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 } 88