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/*
* Copyright (C) 2016 Free Electrons
* Copyright (C) 2016 NextThing Co
*
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*/
#include <linux/clk-provider.h>
#include "sun4i_tcon.h"
#include "sun4i_hdmi.h"
struct sun4i_ddc {
struct clk_hw hw;
struct sun4i_hdmi *hdmi;
};
static inline struct sun4i_ddc *hw_to_ddc(struct clk_hw *hw)
{
return container_of(hw, struct sun4i_ddc, hw);
}
static unsigned long sun4i_ddc_calc_divider(unsigned long rate,
unsigned long parent_rate,
u8 *m, u8 *n)
{
unsigned long best_rate = 0;
u8 best_m = 0, best_n = 0, _m, _n;
for (_m = 0; _m < 8; _m++) {
for (_n = 0; _n < 8; _n++) {
unsigned long tmp_rate;
tmp_rate = (((parent_rate / 2) / 10) >> _n) / (_m + 1);
if (tmp_rate > rate)
continue;
if (abs(rate - tmp_rate) < abs(rate - best_rate)) {
best_rate = tmp_rate;
best_m = _m;
best_n = _n;
}
}
}
if (m && n) {
*m = best_m;
*n = best_n;
}
return best_rate;
}
static long sun4i_ddc_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
return sun4i_ddc_calc_divider(rate, *prate, NULL, NULL);
}
static unsigned long sun4i_ddc_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct sun4i_ddc *ddc = hw_to_ddc(hw);
u32 reg;
u8 m, n;
reg = readl(ddc->hdmi->base + SUN4I_HDMI_DDC_CLK_REG);
m = (reg >> 3) & 0x7;
n = reg & 0x7;
return (((parent_rate / 2) / 10) >> n) / (m + 1);
}
static int sun4i_ddc_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct sun4i_ddc *ddc = hw_to_ddc(hw);
u8 div_m, div_n;
sun4i_ddc_calc_divider(rate, parent_rate, &div_m, &div_n);
writel(SUN4I_HDMI_DDC_CLK_M(div_m) | SUN4I_HDMI_DDC_CLK_N(div_n),
ddc->hdmi->base + SUN4I_HDMI_DDC_CLK_REG);
return 0;
}
static const struct clk_ops sun4i_ddc_ops = {
.recalc_rate = sun4i_ddc_recalc_rate,
.round_rate = sun4i_ddc_round_rate,
.set_rate = sun4i_ddc_set_rate,
};
int sun4i_ddc_create(struct sun4i_hdmi *hdmi, struct clk *parent)
{
struct clk_init_data init;
struct sun4i_ddc *ddc;
const char *parent_name;
parent_name = __clk_get_name(parent);
if (!parent_name)
return -ENODEV;
ddc = devm_kzalloc(hdmi->dev, sizeof(*ddc), GFP_KERNEL);
if (!ddc)
return -ENOMEM;
init.name = "hdmi-ddc";
init.ops = &sun4i_ddc_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
ddc->hdmi = hdmi;
ddc->hw.init = &init;
hdmi->ddc_clk = devm_clk_register(hdmi->dev, &ddc->hw);
if (IS_ERR(hdmi->ddc_clk))
return PTR_ERR(hdmi->ddc_clk);
return 0;
}
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