LXR linux/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
  11static inline struct tegra_clk_periph_fixed *
  12to_tegra_clk_periph_fixed(struct clk_hw *hw)
  13{
  14        return container_of(hw, struct tegra_clk_periph_fixed, hw);
  15}
  16
  17static 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
  32static 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
  42static 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
  50static unsigned long
  51tegra_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
  63static 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
  70struct 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}
 111