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

   1/*
   2 * Copyright (c) 2015, NVIDIA CORPORATION.  All rights reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms and conditions of the GNU General Public License,
   6 * version 2, as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope it will be useful, but WITHOUT
   9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11 * more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15 */
  16
  17#include <linux/clk-provider.h>
  18
  19#include "clk.h"
  20
  21static inline struct tegra_clk_periph_fixed *
  22to_tegra_clk_periph_fixed(struct clk_hw *hw)
  23{
  24        return container_of(hw, struct tegra_clk_periph_fixed, hw);
  25}
  26
  27static int tegra_clk_periph_fixed_is_enabled(struct clk_hw *hw)
  28{
  29        struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
  30        u32 mask = 1 << (fixed->num % 32), value;
  31
  32        value = readl(fixed->base + fixed->regs->enb_reg);
  33        if (value & mask) {
  34                value = readl(fixed->base + fixed->regs->rst_reg);
  35                if ((value & mask) == 0)
  36                        return 1;
  37        }
  38
  39        return 0;
  40}
  41
  42static int tegra_clk_periph_fixed_enable(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_set_reg);
  48
  49        return 0;
  50}
  51
  52static void tegra_clk_periph_fixed_disable(struct clk_hw *hw)
  53{
  54        struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
  55        u32 mask = 1 << (fixed->num % 32);
  56
  57        writel(mask, fixed->base + fixed->regs->enb_clr_reg);
  58}
  59
  60static unsigned long
  61tegra_clk_periph_fixed_recalc_rate(struct clk_hw *hw,
  62                                   unsigned long parent_rate)
  63{
  64        struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
  65        unsigned long long rate;
  66
  67        rate = (unsigned long long)parent_rate * fixed->mul;
  68        do_div(rate, fixed->div);
  69
  70        return (unsigned long)rate;
  71}
  72
  73static const struct clk_ops tegra_clk_periph_fixed_ops = {
  74        .is_enabled = tegra_clk_periph_fixed_is_enabled,
  75        .enable = tegra_clk_periph_fixed_enable,
  76        .disable = tegra_clk_periph_fixed_disable,
  77        .recalc_rate = tegra_clk_periph_fixed_recalc_rate,
  78};
  79
  80struct clk *tegra_clk_register_periph_fixed(const char *name,
  81                                            const char *parent,
  82                                            unsigned long flags,
  83                                            void __iomem *base,
  84                                            unsigned int mul,
  85                                            unsigned int div,
  86                                            unsigned int num)
  87{
  88        const struct tegra_clk_periph_regs *regs;
  89        struct tegra_clk_periph_fixed *fixed;
  90        struct clk_init_data init;
  91        struct clk *clk;
  92
  93        regs = get_reg_bank(num);
  94        if (!regs)
  95                return ERR_PTR(-EINVAL);
  96
  97        fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
  98        if (!fixed)
  99                return ERR_PTR(-ENOMEM);
 100
 101        init.name = name;
 102        init.flags = flags;
 103        init.parent_names = parent ? &parent : NULL;
 104        init.num_parents = parent ? 1 : 0;
 105        init.ops = &tegra_clk_periph_fixed_ops;
 106
 107        fixed->base = base;
 108        fixed->regs = regs;
 109        fixed->mul = mul;
 110        fixed->div = div;
 111        fixed->num = num;
 112
 113        fixed->hw.init = &init;
 114
 115        clk = clk_register(NULL, &fixed->hw);
 116        if (IS_ERR(clk))
 117                kfree(fixed);
 118
 119        return clk;
 120}
 121