xref: /linux/drivers/clk/samsung/clk.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
4  * Copyright (c) 2013 Linaro Ltd.
5  * Author: Thomas Abraham <thomas.ab@samsung.com>
6  *
7  * This file includes utility functions to register clocks to common
8  * clock framework for Samsung platforms.
9 */
10 
11 #include <linux/slab.h>
12 #include <linux/clkdev.h>
13 #include <linux/clk.h>
14 #include <linux/clk-provider.h>
15 #include <linux/io.h>
16 #include <linux/of_address.h>
17 #include <linux/syscore_ops.h>
18 
19 #include "clk.h"
20 
21 static LIST_HEAD(clock_reg_cache_list);
22 
23 void samsung_clk_save(void __iomem *base,
24 				    struct samsung_clk_reg_dump *rd,
25 				    unsigned int num_regs)
26 {
27 	for (; num_regs > 0; --num_regs, ++rd)
28 		rd->value = readl(base + rd->offset);
29 }
30 
31 void samsung_clk_restore(void __iomem *base,
32 				      const struct samsung_clk_reg_dump *rd,
33 				      unsigned int num_regs)
34 {
35 	for (; num_regs > 0; --num_regs, ++rd)
36 		writel(rd->value, base + rd->offset);
37 }
38 
39 struct samsung_clk_reg_dump *samsung_clk_alloc_reg_dump(
40 						const unsigned long *rdump,
41 						unsigned long nr_rdump)
42 {
43 	struct samsung_clk_reg_dump *rd;
44 	unsigned int i;
45 
46 	rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL);
47 	if (!rd)
48 		return NULL;
49 
50 	for (i = 0; i < nr_rdump; ++i)
51 		rd[i].offset = rdump[i];
52 
53 	return rd;
54 }
55 
56 /**
57  * samsung_clk_init() - Create and initialize a clock provider object
58  * @dev:	CMU device to enable runtime PM, or NULL if RPM is not needed
59  * @base:	Start address (mapped) of CMU registers
60  * @nr_clks:	Total clock count to allocate in clock provider object
61  *
62  * Setup the essentials required to support clock lookup using Common Clock
63  * Framework.
64  *
65  * Return: Allocated and initialized clock provider object.
66  */
67 struct samsung_clk_provider * __init samsung_clk_init(struct device *dev,
68 			void __iomem *base, unsigned long nr_clks)
69 {
70 	struct samsung_clk_provider *ctx;
71 	int i;
72 
73 	ctx = kzalloc(struct_size(ctx, clk_data.hws, nr_clks), GFP_KERNEL);
74 	if (!ctx)
75 		panic("could not allocate clock provider context.\n");
76 
77 	for (i = 0; i < nr_clks; ++i)
78 		ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
79 
80 	ctx->dev = dev;
81 	ctx->reg_base = base;
82 	ctx->clk_data.num = nr_clks;
83 	spin_lock_init(&ctx->lock);
84 
85 	return ctx;
86 }
87 
88 void __init samsung_clk_of_add_provider(struct device_node *np,
89 				struct samsung_clk_provider *ctx)
90 {
91 	if (np) {
92 		if (of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
93 					&ctx->clk_data))
94 			panic("could not register clk provider\n");
95 	}
96 }
97 
98 /* add a clock instance to the clock lookup table used for dt based lookup */
99 void samsung_clk_add_lookup(struct samsung_clk_provider *ctx,
100 			    struct clk_hw *clk_hw, unsigned int id)
101 {
102 	if (id)
103 		ctx->clk_data.hws[id] = clk_hw;
104 }
105 
106 /* register a list of aliases */
107 void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx,
108 				const struct samsung_clock_alias *list,
109 				unsigned int nr_clk)
110 {
111 	struct clk_hw *clk_hw;
112 	unsigned int idx, ret;
113 
114 	for (idx = 0; idx < nr_clk; idx++, list++) {
115 		if (!list->id) {
116 			pr_err("%s: clock id missing for index %d\n", __func__,
117 				idx);
118 			continue;
119 		}
120 
121 		clk_hw = ctx->clk_data.hws[list->id];
122 		if (!clk_hw) {
123 			pr_err("%s: failed to find clock %d\n", __func__,
124 				list->id);
125 			continue;
126 		}
127 
128 		ret = clk_hw_register_clkdev(clk_hw, list->alias,
129 					     list->dev_name);
130 		if (ret)
131 			pr_err("%s: failed to register lookup %s\n",
132 					__func__, list->alias);
133 	}
134 }
135 
136 /* register a list of fixed clocks */
137 void __init samsung_clk_register_fixed_rate(struct samsung_clk_provider *ctx,
138 		const struct samsung_fixed_rate_clock *list,
139 		unsigned int nr_clk)
140 {
141 	struct clk_hw *clk_hw;
142 	unsigned int idx;
143 
144 	for (idx = 0; idx < nr_clk; idx++, list++) {
145 		clk_hw = clk_hw_register_fixed_rate(ctx->dev, list->name,
146 			list->parent_name, list->flags, list->fixed_rate);
147 		if (IS_ERR(clk_hw)) {
148 			pr_err("%s: failed to register clock %s\n", __func__,
149 				list->name);
150 			continue;
151 		}
152 
153 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
154 	}
155 }
156 
157 /* register a list of fixed factor clocks */
158 void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx,
159 		const struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
160 {
161 	struct clk_hw *clk_hw;
162 	unsigned int idx;
163 
164 	for (idx = 0; idx < nr_clk; idx++, list++) {
165 		clk_hw = clk_hw_register_fixed_factor(ctx->dev, list->name,
166 			list->parent_name, list->flags, list->mult, list->div);
167 		if (IS_ERR(clk_hw)) {
168 			pr_err("%s: failed to register clock %s\n", __func__,
169 				list->name);
170 			continue;
171 		}
172 
173 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
174 	}
175 }
176 
177 /* register a list of mux clocks */
178 void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx,
179 				const struct samsung_mux_clock *list,
180 				unsigned int nr_clk)
181 {
182 	struct clk_hw *clk_hw;
183 	unsigned int idx;
184 
185 	for (idx = 0; idx < nr_clk; idx++, list++) {
186 		clk_hw = clk_hw_register_mux(ctx->dev, list->name,
187 			list->parent_names, list->num_parents, list->flags,
188 			ctx->reg_base + list->offset,
189 			list->shift, list->width, list->mux_flags, &ctx->lock);
190 		if (IS_ERR(clk_hw)) {
191 			pr_err("%s: failed to register clock %s\n", __func__,
192 				list->name);
193 			continue;
194 		}
195 
196 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
197 	}
198 }
199 
200 /* register a list of div clocks */
201 void __init samsung_clk_register_div(struct samsung_clk_provider *ctx,
202 				const struct samsung_div_clock *list,
203 				unsigned int nr_clk)
204 {
205 	struct clk_hw *clk_hw;
206 	unsigned int idx;
207 
208 	for (idx = 0; idx < nr_clk; idx++, list++) {
209 		if (list->table)
210 			clk_hw = clk_hw_register_divider_table(ctx->dev,
211 				list->name, list->parent_name, list->flags,
212 				ctx->reg_base + list->offset,
213 				list->shift, list->width, list->div_flags,
214 				list->table, &ctx->lock);
215 		else
216 			clk_hw = clk_hw_register_divider(ctx->dev, list->name,
217 				list->parent_name, list->flags,
218 				ctx->reg_base + list->offset, list->shift,
219 				list->width, list->div_flags, &ctx->lock);
220 		if (IS_ERR(clk_hw)) {
221 			pr_err("%s: failed to register clock %s\n", __func__,
222 				list->name);
223 			continue;
224 		}
225 
226 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
227 	}
228 }
229 
230 /* register a list of gate clocks */
231 void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx,
232 				const struct samsung_gate_clock *list,
233 				unsigned int nr_clk)
234 {
235 	struct clk_hw *clk_hw;
236 	unsigned int idx;
237 
238 	for (idx = 0; idx < nr_clk; idx++, list++) {
239 		clk_hw = clk_hw_register_gate(ctx->dev, list->name, list->parent_name,
240 				list->flags, ctx->reg_base + list->offset,
241 				list->bit_idx, list->gate_flags, &ctx->lock);
242 		if (IS_ERR(clk_hw)) {
243 			pr_err("%s: failed to register clock %s\n", __func__,
244 				list->name);
245 			continue;
246 		}
247 
248 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
249 	}
250 }
251 
252 /*
253  * obtain the clock speed of all external fixed clock sources from device
254  * tree and register it
255  */
256 void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx,
257 			struct samsung_fixed_rate_clock *fixed_rate_clk,
258 			unsigned int nr_fixed_rate_clk,
259 			const struct of_device_id *clk_matches)
260 {
261 	const struct of_device_id *match;
262 	struct device_node *clk_np;
263 	u32 freq;
264 
265 	for_each_matching_node_and_match(clk_np, clk_matches, &match) {
266 		if (of_property_read_u32(clk_np, "clock-frequency", &freq))
267 			continue;
268 		fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq;
269 	}
270 	samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk);
271 }
272 
273 #ifdef CONFIG_PM_SLEEP
274 static int samsung_clk_suspend(void)
275 {
276 	struct samsung_clock_reg_cache *reg_cache;
277 
278 	list_for_each_entry(reg_cache, &clock_reg_cache_list, node) {
279 		samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
280 				reg_cache->rd_num);
281 		samsung_clk_restore(reg_cache->reg_base, reg_cache->rsuspend,
282 				reg_cache->rsuspend_num);
283 	}
284 	return 0;
285 }
286 
287 static void samsung_clk_resume(void)
288 {
289 	struct samsung_clock_reg_cache *reg_cache;
290 
291 	list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
292 		samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
293 				reg_cache->rd_num);
294 }
295 
296 static struct syscore_ops samsung_clk_syscore_ops = {
297 	.suspend = samsung_clk_suspend,
298 	.resume = samsung_clk_resume,
299 };
300 
301 void samsung_clk_extended_sleep_init(void __iomem *reg_base,
302 			const unsigned long *rdump,
303 			unsigned long nr_rdump,
304 			const struct samsung_clk_reg_dump *rsuspend,
305 			unsigned long nr_rsuspend)
306 {
307 	struct samsung_clock_reg_cache *reg_cache;
308 
309 	reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
310 			GFP_KERNEL);
311 	if (!reg_cache)
312 		panic("could not allocate register reg_cache.\n");
313 	reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);
314 
315 	if (!reg_cache->rdump)
316 		panic("could not allocate register dump storage.\n");
317 
318 	if (list_empty(&clock_reg_cache_list))
319 		register_syscore_ops(&samsung_clk_syscore_ops);
320 
321 	reg_cache->reg_base = reg_base;
322 	reg_cache->rd_num = nr_rdump;
323 	reg_cache->rsuspend = rsuspend;
324 	reg_cache->rsuspend_num = nr_rsuspend;
325 	list_add_tail(&reg_cache->node, &clock_reg_cache_list);
326 }
327 #endif
328 
329 /**
330  * samsung_cmu_register_clocks() - Register all clocks provided in CMU object
331  * @ctx: Clock provider object
332  * @cmu: CMU object with clocks to register
333  */
334 void __init samsung_cmu_register_clocks(struct samsung_clk_provider *ctx,
335 					const struct samsung_cmu_info *cmu)
336 {
337 	if (cmu->pll_clks)
338 		samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks);
339 	if (cmu->mux_clks)
340 		samsung_clk_register_mux(ctx, cmu->mux_clks, cmu->nr_mux_clks);
341 	if (cmu->div_clks)
342 		samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
343 	if (cmu->gate_clks)
344 		samsung_clk_register_gate(ctx, cmu->gate_clks,
345 					  cmu->nr_gate_clks);
346 	if (cmu->fixed_clks)
347 		samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
348 						cmu->nr_fixed_clks);
349 	if (cmu->fixed_factor_clks)
350 		samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
351 						  cmu->nr_fixed_factor_clks);
352 	if (cmu->cpu_clks)
353 		samsung_clk_register_cpu(ctx, cmu->cpu_clks, cmu->nr_cpu_clks);
354 }
355 
356 /*
357  * Common function which registers plls, muxes, dividers and gates
358  * for each CMU. It also add CMU register list to register cache.
359  */
360 struct samsung_clk_provider * __init samsung_cmu_register_one(
361 			struct device_node *np,
362 			const struct samsung_cmu_info *cmu)
363 {
364 	void __iomem *reg_base;
365 	struct samsung_clk_provider *ctx;
366 
367 	reg_base = of_iomap(np, 0);
368 	if (!reg_base) {
369 		panic("%s: failed to map registers\n", __func__);
370 		return NULL;
371 	}
372 
373 	ctx = samsung_clk_init(NULL, reg_base, cmu->nr_clk_ids);
374 	samsung_cmu_register_clocks(ctx, cmu);
375 
376 	if (cmu->clk_regs)
377 		samsung_clk_extended_sleep_init(reg_base,
378 			cmu->clk_regs, cmu->nr_clk_regs,
379 			cmu->suspend_regs, cmu->nr_suspend_regs);
380 
381 	samsung_clk_of_add_provider(np, ctx);
382 
383 	return ctx;
384 }
385