[PATCH 3/3] drm/ingenic: Add support for reserved memory

[Paul Cercueil]

Add support for static memory reserved from Device Tree. Since we're
using GEM buffers backed by CMA, it is interesting to have an option to
specify the CMA area where the GEM buffers will be allocated.

Signed-off-by: Paul Cercueil <paul at crapouillou.net>
---
 drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
index aa32660033d2..44b0d029095e 100644
--- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
+++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of_device.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 
@@ -827,6 +828,11 @@ static void ingenic_drm_unbind_all(void *d)
 	component_unbind_all(priv->dev, &priv->drm);
 }
 
+static void __maybe_unused ingenic_drm_release_rmem(void *d)
+{
+	of_reserved_mem_device_release(d);
+}
+
 static int ingenic_drm_bind(struct device *dev, bool has_components)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -848,6 +854,19 @@ static int ingenic_drm_bind(struct device *dev, bool has_components)
 		return -EINVAL;
 	}
 
+	if (IS_ENABLED(CONFIG_OF_RESERVED_MEM)) {
+		ret = of_reserved_mem_device_init(dev);
+
+		if (ret && ret != -ENODEV)
+			return dev_err_probe(dev, ret, "Failed to get reserved memory\n");
+
+		if (ret != -ENODEV) {
+			ret = devm_add_action_or_reset(dev, ingenic_drm_release_rmem, dev);
+			if (ret)
+				return ret;
+		}
+	}
+
 	priv = devm_drm_dev_alloc(dev, &ingenic_drm_driver_data,
 				  struct ingenic_drm, drm);
 	if (IS_ERR(priv))
-- 
2.28.0