[mirror_ubuntu-eoan-kernel.git] / drivers / gpu / drm / sun4i / sun4i_hdmi_tmds_clk.c

/*
 * 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_hdmi.h"

struct sun4i_tmds {
	struct clk_hw		hw;
	struct sun4i_hdmi	*hdmi;

	u8			div_offset;
};

static inline struct sun4i_tmds *hw_to_tmds(struct clk_hw *hw)
{
	return container_of(hw, struct sun4i_tmds, hw);
}


static unsigned long sun4i_tmds_calc_divider(unsigned long rate,
					     unsigned long parent_rate,
					     u8 div_offset,
					     u8 *div,
					     bool *half)
{
	unsigned long best_rate = 0;
	u8 best_m = 0, m;
	bool is_double;

	for (m = div_offset ?: 1; m < (16 + div_offset); m++) {
		u8 d;

		for (d = 1; d < 3; d++) {
			unsigned long tmp_rate;

			tmp_rate = parent_rate / m / d;

			if (tmp_rate > rate)
				continue;

			if (!best_rate ||
			    (rate - tmp_rate) < (rate - best_rate)) {
				best_rate = tmp_rate;
				best_m = m;
				is_double = d;
			}
		}
	}

	if (div && half) {
		*div = best_m;
		*half = is_double;
	}

	return best_rate;
}


static int sun4i_tmds_determine_rate(struct clk_hw *hw,
				     struct clk_rate_request *req)
{
	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	struct clk_hw *parent = NULL;
	unsigned long best_parent = 0;
	unsigned long rate = req->rate;
	int best_div = 1, best_half = 1;
	int i, j, p;

	/*
	 * We only consider PLL3, since the TCON is very likely to be
	 * clocked from it, and to have the same rate than our HDMI
	 * clock, so we should not need to do anything.
	 */

	for (p = 0; p < clk_hw_get_num_parents(hw); p++) {
		parent = clk_hw_get_parent_by_index(hw, p);
		if (!parent)
			continue;

		for (i = 1; i < 3; i++) {
			for (j = tmds->div_offset ?: 1;
			     j < (16 + tmds->div_offset); j++) {
				unsigned long ideal = rate * i * j;
				unsigned long rounded;

				rounded = clk_hw_round_rate(parent, ideal);

				if (rounded == ideal) {
					best_parent = rounded;
					best_half = i;
					best_div = j;
					goto out;
				}

				if (!best_parent || abs(rate - rounded / i) <
				    abs(rate - best_parent / best_div)) {
					best_parent = rounded;
					best_div = j;
				}
			}
		}
	}

	if (!parent)
		return -EINVAL;

out:
	req->rate = best_parent / best_half / best_div;
	req->best_parent_rate = best_parent;
	req->best_parent_hw = parent;

	return 0;
}

static unsigned long sun4i_tmds_recalc_rate(struct clk_hw *hw,
					    unsigned long parent_rate)
{
	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	u32 reg;

	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
	if (reg & SUN4I_HDMI_PAD_CTRL1_HALVE_CLK)
		parent_rate /= 2;

	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
	reg = ((reg >> 4) & 0xf) + tmds->div_offset;
	if (!reg)
		reg = 1;

	return parent_rate / reg;
}

static int sun4i_tmds_set_rate(struct clk_hw *hw, unsigned long rate,
			       unsigned long parent_rate)
{
	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	bool half;
	u32 reg;
	u8 div;

	sun4i_tmds_calc_divider(rate, parent_rate, tmds->div_offset,
				&div, &half);

	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
	reg &= ~SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
	if (half)
		reg |= SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
	writel(reg, tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);

	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
	reg &= ~SUN4I_HDMI_PLL_CTRL_DIV_MASK;
	writel(reg | SUN4I_HDMI_PLL_CTRL_DIV(div - tmds->div_offset),
	       tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);

	return 0;
}

static u8 sun4i_tmds_get_parent(struct clk_hw *hw)
{
	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	u32 reg;

	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);
	return ((reg & SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_MASK) >>
		SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_SHIFT);
}

static int sun4i_tmds_set_parent(struct clk_hw *hw, u8 index)
{
	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	u32 reg;

	if (index > 1)
		return -EINVAL;

	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);
	reg &= ~SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_MASK;
	writel(reg | SUN4I_HDMI_PLL_DBG0_TMDS_PARENT(index),
	       tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);

	return 0;
}

static const struct clk_ops sun4i_tmds_ops = {
	.determine_rate	= sun4i_tmds_determine_rate,
	.recalc_rate	= sun4i_tmds_recalc_rate,
	.set_rate	= sun4i_tmds_set_rate,

	.get_parent	= sun4i_tmds_get_parent,
	.set_parent	= sun4i_tmds_set_parent,
};

int sun4i_tmds_create(struct sun4i_hdmi *hdmi)
{
	struct clk_init_data init;
	struct sun4i_tmds *tmds;
	const char *parents[2];

	parents[0] = __clk_get_name(hdmi->pll0_clk);
	if (!parents[0])
		return -ENODEV;

	parents[1] = __clk_get_name(hdmi->pll1_clk);
	if (!parents[1])
		return -ENODEV;

	tmds = devm_kzalloc(hdmi->dev, sizeof(*tmds), GFP_KERNEL);
	if (!tmds)
		return -ENOMEM;

	init.name = "hdmi-tmds";
	init.ops = &sun4i_tmds_ops;
	init.parent_names = parents;
	init.num_parents = 2;
	init.flags = CLK_SET_RATE_PARENT;

	tmds->hdmi = hdmi;
	tmds->hw.init = &init;
	tmds->div_offset = hdmi->variant->tmds_clk_div_offset;

	hdmi->tmds_clk = devm_clk_register(hdmi->dev, &tmds->hw);
	if (IS_ERR(hdmi->tmds_clk))
		return PTR_ERR(hdmi->tmds_clk);

	return 0;
}
Commit	Line	Data
9c568101 MR	1	/*
	2	* Copyright (C) 2016 Free Electrons
	3	* Copyright (C) 2016 NextThing Co
	4	*
	5	* Maxime Ripard <maxime.ripard@free-electrons.com>
	6	*
	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.
	11	*/
	12
	13	#include <linux/clk-provider.h>
	14
9c568101 MR	15	#include "sun4i_hdmi.h"
	16
	17	struct sun4i_tmds {
	18	struct clk_hw hw;
	19	struct sun4i_hdmi *hdmi;
939d749a CYT	20
939d749a CYT	21	u8 div_offset;
9c568101 MR	22	};
	23
	24	static inline struct sun4i_tmds hw_to_tmds(struct clk_hw hw)
	25	{
	26	return container_of(hw, struct sun4i_tmds, hw);
	27	}
	28
	29
	30	static unsigned long sun4i_tmds_calc_divider(unsigned long rate,
	31	unsigned long parent_rate,
939d749a	32	u8 div_offset,
9c568101 MR	33	u8 *div,
	34	bool *half)
	35	{
	36	unsigned long best_rate = 0;
	37	u8 best_m = 0, m;
	38	bool is_double;
	39
939d749a	40	for (m = div_offset ?: 1; m < (16 + div_offset); m++) {
9c568101 MR	41	u8 d;
	42
	43	for (d = 1; d < 3; d++) {
	44	unsigned long tmp_rate;
	45
	46	tmp_rate = parent_rate / m / d;
	47
	48	if (tmp_rate > rate)
	49	continue;
	50
	51	if (!best_rate \|\|
	52	(rate - tmp_rate) < (rate - best_rate)) {
	53	best_rate = tmp_rate;
	54	best_m = m;
	55	is_double = d;
	56	}
	57	}
	58	}
	59
	60	if (div && half) {
	61	*div = best_m;
	62	*half = is_double;
	63	}
	64
	65	return best_rate;
	66	}
	67
	68
	69	static int sun4i_tmds_determine_rate(struct clk_hw *hw,
	70	struct clk_rate_request *req)
	71	{
939d749a	72	struct sun4i_tmds *tmds = hw_to_tmds(hw);
cc67ae90	73	struct clk_hw *parent = NULL;
9c568101 MR	74	unsigned long best_parent = 0;
	75	unsigned long rate = req->rate;
	76	int best_div = 1, best_half = 1;
cc67ae90	77	int i, j, p;
9c568101 MR	78
	79	/*
	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.
	83	*/
	84
cc67ae90 CYT	85	for (p = 0; p < clk_hw_get_num_parents(hw); p++) {
	86	parent = clk_hw_get_parent_by_index(hw, p);
	87	if (!parent)
	88	continue;
	89
	90	for (i = 1; i < 3; i++) {
939d749a CYT	91	for (j = tmds->div_offset ?: 1;
939d749a CYT	92	j < (16 + tmds->div_offset); j++) {
cc67ae90 CYT	93	unsigned long ideal = rate * i * j;
	94	unsigned long rounded;
	95
	96	rounded = clk_hw_round_rate(parent, ideal);
	97
	98	if (rounded == ideal) {
	99	best_parent = rounded;
	100	best_half = i;
	101	best_div = j;
	102	goto out;
	103	}
	104
111f4c33	105	if (!best_parent \|\| abs(rate - rounded / i) <
cc67ae90 CYT	106	abs(rate - best_parent / best_div)) {
cc67ae90 CYT	107	best_parent = rounded;
58faae28	108	best_div = j;
cc67ae90	109	}
9c568101 MR	110	}
	111	}
	112	}
	113
cc67ae90 CYT	114	if (!parent)
	115	return -EINVAL;
	116
9c568101 MR	117	out:
	118	req->rate = best_parent / best_half / best_div;
	119	req->best_parent_rate = best_parent;
	120	req->best_parent_hw = parent;
	121
	122	return 0;
	123	}
	124
	125	static unsigned long sun4i_tmds_recalc_rate(struct clk_hw *hw,
	126	unsigned long parent_rate)
	127	{
	128	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	129	u32 reg;
	130
	131	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
	132	if (reg & SUN4I_HDMI_PAD_CTRL1_HALVE_CLK)
	133	parent_rate /= 2;
	134
	135	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
939d749a	136	reg = ((reg >> 4) & 0xf) + tmds->div_offset;
9c568101 MR	137	if (!reg)
	138	reg = 1;
	139
	140	return parent_rate / reg;
	141	}
	142
	143	static int sun4i_tmds_set_rate(struct clk_hw *hw, unsigned long rate,
	144	unsigned long parent_rate)
	145	{
	146	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	147	bool half;
	148	u32 reg;
	149	u8 div;
	150
939d749a CYT	151	sun4i_tmds_calc_divider(rate, parent_rate, tmds->div_offset,
939d749a CYT	152	&div, &half);
9c568101 MR	153
	154	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
	155	reg &= ~SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
	156	if (half)
	157	reg \|= SUN4I_HDMI_PAD_CTRL1_HALVE_CLK;
	158	writel(reg, tmds->hdmi->base + SUN4I_HDMI_PAD_CTRL1_REG);
	159
	160	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
	161	reg &= ~SUN4I_HDMI_PLL_CTRL_DIV_MASK;
939d749a	162	writel(reg \| SUN4I_HDMI_PLL_CTRL_DIV(div - tmds->div_offset),
9c568101 MR	163	tmds->hdmi->base + SUN4I_HDMI_PLL_CTRL_REG);
	164
	165	return 0;
	166	}
	167
	168	static u8 sun4i_tmds_get_parent(struct clk_hw *hw)
	169	{
	170	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	171	u32 reg;
	172
	173	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);
	174	return ((reg & SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_MASK) >>
	175	SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_SHIFT);
	176	}
	177
	178	static int sun4i_tmds_set_parent(struct clk_hw *hw, u8 index)
	179	{
	180	struct sun4i_tmds *tmds = hw_to_tmds(hw);
	181	u32 reg;
	182
	183	if (index > 1)
	184	return -EINVAL;
	185
	186	reg = readl(tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);
	187	reg &= ~SUN4I_HDMI_PLL_DBG0_TMDS_PARENT_MASK;
	188	writel(reg \| SUN4I_HDMI_PLL_DBG0_TMDS_PARENT(index),
	189	tmds->hdmi->base + SUN4I_HDMI_PLL_DBG0_REG);
	190
	191	return 0;
	192	}
	193
	194	static const struct clk_ops sun4i_tmds_ops = {
	195	.determine_rate = sun4i_tmds_determine_rate,
	196	.recalc_rate = sun4i_tmds_recalc_rate,
	197	.set_rate = sun4i_tmds_set_rate,
	198
	199	.get_parent = sun4i_tmds_get_parent,
	200	.set_parent = sun4i_tmds_set_parent,
	201	};
	202
	203	int sun4i_tmds_create(struct sun4i_hdmi *hdmi)
	204	{
	205	struct clk_init_data init;
	206	struct sun4i_tmds *tmds;
	207	const char *parents[2];
	208
	209	parents[0] = __clk_get_name(hdmi->pll0_clk);
	210	if (!parents[0])
	211	return -ENODEV;
	212
	213	parents[1] = __clk_get_name(hdmi->pll1_clk);
	214	if (!parents[1])
	215	return -ENODEV;
	216
	217	tmds = devm_kzalloc(hdmi->dev, sizeof(*tmds), GFP_KERNEL);
	218	if (!tmds)
	219	return -ENOMEM;
	220
	221	init.name = "hdmi-tmds";
	222	init.ops = &sun4i_tmds_ops;
	223	init.parent_names = parents;
	224	init.num_parents = 2;
	225	init.flags = CLK_SET_RATE_PARENT;
	226
227	tmds->hdmi = hdmi;
228	tmds->hw.init = &init;
939d749a	229	tmds->div_offset = hdmi->variant->tmds_clk_div_offset;
9c568101 MR	230
	231	hdmi->tmds_clk = devm_clk_register(hdmi->dev, &tmds->hw);
	232	if (IS_ERR(hdmi->tmds_clk))
	233	return PTR_ERR(hdmi->tmds_clk);
	234
	235	return 0;
	236	}