staging: drm/imx: ipu-di: add comments explaining signal generator configuration

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/imx-drm/ipu-v3/ipu-di.c b/drivers/staging/imx-drm/ipu-v3/ipu-di.c
index ec340da..26534b7 100644 (file)
--- a/drivers/staging/imx-drm/ipu-v3/ipu-di.c
+++ b/drivers/staging/imx-drm/ipu-v3/ipu-di.c
@@ -413,9 +413,11 @@ static void ipu_di_sync_config_noninterlaced(struct ipu_di *di,
                sig->v_end_width;
        struct di_sync_config cfg[] = {
                {
+                       /* 1: INT_HSYNC */
                        .run_count = h_total - 1,
                        .run_src = DI_SYNC_CLK,
                } , {
+                       /* PIN2: HSYNC */
                        .run_count = h_total - 1,
                        .run_src = DI_SYNC_CLK,
                        .offset_count = div * sig->v_to_h_sync,
@@ -424,23 +426,28 @@ static void ipu_di_sync_config_noninterlaced(struct ipu_di *di,
                        .cnt_polarity_trigger_src = DI_SYNC_CLK,
                        .cnt_down = sig->h_sync_width * 2,
                } , {
+                       /* PIN3: VSYNC */
                        .run_count = v_total - 1,
                        .run_src = DI_SYNC_INT_HSYNC,
                        .cnt_polarity_gen_en = 1,
                        .cnt_polarity_trigger_src = DI_SYNC_INT_HSYNC,
                        .cnt_down = sig->v_sync_width * 2,
                } , {
+                       /* 4: Line Active */
                        .run_src = DI_SYNC_HSYNC,
                        .offset_count = sig->v_sync_width + sig->v_start_width,
                        .offset_src = DI_SYNC_HSYNC,
                        .repeat_count = sig->height,
                        .cnt_clr_src = DI_SYNC_VSYNC,
                } , {
+                       /* 5: DE, referenced by DC */
                        .run_src = DI_SYNC_CLK,
                        .offset_count = sig->h_sync_width + sig->h_start_width,
                        .offset_src = DI_SYNC_CLK,
                        .repeat_count = sig->width,
-                       .cnt_clr_src = 5,
+                       .cnt_clr_src = 5, /* Line Active */
+               } , {
+                       /* unused */
                } , {
                        /* unused */
                } , {