drivers/clk/tegra/clk-audio-sync.c

   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
  12 static 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
  20 static 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
  31 static 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
  40 const 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
  46 struct 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 }