drm/sun4i: frontend: Rework a bit the phase data

The scaler filter phase setup in the allwinner kernel has two different
cases for setting up the scaler filter, the first one using different phase
parameters for the two channels, and the second one reusing the first
channel parameters on the second channel.

The allwinner kernel has a third option where the horizontal phase of the
second channel will be set to a different value than the vertical one (and
seems like it's the same value than one used on the first channel).
However, that code path seems to never be taken, so we can ignore it for
now, and it's essentially what we're doing so far as well.

Since we will have always the same values across each components of the
filter setup for a given channel, we can simplify a bit our frontend
structure by only storing the phase value we want to apply to a given
channel.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Jernej Skrabec <jernej.skrabec@siol.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20201015093642.261440-1-maxime@cerno.tech

drivers/gpu/drm/sun4i/sun4i_frontend.c

@@ -443,17 +443,17 @@ int sun4i_frontend_update_formats(struct sun4i_frontend *frontend,
 	 * related to the scaler FIR filter phase parameters.
 	 */
 	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_HORZPHASE_REG,
-		     frontend->data->ch_phase[0].horzphase);
+		     frontend->data->ch_phase[0]);
 	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_HORZPHASE_REG,
-		     frontend->data->ch_phase[1].horzphase);
+		     frontend->data->ch_phase[1]);
 	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTPHASE0_REG,
-		     frontend->data->ch_phase[0].vertphase[0]);
+		     frontend->data->ch_phase[0]);
 	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTPHASE0_REG,
-		     frontend->data->ch_phase[1].vertphase[0]);
+		     frontend->data->ch_phase[1]);
 	regmap_write(frontend->regs, SUN4I_FRONTEND_CH0_VERTPHASE1_REG,
-		     frontend->data->ch_phase[0].vertphase[1]);
+		     frontend->data->ch_phase[0]);
 	regmap_write(frontend->regs, SUN4I_FRONTEND_CH1_VERTPHASE1_REG,
-		     frontend->data->ch_phase[1].vertphase[1]);
+		     frontend->data->ch_phase[1]);
 
 	/*
 	 * Checking the input format is sufficient since we currently only
@@ -687,30 +687,12 @@ static const struct dev_pm_ops sun4i_frontend_pm_ops = {
 };
 
 static const struct sun4i_frontend_data sun4i_a10_frontend = {
-	.ch_phase		= {
-		{
-			.horzphase = 0,
-			.vertphase = { 0, 0 },
-		},
-		{
-			.horzphase = 0xfc000,
-			.vertphase = { 0xfc000, 0xfc000 },
-		},
-	},
+	.ch_phase		= { 0x000, 0xfc000 },
 	.has_coef_rdy		= true,
 };
 
 static const struct sun4i_frontend_data sun8i_a33_frontend = {
-	.ch_phase		= {
-		{
-			.horzphase = 0x400,
-			.vertphase = { 0x400, 0x400 },
-		},
-		{
-			.horzphase = 0x400,
-			.vertphase = { 0x400, 0x400 },
-		},
-	},
+	.ch_phase		= { 0x400, 0x400 },
 	.has_coef_access_ctrl	= true,
 };
 

drivers/gpu/drm/sun4i/sun4i_frontend.h

@@ -115,11 +115,7 @@ struct reset_control;
 struct sun4i_frontend_data {
 	bool	has_coef_access_ctrl;
 	bool	has_coef_rdy;
-
-	struct {
-		u32	horzphase;
-		u32	vertphase[2];
-	} ch_phase[2];
+	u32	ch_phase[2];
 };
 
 struct sun4i_frontend {