drivers/clk/sprd/mux.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Spreadtrum multiplexer clock driver
   4 //
   5 // Copyright (C) 2017 Spreadtrum, Inc.
   6 // Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
   7
   8 #include <linux/clk.h>
   9 #include <linux/clk-provider.h>
  10 #include <linux/regmap.h>
  11
  12 #include "mux.h"
  13
  14 u8 sprd_mux_helper_get_parent(const struct sprd_clk_common *common,
  15                               const struct sprd_mux_ssel *mux)
  16 {
  17         unsigned int reg;
  18         u8 parent;
  19         int num_parents;
  20         int i;
  21
  22         regmap_read(common->regmap, common->reg, &reg);
  23         parent = reg >> mux->shift;
  24         parent &= (1 << mux->width) - 1;
  25
  26         if (!mux->table)
  27                 return parent;
  28
  29         num_parents = clk_hw_get_num_parents(&common->hw);
  30
  31         for (i = 0; i < num_parents - 1; i++)
  32                 if (parent >= mux->table[i] && parent < mux->table[i + 1])
  33                         return i;
  34
  35         return num_parents - 1;
  36 }
  37 EXPORT_SYMBOL_GPL(sprd_mux_helper_get_parent);
  38
  39 static u8 sprd_mux_get_parent(struct clk_hw *hw)
  40 {
  41         struct sprd_mux *cm = hw_to_sprd_mux(hw);
  42
  43         return sprd_mux_helper_get_parent(&cm->common, &cm->mux);
  44 }
  45
  46 int sprd_mux_helper_set_parent(const struct sprd_clk_common *common,
  47                                const struct sprd_mux_ssel *mux,
  48                                u8 index)
  49 {
  50         unsigned int reg;
  51
  52         if (mux->table)
  53                 index = mux->table[index];
  54
  55         regmap_read(common->regmap, common->reg, &reg);
  56         reg &= ~GENMASK(mux->width + mux->shift - 1, mux->shift);
  57         regmap_write(common->regmap, common->reg,
  58                           reg | (index << mux->shift));
  59
  60         return 0;
  61 }
  62 EXPORT_SYMBOL_GPL(sprd_mux_helper_set_parent);
  63
  64 static int sprd_mux_set_parent(struct clk_hw *hw, u8 index)
  65 {
  66         struct sprd_mux *cm = hw_to_sprd_mux(hw);
  67
  68         return sprd_mux_helper_set_parent(&cm->common, &cm->mux, index);
  69 }
  70
  71 const struct clk_ops sprd_mux_ops = {
  72         .get_parent = sprd_mux_get_parent,
  73         .set_parent = sprd_mux_set_parent,
  74         .determine_rate = __clk_mux_determine_rate,
  75 };
  76 EXPORT_SYMBOL_GPL(sprd_mux_ops);