drm/sun4i: hdmi: Add support for controller hardware variants

The HDMI controller found in earlier Allwinner SoCs have slight
differences between the A10, A10s, and the A31:

  - Need different initial values for the PLL related registers

  - Different behavior of the DDC and TMDS clocks

  - Different register layout for the DDC portion

  - Separate DDC parent clock on the A31

  - Explicit reset control

For the A31, the HDMI TMDS clock has a different value offset for
the divider. The HDMI DDC block is different from the one in the
other SoCs. As far as the DDC clock goes, it has no pre-divider,
as it is clocked from a slower parent clock, not the TMDS clock.
The divider offset from the register value is different. And the
clock control register is at a different offset.

A new variant data structure is created to store pointers to the
above functions, structures, and the different initial values.
Another flag notates whether there is a separate DDC parent clock.
If not, the TMDS clock is passed to the DDC clock create function,
as before.

Regmap fields are used to deal with the different register layout
of the DDC block.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171010032008.682-8-wens@csie.org

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c
index e8d4c311b80d..1b6b37aefc38 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_tmds_clk.c
@@ -18,6 +18,8 @@
 struct sun4i_tmds {
 	struct clk_hw		hw;
 	struct sun4i_hdmi	*hdmi;
+
+	u8			div_offset;
 };
 
 static inline struct sun4i_tmds *hw_to_tmds(struct clk_hw *hw)
@@ -28,6 +30,7 @@ static inline struct sun4i_tmds *hw_to_tmds(struct clk_hw *hw)
 
 static unsigned long sun4i_tmds_calc_divider(unsigned long rate,
 					     unsigned long parent_rate,
+					     u8 div_offset,
 					     u8 *div,
 					     bool *half)
 {
@@ -35,7 +38,7 @@ static unsigned long sun4i_tmds_calc_divider(unsigned long rate,
 	u8 best_m = 0, m;
 	bool is_double;
 
-	for (m = 1; m < 16; m++) {
+	for (m = div_offset ?: 1; m < (16 + div_offset); m++) {
 		u8 d;
 
 		for (d = 1; d < 3; d++) {
@@ -67,6 +70,7 @@ static unsigned long sun4i_tmds_calc_divider(unsigned long rate,
 static int sun4i_tmds_determine_rate(struct clk_hw *hw,
 				     struct clk_rate_request *req)
 {
+	struct sun4i_tmds *tmds = hw_to_tmds(hw);
 	struct clk_hw *parent = NULL;
 	unsigned long best_parent = 0;
 	unsigned long rate = req->rate;
@@ -85,7 +89,8 @@ static int sun4i_tmds_determine_rate(struct clk_hw *hw,
 			continue;
 
 		for (i = 1; i < 3; i++) {
-			for (j = 1; j < 16; j++) {
+			for (j = tmds->div_offset ?: 1;
+			     j < (16 + tmds->div_offset); j++) {
 				unsigned long ideal = rate * i * j;
 				unsigned long rounded;
 
@@ -129,7 +134,7 @@ static unsigned long sun4i_tmds_recalc_rate(struct clk_hw *hw,
 		parent_rate /= 2;
 
 	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
-	reg = (reg >> 4) & 0xf;
+	reg = ((reg >> 4) & 0xf) + tmds->div_offset;
 	if (!reg)
 		reg = 1;
 
@@ -144,7 +149,8 @@ static int sun4i_tmds_set_rate(struct clk_hw *hw, unsigned long rate,
 	u32 reg;
 	u8 div;
 
-	sun4i_tmds_calc_divider(rate, parent_rate, &div, &half);
+	sun4i_tmds_calc_divider(rate, parent_rate, tmds->div_offset,
+				&div, &half);
 
 	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
 	reg &= ~SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
@@ -154,7 +160,7 @@ static int sun4i_tmds_set_rate(struct clk_hw *hw, unsigned long rate,
 
 	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
 	reg &= ~SUN4I_HDMI_PLL_CTRL_DIV_MASK;
-	writel(reg | SUN4I_HDMI_PLL_CTRL_DIV(div),
+	writel(reg | SUN4I_HDMI_PLL_CTRL_DIV(div - tmds->div_offset),
 	       tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
 
 	return 0;
@@ -221,6 +227,7 @@ int sun4i_tmds_create(struct sun4i_hdmi *hdmi)
 
 	tmds->hdmi = hdmi;
 	tmds->hw.init = &init;
+	tmds->div_offset = hdmi->variant->tmds_clk_div_offset;
 
 	hdmi->tmds_clk = devm_clk_register(hdmi->dev, &tmds->hw);
 	if (IS_ERR(hdmi->tmds_clk))