diff mbox

[v2,07/12] drm/sun4i: Add a driver for the display frontend

Message ID 78c17058b8a38a4e38005aec451dd22e9a329e05.1513609024.git-series.maxime.ripard@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Maxime Ripard Dec. 18, 2017, 2:57 p.m. UTC
The display frontend is an hardware block that can be used to implement
some more advanced features like hardware scaling or colorspace
conversions. It can also be used to implement the output format of the VPU.

Let's create a minimal driver for it that will only enable the hardware
scaling features.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/Makefile         |   3 +-
 drivers/gpu/drm/sun4i/sun4i_drv.c      |  16 +-
 drivers/gpu/drm/sun4i/sun4i_drv.h      |   1 +-
 drivers/gpu/drm/sun4i/sun4i_frontend.c | 392 ++++++++++++++++++++++++++-
 drivers/gpu/drm/sun4i/sun4i_frontend.h |  96 ++++++-
 5 files changed, 503 insertions(+), 5 deletions(-)
 create mode 100644 drivers/gpu/drm/sun4i/sun4i_frontend.c
 create mode 100644 drivers/gpu/drm/sun4i/sun4i_frontend.h

Comments

Chen-Yu Tsai Jan. 4, 2018, 3:35 p.m. UTC | #1
On Mon, Dec 18, 2017 at 10:57 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> The display frontend is an hardware block that can be used to implement
> some more advanced features like hardware scaling or colorspace
> conversions. It can also be used to implement the output format of the VPU.
>
> Let's create a minimal driver for it that will only enable the hardware
> scaling features.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/Makefile         |   3 +-
>  drivers/gpu/drm/sun4i/sun4i_drv.c      |  16 +-
>  drivers/gpu/drm/sun4i/sun4i_drv.h      |   1 +-
>  drivers/gpu/drm/sun4i/sun4i_frontend.c | 392 ++++++++++++++++++++++++++-
>  drivers/gpu/drm/sun4i/sun4i_frontend.h |  96 ++++++-
>  5 files changed, 503 insertions(+), 5 deletions(-)
>  create mode 100644 drivers/gpu/drm/sun4i/sun4i_frontend.c
>  create mode 100644 drivers/gpu/drm/sun4i/sun4i_frontend.h
>
> diff --git a/drivers/gpu/drm/sun4i/Makefile b/drivers/gpu/drm/sun4i/Makefile
> index 0c2f8c7facae..b660d82011f4 100644
> --- a/drivers/gpu/drm/sun4i/Makefile
> +++ b/drivers/gpu/drm/sun4i/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  sun4i-backend-y                        += sun4i_backend.o sun4i_layer.o
> +sun4i-frontend-y               += sun4i_frontend.o
>
>  sun4i-drm-y                    += sun4i_drv.o
>  sun4i-drm-y                    += sun4i_framebuffer.o
> @@ -21,6 +22,6 @@ obj-$(CONFIG_DRM_SUN4I)               += sun4i-tcon.o
>  obj-$(CONFIG_DRM_SUN4I)                += sun4i_tv.o
>  obj-$(CONFIG_DRM_SUN4I)                += sun6i_drc.o
>
> -obj-$(CONFIG_DRM_SUN4I_BACKEND)        += sun4i-backend.o
> +obj-$(CONFIG_DRM_SUN4I_BACKEND)        += sun4i-backend.o sun4i-frontend.o
>  obj-$(CONFIG_DRM_SUN4I_HDMI)   += sun4i-drm-hdmi.o
>  obj-$(CONFIG_DRM_SUN8I_MIXER)  += sun8i-mixer.o
> diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
> index 75c76cdd82bc..17bf9bfd98ba 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_drv.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
> @@ -98,6 +98,7 @@ static int sun4i_drv_bind(struct device *dev)
>                 goto free_drm;
>         }
>         drm->dev_private = drv;
> +       INIT_LIST_HEAD(&drv->frontend_list);
>         INIT_LIST_HEAD(&drv->engine_list);
>         INIT_LIST_HEAD(&drv->tcon_list);
>
> @@ -239,9 +240,11 @@ static int sun4i_drv_add_endpoints(struct device *dev,
>         int count = 0;
>
>         /*
> -        * We don't support the frontend for now, so we will never
> -        * have a device bound. Just skip over it, but we still want
> -        * the rest our pipeline to be added.
> +        * The frontend has been disabled in all of our old device

Not quite... I left them enabled in all the ones I did (A10/A20/A31)...

> +        * trees. If we find a node that is the frontend and is
> +        * disabled, we should just follow through and parse its
> +        * child, but without adding it to the component list.
> +        * Otherwise, we obviously want to add it to the list.
>          */
>         if (!sun4i_drv_node_is_frontend(node) &&
>             !of_device_is_available(node))
> @@ -254,7 +257,12 @@ static int sun4i_drv_add_endpoints(struct device *dev,
>         if (sun4i_drv_node_is_connector(node))
>                 return 0;
>
> -       if (!sun4i_drv_node_is_frontend(node)) {
> +       /*
> +        * If the device is either just a regular device, or an
> +        * enabled frontend, we add it to our component list.
> +        */
> +       if (!sun4i_drv_node_is_frontend(node) ||
> +           (sun4i_drv_node_is_frontend(node) && of_device_is_available(node))) {
>                 /* Add current component */
>                 DRM_DEBUG_DRIVER("Adding component %pOF\n", node);
>                 drm_of_component_match_add(dev, match, compare_of, node);
> diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.h b/drivers/gpu/drm/sun4i/sun4i_drv.h
> index a960c89270cc..9c26a345f85c 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_drv.h
> +++ b/drivers/gpu/drm/sun4i/sun4i_drv.h
> @@ -19,6 +19,7 @@
>
>  struct sun4i_drv {
>         struct list_head        engine_list;
> +       struct list_head        frontend_list;
>         struct list_head        tcon_list;
>
>         struct drm_fbdev_cma    *fbdev;
> diff --git a/drivers/gpu/drm/sun4i/sun4i_frontend.c b/drivers/gpu/drm/sun4i/sun4i_frontend.c
> new file mode 100644
> index 000000000000..fb3e96ab57f7
> --- /dev/null
> +++ b/drivers/gpu/drm/sun4i/sun4i_frontend.c
> @@ -0,0 +1,392 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2017 Free Electrons
> + * Maxime Ripard <maxime.ripard@free-electrons.com>
> + */
> +#include <drm/drmP.h>
> +#include <drm/drm_gem_cma_helper.h>
> +#include <drm/drm_fb_cma_helper.h>
> +
> +#include <linux/clk.h>
> +#include <linux/component.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +#include "sun4i_drv.h"
> +#include "sun4i_frontend.h"
> +
> +static const u32 sun4i_frontend_vert_coef[32] = {
> +       0x00004000, 0x000140ff, 0x00033ffe, 0x00043ffd,
> +       0x00063efc, 0xff083dfc, 0x000a3bfb, 0xff0d39fb,
> +       0xff0f37fb, 0xff1136fa, 0xfe1433fb, 0xfe1631fb,
> +       0xfd192ffb, 0xfd1c2cfb, 0xfd1f29fb, 0xfc2127fc,
> +       0xfc2424fc, 0xfc2721fc, 0xfb291ffd, 0xfb2c1cfd,
> +       0xfb2f19fd, 0xfb3116fe, 0xfb3314fe, 0xfa3611ff,
> +       0xfb370fff, 0xfb390dff, 0xfb3b0a00, 0xfc3d08ff,
> +       0xfc3e0600, 0xfd3f0400, 0xfe3f0300, 0xff400100,
> +};
> +
> +static const u32 sun4i_frontend_horz_coef[64] = {
> +       0x40000000, 0x00000000, 0x40fe0000, 0x0000ff03,
> +       0x3ffd0000, 0x0000ff05, 0x3ffc0000, 0x0000ff06,
> +       0x3efb0000, 0x0000ff08, 0x3dfb0000, 0x0000ff09,
> +       0x3bfa0000, 0x0000fe0d, 0x39fa0000, 0x0000fe0f,
> +       0x38fa0000, 0x0000fe10, 0x36fa0000, 0x0000fe12,
> +       0x33fa0000, 0x0000fd16, 0x31fa0000, 0x0000fd18,
> +       0x2ffa0000, 0x0000fd1a, 0x2cfa0000, 0x0000fc1e,
> +       0x29fa0000, 0x0000fc21, 0x27fb0000, 0x0000fb23,
> +       0x24fb0000, 0x0000fb26, 0x21fb0000, 0x0000fb29,
> +       0x1ffc0000, 0x0000fa2b, 0x1cfc0000, 0x0000fa2e,
> +       0x19fd0000, 0x0000fa30, 0x16fd0000, 0x0000fa33,
> +       0x14fd0000, 0x0000fa35, 0x11fe0000, 0x0000fa37,
> +       0x0ffe0000, 0x0000fa39, 0x0dfe0000, 0x0000fa3b,
> +       0x0afe0000, 0x0000fa3e, 0x08ff0000, 0x0000fb3e,
> +       0x06ff0000, 0x0000fb40, 0x05ff0000, 0x0000fc40,
> +       0x03ff0000, 0x0000fd41, 0x01ff0000, 0x0000fe42,
> +};
> +
> +static void sun4i_frontend_scaler_init(struct sun4i_frontend *frontend)
> +{
> +       int i;
> +
> +       for (i = 0; i < 32; i++) {
> +               regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZCOEF0_REG(i),
> +                            sun4i_frontend_horz_coef[2 * i]);
> +               regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZCOEF0_REG(i),
> +                            sun4i_frontend_horz_coef[2 * i]);
> +               regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZCOEF1_REG(i),
> +                            sun4i_frontend_horz_coef[2 * i + 1]);
> +               regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZCOEF1_REG(i),
> +                            sun4i_frontend_horz_coef[2 * i + 1]);
> +               regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTCOEF_REG(i),
> +                            sun4i_frontend_vert_coef[i]);
> +               regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTCOEF_REG(i),
> +                            sun4i_frontend_vert_coef[i]);
> +       }
> +
> +       regmap_update_bits(frontend->regs, SUN4I_FRONTEND_FRM_CTRL_REG, BIT(23), BIT(23));
> +}
> +
> +int sun4i_frontend_init(struct sun4i_frontend *frontend)
> +{
> +       return pm_runtime_get_sync(frontend->dev);
> +}
> +EXPORT_SYMBOL(sun4i_frontend_init);
> +
> +void sun4i_frontend_exit(struct sun4i_frontend *frontend)
> +{
> +       pm_runtime_put(frontend->dev);
> +}
> +EXPORT_SYMBOL(sun4i_frontend_exit);
> +
> +void sun4i_frontend_update_buffer(struct sun4i_frontend *frontend,
> +                                 struct drm_plane *plane)
> +{
> +       struct drm_plane_state *state = plane->state;
> +       struct drm_framebuffer *fb = state->fb;
> +       struct drm_gem_cma_object *gem;
> +       dma_addr_t paddr;
> +       int bpp;
> +
> +       /* Get the physical address of the buffer in memory */
> +       gem = drm_fb_cma_get_gem_obj(fb, 0);
> +
> +       DRM_DEBUG_DRIVER("Using GEM @ %pad\n", &gem->paddr);
> +
> +       /* Set the line width */
> +       DRM_DEBUG_DRIVER("Frontend stride: %d bytes\n", fb->pitches[0]);
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_LINESTRD0_REG,
> +                    fb->pitches[0]);
> +
> +       /* Compute the start of the displayed memory */
> +       bpp = fb->format->cpp[0];
> +       paddr = gem->paddr + fb->offsets[0];
> +       paddr += (state->src_x >> 16) * bpp;
> +       paddr += (state->src_y >> 16) * fb->pitches[0];

You can use drm_fb_cma_get_gem_addr(fb, state, 0), instead of open
coding it.

Do we need to convert the address, like with the backend?

> +
> +       DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_BUF_ADDR0_REG, paddr);
> +}
> +EXPORT_SYMBOL(sun4i_frontend_update_buffer);
> +
> +static int sun4i_frontend_drm_format_to_input_fmt(uint32_t fmt, u32 *val)
> +{
> +       switch (fmt) {
> +       case DRM_FORMAT_ARGB8888:
> +       case DRM_FORMAT_XRGB8888:
> +               *val = 3;
> +               return 0;
> +
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +static int sun4i_frontend_drm_format_to_output_fmt(uint32_t fmt, u32 *val)
> +{
> +       switch (fmt) {
> +       case DRM_FORMAT_ARGB8888:
> +               *val = 2;
> +               return 0;
> +
> +       default:
> +               return -EINVAL;
> +       }
> +}
> +
> +int sun4i_frontend_update_formats(struct sun4i_frontend *frontend,
> +                                 struct drm_plane *plane, uint32_t out_fmt)
> +{
> +       struct drm_plane_state *state = plane->state;
> +       struct drm_framebuffer *fb = state->fb;
> +       u32 out_fmt_val;
> +       u32 in_fmt_val;
> +       int ret;
> +
> +       ret = sun4i_frontend_drm_format_to_input_fmt(fb->format->format,
> +                                                    &in_fmt_val);
> +       if (ret) {
> +               DRM_DEBUG_DRIVER("Invalid input format\n");
> +               return ret;
> +       }
> +
> +       ret = sun4i_frontend_drm_format_to_output_fmt(out_fmt, &out_fmt_val);
> +       if (ret) {
> +               DRM_DEBUG_DRIVER("Invalid output format\n");
> +               return ret;
> +       }
> +
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZPHASE_REG, 0x400);
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZPHASE_REG, 0x400);
> +
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTPHASE0_REG, 0x400);
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTPHASE0_REG, 0x400);
> +
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTPHASE1_REG, 0x400);
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTPHASE1_REG, 0x400);

I really don't understand any of this. :(

> +
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_INPUT_FMT_REG,
> +                    SUN4I_FRONTEND_INPUT_FMT_DATA_MOD(1) |
> +                    SUN4I_FRONTEND_INPUT_FMT_DATA_FMT(5) |
> +                    SUN4I_FRONTEND_INPUT_FMT_PS(1));
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_OUTPUT_FMT_REG,
> +                    SUN4I_FRONTEND_OUTPUT_FMT_DATA_FMT(1));

You don't seem to be using the values you got from the helper functions.
Moreover, they don't match the values you claim to support.

> +
> +       return 0;
> +}
> +EXPORT_SYMBOL(sun4i_frontend_update_formats);
> +
> +void sun4i_frontend_update_coord(struct sun4i_frontend *frontend,
> +                                struct drm_plane *plane)
> +{
> +       struct drm_plane_state *state = plane->state;
> +
> +       /* Set height and width */
> +       DRM_DEBUG_DRIVER("Frontend size W: %u H: %u\n",
> +                        state->crtc_w, state->crtc_h);
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_INSIZE_REG,
> +                    SUN4I_FRONTEND_INSIZE(state->src_h >> 16,
> +                                          state->src_w >> 16));
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_INSIZE_REG,
> +                    SUN4I_FRONTEND_INSIZE(state->src_h >> 16,
> +                                          state->src_w >> 16));

Slighty off-topic, but does the kernel provide helpers for 16.16
fixed point arithmetic?

> +
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_OUTSIZE_REG,
> +                    SUN4I_FRONTEND_OUTSIZE(state->crtc_h, state->crtc_w));
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_OUTSIZE_REG,
> +                    SUN4I_FRONTEND_OUTSIZE(state->crtc_h, state->crtc_w));

Do you need to set the line stride registers?

> +
> +       DRM_DEBUG_DRIVER("Frontend horizontal scaling factor %d.%d\n", 1, 0);

Value doesn't match what is programmed.

> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZFACT_REG,
> +                    state->src_w / state->crtc_w);
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZFACT_REG,
> +                    state->src_w / state->crtc_w);
> +
> +       DRM_DEBUG_DRIVER("Frontend vertical scaling factor %d.%d\n", 1, 0);

Neither does this.

> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTFACT_REG,
> +                    state->src_h / state->crtc_h);
> +       regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTFACT_REG,
> +                    state->src_h / state->crtc_h);

I don't think you need to program any of the channel 1 registers for
interleaved data.

> +
> +       regmap_write_bits(frontend->regs, SUN4I_FRONTEND_FRM_CTRL_REG,
> +                         SUN4I_FRONTEND_FRM_CTRL_REG_RDY,
> +                         SUN4I_FRONTEND_FRM_CTRL_REG_RDY);
> +}
> +EXPORT_SYMBOL(sun4i_frontend_update_coord);
> +
> +int sun4i_frontend_enable(struct sun4i_frontend *frontend)
> +{
> +       regmap_write_bits(frontend->regs, SUN4I_FRONTEND_FRM_CTRL_REG,
> +                         SUN4I_FRONTEND_FRM_CTRL_FRM_START,
> +                         SUN4I_FRONTEND_FRM_CTRL_FRM_START);
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL(sun4i_frontend_enable);
> +
> +static struct regmap_config sun4i_frontend_regmap_config = {
> +       .reg_bits       = 32,
> +       .val_bits       = 32,
> +       .reg_stride     = 4,
> +       .max_register   = 0x0a14,
> +};
> +
> +static int sun4i_frontend_bind(struct device *dev, struct device *master,
> +                        void *data)
> +{
> +       struct platform_device *pdev = to_platform_device(dev);
> +       struct sun4i_frontend *frontend;
> +       struct drm_device *drm = data;
> +       struct sun4i_drv *drv = drm->dev_private;
> +       struct resource *res;
> +       void __iomem *regs;
> +
> +       frontend = devm_kzalloc(dev, sizeof(*frontend), GFP_KERNEL);
> +       if (!frontend)
> +               return -ENOMEM;
> +
> +       dev_set_drvdata(dev, frontend);
> +       frontend->dev = dev;
> +       frontend->node = dev->of_node;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       regs = devm_ioremap_resource(dev, res);
> +       if (IS_ERR(regs))
> +               return PTR_ERR(regs);
> +
> +       frontend->regs = devm_regmap_init_mmio(dev, regs,
> +                                              &sun4i_frontend_regmap_config);
> +       if (IS_ERR(frontend->regs)) {
> +               dev_err(dev, "Couldn't create the frontend regmap\n");
> +               return PTR_ERR(frontend->regs);
> +       }
> +
> +       frontend->reset = devm_reset_control_get(dev, NULL);
> +       if (IS_ERR(frontend->reset)) {
> +               dev_err(dev, "Couldn't get our reset line\n");
> +               return PTR_ERR(frontend->reset);
> +       }
> +
> +       frontend->bus_clk = devm_clk_get(dev, "ahb");
> +       if (IS_ERR(frontend->bus_clk)) {
> +               dev_err(dev, "Couldn't get our bus clock\n");
> +               return PTR_ERR(frontend->bus_clk);
> +       }
> +
> +       frontend->mod_clk = devm_clk_get(dev, "mod");
> +       if (IS_ERR(frontend->mod_clk)) {
> +               dev_err(dev, "Couldn't get our mod clock\n");
> +               return PTR_ERR(frontend->mod_clk);
> +       }
> +
> +       frontend->ram_clk = devm_clk_get(dev, "ram");
> +       if (IS_ERR(frontend->ram_clk)) {
> +               dev_err(dev, "Couldn't get our ram clock\n");
> +               return PTR_ERR(frontend->ram_clk);
> +       }
> +
> +       list_add_tail(&frontend->list, &drv->frontend_list);

Maybe force a reset here?

> +       pm_runtime_enable(dev);
> +
> +       return 0;
> +}
> +
> +static void sun4i_frontend_unbind(struct device *dev, struct device *master,
> +                           void *data)
> +{
> +       struct sun4i_frontend *frontend = dev_get_drvdata(dev);
> +
> +       list_del(&frontend->list);
> +       pm_runtime_force_suspend(dev);
> +}
> +
> +static const struct component_ops sun4i_frontend_ops = {
> +       .bind   = sun4i_frontend_bind,
> +       .unbind = sun4i_frontend_unbind,
> +};
> +
> +static int sun4i_frontend_probe(struct platform_device *pdev)
> +{
> +       return component_add(&pdev->dev, &sun4i_frontend_ops);
> +}
> +
> +static int sun4i_frontend_remove(struct platform_device *pdev)
> +{
> +       component_del(&pdev->dev, &sun4i_frontend_ops);
> +
> +       return 0;
> +}
> +
> +static int sun4i_frontend_runtime_resume(struct device *dev)
> +{
> +       struct sun4i_frontend *frontend = dev_get_drvdata(dev);
> +       int ret;
> +
> +       ret = reset_control_deassert(frontend->reset);
> +       if (ret) {
> +               dev_err(dev, "Couldn't deassert our reset line\n");
> +               return ret;
> +       }
> +
> +       clk_set_rate(frontend->mod_clk, 300000000);
> +
> +       clk_prepare_enable(frontend->bus_clk);
> +       clk_prepare_enable(frontend->mod_clk);
> +       clk_prepare_enable(frontend->ram_clk);

I wonder if the clocks should be enabled first, so the registers
and internal state gets properly reset?

> +
> +       regmap_update_bits(frontend->regs, SUN4I_FRONTEND_EN_REG,
> +                          SUN4I_FRONTEND_EN_EN,
> +                          SUN4I_FRONTEND_EN_EN);
> +

You also need to set OUT_PORT_SEL in FRM_CTRL_REG so that frontend1
correctly outputs to backend1, assuming a static mapping.

> +       regmap_update_bits(frontend->regs, SUN4I_FRONTEND_BYPASS_REG,
> +                          SUN4I_FRONTEND_BYPASS_CSC_EN,
> +                          SUN4I_FRONTEND_BYPASS_CSC_EN);
> +
> +       sun4i_frontend_scaler_init(frontend);
> +
> +       return 0;
> +}
> +
> +static int sun4i_frontend_runtime_suspend(struct device *dev)
> +{
> +       struct sun4i_frontend *frontend = dev_get_drvdata(dev);
> +
> +       clk_disable_unprepare(frontend->ram_clk);
> +       clk_disable_unprepare(frontend->mod_clk);
> +       clk_disable_unprepare(frontend->bus_clk);
> +
> +       reset_control_assert(frontend->reset);
> +
> +       return 0;
> +}
> +
> +static const struct dev_pm_ops sun4i_frontend_pm_ops = {
> +       .runtime_resume         = sun4i_frontend_runtime_resume,
> +       .runtime_suspend        = sun4i_frontend_runtime_suspend,
> +};
> +
> +static const struct of_device_id sun4i_frontend_of_table[] = {
> +       { .compatible = "allwinner,sun5i-a13-display-frontend" },
> +       { .compatible = "allwinner,sun6i-a31-display-frontend" },

What about A10 and A20?

Regards
ChenYu

> +       { .compatible = "allwinner,sun8i-a33-display-frontend" },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(of, sun4i_frontend_of_table);
> +
> +static struct platform_driver sun4i_frontend_driver = {
> +       .probe          = sun4i_frontend_probe,
> +       .remove         = sun4i_frontend_remove,
> +       .driver         = {
> +               .name           = "sun4i-frontend",
> +               .of_match_table = sun4i_frontend_of_table,
> +               .pm             = &sun4i_frontend_pm_ops,
> +       },
> +};
> +module_platform_driver(sun4i_frontend_driver);
> +
> +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
> +MODULE_DESCRIPTION("Allwinner A10 Display Engine Frontend Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/sun4i/sun4i_frontend.h b/drivers/gpu/drm/sun4i/sun4i_frontend.h
> new file mode 100644
> index 000000000000..5adc2c7266bc
> --- /dev/null
> +++ b/drivers/gpu/drm/sun4i/sun4i_frontend.h
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2017 Free Electrons
> + * Maxime Ripard <maxime.ripard@free-electrons.com>
> + */
> +
> +#ifndef _SUN4I_FRONTEND_H_
> +#define _SUN4I_FRONTEND_H_
> +
> +#include <linux/list.h>
> +
> +#define SUN4I_FRONTEND_EN_REG                  0x000
> +#define SUN4I_FRONTEND_EN_EN                           BIT(0)
> +
> +#define SUN4I_FRONTEND_FRM_CTRL_REG            0x004
> +#define SUN4I_FRONTEND_FRM_CTRL_FRM_START              BIT(16)
> +#define SUN4I_FRONTEND_FRM_CTRL_COEF_RDY               BIT(1)
> +#define SUN4I_FRONTEND_FRM_CTRL_REG_RDY                        BIT(0)
> +
> +#define SUN4I_FRONTEND_BYPASS_REG              0x008
> +#define SUN4I_FRONTEND_BYPASS_CSC_EN                   BIT(1)
> +
> +#define SUN4I_FRONTEND_BUF_ADDR0_REG           0x020
> +
> +#define SUN4I_FRONTEND_LINESTRD0_REG           0x040
> +
> +#define SUN4I_FRONTEND_INPUT_FMT_REG           0x04c
> +#define SUN4I_FRONTEND_INPUT_FMT_DATA_MOD(mod)         ((mod) << 8)
> +#define SUN4I_FRONTEND_INPUT_FMT_DATA_FMT(fmt)         ((fmt) << 4)
> +#define SUN4I_FRONTEND_INPUT_FMT_PS(ps)                        (ps)
> +
> +#define SUN4I_FRONTEND_OUTPUT_FMT_REG          0x05c
> +#define SUN4I_FRONTEND_OUTPUT_FMT_DATA_FMT(fmt)                (fmt)
> +
> +#define SUN4I_FRONTEND_CH0_INSIZE_REG          0x100
> +#define SUN4I_FRONTEND_INSIZE(h, w)                    ((((h) - 1) << 16) | (((w) - 1)))
> +
> +#define SUN4I_FRONTEND_CH0_OUTSIZE_REG         0x104
> +#define SUN4I_FRONTEND_OUTSIZE(h, w)                   ((((h) - 1) << 16) | (((w) - 1)))
> +
> +#define SUN4I_FRONTEND_CH0_HORZFACT_REG                0x108
> +#define SUN4I_FRONTEND_HORZFACT(i, f)                  (((i) << 16) | (f))
> +
> +#define SUN4I_FRONTEND_CH0_VERTFACT_REG                0x10c
> +#define SUN4I_FRONTEND_VERTFACT(i, f)                  (((i) << 16) | (f))
> +
> +#define SUN4I_FRONTEND_CH0_HORZPHASE_REG       0x110
> +#define SUN4I_FRONTEND_CH0_VERTPHASE0_REG      0x114
> +#define SUN4I_FRONTEND_CH0_VERTPHASE1_REG      0x118
> +
> +#define SUN4I_FRONTEND_CH1_INSIZE_REG          0x200
> +#define SUN4I_FRONTEND_CH1_OUTSIZE_REG         0x204
> +#define SUN4I_FRONTEND_CH1_HORZFACT_REG                0x208
> +#define SUN4I_FRONTEND_CH1_VERTFACT_REG                0x20c
> +
> +#define SUN4I_FRONTEND_CH1_HORZPHASE_REG       0x210
> +#define SUN4I_FRONTEND_CH1_VERTPHASE0_REG      0x214
> +#define SUN4I_FRONTEND_CH1_VERTPHASE1_REG      0x218
> +
> +#define SUN4I_FRONTEND_CH0_HORZCOEF0_REG(i)    (0x400 + i * 4)
> +#define SUN4I_FRONTEND_CH0_HORZCOEF1_REG(i)    (0x480 + i * 4)
> +#define SUN4I_FRONTEND_CH0_VERTCOEF_REG(i)     (0x500 + i * 4)
> +#define SUN4I_FRONTEND_CH1_HORZCOEF0_REG(i)    (0x600 + i * 4)
> +#define SUN4I_FRONTEND_CH1_HORZCOEF1_REG(i)    (0x680 + i * 4)
> +#define SUN4I_FRONTEND_CH1_VERTCOEF_REG(i)     (0x700 + i * 4)
> +
> +struct clk;
> +struct device_node;
> +struct drm_plane;
> +struct regmap;
> +struct reset_control;
> +
> +struct sun4i_frontend {
> +       struct list_head        list;
> +       struct device           *dev;
> +       struct device_node      *node;
> +
> +       struct clk              *bus_clk;
> +       struct clk              *mod_clk;
> +       struct clk              *ram_clk;
> +       struct regmap           *regs;
> +       struct reset_control    *reset;
> +};
> +
> +int sun4i_frontend_init(struct sun4i_frontend *frontend);
> +void sun4i_frontend_exit(struct sun4i_frontend *frontend);
> +int sun4i_frontend_enable(struct sun4i_frontend *frontend);
> +
> +void sun4i_frontend_update_buffer(struct sun4i_frontend *frontend,
> +                                 struct drm_plane *plane);
> +void sun4i_frontend_update_coord(struct sun4i_frontend *frontend,
> +                                struct drm_plane *plane);
> +int sun4i_frontend_update_formats(struct sun4i_frontend *frontend,
> +                                 struct drm_plane *plane, uint32_t out_fmt);
> +
> +#endif /* _SUN4I_FRONTEND_H_ */
> --
> git-series 0.9.1
diff mbox

Patch

diff --git a/drivers/gpu/drm/sun4i/Makefile b/drivers/gpu/drm/sun4i/Makefile
index 0c2f8c7facae..b660d82011f4 100644
--- a/drivers/gpu/drm/sun4i/Makefile
+++ b/drivers/gpu/drm/sun4i/Makefile
@@ -1,5 +1,6 @@ 
 # SPDX-License-Identifier: GPL-2.0
 sun4i-backend-y			+= sun4i_backend.o sun4i_layer.o
+sun4i-frontend-y		+= sun4i_frontend.o
 
 sun4i-drm-y			+= sun4i_drv.o
 sun4i-drm-y			+= sun4i_framebuffer.o
@@ -21,6 +22,6 @@  obj-$(CONFIG_DRM_SUN4I)		+= sun4i-tcon.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i_tv.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun6i_drc.o
 
-obj-$(CONFIG_DRM_SUN4I_BACKEND)	+= sun4i-backend.o
+obj-$(CONFIG_DRM_SUN4I_BACKEND)	+= sun4i-backend.o sun4i-frontend.o
 obj-$(CONFIG_DRM_SUN4I_HDMI)	+= sun4i-drm-hdmi.o
 obj-$(CONFIG_DRM_SUN8I_MIXER)	+= sun8i-mixer.o
diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 75c76cdd82bc..17bf9bfd98ba 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -98,6 +98,7 @@  static int sun4i_drv_bind(struct device *dev)
 		goto free_drm;
 	}
 	drm->dev_private = drv;
+	INIT_LIST_HEAD(&drv->frontend_list);
 	INIT_LIST_HEAD(&drv->engine_list);
 	INIT_LIST_HEAD(&drv->tcon_list);
 
@@ -239,9 +240,11 @@  static int sun4i_drv_add_endpoints(struct device *dev,
 	int count = 0;
 
 	/*
-	 * We don't support the frontend for now, so we will never
-	 * have a device bound. Just skip over it, but we still want
-	 * the rest our pipeline to be added.
+	 * The frontend has been disabled in all of our old device
+	 * trees. If we find a node that is the frontend and is
+	 * disabled, we should just follow through and parse its
+	 * child, but without adding it to the component list.
+	 * Otherwise, we obviously want to add it to the list.
 	 */
 	if (!sun4i_drv_node_is_frontend(node) &&
 	    !of_device_is_available(node))
@@ -254,7 +257,12 @@  static int sun4i_drv_add_endpoints(struct device *dev,
 	if (sun4i_drv_node_is_connector(node))
 		return 0;
 
-	if (!sun4i_drv_node_is_frontend(node)) {
+	/*
+	 * If the device is either just a regular device, or an
+	 * enabled frontend, we add it to our component list.
+	 */
+	if (!sun4i_drv_node_is_frontend(node) ||
+	    (sun4i_drv_node_is_frontend(node) && of_device_is_available(node))) {
 		/* Add current component */
 		DRM_DEBUG_DRIVER("Adding component %pOF\n", node);
 		drm_of_component_match_add(dev, match, compare_of, node);
diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.h b/drivers/gpu/drm/sun4i/sun4i_drv.h
index a960c89270cc..9c26a345f85c 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.h
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.h
@@ -19,6 +19,7 @@ 
 
 struct sun4i_drv {
 	struct list_head	engine_list;
+	struct list_head	frontend_list;
 	struct list_head	tcon_list;
 
 	struct drm_fbdev_cma	*fbdev;
diff --git a/drivers/gpu/drm/sun4i/sun4i_frontend.c b/drivers/gpu/drm/sun4i/sun4i_frontend.c
new file mode 100644
index 000000000000..fb3e96ab57f7
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun4i_frontend.c
@@ -0,0 +1,392 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017 Free Electrons
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+#include <drm/drmP.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include "sun4i_drv.h"
+#include "sun4i_frontend.h"
+
+static const u32 sun4i_frontend_vert_coef[32] = {
+	0x00004000, 0x000140ff, 0x00033ffe, 0x00043ffd,
+	0x00063efc, 0xff083dfc, 0x000a3bfb, 0xff0d39fb,
+	0xff0f37fb, 0xff1136fa, 0xfe1433fb, 0xfe1631fb,
+	0xfd192ffb, 0xfd1c2cfb, 0xfd1f29fb, 0xfc2127fc,
+	0xfc2424fc, 0xfc2721fc, 0xfb291ffd, 0xfb2c1cfd,
+	0xfb2f19fd, 0xfb3116fe, 0xfb3314fe, 0xfa3611ff,
+	0xfb370fff, 0xfb390dff, 0xfb3b0a00, 0xfc3d08ff,
+	0xfc3e0600, 0xfd3f0400, 0xfe3f0300, 0xff400100,
+};
+
+static const u32 sun4i_frontend_horz_coef[64] = {
+	0x40000000, 0x00000000, 0x40fe0000, 0x0000ff03,
+	0x3ffd0000, 0x0000ff05, 0x3ffc0000, 0x0000ff06,
+	0x3efb0000, 0x0000ff08, 0x3dfb0000, 0x0000ff09,
+	0x3bfa0000, 0x0000fe0d, 0x39fa0000, 0x0000fe0f,
+	0x38fa0000, 0x0000fe10, 0x36fa0000, 0x0000fe12,
+	0x33fa0000, 0x0000fd16, 0x31fa0000, 0x0000fd18,
+	0x2ffa0000, 0x0000fd1a, 0x2cfa0000, 0x0000fc1e,
+	0x29fa0000, 0x0000fc21, 0x27fb0000, 0x0000fb23,
+	0x24fb0000, 0x0000fb26, 0x21fb0000, 0x0000fb29,
+	0x1ffc0000, 0x0000fa2b, 0x1cfc0000, 0x0000fa2e,
+	0x19fd0000, 0x0000fa30, 0x16fd0000, 0x0000fa33,
+	0x14fd0000, 0x0000fa35, 0x11fe0000, 0x0000fa37,
+	0x0ffe0000, 0x0000fa39, 0x0dfe0000, 0x0000fa3b,
+	0x0afe0000, 0x0000fa3e, 0x08ff0000, 0x0000fb3e,
+	0x06ff0000, 0x0000fb40, 0x05ff0000, 0x0000fc40,
+	0x03ff0000, 0x0000fd41, 0x01ff0000, 0x0000fe42,
+};
+
+static void sun4i_frontend_scaler_init(struct sun4i_frontend *frontend)
+{
+	int i;
+
+	for (i = 0; i < 32; i++) {
+		regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZCOEF0_REG(i),
+			     sun4i_frontend_horz_coef[2 * i]);
+		regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZCOEF0_REG(i),
+			     sun4i_frontend_horz_coef[2 * i]);
+		regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZCOEF1_REG(i),
+			     sun4i_frontend_horz_coef[2 * i + 1]);
+		regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZCOEF1_REG(i),
+			     sun4i_frontend_horz_coef[2 * i + 1]);
+		regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTCOEF_REG(i),
+			     sun4i_frontend_vert_coef[i]);
+		regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTCOEF_REG(i),
+			     sun4i_frontend_vert_coef[i]);
+	}
+
+	regmap_update_bits(frontend->regs, SUN4I_FRONTEND_FRM_CTRL_REG, BIT(23), BIT(23));
+}
+
+int sun4i_frontend_init(struct sun4i_frontend *frontend)
+{
+	return pm_runtime_get_sync(frontend->dev);
+}
+EXPORT_SYMBOL(sun4i_frontend_init);
+
+void sun4i_frontend_exit(struct sun4i_frontend *frontend)
+{
+	pm_runtime_put(frontend->dev);
+}
+EXPORT_SYMBOL(sun4i_frontend_exit);
+
+void sun4i_frontend_update_buffer(struct sun4i_frontend *frontend,
+				  struct drm_plane *plane)
+{
+	struct drm_plane_state *state = plane->state;
+	struct drm_framebuffer *fb = state->fb;
+	struct drm_gem_cma_object *gem;
+	dma_addr_t paddr;
+	int bpp;
+
+	/* Get the physical address of the buffer in memory */
+	gem = drm_fb_cma_get_gem_obj(fb, 0);
+
+	DRM_DEBUG_DRIVER("Using GEM @ %pad\n", &gem->paddr);
+
+	/* Set the line width */
+	DRM_DEBUG_DRIVER("Frontend stride: %d bytes\n", fb->pitches[0]);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_LINESTRD0_REG,
+		     fb->pitches[0]);
+
+	/* Compute the start of the displayed memory */
+	bpp = fb->format->cpp[0];
+	paddr = gem->paddr + fb->offsets[0];
+	paddr += (state->src_x >> 16) * bpp;
+	paddr += (state->src_y >> 16) * fb->pitches[0];
+
+	DRM_DEBUG_DRIVER("Setting buffer address to %pad\n", &paddr);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_BUF_ADDR0_REG, paddr);
+}
+EXPORT_SYMBOL(sun4i_frontend_update_buffer);
+
+static int sun4i_frontend_drm_format_to_input_fmt(uint32_t fmt, u32 *val)
+{
+	switch (fmt) {
+	case DRM_FORMAT_ARGB8888:
+	case DRM_FORMAT_XRGB8888:
+		*val = 3;
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int sun4i_frontend_drm_format_to_output_fmt(uint32_t fmt, u32 *val)
+{
+	switch (fmt) {
+	case DRM_FORMAT_ARGB8888:
+		*val = 2;
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+int sun4i_frontend_update_formats(struct sun4i_frontend *frontend,
+				  struct drm_plane *plane, uint32_t out_fmt)
+{
+	struct drm_plane_state *state = plane->state;
+	struct drm_framebuffer *fb = state->fb;
+	u32 out_fmt_val;
+	u32 in_fmt_val;
+	int ret;
+
+	ret = sun4i_frontend_drm_format_to_input_fmt(fb->format->format,
+						     &in_fmt_val);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Invalid input format\n");
+		return ret;
+	}
+
+	ret = sun4i_frontend_drm_format_to_output_fmt(out_fmt, &out_fmt_val);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Invalid output format\n");
+		return ret;
+	}
+
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZPHASE_REG, 0x400);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZPHASE_REG, 0x400);
+
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTPHASE0_REG, 0x400);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTPHASE0_REG, 0x400);
+
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTPHASE1_REG, 0x400);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTPHASE1_REG, 0x400);
+
+	regmap_write(frontend->regs, SUN4I_FRONTEND_INPUT_FMT_REG,
+		     SUN4I_FRONTEND_INPUT_FMT_DATA_MOD(1) |
+		     SUN4I_FRONTEND_INPUT_FMT_DATA_FMT(5) |
+		     SUN4I_FRONTEND_INPUT_FMT_PS(1));
+	regmap_write(frontend->regs, SUN4I_FRONTEND_OUTPUT_FMT_REG,
+		     SUN4I_FRONTEND_OUTPUT_FMT_DATA_FMT(1));
+
+	return 0;
+}
+EXPORT_SYMBOL(sun4i_frontend_update_formats);
+
+void sun4i_frontend_update_coord(struct sun4i_frontend *frontend,
+				 struct drm_plane *plane)
+{
+	struct drm_plane_state *state = plane->state;
+
+	/* Set height and width */
+	DRM_DEBUG_DRIVER("Frontend size W: %u H: %u\n",
+			 state->crtc_w, state->crtc_h);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_INSIZE_REG,
+		     SUN4I_FRONTEND_INSIZE(state->src_h >> 16,
+					   state->src_w >> 16));
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_INSIZE_REG,
+		     SUN4I_FRONTEND_INSIZE(state->src_h >> 16,
+					   state->src_w >> 16));
+
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_OUTSIZE_REG,
+		     SUN4I_FRONTEND_OUTSIZE(state->crtc_h, state->crtc_w));
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_OUTSIZE_REG,
+		     SUN4I_FRONTEND_OUTSIZE(state->crtc_h, state->crtc_w));
+
+	DRM_DEBUG_DRIVER("Frontend horizontal scaling factor %d.%d\n", 1, 0);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZFACT_REG,
+		     state->src_w / state->crtc_w);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZFACT_REG,
+		     state->src_w / state->crtc_w);
+
+	DRM_DEBUG_DRIVER("Frontend vertical scaling factor %d.%d\n", 1, 0);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTFACT_REG,
+		     state->src_h / state->crtc_h);
+	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTFACT_REG,
+		     state->src_h / state->crtc_h);
+
+	regmap_write_bits(frontend->regs, SUN4I_FRONTEND_FRM_CTRL_REG,
+			  SUN4I_FRONTEND_FRM_CTRL_REG_RDY,
+			  SUN4I_FRONTEND_FRM_CTRL_REG_RDY);
+}
+EXPORT_SYMBOL(sun4i_frontend_update_coord);
+
+int sun4i_frontend_enable(struct sun4i_frontend *frontend)
+{
+	regmap_write_bits(frontend->regs, SUN4I_FRONTEND_FRM_CTRL_REG,
+			  SUN4I_FRONTEND_FRM_CTRL_FRM_START,
+			  SUN4I_FRONTEND_FRM_CTRL_FRM_START);
+
+	return 0;
+}
+EXPORT_SYMBOL(sun4i_frontend_enable);
+
+static struct regmap_config sun4i_frontend_regmap_config = {
+	.reg_bits	= 32,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.max_register	= 0x0a14,
+};
+
+static int sun4i_frontend_bind(struct device *dev, struct device *master,
+			 void *data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct sun4i_frontend *frontend;
+	struct drm_device *drm = data;
+	struct sun4i_drv *drv = drm->dev_private;
+	struct resource *res;
+	void __iomem *regs;
+
+	frontend = devm_kzalloc(dev, sizeof(*frontend), GFP_KERNEL);
+	if (!frontend)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, frontend);
+	frontend->dev = dev;
+	frontend->node = dev->of_node;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	frontend->regs = devm_regmap_init_mmio(dev, regs,
+					       &sun4i_frontend_regmap_config);
+	if (IS_ERR(frontend->regs)) {
+		dev_err(dev, "Couldn't create the frontend regmap\n");
+		return PTR_ERR(frontend->regs);
+	}
+
+	frontend->reset = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(frontend->reset)) {
+		dev_err(dev, "Couldn't get our reset line\n");
+		return PTR_ERR(frontend->reset);
+	}
+
+	frontend->bus_clk = devm_clk_get(dev, "ahb");
+	if (IS_ERR(frontend->bus_clk)) {
+		dev_err(dev, "Couldn't get our bus clock\n");
+		return PTR_ERR(frontend->bus_clk);
+	}
+
+	frontend->mod_clk = devm_clk_get(dev, "mod");
+	if (IS_ERR(frontend->mod_clk)) {
+		dev_err(dev, "Couldn't get our mod clock\n");
+		return PTR_ERR(frontend->mod_clk);
+	}
+
+	frontend->ram_clk = devm_clk_get(dev, "ram");
+	if (IS_ERR(frontend->ram_clk)) {
+		dev_err(dev, "Couldn't get our ram clock\n");
+		return PTR_ERR(frontend->ram_clk);
+	}
+
+	list_add_tail(&frontend->list, &drv->frontend_list);
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static void sun4i_frontend_unbind(struct device *dev, struct device *master,
+			    void *data)
+{
+	struct sun4i_frontend *frontend = dev_get_drvdata(dev);
+
+	list_del(&frontend->list);
+	pm_runtime_force_suspend(dev);
+}
+
+static const struct component_ops sun4i_frontend_ops = {
+	.bind	= sun4i_frontend_bind,
+	.unbind	= sun4i_frontend_unbind,
+};
+
+static int sun4i_frontend_probe(struct platform_device *pdev)
+{
+	return component_add(&pdev->dev, &sun4i_frontend_ops);
+}
+
+static int sun4i_frontend_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &sun4i_frontend_ops);
+
+	return 0;
+}
+
+static int sun4i_frontend_runtime_resume(struct device *dev)
+{
+	struct sun4i_frontend *frontend = dev_get_drvdata(dev);
+	int ret;
+
+	ret = reset_control_deassert(frontend->reset);
+	if (ret) {
+		dev_err(dev, "Couldn't deassert our reset line\n");
+		return ret;
+	}
+
+	clk_set_rate(frontend->mod_clk, 300000000);
+
+	clk_prepare_enable(frontend->bus_clk);
+	clk_prepare_enable(frontend->mod_clk);
+	clk_prepare_enable(frontend->ram_clk);
+
+	regmap_update_bits(frontend->regs, SUN4I_FRONTEND_EN_REG,
+			   SUN4I_FRONTEND_EN_EN,
+			   SUN4I_FRONTEND_EN_EN);
+
+	regmap_update_bits(frontend->regs, SUN4I_FRONTEND_BYPASS_REG,
+			   SUN4I_FRONTEND_BYPASS_CSC_EN,
+			   SUN4I_FRONTEND_BYPASS_CSC_EN);
+
+	sun4i_frontend_scaler_init(frontend);
+
+	return 0;
+}
+
+static int sun4i_frontend_runtime_suspend(struct device *dev)
+{
+	struct sun4i_frontend *frontend = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(frontend->ram_clk);
+	clk_disable_unprepare(frontend->mod_clk);
+	clk_disable_unprepare(frontend->bus_clk);
+
+	reset_control_assert(frontend->reset);
+
+	return 0;
+}
+
+static const struct dev_pm_ops sun4i_frontend_pm_ops = {
+	.runtime_resume		= sun4i_frontend_runtime_resume,
+	.runtime_suspend	= sun4i_frontend_runtime_suspend,
+};
+
+static const struct of_device_id sun4i_frontend_of_table[] = {
+	{ .compatible = "allwinner,sun5i-a13-display-frontend" },
+	{ .compatible = "allwinner,sun6i-a31-display-frontend" },
+	{ .compatible = "allwinner,sun8i-a33-display-frontend" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sun4i_frontend_of_table);
+
+static struct platform_driver sun4i_frontend_driver = {
+	.probe		= sun4i_frontend_probe,
+	.remove		= sun4i_frontend_remove,
+	.driver		= {
+		.name		= "sun4i-frontend",
+		.of_match_table	= sun4i_frontend_of_table,
+		.pm		= &sun4i_frontend_pm_ops,
+	},
+};
+module_platform_driver(sun4i_frontend_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Allwinner A10 Display Engine Frontend Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/sun4i/sun4i_frontend.h b/drivers/gpu/drm/sun4i/sun4i_frontend.h
new file mode 100644
index 000000000000..5adc2c7266bc
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun4i_frontend.h
@@ -0,0 +1,96 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017 Free Electrons
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#ifndef _SUN4I_FRONTEND_H_
+#define _SUN4I_FRONTEND_H_
+
+#include <linux/list.h>
+
+#define SUN4I_FRONTEND_EN_REG			0x000
+#define SUN4I_FRONTEND_EN_EN				BIT(0)
+
+#define SUN4I_FRONTEND_FRM_CTRL_REG		0x004
+#define SUN4I_FRONTEND_FRM_CTRL_FRM_START		BIT(16)
+#define SUN4I_FRONTEND_FRM_CTRL_COEF_RDY		BIT(1)
+#define SUN4I_FRONTEND_FRM_CTRL_REG_RDY			BIT(0)
+
+#define SUN4I_FRONTEND_BYPASS_REG		0x008
+#define SUN4I_FRONTEND_BYPASS_CSC_EN			BIT(1)
+
+#define SUN4I_FRONTEND_BUF_ADDR0_REG		0x020
+
+#define SUN4I_FRONTEND_LINESTRD0_REG		0x040
+
+#define SUN4I_FRONTEND_INPUT_FMT_REG		0x04c
+#define SUN4I_FRONTEND_INPUT_FMT_DATA_MOD(mod)		((mod) << 8)
+#define SUN4I_FRONTEND_INPUT_FMT_DATA_FMT(fmt)		((fmt) << 4)
+#define SUN4I_FRONTEND_INPUT_FMT_PS(ps)			(ps)
+
+#define SUN4I_FRONTEND_OUTPUT_FMT_REG		0x05c
+#define SUN4I_FRONTEND_OUTPUT_FMT_DATA_FMT(fmt)		(fmt)
+
+#define SUN4I_FRONTEND_CH0_INSIZE_REG		0x100
+#define SUN4I_FRONTEND_INSIZE(h, w)			((((h) - 1) << 16) | (((w) - 1)))
+
+#define SUN4I_FRONTEND_CH0_OUTSIZE_REG		0x104
+#define SUN4I_FRONTEND_OUTSIZE(h, w)			((((h) - 1) << 16) | (((w) - 1)))
+
+#define SUN4I_FRONTEND_CH0_HORZFACT_REG		0x108
+#define SUN4I_FRONTEND_HORZFACT(i, f)			(((i) << 16) | (f))
+
+#define SUN4I_FRONTEND_CH0_VERTFACT_REG		0x10c
+#define SUN4I_FRONTEND_VERTFACT(i, f)			(((i) << 16) | (f))
+
+#define SUN4I_FRONTEND_CH0_HORZPHASE_REG	0x110
+#define SUN4I_FRONTEND_CH0_VERTPHASE0_REG	0x114
+#define SUN4I_FRONTEND_CH0_VERTPHASE1_REG	0x118
+
+#define SUN4I_FRONTEND_CH1_INSIZE_REG		0x200
+#define SUN4I_FRONTEND_CH1_OUTSIZE_REG		0x204
+#define SUN4I_FRONTEND_CH1_HORZFACT_REG		0x208
+#define SUN4I_FRONTEND_CH1_VERTFACT_REG		0x20c
+
+#define SUN4I_FRONTEND_CH1_HORZPHASE_REG	0x210
+#define SUN4I_FRONTEND_CH1_VERTPHASE0_REG	0x214
+#define SUN4I_FRONTEND_CH1_VERTPHASE1_REG	0x218
+
+#define SUN4I_FRONTEND_CH0_HORZCOEF0_REG(i)	(0x400 + i * 4)
+#define SUN4I_FRONTEND_CH0_HORZCOEF1_REG(i)	(0x480 + i * 4)
+#define SUN4I_FRONTEND_CH0_VERTCOEF_REG(i)	(0x500 + i * 4)
+#define SUN4I_FRONTEND_CH1_HORZCOEF0_REG(i)	(0x600 + i * 4)
+#define SUN4I_FRONTEND_CH1_HORZCOEF1_REG(i)	(0x680 + i * 4)
+#define SUN4I_FRONTEND_CH1_VERTCOEF_REG(i)	(0x700 + i * 4)
+
+struct clk;
+struct device_node;
+struct drm_plane;
+struct regmap;
+struct reset_control;
+
+struct sun4i_frontend {
+	struct list_head	list;
+	struct device		*dev;
+	struct device_node	*node;
+
+	struct clk		*bus_clk;
+	struct clk		*mod_clk;
+	struct clk		*ram_clk;
+	struct regmap		*regs;
+	struct reset_control	*reset;
+};
+
+int sun4i_frontend_init(struct sun4i_frontend *frontend);
+void sun4i_frontend_exit(struct sun4i_frontend *frontend);
+int sun4i_frontend_enable(struct sun4i_frontend *frontend);
+
+void sun4i_frontend_update_buffer(struct sun4i_frontend *frontend,
+				  struct drm_plane *plane);
+void sun4i_frontend_update_coord(struct sun4i_frontend *frontend,
+				 struct drm_plane *plane);
+int sun4i_frontend_update_formats(struct sun4i_frontend *frontend,
+				  struct drm_plane *plane, uint32_t out_fmt);
+
+#endif /* _SUN4I_FRONTEND_H_ */