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// 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 >> 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;
}
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