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

[Sui Jingfeng]

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.jingf...@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