media: qcom: camss: Add support for named power-domains

Right now we use fixed indexes to assign power-domains, with a
requirement for the TOP GDSC to come last in the list.

Adding support for named power-domains means the declaration in the dtsi
can come in any order.

After this change we continue to support the old indexing - if a SoC
resource declaration or the in-use dtb doesn't declare power-domain names
we fall back to the default legacy indexing.

From this point on though new SoC additions should contain named
power-domains, eventually we will drop support for legacy indexing.

Tested-by: Matti Lehtimäki <matti.lehtimaki@gmail.com>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c b/drivers/media/platform/qcom/camss/camss-vfe.c
index 60286dac60e0..b2f91c00acaf 100644
--- a/drivers/media/platform/qcom/camss/camss-vfe.c
+++ b/drivers/media/platform/qcom/camss/camss-vfe.c
@@ -1380,7 +1380,29 @@ int msm_vfe_subdev_init(struct camss *camss, struct vfe_device *vfe,
 	if (!res->line_num)
 		return -EINVAL;
 
-	if (res->has_pd) {
+	/* Power domain */
+
+	if (res->pd_name) {
+		vfe->genpd = dev_pm_domain_attach_by_name(camss->dev,
+							  res->pd_name);
+		if (IS_ERR(vfe->genpd)) {
+			ret = PTR_ERR(vfe->genpd);
+			return ret;
+		}
+	}
+
+	if (!vfe->genpd && res->has_pd) {
+		/*
+		 * Legacy magic index.
+		 * Requires
+		 * power-domain = <VFE_X>,
+		 *                <VFE_Y>,
+		 *                <TITAN_TOP>
+		 * id must correspondng to the index of the VFE which must
+		 * come before the TOP GDSC. VFE Lite has no individually
+		 * collapasible domain which is why id < vfe_num is a valid
+		 * check.
+		 */
 		vfe->genpd = dev_pm_domain_attach_by_id(camss->dev, id);
 		if (IS_ERR(vfe->genpd))
 			return PTR_ERR(vfe->genpd);