1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de> 4 */ 5 #include <linux/module.h> 6 #include <linux/clk-provider.h> 7 #include <linux/slab.h> 8 #include <linux/err.h> 9 #include <linux/of.h> 10 #include <linux/platform_device.h> 11 12 /* 13 * DOC: basic fixed multiplier and divider clock that cannot gate 14 * 15 * Traits of this clock: 16 * prepare - clk_prepare only ensures that parents are prepared 17 * enable - clk_enable only ensures that parents are enabled 18 * rate - rate is fixed. clk->rate = parent->rate / div * mult 19 * parent - fixed parent. No clk_set_parent support 20 */ 21 22 static unsigned long clk_factor_recalc_rate(struct clk_hw *hw, 23 unsigned long parent_rate) 24 { 25 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); 26 unsigned long long int rate; 27 28 rate = (unsigned long long int)parent_rate * fix->mult; 29 do_div(rate, fix->div); 30 return (unsigned long)rate; 31 } 32 33 static int clk_factor_determine_rate(struct clk_hw *hw, 34 struct clk_rate_request *req) 35 { 36 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); 37 38 if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { 39 struct clk_hw *parent_hw = clk_hw_get_parent(hw); 40 unsigned long best_parent; 41 42 if (!parent_hw) 43 return -EINVAL; 44 45 best_parent = (req->rate / fix->mult) * fix->div; 46 req->best_parent_rate = clk_hw_round_rate(parent_hw, best_parent); 47 } 48 49 req->rate = (req->best_parent_rate / fix->div) * fix->mult; 50 51 return 0; 52 } 53 54 static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate, 55 unsigned long parent_rate) 56 { 57 /* 58 * We must report success but we can do so unconditionally because 59 * clk_factor_determine_rate returns values that ensure this call is a 60 * nop. 61 */ 62 63 return 0; 64 } 65 66 static unsigned long clk_factor_recalc_accuracy(struct clk_hw *hw, 67 unsigned long parent_accuracy) 68 { 69 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); 70 71 if (fix->flags & CLK_FIXED_FACTOR_FIXED_ACCURACY) 72 return fix->acc; 73 74 return parent_accuracy; 75 } 76 77 const struct clk_ops clk_fixed_factor_ops = { 78 .determine_rate = clk_factor_determine_rate, 79 .set_rate = clk_factor_set_rate, 80 .recalc_rate = clk_factor_recalc_rate, 81 .recalc_accuracy = clk_factor_recalc_accuracy, 82 }; 83 EXPORT_SYMBOL_GPL(clk_fixed_factor_ops); 84 85 static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res) 86 { 87 struct clk_fixed_factor *fix = res; 88 89 /* 90 * We can not use clk_hw_unregister_fixed_factor, since it will kfree() 91 * the hw, resulting in double free. Just unregister the hw and let 92 * devres code kfree() it. 93 */ 94 clk_hw_unregister(&fix->hw); 95 } 96 97 struct clk_hw * 98 __clk_hw_register_fixed_factor(struct device *dev, struct device_node *np, 99 const char *name, const char *parent_name, 100 const struct clk_hw *parent_hw, const struct clk_parent_data *pdata, 101 unsigned long flags, unsigned int mult, unsigned int div, 102 unsigned long acc, unsigned int fixflags, bool devm) 103 { 104 struct clk_fixed_factor *fix; 105 struct clk_init_data init = { }; 106 struct clk_hw *hw; 107 int ret; 108 109 /* You can't use devm without a dev */ 110 if (devm && !dev) 111 return ERR_PTR(-EINVAL); 112 113 if (devm) 114 fix = devres_alloc(devm_clk_hw_register_fixed_factor_release, 115 sizeof(*fix), GFP_KERNEL); 116 else 117 fix = kmalloc_obj(*fix); 118 if (!fix) 119 return ERR_PTR(-ENOMEM); 120 121 /* struct clk_fixed_factor assignments */ 122 fix->mult = mult; 123 fix->div = div; 124 fix->hw.init = &init; 125 fix->acc = acc; 126 fix->flags = fixflags; 127 128 init.name = name; 129 init.ops = &clk_fixed_factor_ops; 130 init.flags = flags; 131 init.parent_names = parent_name ? &parent_name : NULL; 132 init.parent_hws = parent_hw ? &parent_hw : NULL; 133 init.parent_data = pdata; 134 if (parent_name || parent_hw || pdata) 135 init.num_parents = 1; 136 else 137 init.num_parents = 0; 138 139 hw = &fix->hw; 140 if (dev) 141 ret = clk_hw_register(dev, hw); 142 else 143 ret = of_clk_hw_register(np, hw); 144 if (ret) { 145 if (devm) 146 devres_free(fix); 147 else 148 kfree(fix); 149 hw = ERR_PTR(ret); 150 } else if (devm) 151 devres_add(dev, fix); 152 153 return hw; 154 } 155 EXPORT_SYMBOL_GPL(__clk_hw_register_fixed_factor); 156 157 /** 158 * devm_clk_hw_register_fixed_factor_index - Register a fixed factor clock with 159 * parent from DT index 160 * @dev: device that is registering this clock 161 * @name: name of this clock 162 * @index: index of phandle in @dev 'clocks' property 163 * @flags: fixed factor flags 164 * @mult: multiplier 165 * @div: divider 166 * 167 * Return: Pointer to fixed factor clk_hw structure that was registered or 168 * an error pointer. 169 */ 170 struct clk_hw *devm_clk_hw_register_fixed_factor_index(struct device *dev, 171 const char *name, unsigned int index, unsigned long flags, 172 unsigned int mult, unsigned int div) 173 { 174 const struct clk_parent_data pdata = { .index = index }; 175 176 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, &pdata, 177 flags, mult, div, 0, 0, true); 178 } 179 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_index); 180 181 struct clk_hw *clk_hw_register_fixed_factor_fwname(struct device *dev, 182 struct device_node *np, const char *name, const char *fw_name, 183 unsigned long flags, unsigned int mult, unsigned int div) 184 { 185 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name }; 186 187 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL, 188 &pdata, flags, mult, div, 0, 0, false); 189 } 190 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_fwname); 191 192 struct clk_hw *clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev, 193 struct device_node *np, const char *name, const char *fw_name, 194 unsigned long flags, unsigned int mult, unsigned int div, 195 unsigned long acc) 196 { 197 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name }; 198 199 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL, 200 &pdata, flags, mult, div, acc, 201 CLK_FIXED_FACTOR_FIXED_ACCURACY, false); 202 } 203 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_with_accuracy_fwname); 204 205 struct clk_hw *clk_hw_register_fixed_factor_index(struct device *dev, 206 const char *name, unsigned int index, unsigned long flags, 207 unsigned int mult, unsigned int div) 208 { 209 const struct clk_parent_data pdata = { .index = index }; 210 211 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, &pdata, 212 flags, mult, div, 0, 0, false); 213 } 214 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_index); 215 216 struct clk *clk_register_fixed_factor(struct device *dev, const char *name, 217 const char *parent_name, unsigned long flags, 218 unsigned int mult, unsigned int div) 219 { 220 struct clk_hw *hw; 221 222 hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult, 223 div); 224 if (IS_ERR(hw)) 225 return ERR_CAST(hw); 226 return hw->clk; 227 } 228 EXPORT_SYMBOL_GPL(clk_register_fixed_factor); 229 230 void clk_unregister_fixed_factor(struct clk *clk) 231 { 232 struct clk_hw *hw; 233 234 hw = __clk_get_hw(clk); 235 if (!hw) 236 return; 237 238 clk_unregister(clk); 239 kfree(to_clk_fixed_factor(hw)); 240 } 241 EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor); 242 243 void clk_hw_unregister_fixed_factor(struct clk_hw *hw) 244 { 245 struct clk_fixed_factor *fix; 246 247 fix = to_clk_fixed_factor(hw); 248 249 clk_hw_unregister(hw); 250 kfree(fix); 251 } 252 EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor); 253 254 struct clk_hw *devm_clk_hw_register_fixed_factor_fwname(struct device *dev, 255 struct device_node *np, const char *name, const char *fw_name, 256 unsigned long flags, unsigned int mult, unsigned int div) 257 { 258 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name }; 259 260 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL, 261 &pdata, flags, mult, div, 0, 0, true); 262 } 263 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_fwname); 264 265 struct clk_hw *devm_clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev, 266 struct device_node *np, const char *name, const char *fw_name, 267 unsigned long flags, unsigned int mult, unsigned int div, 268 unsigned long acc) 269 { 270 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name }; 271 272 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL, 273 &pdata, flags, mult, div, acc, 274 CLK_FIXED_FACTOR_FIXED_ACCURACY, true); 275 } 276 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_with_accuracy_fwname); 277 278 #ifdef CONFIG_OF 279 static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node) 280 { 281 struct clk_hw *hw; 282 const char *clk_name = node->name; 283 const struct clk_parent_data pdata = { .index = 0 }; 284 u32 div, mult; 285 int ret; 286 287 if (of_property_read_u32(node, "clock-div", &div)) { 288 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n", 289 __func__, node); 290 return ERR_PTR(-EIO); 291 } 292 293 if (of_property_read_u32(node, "clock-mult", &mult)) { 294 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n", 295 __func__, node); 296 return ERR_PTR(-EIO); 297 } 298 299 of_property_read_string(node, "clock-output-names", &clk_name); 300 301 hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, NULL, 302 &pdata, 0, mult, div, 0, 0, false); 303 if (IS_ERR(hw)) { 304 /* 305 * Clear OF_POPULATED flag so that clock registration can be 306 * attempted again from probe function. 307 */ 308 of_node_clear_flag(node, OF_POPULATED); 309 return ERR_CAST(hw); 310 } 311 312 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw); 313 if (ret) { 314 clk_hw_unregister_fixed_factor(hw); 315 return ERR_PTR(ret); 316 } 317 318 return hw; 319 } 320 321 /** 322 * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock 323 * @node: device node for the clock 324 */ 325 void __init of_fixed_factor_clk_setup(struct device_node *node) 326 { 327 _of_fixed_factor_clk_setup(node); 328 } 329 CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock", 330 of_fixed_factor_clk_setup); 331 332 static void of_fixed_factor_clk_remove(struct platform_device *pdev) 333 { 334 struct clk_hw *clk = platform_get_drvdata(pdev); 335 336 of_clk_del_provider(pdev->dev.of_node); 337 clk_hw_unregister_fixed_factor(clk); 338 } 339 340 static int of_fixed_factor_clk_probe(struct platform_device *pdev) 341 { 342 struct clk_hw *clk; 343 344 /* 345 * This function is not executed when of_fixed_factor_clk_setup 346 * succeeded. 347 */ 348 clk = _of_fixed_factor_clk_setup(pdev->dev.of_node); 349 if (IS_ERR(clk)) 350 return PTR_ERR(clk); 351 352 platform_set_drvdata(pdev, clk); 353 354 return 0; 355 } 356 357 static const struct of_device_id of_fixed_factor_clk_ids[] = { 358 { .compatible = "fixed-factor-clock" }, 359 { } 360 }; 361 MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids); 362 363 static struct platform_driver of_fixed_factor_clk_driver = { 364 .driver = { 365 .name = "of_fixed_factor_clk", 366 .of_match_table = of_fixed_factor_clk_ids, 367 }, 368 .probe = of_fixed_factor_clk_probe, 369 .remove = of_fixed_factor_clk_remove, 370 }; 371 builtin_platform_driver(of_fixed_factor_clk_driver); 372 #endif 373