drivers/clk/tegra/clk-periph-fixed.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015, NVIDIA CORPORATION.  All rights reserved.
   4  */
   5
   6 #include <linux/clk-provider.h>
   7 #include <linux/io.h>
   8
   9 #include "clk.h"
  10
  11 static inline struct tegra_clk_periph_fixed *
  12 to_tegra_clk_periph_fixed(struct clk_hw *hw)
  13 {
  14         return container_of(hw, struct tegra_clk_periph_fixed, hw);
  15 }
  16
  17 static int tegra_clk_periph_fixed_is_enabled(struct clk_hw *hw)
  18 {
  19         struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
  20         u32 mask = 1 << (fixed->num % 32), value;
  21
  22         value = readl(fixed->base + fixed->regs->enb_reg);
  23         if (value & mask) {
  24                 value = readl(fixed->base + fixed->regs->rst_reg);
  25                 if ((value & mask) == 0)
  26                         return 1;
  27         }
  28
  29         return 0;
  30 }
  31
  32 static int tegra_clk_periph_fixed_enable(struct clk_hw *hw)
  33 {
  34         struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
  35         u32 mask = 1 << (fixed->num % 32);
  36
  37         writel(mask, fixed->base + fixed->regs->enb_set_reg);
  38
  39         return 0;
  40 }
  41
  42 static void tegra_clk_periph_fixed_disable(struct clk_hw *hw)
  43 {
  44         struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
  45         u32 mask = 1 << (fixed->num % 32);
  46
  47         writel(mask, fixed->base + fixed->regs->enb_clr_reg);
  48 }
  49
  50 static unsigned long
  51 tegra_clk_periph_fixed_recalc_rate(struct clk_hw *hw,
  52                                    unsigned long parent_rate)
  53 {
  54         struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
  55         unsigned long long rate;
  56
  57         rate = (unsigned long long)parent_rate * fixed->mul;
  58         do_div(rate, fixed->div);
  59
  60         return (unsigned long)rate;
  61 }
  62
  63 static const struct clk_ops tegra_clk_periph_fixed_ops = {
  64         .is_enabled = tegra_clk_periph_fixed_is_enabled,
  65         .enable = tegra_clk_periph_fixed_enable,
  66         .disable = tegra_clk_periph_fixed_disable,
  67         .recalc_rate = tegra_clk_periph_fixed_recalc_rate,
  68 };
  69
  70 struct clk *tegra_clk_register_periph_fixed(const char *name,
  71                                             const char *parent,
  72                                             unsigned long flags,
  73                                             void __iomem *base,
  74                                             unsigned int mul,
  75                                             unsigned int div,
  76                                             unsigned int num)
  77 {
  78         const struct tegra_clk_periph_regs *regs;
  79         struct tegra_clk_periph_fixed *fixed;
  80         struct clk_init_data init;
  81         struct clk *clk;
  82
  83         regs = get_reg_bank(num);
  84         if (!regs)
  85                 return ERR_PTR(-EINVAL);
  86
  87         fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
  88         if (!fixed)
  89                 return ERR_PTR(-ENOMEM);
  90
  91         init.name = name;
  92         init.flags = flags;
  93         init.parent_names = parent ? &parent : NULL;
  94         init.num_parents = parent ? 1 : 0;
  95         init.ops = &tegra_clk_periph_fixed_ops;
  96
  97         fixed->base = base;
  98         fixed->regs = regs;
  99         fixed->mul = mul;
 100         fixed->div = div;
 101         fixed->num = num;
 102
 103         fixed->hw.init = &init;
 104
 105         clk = clk_register(NULL, &fixed->hw);
 106         if (IS_ERR(clk))
 107                 kfree(fixed);
 108
 109         return clk;
 110 }