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

From: Robert Chiras
Date: Wed Jan 09 2019 - 09:14:50 EST


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 | 44 +++++++++++++++++++++++++++++++++---
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, 114 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index 24b1f0c..f0648ce 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -101,8 +101,11 @@ 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) {
@@ -130,6 +133,9 @@ 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);

@@ -139,12 +145,15 @@ 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
@@ -210,8 +219,9 @@ 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;

@@ -235,6 +245,11 @@ 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,
+ "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);
@@ -287,6 +302,7 @@ 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 */
@@ -310,6 +326,8 @@ 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;

@@ -332,4 +350,24 @@ 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);
+ }
}
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
index 88ba003..9a73564 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
@@ -106,9 +106,25 @@ 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);
@@ -134,6 +150,9 @@ 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,
@@ -231,16 +250,33 @@ 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 5d0883f..71238ad 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.h
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.h
@@ -35,8 +35,10 @@ 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;
struct drm_fbdev_cma *fbdev;
};

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_out.c b/drivers/gpu/drm/mxsfb/mxsfb_out.c
index e5edf01..ed0d8d3 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_out.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_out.c
@@ -30,7 +30,8 @@
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)
@@ -85,22 +86,23 @@ 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 66a6ba9..c5b5e40 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_regs.h
+++ b/drivers/gpu/drm/mxsfb/mxsfb_regs.h
@@ -22,19 +22,31 @@

#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)
@@ -53,12 +65,15 @@
#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