcnss->iris)) {
+		ret = PTR_ERR(wcnss->iris);
+		goto detach_pds;
+	}
+
 	ret = rproc_add(rproc);
 	if (ret)
-		goto detach_pds;
+		goto remove_iris;
 
-	return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+	return 0;
 
+remove_iris:
+	qcom_iris_remove(wcnss->iris);
 detach_pds:
 	wcnss_release_pds(wcnss);
 free_rproc:
@@ -657,7 +653,7 @@ static int wcnss_remove(struct platform_device *pdev)
 {
 	struct qcom_wcnss *wcnss = platform_get_drvdata(pdev);
 
-	of_platform_depopulate(&pdev->dev);
+	qcom_iris_remove(wcnss->iris);
 
 	rproc_del(wcnss->rproc);
 
@@ -686,28 +682,7 @@ static struct platform_driver wcnss_driver = {
 	},
 };
 
-static int __init wcnss_init(void)
-{
-	int ret;
-
-	ret = platform_driver_register(&wcnss_driver);
-	if (ret)
-		return ret;
-
-	ret = platform_driver_register(&qcom_iris_driver);
-	if (ret)
-		platform_driver_unregister(&wcnss_driver);
-
-	return ret;
-}
-module_init(wcnss_init);
-
-static void __exit wcnss_exit(void)
-{
-	platform_driver_unregister(&qcom_iris_driver);
-	platform_driver_unregister(&wcnss_driver);
-}
-module_exit(wcnss_exit);
+module_platform_driver(wcnss_driver);
 
 MODULE_DESCRIPTION("Qualcomm Peripheral Image Loader for Wireless Subsystem");
 MODULE_LICENSE("GPL v2");