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

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"