[PATCH v4 1/7] drm: Add DRM support for tiny LCD displays

Noralf Trønnes
2017-02-11T18:50:14Z

tinydrm provides helpers for very simple displays that can use
CMA backed framebuffers and need flushing on changes.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Thierry Reding <treding@nvidia.com>
---

Changes since version 3:
- Rebase on new drm_fbdev_cma_init_with_funcs() signature

Documentation/gpu/index.rst | 1 +
Documentation/gpu/tinydrm.rst | 21 ++
drivers/gpu/drm/Kconfig | 2 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/tinydrm/Kconfig | 8 +
drivers/gpu/drm/tinydrm/Makefile | 1 +
drivers/gpu/drm/tinydrm/core/Makefile | 3 +
drivers/gpu/drm/tinydrm/core/tinydrm-core.c | 376 ++++++++++++++++++++++++++++
drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c | 234 +++++++++++++++++
include/drm/tinydrm/tinydrm.h | 115 +++++++++
10 files changed, 762 insertions(+)
create mode 100644 Documentation/gpu/tinydrm.rst
create mode 100644 drivers/gpu/drm/tinydrm/Kconfig
create mode 100644 drivers/gpu/drm/tinydrm/Makefile
create mode 100644 drivers/gpu/drm/tinydrm/core/Makefile
create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-core.c
create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c
create mode 100644 include/drm/tinydrm/tinydrm.h

diff --git a/Documentation/gpu/index.rst b/Documentation/gpu/index.rst
index 367d7c3..f81278a 100644
--- a/Documentation/gpu/index.rst
+++ b/Documentation/gpu/index.rst
@@ -11,6 +11,7 @@ Linux GPU Driver Developer's Guide
drm-kms-helpers
drm-uapi
i915
+ tinydrm
vga-switcheroo
vgaarbiter

diff --git a/Documentation/gpu/tinydrm.rst b/Documentation/gpu/tinydrm.rst
new file mode 100644
index 0000000..ec4a20d
--- /dev/null
+++ b/Documentation/gpu/tinydrm.rst
@@ -0,0 +1,21 @@
+==========================
+drm/tinydrm Driver library
+==========================
+
+.. kernel-doc:: drivers/gpu/drm/tinydrm/core/tinydrm-core.c
+ :doc: overview
+
+Core functionality
+==================
+
+.. kernel-doc:: drivers/gpu/drm/tinydrm/core/tinydrm-core.c
+ :doc: core
+
+.. kernel-doc:: include/drm/tinydrm/tinydrm.h
+ :internal:
+
+.. kernel-doc:: drivers/gpu/drm/tinydrm/core/tinydrm-core.c
+ :export:
+
+.. kernel-doc:: drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c
+ :export:
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 90bc65d..88e01e08e 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -263,6 +263,8 @@ source "drivers/gpu/drm/mxsfb/Kconfig"

source "drivers/gpu/drm/meson/Kconfig"

+source "drivers/gpu/drm/tinydrm/Kconfig"
+
# Keep legacy drivers last

menuconfig DRM_LEGACY
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 92de399..3ee9579 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -94,3 +94,4 @@ obj-$(CONFIG_DRM_ARCPGU)+= arc/
obj-y += hisilicon/
obj-$(CONFIG_DRM_ZTE) += zte/
obj-$(CONFIG_DRM_MXSFB) += mxsfb/
+obj-$(CONFIG_DRM_TINYDRM) += tinydrm/
diff --git a/drivers/gpu/drm/tinydrm/Kconfig b/drivers/gpu/drm/tinydrm/Kconfig
new file mode 100644
index 0000000..ffb873f
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/Kconfig
@@ -0,0 +1,8 @@
+menuconfig DRM_TINYDRM
+ tristate "Support for simple displays"
+ depends on DRM
+ select DRM_KMS_HELPER
+ select DRM_KMS_CMA_HELPER
+ help
+ Choose this option if you have a tinydrm supported display.
+ If M is selected the module will be called tinydrm.
diff --git a/drivers/gpu/drm/tinydrm/Makefile b/drivers/gpu/drm/tinydrm/Makefile
new file mode 100644
index 0000000..7476ed1
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_DRM_TINYDRM) += core/
diff --git a/drivers/gpu/drm/tinydrm/core/Makefile b/drivers/gpu/drm/tinydrm/core/Makefile
new file mode 100644
index 0000000..4f14a0f
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/core/Makefile
@@ -0,0 +1,3 @@
+tinydrm-y := tinydrm-core.o tinydrm-pipe.o
+
+obj-$(CONFIG_DRM_TINYDRM) += tinydrm.o
diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-core.c b/drivers/gpu/drm/tinydrm/core/tinydrm-core.c
new file mode 100644
index 0000000..6a257dd
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/core/tinydrm-core.c
@@ -0,0 +1,376 @@
+/*
+ * Copyright (C) 2016 Noralf Trønnes
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/tinydrm/tinydrm.h>
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+
+/**
+ * DOC: overview
+ *
+ * This library provides driver helpers for very simple display hardware.
+ *
+ * It is based on &drm_simple_display_pipe coupled with a &drm_connector which
+ * has only one fixed &drm_display_mode. The framebuffers are backed by the
+ * cma helper and have support for framebuffer flushing (dirty).
+ * fbdev support is also included.
+ *
+ */
+
+/**
+ * DOC: core
+ *
+ * The driver allocates &tinydrm_device, initializes it using
+ * devm_tinydrm_init(), sets up the pipeline using tinydrm_display_pipe_init()
+ * and registers the DRM device using devm_tinydrm_register().
+ */
+
+/**
+ * tinydrm_lastclose - DRM lastclose helper
+ * @drm: DRM device
+ *
+ * This function ensures that fbdev is restored when drm_lastclose() is called
+ * on the last drm_release(). Drivers can use this as their
+ * &drm_driver->lastclose callback.
+ */
+void tinydrm_lastclose(struct drm_device *drm)
+{
+ struct tinydrm_device *tdev = drm->dev_private;
+
+ DRM_DEBUG_KMS("\n");
+ drm_fbdev_cma_restore_mode(tdev->fbdev_cma);
+}
+EXPORT_SYMBOL(tinydrm_lastclose);
+
+/**
+ * tinydrm_gem_cma_prime_import_sg_table - Produce a CMA GEM object from
+ * another driver's scatter/gather table of pinned pages
+ * @drm: DRM device to import into
+ * @attach: DMA-BUF attachment
+ * @sgt: Scatter/gather table of pinned pages
+ *
+ * This function imports a scatter/gather table exported via DMA-BUF by
+ * another driver using drm_gem_cma_prime_import_sg_table(). It sets the
+ * kernel virtual address on the CMA object. Drivers should use this as their
+ * &drm_driver->gem_prime_import_sg_table callback if they need the virtual
+ * address. tinydrm_gem_cma_free_object() should be used in combination with
+ * this function.
+ *
+ * Returns:
+ * A pointer to a newly created GEM object or an ERR_PTR-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_object *
+tinydrm_gem_cma_prime_import_sg_table(struct drm_device *drm,
+ struct dma_buf_attachment *attach,
+ struct sg_table *sgt)
+{
+ struct drm_gem_cma_object *cma_obj;
+ struct drm_gem_object *obj;
+ void *vaddr;
+
+ vaddr = dma_buf_vmap(attach->dmabuf);
+ if (!vaddr) {
+ DRM_ERROR("Failed to vmap PRIME buffer\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ obj = drm_gem_cma_prime_import_sg_table(drm, attach, sgt);
+ if (IS_ERR(obj)) {
+ dma_buf_vunmap(attach->dmabuf, vaddr);
+ return obj;
+ }
+
+ cma_obj = to_drm_gem_cma_obj(obj);
+ cma_obj->vaddr = vaddr;
+
+ return obj;
+}
+EXPORT_SYMBOL(tinydrm_gem_cma_prime_import_sg_table);
+
+/**
+ * tinydrm_gem_cma_free_object - Free resources associated with a CMA GEM
+ * object
+ * @gem_obj: GEM object to free
+ *
+ * This function frees the backing memory of the CMA GEM object, cleans up the
+ * GEM object state and frees the memory used to store the object itself using
+ * drm_gem_cma_free_object(). It also handles PRIME buffers which has the kernel
+ * virtual address set by tinydrm_gem_cma_prime_import_sg_table(). Drivers
+ * can use this as their &drm_driver->gem_free_object callback.
+ */
+void tinydrm_gem_cma_free_object(struct drm_gem_object *gem_obj)
+{
+ if (gem_obj->import_attach) {
+ struct drm_gem_cma_object *cma_obj;
+
+ cma_obj = to_drm_gem_cma_obj(gem_obj);
+ dma_buf_vunmap(gem_obj->import_attach->dmabuf, cma_obj->vaddr);
+ cma_obj->vaddr = NULL;
+ }
+
+ drm_gem_cma_free_object(gem_obj);
+}
+EXPORT_SYMBOL_GPL(tinydrm_gem_cma_free_object);
+
+const struct file_operations tinydrm_fops = {
+ .owner = THIS_MODULE,
+ .open = drm_open,
+ .release = drm_release,
+ .unlocked_ioctl = drm_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = drm_compat_ioctl,
+#endif
+ .poll = drm_poll,
+ .read = drm_read,
+ .llseek = no_llseek,
+ .mmap = drm_gem_cma_mmap,
+};
+EXPORT_SYMBOL(tinydrm_fops);
+
+static struct drm_framebuffer *
+tinydrm_fb_create(struct drm_device *drm, struct drm_file *file_priv,
+ const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+ struct tinydrm_device *tdev = drm->dev_private;
+
+ return drm_fb_cma_create_with_funcs(drm, file_priv, mode_cmd,
+ tdev->fb_funcs);
+}
+
+static const struct drm_mode_config_funcs tinydrm_mode_config_funcs = {
+ .fb_create = tinydrm_fb_create,
+ .atomic_check = drm_atomic_helper_check,
+ .atomic_commit = drm_atomic_helper_commit,
+};
+
+static int tinydrm_init(struct device *parent, struct tinydrm_device *tdev,
+ const struct drm_framebuffer_funcs *fb_funcs,
+ struct drm_driver *driver)
+{
+ struct drm_device *drm;
+
+ mutex_init(&tdev->dirty_lock);
+ tdev->fb_funcs = fb_funcs;
+
+ /*
+ * We don't embed drm_device, because that prevent us from using
+ * devm_kzalloc() to allocate tinydrm_device in the driver since
+ * drm_dev_unref() frees the structure. The devm_ functions provide
+ * for easy error handling.
+ */
+ drm = drm_dev_alloc(driver, parent);
+ if (IS_ERR(drm))
+ return PTR_ERR(drm);
+
+ tdev->drm = drm;
+ drm->dev_private = tdev;
+ drm_mode_config_init(drm);
+ drm->mode_config.funcs = &tinydrm_mode_config_funcs;
+
+ return 0;
+}
+
+static void tinydrm_fini(struct tinydrm_device *tdev)
+{
+ drm_mode_config_cleanup(tdev->drm);
+ mutex_destroy(&tdev->dirty_lock);
+ tdev->drm->dev_private = NULL;
+ drm_dev_unref(tdev->drm);
+}
+
+static void devm_tinydrm_release(void *data)
+{
+ tinydrm_fini(data);
+}
+
+/**
+ * devm_tinydrm_init - Initialize tinydrm device
+ * @parent: Parent device object
+ * @tdev: tinydrm device
+ * @fb_funcs: Framebuffer functions
+ * @driver: DRM driver
+ *
+ * This function initializes @tdev, the underlying DRM device and it's
+ * mode_config. Resources will be automatically freed on driver detach (devres)
+ * using drm_mode_config_cleanup() and drm_dev_unref().
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int devm_tinydrm_init(struct device *parent, struct tinydrm_device *tdev,
+ const struct drm_framebuffer_funcs *fb_funcs,
+ struct drm_driver *driver)
+{
+ int ret;
+
+ ret = tinydrm_init(parent, tdev, fb_funcs, driver);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action(parent, devm_tinydrm_release, tdev);
+ if (ret)
+ tinydrm_fini(tdev);
+
+ return ret;
+}
+EXPORT_SYMBOL(devm_tinydrm_init);
+
+static int tinydrm_register(struct tinydrm_device *tdev)
+{
+ struct drm_device *drm = tdev->drm;
+ int bpp = drm->mode_config.preferred_depth;
+ struct drm_fbdev_cma *fbdev;
+ int ret;
+
+ ret = drm_dev_register(tdev->drm, 0);
+ if (ret)
+ return ret;
+
+ fbdev = drm_fbdev_cma_init_with_funcs(drm, bpp ? bpp : 32,
+ drm->mode_config.num_connector,
+ tdev->fb_funcs);
+ if (IS_ERR(fbdev))
+ DRM_ERROR("Failed to initialize fbdev: %ld\n", PTR_ERR(fbdev));
+ else
+ tdev->fbdev_cma = fbdev;
+
+ return 0;
+}
+
+static void tinydrm_unregister(struct tinydrm_device *tdev)
+{
+ struct drm_fbdev_cma *fbdev_cma = tdev->fbdev_cma;
+
+ drm_crtc_force_disable_all(tdev->drm);
+ /* don't restore fbdev in lastclose, keep pipeline disabled */
+ tdev->fbdev_cma = NULL;
+ drm_dev_unregister(tdev->drm);
+ if (fbdev_cma)
+ drm_fbdev_cma_fini(fbdev_cma);
+}
+
+static void devm_tinydrm_register_release(void *data)
+{
+ tinydrm_unregister(data);
+}
+
+/**
+ * devm_tinydrm_register - Register tinydrm device
+ * @tdev: tinydrm device
+ *
+ * This function registers the underlying DRM device and fbdev.
+ * These resources will be automatically unregistered on driver detach (devres)
+ * and the display pipeline will be disabled.
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int devm_tinydrm_register(struct tinydrm_device *tdev)
+{
+ struct device *dev = tdev->drm->dev;
+ int ret;
+
+ ret = tinydrm_register(tdev);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action(dev, devm_tinydrm_register_release, tdev);
+ if (ret)
+ tinydrm_unregister(tdev);
+
+ return ret;
+}
+EXPORT_SYMBOL(devm_tinydrm_register);
+
+/**
+ * tinydrm_shutdown - Shutdown tinydrm
+ * @tdev: tinydrm device
+ *
+ * This function makes sure that the display pipeline is disabled.
+ * Used by drivers in their shutdown callback to turn off the display
+ * on machine shutdown and reboot.
+ */
+void tinydrm_shutdown(struct tinydrm_device *tdev)
+{
+ drm_crtc_force_disable_all(tdev->drm);
+}
+EXPORT_SYMBOL(tinydrm_shutdown);
+
+/**
+ * tinydrm_suspend - Suspend tinydrm
+ * @tdev: tinydrm device
+ *
+ * Used in driver PM operations to suspend tinydrm.
+ * Suspends fbdev and DRM.
+ * Resume with tinydrm_resume().
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int tinydrm_suspend(struct tinydrm_device *tdev)
+{
+ struct drm_atomic_state *state;
+
+ if (tdev->suspend_state) {
+ DRM_ERROR("Failed to suspend: state already set\n");
+ return -EINVAL;
+ }
+
+ drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 1);
+ state = drm_atomic_helper_suspend(tdev->drm);
+ if (IS_ERR(state)) {
+ drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 0);
+ return PTR_ERR(state);
+ }
+
+ tdev->suspend_state = state;
+
+ return 0;
+}
+EXPORT_SYMBOL(tinydrm_suspend);
+
+/**
+ * tinydrm_resume - Resume tinydrm
+ * @tdev: tinydrm device
+ *
+ * Used in driver PM operations to resume tinydrm.
+ * Suspend with tinydrm_suspend().
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int tinydrm_resume(struct tinydrm_device *tdev)
+{
+ struct drm_atomic_state *state = tdev->suspend_state;
+ int ret;
+
+ if (!state) {
+ DRM_ERROR("Failed to resume: state is not set\n");
+ return -EINVAL;
+ }
+
+ tdev->suspend_state = NULL;
+
+ ret = drm_atomic_helper_resume(tdev->drm, state);
+ if (ret) {
+ DRM_ERROR("Error resuming state: %d\n", ret);
+ return ret;
+ }
+
+ drm_fbdev_cma_set_suspend_unlocked(tdev->fbdev_cma, 0);
+
+ return 0;
+}
+EXPORT_SYMBOL(tinydrm_resume);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c b/drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c
new file mode 100644
index 0000000..ec43fb7
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c
@@ -0,0 +1,234 @@
+/*
+ * Copyright (C) 2016 Noralf Trønnes
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_modes.h>
+#include <drm/tinydrm/tinydrm.h>
+
+struct tinydrm_connector {
+ struct drm_connector base;
+ const struct drm_display_mode *mode;
+};
+
+static inline struct tinydrm_connector *
+to_tinydrm_connector(struct drm_connector *connector)
+{
+ return container_of(connector, struct tinydrm_connector, base);
+}
+
+static int tinydrm_connector_get_modes(struct drm_connector *connector)
+{
+ struct tinydrm_connector *tconn = to_tinydrm_connector(connector);
+ struct drm_display_mode *mode;
+
+ mode = drm_mode_duplicate(connector->dev, tconn->mode);
+ if (!mode) {
+ DRM_ERROR("Failed to duplicate mode\n");
+ 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;
+ connector->display_info.height_mm = mode->height_mm;
+ }
+
+ return 1;
+}
+
+static const struct drm_connector_helper_funcs tinydrm_connector_hfuncs = {
+ .get_modes = tinydrm_connector_get_modes,
+ .best_encoder = drm_atomic_helper_best_encoder,
+};
+
+static enum drm_connector_status
+tinydrm_connector_detect(struct drm_connector *connector, bool force)
+{
+ if (drm_device_is_unplugged(connector->dev))
+ return connector_status_disconnected;
+
+ return connector->status;
+}
+
+static void tinydrm_connector_destroy(struct drm_connector *connector)
+{
+ struct tinydrm_connector *tconn = to_tinydrm_connector(connector);
+
+ drm_connector_cleanup(connector);
+ kfree(tconn);
+}
+
+static const struct drm_connector_funcs tinydrm_connector_funcs = {
+ .dpms = drm_atomic_helper_connector_dpms,
+ .reset = drm_atomic_helper_connector_reset,
+ .detect = tinydrm_connector_detect,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = tinydrm_connector_destroy,
+ .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+struct drm_connector *
+tinydrm_connector_create(struct drm_device *drm,
+ const struct drm_display_mode *mode,
+ int connector_type)
+{
+ struct tinydrm_connector *tconn;
+ struct drm_connector *connector;
+ int ret;
+
+ tconn = kzalloc(sizeof(*tconn), GFP_KERNEL);
+ if (!tconn)
+ return ERR_PTR(-ENOMEM);
+
+ tconn->mode = mode;
+ connector = &tconn->base;
+
+ drm_connector_helper_add(connector, &tinydrm_connector_hfuncs);
+ ret = drm_connector_init(drm, connector, &tinydrm_connector_funcs,
+ connector_type);
+ if (ret) {
+ kfree(tconn);
+ return ERR_PTR(ret);
+ }
+
+ connector->status = connector_status_connected;
+
+ return connector;
+}
+
+/**
+ * tinydrm_display_pipe_update - Display pipe update helper
+ * @pipe: Simple display pipe
+ * @old_state: Old plane state
+ *
+ * This function does a full framebuffer flush if the plane framebuffer
+ * has changed. It also handles vblank events. Drivers can use this as their
+ * &drm_simple_display_pipe_funcs->update callback.
+ */
+void tinydrm_display_pipe_update(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *old_state)
+{
+ struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+ struct drm_framebuffer *fb = pipe->plane.state->fb;
+ struct drm_crtc *crtc = &tdev->pipe.crtc;
+
+ if (fb && (fb != old_state->fb)) {
+ pipe->plane.fb = fb;
+ if (fb->funcs->dirty)
+ fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
+ }
+
+ if (crtc->state->event) {
+ spin_lock_irq(&crtc->dev->event_lock);
+ drm_crtc_send_vblank_event(crtc, crtc->state->event);
+ spin_unlock_irq(&crtc->dev->event_lock);
+ crtc->state->event = NULL;
+ }
+}
+EXPORT_SYMBOL(tinydrm_display_pipe_update);
+
+/**
+ * tinydrm_display_pipe_prepare_fb - Display pipe prepare_fb helper
+ * @pipe: Simple display pipe
+ * @plane_state: Plane state
+ *
+ * This function uses drm_fb_cma_prepare_fb() to check if the plane FB has an
+ * dma-buf attached, extracts the exclusive fence and attaches it to plane
+ * state for the atomic helper to wait on. Drivers can use this as their
+ * &drm_simple_display_pipe_funcs->prepare_fb callback.
+ */
+int tinydrm_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *plane_state)
+{
+ return drm_fb_cma_prepare_fb(&pipe->plane, plane_state);
+}
+EXPORT_SYMBOL(tinydrm_display_pipe_prepare_fb);
+
+static int tinydrm_rotate_mode(struct drm_display_mode *mode,
+ unsigned int rotation)
+{
+ if (rotation == 0 || rotation == 180) {
+ return 0;
+ } else if (rotation == 90 || rotation == 270) {
+ swap(mode->hdisplay, mode->vdisplay);
+ swap(mode->hsync_start, mode->vsync_start);
+ swap(mode->hsync_end, mode->vsync_end);
+ swap(mode->htotal, mode->vtotal);
+ swap(mode->width_mm, mode->height_mm);
+ return 0;
+ } else {
+ return -EINVAL;
+ }
+}
+
+/**
+ * tinydrm_display_pipe_init - Initialize display pipe
+ * @tdev: tinydrm device
+ * @funcs: Display pipe functions
+ * @connector_type: Connector type
+ * @formats: Array of supported formats (DRM_FORMAT\_\*)
+ * @format_count: Number of elements in @formats
+ * @mode: Supported mode
+ * @rotation: Initial @mode rotation in degrees Counter Clock Wise
+ *
+ * This function sets up a &drm_simple_display_pipe with a &drm_connector that
+ * has one fixed &drm_display_mode which is rotated according to @rotation.
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int
+tinydrm_display_pipe_init(struct tinydrm_device *tdev,
+ const struct drm_simple_display_pipe_funcs *funcs,
+ int connector_type,
+ const uint32_t *formats,
+ unsigned int format_count,
+ const struct drm_display_mode *mode,
+ unsigned int rotation)
+{
+ struct drm_device *drm = tdev->drm;
+ struct drm_display_mode *mode_copy;
+ struct drm_connector *connector;
+ int ret;
+
+ mode_copy = devm_kmalloc(drm->dev, sizeof(*mode_copy), GFP_KERNEL);
+ if (!mode_copy)
+ return -ENOMEM;
+
+ *mode_copy = *mode;
+ ret = tinydrm_rotate_mode(mode_copy, rotation);
+ if (ret) {
+ DRM_ERROR("Illegal rotation value %u\n", rotation);
+ return -EINVAL;
+ }
+
+ drm->mode_config.min_width = mode_copy->hdisplay;
+ drm->mode_config.max_width = mode_copy->hdisplay;
+ drm->mode_config.min_height = mode_copy->vdisplay;
+ drm->mode_config.max_height = mode_copy->vdisplay;
+
+ connector = tinydrm_connector_create(drm, mode_copy, connector_type);
+ if (IS_ERR(connector))
+ return PTR_ERR(connector);
+
+ ret = drm_simple_display_pipe_init(drm, &tdev->pipe, funcs, formats,
+ format_count, connector);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+EXPORT_SYMBOL(tinydrm_display_pipe_init);
diff --git a/include/drm/tinydrm/tinydrm.h b/include/drm/tinydrm/tinydrm.h
new file mode 100644
index 0000000..cf9ca20
--- /dev/null
+++ b/include/drm/tinydrm/tinydrm.h
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2016 Noralf Trønnes
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_TINYDRM_H
+#define __LINUX_TINYDRM_H
+
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_simple_kms_helper.h>
+
+/**
+ * struct tinydrm_device - tinydrm device
+ * @drm: DRM device
+ * @pipe: Display pipe structure
+ * @dirty_lock: Serializes framebuffer flushing
+ * @fbdev_cma: CMA fbdev structure
+ * @suspend_state: Atomic state when suspended
+ * @fb_funcs: Framebuffer functions used when creating framebuffers
+ */
+struct tinydrm_device {
+ struct drm_device *drm;
+ struct drm_simple_display_pipe pipe;
+ struct mutex dirty_lock;
+ struct drm_fbdev_cma *fbdev_cma;
+ struct drm_atomic_state *suspend_state;
+ const struct drm_framebuffer_funcs *fb_funcs;
+};
+
+static inline struct tinydrm_device *
+pipe_to_tinydrm(struct drm_simple_display_pipe *pipe)
+{
+ return container_of(pipe, struct tinydrm_device, pipe);
+}
+
+/**
+ * TINYDRM_GEM_DRIVER_OPS - default tinydrm gem operations
+ *
+ * This macro provides a shortcut for setting the tinydrm GEM operations in
+ * the &drm_driver structure.
+ */
+#define TINYDRM_GEM_DRIVER_OPS \
+ .gem_free_object = tinydrm_gem_cma_free_object, \
+ .gem_vm_ops = &drm_gem_cma_vm_ops, \
+ .prime_handle_to_fd = drm_gem_prime_handle_to_fd, \
+ .prime_fd_to_handle = drm_gem_prime_fd_to_handle, \
+ .gem_prime_import = drm_gem_prime_import, \
+ .gem_prime_export = drm_gem_prime_export, \
+ .gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table, \
+ .gem_prime_import_sg_table = tinydrm_gem_cma_prime_import_sg_table, \
+ .gem_prime_vmap = drm_gem_cma_prime_vmap, \
+ .gem_prime_vunmap = drm_gem_cma_prime_vunmap, \
+ .gem_prime_mmap = drm_gem_cma_prime_mmap, \
+ .dumb_create = drm_gem_cma_dumb_create, \
+ .dumb_map_offset = drm_gem_cma_dumb_map_offset, \
+ .dumb_destroy = drm_gem_dumb_destroy, \
+ .fops = &tinydrm_fops
+
+/**
+ * TINYDRM_MODE - tinydrm display mode
+ * @hd: Horizontal resolution, width
+ * @vd: Vertical resolution, height
+ * @hd_mm: Display width in millimeters
+ * @vd_mm: Display height in millimeters
+ *
+ * This macro creates a &drm_display_mode for use with tinydrm.
+ */
+#define TINYDRM_MODE(hd, vd, hd_mm, vd_mm) \
+ .hdisplay = (hd), \
+ .hsync_start = (hd), \
+ .hsync_end = (hd), \
+ .htotal = (hd), \
+ .vdisplay = (vd), \
+ .vsync_start = (vd), \
+ .vsync_end = (vd), \
+ .vtotal = (vd), \
+ .width_mm = (hd_mm), \
+ .height_mm = (vd_mm), \
+ .type = DRM_MODE_TYPE_DRIVER, \
+ .clock = 1 /* pass validation */
+
+extern const struct file_operations tinydrm_fops;
+void tinydrm_lastclose(struct drm_device *drm);
+void tinydrm_gem_cma_free_object(struct drm_gem_object *gem_obj);
+struct drm_gem_object *
+tinydrm_gem_cma_prime_import_sg_table(struct drm_device *drm,
+ struct dma_buf_attachment *attach,
+ struct sg_table *sgt);
+int devm_tinydrm_init(struct device *parent, struct tinydrm_device *tdev,
+ const struct drm_framebuffer_funcs *fb_funcs,
+ struct drm_driver *driver);
+int devm_tinydrm_register(struct tinydrm_device *tdev);
+void tinydrm_shutdown(struct tinydrm_device *tdev);
+int tinydrm_suspend(struct tinydrm_device *tdev);
+int tinydrm_resume(struct tinydrm_device *tdev);
+
+void tinydrm_display_pipe_update(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *old_state);
+int tinydrm_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *plane_state);
+int
+tinydrm_display_pipe_init(struct tinydrm_device *tdev,
+ const struct drm_simple_display_pipe_funcs *funcs,
+ int connector_type,
+ const uint32_t *formats,
+ unsigned int format_count,
+ const struct drm_display_mode *mode,
+ unsigned int rotation);
+
+#endif /* __LINUX_TINYDRM_H */
--
2.10.2