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 clk_factor_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)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 clk_factor_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)33 static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate, 34 unsigned long *prate) 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 unsigned long best_parent; 40 41 best_parent = (rate / fix->mult) * fix->div; 42 *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent); 43 } 44 45 return (*prate / fix->div) * fix->mult; 46 } 47 clk_factor_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)48 static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate, 49 unsigned long parent_rate) 50 { 51 /* 52 * We must report success but we can do so unconditionally because 53 * clk_factor_round_rate returns values that ensure this call is a 54 * nop. 55 */ 56 57 return 0; 58 } 59 clk_factor_recalc_accuracy(struct clk_hw * hw,unsigned long parent_accuracy)60 static unsigned long clk_factor_recalc_accuracy(struct clk_hw *hw, 61 unsigned long parent_accuracy) 62 { 63 struct clk_fixed_factor *fix = to_clk_fixed_factor(hw); 64 65 if (fix->flags & CLK_FIXED_FACTOR_FIXED_ACCURACY) 66 return fix->acc; 67 68 return parent_accuracy; 69 } 70 71 const struct clk_ops clk_fixed_factor_ops = { 72 .round_rate = clk_factor_round_rate, 73 .set_rate = clk_factor_set_rate, 74 .recalc_rate = clk_factor_recalc_rate, 75 .recalc_accuracy = clk_factor_recalc_accuracy, 76 }; 77 EXPORT_SYMBOL_GPL(clk_fixed_factor_ops); 78 devm_clk_hw_register_fixed_factor_release(struct device * dev,void * res)79 static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res) 80 { 81 struct clk_fixed_factor *fix = res; 82 83 /* 84 * We can not use clk_hw_unregister_fixed_factor, since it will kfree() 85 * the hw, resulting in double free. Just unregister the hw and let 86 * devres code kfree() it. 87 */ 88 clk_hw_unregister(&fix->hw); 89 } 90 91 static struct clk_hw * __clk_hw_register_fixed_factor(struct device * dev,struct device_node * np,const char * name,const char * parent_name,const struct clk_hw * parent_hw,const struct clk_parent_data * pdata,unsigned long flags,unsigned int mult,unsigned int div,unsigned long acc,unsigned int fixflags,bool devm)92 __clk_hw_register_fixed_factor(struct device *dev, struct device_node *np, 93 const char *name, const char *parent_name, 94 const struct clk_hw *parent_hw, const struct clk_parent_data *pdata, 95 unsigned long flags, unsigned int mult, unsigned int div, 96 unsigned long acc, unsigned int fixflags, bool devm) 97 { 98 struct clk_fixed_factor *fix; 99 struct clk_init_data init = { }; 100 struct clk_hw *hw; 101 int ret; 102 103 /* You can't use devm without a dev */ 104 if (devm && !dev) 105 return ERR_PTR(-EINVAL); 106 107 if (devm) 108 fix = devres_alloc(devm_clk_hw_register_fixed_factor_release, 109 sizeof(*fix), GFP_KERNEL); 110 else 111 fix = kmalloc(sizeof(*fix), GFP_KERNEL); 112 if (!fix) 113 return ERR_PTR(-ENOMEM); 114 115 /* struct clk_fixed_factor assignments */ 116 fix->mult = mult; 117 fix->div = div; 118 fix->hw.init = &init; 119 fix->acc = acc; 120 fix->flags = fixflags; 121 122 init.name = name; 123 init.ops = &clk_fixed_factor_ops; 124 init.flags = flags; 125 if (parent_name) 126 init.parent_names = &parent_name; 127 else if (parent_hw) 128 init.parent_hws = &parent_hw; 129 else 130 init.parent_data = pdata; 131 init.num_parents = 1; 132 133 hw = &fix->hw; 134 if (dev) 135 ret = clk_hw_register(dev, hw); 136 else 137 ret = of_clk_hw_register(np, hw); 138 if (ret) { 139 if (devm) 140 devres_free(fix); 141 else 142 kfree(fix); 143 hw = ERR_PTR(ret); 144 } else if (devm) 145 devres_add(dev, fix); 146 147 return hw; 148 } 149 150 /** 151 * devm_clk_hw_register_fixed_factor_index - Register a fixed factor clock with 152 * parent from DT index 153 * @dev: device that is registering this clock 154 * @name: name of this clock 155 * @index: index of phandle in @dev 'clocks' property 156 * @flags: fixed factor flags 157 * @mult: multiplier 158 * @div: divider 159 * 160 * Return: Pointer to fixed factor clk_hw structure that was registered or 161 * an error pointer. 162 */ devm_clk_hw_register_fixed_factor_index(struct device * dev,const char * name,unsigned int index,unsigned long flags,unsigned int mult,unsigned int div)163 struct clk_hw *devm_clk_hw_register_fixed_factor_index(struct device *dev, 164 const char *name, unsigned int index, unsigned long flags, 165 unsigned int mult, unsigned int div) 166 { 167 const struct clk_parent_data pdata = { .index = index }; 168 169 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, NULL, &pdata, 170 flags, mult, div, 0, 0, true); 171 } 172 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_index); 173 174 /** 175 * devm_clk_hw_register_fixed_factor_parent_hw - Register a fixed factor clock with 176 * pointer to parent clock 177 * @dev: device that is registering this clock 178 * @name: name of this clock 179 * @parent_hw: pointer to parent clk 180 * @flags: fixed factor flags 181 * @mult: multiplier 182 * @div: divider 183 * 184 * Return: Pointer to fixed factor clk_hw structure that was registered or 185 * an error pointer. 186 */ devm_clk_hw_register_fixed_factor_parent_hw(struct device * dev,const char * name,const struct clk_hw * parent_hw,unsigned long flags,unsigned int mult,unsigned int div)187 struct clk_hw *devm_clk_hw_register_fixed_factor_parent_hw(struct device *dev, 188 const char *name, const struct clk_hw *parent_hw, 189 unsigned long flags, unsigned int mult, unsigned int div) 190 { 191 const struct clk_parent_data pdata = { .index = -1 }; 192 193 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw, 194 &pdata, flags, mult, div, 0, 0, true); 195 } 196 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_parent_hw); 197 clk_hw_register_fixed_factor_parent_hw(struct device * dev,const char * name,const struct clk_hw * parent_hw,unsigned long flags,unsigned int mult,unsigned int div)198 struct clk_hw *clk_hw_register_fixed_factor_parent_hw(struct device *dev, 199 const char *name, const struct clk_hw *parent_hw, 200 unsigned long flags, unsigned int mult, unsigned int div) 201 { 202 const struct clk_parent_data pdata = { .index = -1 }; 203 204 return __clk_hw_register_fixed_factor(dev, NULL, name, NULL, parent_hw, 205 &pdata, flags, mult, div, 0, 0, false); 206 } 207 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_parent_hw); 208 clk_hw_register_fixed_factor(struct device * dev,const char * name,const char * parent_name,unsigned long flags,unsigned int mult,unsigned int div)209 struct clk_hw *clk_hw_register_fixed_factor(struct device *dev, 210 const char *name, const char *parent_name, unsigned long flags, 211 unsigned int mult, unsigned int div) 212 { 213 const struct clk_parent_data pdata = { .index = -1 }; 214 215 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL, 216 &pdata, flags, mult, div, 0, 0, false); 217 } 218 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor); 219 clk_hw_register_fixed_factor_fwname(struct device * dev,struct device_node * np,const char * name,const char * fw_name,unsigned long flags,unsigned int mult,unsigned int div)220 struct clk_hw *clk_hw_register_fixed_factor_fwname(struct device *dev, 221 struct device_node *np, const char *name, const char *fw_name, 222 unsigned long flags, unsigned int mult, unsigned int div) 223 { 224 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name }; 225 226 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL, 227 &pdata, flags, mult, div, 0, 0, false); 228 } 229 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_fwname); 230 clk_hw_register_fixed_factor_with_accuracy_fwname(struct device * dev,struct device_node * np,const char * name,const char * fw_name,unsigned long flags,unsigned int mult,unsigned int div,unsigned long acc)231 struct clk_hw *clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev, 232 struct device_node *np, const char *name, const char *fw_name, 233 unsigned long flags, unsigned int mult, unsigned int div, 234 unsigned long acc) 235 { 236 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name }; 237 238 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL, 239 &pdata, flags, mult, div, acc, 240 CLK_FIXED_FACTOR_FIXED_ACCURACY, false); 241 } 242 EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_with_accuracy_fwname); 243 clk_register_fixed_factor(struct device * dev,const char * name,const char * parent_name,unsigned long flags,unsigned int mult,unsigned int div)244 struct clk *clk_register_fixed_factor(struct device *dev, const char *name, 245 const char *parent_name, unsigned long flags, 246 unsigned int mult, unsigned int div) 247 { 248 struct clk_hw *hw; 249 250 hw = clk_hw_register_fixed_factor(dev, name, parent_name, flags, mult, 251 div); 252 if (IS_ERR(hw)) 253 return ERR_CAST(hw); 254 return hw->clk; 255 } 256 EXPORT_SYMBOL_GPL(clk_register_fixed_factor); 257 clk_unregister_fixed_factor(struct clk * clk)258 void clk_unregister_fixed_factor(struct clk *clk) 259 { 260 struct clk_hw *hw; 261 262 hw = __clk_get_hw(clk); 263 if (!hw) 264 return; 265 266 clk_unregister(clk); 267 kfree(to_clk_fixed_factor(hw)); 268 } 269 EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor); 270 clk_hw_unregister_fixed_factor(struct clk_hw * hw)271 void clk_hw_unregister_fixed_factor(struct clk_hw *hw) 272 { 273 struct clk_fixed_factor *fix; 274 275 fix = to_clk_fixed_factor(hw); 276 277 clk_hw_unregister(hw); 278 kfree(fix); 279 } 280 EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor); 281 devm_clk_hw_register_fixed_factor(struct device * dev,const char * name,const char * parent_name,unsigned long flags,unsigned int mult,unsigned int div)282 struct clk_hw *devm_clk_hw_register_fixed_factor(struct device *dev, 283 const char *name, const char *parent_name, unsigned long flags, 284 unsigned int mult, unsigned int div) 285 { 286 const struct clk_parent_data pdata = { .index = -1 }; 287 288 return __clk_hw_register_fixed_factor(dev, NULL, name, parent_name, NULL, 289 &pdata, flags, mult, div, 0, 0, true); 290 } 291 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor); 292 devm_clk_hw_register_fixed_factor_fwname(struct device * dev,struct device_node * np,const char * name,const char * fw_name,unsigned long flags,unsigned int mult,unsigned int div)293 struct clk_hw *devm_clk_hw_register_fixed_factor_fwname(struct device *dev, 294 struct device_node *np, const char *name, const char *fw_name, 295 unsigned long flags, unsigned int mult, unsigned int div) 296 { 297 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name }; 298 299 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL, 300 &pdata, flags, mult, div, 0, 0, true); 301 } 302 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_fwname); 303 devm_clk_hw_register_fixed_factor_with_accuracy_fwname(struct device * dev,struct device_node * np,const char * name,const char * fw_name,unsigned long flags,unsigned int mult,unsigned int div,unsigned long acc)304 struct clk_hw *devm_clk_hw_register_fixed_factor_with_accuracy_fwname(struct device *dev, 305 struct device_node *np, const char *name, const char *fw_name, 306 unsigned long flags, unsigned int mult, unsigned int div, 307 unsigned long acc) 308 { 309 const struct clk_parent_data pdata = { .index = -1, .fw_name = fw_name }; 310 311 return __clk_hw_register_fixed_factor(dev, np, name, NULL, NULL, 312 &pdata, flags, mult, div, acc, 313 CLK_FIXED_FACTOR_FIXED_ACCURACY, true); 314 } 315 EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_with_accuracy_fwname); 316 317 #ifdef CONFIG_OF _of_fixed_factor_clk_setup(struct device_node * node)318 static struct clk_hw *_of_fixed_factor_clk_setup(struct device_node *node) 319 { 320 struct clk_hw *hw; 321 const char *clk_name = node->name; 322 const struct clk_parent_data pdata = { .index = 0 }; 323 u32 div, mult; 324 int ret; 325 326 if (of_property_read_u32(node, "clock-div", &div)) { 327 pr_err("%s Fixed factor clock <%pOFn> must have a clock-div property\n", 328 __func__, node); 329 return ERR_PTR(-EIO); 330 } 331 332 if (of_property_read_u32(node, "clock-mult", &mult)) { 333 pr_err("%s Fixed factor clock <%pOFn> must have a clock-mult property\n", 334 __func__, node); 335 return ERR_PTR(-EIO); 336 } 337 338 of_property_read_string(node, "clock-output-names", &clk_name); 339 340 hw = __clk_hw_register_fixed_factor(NULL, node, clk_name, NULL, NULL, 341 &pdata, 0, mult, div, 0, 0, false); 342 if (IS_ERR(hw)) { 343 /* 344 * Clear OF_POPULATED flag so that clock registration can be 345 * attempted again from probe function. 346 */ 347 of_node_clear_flag(node, OF_POPULATED); 348 return ERR_CAST(hw); 349 } 350 351 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw); 352 if (ret) { 353 clk_hw_unregister_fixed_factor(hw); 354 return ERR_PTR(ret); 355 } 356 357 return hw; 358 } 359 360 /** 361 * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock 362 * @node: device node for the clock 363 */ of_fixed_factor_clk_setup(struct device_node * node)364 void __init of_fixed_factor_clk_setup(struct device_node *node) 365 { 366 _of_fixed_factor_clk_setup(node); 367 } 368 CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock", 369 of_fixed_factor_clk_setup); 370 of_fixed_factor_clk_remove(struct platform_device * pdev)371 static void of_fixed_factor_clk_remove(struct platform_device *pdev) 372 { 373 struct clk_hw *clk = platform_get_drvdata(pdev); 374 375 of_clk_del_provider(pdev->dev.of_node); 376 clk_hw_unregister_fixed_factor(clk); 377 } 378 of_fixed_factor_clk_probe(struct platform_device * pdev)379 static int of_fixed_factor_clk_probe(struct platform_device *pdev) 380 { 381 struct clk_hw *clk; 382 383 /* 384 * This function is not executed when of_fixed_factor_clk_setup 385 * succeeded. 386 */ 387 clk = _of_fixed_factor_clk_setup(pdev->dev.of_node); 388 if (IS_ERR(clk)) 389 return PTR_ERR(clk); 390 391 platform_set_drvdata(pdev, clk); 392 393 return 0; 394 } 395 396 static const struct of_device_id of_fixed_factor_clk_ids[] = { 397 { .compatible = "fixed-factor-clock" }, 398 { } 399 }; 400 MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids); 401 402 static struct platform_driver of_fixed_factor_clk_driver = { 403 .driver = { 404 .name = "of_fixed_factor_clk", 405 .of_match_table = of_fixed_factor_clk_ids, 406 }, 407 .probe = of_fixed_factor_clk_probe, 408 .remove = of_fixed_factor_clk_remove, 409 }; 410 builtin_platform_driver(of_fixed_factor_clk_driver); 411 #endif 412