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