1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * WM831x clock control
4 *
5 * Copyright 2011-2 Wolfson Microelectronics PLC.
6 *
7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 */
9
10 #include <linux/clk-provider.h>
11 #include <linux/delay.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/platform_device.h>
15 #include <linux/mfd/wm831x/core.h>
16
17 struct wm831x_clk {
18 struct wm831x *wm831x;
19 struct clk_hw xtal_hw;
20 struct clk_hw fll_hw;
21 struct clk_hw clkout_hw;
22 bool xtal_ena;
23 };
24
wm831x_xtal_is_prepared(struct clk_hw * hw)25 static int wm831x_xtal_is_prepared(struct clk_hw *hw)
26 {
27 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
28 xtal_hw);
29
30 return clkdata->xtal_ena;
31 }
32
wm831x_xtal_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)33 static unsigned long wm831x_xtal_recalc_rate(struct clk_hw *hw,
34 unsigned long parent_rate)
35 {
36 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
37 xtal_hw);
38
39 if (clkdata->xtal_ena)
40 return 32768;
41 else
42 return 0;
43 }
44
45 static const struct clk_ops wm831x_xtal_ops = {
46 .is_prepared = wm831x_xtal_is_prepared,
47 .recalc_rate = wm831x_xtal_recalc_rate,
48 };
49
50 static const struct clk_init_data wm831x_xtal_init = {
51 .name = "xtal",
52 .ops = &wm831x_xtal_ops,
53 };
54
55 static const unsigned long wm831x_fll_auto_rates[] = {
56 2048000,
57 11289600,
58 12000000,
59 12288000,
60 19200000,
61 22579600,
62 24000000,
63 24576000,
64 };
65
wm831x_fll_is_prepared(struct clk_hw * hw)66 static int wm831x_fll_is_prepared(struct clk_hw *hw)
67 {
68 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
69 fll_hw);
70 struct wm831x *wm831x = clkdata->wm831x;
71 int ret;
72
73 ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_1);
74 if (ret < 0) {
75 dev_err(wm831x->dev, "Unable to read FLL_CONTROL_1: %d\n",
76 ret);
77 return true;
78 }
79
80 return (ret & WM831X_FLL_ENA) != 0;
81 }
82
wm831x_fll_prepare(struct clk_hw * hw)83 static int wm831x_fll_prepare(struct clk_hw *hw)
84 {
85 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
86 fll_hw);
87 struct wm831x *wm831x = clkdata->wm831x;
88 int ret;
89
90 ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1,
91 WM831X_FLL_ENA, WM831X_FLL_ENA);
92 if (ret != 0)
93 dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret);
94
95 /* wait 2-3 ms for new frequency taking effect */
96 usleep_range(2000, 3000);
97
98 return ret;
99 }
100
wm831x_fll_unprepare(struct clk_hw * hw)101 static void wm831x_fll_unprepare(struct clk_hw *hw)
102 {
103 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
104 fll_hw);
105 struct wm831x *wm831x = clkdata->wm831x;
106 int ret;
107
108 ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1, WM831X_FLL_ENA, 0);
109 if (ret != 0)
110 dev_crit(wm831x->dev, "Failed to disable FLL: %d\n", ret);
111 }
112
wm831x_fll_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)113 static unsigned long wm831x_fll_recalc_rate(struct clk_hw *hw,
114 unsigned long parent_rate)
115 {
116 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
117 fll_hw);
118 struct wm831x *wm831x = clkdata->wm831x;
119 int ret;
120
121 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
122 if (ret < 0) {
123 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
124 ret);
125 return 0;
126 }
127
128 if (ret & WM831X_FLL_AUTO)
129 return wm831x_fll_auto_rates[ret & WM831X_FLL_AUTO_FREQ_MASK];
130
131 dev_err(wm831x->dev, "FLL only supported in AUTO mode\n");
132
133 return 0;
134 }
135
wm831x_fll_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * unused)136 static long wm831x_fll_round_rate(struct clk_hw *hw, unsigned long rate,
137 unsigned long *unused)
138 {
139 int best = 0;
140 int i;
141
142 for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
143 if (abs(wm831x_fll_auto_rates[i] - rate) <
144 abs(wm831x_fll_auto_rates[best] - rate))
145 best = i;
146
147 return wm831x_fll_auto_rates[best];
148 }
149
wm831x_fll_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)150 static int wm831x_fll_set_rate(struct clk_hw *hw, unsigned long rate,
151 unsigned long parent_rate)
152 {
153 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
154 fll_hw);
155 struct wm831x *wm831x = clkdata->wm831x;
156 int i;
157
158 for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
159 if (wm831x_fll_auto_rates[i] == rate)
160 break;
161 if (i == ARRAY_SIZE(wm831x_fll_auto_rates))
162 return -EINVAL;
163
164 if (wm831x_fll_is_prepared(hw))
165 return -EPERM;
166
167 return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_2,
168 WM831X_FLL_AUTO_FREQ_MASK, i);
169 }
170
171 static const char *wm831x_fll_parents[] = {
172 "xtal",
173 "clkin",
174 };
175
wm831x_fll_get_parent(struct clk_hw * hw)176 static u8 wm831x_fll_get_parent(struct clk_hw *hw)
177 {
178 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
179 fll_hw);
180 struct wm831x *wm831x = clkdata->wm831x;
181 int ret;
182
183 /* AUTO mode is always clocked from the crystal */
184 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
185 if (ret < 0) {
186 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
187 ret);
188 return 0;
189 }
190
191 if (ret & WM831X_FLL_AUTO)
192 return 0;
193
194 ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_5);
195 if (ret < 0) {
196 dev_err(wm831x->dev, "Unable to read FLL_CONTROL_5: %d\n",
197 ret);
198 return 0;
199 }
200
201 switch (ret & WM831X_FLL_CLK_SRC_MASK) {
202 case 0:
203 return 0;
204 case 1:
205 return 1;
206 default:
207 dev_err(wm831x->dev, "Unsupported FLL clock source %d\n",
208 ret & WM831X_FLL_CLK_SRC_MASK);
209 return 0;
210 }
211 }
212
213 static const struct clk_ops wm831x_fll_ops = {
214 .is_prepared = wm831x_fll_is_prepared,
215 .prepare = wm831x_fll_prepare,
216 .unprepare = wm831x_fll_unprepare,
217 .round_rate = wm831x_fll_round_rate,
218 .recalc_rate = wm831x_fll_recalc_rate,
219 .set_rate = wm831x_fll_set_rate,
220 .get_parent = wm831x_fll_get_parent,
221 };
222
223 static const struct clk_init_data wm831x_fll_init = {
224 .name = "fll",
225 .ops = &wm831x_fll_ops,
226 .parent_names = wm831x_fll_parents,
227 .num_parents = ARRAY_SIZE(wm831x_fll_parents),
228 .flags = CLK_SET_RATE_GATE,
229 };
230
wm831x_clkout_is_prepared(struct clk_hw * hw)231 static int wm831x_clkout_is_prepared(struct clk_hw *hw)
232 {
233 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
234 clkout_hw);
235 struct wm831x *wm831x = clkdata->wm831x;
236 int ret;
237
238 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
239 if (ret < 0) {
240 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
241 ret);
242 return false;
243 }
244
245 return (ret & WM831X_CLKOUT_ENA) != 0;
246 }
247
wm831x_clkout_prepare(struct clk_hw * hw)248 static int wm831x_clkout_prepare(struct clk_hw *hw)
249 {
250 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
251 clkout_hw);
252 struct wm831x *wm831x = clkdata->wm831x;
253 int ret;
254
255 ret = wm831x_reg_unlock(wm831x);
256 if (ret != 0) {
257 dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
258 return ret;
259 }
260
261 ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
262 WM831X_CLKOUT_ENA, WM831X_CLKOUT_ENA);
263 if (ret != 0)
264 dev_crit(wm831x->dev, "Failed to enable CLKOUT: %d\n", ret);
265
266 wm831x_reg_lock(wm831x);
267
268 return ret;
269 }
270
wm831x_clkout_unprepare(struct clk_hw * hw)271 static void wm831x_clkout_unprepare(struct clk_hw *hw)
272 {
273 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
274 clkout_hw);
275 struct wm831x *wm831x = clkdata->wm831x;
276 int ret;
277
278 ret = wm831x_reg_unlock(wm831x);
279 if (ret != 0) {
280 dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
281 return;
282 }
283
284 ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
285 WM831X_CLKOUT_ENA, 0);
286 if (ret != 0)
287 dev_crit(wm831x->dev, "Failed to disable CLKOUT: %d\n", ret);
288
289 wm831x_reg_lock(wm831x);
290 }
291
292 static const char *wm831x_clkout_parents[] = {
293 "fll",
294 "xtal",
295 };
296
wm831x_clkout_get_parent(struct clk_hw * hw)297 static u8 wm831x_clkout_get_parent(struct clk_hw *hw)
298 {
299 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
300 clkout_hw);
301 struct wm831x *wm831x = clkdata->wm831x;
302 int ret;
303
304 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
305 if (ret < 0) {
306 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
307 ret);
308 return 0;
309 }
310
311 if (ret & WM831X_CLKOUT_SRC)
312 return 1;
313 else
314 return 0;
315 }
316
wm831x_clkout_set_parent(struct clk_hw * hw,u8 parent)317 static int wm831x_clkout_set_parent(struct clk_hw *hw, u8 parent)
318 {
319 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
320 clkout_hw);
321 struct wm831x *wm831x = clkdata->wm831x;
322
323 return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
324 WM831X_CLKOUT_SRC,
325 parent << WM831X_CLKOUT_SRC_SHIFT);
326 }
327
328 static const struct clk_ops wm831x_clkout_ops = {
329 .is_prepared = wm831x_clkout_is_prepared,
330 .prepare = wm831x_clkout_prepare,
331 .unprepare = wm831x_clkout_unprepare,
332 .determine_rate = clk_hw_determine_rate_no_reparent,
333 .get_parent = wm831x_clkout_get_parent,
334 .set_parent = wm831x_clkout_set_parent,
335 };
336
337 static const struct clk_init_data wm831x_clkout_init = {
338 .name = "clkout",
339 .ops = &wm831x_clkout_ops,
340 .parent_names = wm831x_clkout_parents,
341 .num_parents = ARRAY_SIZE(wm831x_clkout_parents),
342 .flags = CLK_SET_RATE_PARENT,
343 };
344
wm831x_clk_probe(struct platform_device * pdev)345 static int wm831x_clk_probe(struct platform_device *pdev)
346 {
347 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
348 struct wm831x_clk *clkdata;
349 int ret;
350
351 clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
352 if (!clkdata)
353 return -ENOMEM;
354
355 clkdata->wm831x = wm831x;
356
357 /* XTAL_ENA can only be set via OTP/InstantConfig so just read once */
358 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
359 if (ret < 0) {
360 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
361 ret);
362 return ret;
363 }
364 clkdata->xtal_ena = ret & WM831X_XTAL_ENA;
365
366 clkdata->xtal_hw.init = &wm831x_xtal_init;
367 ret = devm_clk_hw_register(&pdev->dev, &clkdata->xtal_hw);
368 if (ret)
369 return ret;
370
371 clkdata->fll_hw.init = &wm831x_fll_init;
372 ret = devm_clk_hw_register(&pdev->dev, &clkdata->fll_hw);
373 if (ret)
374 return ret;
375
376 clkdata->clkout_hw.init = &wm831x_clkout_init;
377 ret = devm_clk_hw_register(&pdev->dev, &clkdata->clkout_hw);
378 if (ret)
379 return ret;
380
381 platform_set_drvdata(pdev, clkdata);
382
383 return 0;
384 }
385
386 static struct platform_driver wm831x_clk_driver = {
387 .probe = wm831x_clk_probe,
388 .driver = {
389 .name = "wm831x-clk",
390 },
391 };
392
393 module_platform_driver(wm831x_clk_driver);
394
395 /* Module information */
396 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
397 MODULE_DESCRIPTION("WM831x clock driver");
398 MODULE_LICENSE("GPL");
399 MODULE_ALIAS("platform:wm831x-clk");
400