1 files changed, 132 insertions, 0 deletions
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..faea449812f8
--- /dev/null
+++ b/drivers/gpu/drm/sun4i/sun8i_hdmi_phy_clk.c
@@ -0,0 +1,132 @@
+// 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 (!best_rate ||
+		    abs(rate - rounded / i) <
+		    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;
+}