| 1 | /* |
| 2 | * Copyright (c) 2013 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.h> |
| 18 | #include <linux/clk-provider.h> |
| 19 | #include <linux/err.h> |
| 20 | #include <linux/slab.h> |
| 21 | |
| 22 | #define to_clk_composite(_hw) container_of(_hw, struct clk_composite, hw) |
| 23 | |
| 24 | static u8 clk_composite_get_parent(struct clk_hw *hw) |
| 25 | { |
| 26 | struct clk_composite *composite = to_clk_composite(hw); |
| 27 | const struct clk_ops *mux_ops = composite->mux_ops; |
| 28 | struct clk_hw *mux_hw = composite->mux_hw; |
| 29 | |
| 30 | __clk_hw_set_clk(mux_hw, hw); |
| 31 | |
| 32 | return mux_ops->get_parent(mux_hw); |
| 33 | } |
| 34 | |
| 35 | static int clk_composite_set_parent(struct clk_hw *hw, u8 index) |
| 36 | { |
| 37 | struct clk_composite *composite = to_clk_composite(hw); |
| 38 | const struct clk_ops *mux_ops = composite->mux_ops; |
| 39 | struct clk_hw *mux_hw = composite->mux_hw; |
| 40 | |
| 41 | __clk_hw_set_clk(mux_hw, hw); |
| 42 | |
| 43 | return mux_ops->set_parent(mux_hw, index); |
| 44 | } |
| 45 | |
| 46 | static unsigned long clk_composite_recalc_rate(struct clk_hw *hw, |
| 47 | unsigned long parent_rate) |
| 48 | { |
| 49 | struct clk_composite *composite = to_clk_composite(hw); |
| 50 | const struct clk_ops *rate_ops = composite->rate_ops; |
| 51 | struct clk_hw *rate_hw = composite->rate_hw; |
| 52 | |
| 53 | __clk_hw_set_clk(rate_hw, hw); |
| 54 | |
| 55 | return rate_ops->recalc_rate(rate_hw, parent_rate); |
| 56 | } |
| 57 | |
| 58 | static int clk_composite_determine_rate(struct clk_hw *hw, |
| 59 | struct clk_rate_request *req) |
| 60 | { |
| 61 | struct clk_composite *composite = to_clk_composite(hw); |
| 62 | const struct clk_ops *rate_ops = composite->rate_ops; |
| 63 | const struct clk_ops *mux_ops = composite->mux_ops; |
| 64 | struct clk_hw *rate_hw = composite->rate_hw; |
| 65 | struct clk_hw *mux_hw = composite->mux_hw; |
| 66 | struct clk_hw *parent; |
| 67 | unsigned long parent_rate; |
| 68 | long tmp_rate, best_rate = 0; |
| 69 | unsigned long rate_diff; |
| 70 | unsigned long best_rate_diff = ULONG_MAX; |
| 71 | long rate; |
| 72 | int i; |
| 73 | |
| 74 | if (rate_hw && rate_ops && rate_ops->determine_rate) { |
| 75 | __clk_hw_set_clk(rate_hw, hw); |
| 76 | return rate_ops->determine_rate(rate_hw, req); |
| 77 | } else if (rate_hw && rate_ops && rate_ops->round_rate && |
| 78 | mux_hw && mux_ops && mux_ops->set_parent) { |
| 79 | req->best_parent_hw = NULL; |
| 80 | |
| 81 | if (clk_hw_get_flags(hw) & CLK_SET_RATE_NO_REPARENT) { |
| 82 | parent = clk_hw_get_parent(mux_hw); |
| 83 | req->best_parent_hw = parent; |
| 84 | req->best_parent_rate = clk_hw_get_rate(parent); |
| 85 | |
| 86 | rate = rate_ops->round_rate(rate_hw, req->rate, |
| 87 | &req->best_parent_rate); |
| 88 | if (rate < 0) |
| 89 | return rate; |
| 90 | |
| 91 | req->rate = rate; |
| 92 | return 0; |
| 93 | } |
| 94 | |
| 95 | for (i = 0; i < clk_hw_get_num_parents(mux_hw); i++) { |
| 96 | parent = clk_hw_get_parent_by_index(mux_hw, i); |
| 97 | if (!parent) |
| 98 | continue; |
| 99 | |
| 100 | parent_rate = clk_hw_get_rate(parent); |
| 101 | |
| 102 | tmp_rate = rate_ops->round_rate(rate_hw, req->rate, |
| 103 | &parent_rate); |
| 104 | if (tmp_rate < 0) |
| 105 | continue; |
| 106 | |
| 107 | rate_diff = abs(req->rate - tmp_rate); |
| 108 | |
| 109 | if (!rate_diff || !req->best_parent_hw |
| 110 | || best_rate_diff > rate_diff) { |
| 111 | req->best_parent_hw = parent; |
| 112 | req->best_parent_rate = parent_rate; |
| 113 | best_rate_diff = rate_diff; |
| 114 | best_rate = tmp_rate; |
| 115 | } |
| 116 | |
| 117 | if (!rate_diff) |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | req->rate = best_rate; |
| 122 | return 0; |
| 123 | } else if (mux_hw && mux_ops && mux_ops->determine_rate) { |
| 124 | __clk_hw_set_clk(mux_hw, hw); |
| 125 | return mux_ops->determine_rate(mux_hw, req); |
| 126 | } else { |
| 127 | pr_err("clk: clk_composite_determine_rate function called, but no mux or rate callback set!\n"); |
| 128 | return -EINVAL; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | static long clk_composite_round_rate(struct clk_hw *hw, unsigned long rate, |
| 133 | unsigned long *prate) |
| 134 | { |
| 135 | struct clk_composite *composite = to_clk_composite(hw); |
| 136 | const struct clk_ops *rate_ops = composite->rate_ops; |
| 137 | struct clk_hw *rate_hw = composite->rate_hw; |
| 138 | |
| 139 | __clk_hw_set_clk(rate_hw, hw); |
| 140 | |
| 141 | return rate_ops->round_rate(rate_hw, rate, prate); |
| 142 | } |
| 143 | |
| 144 | static int clk_composite_set_rate(struct clk_hw *hw, unsigned long rate, |
| 145 | unsigned long parent_rate) |
| 146 | { |
| 147 | struct clk_composite *composite = to_clk_composite(hw); |
| 148 | const struct clk_ops *rate_ops = composite->rate_ops; |
| 149 | struct clk_hw *rate_hw = composite->rate_hw; |
| 150 | |
| 151 | __clk_hw_set_clk(rate_hw, hw); |
| 152 | |
| 153 | return rate_ops->set_rate(rate_hw, rate, parent_rate); |
| 154 | } |
| 155 | |
| 156 | static int clk_composite_is_enabled(struct clk_hw *hw) |
| 157 | { |
| 158 | struct clk_composite *composite = to_clk_composite(hw); |
| 159 | const struct clk_ops *gate_ops = composite->gate_ops; |
| 160 | struct clk_hw *gate_hw = composite->gate_hw; |
| 161 | |
| 162 | __clk_hw_set_clk(gate_hw, hw); |
| 163 | |
| 164 | return gate_ops->is_enabled(gate_hw); |
| 165 | } |
| 166 | |
| 167 | static int clk_composite_enable(struct clk_hw *hw) |
| 168 | { |
| 169 | struct clk_composite *composite = to_clk_composite(hw); |
| 170 | const struct clk_ops *gate_ops = composite->gate_ops; |
| 171 | struct clk_hw *gate_hw = composite->gate_hw; |
| 172 | |
| 173 | __clk_hw_set_clk(gate_hw, hw); |
| 174 | |
| 175 | return gate_ops->enable(gate_hw); |
| 176 | } |
| 177 | |
| 178 | static void clk_composite_disable(struct clk_hw *hw) |
| 179 | { |
| 180 | struct clk_composite *composite = to_clk_composite(hw); |
| 181 | const struct clk_ops *gate_ops = composite->gate_ops; |
| 182 | struct clk_hw *gate_hw = composite->gate_hw; |
| 183 | |
| 184 | __clk_hw_set_clk(gate_hw, hw); |
| 185 | |
| 186 | gate_ops->disable(gate_hw); |
| 187 | } |
| 188 | |
| 189 | struct clk *clk_register_composite(struct device *dev, const char *name, |
| 190 | const char * const *parent_names, int num_parents, |
| 191 | struct clk_hw *mux_hw, const struct clk_ops *mux_ops, |
| 192 | struct clk_hw *rate_hw, const struct clk_ops *rate_ops, |
| 193 | struct clk_hw *gate_hw, const struct clk_ops *gate_ops, |
| 194 | unsigned long flags) |
| 195 | { |
| 196 | struct clk *clk; |
| 197 | struct clk_init_data init; |
| 198 | struct clk_composite *composite; |
| 199 | struct clk_ops *clk_composite_ops; |
| 200 | |
| 201 | composite = kzalloc(sizeof(*composite), GFP_KERNEL); |
| 202 | if (!composite) |
| 203 | return ERR_PTR(-ENOMEM); |
| 204 | |
| 205 | init.name = name; |
| 206 | init.flags = flags | CLK_IS_BASIC; |
| 207 | init.parent_names = parent_names; |
| 208 | init.num_parents = num_parents; |
| 209 | |
| 210 | clk_composite_ops = &composite->ops; |
| 211 | |
| 212 | if (mux_hw && mux_ops) { |
| 213 | if (!mux_ops->get_parent) { |
| 214 | clk = ERR_PTR(-EINVAL); |
| 215 | goto err; |
| 216 | } |
| 217 | |
| 218 | composite->mux_hw = mux_hw; |
| 219 | composite->mux_ops = mux_ops; |
| 220 | clk_composite_ops->get_parent = clk_composite_get_parent; |
| 221 | if (mux_ops->set_parent) |
| 222 | clk_composite_ops->set_parent = clk_composite_set_parent; |
| 223 | if (mux_ops->determine_rate) |
| 224 | clk_composite_ops->determine_rate = clk_composite_determine_rate; |
| 225 | } |
| 226 | |
| 227 | if (rate_hw && rate_ops) { |
| 228 | if (!rate_ops->recalc_rate) { |
| 229 | clk = ERR_PTR(-EINVAL); |
| 230 | goto err; |
| 231 | } |
| 232 | clk_composite_ops->recalc_rate = clk_composite_recalc_rate; |
| 233 | |
| 234 | if (rate_ops->determine_rate) |
| 235 | clk_composite_ops->determine_rate = |
| 236 | clk_composite_determine_rate; |
| 237 | else if (rate_ops->round_rate) |
| 238 | clk_composite_ops->round_rate = |
| 239 | clk_composite_round_rate; |
| 240 | |
| 241 | /* .set_rate requires either .round_rate or .determine_rate */ |
| 242 | if (rate_ops->set_rate) { |
| 243 | if (rate_ops->determine_rate || rate_ops->round_rate) |
| 244 | clk_composite_ops->set_rate = |
| 245 | clk_composite_set_rate; |
| 246 | else |
| 247 | WARN(1, "%s: missing round_rate op is required\n", |
| 248 | __func__); |
| 249 | } |
| 250 | |
| 251 | composite->rate_hw = rate_hw; |
| 252 | composite->rate_ops = rate_ops; |
| 253 | } |
| 254 | |
| 255 | if (gate_hw && gate_ops) { |
| 256 | if (!gate_ops->is_enabled || !gate_ops->enable || |
| 257 | !gate_ops->disable) { |
| 258 | clk = ERR_PTR(-EINVAL); |
| 259 | goto err; |
| 260 | } |
| 261 | |
| 262 | composite->gate_hw = gate_hw; |
| 263 | composite->gate_ops = gate_ops; |
| 264 | clk_composite_ops->is_enabled = clk_composite_is_enabled; |
| 265 | clk_composite_ops->enable = clk_composite_enable; |
| 266 | clk_composite_ops->disable = clk_composite_disable; |
| 267 | } |
| 268 | |
| 269 | init.ops = clk_composite_ops; |
| 270 | composite->hw.init = &init; |
| 271 | |
| 272 | clk = clk_register(dev, &composite->hw); |
| 273 | if (IS_ERR(clk)) |
| 274 | goto err; |
| 275 | |
| 276 | if (composite->mux_hw) |
| 277 | composite->mux_hw->clk = clk; |
| 278 | |
| 279 | if (composite->rate_hw) |
| 280 | composite->rate_hw->clk = clk; |
| 281 | |
| 282 | if (composite->gate_hw) |
| 283 | composite->gate_hw->clk = clk; |
| 284 | |
| 285 | return clk; |
| 286 | |
| 287 | err: |
| 288 | kfree(composite); |
| 289 | return clk; |
| 290 | } |