[PATCH 11/15] drm/sun4i: Add support for H3 HDMI PHY variant

[Jernej Skrabec <jernej.skrabec@siol.net>]

While A83T HDMI PHY seems to be just customized Synopsys HDMI PHY, H3
HDMI PHY is completely custom PHY.

However, they still have many things in common like clock and reset
setup, setting sync polarity and more.

Add support for H3 HDMI PHY variant.

While documentation exists for this PHY variant, it doesn't go in great
details. Because of that, almost all settings are copied from BSP linux
4.4. Interestingly, those settings are slightly different to those found
in a older BSP with Linux 3.4. For now, no user visible difference was
found between them.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
---
 drivers/gpu/drm/sun4i/Makefile             |   1 +
 drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h      |   6 +
 drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c     | 263 ++++++++++++++++++++++++++++-
 drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c | 130 ++++++++++++++
 4 files changed, 397 insertions(+), 3 deletions(-)
 create mode 100644 drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c

diff --git a/drivers/gpu/drm/sun4i/Makefile b/drivers/gpu/drm/sun4i/Makefile
index 1610e748119b..330843ce4280 100644
--- a/drivers/gpu/drm/sun4i/Makefile
+++ b/drivers/gpu/drm/sun4i/Makefile
@@ -12,6 +12,7 @@ sun4i-drm-hdmi-y		+= sun4i_hdmi_tmds_clk.o
 
 sun8i-drm-hdmi-y		+= sun8i_dw_hdmi.o
 sun8i-drm-hdmi-y		+= sun8i_hdmi_phy.o
+sun8i-drm-hdmi-y		+= sun8i_hdmi_phy_clk.o
 
 sun8i-mixer-y			+= sun8i_mixer.o sun8i_ui_layer.o \
 				   sun8i_vi_layer.o sun8i_ui_scaler.o \
diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
index 4d625adf4b65..5b05b67fc2af 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
@@ -145,6 +145,7 @@
 struct sun8i_hdmi_phy;
 
 struct sun8i_hdmi_phy_variant {
+	bool has_phy_clk;
 	void (*phy_init)(struct sun8i_hdmi_phy *phy);
 	void (*phy_disable)(struct dw_hdmi *hdmi,
 			    struct sun8i_hdmi_phy *phy);
@@ -156,6 +157,9 @@ struct sun8i_hdmi_phy_variant {
 struct sun8i_hdmi_phy {
 	struct clk			*clk_bus;
 	struct clk			*clk_mod;
+	struct clk			*clk_phy;
+	struct clk			*clk_pll0;
+	unsigned int			rcal;
 	struct regmap			*regs;
 	struct reset_control		*rst_phy;
 	struct sun8i_hdmi_phy_variant	*variant;
@@ -183,4 +187,6 @@ void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi *hdmi);
 void sun8i_hdmi_phy_init(struct sun8i_hdmi_phy *phy);
 const struct dw_hdmi_phy_ops *sun8i_hdmi_phy_get_ops(void);
 
+int sun8i_phy_clk_create(struct sun8i_hdmi_phy *phy, struct device *dev);
+
 #endif /* _SUN8I_DW_HDMI_H_ */
diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
index 1bf96b04545b..810c4da49a68 100644
--- a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
+++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2018 Jernej Skrabec <jernej.skrabec@siol.net>
  */
 
+#include <linux/delay.h>
 #include <linux/of_address.h>
 
 #include "sun8i_dw_hdmi.h"
@@ -73,7 +74,147 @@ static int sun8i_hdmi_phy_config_a83t(struct dw_hdmi *hdmi,
 	dw_hdmi_phy_gen2_txpwron(hdmi, 1);
 
 	return 0;
-};
+}
+
+static int sun8i_hdmi_phy_config_h3(struct dw_hdmi *hdmi,
+				    struct sun8i_hdmi_phy *phy,
+				    unsigned int clk_rate)
+{
+	u32 pll_cfg1_init;
+	u32 pll_cfg2_init;
+	u32 ana_cfg1_end;
+	u32 ana_cfg2_init;
+	u32 ana_cfg3_init;
+	u32 b_offset = 0;
+	u32 val;
+
+	/* bandwidth / frequency independent settings */
+
+	pll_cfg1_init = SUN8I_HDMI_PHY_PLL_CFG1_LDO2_EN |
+			SUN8I_HDMI_PHY_PLL_CFG1_LDO1_EN |
+			SUN8I_HDMI_PHY_PLL_CFG1_LDO_VSET(7) |
+			SUN8I_HDMI_PHY_PLL_CFG1_UNKNOWN(1) |
+			SUN8I_HDMI_PHY_PLL_CFG1_PLLDBEN |
+			SUN8I_HDMI_PHY_PLL_CFG1_CS |
+			SUN8I_HDMI_PHY_PLL_CFG1_CP_S(2) |
+			SUN8I_HDMI_PHY_PLL_CFG1_CNT_INT(63) |
+			SUN8I_HDMI_PHY_PLL_CFG1_BWS;
+
+	pll_cfg2_init = SUN8I_HDMI_PHY_PLL_CFG2_SV_H |
+			SUN8I_HDMI_PHY_PLL_CFG2_VCOGAIN_EN |
+			SUN8I_HDMI_PHY_PLL_CFG2_SDIV2;
+
+	ana_cfg1_end = SUN8I_HDMI_PHY_ANA_CFG1_REG_SVBH(1) |
+		       SUN8I_HDMI_PHY_ANA_CFG1_AMP_OPT |
+		       SUN8I_HDMI_PHY_ANA_CFG1_EMP_OPT |
+		       SUN8I_HDMI_PHY_ANA_CFG1_AMPCK_OPT |
+		       SUN8I_HDMI_PHY_ANA_CFG1_EMPCK_OPT |
+		       SUN8I_HDMI_PHY_ANA_CFG1_ENRCAL |
+		       SUN8I_HDMI_PHY_ANA_CFG1_ENCALOG |
+		       SUN8I_HDMI_PHY_ANA_CFG1_REG_SCKTMDS |
+		       SUN8I_HDMI_PHY_ANA_CFG1_TMDSCLK_EN |
+		       SUN8I_HDMI_PHY_ANA_CFG1_TXEN_MASK |
+		       SUN8I_HDMI_PHY_ANA_CFG1_TXEN_ALL |
+		       SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDSCLK |
+		       SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS2 |
+		       SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS1 |
+		       SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS0 |
+		       SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS2 |
+		       SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS1 |
+		       SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS0 |
+		       SUN8I_HDMI_PHY_ANA_CFG1_CKEN |
+		       SUN8I_HDMI_PHY_ANA_CFG1_LDOEN |
+		       SUN8I_HDMI_PHY_ANA_CFG1_ENVBS |
+		       SUN8I_HDMI_PHY_ANA_CFG1_ENBI;
+
+	ana_cfg2_init = SUN8I_HDMI_PHY_ANA_CFG2_M_EN |
+			SUN8I_HDMI_PHY_ANA_CFG2_REG_DENCK |
+			SUN8I_HDMI_PHY_ANA_CFG2_REG_DEN |
+			SUN8I_HDMI_PHY_ANA_CFG2_REG_CKSS(1) |
+			SUN8I_HDMI_PHY_ANA_CFG2_REG_CSMPS(1);
+
+	ana_cfg3_init = SUN8I_HDMI_PHY_ANA_CFG3_REG_WIRE(0x3e0) |
+			SUN8I_HDMI_PHY_ANA_CFG3_SDAEN |
+			SUN8I_HDMI_PHY_ANA_CFG3_SCLEN;
+
+	/* bandwidth / frequency dependent settings */
+	if (clk_rate <= 27000000) {
+		pll_cfg1_init |= SUN8I_HDMI_PHY_PLL_CFG1_HV_IS_33 |
+				 SUN8I_HDMI_PHY_PLL_CFG1_CNT_INT(32);
+		pll_cfg2_init |= SUN8I_HDMI_PHY_PLL_CFG2_VCO_S(4) |
+				 SUN8I_HDMI_PHY_PLL_CFG2_S(4);
+		ana_cfg1_end |= SUN8I_HDMI_PHY_ANA_CFG1_REG_CALSW;
+		ana_cfg2_init |= SUN8I_HDMI_PHY_ANA_CFG2_REG_SLV(4) |
+				 SUN8I_HDMI_PHY_ANA_CFG2_REG_RESDI(phy->rcal);
+		ana_cfg3_init |= SUN8I_HDMI_PHY_ANA_CFG3_REG_AMPCK(3) |
+				 SUN8I_HDMI_PHY_ANA_CFG3_REG_AMP(5);
+	} else if (clk_rate <= 74250000) {
+		pll_cfg1_init |= SUN8I_HDMI_PHY_PLL_CFG1_HV_IS_33 |
+				 SUN8I_HDMI_PHY_PLL_CFG1_CNT_INT(32);
+		pll_cfg2_init |= SUN8I_HDMI_PHY_PLL_CFG2_VCO_S(4) |
+				 SUN8I_HDMI_PHY_PLL_CFG2_S(5);
+		ana_cfg1_end |= SUN8I_HDMI_PHY_ANA_CFG1_REG_CALSW;
+		ana_cfg2_init |= SUN8I_HDMI_PHY_ANA_CFG2_REG_SLV(4) |
+				 SUN8I_HDMI_PHY_ANA_CFG2_REG_RESDI(phy->rcal);
+		ana_cfg3_init |= SUN8I_HDMI_PHY_ANA_CFG3_REG_AMPCK(5) |
+				 SUN8I_HDMI_PHY_ANA_CFG3_REG_AMP(7);
+	} else if (clk_rate <= 148500000) {
+		pll_cfg1_init |= SUN8I_HDMI_PHY_PLL_CFG1_HV_IS_33 |
+				 SUN8I_HDMI_PHY_PLL_CFG1_CNT_INT(32);
+		pll_cfg2_init |= SUN8I_HDMI_PHY_PLL_CFG2_VCO_S(4) |
+				 SUN8I_HDMI_PHY_PLL_CFG2_S(6);
+		ana_cfg2_init |= SUN8I_HDMI_PHY_ANA_CFG2_REG_BIGSWCK |
+				 SUN8I_HDMI_PHY_ANA_CFG2_REG_BIGSW |
+				 SUN8I_HDMI_PHY_ANA_CFG2_REG_SLV(2);
+		ana_cfg3_init |= SUN8I_HDMI_PHY_ANA_CFG3_REG_AMPCK(7) |
+				 SUN8I_HDMI_PHY_ANA_CFG3_REG_AMP(9);
+	} else {
+		b_offset = 2;
+		pll_cfg1_init |= SUN8I_HDMI_PHY_PLL_CFG1_CNT_INT(63);
+		pll_cfg2_init |= SUN8I_HDMI_PHY_PLL_CFG2_VCO_S(6) |
+				 SUN8I_HDMI_PHY_PLL_CFG2_S(7);
+		ana_cfg2_init |= SUN8I_HDMI_PHY_ANA_CFG2_REG_BIGSWCK |
+				 SUN8I_HDMI_PHY_ANA_CFG2_REG_BIGSW |
+				 SUN8I_HDMI_PHY_ANA_CFG2_REG_SLV(4);
+		ana_cfg3_init |= SUN8I_HDMI_PHY_ANA_CFG3_REG_AMPCK(9) |
+				 SUN8I_HDMI_PHY_ANA_CFG3_REG_AMP(13);
+	}
+
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_TXEN_MASK, 0);
+
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG, pll_cfg1_init);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_PLL_CFG2_REG,
+			   ~SUN8I_HDMI_PHY_PLL_CFG2_PREDIV_MSK, pll_cfg2_init);
+	usleep_range(10000, 15000);
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_PLL_CFG3_REG,
+		     SUN8I_HDMI_PHY_PLL_CFG3_SOUT_DIV2);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG,
+			   SUN8I_HDMI_PHY_PLL_CFG1_PLLEN,
+			   SUN8I_HDMI_PHY_PLL_CFG1_PLLEN);
+	msleep(100);
+
+	/* get B value */
+	regmap_read(phy->regs, SUN8I_HDMI_PHY_ANA_STS_REG, &val);
+	val = (val & SUN8I_HDMI_PHY_ANA_STS_B_OUT_MSK) >>
+		SUN8I_HDMI_PHY_ANA_STS_B_OUT_SHIFT;
+	val = min(val + b_offset, (u32)0x3f);
+
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG,
+			   SUN8I_HDMI_PHY_PLL_CFG1_REG_OD1 |
+			   SUN8I_HDMI_PHY_PLL_CFG1_REG_OD,
+			   SUN8I_HDMI_PHY_PLL_CFG1_REG_OD1 |
+			   SUN8I_HDMI_PHY_PLL_CFG1_REG_OD);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG,
+			   SUN8I_HDMI_PHY_PLL_CFG1_B_IN_MSK,
+			   val << SUN8I_HDMI_PHY_PLL_CFG1_B_IN_SHIFT);
+	msleep(100);
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG, ana_cfg1_end);
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_ANA_CFG2_REG, ana_cfg2_init);
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_ANA_CFG3_REG, ana_cfg3_init);
+
+	return 0;
+}
 
 static int sun8i_hdmi_phy_config(struct dw_hdmi *hdmi, void *data,
 				 struct drm_display_mode *mode)
@@ -91,6 +232,9 @@ static int sun8i_hdmi_phy_config(struct dw_hdmi *hdmi, void *data,
 			   SUN8I_HDMI_PHY_DBG_CTRL_POL_MASK,
 			   SUN8I_HDMI_PHY_DBG_CTRL_POL(val));
 
+	if (phy->variant->has_phy_clk)
+		clk_set_rate(phy->clk_phy, mode->crtc_clock * 1000);
+
 	return phy->variant->phy_config(hdmi, phy, mode->crtc_clock * 1000);
 };
 
@@ -104,6 +248,16 @@ static void sun8i_hdmi_phy_disable_a83t(struct dw_hdmi *hdmi,
 			   SUN8I_HDMI_PHY_REXT_CTRL_REXT_EN, 0);
 }
 
+static void sun8i_hdmi_phy_disable_h3(struct dw_hdmi *hdmi,
+				      struct sun8i_hdmi_phy *phy)
+{
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+		     SUN8I_HDMI_PHY_ANA_CFG1_LDOEN |
+		     SUN8I_HDMI_PHY_ANA_CFG1_ENVBS |
+		     SUN8I_HDMI_PHY_ANA_CFG1_ENBI);
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_PLL_CFG1_REG, 0);
+}
+
 static void sun8i_hdmi_phy_disable(struct dw_hdmi *hdmi, void *data)
 {
 	struct sun8i_hdmi_phy *phy = (struct sun8i_hdmi_phy *)data;
@@ -134,6 +288,78 @@ static void sun8i_hdmi_phy_init_a83t(struct sun8i_hdmi_phy *phy)
 			   SUN8I_HDMI_PHY_DBG_CTRL_ADDR(I2C_ADDR));
 }
 
+static void sun8i_hdmi_phy_init_h3(struct sun8i_hdmi_phy *phy)
+{
+	unsigned int val;
+
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG, 0);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENBI,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENBI);
+	udelay(5);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_TMDSCLK_EN,
+			   SUN8I_HDMI_PHY_ANA_CFG1_TMDSCLK_EN);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENVBS,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENVBS);
+	usleep_range(10, 20);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_LDOEN,
+			   SUN8I_HDMI_PHY_ANA_CFG1_LDOEN);
+	udelay(5);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_CKEN,
+			   SUN8I_HDMI_PHY_ANA_CFG1_CKEN);
+	usleep_range(40, 100);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENRCAL,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENRCAL);
+	usleep_range(100, 200);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENCALOG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENCALOG);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS0 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS1 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS2,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS0 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS1 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDS2);
+
+	/* wait for calibration to finish */
+	regmap_read_poll_timeout(phy->regs, SUN8I_HDMI_PHY_ANA_STS_REG, val,
+				 (val & SUN8I_HDMI_PHY_ANA_STS_RCALEND2D),
+				 100, 2000);
+
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDSCLK,
+			   SUN8I_HDMI_PHY_ANA_CFG1_ENP2S_TMDSCLK);
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG1_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS0 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS1 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS2 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDSCLK,
+			   SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS0 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS1 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDS2 |
+			   SUN8I_HDMI_PHY_ANA_CFG1_BIASEN_TMDSCLK);
+
+	/* enable DDC communication */
+	regmap_update_bits(phy->regs, SUN8I_HDMI_PHY_ANA_CFG3_REG,
+			   SUN8I_HDMI_PHY_ANA_CFG3_SCLEN |
+			   SUN8I_HDMI_PHY_ANA_CFG3_SDAEN,
+			   SUN8I_HDMI_PHY_ANA_CFG3_SCLEN |
+			   SUN8I_HDMI_PHY_ANA_CFG3_SDAEN);
+
+	/* set HW control of CEC pins */
+	regmap_write(phy->regs, SUN8I_HDMI_PHY_CEC_REG, 0);
+
+	/* read calibration data */
+	regmap_read(phy->regs, SUN8I_HDMI_PHY_ANA_STS_REG, &val);
+	phy->rcal = (val & SUN8I_HDMI_PHY_ANA_STS_RCAL_MASK) >> 2;
+}
+
 void sun8i_hdmi_phy_init(struct sun8i_hdmi_phy *phy)
 {
 	/* enable read access to HDMI controller */
@@ -156,7 +382,7 @@ static struct regmap_config sun8i_hdmi_phy_regmap_config = {
 	.reg_bits	= 32,
 	.val_bits	= 32,
 	.reg_stride	= 4,
-	.max_register	= SUN8I_HDMI_PHY_UNSCRAMBLE_REG,
+	.max_register	= SUN8I_HDMI_PHY_CEC_REG,
 	.name		= "phy"
 };
 
@@ -166,11 +392,22 @@ static const struct sun8i_hdmi_phy_variant sun8i_a83t_hdmi_phy = {
 	.phy_config = &sun8i_hdmi_phy_config_a83t,
 };
 
+static const struct sun8i_hdmi_phy_variant sun8i_h3_hdmi_phy = {
+	.has_phy_clk = true,
+	.phy_init = &sun8i_hdmi_phy_init_h3,
+	.phy_disable = &sun8i_hdmi_phy_disable_h3,
+	.phy_config = &sun8i_hdmi_phy_config_h3,
+};
+
 static const struct of_device_id sun8i_hdmi_phy_of_table[] = {
 	{
 		.compatible = "allwinner,sun8i-a83t-hdmi-phy",
 		.data = &sun8i_a83t_hdmi_phy,
 	},
+	{
+		.compatible = "allwinner,sun8i-h3-hdmi-phy",
+		.data = &sun8i_h3_hdmi_phy,
+	},
 	{ /* sentinel */ }
 };
 
@@ -227,11 +464,26 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi, struct device_node *node)
 		goto err_put_clk_bus;
 	}
 
+	if (phy->variant->has_phy_clk) {
+		phy->clk_pll0 = of_clk_get_by_name(node, "pll-0");
+		if (IS_ERR(phy->clk_pll0)) {
+			dev_err(dev, "Could not get pll-0 clock\n");
+			ret = PTR_ERR(phy->clk_pll0);
+			goto err_put_clk_mod;
+		}
+
+		ret = sun8i_phy_clk_create(phy, dev);
+		if (ret) {
+			dev_err(dev, "Couldn't create the PHY clock\n");
+			goto err_put_clk_pll0;
+		}
+	}
+
 	phy->rst_phy = of_reset_control_get_shared(node, "phy");
 	if (IS_ERR(phy->rst_phy)) {
 		dev_err(dev, "Could not get phy reset control\n");
 		ret = PTR_ERR(phy->rst_phy);
-		goto err_put_clk_mod;
+		goto err_put_clk_pll0;
 	}
 
 	ret = reset_control_deassert(phy->rst_phy);
@@ -262,6 +514,9 @@ int sun8i_hdmi_phy_probe(struct sun8i_dw_hdmi *hdmi, struct device_node *node)
 	reset_control_assert(phy->rst_phy);
 err_put_rst_phy:
 	reset_control_put(phy->rst_phy);
+err_put_clk_pll0:
+	if (phy->variant->has_phy_clk)
+		clk_put(phy->clk_pll0);
 err_put_clk_mod:
 	clk_put(phy->clk_mod);
 err_put_clk_bus:
@@ -281,6 +536,8 @@ void sun8i_hdmi_phy_remove(struct sun8i_dw_hdmi *hdmi)
 
 	reset_control_put(phy->rst_phy);
 
+	if (phy->variant->has_phy_clk)
+		clk_put(phy->clk_pll0);
 	clk_put(phy->clk_mod);
 	clk_put(phy->clk_bus);
 }
diff --git a/drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c
new file mode 100644
index 000000000000..3c34ec5ff4af
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Jernej Skrabec <jernej.skrabec@siol.net>
+ */
+
+#include <linux/clk-provider.h>
+
+#include "sun8i_dw_hdmi.h"
+
+struct sun8i_phy_clk {
+	struct clk_hw		hw;
+	struct sun8i_hdmi_phy	*phy;
+};
+
+static inline struct sun8i_phy_clk *hw_to_phy_clk(struct clk_hw *hw)
+{
+	return container_of(hw, struct sun8i_phy_clk, hw);
+}
+
+static int sun8i_phy_clk_determine_rate(struct clk_hw *hw,
+					struct clk_rate_request *req)
+{
+	unsigned long rate = req->rate;
+	unsigned long best_rate = 0;
+	struct clk_hw *parent;
+	int best_div = 1;
+	int i;
+
+	parent = clk_hw_get_parent(hw);
+
+	for (i = 1; i <= 16; i++) {
+		unsigned long ideal = rate * i;
+		unsigned long rounded;
+
+		rounded = clk_hw_round_rate(parent, ideal);
+
+		if (rounded == ideal) {
+			best_rate = rounded;
+			best_div = i;
+			break;
+		}
+
+		if (abs(rate - rounded) < abs(rate - best_rate / best_div)) {
+			best_rate = rounded;
+			best_div = i;
+		}
+	}
+
+	req->rate = best_rate / best_div;
+	req->best_parent_rate = best_rate;
+	req->best_parent_hw = parent;
+
+	return 0;
+}
+
+static unsigned long sun8i_phy_clk_recalc_rate(struct clk_hw *hw,
+					       unsigned long parent_rate)
+{
+	struct sun8i_phy_clk *priv = hw_to_phy_clk(hw);
+	u32 reg;
+
+	regmap_read(priv->phy->regs, SUN8I_HDMI_PHY_PLL_CFG2_REG, &reg);
+	reg = ((reg >> SUN8I_HDMI_PHY_PLL_CFG2_PREDIV_SHIFT) &
+		SUN8I_HDMI_PHY_PLL_CFG2_PREDIV_MSK) + 1;
+
+	return parent_rate / reg;
+}
+
+static int sun8i_phy_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long parent_rate)
+{
+	struct sun8i_phy_clk *priv = hw_to_phy_clk(hw);
+	unsigned long best_rate = 0;
+	u8 best_m = 0, m;
+
+	for (m = 1; m <= 16; m++) {
+		unsigned long tmp_rate = parent_rate / m;
+
+		if (tmp_rate > rate)
+			continue;
+
+		if (!best_rate ||
+		    (rate - tmp_rate) < (rate - best_rate)) {
+			best_rate = tmp_rate;
+			best_m = m;
+		}
+	}
+
+	regmap_update_bits(priv->phy->regs, SUN8I_HDMI_PHY_PLL_CFG2_REG,
+			   SUN8I_HDMI_PHY_PLL_CFG2_PREDIV_MSK,
+			   SUN8I_HDMI_PHY_PLL_CFG2_PREDIV(best_m));
+
+	return 0;
+}
+
+static const struct clk_ops sun8i_phy_clk_ops = {
+	.determine_rate	= sun8i_phy_clk_determine_rate,
+	.recalc_rate	= sun8i_phy_clk_recalc_rate,
+	.set_rate	= sun8i_phy_clk_set_rate,
+};
+
+int sun8i_phy_clk_create(struct sun8i_hdmi_phy *phy, struct device *dev)
+{
+	struct clk_init_data init;
+	struct sun8i_phy_clk *priv;
+	const char *parents[1];
+
+	parents[0] = __clk_get_name(phy->clk_pll0);
+	if (!parents[0])
+		return -ENODEV;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	init.name = "hdmi-phy-clk";
+	init.ops = &sun8i_phy_clk_ops;
+	init.parent_names = parents;
+	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_PARENT;
+
+	priv->phy = phy;
+	priv->hw.init = &init;
+
+	phy->clk_phy = devm_clk_register(dev, &priv->hw);
+	if (IS_ERR(phy->clk_phy))
+		return PTR_ERR(phy->clk_phy);
+
+	return 0;
+}
-- 
2.16.2