1// SPDX-License-Identifier: (GPL-2.0 OR MIT)
  2/*
  3 * Copyright (c) 2018 BayLibre, SAS.
  4 * Author: Jerome Brunet <jbrunet@baylibre.com>
  5 */
  6
  7#include <linux/clk-provider.h>
  8#include <linux/module.h>
  9
 10#include "clk-regmap.h"
 11#include "clk-phase.h"
 12
 13#define phase_step(_width) (360 / (1 << (_width)))
 14
 15static inline struct meson_clk_phase_data *
 16meson_clk_phase_data(struct clk_regmap *clk)
 17{
 18	return (struct meson_clk_phase_data *)clk->data;
 19}
 20
 21static int meson_clk_degrees_from_val(unsigned int val, unsigned int width)
 22{
 23	return phase_step(width) * val;
 24}
 25
 26static unsigned int meson_clk_degrees_to_val(int degrees, unsigned int width)
 27{
 28	unsigned int val = DIV_ROUND_CLOSEST(degrees, phase_step(width));
 29
 30	/*
 31	 * This last calculation is here for cases when degrees is rounded
 32	 * to 360, in which case val == (1 << width).
 33	 */
 34	return val % (1 << width);
 35}
 36
 37static int meson_clk_phase_get_phase(struct clk_hw *hw)
 38{
 39	struct clk_regmap *clk = to_clk_regmap(hw);
 40	struct meson_clk_phase_data *phase = meson_clk_phase_data(clk);
 41	unsigned int val;
 42
 43	val = meson_parm_read(clk->map, &phase->ph);
 44
 45	return meson_clk_degrees_from_val(val, phase->ph.width);
 46}
 47
 48static int meson_clk_phase_set_phase(struct clk_hw *hw, int degrees)
 49{
 50	struct clk_regmap *clk = to_clk_regmap(hw);
 51	struct meson_clk_phase_data *phase = meson_clk_phase_data(clk);
 52	unsigned int val;
 53
 54	val = meson_clk_degrees_to_val(degrees, phase->ph.width);
 55	meson_parm_write(clk->map, &phase->ph, val);
 56
 57	return 0;
 58}
 59
 60const struct clk_ops meson_clk_phase_ops = {
 61	.get_phase	= meson_clk_phase_get_phase,
 62	.set_phase	= meson_clk_phase_set_phase,
 63};
 64EXPORT_SYMBOL_GPL(meson_clk_phase_ops);
 65
 66/*
 67 * This is a special clock for the audio controller.
 68 * The phase of mst_sclk clock output can be controlled independently
 69 * for the outside world (ph0), the tdmout (ph1) and tdmin (ph2).
 70 * Controlling these 3 phases as just one makes things simpler and
 71 * give the same clock view to all the element on the i2s bus.
 72 * If necessary, we can still control the phase in the tdm block
 73 * which makes these independent control redundant.
 74 */
 75static inline struct meson_clk_triphase_data *
 76meson_clk_triphase_data(struct clk_regmap *clk)
 77{
 78	return (struct meson_clk_triphase_data *)clk->data;
 79}
 80
 81static void meson_clk_triphase_sync(struct clk_hw *hw)
 82{
 83	struct clk_regmap *clk = to_clk_regmap(hw);
 84	struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
 85	unsigned int val;
 86
 87	/* Get phase 0 and sync it to phase 1 and 2 */
 88	val = meson_parm_read(clk->map, &tph->ph0);
 89	meson_parm_write(clk->map, &tph->ph1, val);
 90	meson_parm_write(clk->map, &tph->ph2, val);
 91}
 92
 93static int meson_clk_triphase_get_phase(struct clk_hw *hw)
 94{
 95	struct clk_regmap *clk = to_clk_regmap(hw);
 96	struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
 97	unsigned int val;
 98
 99	/* Phase are in sync, reading phase 0 is enough */
100	val = meson_parm_read(clk->map, &tph->ph0);
101
102	return meson_clk_degrees_from_val(val, tph->ph0.width);
103}
104
105static int meson_clk_triphase_set_phase(struct clk_hw *hw, int degrees)
106{
107	struct clk_regmap *clk = to_clk_regmap(hw);
108	struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
109	unsigned int val;
110
111	val = meson_clk_degrees_to_val(degrees, tph->ph0.width);
112	meson_parm_write(clk->map, &tph->ph0, val);
113	meson_parm_write(clk->map, &tph->ph1, val);
114	meson_parm_write(clk->map, &tph->ph2, val);
115
116	return 0;
117}
118
119const struct clk_ops meson_clk_triphase_ops = {
120	.init		= meson_clk_triphase_sync,
121	.get_phase	= meson_clk_triphase_get_phase,
122	.set_phase	= meson_clk_triphase_set_phase,
123};
124EXPORT_SYMBOL_GPL(meson_clk_triphase_ops);
125
126MODULE_DESCRIPTION("Amlogic phase driver");
127MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
128MODULE_LICENSE("GPL v2");