xref: /openbmc/linux/drivers/clk/samsung/clk.c (revision 3d9b448b)
1 /*
2  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
3  * Copyright (c) 2013 Linaro Ltd.
4  * Author: Thomas Abraham <thomas.ab@samsung.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This file includes utility functions to register clocks to common
11  * clock framework for Samsung platforms.
12 */
13 
14 #include <linux/of_address.h>
15 #include <linux/syscore_ops.h>
16 
17 #include "clk.h"
18 
19 static LIST_HEAD(clock_reg_cache_list);
20 
21 void samsung_clk_save(void __iomem *base,
22 				    struct samsung_clk_reg_dump *rd,
23 				    unsigned int num_regs)
24 {
25 	for (; num_regs > 0; --num_regs, ++rd)
26 		rd->value = readl(base + rd->offset);
27 }
28 
29 void samsung_clk_restore(void __iomem *base,
30 				      const struct samsung_clk_reg_dump *rd,
31 				      unsigned int num_regs)
32 {
33 	for (; num_regs > 0; --num_regs, ++rd)
34 		writel(rd->value, base + rd->offset);
35 }
36 
37 struct samsung_clk_reg_dump *samsung_clk_alloc_reg_dump(
38 						const unsigned long *rdump,
39 						unsigned long nr_rdump)
40 {
41 	struct samsung_clk_reg_dump *rd;
42 	unsigned int i;
43 
44 	rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);
45 	if (!rd)
46 		return NULL;
47 
48 	for (i = 0; i < nr_rdump; ++i)
49 		rd[i].offset = rdump[i];
50 
51 	return rd;
52 }
53 
54 /* setup the essentials required to support clock lookup using ccf */
55 struct samsung_clk_provider *__init samsung_clk_init(struct device_node *np,
56 			void __iomem *base, unsigned long nr_clks)
57 {
58 	struct samsung_clk_provider *ctx;
59 	struct clk **clk_table;
60 	int i;
61 
62 	ctx = kzalloc(sizeof(struct samsung_clk_provider), GFP_KERNEL);
63 	if (!ctx)
64 		panic("could not allocate clock provider context.\n");
65 
66 	clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
67 	if (!clk_table)
68 		panic("could not allocate clock lookup table\n");
69 
70 	for (i = 0; i < nr_clks; ++i)
71 		clk_table[i] = ERR_PTR(-ENOENT);
72 
73 	ctx->reg_base = base;
74 	ctx->clk_data.clks = clk_table;
75 	ctx->clk_data.clk_num = nr_clks;
76 	spin_lock_init(&ctx->lock);
77 
78 	return ctx;
79 }
80 
81 void __init samsung_clk_of_add_provider(struct device_node *np,
82 				struct samsung_clk_provider *ctx)
83 {
84 	if (np) {
85 		if (of_clk_add_provider(np, of_clk_src_onecell_get,
86 					&ctx->clk_data))
87 			panic("could not register clk provider\n");
88 	}
89 }
90 
91 /* add a clock instance to the clock lookup table used for dt based lookup */
92 void samsung_clk_add_lookup(struct samsung_clk_provider *ctx, struct clk *clk,
93 				unsigned int id)
94 {
95 	if (ctx->clk_data.clks && id)
96 		ctx->clk_data.clks[id] = clk;
97 }
98 
99 /* register a list of aliases */
100 void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx,
101 				struct samsung_clock_alias *list,
102 				unsigned int nr_clk)
103 {
104 	struct clk *clk;
105 	unsigned int idx, ret;
106 
107 	if (!ctx->clk_data.clks) {
108 		pr_err("%s: clock table missing\n", __func__);
109 		return;
110 	}
111 
112 	for (idx = 0; idx < nr_clk; idx++, list++) {
113 		if (!list->id) {
114 			pr_err("%s: clock id missing for index %d\n", __func__,
115 				idx);
116 			continue;
117 		}
118 
119 		clk = ctx->clk_data.clks[list->id];
120 		if (!clk) {
121 			pr_err("%s: failed to find clock %d\n", __func__,
122 				list->id);
123 			continue;
124 		}
125 
126 		ret = clk_register_clkdev(clk, list->alias, list->dev_name);
127 		if (ret)
128 			pr_err("%s: failed to register lookup %s\n",
129 					__func__, list->alias);
130 	}
131 }
132 
133 /* register a list of fixed clocks */
134 void __init samsung_clk_register_fixed_rate(struct samsung_clk_provider *ctx,
135 		struct samsung_fixed_rate_clock *list, unsigned int nr_clk)
136 {
137 	struct clk *clk;
138 	unsigned int idx, ret;
139 
140 	for (idx = 0; idx < nr_clk; idx++, list++) {
141 		clk = clk_register_fixed_rate(NULL, list->name,
142 			list->parent_name, list->flags, list->fixed_rate);
143 		if (IS_ERR(clk)) {
144 			pr_err("%s: failed to register clock %s\n", __func__,
145 				list->name);
146 			continue;
147 		}
148 
149 		samsung_clk_add_lookup(ctx, clk, list->id);
150 
151 		/*
152 		 * Unconditionally add a clock lookup for the fixed rate clocks.
153 		 * There are not many of these on any of Samsung platforms.
154 		 */
155 		ret = clk_register_clkdev(clk, list->name, NULL);
156 		if (ret)
157 			pr_err("%s: failed to register clock lookup for %s",
158 				__func__, list->name);
159 	}
160 }
161 
162 /* register a list of fixed factor clocks */
163 void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx,
164 		struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
165 {
166 	struct clk *clk;
167 	unsigned int idx;
168 
169 	for (idx = 0; idx < nr_clk; idx++, list++) {
170 		clk = clk_register_fixed_factor(NULL, list->name,
171 			list->parent_name, list->flags, list->mult, list->div);
172 		if (IS_ERR(clk)) {
173 			pr_err("%s: failed to register clock %s\n", __func__,
174 				list->name);
175 			continue;
176 		}
177 
178 		samsung_clk_add_lookup(ctx, clk, list->id);
179 	}
180 }
181 
182 /* register a list of mux clocks */
183 void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx,
184 				struct samsung_mux_clock *list,
185 				unsigned int nr_clk)
186 {
187 	struct clk *clk;
188 	unsigned int idx, ret;
189 
190 	for (idx = 0; idx < nr_clk; idx++, list++) {
191 		clk = clk_register_mux(NULL, list->name, list->parent_names,
192 			list->num_parents, list->flags,
193 			ctx->reg_base + list->offset,
194 			list->shift, list->width, list->mux_flags, &ctx->lock);
195 		if (IS_ERR(clk)) {
196 			pr_err("%s: failed to register clock %s\n", __func__,
197 				list->name);
198 			continue;
199 		}
200 
201 		samsung_clk_add_lookup(ctx, clk, list->id);
202 
203 		/* register a clock lookup only if a clock alias is specified */
204 		if (list->alias) {
205 			ret = clk_register_clkdev(clk, list->alias,
206 						list->dev_name);
207 			if (ret)
208 				pr_err("%s: failed to register lookup %s\n",
209 						__func__, list->alias);
210 		}
211 	}
212 }
213 
214 /* register a list of div clocks */
215 void __init samsung_clk_register_div(struct samsung_clk_provider *ctx,
216 				struct samsung_div_clock *list,
217 				unsigned int nr_clk)
218 {
219 	struct clk *clk;
220 	unsigned int idx, ret;
221 
222 	for (idx = 0; idx < nr_clk; idx++, list++) {
223 		if (list->table)
224 			clk = clk_register_divider_table(NULL, list->name,
225 				list->parent_name, list->flags,
226 				ctx->reg_base + list->offset,
227 				list->shift, list->width, list->div_flags,
228 				list->table, &ctx->lock);
229 		else
230 			clk = clk_register_divider(NULL, list->name,
231 				list->parent_name, list->flags,
232 				ctx->reg_base + list->offset, list->shift,
233 				list->width, list->div_flags, &ctx->lock);
234 		if (IS_ERR(clk)) {
235 			pr_err("%s: failed to register clock %s\n", __func__,
236 				list->name);
237 			continue;
238 		}
239 
240 		samsung_clk_add_lookup(ctx, clk, list->id);
241 
242 		/* register a clock lookup only if a clock alias is specified */
243 		if (list->alias) {
244 			ret = clk_register_clkdev(clk, list->alias,
245 						list->dev_name);
246 			if (ret)
247 				pr_err("%s: failed to register lookup %s\n",
248 						__func__, list->alias);
249 		}
250 	}
251 }
252 
253 /* register a list of gate clocks */
254 void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx,
255 				struct samsung_gate_clock *list,
256 				unsigned int nr_clk)
257 {
258 	struct clk *clk;
259 	unsigned int idx, ret;
260 
261 	for (idx = 0; idx < nr_clk; idx++, list++) {
262 		clk = clk_register_gate(NULL, list->name, list->parent_name,
263 				list->flags, ctx->reg_base + list->offset,
264 				list->bit_idx, list->gate_flags, &ctx->lock);
265 		if (IS_ERR(clk)) {
266 			pr_err("%s: failed to register clock %s\n", __func__,
267 				list->name);
268 			continue;
269 		}
270 
271 		/* register a clock lookup only if a clock alias is specified */
272 		if (list->alias) {
273 			ret = clk_register_clkdev(clk, list->alias,
274 							list->dev_name);
275 			if (ret)
276 				pr_err("%s: failed to register lookup %s\n",
277 					__func__, list->alias);
278 		}
279 
280 		samsung_clk_add_lookup(ctx, clk, list->id);
281 	}
282 }
283 
284 /*
285  * obtain the clock speed of all external fixed clock sources from device
286  * tree and register it
287  */
288 void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx,
289 			struct samsung_fixed_rate_clock *fixed_rate_clk,
290 			unsigned int nr_fixed_rate_clk,
291 			const struct of_device_id *clk_matches)
292 {
293 	const struct of_device_id *match;
294 	struct device_node *clk_np;
295 	u32 freq;
296 
297 	for_each_matching_node_and_match(clk_np, clk_matches, &match) {
298 		if (of_property_read_u32(clk_np, "clock-frequency", &freq))
299 			continue;
300 		fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq;
301 	}
302 	samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk);
303 }
304 
305 /* utility function to get the rate of a specified clock */
306 unsigned long _get_rate(const char *clk_name)
307 {
308 	struct clk *clk;
309 
310 	clk = __clk_lookup(clk_name);
311 	if (!clk) {
312 		pr_err("%s: could not find clock %s\n", __func__, clk_name);
313 		return 0;
314 	}
315 
316 	return clk_get_rate(clk);
317 }
318 
319 #ifdef CONFIG_PM_SLEEP
320 static int samsung_clk_suspend(void)
321 {
322 	struct samsung_clock_reg_cache *reg_cache;
323 
324 	list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
325 		samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
326 				reg_cache->rd_num);
327 	return 0;
328 }
329 
330 static void samsung_clk_resume(void)
331 {
332 	struct samsung_clock_reg_cache *reg_cache;
333 
334 	list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
335 		samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
336 				reg_cache->rd_num);
337 }
338 
339 static struct syscore_ops samsung_clk_syscore_ops = {
340 	.suspend = samsung_clk_suspend,
341 	.resume = samsung_clk_resume,
342 };
343 
344 static void samsung_clk_sleep_init(void __iomem *reg_base,
345 		const unsigned long *rdump,
346 		unsigned long nr_rdump)
347 {
348 	struct samsung_clock_reg_cache *reg_cache;
349 
350 	reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
351 			GFP_KERNEL);
352 	if (!reg_cache)
353 		panic("could not allocate register reg_cache.\n");
354 	reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);
355 
356 	if (!reg_cache->rdump)
357 		panic("could not allocate register dump storage.\n");
358 
359 	if (list_empty(&clock_reg_cache_list))
360 		register_syscore_ops(&samsung_clk_syscore_ops);
361 
362 	reg_cache->reg_base = reg_base;
363 	reg_cache->rd_num = nr_rdump;
364 	list_add_tail(&reg_cache->node, &clock_reg_cache_list);
365 }
366 
367 #else
368 static void samsung_clk_sleep_init(void __iomem *reg_base,
369 		const unsigned long *rdump,
370 		unsigned long nr_rdump) {}
371 #endif
372 
373 /*
374  * Common function which registers plls, muxes, dividers and gates
375  * for each CMU. It also add CMU register list to register cache.
376  */
377 struct samsung_clk_provider * __init samsung_cmu_register_one(
378 			struct device_node *np,
379 			struct samsung_cmu_info *cmu)
380 {
381 	void __iomem *reg_base;
382 	struct samsung_clk_provider *ctx;
383 
384 	reg_base = of_iomap(np, 0);
385 	if (!reg_base) {
386 		panic("%s: failed to map registers\n", __func__);
387 		return NULL;
388 	}
389 
390 	ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids);
391 	if (!ctx) {
392 		panic("%s: unable to alllocate ctx\n", __func__);
393 		return ctx;
394 	}
395 
396 	if (cmu->pll_clks)
397 		samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks,
398 			reg_base);
399 	if (cmu->mux_clks)
400 		samsung_clk_register_mux(ctx, cmu->mux_clks,
401 			cmu->nr_mux_clks);
402 	if (cmu->div_clks)
403 		samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
404 	if (cmu->gate_clks)
405 		samsung_clk_register_gate(ctx, cmu->gate_clks,
406 			cmu->nr_gate_clks);
407 	if (cmu->fixed_clks)
408 		samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
409 			cmu->nr_fixed_clks);
410 	if (cmu->fixed_factor_clks)
411 		samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
412 			cmu->nr_fixed_factor_clks);
413 	if (cmu->clk_regs)
414 		samsung_clk_sleep_init(reg_base, cmu->clk_regs,
415 			cmu->nr_clk_regs);
416 
417 	samsung_clk_of_add_provider(np, ctx);
418 
419 	return ctx;
420 }
421