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  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
 21static LIST_HEAD(clock_reg_cache_list);
 22
 23void 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
 31void 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
 39struct 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 */
 57struct 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
 77void __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 */
 88void 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 */
 96void __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 */
126void __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 */
156void __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 */
176void __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 */
199void __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 */
229void __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 */
254void __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#ifdef CONFIG_PM_SLEEP
272static int samsung_clk_suspend(void)
273{
274	struct samsung_clock_reg_cache *reg_cache;
275
276	list_for_each_entry(reg_cache, &clock_reg_cache_list, node) {
277		samsung_clk_save(reg_cache->reg_base, reg_cache->rdump,
278				reg_cache->rd_num);
279		samsung_clk_restore(reg_cache->reg_base, reg_cache->rsuspend,
280				reg_cache->rsuspend_num);
281	}
282	return 0;
283}
284
285static void samsung_clk_resume(void)
286{
287	struct samsung_clock_reg_cache *reg_cache;
288
289	list_for_each_entry(reg_cache, &clock_reg_cache_list, node)
290		samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump,
291				reg_cache->rd_num);
292}
293
294static struct syscore_ops samsung_clk_syscore_ops = {
295	.suspend = samsung_clk_suspend,
296	.resume = samsung_clk_resume,
297};
298
299void samsung_clk_extended_sleep_init(void __iomem *reg_base,
300			const unsigned long *rdump,
301			unsigned long nr_rdump,
302			const struct samsung_clk_reg_dump *rsuspend,
303			unsigned long nr_rsuspend)
304{
305	struct samsung_clock_reg_cache *reg_cache;
306
307	reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache),
308			GFP_KERNEL);
309	if (!reg_cache)
310		panic("could not allocate register reg_cache.\n");
311	reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump);
312
313	if (!reg_cache->rdump)
314		panic("could not allocate register dump storage.\n");
315
316	if (list_empty(&clock_reg_cache_list))
317		register_syscore_ops(&samsung_clk_syscore_ops);
318
319	reg_cache->reg_base = reg_base;
320	reg_cache->rd_num = nr_rdump;
321	reg_cache->rsuspend = rsuspend;
322	reg_cache->rsuspend_num = nr_rsuspend;
323	list_add_tail(&reg_cache->node, &clock_reg_cache_list);
324}
325#endif
326
327/*
328 * Common function which registers plls, muxes, dividers and gates
329 * for each CMU. It also add CMU register list to register cache.
330 */
331struct samsung_clk_provider * __init samsung_cmu_register_one(
332			struct device_node *np,
333			const struct samsung_cmu_info *cmu)
334{
335	void __iomem *reg_base;
336	struct samsung_clk_provider *ctx;
337
338	reg_base = of_iomap(np, 0);
339	if (!reg_base) {
340		panic("%s: failed to map registers\n", __func__);
341		return NULL;
342	}
343
344	ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids);
345
346	if (cmu->pll_clks)
347		samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks,
348			reg_base);
349	if (cmu->mux_clks)
350		samsung_clk_register_mux(ctx, cmu->mux_clks,
351			cmu->nr_mux_clks);
352	if (cmu->div_clks)
353		samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks);
354	if (cmu->gate_clks)
355		samsung_clk_register_gate(ctx, cmu->gate_clks,
356			cmu->nr_gate_clks);
357	if (cmu->fixed_clks)
358		samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks,
359			cmu->nr_fixed_clks);
360	if (cmu->fixed_factor_clks)
361		samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks,
362			cmu->nr_fixed_factor_clks);
363	if (cmu->clk_regs)
364		samsung_clk_extended_sleep_init(reg_base,
365			cmu->clk_regs, cmu->nr_clk_regs,
366			cmu->suspend_regs, cmu->nr_suspend_regs);
367	if (cmu->cpu_clks)
368		samsung_clk_register_cpu(ctx, cmu->cpu_clks, cmu->nr_cpu_clks);
369
370	samsung_clk_of_add_provider(np, ctx);
371
372	return ctx;
373}