Re: [PATCH 01/10] drm/mxsfb: Update mxsfb to support a bridge

From: Guido Günther
Date: Sun Jul 21 2019 - 06:26:59 EST


Hi Robert,
On Wed, Jun 26, 2019 at 04:32:09PM +0300, Robert Chiras wrote:
> Currently, the MXSFB DRM driver only supports a panel. But, its output
> display signal can also be redirected to another encoder, like a DSI
> controller. In this case, that DSI controller may act like a drm_bridge.
> In order support this use-case too, this patch adds support for
> drm_bridge in mxsfb.
>
> Signed-off-by: Robert Chiras <robert.chiras@xxxxxxx>
> ---
> drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 46 +++++++++++++++++++++++++++++++++++---
> drivers/gpu/drm/mxsfb/mxsfb_drv.c | 46 +++++++++++++++++++++++++++++++++-----
> drivers/gpu/drm/mxsfb/mxsfb_drv.h | 4 +++-
> drivers/gpu/drm/mxsfb/mxsfb_out.c | 26 +++++++++++----------
> drivers/gpu/drm/mxsfb/mxsfb_regs.h | 15 +++++++++++++
> 5 files changed, 116 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
> index 93f4133..14bde024 100644
> --- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
> +++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
> @@ -93,8 +93,11 @@ static void mxsfb_set_bus_fmt(struct mxsfb_drm_private *mxsfb)
>
> reg = readl(mxsfb->base + LCDC_CTRL);
>
> - if (mxsfb->connector.display_info.num_bus_formats)
> - bus_format = mxsfb->connector.display_info.bus_formats[0];
> + if (mxsfb->connector->display_info.num_bus_formats)
> + bus_format = mxsfb->connector->display_info.bus_formats[0];
> +
> + DRM_DEV_DEBUG_DRIVER(drm->dev, "Using bus_format: 0x%08X\n",
> + bus_format);
>
> reg &= ~CTRL_BUS_WIDTH_MASK;
> switch (bus_format) {
> @@ -122,6 +125,9 @@ static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
> clk_prepare_enable(mxsfb->clk_disp_axi);
> clk_prepare_enable(mxsfb->clk);
>
> + writel(CTRL2_OUTSTANDING_REQS__REQ_16,
> + mxsfb->base + LCDC_V4_CTRL2 + REG_SET);
> +
> /* If it was disabled, re-enable the mode again */
> writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_SET);
>
> @@ -131,12 +137,15 @@ static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
> writel(reg, mxsfb->base + LCDC_VDCTRL4);
>
> writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_SET);
> + writel(CTRL1_RECOVERY_ON_UNDERFLOW, mxsfb->base + LCDC_CTRL1 + REG_SET);
> }
>
> static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
> {
> u32 reg;
>
> + writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_CLR);
> +
> /*
> * Even if we disable the controller here, it will still continue
> * until its FIFOs are running out of data
> @@ -202,8 +211,9 @@ static dma_addr_t mxsfb_get_fb_paddr(struct mxsfb_drm_private *mxsfb)
>
> static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
> {
> + struct drm_device *drm = mxsfb->pipe.crtc.dev;
> struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode;
> - const u32 bus_flags = mxsfb->connector.display_info.bus_flags;
> + const u32 bus_flags = mxsfb->connector->display_info.bus_flags;
> u32 vdctrl0, vsync_pulse_len, hsync_pulse_len;
> int err;
>
> @@ -227,6 +237,13 @@ static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
>
> clk_set_rate(mxsfb->clk, m->crtc_clock * 1000);
>
> + DRM_DEV_DEBUG_DRIVER(drm->dev, "Pixel clock: %dkHz (actual: %dkHz)\n",
> + m->crtc_clock,
> + (int)(clk_get_rate(mxsfb->clk) / 1000));
> + DRM_DEV_DEBUG_DRIVER(drm->dev, "Connector bus_flags: 0x%08X\n",
> + bus_flags);
> + DRM_DEV_DEBUG_DRIVER(drm->dev, "Mode flags: 0x%08X\n", m->flags);
> +
> writel(TRANSFER_COUNT_SET_VCOUNT(m->crtc_vdisplay) |
> TRANSFER_COUNT_SET_HCOUNT(m->crtc_hdisplay),
> mxsfb->base + mxsfb->devdata->transfer_count);
> @@ -279,6 +296,7 @@ void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb)
> dma_addr_t paddr;
>
> mxsfb_enable_axi_clk(mxsfb);
> + writel(0, mxsfb->base + LCDC_CTRL);
> mxsfb_crtc_mode_set_nofb(mxsfb);
>
> /* Write cur_buf as well to avoid an initial corrupt frame */
> @@ -302,6 +320,8 @@ void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
> {
> struct drm_simple_display_pipe *pipe = &mxsfb->pipe;
> struct drm_crtc *crtc = &pipe->crtc;
> + struct drm_framebuffer *fb = pipe->plane.state->fb;
> + struct drm_framebuffer *old_fb = old_state->fb;
> struct drm_pending_vblank_event *event;
> dma_addr_t paddr;
>
> @@ -324,4 +344,24 @@ void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
> writel(paddr, mxsfb->base + mxsfb->devdata->next_buf);
> mxsfb_disable_axi_clk(mxsfb);
> }
> +
> + if (!fb || !old_fb)
> + return;
> +
> + /*
> + * TODO: Currently, we only support pixel format change, but we need
> + * also to care about size changes too
> + */
> + if (old_fb->format->format != fb->format->format) {
> + struct drm_format_name_buf old_fmt_buf;
> + struct drm_format_name_buf new_fmt_buf;
> +
> + DRM_DEV_DEBUG_DRIVER(crtc->dev->dev,
> + "Switching pixel format: %s -> %s\n",
> + drm_get_format_name(old_fb->format->format,
> + &old_fmt_buf),
> + drm_get_format_name(fb->format->format,
> + &new_fmt_buf));
> + mxsfb_set_pixel_fmt(mxsfb, true);

This assumes mxsfb_set_pixel_fmt has two arguments which is being introduced
in the following commit. With that fixed:

Tested-by: Guido Günther <agx@xxxxxxxxxxx>

Cheers,
-- Guido

> + }
> }
> diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
> index 6fafc90..0d171e9 100644
> --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
> +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
> @@ -98,9 +98,25 @@ static void mxsfb_pipe_enable(struct drm_simple_display_pipe *pipe,
> struct drm_crtc_state *crtc_state,
> struct drm_plane_state *plane_state)
> {
> + struct drm_connector *connector;
> struct mxsfb_drm_private *mxsfb = drm_pipe_to_mxsfb_drm_private(pipe);
> struct drm_device *drm = pipe->plane.dev;
>
> + if (!mxsfb->connector) {
> + list_for_each_entry(connector,
> + &drm->mode_config.connector_list,
> + head)
> + if (connector->encoder == &mxsfb->pipe.encoder) {
> + mxsfb->connector = connector;
> + break;
> + }
> + }
> +
> + if (!mxsfb->connector) {
> + dev_warn(drm->dev, "No connector attached, using default\n");
> + mxsfb->connector = &mxsfb->panel_connector;
> + }
> +
> pm_runtime_get_sync(drm->dev);
> drm_panel_prepare(mxsfb->panel);
> mxsfb_crtc_enable(mxsfb);
> @@ -126,6 +142,9 @@ static void mxsfb_pipe_disable(struct drm_simple_display_pipe *pipe)
> drm_crtc_send_vblank_event(crtc, event);
> }
> spin_unlock_irq(&drm->event_lock);
> +
> + if (mxsfb->connector != &mxsfb->panel_connector)
> + mxsfb->connector = NULL;
> }
>
> static void mxsfb_pipe_update(struct drm_simple_display_pipe *pipe,
> @@ -223,16 +242,33 @@ static int mxsfb_load(struct drm_device *drm, unsigned long flags)
>
> ret = drm_simple_display_pipe_init(drm, &mxsfb->pipe, &mxsfb_funcs,
> mxsfb_formats, ARRAY_SIZE(mxsfb_formats), NULL,
> - &mxsfb->connector);
> + mxsfb->connector);
> if (ret < 0) {
> dev_err(drm->dev, "Cannot setup simple display pipe\n");
> goto err_vblank;
> }
>
> - ret = drm_panel_attach(mxsfb->panel, &mxsfb->connector);
> - if (ret) {
> - dev_err(drm->dev, "Cannot connect panel\n");
> - goto err_vblank;
> + /*
> + * Attach panel only if there is one.
> + * If there is no panel attach, it must be a bridge. In this case, we
> + * need a reference to its connector for a proper initialization.
> + * We will do this check in pipe->enable(), since the connector won't
> + * be attached to an encoder until then.
> + */
> +
> + if (mxsfb->panel) {
> + ret = drm_panel_attach(mxsfb->panel, mxsfb->connector);
> + if (ret) {
> + dev_err(drm->dev, "Cannot connect panel\n");
> + goto err_vblank;
> + }
> + } else if (mxsfb->bridge) {
> + ret = drm_simple_display_pipe_attach_bridge(&mxsfb->pipe,
> + mxsfb->bridge);
> + if (ret) {
> + dev_err(drm->dev, "Cannot connect bridge\n");
> + goto err_vblank;
> + }
> }
>
> drm->mode_config.min_width = MXSFB_MIN_XRES;
> diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.h b/drivers/gpu/drm/mxsfb/mxsfb_drv.h
> index d975300..0b65b51 100644
> --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.h
> +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.h
> @@ -27,8 +27,10 @@ struct mxsfb_drm_private {
> struct clk *clk_disp_axi;
>
> struct drm_simple_display_pipe pipe;
> - struct drm_connector connector;
> + struct drm_connector panel_connector;
> + struct drm_connector *connector;
> struct drm_panel *panel;
> + struct drm_bridge *bridge;
> };
>
> int mxsfb_setup_crtc(struct drm_device *dev);
> diff --git a/drivers/gpu/drm/mxsfb/mxsfb_out.c b/drivers/gpu/drm/mxsfb/mxsfb_out.c
> index 91e76f9..b9acf2b 100644
> --- a/drivers/gpu/drm/mxsfb/mxsfb_out.c
> +++ b/drivers/gpu/drm/mxsfb/mxsfb_out.c
> @@ -22,7 +22,8 @@
> static struct mxsfb_drm_private *
> drm_connector_to_mxsfb_drm_private(struct drm_connector *connector)
> {
> - return container_of(connector, struct mxsfb_drm_private, connector);
> + return container_of(connector, struct mxsfb_drm_private,
> + panel_connector);
> }
>
> static int mxsfb_panel_get_modes(struct drm_connector *connector)
> @@ -77,22 +78,23 @@ static const struct drm_connector_funcs mxsfb_panel_connector_funcs = {
> int mxsfb_create_output(struct drm_device *drm)
> {
> struct mxsfb_drm_private *mxsfb = drm->dev_private;
> - struct drm_panel *panel;
> int ret;
>
> - ret = drm_of_find_panel_or_bridge(drm->dev->of_node, 0, 0, &panel, NULL);
> + ret = drm_of_find_panel_or_bridge(drm->dev->of_node, 0, 0,
> + &mxsfb->panel, &mxsfb->bridge);
> if (ret)
> return ret;
>
> - mxsfb->connector.dpms = DRM_MODE_DPMS_OFF;
> - mxsfb->connector.polled = 0;
> - drm_connector_helper_add(&mxsfb->connector,
> - &mxsfb_panel_connector_helper_funcs);
> - ret = drm_connector_init(drm, &mxsfb->connector,
> - &mxsfb_panel_connector_funcs,
> - DRM_MODE_CONNECTOR_Unknown);
> - if (!ret)
> - mxsfb->panel = panel;
> + if (mxsfb->panel) {
> + mxsfb->connector = &mxsfb->panel_connector;
> + mxsfb->connector->dpms = DRM_MODE_DPMS_OFF;
> + mxsfb->connector->polled = 0;
> + drm_connector_helper_add(mxsfb->connector,
> + &mxsfb_panel_connector_helper_funcs);
> + ret = drm_connector_init(drm, mxsfb->connector,
> + &mxsfb_panel_connector_funcs,
> + DRM_MODE_CONNECTOR_Unknown);
> + }
>
> return ret;
> }
> diff --git a/drivers/gpu/drm/mxsfb/mxsfb_regs.h b/drivers/gpu/drm/mxsfb/mxsfb_regs.h
> index 932d7ea..71426aa 100644
> --- a/drivers/gpu/drm/mxsfb/mxsfb_regs.h
> +++ b/drivers/gpu/drm/mxsfb/mxsfb_regs.h
> @@ -14,19 +14,31 @@
>
> #define LCDC_CTRL 0x00
> #define LCDC_CTRL1 0x10
> +#define LCDC_V4_CTRL2 0x20
> #define LCDC_V3_TRANSFER_COUNT 0x20
> #define LCDC_V4_TRANSFER_COUNT 0x30
> #define LCDC_V4_CUR_BUF 0x40
> #define LCDC_V4_NEXT_BUF 0x50
> #define LCDC_V3_CUR_BUF 0x30
> #define LCDC_V3_NEXT_BUF 0x40
> +#define LCDC_TIMING 0x60
> #define LCDC_VDCTRL0 0x70
> #define LCDC_VDCTRL1 0x80
> #define LCDC_VDCTRL2 0x90
> #define LCDC_VDCTRL3 0xa0
> #define LCDC_VDCTRL4 0xb0
> +#define LCDC_DVICTRL0 0xc0
> +#define LCDC_DVICTRL1 0xd0
> +#define LCDC_DVICTRL2 0xe0
> +#define LCDC_DVICTRL3 0xf0
> +#define LCDC_DVICTRL4 0x100
> +#define LCDC_V4_DATA 0x180
> +#define LCDC_V3_DATA 0x1b0
> #define LCDC_V4_DEBUG0 0x1d0
> #define LCDC_V3_DEBUG0 0x1f0
> +#define LCDC_AS_CTRL 0x210
> +#define LCDC_AS_BUF 0x220
> +#define LCDC_AS_NEXT_BUF 0x230
>
> #define CTRL_SFTRST (1 << 31)
> #define CTRL_CLKGATE (1 << 30)
> @@ -45,12 +57,15 @@
> #define CTRL_DF24 (1 << 1)
> #define CTRL_RUN (1 << 0)
>
> +#define CTRL1_RECOVERY_ON_UNDERFLOW (1 << 24)
> #define CTRL1_FIFO_CLEAR (1 << 21)
> #define CTRL1_SET_BYTE_PACKAGING(x) (((x) & 0xf) << 16)
> #define CTRL1_GET_BYTE_PACKAGING(x) (((x) >> 16) & 0xf)
> #define CTRL1_CUR_FRAME_DONE_IRQ_EN (1 << 13)
> #define CTRL1_CUR_FRAME_DONE_IRQ (1 << 9)
>
> +#define CTRL2_OUTSTANDING_REQS__REQ_16 (4 << 21)
> +
> #define TRANSFER_COUNT_SET_VCOUNT(x) (((x) & 0xffff) << 16)
> #define TRANSFER_COUNT_GET_VCOUNT(x) (((x) >> 16) & 0xffff)
> #define TRANSFER_COUNT_SET_HCOUNT(x) ((x) & 0xffff)
> --
> 2.7.4
>
>
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