clk/tegra/clk-audio-sync.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
0004  */
0005
0006 #include <linux/clk-provider.h>
0007 #include <linux/slab.h>
0008 #include <linux/err.h>
0009
0010 #include "clk.h"
0011
0012 static unsigned long clk_sync_source_recalc_rate(struct clk_hw *hw,
0013                          unsigned long parent_rate)
0014 {
0015     struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
0016
0017     return sync->rate;
0018 }
0019
0020 static long clk_sync_source_round_rate(struct clk_hw *hw, unsigned long rate,
0021                        unsigned long *prate)
0022 {
0023     struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
0024
0025     if (rate > sync->max_rate)
0026         return -EINVAL;
0027     else
0028         return rate;
0029 }
0030
0031 static int clk_sync_source_set_rate(struct clk_hw *hw, unsigned long rate,
0032                     unsigned long parent_rate)
0033 {
0034     struct tegra_clk_sync_source *sync = to_clk_sync_source(hw);
0035
0036     sync->rate = rate;
0037     return 0;
0038 }
0039
0040 const struct clk_ops tegra_clk_sync_source_ops = {
0041     .round_rate = clk_sync_source_round_rate,
0042     .set_rate = clk_sync_source_set_rate,
0043     .recalc_rate = clk_sync_source_recalc_rate,
0044 };
0045
0046 struct clk *tegra_clk_register_sync_source(const char *name,
0047                        unsigned long max_rate)
0048 {
0049     struct tegra_clk_sync_source *sync;
0050     struct clk_init_data init;
0051     struct clk *clk;
0052
0053     sync = kzalloc(sizeof(*sync), GFP_KERNEL);
0054     if (!sync) {
0055         pr_err("%s: could not allocate sync source clk\n", __func__);
0056         return ERR_PTR(-ENOMEM);
0057     }
0058
0059     sync->max_rate = max_rate;
0060
0061     init.ops = &tegra_clk_sync_source_ops;
0062     init.name = name;
0063     init.flags = 0;
0064     init.parent_names = NULL;
0065     init.num_parents = 0;
0066
0067     /* Data in .init is copied by clk_register(), so stack variable OK */
0068     sync->hw.init = &init;
0069
0070     clk = clk_register(NULL, &sync->hw);
0071     if (IS_ERR(clk))
0072         kfree(sync);
0073
0074     return clk;
0075 }