[PATCH v5 1/3] media: venus: Add support for static video encoder/decoder declarations

[Bryan O'Donoghue]

Add resource structure data and probe() logic to support static
declarations of encoder and decoder.

Right now we rely on video encoder/decoder selection happening in the dtb
but, this goes against the remit of device tree which is supposed to
describe hardware, not select functional logic in Linux drivers.

Provide two strings in the venus resource structure enc_nodename and
dec_nodename.

When set the venus driver will create an OF entry in-memory consistent
with:

dec_nodename {
    compat = "video-decoder";
};

and/or

enc_nodename {
    compat = "video-encoder";
};

This will allow us to reuse the existing driver scheme of relying on compat
names maintaining compatibility with old dtb files.

dec_nodename can be "video-decoder" or "video0"
enc_nodename can be "video-encoder" or "video1"

This change relies on of_changeset() API as a result select OF_DYNAMIC will
be added to venus/Kconfig

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
---
 drivers/media/platform/qcom/venus/Kconfig |  1 +
 drivers/media/platform/qcom/venus/core.c  | 94 ++++++++++++++++++++++++++++++-
 drivers/media/platform/qcom/venus/core.h  |  4 ++
 3 files changed, 98 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/qcom/venus/Kconfig b/drivers/media/platform/qcom/venus/Kconfig
index bfd50e8f34219db8a1de7960d7ea93b20db2982a..bc2e410b29cb415a36540a4f98709eae44f4ec35 100644
--- a/drivers/media/platform/qcom/venus/Kconfig
+++ b/drivers/media/platform/qcom/venus/Kconfig
@@ -3,6 +3,7 @@ config VIDEO_QCOM_VENUS
 	depends on V4L_MEM2MEM_DRIVERS
 	depends on VIDEO_DEV && QCOM_SMEM
 	depends on (ARCH_QCOM && IOMMU_DMA) || COMPILE_TEST
+	select OF_DYNAMIC if ARCH_QCOM
 	select QCOM_MDT_LOADER if ARCH_QCOM
 	select QCOM_SCM
 	select VIDEOBUF2_DMA_CONTIG
diff --git a/drivers/media/platform/qcom/venus/core.c b/drivers/media/platform/qcom/venus/core.c
index 4e26b18790537885a77d66c1917a4e7a146eaf57..88dfa9f240dc6d18a7f58dc06b1bf10274b7121e 100644
--- a/drivers/media/platform/qcom/venus/core.c
+++ b/drivers/media/platform/qcom/venus/core.c
@@ -286,6 +286,89 @@ static irqreturn_t venus_isr_thread(int irq, void *dev_id)
 	return ret;
 }
 
+#if defined(CONFIG_OF_DYNAMIC)
+static int venus_add_video_core(struct venus_core *core, const char *node_name,
+				const char *compat)
+{
+	struct of_changeset *ocs = core->ocs;
+	struct device *dev = core->dev;
+	struct device_node *np, *enp;
+	int ret;
+
+	if (!node_name)
+		return 0;
+
+	enp = of_find_node_by_name(dev->of_node, node_name);
+	if (enp) {
+		of_node_put(enp);
+		return 0;
+	}
+
+	np = of_changeset_create_node(ocs, dev->of_node, node_name);
+	if (!np) {
+		dev_err(dev, "Unable to create new node\n");
+		return -ENODEV;
+	}
+
+	ret = of_changeset_add_prop_string(ocs, np, "compatible", compat);
+	if (ret)
+		dev_err(dev, "unable to add %s\n", compat);
+
+	of_node_put(np);
+
+	return ret;
+}
+
+static int venus_add_dynamic_nodes(struct venus_core *core)
+{
+	struct device *dev = core->dev;
+	int ret;
+
+	core->ocs = kmalloc(sizeof(*core->ocs), GFP_KERNEL);
+	if (!core->ocs)
+		return -ENOMEM;
+
+	of_changeset_init(core->ocs);
+
+	ret = venus_add_video_core(core, core->res->dec_nodename, "venus-decoder");
+	if (ret)
+		goto err;
+
+	ret = venus_add_video_core(core, core->res->enc_nodename, "venus-encoder");
+	if (ret)
+		goto err;
+
+	ret = of_changeset_apply(core->ocs);
+	if (ret) {
+		dev_err(dev, "applying changeset fail ret %d\n", ret);
+		goto err;
+	}
+
+	return 0;
+err:
+	of_changeset_destroy(core->ocs);
+	kfree(core->ocs);
+	core->ocs = NULL;
+	return ret;
+}
+
+static void venus_remove_dynamic_nodes(struct venus_core *core)
+{
+	if (core->ocs) {
+		of_changeset_revert(core->ocs);
+		of_changeset_destroy(core->ocs);
+		kfree(core->ocs);
+	}
+}
+#else
+static int venus_add_dynamic_nodes(struct venus_core *core)
+{
+	return 0;
+}
+
+static void venus_remove_dynamic_nodes(struct venus_core *core) {}
+#endif
+
 static int venus_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -365,9 +448,14 @@ static int venus_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto err_runtime_disable;
 
+	if (core->res->dec_nodename || core->res->enc_nodename) {
+		if (venus_add_dynamic_nodes(core))
+			goto err_runtime_disable;
+	}
+
 	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
 	if (ret)
-		goto err_runtime_disable;
+		goto err_remove_dynamic_nodes;
 
 	ret = venus_firmware_init(core);
 	if (ret)
@@ -411,6 +499,8 @@ static int venus_probe(struct platform_device *pdev)
 	venus_firmware_deinit(core);
 err_of_depopulate:
 	of_platform_depopulate(dev);
+err_remove_dynamic_nodes:
+	venus_remove_dynamic_nodes(core);
 err_runtime_disable:
 	pm_runtime_put_noidle(dev);
 	pm_runtime_disable(dev);
@@ -443,6 +533,8 @@ static void venus_remove(struct platform_device *pdev)
 
 	venus_firmware_deinit(core);
 
+	venus_remove_dynamic_nodes(core);
+
 	pm_runtime_put_sync(dev);
 	pm_runtime_disable(dev);
 
diff --git a/drivers/media/platform/qcom/venus/core.h b/drivers/media/platform/qcom/venus/core.h
index 27784fd7082c321222b23ca4b2902a04c49e19ca..306231b4f7d0201175974b4a42574f30d23e08f0 100644
--- a/drivers/media/platform/qcom/venus/core.h
+++ b/drivers/media/platform/qcom/venus/core.h
@@ -90,6 +90,8 @@ struct venus_resources {
 	u32 cp_nonpixel_start;
 	u32 cp_nonpixel_size;
 	const char *fwname;
+	const char *enc_nodename;
+	const char *dec_nodename;
 };
 
 enum venus_fmt {
@@ -171,6 +173,7 @@ struct venus_format {
  * @root:	debugfs root directory
  * @venus_ver:	the venus firmware version
  * @dump_core:	a flag indicating that a core dump is required
+ * @ocs:	OF changeset pointer
  */
 struct venus_core {
 	void __iomem *base;
@@ -235,6 +238,7 @@ struct venus_core {
 		u32 rev;
 	} venus_ver;
 	unsigned long dump_core;
+	struct of_changeset *ocs;
 };
 
 struct vdec_controls {

-- 
2.47.1