[PATCH v3 5/8] drm/simpledrm: Add support for system memory framebuffers
Thomas Zimmermann
tzimmermann at suse.de
Fri Nov 18 14:11:23 UTC 2022
Hi
Am 17.11.22 um 19:40 schrieb Thierry Reding:
> From: Thierry Reding <treding at nvidia.com>
>
> 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.
>
> Signed-off-by: Thierry Reding <treding at nvidia.com>
> ---
> Changes in v3:
> - simplify memory code and move back to simpledrm_device_create()
> - extract screen_base iosys_map fix into separate patch
>
> Changes in v2:
> - make screen base a struct iosys_map to avoid sparse warnings
>
> drivers/gpu/drm/tiny/simpledrm.c | 99 ++++++++++++++++++++++++--------
> 1 file changed, 75 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c
> index 3673a42e4bf4..7f39bc58da52 100644
> --- a/drivers/gpu/drm/tiny/simpledrm.c
> +++ b/drivers/gpu/drm/tiny/simpledrm.c
> @@ -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
> */
> @@ -623,8 +649,7 @@ 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;
> @@ -676,6 +701,9 @@ 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);
> @@ -698,32 +726,55 @@ 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);
> + }
>
> - 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;
> - }
> + drm_info(dev, "using system memory framebuffer at %pr\n", mem);
drm_dbg() please.
>
> - screen_base = devm_ioremap_wc(&pdev->dev, mem->start, resource_size(mem));
> - if (!screen_base)
> - return ERR_PTR(-ENOMEM);
> + screen_base = devm_memremap(dev->dev, mem->start, resource_size(mem), MEMREMAP_WB);
> + 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);
>
> - iosys_map_set_vaddr_iomem(&sdev->screen_base, 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: %d\n", &res, ret);
> + return ERR_PTR(ret);
> + }
> +
> + drm_info(dev, "using I/O memory framebuffer at %pr\n", res);
drm_dbg()
With the small fixes, please add
Reviewed-by: Thomas Zimmermann <tzimmermann at suse.de>
Best regards
Thomas
> +
> + 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
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev
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