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

   1 /*
   2  * Copyright (c) 2012, 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 #include <linux/slab.h>
  19 #include <linux/err.h>
  20
  21 #include "clk.h"
  22
  23 static unsigned long clk_sync_source_recalc_rate(struct clk_hw *hw,
  24                                                  unsigned long parent_rate)
  25 {
  26         struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
  27
  28         return sync->rate;
  29 }
  30
  31 static long clk_sync_source_round_rate(struct clk_hw *hw, unsigned long rate,
  32                                        unsigned long *prate)
  33 {
  34         struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
  35
  36         if (rate > sync->max_rate)
  37                 return -EINVAL;
  38         else
  39                 return rate;
  40 }
  41
  42 static int clk_sync_source_set_rate(struct clk_hw *hw, unsigned long rate,
  43                                     unsigned long parent_rate)
  44 {
  45         struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
  46
  47         sync->rate = rate;
  48         return 0;
  49 }
  50
  51 const struct clk_ops tegra_clk_sync_source_ops = {
  52         .round_rate = clk_sync_source_round_rate,
  53         .set_rate = clk_sync_source_set_rate,
  54         .recalc_rate = clk_sync_source_recalc_rate,
  55 };
  56
  57 struct clk *tegra_clk_register_sync_source(const char *name,
  58                 unsigned long rate, unsigned long max_rate)
  59 {
  60         struct tegra_clk_sync_source *sync;
  61         struct clk_init_data init;
  62         struct clk *clk;
  63
  64         sync = kzalloc(sizeof(*sync), GFP_KERNEL);
  65         if (!sync) {
  66                 pr_err("%s: could not allocate sync source clk\n", __func__);
  67                 return ERR_PTR(-ENOMEM);
  68         }
  69
  70         sync->rate = rate;
  71         sync->max_rate = max_rate;
  72
  73         init.ops = &tegra_clk_sync_source_ops;
  74         init.name = name;
  75         init.flags = CLK_IS_ROOT;
  76         init.parent_names = NULL;
  77         init.num_parents = 0;
  78
  79         /* Data in .init is copied by clk_register(), so stack variable OK */
  80         sync->hw.init = &init;
  81
  82         clk = clk_register(NULL, &sync->hw);
  83         if (IS_ERR(clk))
  84                 kfree(sync);
  85
  86         return clk;
  87 }