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64dfbe24 KM |
1 | /* |
2 | * CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier | |
3 | * | |
4 | * Copyright (C) 2015 Renesas Electronics Corporation | |
5 | * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | #include <linux/clk-provider.h> | |
12 | #include <linux/delay.h> | |
13 | #include <linux/clk.h> | |
14 | #include <linux/i2c.h> | |
15 | #include <linux/of_device.h> | |
16 | #include <linux/module.h> | |
17 | ||
18 | #define CH_MAX 4 | |
19 | #define RATIO_REG_SIZE 4 | |
20 | ||
21 | #define DEVICE_ID 0x1 | |
22 | #define DEVICE_CTRL 0x2 | |
23 | #define DEVICE_CFG1 0x3 | |
24 | #define DEVICE_CFG2 0x4 | |
25 | #define GLOBAL_CFG 0x5 | |
26 | #define Ratio_Add(x, nth) (6 + (x * 4) + (nth)) | |
27 | #define Ratio_Val(x, nth) ((x >> (24 - (8 * nth))) & 0xFF) | |
28 | #define Val_Ratio(x, nth) ((x & 0xFF) << (24 - (8 * nth))) | |
29 | #define FUNC_CFG1 0x16 | |
30 | #define FUNC_CFG2 0x17 | |
31 | ||
32 | /* DEVICE_ID */ | |
33 | #define REVISION_MASK (0x7) | |
34 | #define REVISION_B2_B3 (0x4) | |
35 | #define REVISION_C1 (0x6) | |
36 | ||
37 | /* DEVICE_CTRL */ | |
38 | #define PLL_UNLOCK (1 << 7) | |
39 | ||
40 | /* DEVICE_CFG1 */ | |
41 | #define RSEL(x) (((x) & 0x3) << 3) | |
42 | #define RSEL_MASK RSEL(0x3) | |
43 | #define ENDEV1 (0x1) | |
44 | ||
45 | /* GLOBAL_CFG */ | |
46 | #define ENDEV2 (0x1) | |
47 | ||
48 | #define CH_SIZE_ERR(ch) ((ch < 0) || (ch >= CH_MAX)) | |
49 | #define hw_to_priv(_hw) container_of(_hw, struct cs2000_priv, hw) | |
50 | #define priv_to_client(priv) (priv->client) | |
51 | #define priv_to_dev(priv) (&(priv_to_client(priv)->dev)) | |
52 | ||
53 | #define CLK_IN 0 | |
54 | #define REF_CLK 1 | |
55 | #define CLK_MAX 2 | |
56 | ||
57 | struct cs2000_priv { | |
58 | struct clk_hw hw; | |
59 | struct i2c_client *client; | |
60 | struct clk *clk_in; | |
61 | struct clk *ref_clk; | |
64dfbe24 KM |
62 | }; |
63 | ||
64 | static const struct of_device_id cs2000_of_match[] = { | |
65 | { .compatible = "cirrus,cs2000-cp", }, | |
66 | {}, | |
67 | }; | |
68 | MODULE_DEVICE_TABLE(of, cs2000_of_match); | |
69 | ||
70 | static const struct i2c_device_id cs2000_id[] = { | |
71 | { "cs2000-cp", }, | |
72 | {} | |
73 | }; | |
74 | MODULE_DEVICE_TABLE(i2c, cs2000_id); | |
75 | ||
76 | #define cs2000_read(priv, addr) \ | |
77 | i2c_smbus_read_byte_data(priv_to_client(priv), addr) | |
78 | #define cs2000_write(priv, addr, val) \ | |
79 | i2c_smbus_write_byte_data(priv_to_client(priv), addr, val) | |
80 | ||
81 | static int cs2000_bset(struct cs2000_priv *priv, u8 addr, u8 mask, u8 val) | |
82 | { | |
83 | s32 data; | |
84 | ||
85 | data = cs2000_read(priv, addr); | |
86 | if (data < 0) | |
87 | return data; | |
88 | ||
89 | data &= ~mask; | |
90 | data |= (val & mask); | |
91 | ||
92 | return cs2000_write(priv, addr, data); | |
93 | } | |
94 | ||
95 | static int cs2000_enable_dev_config(struct cs2000_priv *priv, bool enable) | |
96 | { | |
97 | int ret; | |
98 | ||
99 | ret = cs2000_bset(priv, DEVICE_CFG1, ENDEV1, | |
100 | enable ? ENDEV1 : 0); | |
101 | if (ret < 0) | |
102 | return ret; | |
103 | ||
104 | ret = cs2000_bset(priv, GLOBAL_CFG, ENDEV2, | |
105 | enable ? ENDEV2 : 0); | |
106 | if (ret < 0) | |
107 | return ret; | |
108 | ||
109 | return 0; | |
110 | } | |
111 | ||
112 | static int cs2000_clk_in_bound_rate(struct cs2000_priv *priv, | |
113 | u32 rate_in) | |
114 | { | |
115 | u32 val; | |
116 | ||
117 | if (rate_in >= 32000000 && rate_in < 56000000) | |
118 | val = 0x0; | |
119 | else if (rate_in >= 16000000 && rate_in < 28000000) | |
120 | val = 0x1; | |
121 | else if (rate_in >= 8000000 && rate_in < 14000000) | |
122 | val = 0x2; | |
123 | else | |
124 | return -EINVAL; | |
125 | ||
126 | return cs2000_bset(priv, FUNC_CFG1, 0x3 << 3, val << 3); | |
127 | } | |
128 | ||
129 | static int cs2000_wait_pll_lock(struct cs2000_priv *priv) | |
130 | { | |
131 | struct device *dev = priv_to_dev(priv); | |
132 | s32 val; | |
133 | unsigned int i; | |
134 | ||
135 | for (i = 0; i < 256; i++) { | |
136 | val = cs2000_read(priv, DEVICE_CTRL); | |
137 | if (val < 0) | |
138 | return val; | |
139 | if (!(val & PLL_UNLOCK)) | |
140 | return 0; | |
141 | udelay(1); | |
142 | } | |
143 | ||
144 | dev_err(dev, "pll lock failed\n"); | |
145 | ||
146 | return -ETIMEDOUT; | |
147 | } | |
148 | ||
149 | static int cs2000_clk_out_enable(struct cs2000_priv *priv, bool enable) | |
150 | { | |
151 | /* enable both AUX_OUT, CLK_OUT */ | |
152 | return cs2000_write(priv, DEVICE_CTRL, enable ? 0 : 0x3); | |
153 | } | |
154 | ||
155 | static u32 cs2000_rate_to_ratio(u32 rate_in, u32 rate_out) | |
156 | { | |
157 | u64 ratio; | |
158 | ||
159 | /* | |
160 | * ratio = rate_out / rate_in * 2^20 | |
161 | * | |
162 | * To avoid over flow, rate_out is u64. | |
163 | * The result should be u32. | |
164 | */ | |
165 | ratio = (u64)rate_out << 20; | |
166 | do_div(ratio, rate_in); | |
167 | ||
168 | return ratio; | |
169 | } | |
170 | ||
171 | static unsigned long cs2000_ratio_to_rate(u32 ratio, u32 rate_in) | |
172 | { | |
173 | u64 rate_out; | |
174 | ||
175 | /* | |
176 | * ratio = rate_out / rate_in * 2^20 | |
177 | * | |
178 | * To avoid over flow, rate_out is u64. | |
179 | * The result should be u32 or unsigned long. | |
180 | */ | |
181 | ||
182 | rate_out = (u64)ratio * rate_in; | |
183 | return rate_out >> 20; | |
184 | } | |
185 | ||
186 | static int cs2000_ratio_set(struct cs2000_priv *priv, | |
187 | int ch, u32 rate_in, u32 rate_out) | |
188 | { | |
189 | u32 val; | |
190 | unsigned int i; | |
191 | int ret; | |
192 | ||
193 | if (CH_SIZE_ERR(ch)) | |
194 | return -EINVAL; | |
195 | ||
196 | val = cs2000_rate_to_ratio(rate_in, rate_out); | |
197 | for (i = 0; i < RATIO_REG_SIZE; i++) { | |
198 | ret = cs2000_write(priv, | |
199 | Ratio_Add(ch, i), | |
200 | Ratio_Val(val, i)); | |
201 | if (ret < 0) | |
202 | return ret; | |
203 | } | |
204 | ||
205 | return 0; | |
206 | } | |
207 | ||
208 | static u32 cs2000_ratio_get(struct cs2000_priv *priv, int ch) | |
209 | { | |
210 | s32 tmp; | |
211 | u32 val; | |
212 | unsigned int i; | |
213 | ||
214 | val = 0; | |
215 | for (i = 0; i < RATIO_REG_SIZE; i++) { | |
216 | tmp = cs2000_read(priv, Ratio_Add(ch, i)); | |
217 | if (tmp < 0) | |
218 | return 0; | |
219 | ||
220 | val |= Val_Ratio(tmp, i); | |
221 | } | |
222 | ||
223 | return val; | |
224 | } | |
225 | ||
226 | static int cs2000_ratio_select(struct cs2000_priv *priv, int ch) | |
227 | { | |
228 | int ret; | |
229 | ||
230 | if (CH_SIZE_ERR(ch)) | |
231 | return -EINVAL; | |
232 | ||
233 | /* | |
234 | * FIXME | |
235 | * | |
236 | * this driver supports static ratio mode only at this point. | |
237 | */ | |
238 | ret = cs2000_bset(priv, DEVICE_CFG1, RSEL_MASK, RSEL(ch)); | |
239 | if (ret < 0) | |
240 | return ret; | |
241 | ||
242 | ret = cs2000_write(priv, DEVICE_CFG2, 0x0); | |
243 | if (ret < 0) | |
244 | return ret; | |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
249 | static unsigned long cs2000_recalc_rate(struct clk_hw *hw, | |
250 | unsigned long parent_rate) | |
251 | { | |
252 | struct cs2000_priv *priv = hw_to_priv(hw); | |
253 | int ch = 0; /* it uses ch0 only at this point */ | |
254 | u32 ratio; | |
255 | ||
256 | ratio = cs2000_ratio_get(priv, ch); | |
257 | ||
258 | return cs2000_ratio_to_rate(ratio, parent_rate); | |
259 | } | |
260 | ||
261 | static long cs2000_round_rate(struct clk_hw *hw, unsigned long rate, | |
262 | unsigned long *parent_rate) | |
263 | { | |
264 | u32 ratio; | |
265 | ||
266 | ratio = cs2000_rate_to_ratio(*parent_rate, rate); | |
267 | ||
268 | return cs2000_ratio_to_rate(ratio, *parent_rate); | |
269 | } | |
270 | ||
271 | static int __cs2000_set_rate(struct cs2000_priv *priv, int ch, | |
272 | unsigned long rate, unsigned long parent_rate) | |
273 | ||
274 | { | |
275 | int ret; | |
276 | ||
277 | ret = cs2000_clk_in_bound_rate(priv, parent_rate); | |
278 | if (ret < 0) | |
279 | return ret; | |
280 | ||
281 | ret = cs2000_ratio_set(priv, ch, parent_rate, rate); | |
282 | if (ret < 0) | |
283 | return ret; | |
284 | ||
285 | ret = cs2000_ratio_select(priv, ch); | |
286 | if (ret < 0) | |
287 | return ret; | |
288 | ||
289 | return 0; | |
290 | } | |
291 | ||
292 | static int cs2000_set_rate(struct clk_hw *hw, | |
293 | unsigned long rate, unsigned long parent_rate) | |
294 | { | |
295 | struct cs2000_priv *priv = hw_to_priv(hw); | |
296 | int ch = 0; /* it uses ch0 only at this point */ | |
297 | ||
298 | return __cs2000_set_rate(priv, ch, rate, parent_rate); | |
299 | } | |
300 | ||
301 | static int cs2000_enable(struct clk_hw *hw) | |
302 | { | |
303 | struct cs2000_priv *priv = hw_to_priv(hw); | |
304 | int ret; | |
305 | ||
306 | ret = cs2000_enable_dev_config(priv, true); | |
307 | if (ret < 0) | |
308 | return ret; | |
309 | ||
310 | ret = cs2000_clk_out_enable(priv, true); | |
311 | if (ret < 0) | |
312 | return ret; | |
313 | ||
314 | ret = cs2000_wait_pll_lock(priv); | |
315 | if (ret < 0) | |
316 | return ret; | |
317 | ||
318 | return ret; | |
319 | } | |
320 | ||
321 | static void cs2000_disable(struct clk_hw *hw) | |
322 | { | |
323 | struct cs2000_priv *priv = hw_to_priv(hw); | |
324 | ||
325 | cs2000_enable_dev_config(priv, false); | |
326 | ||
327 | cs2000_clk_out_enable(priv, false); | |
328 | } | |
329 | ||
330 | static u8 cs2000_get_parent(struct clk_hw *hw) | |
331 | { | |
332 | /* always return REF_CLK */ | |
333 | return REF_CLK; | |
334 | } | |
335 | ||
336 | static const struct clk_ops cs2000_ops = { | |
337 | .get_parent = cs2000_get_parent, | |
338 | .recalc_rate = cs2000_recalc_rate, | |
339 | .round_rate = cs2000_round_rate, | |
340 | .set_rate = cs2000_set_rate, | |
341 | .prepare = cs2000_enable, | |
342 | .unprepare = cs2000_disable, | |
343 | }; | |
344 | ||
345 | static int cs2000_clk_get(struct cs2000_priv *priv) | |
346 | { | |
347 | struct i2c_client *client = priv_to_client(priv); | |
348 | struct device *dev = &client->dev; | |
349 | struct clk *clk_in, *ref_clk; | |
350 | ||
351 | clk_in = devm_clk_get(dev, "clk_in"); | |
352 | /* not yet provided */ | |
353 | if (IS_ERR(clk_in)) | |
354 | return -EPROBE_DEFER; | |
355 | ||
356 | ref_clk = devm_clk_get(dev, "ref_clk"); | |
357 | /* not yet provided */ | |
358 | if (IS_ERR(ref_clk)) | |
359 | return -EPROBE_DEFER; | |
360 | ||
361 | priv->clk_in = clk_in; | |
362 | priv->ref_clk = ref_clk; | |
363 | ||
364 | return 0; | |
365 | } | |
366 | ||
367 | static int cs2000_clk_register(struct cs2000_priv *priv) | |
368 | { | |
369 | struct device *dev = priv_to_dev(priv); | |
370 | struct device_node *np = dev->of_node; | |
371 | struct clk_init_data init; | |
372 | const char *name = np->name; | |
64dfbe24 KM |
373 | static const char *parent_names[CLK_MAX]; |
374 | int ch = 0; /* it uses ch0 only at this point */ | |
375 | int rate; | |
376 | int ret; | |
377 | ||
378 | of_property_read_string(np, "clock-output-names", &name); | |
379 | ||
380 | /* | |
381 | * set default rate as 1/1. | |
382 | * otherwise .set_rate which setup ratio | |
383 | * is never called if user requests 1/1 rate | |
384 | */ | |
385 | rate = clk_get_rate(priv->ref_clk); | |
386 | ret = __cs2000_set_rate(priv, ch, rate, rate); | |
387 | if (ret < 0) | |
388 | return ret; | |
389 | ||
390 | parent_names[CLK_IN] = __clk_get_name(priv->clk_in); | |
391 | parent_names[REF_CLK] = __clk_get_name(priv->ref_clk); | |
392 | ||
393 | init.name = name; | |
394 | init.ops = &cs2000_ops; | |
395 | init.flags = CLK_SET_RATE_GATE; | |
396 | init.parent_names = parent_names; | |
397 | init.num_parents = ARRAY_SIZE(parent_names); | |
398 | ||
399 | priv->hw.init = &init; | |
400 | ||
2ceb3c7a SB |
401 | ret = clk_hw_register(dev, &priv->hw); |
402 | if (ret) | |
403 | return ret; | |
64dfbe24 | 404 | |
2ceb3c7a | 405 | ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw); |
64dfbe24 | 406 | if (ret < 0) { |
2ceb3c7a | 407 | clk_hw_unregister(&priv->hw); |
64dfbe24 KM |
408 | return ret; |
409 | } | |
410 | ||
64dfbe24 KM |
411 | return 0; |
412 | } | |
413 | ||
414 | static int cs2000_version_print(struct cs2000_priv *priv) | |
415 | { | |
416 | struct i2c_client *client = priv_to_client(priv); | |
417 | struct device *dev = &client->dev; | |
418 | s32 val; | |
419 | const char *revision; | |
420 | ||
421 | val = cs2000_read(priv, DEVICE_ID); | |
422 | if (val < 0) | |
423 | return val; | |
424 | ||
425 | /* CS2000 should be 0x0 */ | |
426 | if (val >> 3) | |
427 | return -EIO; | |
428 | ||
429 | switch (val & REVISION_MASK) { | |
430 | case REVISION_B2_B3: | |
431 | revision = "B2 / B3"; | |
432 | break; | |
433 | case REVISION_C1: | |
434 | revision = "C1"; | |
435 | break; | |
436 | default: | |
437 | return -EIO; | |
438 | } | |
439 | ||
440 | dev_info(dev, "revision - %s\n", revision); | |
441 | ||
442 | return 0; | |
443 | } | |
444 | ||
445 | static int cs2000_remove(struct i2c_client *client) | |
446 | { | |
447 | struct cs2000_priv *priv = i2c_get_clientdata(client); | |
448 | struct device *dev = &client->dev; | |
449 | struct device_node *np = dev->of_node; | |
450 | ||
451 | of_clk_del_provider(np); | |
452 | ||
2ceb3c7a | 453 | clk_hw_unregister(&priv->hw); |
64dfbe24 KM |
454 | |
455 | return 0; | |
456 | } | |
457 | ||
458 | static int cs2000_probe(struct i2c_client *client, | |
459 | const struct i2c_device_id *id) | |
460 | { | |
461 | struct cs2000_priv *priv; | |
462 | struct device *dev = &client->dev; | |
463 | int ret; | |
464 | ||
465 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | |
466 | if (!priv) | |
467 | return -ENOMEM; | |
468 | ||
469 | priv->client = client; | |
470 | i2c_set_clientdata(client, priv); | |
471 | ||
472 | ret = cs2000_clk_get(priv); | |
473 | if (ret < 0) | |
474 | return ret; | |
475 | ||
476 | ret = cs2000_clk_register(priv); | |
477 | if (ret < 0) | |
478 | return ret; | |
479 | ||
480 | ret = cs2000_version_print(priv); | |
481 | if (ret < 0) | |
482 | goto probe_err; | |
483 | ||
484 | return 0; | |
485 | ||
486 | probe_err: | |
487 | cs2000_remove(client); | |
488 | ||
489 | return ret; | |
490 | } | |
491 | ||
492 | static struct i2c_driver cs2000_driver = { | |
493 | .driver = { | |
494 | .name = "cs2000-cp", | |
495 | .of_match_table = cs2000_of_match, | |
496 | }, | |
497 | .probe = cs2000_probe, | |
498 | .remove = cs2000_remove, | |
499 | .id_table = cs2000_id, | |
500 | }; | |
501 | ||
502 | module_i2c_driver(cs2000_driver); | |
503 | ||
504 | MODULE_DESCRIPTION("CS2000-CP driver"); | |
505 | MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>"); | |
506 | MODULE_LICENSE("GPL v2"); |