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drm/simpledrm: Add support for system memory framebuffers

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Simple framebuffers can be set up in system memory, which cannot be
requested and/or I/O remapped using the I/O resource helpers. Add a
separate code path that obtains system memory framebuffers from the
reserved memory region referenced in the memory-region property.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230120173103.4002342-6-thierry.reding@gmail.com
This commit is contained in:
Thierry Reding 2023-01-20 18:31:00 +01:00
parent fa904b4cbc
commit 9a10c7e651
1 changed files with 77 additions and 26 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

103
drivers/gpu/drm/tiny/simpledrm.c
View file

@ -3,6 +3,7 @@
#include <linux/clk.h>
#include <linux/of_clk.h>
#include <linux/minmax.h>
#include <linux/of_address.h>
#include <linux/platform_data/simplefb.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
@ -184,6 +185,31 @@ simplefb_get_format_of(struct drm_device *dev, struct device_node *of_node)
return simplefb_get_validated_format(dev, format);
}
static struct resource *
simplefb_get_memory_of(struct drm_device *dev, struct device_node *of_node)
{
struct device_node *np;
struct resource *res;
int err;
np = of_parse_phandle(of_node, "memory-region", 0);
if (!np)
return NULL;
res = devm_kzalloc(dev->dev, sizeof(*res), GFP_KERNEL);
if (!res)
return ERR_PTR(-ENOMEM);
err = of_address_to_resource(np, 0, res);
if (err)
return ERR_PTR(err);
if (of_get_property(of_node, "reg", NULL))
drm_warn(dev, "preferring \"memory-region\" over \"reg\" property\n");
return res;
}
/*
* Simple Framebuffer device
*/
@ -604,8 +630,7 @@ static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv,
struct drm_device *dev;
int width, height, stride;
const struct drm_format_info *format;
struct resource *res, *mem;
void __iomem *screen_base;
struct resource *res, *mem = NULL;
struct drm_plane *primary_plane;
struct drm_crtc *crtc;
struct drm_encoder *encoder;
@ -657,6 +682,9 @@ static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv,
format = simplefb_get_format_of(dev, of_node);
if (IS_ERR(format))
return ERR_CAST(format);
mem = simplefb_get_memory_of(dev, of_node);
if (IS_ERR(mem))
return ERR_CAST(mem);
} else {
drm_err(dev, "no simplefb configuration found\n");
return ERR_PTR(-ENODEV);
@ -679,33 +707,56 @@ static struct simpledrm_device *simpledrm_device_create(struct drm_driver *drv,
* Memory management
*/
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return ERR_PTR(-EINVAL);
if (mem) {
void *screen_base;
ret = devm_aperture_acquire_from_firmware(dev, res->start, resource_size(res));
if (ret) {
drm_err(dev, "could not acquire memory range %pr: error %d\n", res, ret);
return ERR_PTR(ret);
ret = devm_aperture_acquire_from_firmware(dev, mem->start, resource_size(mem));
if (ret) {
drm_err(dev, "could not acquire memory range %pr: %d\n", mem, ret);
return ERR_PTR(ret);
}
drm_dbg(dev, "using system memory framebuffer at %pr\n", mem);
screen_base = devm_memremap(dev->dev, mem->start, resource_size(mem), MEMREMAP_WC);
if (!screen_base)
return ERR_PTR(-ENOMEM);
iosys_map_set_vaddr(&sdev->screen_base, screen_base);
} else {
void __iomem *screen_base;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return ERR_PTR(-EINVAL);
ret = devm_aperture_acquire_from_firmware(dev, res->start, resource_size(res));
if (ret) {
drm_err(dev, "could not acquire memory range %pr: %d\n", &res, ret);
return ERR_PTR(ret);
}
drm_dbg(dev, "using I/O memory framebuffer at %pr\n", res);
mem = devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
drv->name);
if (!mem) {
/*
* We cannot make this fatal. Sometimes this comes from magic
* spaces our resource handlers simply don't know about. Use
* the I/O-memory resource as-is and try to map that instead.
*/
drm_warn(dev, "could not acquire memory region %pr\n", res);
mem = res;
}
screen_base = devm_ioremap_wc(&pdev->dev, mem->start, resource_size(mem));
if (!screen_base)
return ERR_PTR(-ENOMEM);
iosys_map_set_vaddr_iomem(&sdev->screen_base, screen_base);
}
mem = devm_request_mem_region(&pdev->dev, res->start, resource_size(res), drv->name);
if (!mem) {
/*
* We cannot make this fatal. Sometimes this comes from magic
* spaces our resource handlers simply don't know about. Use
* the I/O-memory resource as-is and try to map that instead.
*/
drm_warn(dev, "could not acquire memory region %pr\n", res);
mem = res;
}
screen_base = devm_ioremap_wc(&pdev->dev, mem->start, resource_size(mem));
if (!screen_base)
return ERR_PTR(-ENOMEM);
iosys_map_set_vaddr_iomem(&sdev->screen_base, screen_base);
/*
* Modesetting
*/