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Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
142 lines
3 KiB
C
142 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2016 Free Electrons
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* Copyright (C) 2016 NextThing Co
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*
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* Maxime Ripard <maxime.ripard@free-electrons.com>
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*/
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#include <linux/clk-provider.h>
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#include <linux/regmap.h>
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#include "sun4i_hdmi.h"
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struct sun4i_ddc {
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struct clk_hw hw;
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struct sun4i_hdmi *hdmi;
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struct regmap_field *reg;
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u8 pre_div;
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u8 m_offset;
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};
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static inline struct sun4i_ddc *hw_to_ddc(struct clk_hw *hw)
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{
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return container_of(hw, struct sun4i_ddc, hw);
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}
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static unsigned long sun4i_ddc_calc_divider(unsigned long rate,
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unsigned long parent_rate,
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const u8 pre_div,
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const u8 m_offset,
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u8 *m, u8 *n)
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{
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unsigned long best_rate = 0;
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u8 best_m = 0, best_n = 0, _m, _n;
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for (_m = 0; _m < 8; _m++) {
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for (_n = 0; _n < 8; _n++) {
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unsigned long tmp_rate;
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tmp_rate = (((parent_rate / pre_div) / 10) >> _n) /
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(_m + m_offset);
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if (tmp_rate > rate)
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continue;
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if (abs(rate - tmp_rate) < abs(rate - best_rate)) {
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best_rate = tmp_rate;
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best_m = _m;
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best_n = _n;
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}
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}
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}
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if (m && n) {
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*m = best_m;
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*n = best_n;
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}
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return best_rate;
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}
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static long sun4i_ddc_round_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long *prate)
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{
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struct sun4i_ddc *ddc = hw_to_ddc(hw);
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return sun4i_ddc_calc_divider(rate, *prate, ddc->pre_div,
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ddc->m_offset, NULL, NULL);
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}
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static unsigned long sun4i_ddc_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct sun4i_ddc *ddc = hw_to_ddc(hw);
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unsigned int reg;
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u8 m, n;
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regmap_field_read(ddc->reg, ®);
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m = (reg >> 3) & 0xf;
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n = reg & 0x7;
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return (((parent_rate / ddc->pre_div) / 10) >> n) /
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(m + ddc->m_offset);
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}
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static int sun4i_ddc_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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struct sun4i_ddc *ddc = hw_to_ddc(hw);
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u8 div_m, div_n;
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sun4i_ddc_calc_divider(rate, parent_rate, ddc->pre_div,
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ddc->m_offset, &div_m, &div_n);
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regmap_field_write(ddc->reg,
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SUN4I_HDMI_DDC_CLK_M(div_m) |
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SUN4I_HDMI_DDC_CLK_N(div_n));
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return 0;
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}
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static const struct clk_ops sun4i_ddc_ops = {
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.recalc_rate = sun4i_ddc_recalc_rate,
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.round_rate = sun4i_ddc_round_rate,
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.set_rate = sun4i_ddc_set_rate,
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};
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int sun4i_ddc_create(struct sun4i_hdmi *hdmi, struct clk *parent)
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{
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struct clk_init_data init;
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struct sun4i_ddc *ddc;
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const char *parent_name;
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parent_name = __clk_get_name(parent);
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if (!parent_name)
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return -ENODEV;
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ddc = devm_kzalloc(hdmi->dev, sizeof(*ddc), GFP_KERNEL);
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if (!ddc)
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return -ENOMEM;
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ddc->reg = devm_regmap_field_alloc(hdmi->dev, hdmi->regmap,
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hdmi->variant->ddc_clk_reg);
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if (IS_ERR(ddc->reg))
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return PTR_ERR(ddc->reg);
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init.name = "hdmi-ddc";
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init.ops = &sun4i_ddc_ops;
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init.parent_names = &parent_name;
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init.num_parents = 1;
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ddc->hdmi = hdmi;
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ddc->hw.init = &init;
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ddc->pre_div = hdmi->variant->ddc_clk_pre_divider;
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ddc->m_offset = hdmi->variant->ddc_clk_m_offset;
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hdmi->ddc_clk = devm_clk_register(hdmi->dev, &ddc->hw);
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if (IS_ERR(hdmi->ddc_clk))
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return PTR_ERR(hdmi->ddc_clk);
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return 0;
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}
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