Re: [PATCHv4 3/3] DRM:ivip Intel FPGA Video and Image Processing Suite

[Laurent Pinchart]

Hi Hean Loong,

Thank you for the patch.

On Tuesday 01 Aug 2017 10:31:34 Hean Loong, Ong wrote:
> From: Ong Hean Loong <hean.loong.ong@xxxxxxxxx>
> 
> Driver for Intel FPGA Video and Image Processing
> Suite Frame Buffer II. The driver only supports the Intel
> Arria10 devkit and its variants. This driver can be either
> loaded staticlly or in modules. The OF device tree binding
> is located at:
> Documentation/devicetree/bindings/display/altr,vip-fb2.txt
> 
> Signed-off-by: Ong, Hean Loong <hean.loong.ong@xxxxxxxxx>
> ---
> V3:
> *Changes to fixing drm_simple_pipe
> *Used drm_fb_cma_get_gem_addr
> 
> V2:
> *Adding drm_simple_display_pipe_init
> ---
>  drivers/gpu/drm/Kconfig               |   2 +
>  drivers/gpu/drm/Makefile              |   1 +
>  drivers/gpu/drm/ivip/Kconfig          |  13 +++
>  drivers/gpu/drm/ivip/Makefile         |   9 ++
>  drivers/gpu/drm/ivip/intel_vip_conn.c |  96 ++++++++++++++++
>  drivers/gpu/drm/ivip/intel_vip_core.c | 183 ++++++++++++++++++++++++++++++
>  drivers/gpu/drm/ivip/intel_vip_drv.h  |  54 +++++++++
>  drivers/gpu/drm/ivip/intel_vip_of.c   | 204 +++++++++++++++++++++++++++++++
>  8 files changed, 562 insertions(+)
>  create mode 100644 drivers/gpu/drm/ivip/Kconfig
>  create mode 100644 drivers/gpu/drm/ivip/Makefile
>  create mode 100644 drivers/gpu/drm/ivip/intel_vip_conn.c
>  create mode 100644 drivers/gpu/drm/ivip/intel_vip_core.c
>  create mode 100644 drivers/gpu/drm/ivip/intel_vip_drv.h
>  create mode 100644 drivers/gpu/drm/ivip/intel_vip_of.c

[snip]

> diff --git a/drivers/gpu/drm/ivip/Kconfig b/drivers/gpu/drm/ivip/Kconfig
> new file mode 100644
> index 0000000..9a8c5ce
> --- /dev/null
> +++ b/drivers/gpu/drm/ivip/Kconfig
> @@ -0,0 +1,13 @@
> +config DRM_IVIP
> +	 tristate "Intel FGPA Video and Image Processing"
> +	 depends on DRM && OF
> +	 select DRM_GEM_CMA_HELPER
> +	 select DRM_KMS_HELPER
> +	 select DRM_KMS_FB_HELPER
> +	 select DRM_KMS_CMA_HELPER
> +	 help
> +	     Choose this option if you have a Intel FPGA Arria 10 system
> +	     and above with a Display Port IP. This does not support legacy
> +	     Intel FPGA Cyclone V display port. Currently only single frame
> +	     buffer is supported.

I think this should be fixed to upstream this driver.

> Note that ACPI and X_86 architecture is yet

ACPI on FPGA... I wonder if it could get any crazier than that :-)

> +	     to be supported.If M is selected the module would be called ivip.

s/.If/. If/

[snip]

> diff --git a/drivers/gpu/drm/ivip/intel_vip_core.c
> b/drivers/gpu/drm/ivip/intel_vip_core.c new file mode 100644
> index 0000000..ea85715
> --- /dev/null
> +++ b/drivers/gpu/drm/ivip/intel_vip_core.c
> @@ -0,0 +1,183 @@
> +/*
> + * intel_vip_core.c -- Intel Video and Image Processing(VIP)
> + * Frame Buffer II driver
> + *
> + * This driver supports the Intel VIP Frame Reader component.
> + * More info on the hardware can be found in the Intel Video
> + * and Image Processing Suite User Guide at this address
> + * http://www.altera.com/literature/ug/ug_vip.pdf.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> for + * more details.
> + *
> + * Authors:
> + * Ong, Hean-Loong <hean.loong.ong@xxxxxxxxx>
> + *
> + */
> +
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_fb_cma_helper.h>
> +#include <drm/drm_gem_cma_helper.h>
> +#include <drm/drm_plane_helper.h>
> +#include <drm/drm_simple_kms_helper.h>
> +
> +#include "intel_vip_drv.h"
> +
> +static void intelvipfb_enable(struct drm_simple_display_pipe *pipe,
> +	struct drm_crtc_state *crtc_state)
> +{
> +	/*
> +	 * The frameinfo variable has to correspond to the size of the VIP 
Suite
> +	 * Frame Reader register 7 which will determine the maximum size used
> +	 * in this frameinfo
> +	 */
> +
> +	u32 frameinfo;
> +	struct intelvipfb_priv *priv = pipe->plane.dev->dev_private;
> +	void __iomem *base = priv->base;
> +	struct drm_plane_state *state = pipe->plane.state;
> +	dma_addr_t addr;
> +
> +	addr = drm_fb_cma_get_gem_addr(state->fb, state, 0);
> +
> +	dev_info(pipe->plane.dev->dev, "Address 0x%x\n", addr);
> +
> +	frameinfo =
> +		  readl(base + INTELVIPFB_FRAME_READER) & 0x00ffffff;
> +	writel(frameinfo, base + INTELVIPFB_FRAME_INFO);
> +	writel(addr, base + INTELVIPFB_FRAME_START);
> +	/* Finally set the control register to 1 to start streaming */
> +	writel(1, base + INTELVIPFB_CONTROL);
> +}
> +
> +static void intelvipfb_disable(struct drm_simple_display_pipe *pipe)
> +{
> +	struct intelvipfb_priv *priv = pipe->plane.dev->dev_private;
> +	void __iomem *base = priv->base;

Missing blank line.

> +	/* set the control register to 0 to stop streaming */
> +	writel(0, base + INTELVIPFB_CONTROL);
> +}
> +
> +static const struct drm_mode_config_funcs intelvipfb_mode_config_funcs = {
> +	.fb_create = drm_fb_cma_create,
> +	.atomic_check = drm_atomic_helper_check,
> +	.atomic_commit = drm_atomic_helper_commit,
> +};
> +
> +static void intelvipfb_setup_mode_config(struct drm_device *drm)
> +{
> +	drm_mode_config_init(drm);
> +	drm->mode_config.funcs = &intelvipfb_mode_config_funcs;
> +}
> +
> +static int intelvipfb_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);
> +}
> +
> +static void intelvipfb_update(struct drm_simple_display_pipe *pipe,
> +		struct drm_plane_state *old_state)
> +{
> +	struct drm_crtc *crtc = &pipe->crtc;
> +
> +	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;
> +	}

This is not quite right. Userspace expects the driver to perform a page flip 
here, and you just signal page flip completion without doing anything.

> +}
> +
> +static struct drm_simple_display_pipe_funcs fbpriv_funcs = {
> +	.prepare_fb = intelvipfb_pipe_prepare_fb,
> +	.update = intelvipfb_update,
> +	.enable = intelvipfb_enable,
> +	.disable = intelvipfb_disable
> +};
> +
> +int intelvipfb_probe(struct device *dev, void __iomem *base)

You don't use the base argument, you can remove it.

> +{
> +	int retval;
> +	struct drm_device *drm;
> +	struct intelvipfb_priv *fbpriv = dev_get_drvdata(dev);
> +	struct drm_connector *connector;
> +

Extra blank line.

> +	u32 formats[] = {DRM_FORMAT_XRGB8888};
> +
> +	dev_set_drvdata(dev, fbpriv);

As fbpriv is obtained by a call to dev_get_drvdata(), this isn't needed.

A better option would be to pass the intelvipfb_priv pointer as an argument to 
this function.

> +	drm = fbpriv->drm;
> +
> +	drm->dev_private = fbpriv;
> +
> +	intelvipfb_setup_mode_config(drm);
> +
> +	connector = intelvipfb_conn_setup(drm);
> +	if (!connector) {
> +		dev_err(drm->dev, "Connector setup failed\n");
> +		goto err_mode_config;
> +	}
> +
> +	retval = drm_simple_display_pipe_init(drm, &fbpriv->pipe,
> +		&fbpriv_funcs, formats,
> +		ARRAY_SIZE(formats), connector);
> +	if (retval < 0) {
> +		dev_err(drm->dev, "Cannot setup simple display pipe\n");
> +		goto err_mode_config;
> +	}
> +
> +	fbpriv->fbcma = drm_fbdev_cma_init(drm,
> +		drm->mode_config.preferred_depth,
> +		drm->mode_config.num_connector);
> +
> +	drm_mode_config_reset(drm);
> +
> +	drm_dev_register(drm, 0);
> +
> +	return retval;
> +
> +err_mode_config:
> +
> +	drm_mode_config_cleanup(drm);
> +	return -ENODEV;
> +}
> +EXPORT_SYMBOL_GPL(intelvipfb_probe);

Why do you need to export this symbol ?

> +int intelvipfb_remove(struct device *dev)
> +{
> +	struct intelvipfb_priv *fbpriv = dev_get_drvdata(dev);
> +	struct drm_device *drm =  fbpriv->drm;
> +
> +	drm_dev_unregister(drm);
> +
> +	if (fbpriv->fbcma)
> +		drm_fbdev_cma_fini(fbpriv->fbcma);
> +
> +	drm_mode_config_cleanup(drm);
> +
> +	drm_dev_unref(drm);
> +
> +	devm_kfree(dev, fbpriv);

The whole point of devm_kzalloc() is that you don't need to free the memory at 
remove time.

> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(intelvipfb_remove);
> +
> +MODULE_AUTHOR("Ong, Hean-Loong <hean.loong.ong@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Intel VIP Frame Buffer II driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/gpu/drm/ivip/intel_vip_drv.h
> b/drivers/gpu/drm/ivip/intel_vip_drv.h new file mode 100644
> index 0000000..ebdbd50
> --- /dev/null
> +++ b/drivers/gpu/drm/ivip/intel_vip_drv.h
> @@ -0,0 +1,54 @@
> +/*
> + * Copyright (C) 2017 Intel Corporation.
> + *
> + * Intel Video and Image Processing(VIP) Frame Buffer II driver.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> for + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> with + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + *
> + * Authors:
> + * Ong, Hean-Loong <hean.loong.ong@xxxxxxxxx>
> + *
> + */
> +#ifndef _INTEL_VIP_DRV_H
> +#define _INTEL_VIP_DRV_H

Missing blank line.

> +#include <linux/io.h>
> +#include <linux/fb.h>

I don't think this header is needed.

> +#define DRIVER_NAME    "intelvipfb"
> +#define BYTES_PER_PIXEL        4
> +#define CRTC_NUM               1
> +#define CONN_NUM               1
> +
> +/* control registers */
> +#define INTELVIPFB_CONTROL             0
> +#define INTELVIPFB_STATUS              0x4
> +#define INTELVIPFB_INTERRUPT           0x8
> +#define INTELVIPFB_FRAME_COUNTER       0xC
> +#define INTELVIPFB_FRAME_DROP          0x10
> +#define INTELVIPFB_FRAME_INFO          0x14
> +#define INTELVIPFB_FRAME_START         0x18
> +#define INTELVIPFB_FRAME_READER                0x1C
> +
> +int intelvipfb_probe(struct device *dev, void __iomem *base);
> +int intelvipfb_remove(struct device *dev);
> +int intelvipfb_setup_crtc(struct drm_device *drm);
> +struct drm_connector *intelvipfb_conn_setup(struct drm_device *drm);
> +
> +struct intelvipfb_priv {
> +	struct drm_simple_display_pipe pipe;
> +	struct drm_fbdev_cma *fbcma;
> +	struct drm_device *drm;
> +	void    __iomem *base;
> +};
> +
> +#endif
> diff --git a/drivers/gpu/drm/ivip/intel_vip_of.c
> b/drivers/gpu/drm/ivip/intel_vip_of.c new file mode 100644
> index 0000000..5a7c63b
> --- /dev/null
> +++ b/drivers/gpu/drm/ivip/intel_vip_of.c
> @@ -0,0 +1,204 @@
> +/*
> + * intel_vip_of.c -- Intel Video and Image Processing(VIP)
> + * Frame Buffer II driver
> + *
> + * This driver supports the Intel VIP Frame Reader component.
> + * More info on the hardware can be found in the Intel Video
> + * and Image Processing Suite User Guide at this address
> + * http://www.altera.com/literature/ug/ug_vip.pdf.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> for
> + * more details.
> + *
> + * Authors:
> + * Ong, Hean-Loong <hean.loong.ong@xxxxxxxxx>
> + *
> + */
> +
> +#include <linux/component.h>
> +#include <linux/fb.h>

I don't think those two headers are needed.

> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_fb_cma_helper.h>
> +#include <drm/drm_gem_cma_helper.h>
> +#include <drm/drm_simple_kms_helper.h>

Please sort these alphabetically.

> +
> +#include "intel_vip_drv.h"
> +
> +DEFINE_DRM_GEM_CMA_FOPS(drm_fops);
> +
> +static void intelvipfb_lastclose(struct drm_device *drm)
> +{
> +	struct intelvipfb_priv *priv = drm->dev_private;
> +
> +	drm_fbdev_cma_restore_mode(priv->fbcma);
> +}
> +
> +static struct drm_driver intelvipfb_drm = {
> +	.driver_features =
> +		DRIVER_MODESET | DRIVER_GEM |
> +		DRIVER_PRIME | DRIVER_ATOMIC,
> +	.gem_free_object_unlocked = drm_gem_cma_free_object,
> +	.gem_vm_ops = &drm_gem_cma_vm_ops,
> +	.dumb_create = drm_gem_cma_dumb_create,
> +	.dumb_map_offset = drm_gem_cma_dumb_map_offset,
> +	.dumb_destroy = drm_gem_dumb_destroy,
> +	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
> +	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> +	.gem_prime_export = drm_gem_prime_export,
> +	.gem_prime_import = drm_gem_prime_import,
> +	.gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
> +	.gem_prime_import_sg_table = drm_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,
> +	.lastclose = intelvipfb_lastclose,
> +	.name = DRIVER_NAME,
> +	.date = "20170729",
> +	.desc = "Intel FPGA VIP SUITE",
> +	.major = 1,
> +	.minor = 0,
> +	.ioctls = NULL,
> +	.patchlevel = 0,
> +	.fops = &drm_fops,
> +};
> +
> +/*
> + * Setting up information derived from OF Device Tree Nodes
> + * max-width, max-height, bits per pixel, memory port width
> + */
> +
> +static int intelvipfb_drm_setup(struct device *dev,
> +			struct intelvipfb_priv *fbpriv)
> +{
> +	struct drm_device *drm = fbpriv->drm;
> +	struct device_node *np = dev->of_node;
> +	int mem_word_width;
> +	int max_h, max_w;
> +	int bpp;
> +	int ret;
> +
> +	ret = of_property_read_u32(np, "altr,max-width", &max_w);
> +	if (ret) {
> +		dev_err(dev,
> +		"Missing required parameter 'altr,max-width'");
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(np, "altr,max-height", &max_h);
> +	if (ret) {
> +		dev_err(dev,
> +		"Missing required parameter 'altr,max-height'");
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(np, "altr,bits-per-symbol", &bpp);

This property is not documented in patch 1/3.

> +	if (ret) {
> +		dev_err(dev,
> +		"Missing required parameter 'altr,bits-per-symbol'");
> +		return ret;
> +	}
> +
> +	ret = of_property_read_u32(np, "altr,mem-port-width", 
&mem_word_width);
> +	if (ret) {
> +		dev_err(dev, "Missing required parameter 'altr,mem-port-width 
'");
> +		return ret;
> +	}
> +
> +	if (!(mem_word_width >= 32 && mem_word_width % 32 == 0)) {
> +		dev_err(dev,
> +		"mem-word-width is set to %i. must be >= 32 and multiple of 
32.",
> +		mem_word_width);
> +		return -ENODEV;
> +	}
> +
> +	drm->mode_config.min_width = 640;
> +	drm->mode_config.min_height = 480;
> +	drm->mode_config.max_width = max_w;
> +	drm->mode_config.max_height = max_h;
> +	drm->mode_config.preferred_depth = bpp * BYTES_PER_PIXEL;
> +
> +	return 0;
> +}

-- 
Regards,

Laurent Pinchart