Merge tag 'drm-tinydrm-2017-02-18' of https://github.com/notro/linux into drm-next

Add tinydrm

* tag 'drm-tinydrm-2017-02-18' of https://github.com/notro/linux:
  drm/tinydrm: Add support for Multi-Inno MI0283QT display
  dt-bindings: Add Multi-Inno MI0283QT binding
  dt-bindings: display/panel: Add common rotation property
  of: Add vendor prefix for Multi-Inno
  drm/tinydrm: Add MIPI DBI support
  drm/tinydrm: Add helper functions
  drm: Add DRM support for tiny LCD displays

Documentation/devicetree/bindings/display/multi-inno,mi0283qt.txt

+Multi-Inno MI0283QT display panel
+
+Required properties:
+- compatible:	"multi-inno,mi0283qt".
+
+The node for this driver must be a child node of a SPI controller, hence
+all mandatory properties described in ../spi/spi-bus.txt must be specified.
+
+Optional properties:
+- dc-gpios:	D/C pin. The presence/absence of this GPIO determines
+		the panel interface mode (IM[3:0] pins):
+		- present: IM=x110 4-wire 8-bit data serial interface
+		- absent:  IM=x101 3-wire 9-bit data serial interface
+- reset-gpios:	Reset pin
+- power-supply:	A regulator node for the supply voltage.
+- backlight:	phandle of the backlight device attached to the panel
+- rotation:	panel rotation in degrees counter clockwise (0,90,180,270)
+
+Example:
+	mi0283qt@0{
+		compatible = "multi-inno,mi0283qt";
+		reg = <0>;
+		spi-max-frequency = <32000000>;
+		rotation = <90>;
+		dc-gpios = <&gpio 25 0>;
+		backlight = <&backlight>;
+	};

Documentation/devicetree/bindings/display/panel/panel.txt

+Common display properties
+-------------------------
+
+- rotation:	Display rotation in degrees counter clockwise (0,90,180,270)

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -187,6 +187,7 @@ mpl	MPL AG
 mqmaker	mqmaker Inc.
 msi	Micro-Star International Co. Ltd.
 mti	Imagination Technologies Ltd. (formerly MIPS Technologies Inc.)
+multi-inno	Multi-Inno Technology Co.,Ltd
 mundoreader	Mundo Reader S.L.
 murata	Murata Manufacturing Co., Ltd.
 mxicy	Macronix International Co., Ltd.

Documentation/gpu/index.rst

@@ -11,6 +11,7 @@ Linux GPU Driver Developer's Guide
    drm-kms-helpers
    drm-uapi
    i915
+   tinydrm
    vga-switcheroo
    vgaarbiter
 

Documentation/gpu/tinydrm.rst

+==========================
+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:
+
+Additional helpers
+==================
+
+.. kernel-doc:: include/drm/tinydrm/tinydrm-helpers.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c
+   :export:
+
+MIPI DBI Compatible Controllers
+===============================
+
+.. kernel-doc:: drivers/gpu/drm/tinydrm/mipi-dbi.c
+   :doc: overview
+
+.. kernel-doc:: include/drm/tinydrm/mipi-dbi.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/tinydrm/mipi-dbi.c
+   :export:

MAINTAINERS

@@ -4245,6 +4245,12 @@ S:	Supported
 F:	drivers/gpu/drm/mediatek/
 F:	Documentation/devicetree/bindings/display/mediatek/
 
+DRM DRIVER FOR MI0283QT
+M:	Noralf Trønnes <noralf@tronnes.org>
+S:	Maintained
+F:	drivers/gpu/drm/tinydrm/mi0283qt.c
+F:	Documentation/devicetree/bindings/display/multi-inno,mi0283qt.txt
+
 DRM DRIVER FOR MSM ADRENO GPU
 M:	Rob Clark <robdclark@gmail.com>
 L:	linux-arm-msm@vger.kernel.org

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

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/

drivers/gpu/drm/tinydrm/Kconfig

+menuconfig DRM_TINYDRM
+	tristate "Support for simple displays"
+	depends on DRM
+	select DRM_KMS_HELPER
+	select DRM_KMS_CMA_HELPER
+	select BACKLIGHT_LCD_SUPPORT
+	select BACKLIGHT_CLASS_DEVICE
+	help
+	  Choose this option if you have a tinydrm supported display.
+	  If M is selected the module will be called tinydrm.
+
+config TINYDRM_MIPI_DBI
+	tristate
+
+config TINYDRM_MI0283QT
+	tristate "DRM support for MI0283QT"
+	depends on DRM_TINYDRM && SPI
+	select TINYDRM_MIPI_DBI
+	help
+	  DRM driver for the Multi-Inno MI0283QT display panel
+	  If M is selected the module will be called mi0283qt.

drivers/gpu/drm/tinydrm/Makefile

+obj-$(CONFIG_DRM_TINYDRM)		+= core/
+
+# Controllers
+obj-$(CONFIG_TINYDRM_MIPI_DBI)		+= mipi-dbi.o
+
+# Displays
+obj-$(CONFIG_TINYDRM_MI0283QT)		+= mi0283qt.o

drivers/gpu/drm/tinydrm/core/Makefile

+tinydrm-y := tinydrm-core.o tinydrm-pipe.o tinydrm-helpers.o
+
+obj-$(CONFIG_DRM_TINYDRM) += tinydrm.o

drivers/gpu/drm/tinydrm/core/tinydrm-core.c

+/*
+ * 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");

drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c

+/*
+ * 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/tinydrm/tinydrm.h>
+#include <drm/tinydrm/tinydrm-helpers.h>
+#include <linux/backlight.h>
+#include <linux/pm.h>
+#include <linux/spi/spi.h>
+#include <linux/swab.h>
+
+static unsigned int spi_max;
+module_param(spi_max, uint, 0400);
+MODULE_PARM_DESC(spi_max, "Set a lower SPI max transfer size");
+
+/**
+ * tinydrm_merge_clips - Merge clip rectangles
+ * @dst: Destination clip rectangle
+ * @src: Source clip rectangle(s)
+ * @num_clips: Number of @src clip rectangles
+ * @flags: Dirty fb ioctl flags
+ * @max_width: Maximum width of @dst
+ * @max_height: Maximum height of @dst
+ *
+ * This function merges @src clip rectangle(s) into @dst. If @src is NULL,
+ * @max_width and @min_width is used to set a full @dst clip rectangle.
+ *
+ * Returns:
+ * true if it's a full clip, false otherwise
+ */
+bool tinydrm_merge_clips(struct drm_clip_rect *dst,
+			 struct drm_clip_rect *src, unsigned int num_clips,
+			 unsigned int flags, u32 max_width, u32 max_height)
+{
+	unsigned int i;
+
+	if (!src || !num_clips) {
+		dst->x1 = 0;
+		dst->x2 = max_width;
+		dst->y1 = 0;
+		dst->y2 = max_height;
+		return true;
+	}
+
+	dst->x1 = ~0;
+	dst->y1 = ~0;
+	dst->x2 = 0;
+	dst->y2 = 0;
+
+	for (i = 0; i < num_clips; i++) {
+		if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY)
+			i++;
+		dst->x1 = min(dst->x1, src[i].x1);
+		dst->x2 = max(dst->x2, src[i].x2);
+		dst->y1 = min(dst->y1, src[i].y1);
+		dst->y2 = max(dst->y2, src[i].y2);
+	}
+
+	if (dst->x2 > max_width || dst->y2 > max_height ||
+	    dst->x1 >= dst->x2 || dst->y1 >= dst->y2) {
+		DRM_DEBUG_KMS("Illegal clip: x1=%u, x2=%u, y1=%u, y2=%u\n",
+			      dst->x1, dst->x2, dst->y1, dst->y2);
+		dst->x1 = 0;
+		dst->y1 = 0;
+		dst->x2 = max_width;
+		dst->y2 = max_height;
+	}
+
+	return (dst->x2 - dst->x1) == max_width &&
+	       (dst->y2 - dst->y1) == max_height;
+}
+EXPORT_SYMBOL(tinydrm_merge_clips);
+
+/**
+ * tinydrm_memcpy - Copy clip buffer
+ * @dst: Destination buffer
+ * @vaddr: Source buffer
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ */
+void tinydrm_memcpy(void *dst, void *vaddr, struct drm_framebuffer *fb,
+		    struct drm_clip_rect *clip)
+{
+	unsigned int cpp = drm_format_plane_cpp(fb->format->format, 0);
+	unsigned int pitch = fb->pitches[0];
+	void *src = vaddr + (clip->y1 * pitch) + (clip->x1 * cpp);
+	size_t len = (clip->x2 - clip->x1) * cpp;
+	unsigned int y;
+
+	for (y = clip->y1; y < clip->y2; y++) {
+		memcpy(dst, src, len);
+		src += pitch;
+		dst += len;
+	}
+}
+EXPORT_SYMBOL(tinydrm_memcpy);
+
+/**
+ * tinydrm_swab16 - Swap bytes into clip buffer
+ * @dst: RGB565 destination buffer
+ * @vaddr: RGB565 source buffer
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ */
+void tinydrm_swab16(u16 *dst, void *vaddr, struct drm_framebuffer *fb,
+		    struct drm_clip_rect *clip)
+{
+	size_t len = (clip->x2 - clip->x1) * sizeof(u16);
+	unsigned int x, y;
+	u16 *src, *buf;
+
+	/*
+	 * The cma memory is write-combined so reads are uncached.
+	 * Speed up by fetching one line at a time.
+	 */
+	buf = kmalloc(len, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	for (y = clip->y1; y < clip->y2; y++) {
+		src = vaddr + (y * fb->pitches[0]);
+		src += clip->x1;
+		memcpy(buf, src, len);
+		src = buf;
+		for (x = clip->x1; x < clip->x2; x++)
+			*dst++ = swab16(*src++);
+	}
+
+	kfree(buf);
+}
+EXPORT_SYMBOL(tinydrm_swab16);
+
+/**
+ * tinydrm_xrgb8888_to_rgb565 - Convert XRGB8888 to RGB565 clip buffer
+ * @dst: RGB565 destination buffer
+ * @vaddr: XRGB8888 source buffer
+ * @fb: DRM framebuffer
+ * @clip: Clip rectangle area to copy
+ * @swap: Swap bytes
+ *
+ * Drivers can use this function for RGB565 devices that don't natively
+ * support XRGB8888.
+ */
+void tinydrm_xrgb8888_to_rgb565(u16 *dst, void *vaddr,
+				struct drm_framebuffer *fb,
+				struct drm_clip_rect *clip, bool swap)
+{
+	size_t len = (clip->x2 - clip->x1) * sizeof(u32);
+	unsigned int x, y;
+	u32 *src, *buf;
+	u16 val16;
+
+	buf = kmalloc(len, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	for (y = clip->y1; y < clip->y2; y++) {
+		src = vaddr + (y * fb->pitches[0]);
+		src += clip->x1;
+		memcpy(buf, src, len);
+		src = buf;
+		for (x = clip->x1; x < clip->x2; x++) {
+			val16 = ((*src & 0x00F80000) >> 8) |
+				((*src & 0x0000FC00) >> 5) |
+				((*src & 0x000000F8) >> 3);
+			src++;
+			if (swap)
+				*dst++ = swab16(val16);
+			else
+				*dst++ = val16;
+		}
+	}
+
+	kfree(buf);
+}
+EXPORT_SYMBOL(tinydrm_xrgb8888_to_rgb565);
+
+/**
+ * tinydrm_of_find_backlight - Find backlight device in device-tree
+ * @dev: Device
+ *
+ * This function looks for a DT node pointed to by a property named 'backlight'
+ * and uses of_find_backlight_by_node() to get the backlight device.
+ * Additionally if the brightness property is zero, it is set to
+ * max_brightness.
+ *
+ * Returns:
+ * NULL if there's no backlight property.
+ * Error pointer -EPROBE_DEFER if the DT node is found, but no backlight device
+ * is found.
+ * If the backlight device is found, a pointer to the structure is returned.
+ */
+struct backlight_device *tinydrm_of_find_backlight(struct device *dev)
+{
+	struct backlight_device *backlight;
+	struct device_node *np;
+
+	np = of_parse_phandle(dev->of_node, "backlight", 0);
+	if (!np)
+		return NULL;
+
+	backlight = of_find_backlight_by_node(np);
+	of_node_put(np);
+
+	if (!backlight)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	if (!backlight->props.brightness) {
+		backlight->props.brightness = backlight->props.max_brightness;
+		DRM_DEBUG_KMS("Backlight brightness set to %d\n",
+			      backlight->props.brightness);
+	}
+
+	return backlight;
+}
+EXPORT_SYMBOL(tinydrm_of_find_backlight);
+
+/**
+ * tinydrm_enable_backlight - Enable backlight helper
+ * @backlight: Backlight device
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int tinydrm_enable_backlight(struct backlight_device *backlight)
+{
+	unsigned int old_state;
+	int ret;
+
+	if (!backlight)
+		return 0;
+
+	old_state = backlight->props.state;
+	backlight->props.state &= ~BL_CORE_FBBLANK;
+	DRM_DEBUG_KMS("Backlight state: 0x%x -> 0x%x\n", old_state,
+		      backlight->props.state);
+
+	ret = backlight_update_status(backlight);
+	if (ret)
+		DRM_ERROR("Failed to enable backlight %d\n", ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(tinydrm_enable_backlight);
+
+/**
+ * tinydrm_disable_backlight - Disable backlight helper
+ * @backlight: Backlight device
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int tinydrm_disable_backlight(struct backlight_device *backlight)
+{
+	unsigned int old_state;
+	int ret;
+
+	if (!backlight)
+		return 0;
+
+	old_state = backlight->props.state;
+	backlight->props.state |= BL_CORE_FBBLANK;
+	DRM_DEBUG_KMS("Backlight state: 0x%x -> 0x%x\n", old_state,
+		      backlight->props.state);
+	ret = backlight_update_status(backlight);
+	if (ret)
+		DRM_ERROR("Failed to disable backlight %d\n", ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(tinydrm_disable_backlight);
+
+#if IS_ENABLED(CONFIG_SPI)
+
+/**
+ * tinydrm_spi_max_transfer_size - Determine max SPI transfer size
+ * @spi: SPI device
+ * @max_len: Maximum buffer size needed (optional)
+ *
+ * This function returns the maximum size to use for SPI transfers. It checks
+ * the SPI master, the optional @max_len and the module parameter spi_max and
+ * returns the smallest.
+ *
+ * Returns:
+ * Maximum size for SPI transfers
+ */
+size_t tinydrm_spi_max_transfer_size(struct spi_device *spi, size_t max_len)
+{
+	size_t ret;
+
+	ret = min(spi_max_transfer_size(spi), spi->master->max_dma_len);
+	if (max_len)
+		ret = min(ret, max_len);
+	if (spi_max)
+		ret = min_t(size_t, ret, spi_max);
+	ret &= ~0x3;
+	if (ret < 4)
+		ret = 4;
+
+	return ret;
+}
+EXPORT_SYMBOL(tinydrm_spi_max_transfer_size);
+
+/**
+ * tinydrm_spi_bpw_supported - Check if bits per word is supported
+ * @spi: SPI device
+ * @bpw: Bits per word
+ *
+ * This function checks to see if the SPI master driver supports @bpw.
+ *
+ * Returns:
+ * True if @bpw is supported, false otherwise.
+ */
+bool tinydrm_spi_bpw_supported(struct spi_device *spi, u8 bpw)
+{
+	u32 bpw_mask = spi->master->bits_per_word_mask;
+
+	if (bpw == 8)
+		return true;
+
+	if (!bpw_mask) {
+		dev_warn_once(&spi->dev,
+			      "bits_per_word_mask not set, assume 8-bit only\n");
+		return false;
+	}
+
+	if (bpw_mask & SPI_BPW_MASK(bpw))
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL(tinydrm_spi_bpw_supported);
+
+static void
+tinydrm_dbg_spi_print(struct spi_device *spi, struct spi_transfer *tr,
+		      const void *buf, int idx, bool tx)
+{
+	u32 speed_hz = tr->speed_hz ? tr->speed_hz : spi->max_speed_hz;
+	char linebuf[3 * 32];
+
+	hex_dump_to_buffer(buf, tr->len, 16,
+			   DIV_ROUND_UP(tr->bits_per_word, 8),
+			   linebuf, sizeof(linebuf), false);
+
+	printk(KERN_DEBUG
+	       "    tr(%i): speed=%u%s, bpw=%i, len=%u, %s_buf=[%s%s]\n", idx,
+	       speed_hz > 1000000 ? speed_hz / 1000000 : speed_hz / 1000,
+	       speed_hz > 1000000 ? "MHz" : "kHz", tr->bits_per_word, tr->len,
+	       tx ? "tx" : "rx", linebuf, tr->len > 16 ? " ..." : "");
+}
+
+/* called through tinydrm_dbg_spi_message() */
+void _tinydrm_dbg_spi_message(struct spi_device *spi, struct spi_message *m)
+{
+	struct spi_transfer *tmp;
+	struct list_head *pos;
+	int i = 0;
+
+	list_for_each(pos, &m->transfers) {
+		tmp = list_entry(pos, struct spi_transfer, transfer_list);
+
+		if (tmp->tx_buf)
+			tinydrm_dbg_spi_print(spi, tmp, tmp->tx_buf, i, true);
+		if (tmp->rx_buf)
+			tinydrm_dbg_spi_print(spi, tmp, tmp->rx_buf, i, false);
+		i++;
+	}
+}
+EXPORT_SYMBOL(_tinydrm_dbg_spi_message);
+
+/**
+ * tinydrm_spi_transfer - SPI transfer helper
+ * @spi: SPI device
+ * @speed_hz: Override speed (optional)
+ * @header: Optional header transfer
+ * @bpw: Bits per word
+ * @buf: Buffer to transfer
+ * @len: Buffer length
+ *
+ * This SPI transfer helper breaks up the transfer of @buf into chunks which
+ * the SPI master driver can handle. If the machine is Little Endian and the
+ * SPI master driver doesn't support 16 bits per word, it swaps the bytes and
+ * does a 8-bit transfer.
+ * If @header is set, it is prepended to each SPI message.
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int tinydrm_spi_transfer(struct spi_device *spi, u32 speed_hz,
+			 struct spi_transfer *header, u8 bpw, const void *buf,
+			 size_t len)
+{
+	struct spi_transfer tr = {
+		.bits_per_word = bpw,
+		.speed_hz = speed_hz,
+	};
+	struct spi_message m;
+	u16 *swap_buf = NULL;
+	size_t max_chunk;
+	size_t chunk;
+	int ret = 0;
+
+	if (WARN_ON_ONCE(bpw != 8 && bpw != 16))
+		return -EINVAL;
+
+	max_chunk = tinydrm_spi_max_transfer_size(spi, 0);
+
+	if (drm_debug & DRM_UT_DRIVER)
+		pr_debug("[drm:%s] bpw=%u, max_chunk=%zu, transfers:\n",
+			 __func__, bpw, max_chunk);
+
+	if (bpw == 16 && !tinydrm_spi_bpw_supported(spi, 16)) {
+		tr.bits_per_word = 8;
+		if (tinydrm_machine_little_endian()) {
+			swap_buf = kmalloc(min(len, max_chunk), GFP_KERNEL);
+			if (!swap_buf)
+				return -ENOMEM;
+		}
+	}
+
+	spi_message_init(&m);
+	if (header)
+		spi_message_add_tail(header, &m);
+	spi_message_add_tail(&tr, &m);
+
+	while (len) {
+		chunk = min(len, max_chunk);
+
+		tr.tx_buf = buf;
+		tr.len = chunk;
+
+		if (swap_buf) {
+			const u16 *buf16 = buf;
+			unsigned int i;
+
+			for (i = 0; i < chunk / 2; i++)
+				swap_buf[i] = swab16(buf16[i]);
+
+			tr.tx_buf = swap_buf;
+		}
+
+		buf += chunk;
+		len -= chunk;
+
+		tinydrm_dbg_spi_message(spi, &m);
+		ret = spi_sync(spi, &m);
+		if (ret)
+			return ret;
+	};
+
+	return 0;
+}
+EXPORT_SYMBOL(tinydrm_spi_transfer);
+
+#endif /* CONFIG_SPI */

drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c

+/*
+ * 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);

drivers/gpu/drm/tinydrm/mi0283qt.c

+/*
+ * DRM driver for Multi-Inno MI0283QT panels
+ *
+ * Copyright 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/tinydrm/ili9341.h>
+#include <drm/tinydrm/mipi-dbi.h>
+#include <drm/tinydrm/tinydrm-helpers.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <video/mipi_display.h>
+
+static int mi0283qt_init(struct mipi_dbi *mipi)
+{
+	struct tinydrm_device *tdev = &mipi->tinydrm;
+	struct device *dev = tdev->drm->dev;
+	u8 addr_mode;
+	int ret;
+
+	DRM_DEBUG_KMS("\n");
+
+	ret = regulator_enable(mipi->regulator);
+	if (ret) {
+		dev_err(dev, "Failed to enable regulator %d\n", ret);
+		return ret;
+	}
+
+	/* Avoid flicker by skipping setup if the bootloader has done it */
+	if (mipi_dbi_display_is_on(mipi))
+		return 0;
+
+	mipi_dbi_hw_reset(mipi);
+	ret = mipi_dbi_command(mipi, MIPI_DCS_SOFT_RESET);
+	if (ret) {
+		dev_err(dev, "Error sending command %d\n", ret);
+		regulator_disable(mipi->regulator);
+		return ret;
+	}
+
+	msleep(20);
+
+	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
+
+	mipi_dbi_command(mipi, ILI9341_PWCTRLB, 0x00, 0x83, 0x30);
+	mipi_dbi_command(mipi, ILI9341_PWRSEQ, 0x64, 0x03, 0x12, 0x81);
+	mipi_dbi_command(mipi, ILI9341_DTCTRLA, 0x85, 0x01, 0x79);
+	mipi_dbi_command(mipi, ILI9341_PWCTRLA, 0x39, 0x2c, 0x00, 0x34, 0x02);
+	mipi_dbi_command(mipi, ILI9341_PUMPCTRL, 0x20);
+	mipi_dbi_command(mipi, ILI9341_DTCTRLB, 0x00, 0x00);
+
+	/* Power Control */
+	mipi_dbi_command(mipi, ILI9341_PWCTRL1, 0x26);
+	mipi_dbi_command(mipi, ILI9341_PWCTRL2, 0x11);
+	/* VCOM */
+	mipi_dbi_command(mipi, ILI9341_VMCTRL1, 0x35, 0x3e);
+	mipi_dbi_command(mipi, ILI9341_VMCTRL2, 0xbe);
+
+	/* Memory Access Control */
+	mipi_dbi_command(mipi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
+
+	switch (mipi->rotation) {
+	default:
+		addr_mode = ILI9341_MADCTL_MV | ILI9341_MADCTL_MY |
+			    ILI9341_MADCTL_MX;
+		break;
+	case 90:
+		addr_mode = ILI9341_MADCTL_MY;
+		break;
+	case 180:
+		addr_mode = ILI9341_MADCTL_MV;
+		break;
+	case 270:
+		addr_mode = ILI9341_MADCTL_MX;
+		break;
+	}
+	addr_mode |= ILI9341_MADCTL_BGR;
+	mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+
+	/* Frame Rate */
+	mipi_dbi_command(mipi, ILI9341_FRMCTR1, 0x00, 0x1b);
+
+	/* Gamma */
+	mipi_dbi_command(mipi, ILI9341_EN3GAM, 0x08);
+	mipi_dbi_command(mipi, MIPI_DCS_SET_GAMMA_CURVE, 0x01);
+	mipi_dbi_command(mipi, ILI9341_PGAMCTRL,
+		       0x1f, 0x1a, 0x18, 0x0a, 0x0f, 0x06, 0x45, 0x87,
+		       0x32, 0x0a, 0x07, 0x02, 0x07, 0x05, 0x00);
+	mipi_dbi_command(mipi, ILI9341_NGAMCTRL,
+		       0x00, 0x25, 0x27, 0x05, 0x10, 0x09, 0x3a, 0x78,
+		       0x4d, 0x05, 0x18, 0x0d, 0x38, 0x3a, 0x1f);
+
+	/* DDRAM */
+	mipi_dbi_command(mipi, ILI9341_ETMOD, 0x07);
+
+	/* Display */
+	mipi_dbi_command(mipi, ILI9341_DISCTRL, 0x0a, 0x82, 0x27, 0x00);
+	mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
+	msleep(100);
+
+	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
+	msleep(100);
+
+	return 0;
+}
+
+static void mi0283qt_fini(void *data)
+{
+	struct mipi_dbi *mipi = data;
+
+	DRM_DEBUG_KMS("\n");
+	regulator_disable(mipi->regulator);
+}
+
+static const struct drm_simple_display_pipe_funcs mi0283qt_pipe_funcs = {
+	.enable = mipi_dbi_pipe_enable,
+	.disable = mipi_dbi_pipe_disable,
+	.update = tinydrm_display_pipe_update,
+	.prepare_fb = tinydrm_display_pipe_prepare_fb,
+};
+
+static const struct drm_display_mode mi0283qt_mode = {
+	TINYDRM_MODE(320, 240, 58, 43),
+};
+
+static struct drm_driver mi0283qt_driver = {
+	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
+				  DRIVER_ATOMIC,
+	TINYDRM_GEM_DRIVER_OPS,
+	.lastclose		= tinydrm_lastclose,
+	.debugfs_init		= mipi_dbi_debugfs_init,
+	.name			= "mi0283qt",
+	.desc			= "Multi-Inno MI0283QT",
+	.date			= "20160614",
+	.major			= 1,
+	.minor			= 0,
+};
+
+static const struct of_device_id mi0283qt_of_match[] = {
+	{ .compatible = "multi-inno,mi0283qt" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mi0283qt_of_match);
+
+static const struct spi_device_id mi0283qt_id[] = {
+	{ "mi0283qt", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, mi0283qt_id);
+
+static int mi0283qt_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct tinydrm_device *tdev;
+	struct mipi_dbi *mipi;
+	struct gpio_desc *dc;
+	u32 rotation = 0;
+	int ret;
+
+	mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
+	if (!mipi)
+		return -ENOMEM;
+
+	mipi->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(mipi->reset)) {
+		dev_err(dev, "Failed to get gpio 'reset'\n");
+		return PTR_ERR(mipi->reset);
+	}
+
+	dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
+	if (IS_ERR(dc)) {
+		dev_err(dev, "Failed to get gpio 'dc'\n");
+		return PTR_ERR(dc);
+	}
+
+	mipi->regulator = devm_regulator_get(dev, "power");
+	if (IS_ERR(mipi->regulator))
+		return PTR_ERR(mipi->regulator);
+
+	mipi->backlight = tinydrm_of_find_backlight(dev);
+	if (IS_ERR(mipi->backlight))
+		return PTR_ERR(mipi->backlight);
+
+	device_property_read_u32(dev, "rotation", &rotation);
+
+	ret = mipi_dbi_spi_init(spi, mipi, dc, &mi0283qt_pipe_funcs,
+				&mi0283qt_driver, &mi0283qt_mode, rotation);
+	if (ret)
+		return ret;
+
+	ret = mi0283qt_init(mipi);
+	if (ret)
+		return ret;
+
+	/* use devres to fini after drm unregister (drv->remove is before) */
+	ret = devm_add_action(dev, mi0283qt_fini, mipi);
+	if (ret) {
+		mi0283qt_fini(mipi);
+		return ret;
+	}
+
+	tdev = &mipi->tinydrm;
+
+	ret = devm_tinydrm_register(tdev);
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, mipi);
+
+	DRM_DEBUG_DRIVER("Initialized %s:%s @%uMHz on minor %d\n",
+			 tdev->drm->driver->name, dev_name(dev),
+			 spi->max_speed_hz / 1000000,
+			 tdev->drm->primary->index);
+
+	return 0;
+}
+
+static void mi0283qt_shutdown(struct spi_device *spi)
+{
+	struct mipi_dbi *mipi = spi_get_drvdata(spi);
+
+	tinydrm_shutdown(&mipi->tinydrm);
+}
+
+static int __maybe_unused mi0283qt_pm_suspend(struct device *dev)
+{
+	struct mipi_dbi *mipi = dev_get_drvdata(dev);
+	int ret;
+
+	ret = tinydrm_suspend(&mipi->tinydrm);
+	if (ret)
+		return ret;
+
+	mi0283qt_fini(mipi);
+
+	return 0;
+}
+
+static int __maybe_unused mi0283qt_pm_resume(struct device *dev)
+{
+	struct mipi_dbi *mipi = dev_get_drvdata(dev);
+	int ret;
+
+	ret = mi0283qt_init(mipi);
+	if (ret)
+		return ret;
+
+	return tinydrm_resume(&mipi->tinydrm);
+}
+
+static const struct dev_pm_ops mi0283qt_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(mi0283qt_pm_suspend, mi0283qt_pm_resume)
+};
+
+static struct spi_driver mi0283qt_spi_driver = {
+	.driver = {
+		.name = "mi0283qt",
+		.owner = THIS_MODULE,
+		.of_match_table = mi0283qt_of_match,
+		.pm = &mi0283qt_pm_ops,
+	},
+	.id_table = mi0283qt_id,
+	.probe = mi0283qt_probe,
+	.shutdown = mi0283qt_shutdown,
+};
+module_spi_driver(mi0283qt_spi_driver);
+
+MODULE_DESCRIPTION("Multi-Inno MI0283QT DRM driver");
+MODULE_AUTHOR("Noralf Trønnes");
+MODULE_LICENSE("GPL");

include/drm/tinydrm/ili9341.h

+/*
+ * ILI9341 LCD controller
+ *
+ * Copyright 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_ILI9341_H
+#define __LINUX_ILI9341_H
+
+#define ILI9341_FRMCTR1    0xb1
+#define ILI9341_FRMCTR2    0xb2
+#define ILI9341_FRMCTR3    0xb3
+#define ILI9341_INVTR      0xb4
+#define ILI9341_PRCTR      0xb5
+#define ILI9341_DISCTRL    0xb6
+#define ILI9341_ETMOD      0xb7
+
+#define ILI9341_PWCTRL1    0xc0
+#define ILI9341_PWCTRL2    0xc1
+#define ILI9341_VMCTRL1    0xc5
+#define ILI9341_VMCTRL2    0xc7
+#define ILI9341_PWCTRLA    0xcb
+#define ILI9341_PWCTRLB    0xcf
+
+#define ILI9341_RDID1      0xda
+#define ILI9341_RDID2      0xdb
+#define ILI9341_RDID3      0xdc
+#define ILI9341_RDID4      0xd3
+
+#define ILI9341_PGAMCTRL   0xe0
+#define ILI9341_NGAMCTRL   0xe1
+#define ILI9341_DGAMCTRL1  0xe2
+#define ILI9341_DGAMCTRL2  0xe3
+#define ILI9341_DTCTRLA    0xe8
+#define ILI9341_DTCTRLB    0xea
+#define ILI9341_PWRSEQ     0xed
+
+#define ILI9341_EN3GAM     0xf2
+#define ILI9341_IFCTRL     0xf6
+#define ILI9341_PUMPCTRL   0xf7
+
+#define ILI9341_MADCTL_MH  BIT(2)
+#define ILI9341_MADCTL_BGR BIT(3)
+#define ILI9341_MADCTL_ML  BIT(4)
+#define ILI9341_MADCTL_MV  BIT(5)
+#define ILI9341_MADCTL_MX  BIT(6)
+#define ILI9341_MADCTL_MY  BIT(7)
+
+#endif /* __LINUX_ILI9341_H */

include/drm/tinydrm/mipi-dbi.h

+/*
+ * MIPI Display Bus Interface (DBI) LCD controller support
+ *
+ * Copyright 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_MIPI_DBI_H
+#define __LINUX_MIPI_DBI_H
+
+#include <drm/tinydrm/tinydrm.h>
+
+struct spi_device;
+struct gpio_desc;
+struct regulator;
+
+/**
+ * struct mipi_dbi - MIPI DBI controller
+ * @tinydrm: tinydrm base
+ * @spi: SPI device
+ * @enabled: Pipeline is enabled
+ * @cmdlock: Command lock
+ * @command: Bus specific callback executing commands.
+ * @read_commands: Array of read commands terminated by a zero entry.
+ *                 Reading is disabled if this is NULL.
+ * @dc: Optional D/C gpio.
+ * @tx_buf: Buffer used for transfer (copy clip rect area)
+ * @tx_buf9: Buffer used for Option 1 9-bit conversion
+ * @tx_buf9_len: Size of tx_buf9.
+ * @swap_bytes: Swap bytes in buffer before transfer
+ * @reset: Optional reset gpio
+ * @rotation: initial rotation in degrees Counter Clock Wise
+ * @backlight: backlight device (optional)
+ * @regulator: power regulator (optional)
+ */
+struct mipi_dbi {
+	struct tinydrm_device tinydrm;
+	struct spi_device *spi;
+	bool enabled;
+	struct mutex cmdlock;
+	int (*command)(struct mipi_dbi *mipi, u8 cmd, u8 *param, size_t num);
+	const u8 *read_commands;
+	struct gpio_desc *dc;
+	u16 *tx_buf;
+	void *tx_buf9;
+	size_t tx_buf9_len;
+	bool swap_bytes;
+	struct gpio_desc *reset;
+	unsigned int rotation;
+	struct backlight_device *backlight;
+	struct regulator *regulator;
+};
+
+static inline struct mipi_dbi *
+mipi_dbi_from_tinydrm(struct tinydrm_device *tdev)
+{
+	return container_of(tdev, struct mipi_dbi, tinydrm);
+}
+
+int mipi_dbi_spi_init(struct spi_device *spi, struct mipi_dbi *mipi,
+		      struct gpio_desc *dc,
+		      const struct drm_simple_display_pipe_funcs *pipe_funcs,
+		      struct drm_driver *driver,
+		      const struct drm_display_mode *mode,
+		      unsigned int rotation);
+int mipi_dbi_init(struct device *dev, struct mipi_dbi *mipi,
+		  const struct drm_simple_display_pipe_funcs *pipe_funcs,
+		  struct drm_driver *driver,
+		  const struct drm_display_mode *mode, unsigned int rotation);
+void mipi_dbi_pipe_enable(struct drm_simple_display_pipe *pipe,
+			  struct drm_crtc_state *crtc_state);
+void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe);
+void mipi_dbi_hw_reset(struct mipi_dbi *mipi);
+bool mipi_dbi_display_is_on(struct mipi_dbi *mipi);
+
+int mipi_dbi_command_read(struct mipi_dbi *mipi, u8 cmd, u8 *val);
+int mipi_dbi_command_buf(struct mipi_dbi *mipi, u8 cmd, u8 *data, size_t len);
+
+/**
+ * mipi_dbi_command - MIPI DCS command with optional parameter(s)
+ * @mipi: MIPI structure
+ * @cmd: Command
+ * @seq...: Optional parameter(s)
+ *
+ * Send MIPI DCS command to the controller. Use mipi_dbi_command_read() for
+ * get/read.
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+#define mipi_dbi_command(mipi, cmd, seq...) \
+({ \
+	u8 d[] = { seq }; \
+	mipi_dbi_command_buf(mipi, cmd, d, ARRAY_SIZE(d)); \
+})
+
+#ifdef CONFIG_DEBUG_FS
+int mipi_dbi_debugfs_init(struct drm_minor *minor);
+#else
+#define mipi_dbi_debugfs_init		NULL
+#endif
+
+#endif /* __LINUX_MIPI_DBI_H */

include/drm/tinydrm/tinydrm-helpers.h

+/*
+ * 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_HELPERS_H
+#define __LINUX_TINYDRM_HELPERS_H
+
+struct backlight_device;
+struct tinydrm_device;
+struct drm_clip_rect;
+struct spi_transfer;
+struct spi_message;
+struct spi_device;
+struct device;
+
+/**
+ * tinydrm_machine_little_endian - Machine is little endian
+ *
+ * Returns:
+ * true if *defined(__LITTLE_ENDIAN)*, false otherwise
+ */
+static inline bool tinydrm_machine_little_endian(void)
+{
+#if defined(__LITTLE_ENDIAN)
+	return true;
+#else
+	return false;
+#endif
+}
+
+bool tinydrm_merge_clips(struct drm_clip_rect *dst,
+			 struct drm_clip_rect *src, unsigned int num_clips,
+			 unsigned int flags, u32 max_width, u32 max_height);
+void tinydrm_memcpy(void *dst, void *vaddr, struct drm_framebuffer *fb,
+		    struct drm_clip_rect *clip);
+void tinydrm_swab16(u16 *dst, void *vaddr, struct drm_framebuffer *fb,
+		    struct drm_clip_rect *clip);
+void tinydrm_xrgb8888_to_rgb565(u16 *dst, void *vaddr,
+				struct drm_framebuffer *fb,
+				struct drm_clip_rect *clip, bool swap);
+
+#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
+struct backlight_device *tinydrm_of_find_backlight(struct device *dev);
+int tinydrm_enable_backlight(struct backlight_device *backlight);
+int tinydrm_disable_backlight(struct backlight_device *backlight);
+#else
+static inline struct backlight_device *
+tinydrm_of_find_backlight(struct device *dev)
+{
+	return NULL;
+}
+
+static inline int tinydrm_enable_backlight(struct backlight_device *backlight)
+{
+	return 0;
+}
+
+static inline int
+tinydrm_disable_backlight(struct backlight_device *backlight)
+{
+	return 0;
+}
+#endif
+
+size_t tinydrm_spi_max_transfer_size(struct spi_device *spi, size_t max_len);
+bool tinydrm_spi_bpw_supported(struct spi_device *spi, u8 bpw);
+int tinydrm_spi_transfer(struct spi_device *spi, u32 speed_hz,
+			 struct spi_transfer *header, u8 bpw, const void *buf,
+			 size_t len);
+void _tinydrm_dbg_spi_message(struct spi_device *spi, struct spi_message *m);
+
+#ifdef DEBUG
+/**
+ * tinydrm_dbg_spi_message - Dump SPI message
+ * @spi: SPI device
+ * @m: SPI message
+ *
+ * Dumps info about the transfers in a SPI message including buffer content.
+ * DEBUG has to be defined for this function to be enabled alongside setting
+ * the DRM_UT_DRIVER bit of &drm_debug.
+ */
+static inline void tinydrm_dbg_spi_message(struct spi_device *spi,
+					   struct spi_message *m)
+{
+	if (drm_debug & DRM_UT_DRIVER)
+		_tinydrm_dbg_spi_message(spi, m);
+}
+#else
+static inline void tinydrm_dbg_spi_message(struct spi_device *spi,
+					   struct spi_message *m)
+{
+}
+#endif /* DEBUG */
+
+#endif /* __LINUX_TINYDRM_HELPERS_H */

include/drm/tinydrm/tinydrm.h

+/*
+ * 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 */