drm/rockchip: inno_hdmi: Add variant support

In preparation to support RK3128's integration of the controller, this
patch adds a simple variant implementation. They mainly differ in the phy
configuration required, so those are part of the match_data. The values
have been taken from downstream. The pixelclocks in there are meant to be
max-inclusive.
Signed-off-by: Alex Bee <knaerzche@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20231222174220.55249-24-knaerzche@gmail.com

drivers/gpu/drm/rockchip/inno_hdmi.c

@@ -25,6 +25,17 @@
 
 #include "inno_hdmi.h"
 
+struct inno_hdmi_phy_config {
+	unsigned long pixelclock;
+	u8 pre_emphasis;
+	u8 voltage_level_control;
+};
+
+struct inno_hdmi_variant {
+	struct inno_hdmi_phy_config *phy_configs;
+	struct inno_hdmi_phy_config *default_phy_config;
+};
+
 struct inno_hdmi_i2c {
 	struct i2c_adapter adap;
 
@@ -46,6 +57,8 @@ struct inno_hdmi {
 
 	struct inno_hdmi_i2c *i2c;
 	struct i2c_adapter *ddc;
+
+	const struct inno_hdmi_variant *variant;
 };
 
 struct inno_hdmi_connector_state {
@@ -112,6 +125,30 @@ static const char coeff_csc[][24] = {
 	},
 };
 
+static struct inno_hdmi_phy_config rk3036_hdmi_phy_configs[] = {
+	{  74250000, 0x3f, 0xbb },
+	{ 165000000, 0x6f, 0xbb },
+	{      ~0UL, 0x00, 0x00 }
+};
+
+static int inno_hdmi_find_phy_config(struct inno_hdmi *hdmi,
+				     unsigned long pixelclk)
+{
+	const struct inno_hdmi_phy_config *phy_configs =
+						hdmi->variant->phy_configs;
+	int i;
+
+	for (i = 0; phy_configs[i].pixelclock != ~0UL; i++) {
+		if (pixelclk <= phy_configs[i].pixelclock)
+			return i;
+	}
+
+	DRM_DEV_DEBUG(hdmi->dev, "No phy configuration for pixelclock %lu\n",
+		      pixelclk);
+
+	return -EINVAL;
+}
+
 static inline u8 hdmi_readb(struct inno_hdmi *hdmi, u16 offset)
 {
 	return readl_relaxed(hdmi->regs + (offset) * 0x04);
@@ -163,12 +200,25 @@ static void inno_hdmi_standby(struct inno_hdmi *hdmi)
 	hdmi_writeb(hdmi, HDMI_PHY_SYS_CTL, 0x15);
 };
 
-static void inno_hdmi_power_up(struct inno_hdmi *hdmi)
+static void inno_hdmi_power_up(struct inno_hdmi *hdmi,
+			       unsigned long mpixelclock)
 {
+	struct inno_hdmi_phy_config *phy_config;
+	int ret = inno_hdmi_find_phy_config(hdmi, mpixelclock);
+
+	if (ret < 0) {
+		phy_config = hdmi->variant->default_phy_config;
+		DRM_DEV_ERROR(hdmi->dev,
+			      "Using default phy configuration for TMDS rate %lu",
+			      mpixelclock);
+	} else {
+		phy_config = &hdmi->variant->phy_configs[ret];
+	}
+
 	inno_hdmi_sys_power(hdmi, false);
 
-	hdmi_writeb(hdmi, HDMI_PHY_PRE_EMPHASIS, 0x6f);
-	hdmi_writeb(hdmi, HDMI_PHY_DRIVER, 0xbb);
+	hdmi_writeb(hdmi, HDMI_PHY_PRE_EMPHASIS, phy_config->pre_emphasis);
+	hdmi_writeb(hdmi, HDMI_PHY_DRIVER, phy_config->voltage_level_control);
 	hdmi_writeb(hdmi, HDMI_PHY_SYS_CTL, 0x15);
 	hdmi_writeb(hdmi, HDMI_PHY_SYS_CTL, 0x14);
 	hdmi_writeb(hdmi, HDMI_PHY_SYS_CTL, 0x10);
@@ -405,6 +455,7 @@ static int inno_hdmi_setup(struct inno_hdmi *hdmi,
 			   struct drm_display_mode *mode)
 {
 	struct drm_display_info *display = &hdmi->connector.display_info;
+	unsigned long mpixelclock = mode->clock * 1000;
 
 	/* Mute video and audio output */
 	hdmi_modb(hdmi, HDMI_AV_MUTE, m_AUDIO_MUTE | m_VIDEO_BLACK,
@@ -427,13 +478,13 @@ static int inno_hdmi_setup(struct inno_hdmi *hdmi,
 	 * DCLK_LCDC, so we need to init the TMDS rate to mode pixel
 	 * clock rate, and reconfigure the DDC clock.
 	 */
-	inno_hdmi_i2c_init(hdmi, mode->clock * 1000);
+	inno_hdmi_i2c_init(hdmi, mpixelclock);
 
 	/* Unmute video and audio output */
 	hdmi_modb(hdmi, HDMI_AV_MUTE, m_AUDIO_MUTE | m_VIDEO_BLACK,
 		  v_AUDIO_MUTE(0) | v_VIDEO_MUTE(0));
 
-	inno_hdmi_power_up(hdmi);
+	inno_hdmi_power_up(hdmi, mpixelclock);
 
 	return 0;
 }
@@ -825,6 +876,7 @@ static int inno_hdmi_bind(struct device *dev, struct device *master,
 	struct platform_device *pdev = to_platform_device(dev);
 	struct drm_device *drm = data;
 	struct inno_hdmi *hdmi;
+	const struct inno_hdmi_variant *variant;
 	int irq;
 	int ret;
 
@@ -834,6 +886,12 @@ static int inno_hdmi_bind(struct device *dev, struct device *master,
 
 	hdmi->dev = dev;
 
+	variant = of_device_get_match_data(hdmi->dev);
+	if (!variant)
+		return -EINVAL;
+
+	hdmi->variant = variant;
+
 	hdmi->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(hdmi->regs))
 		return PTR_ERR(hdmi->regs);
@@ -927,8 +985,14 @@ static void inno_hdmi_remove(struct platform_device *pdev)
 	component_del(&pdev->dev, &inno_hdmi_ops);
 }
 
+static const struct inno_hdmi_variant rk3036_inno_hdmi_variant = {
+	.phy_configs = rk3036_hdmi_phy_configs,
+	.default_phy_config = &rk3036_hdmi_phy_configs[1],
+};
+
 static const struct of_device_id inno_hdmi_dt_ids[] = {
 	{ .compatible = "rockchip,rk3036-inno-hdmi",
+	  .data = &rk3036_inno_hdmi_variant,
 	},
 	{},
 };