xref: /openbmc/linux/drivers/clk/samsung/clk.c (revision 15e3ae36) 
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 /* setup the essentials required to support clock lookup using ccf */
57 struct samsung_clk_provider *__init samsung_clk_init(struct device_node *np,
58 			void __iomem *base, unsigned long nr_clks)
59 {
60 	struct samsung_clk_provider *ctx;
61 	int i;
62 
63 	ctx = kzalloc(struct_size(ctx, clk_data.hws, nr_clks), GFP_KERNEL);
64 	if (!ctx)
65 		panic("could not allocate clock provider context.\n");
66 
67 	for (i = 0; i < nr_clks; ++i)
68 		ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
69 
70 	ctx->reg_base = base;
71 	ctx->clk_data.num = nr_clks;
72 	spin_lock_init(&ctx->lock);
73 
74 	return ctx;
75 }
76 
77 void __init samsung_clk_of_add_provider(struct device_node *np,
78 				struct samsung_clk_provider *ctx)
79 {
80 	if (np) {
81 		if (of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
82 					&ctx->clk_data))
83 			panic("could not register clk provider\n");
84 	}
85 }
86 
87 /* add a clock instance to the clock lookup table used for dt based lookup */
88 void samsung_clk_add_lookup(struct samsung_clk_provider *ctx,
89 			    struct clk_hw *clk_hw, unsigned int id)
90 {
91 	if (id)
92 		ctx->clk_data.hws[id] = clk_hw;
93 }
94 
95 /* register a list of aliases */
96 void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx,
97 				const struct samsung_clock_alias *list,
98 				unsigned int nr_clk)
99 {
100 	struct clk_hw *clk_hw;
101 	unsigned int idx, ret;
102 
103 	for (idx = 0; idx < nr_clk; idx++, list++) {
104 		if (!list->id) {
105 			pr_err("%s: clock id missing for index %d\n", __func__,
106 				idx);
107 			continue;
108 		}
109 
110 		clk_hw = ctx->clk_data.hws[list->id];
111 		if (!clk_hw) {
112 			pr_err("%s: failed to find clock %d\n", __func__,
113 				list->id);
114 			continue;
115 		}
116 
117 		ret = clk_hw_register_clkdev(clk_hw, list->alias,
118 					     list->dev_name);
119 		if (ret)
120 			pr_err("%s: failed to register lookup %s\n",
121 					__func__, list->alias);
122 	}
123 }
124 
125 /* register a list of fixed clocks */
126 void __init samsung_clk_register_fixed_rate(struct samsung_clk_provider *ctx,
127 		const struct samsung_fixed_rate_clock *list,
128 		unsigned int nr_clk)
129 {
130 	struct clk_hw *clk_hw;
131 	unsigned int idx, ret;
132 
133 	for (idx = 0; idx < nr_clk; idx++, list++) {
134 		clk_hw = clk_hw_register_fixed_rate(ctx->dev, list->name,
135 			list->parent_name, list->flags, list->fixed_rate);
136 		if (IS_ERR(clk_hw)) {
137 			pr_err("%s: failed to register clock %s\n", __func__,
138 				list->name);
139 			continue;
140 		}
141 
142 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
143 
144 		/*
145 		 * Unconditionally add a clock lookup for the fixed rate clocks.
146 		 * There are not many of these on any of Samsung platforms.
147 		 */
148 		ret = clk_hw_register_clkdev(clk_hw, list->name, NULL);
149 		if (ret)
150 			pr_err("%s: failed to register clock lookup for %s",
151 				__func__, list->name);
152 	}
153 }
154 
155 /* register a list of fixed factor clocks */
156 void __init samsung_clk_register_fixed_factor(struct samsung_clk_provider *ctx,
157 		const struct samsung_fixed_factor_clock *list, unsigned int nr_clk)
158 {
159 	struct clk_hw *clk_hw;
160 	unsigned int idx;
161 
162 	for (idx = 0; idx < nr_clk; idx++, list++) {
163 		clk_hw = clk_hw_register_fixed_factor(ctx->dev, list->name,
164 			list->parent_name, list->flags, list->mult, list->div);
165 		if (IS_ERR(clk_hw)) {
166 			pr_err("%s: failed to register clock %s\n", __func__,
167 				list->name);
168 			continue;
169 		}
170 
171 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
172 	}
173 }
174 
175 /* register a list of mux clocks */
176 void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx,
177 				const struct samsung_mux_clock *list,
178 				unsigned int nr_clk)
179 {
180 	struct clk_hw *clk_hw;
181 	unsigned int idx;
182 
183 	for (idx = 0; idx < nr_clk; idx++, list++) {
184 		clk_hw = clk_hw_register_mux(ctx->dev, list->name,
185 			list->parent_names, list->num_parents, list->flags,
186 			ctx->reg_base + list->offset,
187 			list->shift, list->width, list->mux_flags, &ctx->lock);
188 		if (IS_ERR(clk_hw)) {
189 			pr_err("%s: failed to register clock %s\n", __func__,
190 				list->name);
191 			continue;
192 		}
193 
194 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
195 	}
196 }
197 
198 /* register a list of div clocks */
199 void __init samsung_clk_register_div(struct samsung_clk_provider *ctx,
200 				const struct samsung_div_clock *list,
201 				unsigned int nr_clk)
202 {
203 	struct clk_hw *clk_hw;
204 	unsigned int idx;
205 
206 	for (idx = 0; idx < nr_clk; idx++, list++) {
207 		if (list->table)
208 			clk_hw = clk_hw_register_divider_table(ctx->dev,
209 				list->name, list->parent_name, list->flags,
210 				ctx->reg_base + list->offset,
211 				list->shift, list->width, list->div_flags,
212 				list->table, &ctx->lock);
213 		else
214 			clk_hw = clk_hw_register_divider(ctx->dev, list->name,
215 				list->parent_name, list->flags,
216 				ctx->reg_base + list->offset, list->shift,
217 				list->width, list->div_flags, &ctx->lock);
218 		if (IS_ERR(clk_hw)) {
219 			pr_err("%s: failed to register clock %s\n", __func__,
220 				list->name);
221 			continue;
222 		}
223 
224 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
225 	}
226 }
227 
228 /* register a list of gate clocks */
229 void __init samsung_clk_register_gate(struct samsung_clk_provider *ctx,
230 				const struct samsung_gate_clock *list,
231 				unsigned int nr_clk)
232 {
233 	struct clk_hw *clk_hw;
234 	unsigned int idx;
235 
236 	for (idx = 0; idx < nr_clk; idx++, list++) {
237 		clk_hw = clk_hw_register_gate(ctx->dev, list->name, list->parent_name,
238 				list->flags, ctx->reg_base + list->offset,
239 				list->bit_idx, list->gate_flags, &ctx->lock);
240 		if (IS_ERR(clk_hw)) {
241 			pr_err("%s: failed to register clock %s\n", __func__,
242 				list->name);
243 			continue;
244 		}
245 
246 		samsung_clk_add_lookup(ctx, clk_hw, list->id);
247 	}
248 }
249 
250 /*
251  * obtain the clock speed of all external fixed clock sources from device
252  * tree and register it
253  */
254 void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx,
255 			struct samsung_fixed_rate_clock *fixed_rate_clk,
256 			unsigned int nr_fixed_rate_clk,
257 			const struct of_device_id *clk_matches)
258 {
259 	const struct of_device_id *match;
260 	struct device_node *clk_np;
261 	u32 freq;
262 
263 	for_each_matching_node_and_match(clk_np, clk_matches, &match) {
264 		if (of_property_read_u32(clk_np, "clock-frequency", &freq))
265 			continue;
266 		fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq;
267 	}
268 	samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk);
269 }
270 
271 /* utility function to get the rate of a specified clock */
272 unsigned long _get_rate(const char *clk_name)
273 {
274 	struct clk *clk;
275 
276 	clk = __clk_lookup(clk_name);
277 	if (!clk) {
278 		pr_err("%s: could not find clock %s\n", __func__, clk_name);
279 		return 0;
280 	}
281 
282 	return clk_get_rate(clk);
283 }
284 
285 #ifdef CONFIG_PM_SLEEP
286 static int samsung_clk_suspend(void)
287 {
288 	struct samsung_clock_reg_cache *reg_cache;
289 
290 	list_for_each_entry(reg_cache, &clock_reg_cache_list, node) {
291 		samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
292 				reg_cache->rd_num);
293 		samsung_clk_restore(reg_cache->reg_base, reg_cache->rsuspend,
294 				reg_cache->rsuspend_num);
295 	}
296 	return 0;
297 }
298 
299 static void samsung_clk_resume(void)
300 {
301 	struct samsung_clock_reg_cache *reg_cache;
302 
303 	list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
304 		samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
305 				reg_cache->rd_num);
306 }
307 
308 static struct syscore_ops samsung_clk_syscore_ops = {
309 	.suspend = samsung_clk_suspend,
310 	.resume = samsung_clk_resume,
311 };
312 
313 void samsung_clk_extended_sleep_init(void __iomem *reg_base,
314 			const unsigned long *rdump,
315 			unsigned long nr_rdump,
316 			const struct samsung_clk_reg_dump *rsuspend,
317 			unsigned long nr_rsuspend)
318 {
319 	struct samsung_clock_reg_cache *reg_cache;
320 
321 	reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
322 			GFP_KERNEL);
323 	if (!reg_cache)
324 		panic("could not allocate register reg_cache.\n");
325 	reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);
326 
327 	if (!reg_cache->rdump)
328 		panic("could not allocate register dump storage.\n");
329 
330 	if (list_empty(&clock_reg_cache_list))
331 		register_syscore_ops(&samsung_clk_syscore_ops);
332 
333 	reg_cache->reg_base = reg_base;
334 	reg_cache->rd_num = nr_rdump;
335 	reg_cache->rsuspend = rsuspend;
336 	reg_cache->rsuspend_num = nr_rsuspend;
337 	list_add_tail(&reg_cache->node, &clock_reg_cache_list);
338 }
339 #endif
340 
341 /*
342  * Common function which registers plls, muxes, dividers and gates
343  * for each CMU. It also add CMU register list to register cache.
344  */
345 struct samsung_clk_provider * __init samsung_cmu_register_one(
346 			struct device_node *np,
347 			const struct samsung_cmu_info *cmu)
348 {
349 	void __iomem *reg_base;
350 	struct samsung_clk_provider *ctx;
351 
352 	reg_base = of_iomap(np, 0);
353 	if (!reg_base) {
354 		panic("%s: failed to map registers\n", __func__);
355 		return NULL;
356 	}
357 
358 	ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids);
359 
360 	if (cmu->pll_clks)
361 		samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks,
362 			reg_base);
363 	if (cmu->mux_clks)
364 		samsung_clk_register_mux(ctx, cmu->mux_clks,
365 			cmu->nr_mux_clks);
366 	if (cmu->div_clks)
367 		samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
368 	if (cmu->gate_clks)
369 		samsung_clk_register_gate(ctx, cmu->gate_clks,
370 			cmu->nr_gate_clks);
371 	if (cmu->fixed_clks)
372 		samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
373 			cmu->nr_fixed_clks);
374 	if (cmu->fixed_factor_clks)
375 		samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
376 			cmu->nr_fixed_factor_clks);
377 	if (cmu->clk_regs)
378 		samsung_clk_extended_sleep_init(reg_base,
379 			cmu->clk_regs, cmu->nr_clk_regs,
380 			cmu->suspend_regs, cmu->nr_suspend_regs);
381 
382 	samsung_clk_of_add_provider(np, ctx);
383 
384 	return ctx;
385 }
386