[etnaviv-next v14 7/8] drm/etnaviv: Allow creating subdevices and pass platform specific data

[Sui Jingfeng <sui.jingfeng@linux.dev>]

Because some hardware are too complex to be managed by a monolithic driver,
a split of the functionality into child devices can helps to achieve better
modularity.

We will use this function to create subdevice as a repensentation of a
single hardware ip block, so that the same modular approach that works
for ARM-SoC can also works for PCIe cards.

Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
---
 drivers/gpu/drm/etnaviv/etnaviv_drv.c | 33 +++++++++++++++++++++++----
 drivers/gpu/drm/etnaviv/etnaviv_drv.h |  9 ++++++++
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
index 863faac2ea19..dc3556aad134 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
@@ -670,16 +670,36 @@ static struct platform_driver etnaviv_platform_driver = {
 	},
 };
 
-static int etnaviv_create_platform_device(const char *name,
-					  struct platform_device **ppdev)
+int etnaviv_create_platform_device(struct device *parent,
+				   const char *name, int id,
+				   struct resource *pres,
+				   void *data,
+				   struct platform_device **ppdev)
 {
 	struct platform_device *pdev;
 	int ret;
 
-	pdev = platform_device_alloc(name, PLATFORM_DEVID_NONE);
+	pdev = platform_device_alloc(name, id);
 	if (!pdev)
 		return -ENOMEM;
 
+	pdev->dev.parent = parent;
+
+	if (pres) {
+		ret = platform_device_add_resources(pdev, pres, 1);
+		if (ret) {
+			platform_device_put(pdev);
+			return ret;
+		}
+	}
+
+	if (data) {
+		void *pdata = kmalloc(sizeof(void *), GFP_KERNEL);
+
+		*(void **)pdata = data;
+		pdev->dev.platform_data = pdata;
+	}
+
 	ret = platform_device_add(pdev);
 	if (ret) {
 		platform_device_put(pdev);
@@ -691,7 +711,7 @@ static int etnaviv_create_platform_device(const char *name,
 	return 0;
 }
 
-static void etnaviv_destroy_platform_device(struct platform_device **ppdev)
+void etnaviv_destroy_platform_device(struct platform_device **ppdev)
 {
 	struct platform_device *pdev = *ppdev;
 
@@ -728,7 +748,10 @@ static int __init etnaviv_init(void)
 	if (np) {
 		of_node_put(np);
 
-		ret = etnaviv_create_platform_device("etnaviv", &etnaviv_drm);
+		ret = etnaviv_create_platform_device(NULL, "etnaviv",
+						     PLATFORM_DEVID_NONE,
+						     NULL, NULL,
+						     &etnaviv_drm);
 		if (ret)
 			goto unregister_platform_driver;
 	}
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
index 4b59fdb457b7..4612843ff9f6 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
@@ -9,6 +9,7 @@
 #include <linux/io.h>
 #include <linux/list.h>
 #include <linux/mm_types.h>
+#include <linux/platform_device.h>
 #include <linux/sizes.h>
 #include <linux/time64.h>
 #include <linux/types.h>
@@ -98,6 +99,14 @@ bool etnaviv_cmd_validate_one(struct etnaviv_gpu *gpu,
 	u32 *stream, unsigned int size,
 	struct drm_etnaviv_gem_submit_reloc *relocs, unsigned int reloc_size);
 
+int etnaviv_create_platform_device(struct device *parent,
+				   const char *name, int id,
+				   struct resource *pres,
+				   void *data,
+				   struct platform_device **ppdev);
+
+void etnaviv_destroy_platform_device(struct platform_device **ppdev);
+
 #ifdef CONFIG_DEBUG_FS
 void etnaviv_gem_describe_objects(struct etnaviv_drm_private *priv,
 	struct seq_file *m);
-- 
2.34.1