drivers/clk/actions/owl-mux.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 //
   3 // OWL mux clock driver
   4 //
   5 // Copyright (c) 2014 Actions Semi Inc.
   6 // Author: David Liu <liuwei@actions-semi.com>
   7 //
   8 // Copyright (c) 2018 Linaro Ltd.
   9 // Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/regmap.h>
  13
  14 #include "owl-mux.h"
  15
  16 u8 owl_mux_helper_get_parent(const struct owl_clk_common *common,
  17                              const struct owl_mux_hw *mux_hw)
  18 {
  19         u32 reg;
  20         u8 parent;
  21
  22         regmap_read(common->regmap, mux_hw->reg, &reg);
  23         parent = reg >> mux_hw->shift;
  24         parent &= BIT(mux_hw->width) - 1;
  25
  26         return parent;
  27 }
  28
  29 static u8 owl_mux_get_parent(struct clk_hw *hw)
  30 {
  31         struct owl_mux *mux = hw_to_owl_mux(hw);
  32
  33         return owl_mux_helper_get_parent(&mux->common, &mux->mux_hw);
  34 }
  35
  36 int owl_mux_helper_set_parent(const struct owl_clk_common *common,
  37                               struct owl_mux_hw *mux_hw, u8 index)
  38 {
  39         u32 reg;
  40
  41         regmap_read(common->regmap, mux_hw->reg, &reg);
  42         reg &= ~GENMASK(mux_hw->width + mux_hw->shift - 1, mux_hw->shift);
  43         regmap_write(common->regmap, mux_hw->reg,
  44                         reg | (index << mux_hw->shift));
  45
  46         return 0;
  47 }
  48
  49 static int owl_mux_set_parent(struct clk_hw *hw, u8 index)
  50 {
  51         struct owl_mux *mux = hw_to_owl_mux(hw);
  52
  53         return owl_mux_helper_set_parent(&mux->common, &mux->mux_hw, index);
  54 }
  55
  56 const struct clk_ops owl_mux_ops = {
  57         .get_parent = owl_mux_get_parent,
  58         .set_parent = owl_mux_set_parent,
  59         .determine_rate = __clk_mux_determine_rate,
  60 };