drivers/clk/meson/clk-phase.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.h"
   9
  10 #define phase_step(_width) (360 / (1 << (_width)))
  11
  12 static inline struct meson_clk_phase_data *
  13 meson_clk_phase_data(struct clk_regmap *clk)
  14 {
  15         return (struct meson_clk_phase_data *)clk->data;
  16 }
  17
  18 int meson_clk_degrees_from_val(unsigned int val, unsigned int width)
  19 {
  20         return phase_step(width) * val;
  21 }
  22 EXPORT_SYMBOL_GPL(meson_clk_degrees_from_val);
  23
  24 unsigned int meson_clk_degrees_to_val(int degrees, unsigned int width)
  25 {
  26         unsigned int val = DIV_ROUND_CLOSEST(degrees, phase_step(width));
  27
  28         /*
  29          * This last calculation is here for cases when degrees is rounded
  30          * to 360, in which case val == (1 << width).
  31          */
  32         return val % (1 << width);
  33 }
  34 EXPORT_SYMBOL_GPL(meson_clk_degrees_to_val);
  35
  36 static int meson_clk_phase_get_phase(struct clk_hw *hw)
  37 {
  38         struct clk_regmap *clk = to_clk_regmap(hw);
  39         struct meson_clk_phase_data *phase = meson_clk_phase_data(clk);
  40         unsigned int val;
  41
  42         val = meson_parm_read(clk->map, &phase->ph);
  43
  44         return meson_clk_degrees_from_val(val, phase->ph.width);
  45 }
  46
  47 static int meson_clk_phase_set_phase(struct clk_hw *hw, int degrees)
  48 {
  49         struct clk_regmap *clk = to_clk_regmap(hw);
  50         struct meson_clk_phase_data *phase = meson_clk_phase_data(clk);
  51         unsigned int val;
  52
  53         val = meson_clk_degrees_to_val(degrees, phase->ph.width);
  54         meson_parm_write(clk->map, &phase->ph, val);
  55
  56         return 0;
  57 }
  58
  59 const struct clk_ops meson_clk_phase_ops = {
  60         .get_phase      = meson_clk_phase_get_phase,
  61         .set_phase      = meson_clk_phase_set_phase,
  62 };
  63 EXPORT_SYMBOL_GPL(meson_clk_phase_ops);