On Wed, May 18, 2022 at 10:11:03PM +0100, Mark Cave-Ayland wrote:
> On 18/05/2022 19:30, Thomas Zimmermann wrote:
>
> > Open Firmware provides basic display output via the 'display' node.
> > DT platform code already provides a device that represents the node's
> > framebuffer. Add a DRM driver for the device. The display mode and
> > color format is pre-initialized by the system's firmware. Runtime
> > modesetting via DRM is not possible. The display is useful during
> > early boot stages or as error fallback.
> >
> > Similar functionality is already provided by fbdev's offb driver,
> > which is insufficient for modern userspace. The old driver includes
> > support for BootX device tree, which can be found on old 32-bit
> > PowerPC Macintosh systems. If these are still in use, the
> > functionality can be added to ofdrm or implemented in a new
> > driver. As with simepldrm, the fbdev driver cannot be selected is
> > ofdrm is already enabled.
> >
> > Two noteable points about the driver:
> >
> > * Reading the framebuffer aperture from the device tree is not
> > reliable on all systems. Ofdrm takes the heuristics and a comment
> > from offb to pick the correct range.
> >
> > * No resource management may be tied to the underlying PCI device.
> > Otherwise the handover to the native driver will fail with a resource
> > conflict. PCI management is therefore done as part of the platform
> > device's cleanup.
> >
> > The driver has been tested on qemu's ppc64le emulation. The device
> > hand-over has been tested with bochs.
>
> Thanks for working on this! Have you tried it on qemu-system-sparc and
> qemu-system-sparc64 at all? At least under QEMU I'd expect it to work for
> these platforms too, unless there is a particular dependency on PCI. A
There is an implicit dependency on PCI, and it won't work because it
depends on PPC:
depends on DRM && MMU && PPC
this is what the offb has, too.
I am wondering what is the driver for OF based framebuffer on sparc and
arm but offb clearly isn't with its dependency on PPC.
Thanks
Michal
> couple of comments inline below:
>
> > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> > ---
> > MAINTAINERS | 1 +
> > drivers/gpu/drm/tiny/Kconfig | 12 +
> > drivers/gpu/drm/tiny/Makefile | 1 +
> > drivers/gpu/drm/tiny/ofdrm.c | 748 ++++++++++++++++++++++++++++++++++
> > drivers/video/fbdev/Kconfig | 1 +
> > 5 files changed, 763 insertions(+)
> > create mode 100644 drivers/gpu/drm/tiny/ofdrm.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 43d833273ae9..090cbe1aa5e3 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -6395,6 +6395,7 @@ L: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > S: Maintained
> > T: git git://anongit.freedesktop.org/drm/drm-misc
> > F: drivers/gpu/drm/drm_aperture.c
> > +F: drivers/gpu/drm/tiny/ofdrm.c
> > F: drivers/gpu/drm/tiny/simpledrm.c
> > F: include/drm/drm_aperture.h
> > diff --git a/drivers/gpu/drm/tiny/Kconfig b/drivers/gpu/drm/tiny/Kconfig
> > index 627d637a1e7e..0bc54af42e7f 100644
> > --- a/drivers/gpu/drm/tiny/Kconfig
> > +++ b/drivers/gpu/drm/tiny/Kconfig
> > @@ -51,6 +51,18 @@ config DRM_GM12U320
> > This is a KMS driver for projectors which use the GM12U320 chipset
> > for video transfer over USB2/3, such as the Acer C120 mini projector.
> > +config DRM_OFDRM
> > + tristate "Open Firmware display driver"
> > + depends on DRM && MMU && PPC
> > + select DRM_GEM_SHMEM_HELPER
> > + select DRM_KMS_HELPER
> > + help
> > + DRM driver for Open Firmware framebuffers.
> > +
> > + This driver assumes that the display hardware has been initialized
> > + by the Open Firmware before the kernel boots. Scanout buffer, size,
> > + and display format must be provided via device tree.
> > +
> > config DRM_PANEL_MIPI_DBI
> > tristate "DRM support for MIPI DBI compatible panels"
> > depends on DRM && SPI
> > diff --git a/drivers/gpu/drm/tiny/Makefile b/drivers/gpu/drm/tiny/Makefile
> > index 1d9d6227e7ab..76dde89a044b 100644
> > --- a/drivers/gpu/drm/tiny/Makefile
> > +++ b/drivers/gpu/drm/tiny/Makefile
> > @@ -4,6 +4,7 @@ obj-$(CONFIG_DRM_ARCPGU) += arcpgu.o
> > obj-$(CONFIG_DRM_BOCHS) += bochs.o
> > obj-$(CONFIG_DRM_CIRRUS_QEMU) += cirrus.o
> > obj-$(CONFIG_DRM_GM12U320) += gm12u320.o
> > +obj-$(CONFIG_DRM_OFDRM) += ofdrm.o
> > obj-$(CONFIG_DRM_PANEL_MIPI_DBI) += panel-mipi-dbi.o
> > obj-$(CONFIG_DRM_SIMPLEDRM) += simpledrm.o
> > obj-$(CONFIG_TINYDRM_HX8357D) += hx8357d.o
> > diff --git a/drivers/gpu/drm/tiny/ofdrm.c b/drivers/gpu/drm/tiny/ofdrm.c
> > new file mode 100644
> > index 000000000000..aca715b36179
> > --- /dev/null
> > +++ b/drivers/gpu/drm/tiny/ofdrm.c
> > @@ -0,0 +1,748 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +
> > +#include <linux/pci.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include <drm/drm_aperture.h>
> > +#include <drm/drm_atomic_state_helper.h>
> > +#include <drm/drm_connector.h>
> > +#include <drm/drm_damage_helper.h>
> > +#include <drm/drm_device.h>
> > +#include <drm/drm_drv.h>
> > +#include <drm/drm_fb_helper.h>
> > +#include <drm/drm_format_helper.h>
> > +#include <drm/drm_gem_atomic_helper.h>
> > +#include <drm/drm_gem_framebuffer_helper.h>
> > +#include <drm/drm_gem_shmem_helper.h>
> > +#include <drm/drm_managed.h>
> > +#include <drm/drm_modeset_helper_vtables.h>
> > +#include <drm/drm_probe_helper.h>
> > +#include <drm/drm_simple_kms_helper.h>
> > +
> > +
> > +#define DRIVER_NAME "ofdrm"
> > +#define DRIVER_DESC "DRM driver for OF platform devices"
> > +#define DRIVER_DATE "20220501"
> > +#define DRIVER_MAJOR 1
> > +#define DRIVER_MINOR 0
> > +
> > +/*
> > + * Assume a monitor resolution of 96 dpi to
> > + * get a somewhat reasonable screen size.
> > + */
> > +#define RES_MM(d) \
> > + (((d) * 254ul) / (96ul * 10ul))
> > +
> > +#define OFDRM_MODE(hd, vd) \
> > + DRM_SIMPLE_MODE(hd, vd, RES_MM(hd), RES_MM(vd))
> > +
> > +/*
> > + * Helpers for display nodes
> > + */
> > +
> > +static int display_get_validated_int(struct drm_device *dev, const char *name, uint32_t value)
> > +{
> > + if (value > INT_MAX) {
> > + drm_err(dev, "invalid framebuffer %s of %u\n", name, value);
> > + return -EINVAL;
> > + }
> > + return (int)value;
> > +}
> > +
> > +static int display_get_validated_int0(struct drm_device *dev, const char *name, uint32_t value)
> > +{
> > + if (!value) {
> > + drm_err(dev, "invalid framebuffer %s of %u\n", name, value);
> > + return -EINVAL;
> > + }
> > + return display_get_validated_int(dev, name, value);
> > +}
> > +
> > +static const struct drm_format_info *display_get_validated_format(struct drm_device *dev,
> > + u32 depth)
> > +{
> > + const struct drm_format_info *info;
> > + u32 format;
> > +
> > + switch (depth) {
> > + case 8:
> > + format = drm_mode_legacy_fb_format(8, 8);
> > + break;
> > + case 15:
> > + case 16:
> > + format = drm_mode_legacy_fb_format(16, depth);
> > + break;
> > + case 32:
> > + format = drm_mode_legacy_fb_format(32, 24);
> > + break;
> > + default:
> > + drm_err(dev, "unsupported framebuffer depth %u\n", depth);
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > + info = drm_format_info(format);
> > + if (!info) {
> > + drm_err(dev, "cannot find framebuffer format for depth %u\n", depth);
> > + return ERR_PTR(-EINVAL);
> > + }
> > +
> > + return info;
> > +}
> > +
> > +static int display_read_u32_of(struct drm_device *dev, struct device_node *of_node,
> > + const char *name, u32 *value)
> > +{
> > + int ret = of_property_read_u32(of_node, name, value);
> > +
> > + if (ret)
> > + drm_err(dev, "cannot parse framebuffer %s: error %d\n", name, ret);
> > + return ret;
> > +}
> > +
> > +static int display_get_width_of(struct drm_device *dev, struct device_node *of_node)
> > +{
> > + u32 width;
> > + int ret = display_read_u32_of(dev, of_node, "width", &width);
> > +
> > + if (ret)
> > + return ret;
> > + return display_get_validated_int0(dev, "width", width);
> > +}
> > +
> > +static int display_get_height_of(struct drm_device *dev, struct device_node *of_node)
> > +{
> > + u32 height;
> > + int ret = display_read_u32_of(dev, of_node, "height", &height);
> > +
> > + if (ret)
> > + return ret;
> > + return display_get_validated_int0(dev, "height", height);
> > +}
> > +
> > +static int display_get_linebytes_of(struct drm_device *dev, struct device_node *of_node)
> > +{
> > + u32 linebytes;
> > + int ret = display_read_u32_of(dev, of_node, "linebytes", &linebytes);
> > +
> > + if (ret)
> > + return ret;
> > + return display_get_validated_int(dev, "linebytes", linebytes);
> > +}
> > +
> > +static const struct drm_format_info *display_get_format_of(struct drm_device *dev,
> > + struct device_node *of_node)
> > +{
> > + u32 depth;
> > + int ret = display_read_u32_of(dev, of_node, "depth", &depth);
> > +
> > + if (ret)
> > + return ERR_PTR(ret);
> > + return display_get_validated_format(dev, depth);
> > +}
> > +
> > +static u64 display_get_address_of(struct drm_device *dev, struct device_node *of_node)
> > +{
> > + u32 address;
> > + int ret;
> > +
> > + /*
> > + * Not all devices provide an address property, it's not
> > + * a bug if this fails. The driver will try to find the
> > + * framebuffer base address from the device's memory regions.
> > + */
> > + ret = of_property_read_u32(of_node, "address", &address);
> > + if (ret)
> > + return OF_BAD_ADDR;
> > +
> > + return address;
> > +}
> > +
> > +#if defined(CONFIG_PCI)
> > +static struct pci_dev *display_get_pci_dev_of(struct drm_device *dev, struct device_node *of_node)
> > +{
> > + const __be32 *vendor_p, *device_p;
> > + u32 vendor, device;
> > + struct pci_dev *pcidev;
> > +
> > + vendor_p = of_get_property(of_node, "vendor-id", NULL);
> > + if (!vendor_p)
> > + return ERR_PTR(-ENODEV);
> > + vendor = be32_to_cpup(vendor_p);
> > +
> > + device_p = of_get_property(of_node, "device-id", NULL);
> > + if (!device_p)
> > + return ERR_PTR(-ENODEV);
> > + device = be32_to_cpup(device_p);
> > +
> > + pcidev = pci_get_device(vendor, device, NULL);
> > + if (!pcidev)
> > + return ERR_PTR(-ENODEV);
> > +
> > + return pcidev;
> > +}
> > +#else
> > +static struct pci_dev *display_get_pci_dev_of(struct drm_device *dev, struct device_node *of_node)
> > +{
> > + return ERR_PTR(-ENODEV);
> > +}
> > +#endif
> > +
> > +/*
> > + * Open Firmware display device
> > + */
> > +
> > +struct ofdrm_device {
> > + struct drm_device dev;
> > + struct platform_device *pdev;
> > +
> > + /* OF display settings */
> > + struct drm_display_mode mode;
> > + const struct drm_format_info *format;
> > + unsigned int pitch;
> > + resource_size_t fb_base;
> > + resource_size_t fb_size;
> > +
> > + /* memory management */
> > + struct resource *mem;
> > + void __iomem *screen_base;
> > +
> > + /* modesetting */
> > + uint32_t formats[8];
> > + size_t nformats;
> > + struct drm_connector connector;
> > + struct drm_simple_display_pipe pipe;
> > +};
> > +
> > +static struct ofdrm_device *ofdrm_device_of_dev(struct drm_device *dev)
> > +{
> > + return container_of(dev, struct ofdrm_device, dev);
> > +}
> > +
> > +/*
> > + * OF display settings
> > + */
> > +
> > +static void ofdrm_pci_release(void *data)
> > +{
> > + struct pci_dev *pcidev = data;
> > +
> > + pci_disable_device(pcidev);
> > +}
> > +
> > +static struct drm_display_mode ofdrm_mode(unsigned int width, unsigned int height)
> > +{
> > + struct drm_display_mode mode = { OFDRM_MODE(width, height) };
> > +
> > + mode.clock = mode.hdisplay * mode.vdisplay * 60 / 1000 /* kHz */;
> > + drm_mode_set_name(&mode);
> > +
> > + return mode;
> > +}
> > +
> > +static struct resource *ofdrm_find_fb_resource(struct ofdrm_device *odev,
> > + struct resource *fb_res)
> > +{
> > + struct platform_device *pdev = to_platform_device(odev->dev.dev);
> > + struct resource *res, *max_res = NULL;
> > + u32 i;
> > +
> > + for (i = 0; pdev->num_resources; ++i) {
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, i);
> > + if (!res)
> > + break; /* all resources processed */
> > + if (resource_size(res) < resource_size(fb_res))
> > + continue; /* resource too small */
> > + if (fb_res->start && resource_contains(res, fb_res))
> > + return res; /* resource contains framebuffer */
> > + if (!max_res || resource_size(res) > resource_size(max_res))
> > + max_res = res; /* store largest resource as fallback */
> > + }
> > +
> > + return max_res;
> > +}
> > +
> > +static int ofdrm_device_init_fb(struct ofdrm_device *odev)
> > +{
> > + struct drm_device *dev = &odev->dev;
> > + struct platform_device *pdev = odev->pdev;
> > + struct device_node *of_node = pdev->dev.of_node;
> > + int width, height, linebytes;
> > + u64 address;
> > + const struct drm_format_info *format;
> > + struct pci_dev *pcidev;
> > + struct resource *res;
> > + int ret;
> > +
> > + width = display_get_width_of(dev, of_node);
> > + if (width < 0)
> > + return width;
> > + height = display_get_height_of(dev, of_node);
> > + if (height < 0)
> > + return height;
> > + linebytes = display_get_linebytes_of(dev, of_node);
> > + if (linebytes < 0)
> > + return linebytes;
> > + format = display_get_format_of(dev, of_node);
> > + if (IS_ERR(format))
> > + return PTR_ERR(format);
> > + address = display_get_address_of(dev, of_node);
> > +
> > + /*
> > + * Never use pcim_ or other managed helpers on the returned PCI
> > + * device. Otherwise, probing the native driver will fail for
> > + * resource conflicts. PCI-device management has to be tied to
> > + * the lifetime of the platform device until the native driver
> > + * takes over.
> > + */
> > + pcidev = display_get_pci_dev_of(dev, of_node);
> > + if (!IS_ERR(pcidev)) {
> > + ret = pci_enable_device(pcidev);
> > + if (drm_WARN(dev, ret, "pci_enable_device(%s) failed: %d\n",
> > + dev_name(&pcidev->dev), ret))
> > + return ret;
> > + ret = devm_add_action_or_reset(&pdev->dev, ofdrm_pci_release, pcidev);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + odev->mode = ofdrm_mode(width, height);
> > + odev->format = format;
> > +
> > + if (linebytes)
> > + odev->pitch = linebytes;
> > + else
> > + odev->pitch = width * format->cpp[0];
> > +
> > + odev->fb_size = odev->pitch * height;
> > +
> > + /*
> > + * Try to figure out the address of the framebuffer. Unfortunately, Open
> > + * Firmware doesn't provide a standard way to do so. All we can do is a
> > + * dodgy heuristic that happens to work in practice.
>
> This isn't quite true: there is a Forth value named "frame-buffer-adr" which
> should be set to the physical screen base address for PCI and non-PCI cards.
> It is mentioned in both the IEEE-1275 specification (page 32) and according
> to OpenBIOS is also referenced by BootX:
> https://mail.coreboot.org/pipermail/openbios/2011-August/006617.html.
>
> > + * On most machines, the "address" property contains what we need, though
> > + * not on Matrox cards found in IBM machines. What appears to give good
> > + * results is to go through the PCI ranges and pick one that encloses the
> > + * "address" property. If none match, we pick the largest.
> > + */
>
> In my experience so far "frame-buffer-adr" is the definitive way to get the
> screen physical address, however you'll need to call the CIF interface in
> order to get the value. The cases where I've seen an "address" property in
> the display node is when the display has also been mapped to a virtual
> address, which may or may not be the same as the physical address. I suspect
> this optional virtual mapping may not be present by the time the ofdrm
> driver loads?
>
> > + if (address != OF_BAD_ADDR) {
> > + struct resource fb_res = DEFINE_RES_MEM(address, odev->fb_size);
> > +
> > + res = ofdrm_find_fb_resource(odev, &fb_res);
> > + if (!res)
> > + return -EINVAL;
> > + if (resource_contains(res, &fb_res))
> > + odev->fb_base = address;
> > + else
> > + odev->fb_base = res->start;
> > + } else {
> > + struct resource fb_res = DEFINE_RES_MEM(0u, odev->fb_size);
> > +
> > + res = ofdrm_find_fb_resource(odev, &fb_res);
> > + if (!res)
> > + return -EINVAL;
> > + odev->fb_base = res->start;
> > + }
> > +
> > + drm_dbg(dev, "display mode={" DRM_MODE_FMT "}\n", DRM_MODE_ARG(&odev->mode));
> > + drm_dbg(dev, "framebuffer format=%p4cc, size=%dx%d, linebytes=%d byte, address=0x%llx\n",
> > + &format->format, width, height, linebytes, address);
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Memory management
> > + */
> > +
> > +static int ofdrm_device_init_mm(struct ofdrm_device *odev)
> > +{
> > + struct drm_device *dev = &odev->dev;
> > + struct platform_device *pdev = odev->pdev;
> > + struct resource res = DEFINE_RES_MEM(odev->fb_base, round_up(odev->fb_size, PAGE_SIZE));
> > + struct resource *mem;
> > + void __iomem *screen_base;
> > + int ret;
> > +
> > + 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 ret;
> > + }
> > +
> > + mem = devm_request_mem_region(&pdev->dev, res.start, resource_size(&res),
> > + odev->dev.driver->name);
> > + if (!mem) {
> > + drm_warn(dev, "could not acquire memory region %pr\n", &res);
> > + return -ENOMEM;
> > + }
> > +
> > + drm_dbg(dev, "mapping framebuffer: %pr\n", mem);
> > +
> > + screen_base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
> > + if (drm_WARN_ON(dev, !screen_base))
> > + return -ENOMEM;
> > +
> > + odev->mem = mem;
> > + odev->screen_base = screen_base;
> > +
> > + drm_dbg(dev, "framebuffer at %pr, mapped at 0x%p\n", mem, screen_base);
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Modesetting
> > + */
> > +
> > +/*
> > + * Support all formats of OF display and maybe more; in order
> > + * of preference. The display's update function will do any
> > + * conversion necessary.
> > + *
> > + * TODO: Add blit helpers for remaining formats and uncomment
> > + * constants.
> > + */
> > +static const uint32_t ofdrm_default_formats[] = {
> > + DRM_FORMAT_XRGB8888,
> > + DRM_FORMAT_RGB565,
> > + //DRM_FORMAT_XRGB1555,
> > + DRM_FORMAT_C8,
> > +};
> > +
> > +static const uint64_t ofdrm_format_modifiers[] = {
> > + DRM_FORMAT_MOD_LINEAR,
> > + DRM_FORMAT_MOD_INVALID
> > +};
> > +
> > +static int ofdrm_connector_helper_get_modes(struct drm_connector *connector)
> > +{
> > + struct ofdrm_device *odev = ofdrm_device_of_dev(connector->dev);
> > + struct drm_display_mode *mode;
> > +
> > + mode = drm_mode_duplicate(connector->dev, &odev->mode);
> > + if (!mode)
> > + return 0;
> > +
> > + if (mode->name[0] == '\0')
> > + drm_mode_set_name(mode);
> > +
> > + mode->type |= DRM_MODE_TYPE_PREFERRED;
> > + drm_mode_probed_add(connector, mode);
> > +
> > + if (mode->width_mm)
> > + connector->display_info.width_mm = mode->width_mm;
> > + if (mode->height_mm)
> > + connector->display_info.height_mm = mode->height_mm;
> > +
> > + return 1;
> > +}
> > +
> > +static const struct drm_connector_helper_funcs ofdrm_connector_helper_funcs = {
> > + .get_modes = ofdrm_connector_helper_get_modes,
> > +};
> > +
> > +static const struct drm_connector_funcs ofdrm_connector_funcs = {
> > + .reset = drm_atomic_helper_connector_reset,
> > + .fill_modes = drm_helper_probe_single_connector_modes,
> > + .destroy = drm_connector_cleanup,
> > + .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> > + .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> > +};
> > +
> > +static int ofdrm_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
> > + const struct drm_display_mode *mode)
> > +{
> > + struct ofdrm_device *odev = ofdrm_device_of_dev(pipe->crtc.dev);
> > +
> > + if (mode->hdisplay != odev->mode.hdisplay &&
> > + mode->vdisplay != odev->mode.vdisplay)
> > + return MODE_ONE_SIZE;
> > + else if (mode->hdisplay != odev->mode.hdisplay)
> > + return MODE_ONE_WIDTH;
> > + else if (mode->vdisplay != odev->mode.vdisplay)
> > + return MODE_ONE_HEIGHT;
> > +
> > + return MODE_OK;
> > +}
> > +
> > +static void ofdrm_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
> > + struct drm_crtc_state *crtc_state,
> > + struct drm_plane_state *plane_state)
> > +{
> > + struct ofdrm_device *odev = ofdrm_device_of_dev(pipe->crtc.dev);
> > + struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
> > + struct drm_framebuffer *fb = plane_state->fb;
> > + void *vmap = shadow_plane_state->data[0].vaddr; /* TODO: Use mapping abstraction */
> > + struct drm_device *dev = &odev->dev;
> > + void __iomem *dst = odev->screen_base;
> > + struct drm_rect src_clip, dst_clip;
> > + int idx;
> > +
> > + if (!fb)
> > + return;
> > +
> > + drm_rect_fp_to_int(&src_clip, &plane_state->src);
> > +
> > + dst_clip = plane_state->dst;
> > + if (!drm_rect_intersect(&dst_clip, &src_clip))
> > + return;
> > +
> > + if (!drm_dev_enter(dev, &idx))
> > + return;
> > +
> > + dst += drm_fb_clip_offset(odev->pitch, odev->format, &dst_clip);
> > + drm_fb_blit_toio(dst, odev->pitch, odev->format->format, vmap, fb, &src_clip);
> > +
> > + drm_dev_exit(idx);
> > +}
> > +
> > +static void ofdrm_simple_display_pipe_disable(struct drm_simple_display_pipe *pipe)
> > +{
> > + struct ofdrm_device *odev = ofdrm_device_of_dev(pipe->crtc.dev);
> > + struct drm_device *dev = &odev->dev;
> > + int idx;
> > +
> > + if (!drm_dev_enter(dev, &idx))
> > + return;
> > +
> > + /* Clear screen to black if disabled */
> > + memset_io(odev->screen_base, 0, odev->pitch * odev->mode.vdisplay);
> > +
> > + drm_dev_exit(idx);
> > +}
> > +
> > +static void ofdrm_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
> > + struct drm_plane_state *old_plane_state)
> > +{
> > + struct ofdrm_device *odev = ofdrm_device_of_dev(pipe->crtc.dev);
> > + struct drm_plane_state *plane_state = pipe->plane.state;
> > + struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
> > + void *vmap = shadow_plane_state->data[0].vaddr; /* TODO: Use mapping abstraction */
> > + struct drm_framebuffer *fb = plane_state->fb;
> > + struct drm_device *dev = &odev->dev;
> > + struct drm_atomic_helper_damage_iter damage_iter;
> > + struct drm_rect src_clip, dst_clip;
> > + void __iomem *dst;
> > + int idx;
> > +
> > + if (!fb)
> > + return;
> > +
> > + if (!drm_dev_enter(dev, &idx))
> > + return;
> > +
> > + drm_atomic_helper_damage_iter_init(&damage_iter, old_plane_state, plane_state);
> > + drm_atomic_for_each_plane_damage(&damage_iter, &src_clip) {
> > +
> > + dst_clip = plane_state->dst;
> > + if (!drm_rect_intersect(&dst_clip, &src_clip))
> > + continue;
> > +
> > + dst = odev->screen_base;
> > + dst += drm_fb_clip_offset(odev->pitch, odev->format, &dst_clip);
> > + drm_fb_blit_toio(dst, odev->pitch, odev->format->format, vmap, fb, &src_clip);
> > + }
> > +
> > + drm_dev_exit(idx);
> > +}
> > +
> > +static const struct drm_simple_display_pipe_funcs ofdrm_simple_display_pipe_funcs = {
> > + .mode_valid = ofdrm_simple_display_pipe_mode_valid,
> > + .enable = ofdrm_simple_display_pipe_enable,
> > + .disable = ofdrm_simple_display_pipe_disable,
> > + .update = ofdrm_simple_display_pipe_update,
> > + DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
> > +};
> > +
> > +static const struct drm_mode_config_funcs ofdrm_mode_config_funcs = {
> > + .fb_create = drm_gem_fb_create_with_dirty,
> > + .atomic_check = drm_atomic_helper_check,
> > + .atomic_commit = drm_atomic_helper_commit,
> > +};
> > +
> > +static const uint32_t *ofdrm_device_formats(struct ofdrm_device *odev, size_t *nformats_out)
> > +{
> > + struct drm_device *dev = &odev->dev;
> > + size_t i;
> > +
> > + if (odev->nformats)
> > + goto out; /* don't rebuild list on recurring calls */
> > +
> > + /* native format goes first */
> > + odev->formats[0] = odev->format->format;
> > + odev->nformats = 1;
> > +
> > + /* default formats go second */
> > + for (i = 0; i < ARRAY_SIZE(ofdrm_default_formats); ++i) {
> > + if (ofdrm_default_formats[i] == odev->format->format)
> > + continue; /* native format already went first */
> > + odev->formats[odev->nformats] = ofdrm_default_formats[i];
> > + odev->nformats++;
> > + }
> > +
> > + /*
> > + * TODO: The ofdrm driver converts framebuffers to the native
> > + * format when copying them to device memory. If there are more
> > + * formats listed than supported by the driver, the native format
> > + * is not supported by the conversion helpers. Therefore *only*
> > + * support the native format and add a conversion helper ASAP.
> > + */
> > + if (drm_WARN_ONCE(dev, i != odev->nformats,
> > + "format conversion helpers required for %p4cc",
> > + &odev->format->format)) {
> > + odev->nformats = 1;
> > + }
> > +
> > +out:
> > + *nformats_out = odev->nformats;
> > + return odev->formats;
> > +}
> > +
> > +static int ofdrm_device_init_modeset(struct ofdrm_device *odev)
> > +{
> > + struct drm_device *dev = &odev->dev;
> > + struct drm_display_mode *mode = &odev->mode;
> > + struct drm_connector *connector = &odev->connector;
> > + struct drm_simple_display_pipe *pipe = &odev->pipe;
> > + unsigned long max_width, max_height;
> > + const uint32_t *formats;
> > + size_t nformats;
> > + int ret;
> > +
> > + ret = drmm_mode_config_init(dev);
> > + if (ret)
> > + return ret;
> > +
> > + max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
> > + max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
> > +
> > + dev->mode_config.min_width = mode->hdisplay;
> > + dev->mode_config.max_width = max_width;
> > + dev->mode_config.min_height = mode->vdisplay;
> > + dev->mode_config.max_height = max_height;
> > + dev->mode_config.preferred_depth = odev->format->cpp[0] * 8;
> > + dev->mode_config.funcs = &ofdrm_mode_config_funcs;
> > +
> > + ret = drm_connector_init(dev, connector, &ofdrm_connector_funcs,
> > + DRM_MODE_CONNECTOR_Unknown);
> > + if (ret)
> > + return ret;
> > + drm_connector_helper_add(connector, &ofdrm_connector_helper_funcs);
> > + drm_connector_set_panel_orientation_with_quirk(connector,
> > + DRM_MODE_PANEL_ORIENTATION_UNKNOWN,
> > + mode->hdisplay, mode->vdisplay);
> > +
> > + formats = ofdrm_device_formats(odev, &nformats);
> > +
> > + ret = drm_simple_display_pipe_init(dev, pipe, &ofdrm_simple_display_pipe_funcs,
> > + formats, nformats, ofdrm_format_modifiers,
> > + connector);
> > + if (ret)
> > + return ret;
> > +
> > + drm_plane_enable_fb_damage_clips(&pipe->plane);
> > +
> > + drm_mode_config_reset(dev);
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Init / Cleanup
> > + */
> > +
> > +static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
> > + struct platform_device *pdev)
> > +{
> > + struct ofdrm_device *odev;
> > + int ret;
> > +
> > + odev = devm_drm_dev_alloc(&pdev->dev, drv, struct ofdrm_device, dev);
> > + if (IS_ERR(odev))
> > + return ERR_CAST(odev);
> > + odev->pdev = pdev;
> > + platform_set_drvdata(pdev, &odev->dev);
> > +
> > + ret = ofdrm_device_init_fb(odev);
> > + if (ret)
> > + return ERR_PTR(ret);
> > + ret = ofdrm_device_init_mm(odev);
> > + if (ret)
> > + return ERR_PTR(ret);
> > + ret = ofdrm_device_init_modeset(odev);
> > + if (ret)
> > + return ERR_PTR(ret);
> > +
> > + return odev;
> > +}
> > +
> > +/*
> > + * DRM driver
> > + */
> > +
> > +DEFINE_DRM_GEM_FOPS(ofdrm_fops);
> > +
> > +static struct drm_driver ofdrm_driver = {
> > + DRM_GEM_SHMEM_DRIVER_OPS,
> > + .name = DRIVER_NAME,
> > + .desc = DRIVER_DESC,
> > + .date = DRIVER_DATE,
> > + .major = DRIVER_MAJOR,
> > + .minor = DRIVER_MINOR,
> > + .driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
> > + .fops = &ofdrm_fops,
> > +};
> > +
> > +/*
> > + * Platform driver
> > + */
> > +
> > +static int ofdrm_probe(struct platform_device *pdev)
> > +{
> > + struct ofdrm_device *odev;
> > + struct drm_device *dev;
> > + int ret;
> > +
> > + odev = ofdrm_device_create(&ofdrm_driver, pdev);
> > + if (IS_ERR(odev))
> > + return PTR_ERR(odev);
> > + dev = &odev->dev;
> > +
> > + ret = drm_dev_register(dev, 0);
> > + if (ret)
> > + return ret;
> > +
> > + drm_fbdev_generic_setup(dev, 0);
> > +
> > + return 0;
> > +}
> > +
> > +static int ofdrm_remove(struct platform_device *pdev)
> > +{
> > + struct drm_device *dev = platform_get_drvdata(pdev);
> > +
> > + drm_dev_unplug(dev);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id ofdrm_of_match_display[] = {
> > + { .compatible = "display", },
> > + { },
> > +};
> > +MODULE_DEVICE_TABLE(of, ofdrm_of_match_display);
> > +
> > +static struct platform_driver ofdrm_platform_driver = {
> > + .driver = {
> > + .name = "of-display",
> > + .of_match_table = ofdrm_of_match_display,
> > + },
> > + .probe = ofdrm_probe,
> > + .remove = ofdrm_remove,
> > +};
> > +
> > +module_platform_driver(ofdrm_platform_driver);
> > +
> > +MODULE_DESCRIPTION(DRIVER_DESC);
> > +MODULE_LICENSE("GPL");
> > diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
> > index e8a94e202d63..a4982dc3aa0d 100644
> > --- a/drivers/video/fbdev/Kconfig
> > +++ b/drivers/video/fbdev/Kconfig
> > @@ -455,6 +455,7 @@ config FB_ATARI
> > config FB_OF
> > bool "Open Firmware frame buffer device support"
> > depends on (FB = y) && PPC && (!PPC_PSERIES || PCI)
> > + depends on !DRM_OFDRM
> > select FB_CFB_FILLRECT
> > select FB_CFB_COPYAREA
> > select FB_CFB_IMAGEBLIT
>
>
> ATB,
>
> Mark.
