412 lines · c
1// SPDX-License-Identifier: GPL-2.02/*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 gate14 *15 * Traits of this clock:16 * prepare - clk_prepare only ensures that parents are prepared17 * enable - clk_enable only ensures that parents are enabled18 * rate - rate is fixed. clk->rate = parent->rate / div * mult19 * parent - fixed parent. No clk_set_parent support20 */21 22static 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 33static 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 48static 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 because53 * clk_factor_round_rate returns values that ensure this call is a54 * nop.55 */56 57 return 0;58}59 60static 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 71const 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};77EXPORT_SYMBOL_GPL(clk_fixed_factor_ops);78 79static 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 let86 * devres code kfree() it.87 */88 clk_hw_unregister(&fix->hw);89}90 91static struct clk_hw *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 else111 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 else130 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 else137 ret = of_clk_hw_register(np, hw);138 if (ret) {139 if (devm)140 devres_free(fix);141 else142 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 with152 * parent from DT index153 * @dev: device that is registering this clock154 * @name: name of this clock155 * @index: index of phandle in @dev 'clocks' property156 * @flags: fixed factor flags157 * @mult: multiplier158 * @div: divider159 *160 * Return: Pointer to fixed factor clk_hw structure that was registered or161 * an error pointer.162 */163struct 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}172EXPORT_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 with176 * pointer to parent clock177 * @dev: device that is registering this clock178 * @name: name of this clock179 * @parent_hw: pointer to parent clk180 * @flags: fixed factor flags181 * @mult: multiplier182 * @div: divider183 *184 * Return: Pointer to fixed factor clk_hw structure that was registered or185 * an error pointer.186 */187struct 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}196EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_parent_hw);197 198struct 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}207EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_parent_hw);208 209struct 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}218EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor);219 220struct 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}229EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_fwname);230 231struct 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}242EXPORT_SYMBOL_GPL(clk_hw_register_fixed_factor_with_accuracy_fwname);243 244struct 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}256EXPORT_SYMBOL_GPL(clk_register_fixed_factor);257 258void 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}269EXPORT_SYMBOL_GPL(clk_unregister_fixed_factor);270 271void 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}280EXPORT_SYMBOL_GPL(clk_hw_unregister_fixed_factor);281 282struct 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}291EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor);292 293struct 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}302EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_fwname);303 304struct 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}315EXPORT_SYMBOL_GPL(devm_clk_hw_register_fixed_factor_with_accuracy_fwname);316 317#ifdef CONFIG_OF318static 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 be345 * 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 clock362 * @node: device node for the clock363 */364void __init of_fixed_factor_clk_setup(struct device_node *node)365{366 _of_fixed_factor_clk_setup(node);367}368CLK_OF_DECLARE(fixed_factor_clk, "fixed-factor-clock",369 of_fixed_factor_clk_setup);370 371static 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 379static 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_setup385 * 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 396static const struct of_device_id of_fixed_factor_clk_ids[] = {397 { .compatible = "fixed-factor-clock" },398 { }399};400MODULE_DEVICE_TABLE(of, of_fixed_factor_clk_ids);401 402static 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};410builtin_platform_driver(of_fixed_factor_clk_driver);411#endif412