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
 35static LIST_HEAD(clk_hw_omap_clocks);
 36struct ti_clk_ll_ops *ti_clk_ll_ops;
 37static struct device_node *clocks_node_ptr[CLK_MAX_MEMMAPS];
 38
 39struct ti_clk_features ti_clk_features;
 40
 41struct clk_iomap {
 42	struct regmap *regmap;
 43	void __iomem *mem;
 44};
 45
 46static struct clk_iomap *clk_memmaps[CLK_MAX_MEMMAPS];
 47
 48static 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
 60static 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
 70static 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
 83static 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 */
107int 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 */
131void __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
219struct 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
226static 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 */
237int __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 */
265int 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
294void 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 */
322int __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 */
357void __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 */
379void 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
396static 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 */
407void __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 */
429void __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 */
440const 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 */
455void 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 */
479int 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 */
513struct 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 */
543struct 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 */
570int 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 */
591bool 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}