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From:   Bryan O'Donoghue <bryan.odonoghue@linaro.org>
To:     hverkuil-cisco@xs4all.nl, laurent.pinchart@ideasonboard.com,
        rfoss@kernel.org, todor.too@gmail.com, andersson@kernel.org,
        konrad.dybcio@linaro.org, mchehab@kernel.org
Cc:     linux-media@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, bryan.odonoghue@linaro.org
Subject: [PATCH v2 5/5] media: qcom: camss: Add support for named power-domains
Date:   Thu, 26 Oct 2023 16:50:42 +0100
Message-ID: <20231026155042.551731-6-bryan.odonoghue@linaro.org>
In-Reply-To: <20231026155042.551731-1-bryan.odonoghue@linaro.org>
References: <20231026155042.551731-1-bryan.odonoghue@linaro.org>
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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 declration 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.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
 drivers/media/platform/qcom/camss/camss-vfe.c | 24 ++++++++++++++++-
 drivers/media/platform/qcom/camss/camss.c     | 26 +++++++++++++++----
 drivers/media/platform/qcom/camss/camss.h     |  2 ++
 3 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c b/drivers/media/platform/qcom/camss/camss-vfe.c
index ebd5da6ad3f2f..cb48723efd8a0 100644
--- a/drivers/media/platform/qcom/camss/camss-vfe.c
+++ b/drivers/media/platform/qcom/camss/camss-vfe.c
@@ -1381,7 +1381,29 @@ 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)) {
 			ret = PTR_ERR(vfe->genpd);
diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
index 03e955c7a7e4c..837bab28d40e2 100644
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -1514,12 +1514,28 @@ static int camss_configure_pd(struct camss *camss)
 		return 0;
 
 	/*
-	 * VFE power domains are in the beginning of the list, and while all
-	 * power domains should be attached, only if TITAN_TOP power domain is
-	 * found in the list, it should be linked over here.
+	 * If a power-domain name is defined try to use it.
+	 * It is possible we are running a new kernel with an old dtb so
+	 * fallback to indexes even if a pd_name is defined but not found.
 	 */
-	camss->genpd = dev_pm_domain_attach_by_id(camss->dev, camss->genpd_num - 1);
-	if (IS_ERR(camss->genpd)) {
+	if (camss->res->pd_name) {
+		camss->genpd = dev_pm_domain_attach_by_name(camss->dev,
+							    camss->res->pd_name);
+		if (IS_ERR(camss->genpd)) {
+			ret = PTR_ERR(camss->genpd);
+			goto fail_pm;
+		}
+	}
+
+	if (!camss->genpd) {
+		/*
+		 * Legacy magic index. TITAN_TOP GDSC must be the last
+		 * item in the power-domain list.
+		 */
+		camss->genpd = dev_pm_domain_attach_by_id(camss->dev,
+							  camss->genpd_num - 1);
+	}
+	if (IS_ERR_OR_NULL(camss->genpd)) {
 		ret = PTR_ERR(camss->genpd);
 		goto fail_pm;
 	}
diff --git a/drivers/media/platform/qcom/camss/camss.h b/drivers/media/platform/qcom/camss/camss.h
index 1ba824a2cb76c..cd8186fe1797b 100644
--- a/drivers/media/platform/qcom/camss/camss.h
+++ b/drivers/media/platform/qcom/camss/camss.h
@@ -48,6 +48,7 @@ struct camss_subdev_resources {
 	u32 clock_rate[CAMSS_RES_MAX][CAMSS_RES_MAX];
 	char *reg[CAMSS_RES_MAX];
 	char *interrupt[CAMSS_RES_MAX];
+	char *pd_name;
 	u8 line_num;
 	bool has_pd;
 	const void *ops;
@@ -84,6 +85,7 @@ enum icc_count {
 
 struct camss_resources {
 	enum camss_version version;
+	const char *pd_name;
 	const struct camss_subdev_resources *csiphy_res;
 	const struct camss_subdev_resources *csid_res;
 	const struct camss_subdev_resources *ispif_res;
-- 
2.42.0