xref: /openbmc/linux/drivers/clk/ti/clk.c (revision 0d3b051a)
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 
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 
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 
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 
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  */
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  */
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;
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 			node = of_get_child_by_name(parent, "clock");
175 			if (!node)
176 				node = of_get_child_by_name(parent, "clk");
177 			of_node_put(parent);
178 		}
179 
180 		clkspec.np = node;
181 		clkspec.args_count = num_args;
182 		for (i = 0; i < num_args; i++) {
183 			ret = kstrtoint(tags[i], i ? 10 : 16, clkspec.args + i);
184 			if (ret) {
185 				pr_warn("Bad tag in %s at %d: %s\n",
186 					c->node_name, i, tags[i]);
187 				of_node_put(node);
188 				return;
189 			}
190 		}
191 		clk = of_clk_get_from_provider(&clkspec);
192 		of_node_put(node);
193 		if (!IS_ERR(clk)) {
194 			c->lk.clk = clk;
195 			clkdev_add(&c->lk);
196 		} else {
197 			if (num_args && !has_clkctrl_data) {
198 				struct device_node *np;
199 
200 				np = of_find_compatible_node(NULL, NULL,
201 							     "ti,clkctrl");
202 				if (np) {
203 					has_clkctrl_data = true;
204 					of_node_put(np);
205 				} else {
206 					clkctrl_nodes_missing = true;
207 
208 					pr_warn("missing clkctrl nodes, please update your dts.\n");
209 					continue;
210 				}
211 			}
212 
213 			pr_warn("failed to lookup clock node %s, ret=%ld\n",
214 				c->node_name, PTR_ERR(clk));
215 		}
216 	}
217 }
218 
219 struct clk_init_item {
220 	struct device_node *node;
221 	void *user;
222 	ti_of_clk_init_cb_t func;
223 	struct list_head link;
224 };
225 
226 static LIST_HEAD(retry_list);
227 
228 /**
229  * ti_clk_retry_init - retries a failed clock init at later phase
230  * @node: device not for the clock
231  * @user: user data pointer
232  * @func: init function to be called for the clock
233  *
234  * Adds a failed clock init to the retry list. The retry list is parsed
235  * once all the other clocks have been initialized.
236  */
237 int __init ti_clk_retry_init(struct device_node *node, void *user,
238 			     ti_of_clk_init_cb_t func)
239 {
240 	struct clk_init_item *retry;
241 
242 	pr_debug("%pOFn: adding to retry list...\n", node);
243 	retry = kzalloc(sizeof(*retry), GFP_KERNEL);
244 	if (!retry)
245 		return -ENOMEM;
246 
247 	retry->node = node;
248 	retry->func = func;
249 	retry->user = user;
250 	list_add(&retry->link, &retry_list);
251 
252 	return 0;
253 }
254 
255 /**
256  * ti_clk_get_reg_addr - get register address for a clock register
257  * @node: device node for the clock
258  * @index: register index from the clock node
259  * @reg: pointer to target register struct
260  *
261  * Builds clock register address from device tree information, and returns
262  * the data via the provided output pointer @reg. Returns 0 on success,
263  * negative error value on failure.
264  */
265 int ti_clk_get_reg_addr(struct device_node *node, int index,
266 			struct clk_omap_reg *reg)
267 {
268 	u32 val;
269 	int i;
270 
271 	for (i = 0; i < CLK_MAX_MEMMAPS; i++) {
272 		if (clocks_node_ptr[i] == node->parent)
273 			break;
274 	}
275 
276 	if (i == CLK_MAX_MEMMAPS) {
277 		pr_err("clk-provider not found for %pOFn!\n", node);
278 		return -ENOENT;
279 	}
280 
281 	reg->index = i;
282 
283 	if (of_property_read_u32_index(node, "reg", index, &val)) {
284 		pr_err("%pOFn must have reg[%d]!\n", node, index);
285 		return -EINVAL;
286 	}
287 
288 	reg->offset = val;
289 	reg->ptr = NULL;
290 
291 	return 0;
292 }
293 
294 void ti_clk_latch(struct clk_omap_reg *reg, s8 shift)
295 {
296 	u32 latch;
297 
298 	if (shift < 0)
299 		return;
300 
301 	latch = 1 << shift;
302 
303 	ti_clk_ll_ops->clk_rmw(latch, latch, reg);
304 	ti_clk_ll_ops->clk_rmw(0, latch, reg);
305 	ti_clk_ll_ops->clk_readl(reg); /* OCP barrier */
306 }
307 
308 /**
309  * omap2_clk_provider_init - init master clock provider
310  * @parent: master node
311  * @index: internal index for clk_reg_ops
312  * @syscon: syscon regmap pointer for accessing clock registers
313  * @mem: iomem pointer for the clock provider memory area, only used if
314  *       syscon is not provided
315  *
316  * Initializes a master clock IP block. This basically sets up the
317  * mapping from clocks node to the memory map index. All the clocks
318  * are then initialized through the common of_clk_init call, and the
319  * clocks will access their memory maps based on the node layout.
320  * Returns 0 in success.
321  */
322 int __init omap2_clk_provider_init(struct device_node *parent, int index,
323 				   struct regmap *syscon, void __iomem *mem)
324 {
325 	struct device_node *clocks;
326 	struct clk_iomap *io;
327 
328 	/* get clocks for this parent */
329 	clocks = of_get_child_by_name(parent, "clocks");
330 	if (!clocks) {
331 		pr_err("%pOFn missing 'clocks' child node.\n", parent);
332 		return -EINVAL;
333 	}
334 
335 	/* add clocks node info */
336 	clocks_node_ptr[index] = clocks;
337 
338 	io = kzalloc(sizeof(*io), GFP_KERNEL);
339 	if (!io)
340 		return -ENOMEM;
341 
342 	io->regmap = syscon;
343 	io->mem = mem;
344 
345 	clk_memmaps[index] = io;
346 
347 	return 0;
348 }
349 
350 /**
351  * omap2_clk_legacy_provider_init - initialize a legacy clock provider
352  * @index: index for the clock provider
353  * @mem: iomem pointer for the clock provider memory area
354  *
355  * Initializes a legacy clock provider memory mapping.
356  */
357 void __init omap2_clk_legacy_provider_init(int index, void __iomem *mem)
358 {
359 	struct clk_iomap *io;
360 
361 	io = memblock_alloc(sizeof(*io), SMP_CACHE_BYTES);
362 	if (!io)
363 		panic("%s: Failed to allocate %zu bytes\n", __func__,
364 		      sizeof(*io));
365 
366 	io->mem = mem;
367 
368 	clk_memmaps[index] = io;
369 }
370 
371 /**
372  * ti_dt_clk_init_retry_clks - init clocks from the retry list
373  *
374  * Initializes any clocks that have failed to initialize before,
375  * reasons being missing parent node(s) during earlier init. This
376  * typically happens only for DPLLs which need to have both of their
377  * parent clocks ready during init.
378  */
379 void ti_dt_clk_init_retry_clks(void)
380 {
381 	struct clk_init_item *retry;
382 	struct clk_init_item *tmp;
383 	int retries = 5;
384 
385 	while (!list_empty(&retry_list) && retries) {
386 		list_for_each_entry_safe(retry, tmp, &retry_list, link) {
387 			pr_debug("retry-init: %pOFn\n", retry->node);
388 			retry->func(retry->user, retry->node);
389 			list_del(&retry->link);
390 			kfree(retry);
391 		}
392 		retries--;
393 	}
394 }
395 
396 static const struct of_device_id simple_clk_match_table[] __initconst = {
397 	{ .compatible = "fixed-clock" },
398 	{ .compatible = "fixed-factor-clock" },
399 	{ }
400 };
401 
402 /**
403  * ti_clk_add_aliases - setup clock aliases
404  *
405  * Sets up any missing clock aliases. No return value.
406  */
407 void __init ti_clk_add_aliases(void)
408 {
409 	struct device_node *np;
410 	struct clk *clk;
411 
412 	for_each_matching_node(np, simple_clk_match_table) {
413 		struct of_phandle_args clkspec;
414 
415 		clkspec.np = np;
416 		clk = of_clk_get_from_provider(&clkspec);
417 
418 		ti_clk_add_alias(NULL, clk, np->name);
419 	}
420 }
421 
422 /**
423  * ti_clk_setup_features - setup clock features flags
424  * @features: features definition to use
425  *
426  * Initializes the clock driver features flags based on platform
427  * provided data. No return value.
428  */
429 void __init ti_clk_setup_features(struct ti_clk_features *features)
430 {
431 	memcpy(&ti_clk_features, features, sizeof(*features));
432 }
433 
434 /**
435  * ti_clk_get_features - get clock driver features flags
436  *
437  * Get TI clock driver features description. Returns a pointer
438  * to the current feature setup.
439  */
440 const struct ti_clk_features *ti_clk_get_features(void)
441 {
442 	return &ti_clk_features;
443 }
444 
445 /**
446  * omap2_clk_enable_init_clocks - prepare & enable a list of clocks
447  * @clk_names: ptr to an array of strings of clock names to enable
448  * @num_clocks: number of clock names in @clk_names
449  *
450  * Prepare and enable a list of clocks, named by @clk_names.  No
451  * return value. XXX Deprecated; only needed until these clocks are
452  * properly claimed and enabled by the drivers or core code that uses
453  * them.  XXX What code disables & calls clk_put on these clocks?
454  */
455 void omap2_clk_enable_init_clocks(const char **clk_names, u8 num_clocks)
456 {
457 	struct clk *init_clk;
458 	int i;
459 
460 	for (i = 0; i < num_clocks; i++) {
461 		init_clk = clk_get(NULL, clk_names[i]);
462 		if (WARN(IS_ERR(init_clk), "could not find init clock %s\n",
463 			 clk_names[i]))
464 			continue;
465 		clk_prepare_enable(init_clk);
466 	}
467 }
468 
469 /**
470  * ti_clk_add_alias - add a clock alias for a TI clock
471  * @dev: device alias for this clock
472  * @clk: clock handle to create alias for
473  * @con: connection ID for this clock
474  *
475  * Creates a clock alias for a TI clock. Allocates the clock lookup entry
476  * and assigns the data to it. Returns 0 if successful, negative error
477  * value otherwise.
478  */
479 int ti_clk_add_alias(struct device *dev, struct clk *clk, const char *con)
480 {
481 	struct clk_lookup *cl;
482 
483 	if (!clk)
484 		return 0;
485 
486 	if (IS_ERR(clk))
487 		return PTR_ERR(clk);
488 
489 	cl = kzalloc(sizeof(*cl), GFP_KERNEL);
490 	if (!cl)
491 		return -ENOMEM;
492 
493 	if (dev)
494 		cl->dev_id = dev_name(dev);
495 	cl->con_id = con;
496 	cl->clk = clk;
497 
498 	clkdev_add(cl);
499 
500 	return 0;
501 }
502 
503 /**
504  * ti_clk_register - register a TI clock to the common clock framework
505  * @dev: device for this clock
506  * @hw: hardware clock handle
507  * @con: connection ID for this clock
508  *
509  * Registers a TI clock to the common clock framework, and adds a clock
510  * alias for it. Returns a handle to the registered clock if successful,
511  * ERR_PTR value in failure.
512  */
513 struct clk *ti_clk_register(struct device *dev, struct clk_hw *hw,
514 			    const char *con)
515 {
516 	struct clk *clk;
517 	int ret;
518 
519 	clk = clk_register(dev, hw);
520 	if (IS_ERR(clk))
521 		return clk;
522 
523 	ret = ti_clk_add_alias(dev, clk, con);
524 	if (ret) {
525 		clk_unregister(clk);
526 		return ERR_PTR(ret);
527 	}
528 
529 	return clk;
530 }
531 
532 /**
533  * ti_clk_register_omap_hw - register a clk_hw_omap to the clock framework
534  * @dev: device for this clock
535  * @hw: hardware clock handle
536  * @con: connection ID for this clock
537  *
538  * Registers a clk_hw_omap clock to the clock framewor, adds a clock alias
539  * for it, and adds the list to the available clk_hw_omap type clocks.
540  * Returns a handle to the registered clock if successful, ERR_PTR value
541  * in failure.
542  */
543 struct clk *ti_clk_register_omap_hw(struct device *dev, struct clk_hw *hw,
544 				    const char *con)
545 {
546 	struct clk *clk;
547 	struct clk_hw_omap *oclk;
548 
549 	clk = ti_clk_register(dev, hw, con);
550 	if (IS_ERR(clk))
551 		return clk;
552 
553 	oclk = to_clk_hw_omap(hw);
554 
555 	list_add(&oclk->node, &clk_hw_omap_clocks);
556 
557 	return clk;
558 }
559 
560 /**
561  * omap2_clk_for_each - call function for each registered clk_hw_omap
562  * @fn: pointer to a callback function
563  *
564  * Call @fn for each registered clk_hw_omap, passing @hw to each
565  * function.  @fn must return 0 for success or any other value for
566  * failure.  If @fn returns non-zero, the iteration across clocks
567  * will stop and the non-zero return value will be passed to the
568  * caller of omap2_clk_for_each().
569  */
570 int omap2_clk_for_each(int (*fn)(struct clk_hw_omap *hw))
571 {
572 	int ret;
573 	struct clk_hw_omap *hw;
574 
575 	list_for_each_entry(hw, &clk_hw_omap_clocks, node) {
576 		ret = (*fn)(hw);
577 		if (ret)
578 			break;
579 	}
580 
581 	return ret;
582 }
583 
584 /**
585  * omap2_clk_is_hw_omap - check if the provided clk_hw is OMAP clock
586  * @hw: clk_hw to check if it is an omap clock or not
587  *
588  * Checks if the provided clk_hw is OMAP clock or not. Returns true if
589  * it is, false otherwise.
590  */
591 bool omap2_clk_is_hw_omap(struct clk_hw *hw)
592 {
593 	struct clk_hw_omap *oclk;
594 
595 	list_for_each_entry(oclk, &clk_hw_omap_clocks, node) {
596 		if (&oclk->hw == hw)
597 			return true;
598 	}
599 
600 	return false;
601 }
602