kernel/drivers/clk/qcom/clk-regmap-divider.c

   1 /*
   2  * Copyright (c) 2014, The Linux Foundation. All rights reserved.
   3  *
   4  * This software is licensed under the terms of the GNU General Public
   5  * License version 2, as published by the Free Software Foundation, and
   6  * may be copied, distributed, and modified under those terms.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/bitops.h>
  16 #include <linux/regmap.h>
  17 #include <linux/export.h>
  18
  19 #include "clk-regmap-divider.h"
  20
  21 static inline struct clk_regmap_div *to_clk_regmap_div(struct clk_hw *hw)
  22 {
  23         return container_of(to_clk_regmap(hw), struct clk_regmap_div, clkr);
  24 }
  25
  26 static long div_round_rate(struct clk_hw *hw, unsigned long rate,
  27                            unsigned long *prate)
  28 {
  29         struct clk_regmap_div *divider = to_clk_regmap_div(hw);
  30
  31         return divider_round_rate(hw, rate, prate, NULL, divider->width,
  32                                   CLK_DIVIDER_ROUND_CLOSEST);
  33 }
  34
  35 static int div_set_rate(struct clk_hw *hw, unsigned long rate,
  36                         unsigned long parent_rate)
  37 {
  38         struct clk_regmap_div *divider = to_clk_regmap_div(hw);
  39         struct clk_regmap *clkr = &divider->clkr;
  40         u32 div;
  41
  42         div = divider_get_val(rate, parent_rate, NULL, divider->width,
  43                               CLK_DIVIDER_ROUND_CLOSEST);
  44
  45         return regmap_update_bits(clkr->regmap, divider->reg,
  46                                   (BIT(divider->width) - 1) << divider->shift,
  47                                   div << divider->shift);
  48 }
  49
  50 static unsigned long div_recalc_rate(struct clk_hw *hw,
  51                                      unsigned long parent_rate)
  52 {
  53         struct clk_regmap_div *divider = to_clk_regmap_div(hw);
  54         struct clk_regmap *clkr = &divider->clkr;
  55         u32 div;
  56
  57         regmap_read(clkr->regmap, divider->reg, &div);
  58         div >>= divider->shift;
  59         div &= BIT(divider->width) - 1;
  60
  61         return divider_recalc_rate(hw, parent_rate, div, NULL,
  62                                    CLK_DIVIDER_ROUND_CLOSEST);
  63 }
  64
  65 const struct clk_ops clk_regmap_div_ops = {
  66         .round_rate = div_round_rate,
  67         .set_rate = div_set_rate,
  68         .recalc_rate = div_recalc_rate,
  69 };
  70 EXPORT_SYMBOL_GPL(clk_regmap_div_ops);