2 * Copyright (C) 2016 Free Electrons
3 * Copyright (C) 2016 NextThing Co
5 * Maxime Ripard <maxime.ripard@free-electrons.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
13 #include <linux/clk-provider.h>
15 #include "sun4i_hdmi.h"
19 struct sun4i_hdmi *hdmi;
24 static inline struct sun4i_tmds *hw_to_tmds(struct clk_hw *hw)
26 return container_of(hw, struct sun4i_tmds, hw);
30 static unsigned long sun4i_tmds_calc_divider(unsigned long rate,
31 unsigned long parent_rate,
36 unsigned long best_rate = 0;
40 for (m = div_offset ?: 1; m < (16 + div_offset); m++) {
43 for (d = 1; d < 3; d++) {
44 unsigned long tmp_rate;
46 tmp_rate = parent_rate / m / d;
52 (rate - tmp_rate) < (rate - best_rate)) {
55 is_double = (d == 2) ? true : false;
69 static int sun4i_tmds_determine_rate(struct clk_hw *hw,
70 struct clk_rate_request *req)
72 struct sun4i_tmds *tmds = hw_to_tmds(hw);
73 struct clk_hw *parent = NULL;
74 unsigned long best_parent = 0;
75 unsigned long rate = req->rate;
76 int best_div = 1, best_half = 1;
80 * We only consider PLL3, since the TCON is very likely to be
81 * clocked from it, and to have the same rate than our HDMI
82 * clock, so we should not need to do anything.
85 for (p = 0; p < clk_hw_get_num_parents(hw); p++) {
86 parent = clk_hw_get_parent_by_index(hw, p);
90 for (i = 1; i < 3; i++) {
91 for (j = tmds->div_offset ?: 1;
92 j < (16 + tmds->div_offset); j++) {
93 unsigned long ideal = rate * i * j;
94 unsigned long rounded;
96 rounded = clk_hw_round_rate(parent, ideal);
98 if (rounded == ideal) {
99 best_parent = rounded;
106 abs(rate - rounded / i / j) <
107 abs(rate - best_parent / best_half /
109 best_parent = rounded;
121 req->rate = best_parent / best_half / best_div;
122 req->best_parent_rate = best_parent;
123 req->best_parent_hw = parent;
128 static unsigned long sun4i_tmds_recalc_rate(struct clk_hw *hw,
129 unsigned long parent_rate)
131 struct sun4i_tmds *tmds = hw_to_tmds(hw);
134 reg = readl(tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
135 if (reg & SUN4I_HDMI_PAD_CTRL1_HALVE_CLK)
138 reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
139 reg = ((reg >> 4) & 0xf) + tmds->div_offset;
143 return parent_rate / reg;
146 static int sun4i_tmds_set_rate(struct clk_hw *hw, unsigned long rate,
147 unsigned long parent_rate)
149 struct sun4i_tmds *tmds = hw_to_tmds(hw);
154 sun4i_tmds_calc_divider(rate, parent_rate, tmds->div_offset,
157 reg = readl(tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
158 reg &= ~SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
160 reg |= SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
161 writel(reg, tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
163 reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
164 reg &= ~SUN4I_HDMI_PLL_CTRL_DIV_MASK;
165 writel(reg | SUN4I_HDMI_PLL_CTRL_DIV(div - tmds->div_offset),
166 tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
171 static u8 sun4i_tmds_get_parent(struct clk_hw *hw)
173 struct sun4i_tmds *tmds = hw_to_tmds(hw);
176 reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);
177 return ((reg & SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_MASK) >>
178 SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_SHIFT);
181 static int sun4i_tmds_set_parent(struct clk_hw *hw, u8 index)
183 struct sun4i_tmds *tmds = hw_to_tmds(hw);
189 reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);
190 reg &= ~SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_MASK;
191 writel(reg | SUN4I_HDMI_PLL_DBG0_TMDS_PARENT(index),
192 tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);
197 static const struct clk_ops sun4i_tmds_ops = {
198 .determine_rate = sun4i_tmds_determine_rate,
199 .recalc_rate = sun4i_tmds_recalc_rate,
200 .set_rate = sun4i_tmds_set_rate,
202 .get_parent = sun4i_tmds_get_parent,
203 .set_parent = sun4i_tmds_set_parent,
206 int sun4i_tmds_create(struct sun4i_hdmi *hdmi)
208 struct clk_init_data init;
209 struct sun4i_tmds *tmds;
210 const char *parents[2];
212 parents[0] = __clk_get_name(hdmi->pll0_clk);
216 parents[1] = __clk_get_name(hdmi->pll1_clk);
220 tmds = devm_kzalloc(hdmi->dev, sizeof(*tmds), GFP_KERNEL);
224 init.name = "hdmi-tmds";
225 init.ops = &sun4i_tmds_ops;
226 init.parent_names = parents;
227 init.num_parents = 2;
228 init.flags = CLK_SET_RATE_PARENT;
231 tmds->hw.init = &init;
232 tmds->div_offset = hdmi->variant->tmds_clk_div_offset;
234 hdmi->tmds_clk = devm_clk_register(hdmi->dev, &tmds->hw);
235 if (IS_ERR(hdmi->tmds_clk))
236 return PTR_ERR(hdmi->tmds_clk);