aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/clk/clk-wm831x.c
blob: ae6dd38ec0537c7234718d5bfb22eea40855d738 (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * WM831x clock control
 *
 * Copyright 2011-2 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 */

#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/mfd/wm831x/core.h>

struct wm831x_clk {
	struct wm831x *wm831x;
	struct clk_hw xtal_hw;
	struct clk_hw fll_hw;
	struct clk_hw clkout_hw;
	bool xtal_ena;
};

static int wm831x_xtal_is_prepared(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  xtal_hw);

	return clkdata->xtal_ena;
}

static unsigned long wm831x_xtal_recalc_rate(struct clk_hw *hw,
					     unsigned long parent_rate)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  xtal_hw);

	if (clkdata->xtal_ena)
		return 32768;
	else
		return 0;
}

static const struct clk_ops wm831x_xtal_ops = {
	.is_prepared = wm831x_xtal_is_prepared,
	.recalc_rate = wm831x_xtal_recalc_rate,
};

static const struct clk_init_data wm831x_xtal_init = {
	.name = "xtal",
	.ops = &wm831x_xtal_ops,
};

static const unsigned long wm831x_fll_auto_rates[] = {
	 2048000,
	11289600,
	12000000,
	12288000,
	19200000,
	22579600,
	24000000,
	24576000,
};

static int wm831x_fll_is_prepared(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_1);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read FLL_CONTROL_1: %d\n",
			ret);
		return true;
	}

	return (ret & WM831X_FLL_ENA) != 0;
}

static int wm831x_fll_prepare(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1,
			      WM831X_FLL_ENA, WM831X_FLL_ENA);
	if (ret != 0)
		dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret);

	/* wait 2-3 ms for new frequency taking effect */
	usleep_range(2000, 3000);

	return ret;
}

static void wm831x_fll_unprepare(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1, WM831X_FLL_ENA, 0);
	if (ret != 0)
		dev_crit(wm831x->dev, "Failed to disable FLL: %d\n", ret);
}

static unsigned long wm831x_fll_recalc_rate(struct clk_hw *hw,
					    unsigned long parent_rate)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
			ret);
		return 0;
	}

	if (ret & WM831X_FLL_AUTO)
		return wm831x_fll_auto_rates[ret & WM831X_FLL_AUTO_FREQ_MASK];

	dev_err(wm831x->dev, "FLL only supported in AUTO mode\n");

	return 0;
}

static long wm831x_fll_round_rate(struct clk_hw *hw, unsigned long rate,
				  unsigned long *unused)
{
	int best = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
		if (abs(wm831x_fll_auto_rates[i] - rate) <
		    abs(wm831x_fll_auto_rates[best] - rate))
			best = i;

	return wm831x_fll_auto_rates[best];
}

static int wm831x_fll_set_rate(struct clk_hw *hw, unsigned long rate,
			       unsigned long parent_rate)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int i;

	for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
		if (wm831x_fll_auto_rates[i] == rate)
			break;
	if (i == ARRAY_SIZE(wm831x_fll_auto_rates))
		return -EINVAL;

	if (wm831x_fll_is_prepared(hw))
		return -EPERM;

	return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_2,
			       WM831X_FLL_AUTO_FREQ_MASK, i);
}

static const char *wm831x_fll_parents[] = {
	"xtal",
	"clkin",
};

static u8 wm831x_fll_get_parent(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	/* AUTO mode is always clocked from the crystal */
	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
			ret);
		return 0;
	}

	if (ret & WM831X_FLL_AUTO)
		return 0;

	ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_5);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read FLL_CONTROL_5: %d\n",
			ret);
		return 0;
	}

	switch (ret & WM831X_FLL_CLK_SRC_MASK) {
	case 0:
		return 0;
	case 1:
		return 1;
	default:
		dev_err(wm831x->dev, "Unsupported FLL clock source %d\n",
			ret & WM831X_FLL_CLK_SRC_MASK);
		return 0;
	}
}

static const struct clk_ops wm831x_fll_ops = {
	.is_prepared = wm831x_fll_is_prepared,
	.prepare = wm831x_fll_prepare,
	.unprepare = wm831x_fll_unprepare,
	.round_rate = wm831x_fll_round_rate,
	.recalc_rate = wm831x_fll_recalc_rate,
	.set_rate = wm831x_fll_set_rate,
	.get_parent = wm831x_fll_get_parent,
};

static const struct clk_init_data wm831x_fll_init = {
	.name = "fll",
	.ops = &wm831x_fll_ops,
	.parent_names = wm831x_fll_parents,
	.num_parents = ARRAY_SIZE(wm831x_fll_parents),
	.flags = CLK_SET_RATE_GATE,
};

static int wm831x_clkout_is_prepared(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
			ret);
		return false;
	}

	return (ret & WM831X_CLKOUT_ENA) != 0;
}

static int wm831x_clkout_prepare(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_unlock(wm831x);
	if (ret != 0) {
		dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
		return ret;
	}

	ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
			      WM831X_CLKOUT_ENA, WM831X_CLKOUT_ENA);
	if (ret != 0)
		dev_crit(wm831x->dev, "Failed to enable CLKOUT: %d\n", ret);

	wm831x_reg_lock(wm831x);

	return ret;
}

static void wm831x_clkout_unprepare(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_unlock(wm831x);
	if (ret != 0) {
		dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
		return;
	}

	ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
			      WM831X_CLKOUT_ENA, 0);
	if (ret != 0)
		dev_crit(wm831x->dev, "Failed to disable CLKOUT: %d\n", ret);

	wm831x_reg_lock(wm831x);
}

static const char *wm831x_clkout_parents[] = {
	"fll",
	"xtal",
};

static u8 wm831x_clkout_get_parent(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
			ret);
		return 0;
	}

	if (ret & WM831X_CLKOUT_SRC)
		return 1;
	else
		return 0;
}

static int wm831x_clkout_set_parent(struct clk_hw *hw, u8 parent)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;

	return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
			       WM831X_CLKOUT_SRC,
			       parent << WM831X_CLKOUT_SRC_SHIFT);
}

static const struct clk_ops wm831x_clkout_ops = {
	.is_prepared = wm831x_clkout_is_prepared,
	.prepare = wm831x_clkout_prepare,
	.unprepare = wm831x_clkout_unprepare,
	.get_parent = wm831x_clkout_get_parent,
	.set_parent = wm831x_clkout_set_parent,
};

static const struct clk_init_data wm831x_clkout_init = {
	.name = "clkout",
	.ops = &wm831x_clkout_ops,
	.parent_names = wm831x_clkout_parents,
	.num_parents = ARRAY_SIZE(wm831x_clkout_parents),
	.flags = CLK_SET_RATE_PARENT,
};

static int wm831x_clk_probe(struct platform_device *pdev)
{
	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
	struct wm831x_clk *clkdata;
	int ret;

	clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
	if (!clkdata)
		return -ENOMEM;

	clkdata->wm831x = wm831x;

	/* XTAL_ENA can only be set via OTP/InstantConfig so just read once */
	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
			ret);
		return ret;
	}
	clkdata->xtal_ena = ret & WM831X_XTAL_ENA;

	clkdata->xtal_hw.init = &wm831x_xtal_init;
	ret = devm_clk_hw_register(&pdev->dev, &clkdata->xtal_hw);
	if (ret)
		return ret;

	clkdata->fll_hw.init = &wm831x_fll_init;
	ret = devm_clk_hw_register(&pdev->dev, &clkdata->fll_hw);
	if (ret)
		return ret;

	clkdata->clkout_hw.init = &wm831x_clkout_init;
	ret = devm_clk_hw_register(&pdev->dev, &clkdata->clkout_hw);
	if (ret)
		return ret;

	platform_set_drvdata(pdev, clkdata);

	return 0;
}

static struct platform_driver wm831x_clk_driver = {
	.probe = wm831x_clk_probe,
	.driver		= {
		.name	= "wm831x-clk",
	},
};

module_platform_driver(wm831x_clk_driver);

/* Module information */
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM831x clock driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-clk");