4 * Copyright (C) 2013 Texas Instruments, Inc.
6 * Tero Kristo <t-kristo@ti.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
13 * kind, whether express or implied; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 #include <linux/clk-provider.h>
19 #include <linux/slab.h>
20 #include <linux/err.h>
22 #include <linux/of_address.h>
23 #include <linux/clk/ti.h>
27 #define pr_fmt(fmt) "%s: " fmt, __func__
29 #define div_mask(d) ((1 << ((d)->width)) - 1)
31 static unsigned int _get_table_maxdiv(const struct clk_div_table *table)
33 unsigned int maxdiv = 0;
34 const struct clk_div_table *clkt;
36 for (clkt = table; clkt->div; clkt++)
37 if (clkt->div > maxdiv)
42 static unsigned int _get_maxdiv(struct clk_divider *divider)
44 if (divider->flags & CLK_DIVIDER_ONE_BASED)
45 return div_mask(divider);
46 if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
47 return 1 << div_mask(divider);
49 return _get_table_maxdiv(divider->table);
50 return div_mask(divider) + 1;
53 static unsigned int _get_table_div(const struct clk_div_table *table,
56 const struct clk_div_table *clkt;
58 for (clkt = table; clkt->div; clkt++)
64 static unsigned int _get_div(struct clk_divider *divider, unsigned int val)
66 if (divider->flags & CLK_DIVIDER_ONE_BASED)
68 if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
71 return _get_table_div(divider->table, val);
75 static unsigned int _get_table_val(const struct clk_div_table *table,
78 const struct clk_div_table *clkt;
80 for (clkt = table; clkt->div; clkt++)
86 static unsigned int _get_val(struct clk_divider *divider, u8 div)
88 if (divider->flags & CLK_DIVIDER_ONE_BASED)
90 if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
93 return _get_table_val(divider->table, div);
97 static unsigned long ti_clk_divider_recalc_rate(struct clk_hw *hw,
98 unsigned long parent_rate)
100 struct clk_divider *divider = to_clk_divider(hw);
101 unsigned int div, val;
103 val = ti_clk_ll_ops->clk_readl(divider->reg) >> divider->shift;
104 val &= div_mask(divider);
106 div = _get_div(divider, val);
108 WARN(!(divider->flags & CLK_DIVIDER_ALLOW_ZERO),
109 "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
110 clk_hw_get_name(hw));
114 return DIV_ROUND_UP(parent_rate, div);
118 * The reverse of DIV_ROUND_UP: The maximum number which
121 #define MULT_ROUND_UP(r, m) ((r) * (m) + (m) - 1)
123 static bool _is_valid_table_div(const struct clk_div_table *table,
126 const struct clk_div_table *clkt;
128 for (clkt = table; clkt->div; clkt++)
129 if (clkt->div == div)
134 static bool _is_valid_div(struct clk_divider *divider, unsigned int div)
136 if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
137 return is_power_of_2(div);
139 return _is_valid_table_div(divider->table, div);
143 static int _div_round_up(const struct clk_div_table *table,
144 unsigned long parent_rate, unsigned long rate)
146 const struct clk_div_table *clkt;
148 int div = DIV_ROUND_UP_ULL((u64)parent_rate, rate);
150 for (clkt = table; clkt->div; clkt++) {
151 if (clkt->div == div)
153 else if (clkt->div < div)
156 if ((clkt->div - div) < (up - div))
163 static int _div_round(const struct clk_div_table *table,
164 unsigned long parent_rate, unsigned long rate)
167 return DIV_ROUND_UP(parent_rate, rate);
169 return _div_round_up(table, parent_rate, rate);
172 static int ti_clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate,
173 unsigned long *best_parent_rate)
175 struct clk_divider *divider = to_clk_divider(hw);
177 unsigned long parent_rate, best = 0, now, maxdiv;
178 unsigned long parent_rate_saved = *best_parent_rate;
183 maxdiv = _get_maxdiv(divider);
185 if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
186 parent_rate = *best_parent_rate;
187 bestdiv = _div_round(divider->table, parent_rate, rate);
188 bestdiv = bestdiv == 0 ? 1 : bestdiv;
189 bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv;
194 * The maximum divider we can use without overflowing
195 * unsigned long in rate * i below
197 maxdiv = min(ULONG_MAX / rate, maxdiv);
199 for (i = 1; i <= maxdiv; i++) {
200 if (!_is_valid_div(divider, i))
202 if (rate * i == parent_rate_saved) {
204 * It's the most ideal case if the requested rate can be
205 * divided from parent clock without needing to change
206 * parent rate, so return the divider immediately.
208 *best_parent_rate = parent_rate_saved;
211 parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw),
212 MULT_ROUND_UP(rate, i));
213 now = DIV_ROUND_UP(parent_rate, i);
214 if (now <= rate && now > best) {
217 *best_parent_rate = parent_rate;
222 bestdiv = _get_maxdiv(divider);
224 clk_hw_round_rate(clk_hw_get_parent(hw), 1);
230 static long ti_clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
231 unsigned long *prate)
234 div = ti_clk_divider_bestdiv(hw, rate, prate);
236 return DIV_ROUND_UP(*prate, div);
239 static int ti_clk_divider_set_rate(struct clk_hw *hw, unsigned long rate,
240 unsigned long parent_rate)
242 struct clk_divider *divider;
243 unsigned int div, value;
249 divider = to_clk_divider(hw);
251 div = DIV_ROUND_UP(parent_rate, rate);
252 value = _get_val(divider, div);
254 if (value > div_mask(divider))
255 value = div_mask(divider);
257 if (divider->flags & CLK_DIVIDER_HIWORD_MASK) {
258 val = div_mask(divider) << (divider->shift + 16);
260 val = ti_clk_ll_ops->clk_readl(divider->reg);
261 val &= ~(div_mask(divider) << divider->shift);
263 val |= value << divider->shift;
264 ti_clk_ll_ops->clk_writel(val, divider->reg);
269 const struct clk_ops ti_clk_divider_ops = {
270 .recalc_rate = ti_clk_divider_recalc_rate,
271 .round_rate = ti_clk_divider_round_rate,
272 .set_rate = ti_clk_divider_set_rate,
275 static struct clk *_register_divider(struct device *dev, const char *name,
276 const char *parent_name,
277 unsigned long flags, void __iomem *reg,
278 u8 shift, u8 width, u8 clk_divider_flags,
279 const struct clk_div_table *table)
281 struct clk_divider *div;
283 struct clk_init_data init;
285 if (clk_divider_flags & CLK_DIVIDER_HIWORD_MASK) {
286 if (width + shift > 16) {
287 pr_warn("divider value exceeds LOWORD field\n");
288 return ERR_PTR(-EINVAL);
292 /* allocate the divider */
293 div = kzalloc(sizeof(*div), GFP_KERNEL);
295 pr_err("%s: could not allocate divider clk\n", __func__);
296 return ERR_PTR(-ENOMEM);
300 init.ops = &ti_clk_divider_ops;
301 init.flags = flags | CLK_IS_BASIC;
302 init.parent_names = (parent_name ? &parent_name : NULL);
303 init.num_parents = (parent_name ? 1 : 0);
305 /* struct clk_divider assignments */
309 div->flags = clk_divider_flags;
310 div->hw.init = &init;
313 /* register the clock */
314 clk = clk_register(dev, &div->hw);
322 static struct clk_div_table *
323 _get_div_table_from_setup(struct ti_clk_divider *setup, u8 *width)
326 struct clk_div_table *table;
332 if (!setup->num_dividers) {
333 /* Clk divider table not provided, determine min/max divs */
334 flags = setup->flags;
336 if (flags & CLKF_INDEX_STARTS_AT_ONE)
343 while (div < setup->max_div) {
344 if (flags & CLKF_INDEX_POWER_OF_TWO)
356 for (i = 0; i < setup->num_dividers; i++)
357 if (setup->dividers[i])
360 table = kzalloc(sizeof(*table) * (valid_div + 1), GFP_KERNEL);
362 return ERR_PTR(-ENOMEM);
367 for (i = 0; i < setup->num_dividers; i++)
368 if (setup->dividers[i]) {
369 table[valid_div].div = setup->dividers[i];
370 table[valid_div].val = i;
375 *width = fls(*width);
380 struct clk_hw *ti_clk_build_component_div(struct ti_clk_divider *setup)
382 struct clk_divider *div;
383 struct clk_omap_reg *reg;
388 div = kzalloc(sizeof(*div), GFP_KERNEL);
390 return ERR_PTR(-ENOMEM);
392 reg = (struct clk_omap_reg *)&div->reg;
393 reg->index = setup->module;
394 reg->offset = setup->reg;
396 if (setup->flags & CLKF_INDEX_STARTS_AT_ONE)
397 div->flags |= CLK_DIVIDER_ONE_BASED;
399 if (setup->flags & CLKF_INDEX_POWER_OF_TWO)
400 div->flags |= CLK_DIVIDER_POWER_OF_TWO;
402 div->table = _get_div_table_from_setup(setup, &div->width);
404 div->shift = setup->bit_shift;
409 struct clk *ti_clk_register_divider(struct ti_clk *setup)
411 struct ti_clk_divider *div;
412 struct clk_omap_reg *reg_setup;
417 struct clk_div_table *table;
422 reg_setup = (struct clk_omap_reg *)®
424 reg_setup->index = div->module;
425 reg_setup->offset = div->reg;
427 if (div->flags & CLKF_INDEX_STARTS_AT_ONE)
428 div_flags |= CLK_DIVIDER_ONE_BASED;
430 if (div->flags & CLKF_INDEX_POWER_OF_TWO)
431 div_flags |= CLK_DIVIDER_POWER_OF_TWO;
433 if (div->flags & CLKF_SET_RATE_PARENT)
434 flags |= CLK_SET_RATE_PARENT;
436 table = _get_div_table_from_setup(div, &width);
438 return (struct clk *)table;
440 clk = _register_divider(NULL, setup->name, div->parent,
441 flags, (void __iomem *)reg, div->bit_shift,
442 width, div_flags, table);
450 static struct clk_div_table *
451 __init ti_clk_get_div_table(struct device_node *node)
453 struct clk_div_table *table;
454 const __be32 *divspec;
460 divspec = of_get_property(node, "ti,dividers", &num_div);
469 /* Determine required size for divider table */
470 for (i = 0; i < num_div; i++) {
471 of_property_read_u32_index(node, "ti,dividers", i, &val);
477 pr_err("no valid dividers for %s table\n", node->name);
478 return ERR_PTR(-EINVAL);
481 table = kzalloc(sizeof(*table) * (valid_div + 1), GFP_KERNEL);
484 return ERR_PTR(-ENOMEM);
488 for (i = 0; i < num_div; i++) {
489 of_property_read_u32_index(node, "ti,dividers", i, &val);
491 table[valid_div].div = val;
492 table[valid_div].val = i;
500 static int _get_divider_width(struct device_node *node,
501 const struct clk_div_table *table,
510 /* Clk divider table not provided, determine min/max divs */
511 if (of_property_read_u32(node, "ti,min-div", &min_div))
514 if (of_property_read_u32(node, "ti,max-div", &max_div)) {
515 pr_err("no max-div for %s!\n", node->name);
519 /* Determine bit width for the field */
520 if (flags & CLK_DIVIDER_ONE_BASED)
525 while (div < max_div) {
526 if (flags & CLK_DIVIDER_POWER_OF_TWO)
535 while (table[div].div) {
536 val = table[div].val;
544 static int __init ti_clk_divider_populate(struct device_node *node,
545 void __iomem **reg, const struct clk_div_table **table,
546 u32 *flags, u8 *div_flags, u8 *width, u8 *shift)
550 *reg = ti_clk_get_reg_addr(node, 0);
552 return PTR_ERR(*reg);
554 if (!of_property_read_u32(node, "ti,bit-shift", &val))
562 if (of_property_read_bool(node, "ti,index-starts-at-one"))
563 *div_flags |= CLK_DIVIDER_ONE_BASED;
565 if (of_property_read_bool(node, "ti,index-power-of-two"))
566 *div_flags |= CLK_DIVIDER_POWER_OF_TWO;
568 if (of_property_read_bool(node, "ti,set-rate-parent"))
569 *flags |= CLK_SET_RATE_PARENT;
571 *table = ti_clk_get_div_table(node);
574 return PTR_ERR(*table);
576 *width = _get_divider_width(node, *table, *div_flags);
582 * of_ti_divider_clk_setup - Setup function for simple div rate clock
583 * @node: device node for this clock
585 * Sets up a basic divider clock.
587 static void __init of_ti_divider_clk_setup(struct device_node *node)
590 const char *parent_name;
592 u8 clk_divider_flags = 0;
595 const struct clk_div_table *table = NULL;
598 parent_name = of_clk_get_parent_name(node, 0);
600 if (ti_clk_divider_populate(node, ®, &table, &flags,
601 &clk_divider_flags, &width, &shift))
604 clk = _register_divider(NULL, node->name, parent_name, flags, reg,
605 shift, width, clk_divider_flags, table);
608 of_clk_add_provider(node, of_clk_src_simple_get, clk);
609 of_ti_clk_autoidle_setup(node);
616 CLK_OF_DECLARE(divider_clk, "ti,divider-clock", of_ti_divider_clk_setup);
618 static void __init of_ti_composite_divider_clk_setup(struct device_node *node)
620 struct clk_divider *div;
623 div = kzalloc(sizeof(*div), GFP_KERNEL);
627 if (ti_clk_divider_populate(node, &div->reg, &div->table, &val,
628 &div->flags, &div->width, &div->shift) < 0)
631 if (!ti_clk_add_component(node, &div->hw, CLK_COMPONENT_TYPE_DIVIDER))
638 CLK_OF_DECLARE(ti_composite_divider_clk, "ti,composite-divider-clock",
639 of_ti_composite_divider_clk_setup);