linux/drivers/clk/tegra/clk-audio-sync.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   4 */
   5
   6#include <linux/clk-provider.h>
   7#include <linux/slab.h>
   8#include <linux/err.h>
   9
  10#include "clk.h"
  11
  12static unsigned long clk_sync_source_recalc_rate(struct clk_hw *hw,
  13                                                 unsigned long parent_rate)
  14{
  15        struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
  16
  17        return sync->rate;
  18}
  19
  20static long clk_sync_source_round_rate(struct clk_hw *hw, unsigned long rate,
  21                                       unsigned long *prate)
  22{
  23        struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
  24
  25        if (rate > sync->max_rate)
  26                return -EINVAL;
  27        else
  28                return rate;
  29}
  30
  31static int clk_sync_source_set_rate(struct clk_hw *hw, unsigned long rate,
  32                                    unsigned long parent_rate)
  33{
  34        struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
  35
  36        sync->rate = rate;
  37        return 0;
  38}
  39
  40const struct clk_ops tegra_clk_sync_source_ops = {
  41        .round_rate = clk_sync_source_round_rate,
  42        .set_rate = clk_sync_source_set_rate,
  43        .recalc_rate = clk_sync_source_recalc_rate,
  44};
  45
  46struct clk *tegra_clk_register_sync_source(const char *name,
  47                                           unsigned long max_rate)
  48{
  49        struct tegra_clk_sync_source *sync;
  50        struct clk_init_data init;
  51        struct clk *clk;
  52
  53        sync = kzalloc(sizeof(*sync), GFP_KERNEL);
  54        if (!sync) {
  55                pr_err("%s: could not allocate sync source clk\n", __func__);
  56                return ERR_PTR(-ENOMEM);
  57        }
  58
  59        sync->max_rate = max_rate;
  60
  61        init.ops = &tegra_clk_sync_source_ops;
  62        init.name = name;
  63        init.flags = 0;
  64        init.parent_names = NULL;
  65        init.num_parents = 0;
  66
  67        /* Data in .init is copied by clk_register(), so stack variable OK */
  68        sync->hw.init = &init;
  69
  70        clk = clk_register(NULL, &sync->hw);
  71        if (IS_ERR(clk))
  72                kfree(sync);
  73
  74        return clk;
  75}
  76