summaryrefslogtreecommitdiff
path: root/drivers/clk/ti/apll.c
blob: 83b148f8037c386339408f6856286cc29527e8b5 (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
411
412
413
414
415
416
/*
 * OMAP APLL clock support
 *
 * Copyright (C) 2013 Texas Instruments, Inc.
 *
 * J Keerthy <j-keerthy@ti.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/log2.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/clk/ti.h>
#include <linux/delay.h>

#include "clock.h"

#define APLL_FORCE_LOCK 0x1
#define APLL_AUTO_IDLE	0x2
#define MAX_APLL_WAIT_TRIES		1000000

#undef pr_fmt
#define pr_fmt(fmt) "%s: " fmt, __func__

static int dra7_apll_enable(struct clk_hw *hw)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
	int r = 0, i = 0;
	struct dpll_data *ad;
	const char *clk_name;
	u8 state = 1;
	u32 v;

	ad = clk->dpll_data;
	if (!ad)
		return -EINVAL;

	clk_name = clk_hw_get_name(&clk->hw);

	state <<= __ffs(ad->idlest_mask);

	/* Check is already locked */
	v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);

	if ((v & ad->idlest_mask) == state)
		return r;

	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
	v &= ~ad->enable_mask;
	v |= APLL_FORCE_LOCK << __ffs(ad->enable_mask);
	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);

	state <<= __ffs(ad->idlest_mask);

	while (1) {
		v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
		if ((v & ad->idlest_mask) == state)
			break;
		if (i > MAX_APLL_WAIT_TRIES)
			break;
		i++;
		udelay(1);
	}

	if (i == MAX_APLL_WAIT_TRIES) {
		pr_warn("clock: %s failed transition to '%s'\n",
			clk_name, (state) ? "locked" : "bypassed");
		r = -EBUSY;
	} else
		pr_debug("clock: %s transition to '%s' in %d loops\n",
			 clk_name, (state) ? "locked" : "bypassed", i);

	return r;
}

static void dra7_apll_disable(struct clk_hw *hw)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
	struct dpll_data *ad;
	u8 state = 1;
	u32 v;

	ad = clk->dpll_data;

	state <<= __ffs(ad->idlest_mask);

	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
	v &= ~ad->enable_mask;
	v |= APLL_AUTO_IDLE << __ffs(ad->enable_mask);
	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
}

static int dra7_apll_is_enabled(struct clk_hw *hw)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
	struct dpll_data *ad;
	u32 v;

	ad = clk->dpll_data;

	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
	v &= ad->enable_mask;

	v >>= __ffs(ad->enable_mask);

	return v == APLL_AUTO_IDLE ? 0 : 1;
}

static u8 dra7_init_apll_parent(struct clk_hw *hw)
{
	return 0;
}

static const struct clk_ops apll_ck_ops = {
	.enable		= &dra7_apll_enable,
	.disable	= &dra7_apll_disable,
	.is_enabled	= &dra7_apll_is_enabled,
	.get_parent	= &dra7_init_apll_parent,
};

static void __init omap_clk_register_apll(struct clk_hw *hw,
					  struct device_node *node)
{
	struct clk_hw_omap *clk_hw = to_clk_hw_omap(hw);
	struct dpll_data *ad = clk_hw->dpll_data;
	struct clk *clk;

	clk = of_clk_get(node, 0);
	if (IS_ERR(clk)) {
		pr_debug("clk-ref for %s not ready, retry\n",
			 node->name);
		if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
			return;

		goto cleanup;
	}

	ad->clk_ref = __clk_get_hw(clk);

	clk = of_clk_get(node, 1);
	if (IS_ERR(clk)) {
		pr_debug("clk-bypass for %s not ready, retry\n",
			 node->name);
		if (!ti_clk_retry_init(node, hw, omap_clk_register_apll))
			return;

		goto cleanup;
	}

	ad->clk_bypass = __clk_get_hw(clk);

	clk = ti_clk_register(NULL, &clk_hw->hw, node->name);
	if (!IS_ERR(clk)) {
		of_clk_add_provider(node, of_clk_src_simple_get, clk);
		kfree(clk_hw->hw.init->parent_names);
		kfree(clk_hw->hw.init);
		return;
	}

cleanup:
	kfree(clk_hw->dpll_data);
	kfree(clk_hw->hw.init->parent_names);
	kfree(clk_hw->hw.init);
	kfree(clk_hw);
}

static void __init of_dra7_apll_setup(struct device_node *node)
{
	struct dpll_data *ad = NULL;
	struct clk_hw_omap *clk_hw = NULL;
	struct clk_init_data *init = NULL;
	const char **parent_names = NULL;
	int ret;

	ad = kzalloc(sizeof(*ad), GFP_KERNEL);
	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
	init = kzalloc(sizeof(*init), GFP_KERNEL);
	if (!ad || !clk_hw || !init)
		goto cleanup;

	clk_hw->dpll_data = ad;
	clk_hw->hw.init = init;

	init->name = node->name;
	init->ops = &apll_ck_ops;

	init->num_parents = of_clk_get_parent_count(node);
	if (init->num_parents < 1) {
		pr_err("dra7 apll %s must have parent(s)\n", node->name);
		goto cleanup;
	}

	parent_names = kzalloc(sizeof(char *) * init->num_parents, GFP_KERNEL);
	if (!parent_names)
		goto cleanup;

	of_clk_parent_fill(node, parent_names, init->num_parents);

	init->parent_names = parent_names;

	ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg);
	ret |= ti_clk_get_reg_addr(node, 1, &ad->idlest_reg);

	if (ret)
		goto cleanup;

	ad->idlest_mask = 0x1;
	ad->enable_mask = 0x3;

	omap_clk_register_apll(&clk_hw->hw, node);
	return;

cleanup:
	kfree(parent_names);
	kfree(ad);
	kfree(clk_hw);
	kfree(init);
}
CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup);

#define OMAP2_EN_APLL_LOCKED	0x3
#define OMAP2_EN_APLL_STOPPED	0x0

static int omap2_apll_is_enabled(struct clk_hw *hw)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
	struct dpll_data *ad = clk->dpll_data;
	u32 v;

	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
	v &= ad->enable_mask;

	v >>= __ffs(ad->enable_mask);

	return v == OMAP2_EN_APLL_LOCKED ? 1 : 0;
}

static unsigned long omap2_apll_recalc(struct clk_hw *hw,
				       unsigned long parent_rate)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);

	if (omap2_apll_is_enabled(hw))
		return clk->fixed_rate;

	return 0;
}

static int omap2_apll_enable(struct clk_hw *hw)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
	struct dpll_data *ad = clk->dpll_data;
	u32 v;
	int i = 0;

	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
	v &= ~ad->enable_mask;
	v |= OMAP2_EN_APLL_LOCKED << __ffs(ad->enable_mask);
	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);

	while (1) {
		v = ti_clk_ll_ops->clk_readl(&ad->idlest_reg);
		if (v & ad->idlest_mask)
			break;
		if (i > MAX_APLL_WAIT_TRIES)
			break;
		i++;
		udelay(1);
	}

	if (i == MAX_APLL_WAIT_TRIES) {
		pr_warn("%s failed to transition to locked\n",
			clk_hw_get_name(&clk->hw));
		return -EBUSY;
	}

	return 0;
}

static void omap2_apll_disable(struct clk_hw *hw)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
	struct dpll_data *ad = clk->dpll_data;
	u32 v;

	v = ti_clk_ll_ops->clk_readl(&ad->control_reg);
	v &= ~ad->enable_mask;
	v |= OMAP2_EN_APLL_STOPPED << __ffs(ad->enable_mask);
	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
}

static const struct clk_ops omap2_apll_ops = {
	.enable		= &omap2_apll_enable,
	.disable	= &omap2_apll_disable,
	.is_enabled	= &omap2_apll_is_enabled,
	.recalc_rate	= &omap2_apll_recalc,
};

static void omap2_apll_set_autoidle(struct clk_hw_omap *clk, u32 val)
{
	struct dpll_data *ad = clk->dpll_data;
	u32 v;

	v = ti_clk_ll_ops->clk_readl(&ad->autoidle_reg);
	v &= ~ad->autoidle_mask;
	v |= val << __ffs(ad->autoidle_mask);
	ti_clk_ll_ops->clk_writel(v, &ad->control_reg);
}

#define OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP	0x3
#define OMAP2_APLL_AUTOIDLE_DISABLE		0x0

static void omap2_apll_allow_idle(struct clk_hw_omap *clk)
{
	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP);
}

static void omap2_apll_deny_idle(struct clk_hw_omap *clk)
{
	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_DISABLE);
}

static const struct clk_hw_omap_ops omap2_apll_hwops = {
	.allow_idle	= &omap2_apll_allow_idle,
	.deny_idle	= &omap2_apll_deny_idle,
};

static void __init of_omap2_apll_setup(struct device_node *node)
{
	struct dpll_data *ad = NULL;
	struct clk_hw_omap *clk_hw = NULL;
	struct clk_init_data *init = NULL;
	struct clk *clk;
	const char *parent_name;
	u32 val;
	int ret;

	ad = kzalloc(sizeof(*ad), GFP_KERNEL);
	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
	init = kzalloc(sizeof(*init), GFP_KERNEL);

	if (!ad || !clk_hw || !init)
		goto cleanup;

	clk_hw->dpll_data = ad;
	clk_hw->hw.init = init;
	init->ops = &omap2_apll_ops;
	init->name = node->name;
	clk_hw->ops = &omap2_apll_hwops;

	init->num_parents = of_clk_get_parent_count(node);
	if (init->num_parents != 1) {
		pr_err("%s must have one parent\n", node->name);
		goto cleanup;
	}

	parent_name = of_clk_get_parent_name(node, 0);
	init->parent_names = &parent_name;

	if (of_property_read_u32(node, "ti,clock-frequency", &val)) {
		pr_err("%s missing clock-frequency\n", node->name);
		goto cleanup;
	}
	clk_hw->fixed_rate = val;

	if (of_property_read_u32(node, "ti,bit-shift", &val)) {
		pr_err("%s missing bit-shift\n", node->name);
		goto cleanup;
	}

	clk_hw->enable_bit = val;
	ad->enable_mask = 0x3 << val;
	ad->autoidle_mask = 0x3 << val;

	if (of_property_read_u32(node, "ti,idlest-shift", &val)) {
		pr_err("%s missing idlest-shift\n", node->name);
		goto cleanup;
	}

	ad->idlest_mask = 1 << val;

	ret = ti_clk_get_reg_addr(node, 0, &ad->control_reg);
	ret |= ti_clk_get_reg_addr(node, 1, &ad->autoidle_reg);
	ret |= ti_clk_get_reg_addr(node, 2, &ad->idlest_reg);

	if (ret)
		goto cleanup;

	clk = clk_register(NULL, &clk_hw->hw);
	if (!IS_ERR(clk)) {
		of_clk_add_provider(node, of_clk_src_simple_get, clk);
		kfree(init);
		return;
	}
cleanup:
	kfree(ad);
	kfree(clk_hw);
	kfree(init);
}
CLK_OF_DECLARE(omap2_apll_clock, "ti,omap2-apll-clock",
	       of_omap2_apll_setup);