LXR linux/drivers/clk/meson/clk-triphase.c

   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 "clkc-audio.h"
   9
  10/*
  11 * This is a special clock for the audio controller.
  12 * The phase of mst_sclk clock output can be controlled independently
  13 * for the outside world (ph0), the tdmout (ph1) and tdmin (ph2).
  14 * Controlling these 3 phases as just one makes things simpler and
  15 * give the same clock view to all the element on the i2s bus.
  16 * If necessary, we can still control the phase in the tdm block
  17 * which makes these independent control redundant.
  18 */
  19static inline struct meson_clk_triphase_data *
  20meson_clk_triphase_data(struct clk_regmap *clk)
  21{
  22        return (struct meson_clk_triphase_data *)clk->data;
  23}
  24
  25static void meson_clk_triphase_sync(struct clk_hw *hw)
  26{
  27        struct clk_regmap *clk = to_clk_regmap(hw);
  28        struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
  29        unsigned int val;
  30
  31        /* Get phase 0 and sync it to phase 1 and 2 */
  32        val = meson_parm_read(clk->map, &tph->ph0);
  33        meson_parm_write(clk->map, &tph->ph1, val);
  34        meson_parm_write(clk->map, &tph->ph2, val);
  35}
  36
  37static int meson_clk_triphase_get_phase(struct clk_hw *hw)
  38{
  39        struct clk_regmap *clk = to_clk_regmap(hw);
  40        struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
  41        unsigned int val;
  42
  43        /* Phase are in sync, reading phase 0 is enough */
  44        val = meson_parm_read(clk->map, &tph->ph0);
  45
  46        return meson_clk_degrees_from_val(val, tph->ph0.width);
  47}
  48
  49static int meson_clk_triphase_set_phase(struct clk_hw *hw, int degrees)
  50{
  51        struct clk_regmap *clk = to_clk_regmap(hw);
  52        struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
  53        unsigned int val;
  54
  55        val = meson_clk_degrees_to_val(degrees, tph->ph0.width);
  56        meson_parm_write(clk->map, &tph->ph0, val);
  57        meson_parm_write(clk->map, &tph->ph1, val);
  58        meson_parm_write(clk->map, &tph->ph2, val);
  59
  60        return 0;
  61}
  62
  63const struct clk_ops meson_clk_triphase_ops = {
  64        .init           = meson_clk_triphase_sync,
  65        .get_phase      = meson_clk_triphase_get_phase,
  66        .set_phase      = meson_clk_triphase_set_phase,
  67};
  68EXPORT_SYMBOL_GPL(meson_clk_triphase_ops);
  69