imx-drm: core: handling of DI clock flags to ipu_crtc_mode_set()

We do not need to track the state of the IPU DI's clock flags by having
each display bridge calling back into imx-drm-core, and then back out
into ipuv3-crtc.c.

ipuv3-crtc can instead just scan the list of encoders to retrieve their
type, and build up a picture of which types of encoders are attached.
We can then use this information to configure the IPU DI clocking mode
without any uncertainty - if we have multiple bridges connected to the
same DI, if one of them requires a synchronous DI clock, that's what we
must use.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

3 files changed, 25 insertions, 20 deletions

diff --git a/drivers/gpu/drm/imx/imx-drm-core.c b/drivers/gpu/drm/imx/imx-drm-core.c
index 06cd2e516db6..a002f53aab0e 100644
--- a/drivers/gpu/drm/imx/imx-drm-core.c
+++ b/drivers/gpu/drm/imx/imx-drm-core.c
@@ -116,8 +116,7 @@ int imx_drm_panel_format_pins(struct drm_encoder *encoder,
         helper = &imx_crtc->imx_drm_helper_funcs;
         if (helper->set_interface_pix_fmt)
                 return helper->set_interface_pix_fmt(encoder->crtc,
-                                encoder->encoder_type, interface_pix_fmt,
-                                hsync_pin, vsync_pin);
+                                interface_pix_fmt, hsync_pin, vsync_pin);
         return 0;
 }
 EXPORT_SYMBOL_GPL(imx_drm_panel_format_pins);
diff --git a/drivers/gpu/drm/imx/imx-drm.h b/drivers/gpu/drm/imx/imx-drm.h
index 7453ae00c412..3c559ccd6af0 100644
--- a/drivers/gpu/drm/imx/imx-drm.h
+++ b/drivers/gpu/drm/imx/imx-drm.h
@@ -17,7 +17,7 @@ int imx_drm_crtc_id(struct imx_drm_crtc *crtc);
 struct imx_drm_crtc_helper_funcs {
         int (*enable_vblank)(struct drm_crtc *crtc);
         void (*disable_vblank)(struct drm_crtc *crtc);
-        int (*set_interface_pix_fmt)(struct drm_crtc *crtc, u32 encoder_type,
+        int (*set_interface_pix_fmt)(struct drm_crtc *crtc,
                         u32 pix_fmt, int hsync_pin, int vsync_pin);
         const struct drm_crtc_helper_funcs *crtc_helper_funcs;
         const struct drm_crtc_funcs *crtc_funcs;
diff --git a/drivers/gpu/drm/imx/ipuv3-crtc.c b/drivers/gpu/drm/imx/ipuv3-crtc.c
index c1fc3735913d..98551e356e12 100644
--- a/drivers/gpu/drm/imx/ipuv3-crtc.c
+++ b/drivers/gpu/drm/imx/ipuv3-crtc.c
@@ -46,7 +46,6 @@ struct ipu_crtc {
         struct drm_framebuffer  *newfb;
         int                     irq;
         u32                     interface_pix_fmt;
-        unsigned long           di_clkflags;
         int                     di_hsync_pin;
         int                     di_vsync_pin;
 };
@@ -141,22 +140,42 @@ static int ipu_crtc_mode_set(struct drm_crtc *crtc,
                                int x, int y,
                                struct drm_framebuffer *old_fb)
 {
+        struct drm_device *dev = crtc->dev;
+        struct drm_encoder *encoder;
         struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
-        int ret;
         struct ipu_di_signal_cfg sig_cfg = {};
+        unsigned long encoder_types = 0;
         u32 out_pixel_fmt;
+        int ret;
 
         dev_dbg(ipu_crtc->dev, "%s: mode->hdisplay: %d\n", __func__,
                         mode->hdisplay);
         dev_dbg(ipu_crtc->dev, "%s: mode->vdisplay: %d\n", __func__,
                         mode->vdisplay);
 
+        list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
+                if (encoder->crtc == crtc)
+                        encoder_types |= BIT(encoder->encoder_type);
+
+        dev_dbg(ipu_crtc->dev, "%s: attached to encoder types 0x%lx\n",
+                __func__, encoder_types);
+
+        /*
+         * If we have DAC, TVDAC or LDB, then we need the IPU DI clock
+         * to be the same as the LDB DI clock.
+         */
+        if (encoder_types & (BIT(DRM_MODE_ENCODER_DAC) |
+                             BIT(DRM_MODE_ENCODER_TVDAC) |
+                             BIT(DRM_MODE_ENCODER_LVDS)))
+                sig_cfg.clkflags = IPU_DI_CLKMODE_SYNC | IPU_DI_CLKMODE_EXT;
+        else
+                sig_cfg.clkflags = 0;
+
         out_pixel_fmt = ipu_crtc->interface_pix_fmt;
 
         sig_cfg.enable_pol = 1;
         sig_cfg.clk_pol = 0;
         sig_cfg.pixel_fmt = out_pixel_fmt;
-        sig_cfg.clkflags = ipu_crtc->di_clkflags;
         sig_cfg.v_to_h_sync = 0;
         sig_cfg.hsync_pin = ipu_crtc->di_hsync_pin;
         sig_cfg.vsync_pin = ipu_crtc->di_vsync_pin;
@@ -271,7 +290,7 @@ static void ipu_disable_vblank(struct drm_crtc *crtc)
         ipu_crtc->newfb = NULL;
 }
 
-static int ipu_set_interface_pix_fmt(struct drm_crtc *crtc, u32 encoder_type,
+static int ipu_set_interface_pix_fmt(struct drm_crtc *crtc,
                 u32 pixfmt, int hsync_pin, int vsync_pin)
 {
         struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
@@ -280,19 +299,6 @@ static int ipu_set_interface_pix_fmt(struct drm_crtc *crtc, u32 encoder_type,
         ipu_crtc->di_hsync_pin = hsync_pin;
         ipu_crtc->di_vsync_pin = vsync_pin;
 
-        switch (encoder_type) {
-        case DRM_MODE_ENCODER_DAC:
-        case DRM_MODE_ENCODER_TVDAC:
-        case DRM_MODE_ENCODER_LVDS:
-                ipu_crtc->di_clkflags = IPU_DI_CLKMODE_SYNC |
-                        IPU_DI_CLKMODE_EXT;
-                break;
-        case DRM_MODE_ENCODER_TMDS:
-        case DRM_MODE_ENCODER_NONE:
-                ipu_crtc->di_clkflags = 0;
-                break;
-        }
-
         return 0;
 }