drivers/clk/at91/clk-slow.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * drivers/clk/at91/clk-slow.c
   4  *
   5  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
   6  */
   7
   8 #include <linux/clk-provider.h>
   9 #include <linux/clkdev.h>
  10 #include <linux/clk/at91_pmc.h>
  11 #include <linux/of.h>
  12 #include <linux/mfd/syscon.h>
  13 #include <linux/regmap.h>
  14
  15 #include "pmc.h"
  16
  17 struct clk_sam9260_slow {
  18         struct clk_hw hw;
  19         struct regmap *regmap;
  20 };
  21
  22 #define to_clk_sam9260_slow(hw) container_of(hw, struct clk_sam9260_slow, hw)
  23
  24 static u8 clk_sam9260_slow_get_parent(struct clk_hw *hw)
  25 {
  26         struct clk_sam9260_slow *slowck = to_clk_sam9260_slow(hw);
  27         unsigned int status;
  28
  29         regmap_read(slowck->regmap, AT91_PMC_SR, &status);
  30
  31         return status & AT91_PMC_OSCSEL ? 1 : 0;
  32 }
  33
  34 static const struct clk_ops sam9260_slow_ops = {
  35         .get_parent = clk_sam9260_slow_get_parent,
  36 };
  37
  38 struct clk_hw * __init
  39 at91_clk_register_sam9260_slow(struct regmap *regmap,
  40                                const char *name,
  41                                const char **parent_names,
  42                                int num_parents)
  43 {
  44         struct clk_sam9260_slow *slowck;
  45         struct clk_hw *hw;
  46         struct clk_init_data init;
  47         int ret;
  48
  49         if (!name)
  50                 return ERR_PTR(-EINVAL);
  51
  52         if (!parent_names || !num_parents)
  53                 return ERR_PTR(-EINVAL);
  54
  55         slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
  56         if (!slowck)
  57                 return ERR_PTR(-ENOMEM);
  58
  59         init.name = name;
  60         init.ops = &sam9260_slow_ops;
  61         init.parent_names = parent_names;
  62         init.num_parents = num_parents;
  63         init.flags = 0;
  64
  65         slowck->hw.init = &init;
  66         slowck->regmap = regmap;
  67
  68         hw = &slowck->hw;
  69         ret = clk_hw_register(NULL, &slowck->hw);
  70         if (ret) {
  71                 kfree(slowck);
  72                 hw = ERR_PTR(ret);
  73         }
  74
  75         return hw;
  76 }