diff mbox

[v2,2/3] drm: simpledrm: add fbdev fallback support

Message ID 1470411883-3534-3-git-send-email-noralf@tronnes.org (mailing list archive)
State New, archived
Headers show

Commit Message

Noralf Trønnes Aug. 5, 2016, 3:44 p.m. UTC
Create a simple fbdev device during SimpleDRM setup so legacy user-space
and fbcon can use it.

Original work by David Herrmann.

Cc: dh.herrmann@gmail.com
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---

Changes from version 1:
  No changes

Changes from previous version:
- Remove the DRM_SIMPLEDRM_FBDEV kconfig option and use DRM_FBDEV_EMULATION
- Suspend fbcon/fbdev when the pipeline is enabled, resume in lastclose
- Add FBINFO_CAN_FORCE_OUTPUT flag so we get oops'es on the console

 drivers/gpu/drm/simpledrm/Kconfig           |   3 +
 drivers/gpu/drm/simpledrm/Makefile          |   1 +
 drivers/gpu/drm/simpledrm/simpledrm.h       |  24 +++++
 drivers/gpu/drm/simpledrm/simpledrm_drv.c   |   4 +
 drivers/gpu/drm/simpledrm/simpledrm_fbdev.c | 160 ++++++++++++++++++++++++++++
 drivers/gpu/drm/simpledrm/simpledrm_kms.c   |  12 +++
 6 files changed, 204 insertions(+)
 create mode 100644 drivers/gpu/drm/simpledrm/simpledrm_fbdev.c

--
2.8.2

Comments

Paul Gortmaker Aug. 5, 2016, 10:38 p.m. UTC | #1
On Fri, Aug 5, 2016 at 11:44 AM, Noralf Trønnes <noralf@tronnes.org> wrote:
> Create a simple fbdev device during SimpleDRM setup so legacy user-space
> and fbcon can use it.
>
> Original work by David Herrmann.
>
> Cc: dh.herrmann@gmail.com
> Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
> ---
>
> Changes from version 1:
>   No changes
>
> Changes from previous version:
> - Remove the DRM_SIMPLEDRM_FBDEV kconfig option and use DRM_FBDEV_EMULATION
> - Suspend fbcon/fbdev when the pipeline is enabled, resume in lastclose
> - Add FBINFO_CAN_FORCE_OUTPUT flag so we get oops'es on the console
>
>  drivers/gpu/drm/simpledrm/Kconfig           |   3 +
>  drivers/gpu/drm/simpledrm/Makefile          |   1 +
>  drivers/gpu/drm/simpledrm/simpledrm.h       |  24 +++++
>  drivers/gpu/drm/simpledrm/simpledrm_drv.c   |   4 +
>  drivers/gpu/drm/simpledrm/simpledrm_fbdev.c | 160 ++++++++++++++++++++++++++++
>  drivers/gpu/drm/simpledrm/simpledrm_kms.c   |  12 +++
>  6 files changed, 204 insertions(+)
>  create mode 100644 drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
>
> diff --git a/drivers/gpu/drm/simpledrm/Kconfig b/drivers/gpu/drm/simpledrm/Kconfig
> index f45b25d..9454536 100644
> --- a/drivers/gpu/drm/simpledrm/Kconfig
> +++ b/drivers/gpu/drm/simpledrm/Kconfig
> @@ -13,6 +13,9 @@ config DRM_SIMPLEDRM
>           SimpleDRM supports "simple-framebuffer" DeviceTree objects and
>           compatible platform framebuffers.
>
> +         If fbdev support is enabled, this driver will also provide an fbdev
> +         compatibility layer.
> +
>           If unsure, say Y.
>
>           To compile this driver as a module, choose M here: the
> diff --git a/drivers/gpu/drm/simpledrm/Makefile b/drivers/gpu/drm/simpledrm/Makefile
> index f6a62dc..7087245 100644
> --- a/drivers/gpu/drm/simpledrm/Makefile
> +++ b/drivers/gpu/drm/simpledrm/Makefile
> @@ -1,4 +1,5 @@
>  simpledrm-y := simpledrm_drv.o simpledrm_kms.o simpledrm_gem.o \
>                 simpledrm_damage.o
> +simpledrm-$(CONFIG_DRM_FBDEV_EMULATION) += simpledrm_fbdev.o
>
>  obj-$(CONFIG_DRM_SIMPLEDRM) := simpledrm.o
> diff --git a/drivers/gpu/drm/simpledrm/simpledrm.h b/drivers/gpu/drm/simpledrm/simpledrm.h
> index f9f082c..eb18d59 100644
> --- a/drivers/gpu/drm/simpledrm/simpledrm.h
> +++ b/drivers/gpu/drm/simpledrm/simpledrm.h
> @@ -30,6 +30,7 @@ struct sdrm_device {
>         struct drm_device *ddev;
>         struct drm_simple_display_pipe pipe;
>         struct drm_connector conn;
> +       struct fb_info *fbdev;
>
>         /* framebuffer information */
>         const struct simplefb_format *fb_sformat;
> @@ -52,6 +53,7 @@ struct sdrm_device {
>  #endif
>  };
>
> +void sdrm_lastclose(struct drm_device *ddev);
>  int sdrm_drm_modeset_init(struct sdrm_device *sdrm);
>  int sdrm_drm_mmap(struct file *filp, struct vm_area_struct *vma);
>
> @@ -93,4 +95,26 @@ struct sdrm_framebuffer {
>
>  #define to_sdrm_fb(x) container_of(x, struct sdrm_framebuffer, base)
>
> +#ifdef CONFIG_DRM_FBDEV_EMULATION
> +
> +void sdrm_fbdev_init(struct sdrm_device *sdrm);
> +void sdrm_fbdev_cleanup(struct sdrm_device *sdrm);
> +void sdrm_fbdev_set_suspend(struct sdrm_device *sdrm, int state);
> +
> +#else
> +
> +static inline void sdrm_fbdev_init(struct sdrm_device *sdrm)
> +{
> +}
> +
> +static inline void sdrm_fbdev_cleanup(struct sdrm_device *sdrm)
> +{
> +}
> +
> +static inline void sdrm_fbdev_set_suspend(struct sdrm_device *sdrm, int state)
> +{
> +}
> +
> +#endif
> +
>  #endif /* SDRM_DRV_H */
> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_drv.c b/drivers/gpu/drm/simpledrm/simpledrm_drv.c
> index 35296d2..88ad717c 100644
> --- a/drivers/gpu/drm/simpledrm/simpledrm_drv.c
> +++ b/drivers/gpu/drm/simpledrm/simpledrm_drv.c
> @@ -41,6 +41,7 @@ static struct drm_driver sdrm_drm_driver = {
>         .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
>                            DRIVER_ATOMIC,
>         .fops = &sdrm_drm_fops,
> +       .lastclose = sdrm_lastclose,
>
>         .gem_free_object = sdrm_gem_free_object,
>         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> @@ -447,6 +448,8 @@ static int sdrm_simplefb_probe(struct platform_device *pdev)
>         if (ret)
>                 goto err_regulators;
>
> +       sdrm_fbdev_init(ddev->dev_private);
> +
>         DRM_INFO("Initialized %s on minor %d\n", ddev->driver->name,
>                  ddev->primary->index);
>
> @@ -472,6 +475,7 @@ static int sdrm_simplefb_remove(struct platform_device *pdev)
>         struct drm_device *ddev = platform_get_drvdata(pdev);
>         struct sdrm_device *sdrm = ddev->dev_private;
>
> +       sdrm_fbdev_cleanup(sdrm);
>         drm_dev_unregister(ddev);
>         drm_mode_config_cleanup(ddev);
>
> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c b/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
> new file mode 100644
> index 0000000..b83646b
> --- /dev/null
> +++ b/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
> @@ -0,0 +1,160 @@
> +/*
> + * SimpleDRM firmware framebuffer driver
> + * Copyright (c) 2012-2014 David Herrmann <dh.herrmann@gmail.com>
> + *
> + * 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.
> + */
> +
> +/*
> + * fbdev compatibility layer
> + * We provide a basic fbdev device for the same framebuffer that is used for
> + * the pseudo CRTC.
> + */
> +
> +#include <linux/console.h>
> +#include <linux/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/module.h>

You should not need module.h  here since this file is not doing the
module_init or module_exit or MODULE_ALIAS etc etc.

An empty file with just module.h in it outputs about 750k of goo
from cpp, so it is best avoided wherever not strictly needed.

Thanks,
Paul.
--

> +#include <linux/string.h>
> +#include <linux/fb.h>
> +#include "simpledrm.h"
> +
Noralf Trønnes Aug. 8, 2016, 1:38 p.m. UTC | #2
Den 06.08.2016 00:38, skrev Paul Gortmaker:
> On Fri, Aug 5, 2016 at 11:44 AM, Noralf Trønnes <noralf@tronnes.org> wrote:
>> Create a simple fbdev device during SimpleDRM setup so legacy user-space
>> and fbcon can use it.
>>
>> Original work by David Herrmann.
>>
>> Cc: dh.herrmann@gmail.com
>> Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
>> ---
>>
>> Changes from version 1:
>>    No changes
>>
>> Changes from previous version:
>> - Remove the DRM_SIMPLEDRM_FBDEV kconfig option and use DRM_FBDEV_EMULATION
>> - Suspend fbcon/fbdev when the pipeline is enabled, resume in lastclose
>> - Add FBINFO_CAN_FORCE_OUTPUT flag so we get oops'es on the console

<snip>

>> diff --git a/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c b/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
>> new file mode 100644
>> index 0000000..b83646b
>> --- /dev/null
>> +++ b/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
>> @@ -0,0 +1,160 @@
>> +/*
>> + * SimpleDRM firmware framebuffer driver
>> + * Copyright (c) 2012-2014 David Herrmann <dh.herrmann@gmail.com>
>> + *
>> + * 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.
>> + */
>> +
>> +/*
>> + * fbdev compatibility layer
>> + * We provide a basic fbdev device for the same framebuffer that is used for
>> + * the pseudo CRTC.
>> + */
>> +
>> +#include <linux/console.h>
>> +#include <linux/errno.h>
>> +#include <linux/kernel.h>
>> +#include <linux/mm.h>
>> +#include <linux/module.h>
> You should not need module.h  here since this file is not doing the
> module_init or module_exit or MODULE_ALIAS etc etc.
>
> An empty file with just module.h in it outputs about 750k of goo
> from cpp, so it is best avoided wherever not strictly needed.

I've never thought of superfluous includes in terms of compile time before,
but that makes sense, especially on a large project like this.

Thanks,
Noralf.


> Thanks,
> Paul.
> --
>
>> +#include <linux/string.h>
>> +#include <linux/fb.h>
>> +#include "simpledrm.h"
>> +
diff mbox

Patch

diff --git a/drivers/gpu/drm/simpledrm/Kconfig b/drivers/gpu/drm/simpledrm/Kconfig
index f45b25d..9454536 100644
--- a/drivers/gpu/drm/simpledrm/Kconfig
+++ b/drivers/gpu/drm/simpledrm/Kconfig
@@ -13,6 +13,9 @@  config DRM_SIMPLEDRM
 	  SimpleDRM supports "simple-framebuffer" DeviceTree objects and
 	  compatible platform framebuffers.

+	  If fbdev support is enabled, this driver will also provide an fbdev
+	  compatibility layer.
+
 	  If unsure, say Y.

 	  To compile this driver as a module, choose M here: the
diff --git a/drivers/gpu/drm/simpledrm/Makefile b/drivers/gpu/drm/simpledrm/Makefile
index f6a62dc..7087245 100644
--- a/drivers/gpu/drm/simpledrm/Makefile
+++ b/drivers/gpu/drm/simpledrm/Makefile
@@ -1,4 +1,5 @@ 
 simpledrm-y :=	simpledrm_drv.o simpledrm_kms.o simpledrm_gem.o \
 		simpledrm_damage.o
+simpledrm-$(CONFIG_DRM_FBDEV_EMULATION) += simpledrm_fbdev.o

 obj-$(CONFIG_DRM_SIMPLEDRM) := simpledrm.o
diff --git a/drivers/gpu/drm/simpledrm/simpledrm.h b/drivers/gpu/drm/simpledrm/simpledrm.h
index f9f082c..eb18d59 100644
--- a/drivers/gpu/drm/simpledrm/simpledrm.h
+++ b/drivers/gpu/drm/simpledrm/simpledrm.h
@@ -30,6 +30,7 @@  struct sdrm_device {
 	struct drm_device *ddev;
 	struct drm_simple_display_pipe pipe;
 	struct drm_connector conn;
+	struct fb_info *fbdev;

 	/* framebuffer information */
 	const struct simplefb_format *fb_sformat;
@@ -52,6 +53,7 @@  struct sdrm_device {
 #endif
 };

+void sdrm_lastclose(struct drm_device *ddev);
 int sdrm_drm_modeset_init(struct sdrm_device *sdrm);
 int sdrm_drm_mmap(struct file *filp, struct vm_area_struct *vma);

@@ -93,4 +95,26 @@  struct sdrm_framebuffer {

 #define to_sdrm_fb(x) container_of(x, struct sdrm_framebuffer, base)

+#ifdef CONFIG_DRM_FBDEV_EMULATION
+
+void sdrm_fbdev_init(struct sdrm_device *sdrm);
+void sdrm_fbdev_cleanup(struct sdrm_device *sdrm);
+void sdrm_fbdev_set_suspend(struct sdrm_device *sdrm, int state);
+
+#else
+
+static inline void sdrm_fbdev_init(struct sdrm_device *sdrm)
+{
+}
+
+static inline void sdrm_fbdev_cleanup(struct sdrm_device *sdrm)
+{
+}
+
+static inline void sdrm_fbdev_set_suspend(struct sdrm_device *sdrm, int state)
+{
+}
+
+#endif
+
 #endif /* SDRM_DRV_H */
diff --git a/drivers/gpu/drm/simpledrm/simpledrm_drv.c b/drivers/gpu/drm/simpledrm/simpledrm_drv.c
index 35296d2..88ad717c 100644
--- a/drivers/gpu/drm/simpledrm/simpledrm_drv.c
+++ b/drivers/gpu/drm/simpledrm/simpledrm_drv.c
@@ -41,6 +41,7 @@  static struct drm_driver sdrm_drm_driver = {
 	.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
 			   DRIVER_ATOMIC,
 	.fops = &sdrm_drm_fops,
+	.lastclose = sdrm_lastclose,

 	.gem_free_object = sdrm_gem_free_object,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
@@ -447,6 +448,8 @@  static int sdrm_simplefb_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_regulators;

+	sdrm_fbdev_init(ddev->dev_private);
+
 	DRM_INFO("Initialized %s on minor %d\n", ddev->driver->name,
 		 ddev->primary->index);

@@ -472,6 +475,7 @@  static int sdrm_simplefb_remove(struct platform_device *pdev)
 	struct drm_device *ddev = platform_get_drvdata(pdev);
 	struct sdrm_device *sdrm = ddev->dev_private;

+	sdrm_fbdev_cleanup(sdrm);
 	drm_dev_unregister(ddev);
 	drm_mode_config_cleanup(ddev);

diff --git a/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c b/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
new file mode 100644
index 0000000..b83646b
--- /dev/null
+++ b/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
@@ -0,0 +1,160 @@ 
+/*
+ * SimpleDRM firmware framebuffer driver
+ * Copyright (c) 2012-2014 David Herrmann <dh.herrmann@gmail.com>
+ *
+ * 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.
+ */
+
+/*
+ * fbdev compatibility layer
+ * We provide a basic fbdev device for the same framebuffer that is used for
+ * the pseudo CRTC.
+ */
+
+#include <linux/console.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fb.h>
+#include "simpledrm.h"
+
+struct sdrm_fbdev {
+	u32 palette[16];
+};
+
+static int sdrm_fbdev_setcolreg(u_int regno, u_int red, u_int green,
+				u_int blue, u_int transp, struct fb_info *info)
+{
+	u32 *pal = info->pseudo_palette;
+	u32 cr = red >> (16 - info->var.red.length);
+	u32 cg = green >> (16 - info->var.green.length);
+	u32 cb = blue >> (16 - info->var.blue.length);
+	u32 value;
+
+	if (regno >= 16)
+		return -EINVAL;
+
+	value = (cr << info->var.red.offset) |
+		(cg << info->var.green.offset) |
+		(cb << info->var.blue.offset);
+
+	if (info->var.transp.length > 0) {
+		u32 mask = (1 << info->var.transp.length) - 1;
+
+		mask <<= info->var.transp.offset;
+		value |= mask;
+	}
+
+	pal[regno] = value;
+
+	return 0;
+}
+
+static struct fb_ops sdrm_fbdev_ops = {
+	.owner		= THIS_MODULE,
+	.fb_setcolreg	= sdrm_fbdev_setcolreg,
+	.fb_fillrect	= cfb_fillrect,
+	.fb_copyarea	= cfb_copyarea,
+	.fb_imageblit	= cfb_imageblit,
+};
+
+void sdrm_fbdev_init(struct sdrm_device *sdrm)
+{
+	struct sdrm_fbdev *fb;
+	struct fb_info *info;
+	int ret;
+
+	if (fb_get_options("simpledrmfb", NULL))
+		return;
+
+	info = framebuffer_alloc(sizeof(struct sdrm_fbdev), sdrm->ddev->dev);
+	if (!info)
+		goto err_out;
+
+	fb = info->par;
+	info->flags = FBINFO_DEFAULT | FBINFO_MISC_FIRMWARE |
+		      FBINFO_CAN_FORCE_OUTPUT;
+	info->pseudo_palette = fb->palette;
+	info->fbops = &sdrm_fbdev_ops;
+	info->screen_base = sdrm->fb_map;
+
+	strncpy(info->fix.id, "simpledrmfb", 15);
+	info->fix.type = FB_TYPE_PACKED_PIXELS;
+	info->fix.visual = FB_VISUAL_TRUECOLOR;
+	info->fix.accel = FB_ACCEL_NONE;
+	info->fix.smem_start = (unsigned long)sdrm->fb_base;
+	info->fix.smem_len = sdrm->fb_size;
+	info->fix.line_length = sdrm->fb_stride;
+
+	info->var.activate = FB_ACTIVATE_NOW;
+	info->var.vmode = FB_VMODE_NONINTERLACED;
+	info->var.bits_per_pixel = sdrm->fb_bpp;
+	info->var.height = -1;
+	info->var.width = -1;
+	info->var.xres = sdrm->fb_width;
+	info->var.yres = sdrm->fb_height;
+	info->var.xres_virtual = info->var.xres;
+	info->var.yres_virtual = info->var.yres;
+	info->var.red = sdrm->fb_sformat->red;
+	info->var.green = sdrm->fb_sformat->green;
+	info->var.blue = sdrm->fb_sformat->blue;
+	info->var.transp = sdrm->fb_sformat->transp;
+
+	/* some dummy values for timing to make fbset happy */
+	info->var.pixclock = 10000000 / info->var.xres * 1000 / info->var.yres;
+	info->var.left_margin = (info->var.xres / 8) & 0xf8;
+	info->var.right_margin = 32;
+	info->var.upper_margin = 16;
+	info->var.lower_margin = 4;
+	info->var.hsync_len = (info->var.xres / 8) & 0xf8;
+	info->var.vsync_len = 4;
+
+	ret = register_framebuffer(info);
+	if (ret < 0)
+		goto err_free;
+
+	sdrm->fbdev = info;
+	dev_info(sdrm->ddev->dev, "fbdev frontend %s as fb%d\n",
+		 info->fix.id, info->node);
+
+	return;
+
+err_free:
+	framebuffer_release(info);
+err_out:
+	dev_warn(sdrm->ddev->dev, "cannot create fbdev frontend\n");
+}
+
+void sdrm_fbdev_cleanup(struct sdrm_device *sdrm)
+{
+	struct fb_info *info;
+
+	if (!sdrm->fbdev)
+		return;
+
+	info = sdrm->fbdev;
+	sdrm->fbdev = NULL;
+
+	dev_info(sdrm->ddev->dev, "remove fbdev frontend %s (fb%d)\n",
+		 info->fix.id, info->node);
+
+	if (unregister_framebuffer(info))
+		dev_err(sdrm->ddev->dev, "unregister_framebuffer() failed, leaking fw-fb\n");
+	else
+		framebuffer_release(info);
+}
+
+void sdrm_fbdev_set_suspend(struct sdrm_device *sdrm, int state)
+{
+	if (!sdrm->fbdev)
+		return;
+
+	console_lock();
+	fb_set_suspend(sdrm->fbdev, state);
+	console_unlock();
+}
diff --git a/drivers/gpu/drm/simpledrm/simpledrm_kms.c b/drivers/gpu/drm/simpledrm/simpledrm_kms.c
index 193c3c3..5f53624 100644
--- a/drivers/gpu/drm/simpledrm/simpledrm_kms.c
+++ b/drivers/gpu/drm/simpledrm/simpledrm_kms.c
@@ -25,6 +25,14 @@  static const uint32_t sdrm_formats[] = {
 	DRM_FORMAT_XRGB8888,
 };

+void sdrm_lastclose(struct drm_device *ddev)
+{
+	struct sdrm_device *sdrm = ddev->dev_private;
+
+	/* resume fbcon/fbdev */
+	sdrm_fbdev_set_suspend(sdrm, 0);
+}
+
 static int sdrm_conn_get_modes(struct drm_connector *conn)
 {
 	struct sdrm_device *sdrm = conn->dev->dev_private;
@@ -98,7 +106,11 @@  static void sdrm_crtc_send_vblank_event(struct drm_crtc *crtc)
 static void sdrm_display_pipe_enable(struct drm_simple_display_pipe *pipe,
 				     struct drm_crtc_state *crtc_state)
 {
+	struct sdrm_device *sdrm = pipe_to_sdrm(pipe);
+
 	sdrm_crtc_send_vblank_event(&pipe->crtc);
+	/* suspend fbcon/fbdev */
+	sdrm_fbdev_set_suspend(sdrm, 1);
 }

 static void sdrm_display_pipe_disable(struct drm_simple_display_pipe *pipe)