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-provider.h>
16#include <linux/delay.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/platform_device.h>
20#include <linux/mfd/wm831x/core.h>
21
22struct wm831x_clk {
23 struct wm831x *wm831x;
24 struct clk_hw xtal_hw;
25 struct clk_hw fll_hw;
26 struct clk_hw clkout_hw;
27 bool xtal_ena;
28};
29
30static int wm831x_xtal_is_prepared(struct clk_hw *hw)
31{
32 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
33 xtal_hw);
34
35 return clkdata->xtal_ena;
36}
37
38static unsigned long wm831x_xtal_recalc_rate(struct clk_hw *hw,
39 unsigned long parent_rate)
40{
41 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
42 xtal_hw);
43
44 if (clkdata->xtal_ena)
45 return 32768;
46 else
47 return 0;
48}
49
50static const struct clk_ops wm831x_xtal_ops = {
51 .is_prepared = wm831x_xtal_is_prepared,
52 .recalc_rate = wm831x_xtal_recalc_rate,
53};
54
55static const struct clk_init_data wm831x_xtal_init = {
56 .name = "xtal",
57 .ops = &wm831x_xtal_ops,
58};
59
60static const unsigned long wm831x_fll_auto_rates[] = {
61 2048000,
62 11289600,
63 12000000,
64 12288000,
65 19200000,
66 22579600,
67 24000000,
68 24576000,
69};
70
71static int wm831x_fll_is_prepared(struct clk_hw *hw)
72{
73 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
74 fll_hw);
75 struct wm831x *wm831x = clkdata->wm831x;
76 int ret;
77
78 ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_1);
79 if (ret < 0) {
80 dev_err(wm831x->dev, "Unable to read FLL_CONTROL_1: %d\n",
81 ret);
82 return true;
83 }
84
85 return (ret & WM831X_FLL_ENA) != 0;
86}
87
88static int wm831x_fll_prepare(struct clk_hw *hw)
89{
90 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
91 fll_hw);
92 struct wm831x *wm831x = clkdata->wm831x;
93 int ret;
94
95 ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1,
96 WM831X_FLL_ENA, WM831X_FLL_ENA);
97 if (ret != 0)
98 dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret);
99
100 /* wait 2-3 ms for new frequency taking effect */
101 usleep_range(2000, 3000);
102
103 return ret;
104}
105
106static void wm831x_fll_unprepare(struct clk_hw *hw)
107{
108 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
109 fll_hw);
110 struct wm831x *wm831x = clkdata->wm831x;
111 int ret;
112
113 ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1, WM831X_FLL_ENA, 0);
114 if (ret != 0)
115 dev_crit(wm831x->dev, "Failed to disable FLL: %d\n", ret);
116}
117
118static unsigned long wm831x_fll_recalc_rate(struct clk_hw *hw,
119 unsigned long parent_rate)
120{
121 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
122 fll_hw);
123 struct wm831x *wm831x = clkdata->wm831x;
124 int ret;
125
126 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
127 if (ret < 0) {
128 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
129 ret);
130 return 0;
131 }
132
133 if (ret & WM831X_FLL_AUTO)
134 return wm831x_fll_auto_rates[ret & WM831X_FLL_AUTO_FREQ_MASK];
135
136 dev_err(wm831x->dev, "FLL only supported in AUTO mode\n");
137
138 return 0;
139}
140
141static long wm831x_fll_round_rate(struct clk_hw *hw, unsigned long rate,
142 unsigned long *unused)
143{
144 int best = 0;
145 int i;
146
147 for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
148 if (abs(wm831x_fll_auto_rates[i] - rate) <
149 abs(wm831x_fll_auto_rates[best] - rate))
150 best = i;
151
152 return wm831x_fll_auto_rates[best];
153}
154
155static int wm831x_fll_set_rate(struct clk_hw *hw, unsigned long rate,
156 unsigned long parent_rate)
157{
158 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
159 fll_hw);
160 struct wm831x *wm831x = clkdata->wm831x;
161 int i;
162
163 for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
164 if (wm831x_fll_auto_rates[i] == rate)
165 break;
166 if (i == ARRAY_SIZE(wm831x_fll_auto_rates))
167 return -EINVAL;
168
169 if (wm831x_fll_is_prepared(hw))
170 return -EPERM;
171
172 return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_2,
173 WM831X_FLL_AUTO_FREQ_MASK, i);
174}
175
176static const char *wm831x_fll_parents[] = {
177 "xtal",
178 "clkin",
179};
180
181static u8 wm831x_fll_get_parent(struct clk_hw *hw)
182{
183 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
184 fll_hw);
185 struct wm831x *wm831x = clkdata->wm831x;
186 int ret;
187
188 /* AUTO mode is always clocked from the crystal */
189 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
190 if (ret < 0) {
191 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
192 ret);
193 return 0;
194 }
195
196 if (ret & WM831X_FLL_AUTO)
197 return 0;
198
199 ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_5);
200 if (ret < 0) {
201 dev_err(wm831x->dev, "Unable to read FLL_CONTROL_5: %d\n",
202 ret);
203 return 0;
204 }
205
206 switch (ret & WM831X_FLL_CLK_SRC_MASK) {
207 case 0:
208 return 0;
209 case 1:
210 return 1;
211 default:
212 dev_err(wm831x->dev, "Unsupported FLL clock source %d\n",
213 ret & WM831X_FLL_CLK_SRC_MASK);
214 return 0;
215 }
216}
217
218static const struct clk_ops wm831x_fll_ops = {
219 .is_prepared = wm831x_fll_is_prepared,
220 .prepare = wm831x_fll_prepare,
221 .unprepare = wm831x_fll_unprepare,
222 .round_rate = wm831x_fll_round_rate,
223 .recalc_rate = wm831x_fll_recalc_rate,
224 .set_rate = wm831x_fll_set_rate,
225 .get_parent = wm831x_fll_get_parent,
226};
227
228static const struct clk_init_data wm831x_fll_init = {
229 .name = "fll",
230 .ops = &wm831x_fll_ops,
231 .parent_names = wm831x_fll_parents,
232 .num_parents = ARRAY_SIZE(wm831x_fll_parents),
233 .flags = CLK_SET_RATE_GATE,
234};
235
236static int wm831x_clkout_is_prepared(struct clk_hw *hw)
237{
238 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
239 clkout_hw);
240 struct wm831x *wm831x = clkdata->wm831x;
241 int ret;
242
243 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
244 if (ret < 0) {
245 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
246 ret);
247 return false;
248 }
249
250 return (ret & WM831X_CLKOUT_ENA) != 0;
251}
252
253static int wm831x_clkout_prepare(struct clk_hw *hw)
254{
255 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
256 clkout_hw);
257 struct wm831x *wm831x = clkdata->wm831x;
258 int ret;
259
260 ret = wm831x_reg_unlock(wm831x);
261 if (ret != 0) {
262 dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
263 return ret;
264 }
265
266 ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
267 WM831X_CLKOUT_ENA, WM831X_CLKOUT_ENA);
268 if (ret != 0)
269 dev_crit(wm831x->dev, "Failed to enable CLKOUT: %d\n", ret);
270
271 wm831x_reg_lock(wm831x);
272
273 return ret;
274}
275
276static void wm831x_clkout_unprepare(struct clk_hw *hw)
277{
278 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
279 clkout_hw);
280 struct wm831x *wm831x = clkdata->wm831x;
281 int ret;
282
283 ret = wm831x_reg_unlock(wm831x);
284 if (ret != 0) {
285 dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
286 return;
287 }
288
289 ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
290 WM831X_CLKOUT_ENA, 0);
291 if (ret != 0)
292 dev_crit(wm831x->dev, "Failed to disable CLKOUT: %d\n", ret);
293
294 wm831x_reg_lock(wm831x);
295}
296
297static const char *wm831x_clkout_parents[] = {
298 "fll",
299 "xtal",
300};
301
302static u8 wm831x_clkout_get_parent(struct clk_hw *hw)
303{
304 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
305 clkout_hw);
306 struct wm831x *wm831x = clkdata->wm831x;
307 int ret;
308
309 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
310 if (ret < 0) {
311 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
312 ret);
313 return 0;
314 }
315
316 if (ret & WM831X_CLKOUT_SRC)
317 return 1;
318 else
319 return 0;
320}
321
322static int wm831x_clkout_set_parent(struct clk_hw *hw, u8 parent)
323{
324 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
325 clkout_hw);
326 struct wm831x *wm831x = clkdata->wm831x;
327
328 return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
329 WM831X_CLKOUT_SRC,
330 parent << WM831X_CLKOUT_SRC_SHIFT);
331}
332
333static const struct clk_ops wm831x_clkout_ops = {
334 .is_prepared = wm831x_clkout_is_prepared,
335 .prepare = wm831x_clkout_prepare,
336 .unprepare = wm831x_clkout_unprepare,
337 .get_parent = wm831x_clkout_get_parent,
338 .set_parent = wm831x_clkout_set_parent,
339};
340
341static const struct clk_init_data wm831x_clkout_init = {
342 .name = "clkout",
343 .ops = &wm831x_clkout_ops,
344 .parent_names = wm831x_clkout_parents,
345 .num_parents = ARRAY_SIZE(wm831x_clkout_parents),
346 .flags = CLK_SET_RATE_PARENT,
347};
348
349static int wm831x_clk_probe(struct platform_device *pdev)
350{
351 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
352 struct wm831x_clk *clkdata;
353 int ret;
354
355 clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
356 if (!clkdata)
357 return -ENOMEM;
358
359 clkdata->wm831x = wm831x;
360
361 /* XTAL_ENA can only be set via OTP/InstantConfig so just read once */
362 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
363 if (ret < 0) {
364 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
365 ret);
366 return ret;
367 }
368 clkdata->xtal_ena = ret & WM831X_XTAL_ENA;
369
370 clkdata->xtal_hw.init = &wm831x_xtal_init;
371 ret = devm_clk_hw_register(&pdev->dev, &clkdata->xtal_hw);
372 if (ret)
373 return ret;
374
375 clkdata->fll_hw.init = &wm831x_fll_init;
376 ret = devm_clk_hw_register(&pdev->dev, &clkdata->fll_hw);
377 if (ret)
378 return ret;
379
380 clkdata->clkout_hw.init = &wm831x_clkout_init;
381 ret = devm_clk_hw_register(&pdev->dev, &clkdata->clkout_hw);
382 if (ret)
383 return ret;
384
385 platform_set_drvdata(pdev, clkdata);
386
387 return 0;
388}
389
390static struct platform_driver wm831x_clk_driver = {
391 .probe = wm831x_clk_probe,
392 .driver = {
393 .name = "wm831x-clk",
394 },
395};
396
397module_platform_driver(wm831x_clk_driver);
398
399/* Module information */
400MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
401MODULE_DESCRIPTION("WM831x clock driver");
402MODULE_LICENSE("GPL");
403MODULE_ALIAS("platform:wm831x-clk");