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1 /*
2  * TI clock support
3  *
4  * Copyright (C) 2013 Texas Instruments, Inc.
5  *
6  * Tero Kristo <t-kristo@ti.com>
7  *
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.
11  *
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.
16  */
17 
18 #include <linux/clk.h>
19 #include <linux/clk-provider.h>
20 #include <linux/clkdev.h>
21 #include <linux/clk/ti.h>
22 #include <linux/io.h>
23 #include <linux/of.h>
24 #include <linux/of_address.h>
25 #include <linux/list.h>
26 #include <linux/regmap.h>
27 #include <linux/memblock.h>
28 #include <linux/device.h>
29 
30 #include "clock.h"
31 
32 #undef pr_fmt
33 #define pr_fmt(fmt) "%s: " fmt, __func__
34 
35 static LIST_HEAD(clk_hw_omap_clocks);
36 struct ti_clk_ll_ops *ti_clk_ll_ops;
37 static struct device_node *clocks_node_ptr[CLK_MAX_MEMMAPS];
38 
39 struct ti_clk_features ti_clk_features;
40 
41 struct clk_iomap {
42 	struct regmap *regmap;
43 	void __iomem *mem;
44 };
45 
46 static struct clk_iomap *clk_memmaps[CLK_MAX_MEMMAPS];
47 
clk_memmap_writel(u32 val,const struct clk_omap_reg * reg)48 static void clk_memmap_writel(u32 val, const struct clk_omap_reg *reg)
49 {
50 	struct clk_iomap *io = clk_memmaps[reg->index];
51 
52 	if (reg->ptr)
53 		writel_relaxed(val, reg->ptr);
54 	else if (io->regmap)
55 		regmap_write(io->regmap, reg->offset, val);
56 	else
57 		writel_relaxed(val, io->mem + reg->offset);
58 }
59 
_clk_rmw(u32 val,u32 mask,void __iomem * ptr)60 static void _clk_rmw(u32 val, u32 mask, void __iomem *ptr)
61 {
62 	u32 v;
63 
64 	v = readl_relaxed(ptr);
65 	v &= ~mask;
66 	v |= val;
67 	writel_relaxed(v, ptr);
68 }
69 
clk_memmap_rmw(u32 val,u32 mask,const struct clk_omap_reg * reg)70 static void clk_memmap_rmw(u32 val, u32 mask, const struct clk_omap_reg *reg)
71 {
72 	struct clk_iomap *io = clk_memmaps[reg->index];
73 
74 	if (reg->ptr) {
75 		_clk_rmw(val, mask, reg->ptr);
76 	} else if (io->regmap) {
77 		regmap_update_bits(io->regmap, reg->offset, mask, val);
78 	} else {
79 		_clk_rmw(val, mask, io->mem + reg->offset);
80 	}
81 }
82 
clk_memmap_readl(const struct clk_omap_reg * reg)83 static u32 clk_memmap_readl(const struct clk_omap_reg *reg)
84 {
85 	u32 val;
86 	struct clk_iomap *io = clk_memmaps[reg->index];
87 
88 	if (reg->ptr)
89 		val = readl_relaxed(reg->ptr);
90 	else if (io->regmap)
91 		regmap_read(io->regmap, reg->offset, &val);
92 	else
93 		val = readl_relaxed(io->mem + reg->offset);
94 
95 	return val;
96 }
97 
98 /**
99  * ti_clk_setup_ll_ops - setup low level clock operations
100  * @ops: low level clock ops descriptor
101  *
102  * Sets up low level clock operations for TI clock driver. This is used
103  * to provide various callbacks for the clock driver towards platform
104  * specific code. Returns 0 on success, -EBUSY if ll_ops have been
105  * registered already.
106  */
ti_clk_setup_ll_ops(struct ti_clk_ll_ops * ops)107 int ti_clk_setup_ll_ops(struct ti_clk_ll_ops *ops)
108 {
109 	if (ti_clk_ll_ops) {
110 		pr_err("Attempt to register ll_ops multiple times.\n");
111 		return -EBUSY;
112 	}
113 
114 	ti_clk_ll_ops = ops;
115 	ops->clk_readl = clk_memmap_readl;
116 	ops->clk_writel = clk_memmap_writel;
117 	ops->clk_rmw = clk_memmap_rmw;
118 
119 	return 0;
120 }
121 
122 /**
123  * ti_dt_clocks_register - register DT alias clocks during boot
124  * @oclks: list of clocks to register
125  *
126  * Register alias or non-standard DT clock entries during boot. By
127  * default, DT clocks are found based on their node name. If any
128  * additional con-id / dev-id -> clock mapping is required, use this
129  * function to list these.
130  */
ti_dt_clocks_register(struct ti_dt_clk oclks[])131 void __init ti_dt_clocks_register(struct ti_dt_clk oclks[])
132 {
133 	struct ti_dt_clk *c;
134 	struct device_node *node, *parent, *child;
135 	struct clk *clk;
136 	struct of_phandle_args clkspec;
137 	char buf[64];
138 	char *ptr;
139 	char *tags[2];
140 	int i;
141 	int num_args;
142 	int ret;
143 	static bool clkctrl_nodes_missing;
144 	static bool has_clkctrl_data;
145 	static bool compat_mode;
146 
147 	compat_mode = ti_clk_get_features()->flags & TI_CLK_CLKCTRL_COMPAT;
148 
149 	for (c = oclks; c->node_name != NULL; c++) {
150 		strcpy(buf, c->node_name);
151 		ptr = buf;
152 		for (i = 0; i < 2; i++)
153 			tags[i] = NULL;
154 		num_args = 0;
155 		while (*ptr) {
156 			if (*ptr == ':') {
157 				if (num_args >= 2) {
158 					pr_warn("Bad number of tags on %s\n",
159 						c->node_name);
160 					return;
161 				}
162 				tags[num_args++] = ptr + 1;
163 				*ptr = 0;
164 			}
165 			ptr++;
166 		}
167 
168 		if (num_args && clkctrl_nodes_missing)
169 			continue;
170 
171 		node = of_find_node_by_name(NULL, buf);
172 		if (num_args && compat_mode) {
173 			parent = node;
174 			child = of_get_child_by_name(parent, "clock");
175 			if (!child)
176 				child = of_get_child_by_name(parent, "clk");
177 			if (child) {
178 				of_node_put(parent);
179 				node = child;
180 			}
181 		}
182 
183 		clkspec.np = node;
184 		clkspec.args_count = num_args;
185 		for (i = 0; i < num_args; i++) {
186 			ret = kstrtoint(tags[i], i ? 10 : 16, clkspec.args + i);
187 			if (ret) {
188 				pr_warn("Bad tag in %s at %d: %s\n",
189 					c->node_name, i, tags[i]);
190 				of_node_put(node);
191 				return;
192 			}
193 		}
194 		clk = of_clk_get_from_provider(&clkspec);
195 		of_node_put(node);
196 		if (!IS_ERR(clk)) {
197 			c->lk.clk = clk;
198 			clkdev_add(&c->lk);
199 		} else {
200 			if (num_args && !has_clkctrl_data) {
201 				struct device_node *np;
202 
203 				np = of_find_compatible_node(NULL, NULL,
204 							     "ti,clkctrl");
205 				if (np) {
206 					has_clkctrl_data = true;
207 					of_node_put(np);
208 				} else {
209 					clkctrl_nodes_missing = true;
210 
211 					pr_warn("missing clkctrl nodes, please update your dts.\n");
212 					continue;
213 				}
214 			}
215 
216 			pr_warn("failed to lookup clock node %s, ret=%ld\n",
217 				c->node_name, PTR_ERR(clk));
218 		}
219 	}
220 }
221 
222 struct clk_init_item {
223 	struct device_node *node;
224 	void *user;
225 	ti_of_clk_init_cb_t func;
226 	struct list_head link;
227 };
228 
229 static LIST_HEAD(retry_list);
230 
231 /**
232  * ti_clk_retry_init - retries a failed clock init at later phase
233  * @node: device not for the clock
234  * @user: user data pointer
235  * @func: init function to be called for the clock
236  *
237  * Adds a failed clock init to the retry list. The retry list is parsed
238  * once all the other clocks have been initialized.
239  */
ti_clk_retry_init(struct device_node * node,void * user,ti_of_clk_init_cb_t func)240 int __init ti_clk_retry_init(struct device_node *node, void *user,
241 			     ti_of_clk_init_cb_t func)
242 {
243 	struct clk_init_item *retry;
244 
245 	pr_debug("%pOFn: adding to retry list...\n", node);
246 	retry = kzalloc(sizeof(*retry), GFP_KERNEL);
247 	if (!retry)
248 		return -ENOMEM;
249 
250 	retry->node = node;
251 	retry->func = func;
252 	retry->user = user;
253 	list_add(&retry->link, &retry_list);
254 
255 	return 0;
256 }
257 
258 /**
259  * ti_clk_get_reg_addr - get register address for a clock register
260  * @node: device node for the clock
261  * @index: register index from the clock node
262  * @reg: pointer to target register struct
263  *
264  * Builds clock register address from device tree information, and returns
265  * the data via the provided output pointer @reg. Returns 0 on success,
266  * negative error value on failure.
267  */
ti_clk_get_reg_addr(struct device_node * node,int index,struct clk_omap_reg * reg)268 int ti_clk_get_reg_addr(struct device_node *node, int index,
269 			struct clk_omap_reg *reg)
270 {
271 	u32 val;
272 	int i;
273 
274 	for (i = 0; i < CLK_MAX_MEMMAPS; i++) {
275 		if (clocks_node_ptr[i] == node->parent)
276 			break;
277 	}
278 
279 	if (i == CLK_MAX_MEMMAPS) {
280 		pr_err("clk-provider not found for %pOFn!\n", node);
281 		return -ENOENT;
282 	}
283 
284 	reg->index = i;
285 
286 	if (of_property_read_u32_index(node, "reg", index, &val)) {
287 		pr_err("%pOFn must have reg[%d]!\n", node, index);
288 		return -EINVAL;
289 	}
290 
291 	reg->offset = val;
292 	reg->ptr = NULL;
293 
294 	return 0;
295 }
296 
ti_clk_latch(struct clk_omap_reg * reg,s8 shift)297 void ti_clk_latch(struct clk_omap_reg *reg, s8 shift)
298 {
299 	u32 latch;
300 
301 	if (shift < 0)
302 		return;
303 
304 	latch = 1 << shift;
305 
306 	ti_clk_ll_ops->clk_rmw(latch, latch, reg);
307 	ti_clk_ll_ops->clk_rmw(0, latch, reg);
308 	ti_clk_ll_ops->clk_readl(reg); /* OCP barrier */
309 }
310 
311 /**
312  * omap2_clk_provider_init - init master clock provider
313  * @parent: master node
314  * @index: internal index for clk_reg_ops
315  * @syscon: syscon regmap pointer for accessing clock registers
316  * @mem: iomem pointer for the clock provider memory area, only used if
317  *       syscon is not provided
318  *
319  * Initializes a master clock IP block. This basically sets up the
320  * mapping from clocks node to the memory map index. All the clocks
321  * are then initialized through the common of_clk_init call, and the
322  * clocks will access their memory maps based on the node layout.
323  * Returns 0 in success.
324  */
omap2_clk_provider_init(struct device_node * parent,int index,struct regmap * syscon,void __iomem * mem)325 int __init omap2_clk_provider_init(struct device_node *parent, int index,
326 				   struct regmap *syscon, void __iomem *mem)
327 {
328 	struct device_node *clocks;
329 	struct clk_iomap *io;
330 
331 	/* get clocks for this parent */
332 	clocks = of_get_child_by_name(parent, "clocks");
333 	if (!clocks) {
334 		pr_err("%pOFn missing 'clocks' child node.\n", parent);
335 		return -EINVAL;
336 	}
337 
338 	/* add clocks node info */
339 	clocks_node_ptr[index] = clocks;
340 
341 	io = kzalloc(sizeof(*io), GFP_KERNEL);
342 	if (!io)
343 		return -ENOMEM;
344 
345 	io->regmap = syscon;
346 	io->mem = mem;
347 
348 	clk_memmaps[index] = io;
349 
350 	return 0;
351 }
352 
353 /**
354  * omap2_clk_legacy_provider_init - initialize a legacy clock provider
355  * @index: index for the clock provider
356  * @mem: iomem pointer for the clock provider memory area
357  *
358  * Initializes a legacy clock provider memory mapping.
359  */
omap2_clk_legacy_provider_init(int index,void __iomem * mem)360 void __init omap2_clk_legacy_provider_init(int index, void __iomem *mem)
361 {
362 	struct clk_iomap *io;
363 
364 	io = memblock_alloc(sizeof(*io), SMP_CACHE_BYTES);
365 	if (!io)
366 		panic("%s: Failed to allocate %zu bytes\n", __func__,
367 		      sizeof(*io));
368 
369 	io->mem = mem;
370 
371 	clk_memmaps[index] = io;
372 }
373 
374 /**
375  * ti_dt_clk_init_retry_clks - init clocks from the retry list
376  *
377  * Initializes any clocks that have failed to initialize before,
378  * reasons being missing parent node(s) during earlier init. This
379  * typically happens only for DPLLs which need to have both of their
380  * parent clocks ready during init.
381  */
ti_dt_clk_init_retry_clks(void)382 void ti_dt_clk_init_retry_clks(void)
383 {
384 	struct clk_init_item *retry;
385 	struct clk_init_item *tmp;
386 	int retries = 5;
387 
388 	while (!list_empty(&retry_list) && retries) {
389 		list_for_each_entry_safe(retry, tmp, &retry_list, link) {
390 			pr_debug("retry-init: %pOFn\n", retry->node);
391 			retry->func(retry->user, retry->node);
392 			list_del(&retry->link);
393 			kfree(retry);
394 		}
395 		retries--;
396 	}
397 }
398 
399 static const struct of_device_id simple_clk_match_table[] __initconst = {
400 	{ .compatible = "fixed-clock" },
401 	{ .compatible = "fixed-factor-clock" },
402 	{ }
403 };
404 
405 /**
406  * ti_clk_add_aliases - setup clock aliases
407  *
408  * Sets up any missing clock aliases. No return value.
409  */
ti_clk_add_aliases(void)410 void __init ti_clk_add_aliases(void)
411 {
412 	struct device_node *np;
413 	struct clk *clk;
414 
415 	for_each_matching_node(np, simple_clk_match_table) {
416 		struct of_phandle_args clkspec;
417 
418 		clkspec.np = np;
419 		clk = of_clk_get_from_provider(&clkspec);
420 
421 		ti_clk_add_alias(NULL, clk, np->name);
422 	}
423 }
424 
425 /**
426  * ti_clk_setup_features - setup clock features flags
427  * @features: features definition to use
428  *
429  * Initializes the clock driver features flags based on platform
430  * provided data. No return value.
431  */
ti_clk_setup_features(struct ti_clk_features * features)432 void __init ti_clk_setup_features(struct ti_clk_features *features)
433 {
434 	memcpy(&ti_clk_features, features, sizeof(*features));
435 }
436 
437 /**
438  * ti_clk_get_features - get clock driver features flags
439  *
440  * Get TI clock driver features description. Returns a pointer
441  * to the current feature setup.
442  */
ti_clk_get_features(void)443 const struct ti_clk_features *ti_clk_get_features(void)
444 {
445 	return &ti_clk_features;
446 }
447 
448 /**
449  * omap2_clk_enable_init_clocks - prepare & enable a list of clocks
450  * @clk_names: ptr to an array of strings of clock names to enable
451  * @num_clocks: number of clock names in @clk_names
452  *
453  * Prepare and enable a list of clocks, named by @clk_names.  No
454  * return value. XXX Deprecated; only needed until these clocks are
455  * properly claimed and enabled by the drivers or core code that uses
456  * them.  XXX What code disables & calls clk_put on these clocks?
457  */
omap2_clk_enable_init_clocks(const char ** clk_names,u8 num_clocks)458 void omap2_clk_enable_init_clocks(const char **clk_names, u8 num_clocks)
459 {
460 	struct clk *init_clk;
461 	int i;
462 
463 	for (i = 0; i < num_clocks; i++) {
464 		init_clk = clk_get(NULL, clk_names[i]);
465 		if (WARN(IS_ERR(init_clk), "could not find init clock %s\n",
466 			 clk_names[i]))
467 			continue;
468 		clk_prepare_enable(init_clk);
469 	}
470 }
471 
472 /**
473  * ti_clk_add_alias - add a clock alias for a TI clock
474  * @dev: device alias for this clock
475  * @clk: clock handle to create alias for
476  * @con: connection ID for this clock
477  *
478  * Creates a clock alias for a TI clock. Allocates the clock lookup entry
479  * and assigns the data to it. Returns 0 if successful, negative error
480  * value otherwise.
481  */
ti_clk_add_alias(struct device * dev,struct clk * clk,const char * con)482 int ti_clk_add_alias(struct device *dev, struct clk *clk, const char *con)
483 {
484 	struct clk_lookup *cl;
485 
486 	if (!clk)
487 		return 0;
488 
489 	if (IS_ERR(clk))
490 		return PTR_ERR(clk);
491 
492 	cl = kzalloc(sizeof(*cl), GFP_KERNEL);
493 	if (!cl)
494 		return -ENOMEM;
495 
496 	if (dev)
497 		cl->dev_id = dev_name(dev);
498 	cl->con_id = con;
499 	cl->clk = clk;
500 
501 	clkdev_add(cl);
502 
503 	return 0;
504 }
505 
506 /**
507  * ti_clk_register - register a TI clock to the common clock framework
508  * @dev: device for this clock
509  * @hw: hardware clock handle
510  * @con: connection ID for this clock
511  *
512  * Registers a TI clock to the common clock framework, and adds a clock
513  * alias for it. Returns a handle to the registered clock if successful,
514  * ERR_PTR value in failure.
515  */
ti_clk_register(struct device * dev,struct clk_hw * hw,const char * con)516 struct clk *ti_clk_register(struct device *dev, struct clk_hw *hw,
517 			    const char *con)
518 {
519 	struct clk *clk;
520 	int ret;
521 
522 	clk = clk_register(dev, hw);
523 	if (IS_ERR(clk))
524 		return clk;
525 
526 	ret = ti_clk_add_alias(dev, clk, con);
527 	if (ret) {
528 		clk_unregister(clk);
529 		return ERR_PTR(ret);
530 	}
531 
532 	return clk;
533 }
534 
535 /**
536  * ti_clk_register_omap_hw - register a clk_hw_omap to the clock framework
537  * @dev: device for this clock
538  * @hw: hardware clock handle
539  * @con: connection ID for this clock
540  *
541  * Registers a clk_hw_omap clock to the clock framewor, adds a clock alias
542  * for it, and adds the list to the available clk_hw_omap type clocks.
543  * Returns a handle to the registered clock if successful, ERR_PTR value
544  * in failure.
545  */
ti_clk_register_omap_hw(struct device * dev,struct clk_hw * hw,const char * con)546 struct clk *ti_clk_register_omap_hw(struct device *dev, struct clk_hw *hw,
547 				    const char *con)
548 {
549 	struct clk *clk;
550 	struct clk_hw_omap *oclk;
551 
552 	clk = ti_clk_register(dev, hw, con);
553 	if (IS_ERR(clk))
554 		return clk;
555 
556 	oclk = to_clk_hw_omap(hw);
557 
558 	list_add(&oclk->node, &clk_hw_omap_clocks);
559 
560 	return clk;
561 }
562 
563 /**
564  * omap2_clk_for_each - call function for each registered clk_hw_omap
565  * @fn: pointer to a callback function
566  *
567  * Call @fn for each registered clk_hw_omap, passing @hw to each
568  * function.  @fn must return 0 for success or any other value for
569  * failure.  If @fn returns non-zero, the iteration across clocks
570  * will stop and the non-zero return value will be passed to the
571  * caller of omap2_clk_for_each().
572  */
omap2_clk_for_each(int (* fn)(struct clk_hw_omap * hw))573 int omap2_clk_for_each(int (*fn)(struct clk_hw_omap *hw))
574 {
575 	int ret;
576 	struct clk_hw_omap *hw;
577 
578 	list_for_each_entry(hw, &clk_hw_omap_clocks, node) {
579 		ret = (*fn)(hw);
580 		if (ret)
581 			break;
582 	}
583 
584 	return ret;
585 }
586 
587 /**
588  * omap2_clk_is_hw_omap - check if the provided clk_hw is OMAP clock
589  * @hw: clk_hw to check if it is an omap clock or not
590  *
591  * Checks if the provided clk_hw is OMAP clock or not. Returns true if
592  * it is, false otherwise.
593  */
omap2_clk_is_hw_omap(struct clk_hw * hw)594 bool omap2_clk_is_hw_omap(struct clk_hw *hw)
595 {
596 	struct clk_hw_omap *oclk;
597 
598 	list_for_each_entry(oclk, &clk_hw_omap_clocks, node) {
599 		if (&oclk->hw == hw)
600 			return true;
601 	}
602 
603 	return false;
604 }
605