aboutsummaryrefslogtreecommitdiff
path: root/drivers/clk/at91/clk-peripheral.c
blob: 597fed423d7d31906b1ca37f3fa9931231a63460 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
/*
 *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */

#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/io.h>

#include "pmc.h"

#define PERIPHERAL_MAX		64

#define PERIPHERAL_AT91RM9200	0
#define PERIPHERAL_AT91SAM9X5	1

#define PERIPHERAL_ID_MIN	2
#define PERIPHERAL_ID_MAX	31
#define PERIPHERAL_MASK(id)	(1 << ((id) & PERIPHERAL_ID_MAX))

#define PERIPHERAL_RSHIFT_MASK	0x3
#define PERIPHERAL_RSHIFT(val)	(((val) >> 16) & PERIPHERAL_RSHIFT_MASK)

#define PERIPHERAL_MAX_SHIFT	4

struct clk_peripheral {
	struct clk_hw hw;
	struct at91_pmc *pmc;
	u32 id;
};

#define to_clk_peripheral(hw) container_of(hw, struct clk_peripheral, hw)

struct clk_sam9x5_peripheral {
	struct clk_hw hw;
	struct at91_pmc *pmc;
	struct clk_range range;
	u32 id;
	u32 div;
	bool auto_div;
};

#define to_clk_sam9x5_peripheral(hw) \
	container_of(hw, struct clk_sam9x5_peripheral, hw)

static int clk_peripheral_enable(struct clk_hw *hw)
{
	struct clk_peripheral *periph = to_clk_peripheral(hw);
	struct at91_pmc *pmc = periph->pmc;
	int offset = AT91_PMC_PCER;
	u32 id = periph->id;

	if (id < PERIPHERAL_ID_MIN)
		return 0;
	if (id > PERIPHERAL_ID_MAX)
		offset = AT91_PMC_PCER1;
	pmc_write(pmc, offset, PERIPHERAL_MASK(id));
	return 0;
}

static void clk_peripheral_disable(struct clk_hw *hw)
{
	struct clk_peripheral *periph = to_clk_peripheral(hw);
	struct at91_pmc *pmc = periph->pmc;
	int offset = AT91_PMC_PCDR;
	u32 id = periph->id;

	if (id < PERIPHERAL_ID_MIN)
		return;
	if (id > PERIPHERAL_ID_MAX)
		offset = AT91_PMC_PCDR1;
	pmc_write(pmc, offset, PERIPHERAL_MASK(id));
}

static int clk_peripheral_is_enabled(struct clk_hw *hw)
{
	struct clk_peripheral *periph = to_clk_peripheral(hw);
	struct at91_pmc *pmc = periph->pmc;
	int offset = AT91_PMC_PCSR;
	u32 id = periph->id;

	if (id < PERIPHERAL_ID_MIN)
		return 1;
	if (id > PERIPHERAL_ID_MAX)
		offset = AT91_PMC_PCSR1;
	return !!(pmc_read(pmc, offset) & PERIPHERAL_MASK(id));
}

static const struct clk_ops peripheral_ops = {
	.enable = clk_peripheral_enable,
	.disable = clk_peripheral_disable,
	.is_enabled = clk_peripheral_is_enabled,
};

static struct clk * __init
at91_clk_register_peripheral(struct at91_pmc *pmc, const char *name,
			     const char *parent_name, u32 id)
{
	struct clk_peripheral *periph;
	struct clk *clk = NULL;
	struct clk_init_data init;

	if (!pmc || !name || !parent_name || id > PERIPHERAL_ID_MAX)
		return ERR_PTR(-EINVAL);

	periph = kzalloc(sizeof(*periph), GFP_KERNEL);
	if (!periph)
		return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &peripheral_ops;
	init.parent_names = (parent_name ? &parent_name : NULL);
	init.num_parents = (parent_name ? 1 : 0);
	init.flags = 0;

	periph->id = id;
	periph->hw.init = &init;
	periph->pmc = pmc;

	clk = clk_register(NULL, &periph->hw);
	if (IS_ERR(clk))
		kfree(periph);

	return clk;
}

static void clk_sam9x5_peripheral_autodiv(struct clk_sam9x5_peripheral *periph)
{
	struct clk *parent;
	unsigned long parent_rate;
	int shift = 0;

	if (!periph->auto_div)
		return;

	if (periph->range.max) {
		parent = clk_get_parent_by_index(periph->hw.clk, 0);
		parent_rate = __clk_get_rate(parent);
		if (!parent_rate)
			return;

		for (; shift < PERIPHERAL_MAX_SHIFT; shift++) {
			if (parent_rate >> shift <= periph->range.max)
				break;
		}
	}

	periph->auto_div = false;
	periph->div = shift;
}

static int clk_sam9x5_peripheral_enable(struct clk_hw *hw)
{
	struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
	struct at91_pmc *pmc = periph->pmc;

	if (periph->id < PERIPHERAL_ID_MIN)
		return 0;

	pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID) |
				     AT91_PMC_PCR_CMD |
				     AT91_PMC_PCR_DIV(periph->div) |
				     AT91_PMC_PCR_EN);
	return 0;
}

static void clk_sam9x5_peripheral_disable(struct clk_hw *hw)
{
	struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
	struct at91_pmc *pmc = periph->pmc;

	if (periph->id < PERIPHERAL_ID_MIN)
		return;

	pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID) |
				     AT91_PMC_PCR_CMD);
}

static int clk_sam9x5_peripheral_is_enabled(struct clk_hw *hw)
{
	struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
	struct at91_pmc *pmc = periph->pmc;
	int ret;

	if (periph->id < PERIPHERAL_ID_MIN)
		return 1;

	pmc_lock(pmc);
	pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID));
	ret = !!(pmc_read(pmc, AT91_PMC_PCR) & AT91_PMC_PCR_EN);
	pmc_unlock(pmc);

	return ret;
}

static unsigned long
clk_sam9x5_peripheral_recalc_rate(struct clk_hw *hw,
				  unsigned long parent_rate)
{
	struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
	struct at91_pmc *pmc = periph->pmc;
	u32 tmp;

	if (periph->id < PERIPHERAL_ID_MIN)
		return parent_rate;

	pmc_lock(pmc);
	pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID));
	tmp = pmc_read(pmc, AT91_PMC_PCR);
	pmc_unlock(pmc);

	if (tmp & AT91_PMC_PCR_EN) {
		periph->div = PERIPHERAL_RSHIFT(tmp);
		periph->auto_div = false;
	} else {
		clk_sam9x5_peripheral_autodiv(periph);
	}

	return parent_rate >> periph->div;
}

static long clk_sam9x5_peripheral_round_rate(struct clk_hw *hw,
					     unsigned long rate,
					     unsigned long *parent_rate)
{
	int shift = 0;
	unsigned long best_rate;
	unsigned long best_diff;
	unsigned long cur_rate = *parent_rate;
	unsigned long cur_diff;
	struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);

	if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max)
		return *parent_rate;

	if (periph->range.max) {
		for (; shift < PERIPHERAL_MAX_SHIFT; shift++) {
			cur_rate = *parent_rate >> shift;
			if (cur_rate <= periph->range.max)
				break;
		}
	}

	if (rate >= cur_rate)
		return cur_rate;

	best_diff = cur_rate - rate;
	best_rate = cur_rate;
	for (; shift < PERIPHERAL_MAX_SHIFT; shift++) {
		cur_rate = *parent_rate >> shift;
		if (cur_rate < rate)
			cur_diff = rate - cur_rate;
		else
			cur_diff = cur_rate - rate;

		if (cur_diff < best_diff) {
			best_diff = cur_diff;
			best_rate = cur_rate;
		}

		if (!best_diff || cur_rate < rate)
			break;
	}

	return best_rate;
}

static int clk_sam9x5_peripheral_set_rate(struct clk_hw *hw,
					  unsigned long rate,
					  unsigned long parent_rate)
{
	int shift;
	struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
	if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max) {
		if (parent_rate == rate)
			return 0;
		else
			return -EINVAL;
	}

	if (periph->range.max && rate > periph->range.max)
		return -EINVAL;

	for (shift = 0; shift < PERIPHERAL_MAX_SHIFT; shift++) {
		if (parent_rate >> shift == rate) {
			periph->auto_div = false;
			periph->div = shift;
			return 0;
		}
	}

	return -EINVAL;
}

static const struct clk_ops sam9x5_peripheral_ops = {
	.enable = clk_sam9x5_peripheral_enable,
	.disable = clk_sam9x5_peripheral_disable,
	.is_enabled = clk_sam9x5_peripheral_is_enabled,
	.recalc_rate = clk_sam9x5_peripheral_recalc_rate,
	.round_rate = clk_sam9x5_peripheral_round_rate,
	.set_rate = clk_sam9x5_peripheral_set_rate,
};

static struct clk * __init
at91_clk_register_sam9x5_peripheral(struct at91_pmc *pmc, const char *name,
				    const char *parent_name, u32 id,
				    const struct clk_range *range)
{
	struct clk_sam9x5_peripheral *periph;
	struct clk *clk = NULL;
	struct clk_init_data init;

	if (!pmc || !name || !parent_name)
		return ERR_PTR(-EINVAL);

	periph = kzalloc(sizeof(*periph), GFP_KERNEL);
	if (!periph)
		return ERR_PTR(-ENOMEM);

	init.name = name;
	init.ops = &sam9x5_peripheral_ops;
	init.parent_names = (parent_name ? &parent_name : NULL);
	init.num_parents = (parent_name ? 1 : 0);
	init.flags = 0;

	periph->id = id;
	periph->hw.init = &init;
	periph->div = 0;
	periph->pmc = pmc;
	periph->auto_div = true;
	periph->range = *range;

	clk = clk_register(NULL, &periph->hw);
	if (IS_ERR(clk))
		kfree(periph);
	else
		clk_sam9x5_peripheral_autodiv(periph);

	return clk;
}

static void __init
of_at91_clk_periph_setup(struct device_node *np, struct at91_pmc *pmc, u8 type)
{
	int num;
	u32 id;
	struct clk *clk;
	const char *parent_name;
	const char *name;
	struct device_node *periphclknp;

	parent_name = of_clk_get_parent_name(np, 0);
	if (!parent_name)
		return;

	num = of_get_child_count(np);
	if (!num || num > PERIPHERAL_MAX)
		return;

	for_each_child_of_node(np, periphclknp) {
		if (of_property_read_u32(periphclknp, "reg", &id))
			continue;

		if (id >= PERIPHERAL_MAX)
			continue;

		if (of_property_read_string(np, "clock-output-names", &name))
			name = periphclknp->name;

		if (type == PERIPHERAL_AT91RM9200) {
			clk = at91_clk_register_peripheral(pmc, name,
							   parent_name, id);
		} else {
			struct clk_range range = CLK_RANGE(0, 0);

			of_at91_get_clk_range(periphclknp,
					      "atmel,clk-output-range",
					      &range);

			clk = at91_clk_register_sam9x5_peripheral(pmc, name,
								  parent_name,
								  id, &range);
		}

		if (IS_ERR(clk))
			continue;

		of_clk_add_provider(periphclknp, of_clk_src_simple_get, clk);
	}
}

void __init of_at91rm9200_clk_periph_setup(struct device_node *np,
					   struct at91_pmc *pmc)
{
	of_at91_clk_periph_setup(np, pmc, PERIPHERAL_AT91RM9200);
}

void __init of_at91sam9x5_clk_periph_setup(struct device_node *np,
					   struct at91_pmc *pmc)
{
	of_at91_clk_periph_setup(np, pmc, PERIPHERAL_AT91SAM9X5);
}