tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * WM831x clock control
3 *
4 * Copyright 2011-2 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 */
14
15#include <linux/clk.h>
16#include <linux/clk-provider.h>
17#include <linux/delay.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20#include <linux/platform_device.h>
21#include <linux/mfd/wm831x/core.h>
22
23struct wm831x_clk {
24 struct wm831x *wm831x;
25 struct clk_hw xtal_hw;
26 struct clk_hw fll_hw;
27 struct clk_hw clkout_hw;
28 struct clk *xtal;
29 struct clk *fll;
30 struct clk *clkout;
31 bool xtal_ena;
32};
33
34static int wm831x_xtal_is_enabled(struct clk_hw *hw)
35{
36 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
37 xtal_hw);
38
39 return clkdata->xtal_ena;
40}
41
42static unsigned long wm831x_xtal_recalc_rate(struct clk_hw *hw,
43 unsigned long parent_rate)
44{
45 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
46 xtal_hw);
47
48 if (clkdata->xtal_ena)
49 return 32768;
50 else
51 return 0;
52}
53
54static const struct clk_ops wm831x_xtal_ops = {
55 .is_enabled = wm831x_xtal_is_enabled,
56 .recalc_rate = wm831x_xtal_recalc_rate,
57};
58
59static struct clk_init_data wm831x_xtal_init = {
60 .name = "xtal",
61 .ops = &wm831x_xtal_ops,
62 .flags = CLK_IS_ROOT,
63};
64
65static const unsigned long wm831x_fll_auto_rates[] = {
66 2048000,
67 11289600,
68 12000000,
69 12288000,
70 19200000,
71 22579600,
72 24000000,
73 24576000,
74};
75
76static int wm831x_fll_is_enabled(struct clk_hw *hw)
77{
78 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
79 fll_hw);
80 struct wm831x *wm831x = clkdata->wm831x;
81 int ret;
82
83 ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_1);
84 if (ret < 0) {
85 dev_err(wm831x->dev, "Unable to read FLL_CONTROL_1: %d\n",
86 ret);
87 return true;
88 }
89
90 return (ret & WM831X_FLL_ENA) != 0;
91}
92
93static int wm831x_fll_prepare(struct clk_hw *hw)
94{
95 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
96 fll_hw);
97 struct wm831x *wm831x = clkdata->wm831x;
98 int ret;
99
100 ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_2,
101 WM831X_FLL_ENA, WM831X_FLL_ENA);
102 if (ret != 0)
103 dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret);
104
105 usleep_range(2000, 2000);
106
107 return ret;
108}
109
110static void wm831x_fll_unprepare(struct clk_hw *hw)
111{
112 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
113 fll_hw);
114 struct wm831x *wm831x = clkdata->wm831x;
115 int ret;
116
117 ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_2, WM831X_FLL_ENA, 0);
118 if (ret != 0)
119 dev_crit(wm831x->dev, "Failed to disaable FLL: %d\n", ret);
120}
121
122static unsigned long wm831x_fll_recalc_rate(struct clk_hw *hw,
123 unsigned long parent_rate)
124{
125 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
126 fll_hw);
127 struct wm831x *wm831x = clkdata->wm831x;
128 int ret;
129
130 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
131 if (ret < 0) {
132 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
133 ret);
134 return 0;
135 }
136
137 if (ret & WM831X_FLL_AUTO)
138 return wm831x_fll_auto_rates[ret & WM831X_FLL_AUTO_FREQ_MASK];
139
140 dev_err(wm831x->dev, "FLL only supported in AUTO mode\n");
141
142 return 0;
143}
144
145static long wm831x_fll_round_rate(struct clk_hw *hw, unsigned long rate,
146 unsigned long *unused)
147{
148 int best = 0;
149 int i;
150
151 for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
152 if (abs(wm831x_fll_auto_rates[i] - rate) <
153 abs(wm831x_fll_auto_rates[best] - rate))
154 best = i;
155
156 return wm831x_fll_auto_rates[best];
157}
158
159static int wm831x_fll_set_rate(struct clk_hw *hw, unsigned long rate,
160 unsigned long parent_rate)
161{
162 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
163 fll_hw);
164 struct wm831x *wm831x = clkdata->wm831x;
165 int i;
166
167 for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
168 if (wm831x_fll_auto_rates[i] == rate)
169 break;
170 if (i == ARRAY_SIZE(wm831x_fll_auto_rates))
171 return -EINVAL;
172
173 if (wm831x_fll_is_enabled(hw))
174 return -EPERM;
175
176 return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_2,
177 WM831X_FLL_AUTO_FREQ_MASK, i);
178}
179
180static const char *wm831x_fll_parents[] = {
181 "xtal",
182 "clkin",
183};
184
185static u8 wm831x_fll_get_parent(struct clk_hw *hw)
186{
187 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
188 fll_hw);
189 struct wm831x *wm831x = clkdata->wm831x;
190 int ret;
191
192 /* AUTO mode is always clocked from the crystal */
193 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
194 if (ret < 0) {
195 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
196 ret);
197 return 0;
198 }
199
200 if (ret & WM831X_FLL_AUTO)
201 return 0;
202
203 ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_5);
204 if (ret < 0) {
205 dev_err(wm831x->dev, "Unable to read FLL_CONTROL_5: %d\n",
206 ret);
207 return 0;
208 }
209
210 switch (ret & WM831X_FLL_CLK_SRC_MASK) {
211 case 0:
212 return 0;
213 case 1:
214 return 1;
215 default:
216 dev_err(wm831x->dev, "Unsupported FLL clock source %d\n",
217 ret & WM831X_FLL_CLK_SRC_MASK);
218 return 0;
219 }
220}
221
222static const struct clk_ops wm831x_fll_ops = {
223 .is_enabled = wm831x_fll_is_enabled,
224 .prepare = wm831x_fll_prepare,
225 .unprepare = wm831x_fll_unprepare,
226 .round_rate = wm831x_fll_round_rate,
227 .recalc_rate = wm831x_fll_recalc_rate,
228 .set_rate = wm831x_fll_set_rate,
229 .get_parent = wm831x_fll_get_parent,
230};
231
232static struct clk_init_data wm831x_fll_init = {
233 .name = "fll",
234 .ops = &wm831x_fll_ops,
235 .parent_names = wm831x_fll_parents,
236 .num_parents = ARRAY_SIZE(wm831x_fll_parents),
237 .flags = CLK_SET_RATE_GATE,
238};
239
240static int wm831x_clkout_is_enabled(struct clk_hw *hw)
241{
242 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
243 clkout_hw);
244 struct wm831x *wm831x = clkdata->wm831x;
245 int ret;
246
247 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
248 if (ret < 0) {
249 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
250 ret);
251 return true;
252 }
253
254 return (ret & WM831X_CLKOUT_ENA) != 0;
255}
256
257static int wm831x_clkout_prepare(struct clk_hw *hw)
258{
259 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
260 clkout_hw);
261 struct wm831x *wm831x = clkdata->wm831x;
262 int ret;
263
264 ret = wm831x_reg_unlock(wm831x);
265 if (ret != 0) {
266 dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
267 return ret;
268 }
269
270 ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
271 WM831X_CLKOUT_ENA, WM831X_CLKOUT_ENA);
272 if (ret != 0)
273 dev_crit(wm831x->dev, "Failed to enable CLKOUT: %d\n", ret);
274
275 wm831x_reg_lock(wm831x);
276
277 return ret;
278}
279
280static void wm831x_clkout_unprepare(struct clk_hw *hw)
281{
282 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
283 clkout_hw);
284 struct wm831x *wm831x = clkdata->wm831x;
285 int ret;
286
287 ret = wm831x_reg_unlock(wm831x);
288 if (ret != 0) {
289 dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
290 return;
291 }
292
293 ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
294 WM831X_CLKOUT_ENA, 0);
295 if (ret != 0)
296 dev_crit(wm831x->dev, "Failed to disable CLKOUT: %d\n", ret);
297
298 wm831x_reg_lock(wm831x);
299}
300
301static const char *wm831x_clkout_parents[] = {
302 "xtal",
303 "fll",
304};
305
306static u8 wm831x_clkout_get_parent(struct clk_hw *hw)
307{
308 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
309 clkout_hw);
310 struct wm831x *wm831x = clkdata->wm831x;
311 int ret;
312
313 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
314 if (ret < 0) {
315 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
316 ret);
317 return 0;
318 }
319
320 if (ret & WM831X_CLKOUT_SRC)
321 return 0;
322 else
323 return 1;
324}
325
326static int wm831x_clkout_set_parent(struct clk_hw *hw, u8 parent)
327{
328 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
329 clkout_hw);
330 struct wm831x *wm831x = clkdata->wm831x;
331
332 return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
333 WM831X_CLKOUT_SRC,
334 parent << WM831X_CLKOUT_SRC_SHIFT);
335}
336
337static const struct clk_ops wm831x_clkout_ops = {
338 .is_enabled = wm831x_clkout_is_enabled,
339 .prepare = wm831x_clkout_prepare,
340 .unprepare = wm831x_clkout_unprepare,
341 .get_parent = wm831x_clkout_get_parent,
342 .set_parent = wm831x_clkout_set_parent,
343};
344
345static struct clk_init_data wm831x_clkout_init = {
346 .name = "clkout",
347 .ops = &wm831x_clkout_ops,
348 .parent_names = wm831x_clkout_parents,
349 .num_parents = ARRAY_SIZE(wm831x_clkout_parents),
350 .flags = CLK_SET_RATE_PARENT,
351};
352
353static int wm831x_clk_probe(struct platform_device *pdev)
354{
355 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
356 struct wm831x_clk *clkdata;
357 int ret;
358
359 clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
360 if (!clkdata)
361 return -ENOMEM;
362
363 /* XTAL_ENA can only be set via OTP/InstantConfig so just read once */
364 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
365 if (ret < 0) {
366 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
367 ret);
368 return ret;
369 }
370 clkdata->xtal_ena = ret & WM831X_XTAL_ENA;
371
372 clkdata->xtal_hw.init = &wm831x_xtal_init;
373 clkdata->xtal = devm_clk_register(&pdev->dev, &clkdata->xtal_hw);
374 if (IS_ERR(clkdata->xtal))
375 return PTR_ERR(clkdata->xtal);
376
377 clkdata->fll_hw.init = &wm831x_fll_init;
378 clkdata->fll = devm_clk_register(&pdev->dev, &clkdata->fll_hw);
379 if (IS_ERR(clkdata->fll))
380 return PTR_ERR(clkdata->fll);
381
382 clkdata->clkout_hw.init = &wm831x_clkout_init;
383 clkdata->clkout = devm_clk_register(&pdev->dev, &clkdata->clkout_hw);
384 if (IS_ERR(clkdata->clkout))
385 return PTR_ERR(clkdata->clkout);
386
387 dev_set_drvdata(&pdev->dev, clkdata);
388
389 return 0;
390}
391
392static int wm831x_clk_remove(struct platform_device *pdev)
393{
394 return 0;
395}
396
397static struct platform_driver wm831x_clk_driver = {
398 .probe = wm831x_clk_probe,
399 .remove = wm831x_clk_remove,
400 .driver = {
401 .name = "wm831x-clk",
402 .owner = THIS_MODULE,
403 },
404};
405
406module_platform_driver(wm831x_clk_driver);
407
408/* Module information */
409MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
410MODULE_DESCRIPTION("WM831x clock driver");
411MODULE_LICENSE("GPL");
412MODULE_ALIAS("platform:wm831x-clk");