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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; | |
62 | struct clk *clk_out; | |
63 | }; | |
64 | ||
65 | static const struct of_device_id cs2000_of_match[] = { | |
66 | { .compatible = "cirrus,cs2000-cp", }, | |
67 | {}, | |
68 | }; | |
69 | MODULE_DEVICE_TABLE(of, cs2000_of_match); | |
70 | ||
71 | static const struct i2c_device_id cs2000_id[] = { | |
72 | { "cs2000-cp", }, | |
73 | {} | |
74 | }; | |
75 | MODULE_DEVICE_TABLE(i2c, cs2000_id); | |
76 | ||
77 | #define cs2000_read(priv, addr) \ | |
78 | i2c_smbus_read_byte_data(priv_to_client(priv), addr) | |
79 | #define cs2000_write(priv, addr, val) \ | |
80 | i2c_smbus_write_byte_data(priv_to_client(priv), addr, val) | |
81 | ||
82 | static int cs2000_bset(struct cs2000_priv *priv, u8 addr, u8 mask, u8 val) | |
83 | { | |
84 | s32 data; | |
85 | ||
86 | data = cs2000_read(priv, addr); | |
87 | if (data < 0) | |
88 | return data; | |
89 | ||
90 | data &= ~mask; | |
91 | data |= (val & mask); | |
92 | ||
93 | return cs2000_write(priv, addr, data); | |
94 | } | |
95 | ||
96 | static int cs2000_enable_dev_config(struct cs2000_priv *priv, bool enable) | |
97 | { | |
98 | int ret; | |
99 | ||
100 | ret = cs2000_bset(priv, DEVICE_CFG1, ENDEV1, | |
101 | enable ? ENDEV1 : 0); | |
102 | if (ret < 0) | |
103 | return ret; | |
104 | ||
105 | ret = cs2000_bset(priv, GLOBAL_CFG, ENDEV2, | |
106 | enable ? ENDEV2 : 0); | |
107 | if (ret < 0) | |
108 | return ret; | |
109 | ||
110 | return 0; | |
111 | } | |
112 | ||
113 | static int cs2000_clk_in_bound_rate(struct cs2000_priv *priv, | |
114 | u32 rate_in) | |
115 | { | |
116 | u32 val; | |
117 | ||
118 | if (rate_in >= 32000000 && rate_in < 56000000) | |
119 | val = 0x0; | |
120 | else if (rate_in >= 16000000 && rate_in < 28000000) | |
121 | val = 0x1; | |
122 | else if (rate_in >= 8000000 && rate_in < 14000000) | |
123 | val = 0x2; | |
124 | else | |
125 | return -EINVAL; | |
126 | ||
127 | return cs2000_bset(priv, FUNC_CFG1, 0x3 << 3, val << 3); | |
128 | } | |
129 | ||
130 | static int cs2000_wait_pll_lock(struct cs2000_priv *priv) | |
131 | { | |
132 | struct device *dev = priv_to_dev(priv); | |
133 | s32 val; | |
134 | unsigned int i; | |
135 | ||
136 | for (i = 0; i < 256; i++) { | |
137 | val = cs2000_read(priv, DEVICE_CTRL); | |
138 | if (val < 0) | |
139 | return val; | |
140 | if (!(val & PLL_UNLOCK)) | |
141 | return 0; | |
142 | udelay(1); | |
143 | } | |
144 | ||
145 | dev_err(dev, "pll lock failed\n"); | |
146 | ||
147 | return -ETIMEDOUT; | |
148 | } | |
149 | ||
150 | static int cs2000_clk_out_enable(struct cs2000_priv *priv, bool enable) | |
151 | { | |
152 | /* enable both AUX_OUT, CLK_OUT */ | |
153 | return cs2000_write(priv, DEVICE_CTRL, enable ? 0 : 0x3); | |
154 | } | |
155 | ||
156 | static u32 cs2000_rate_to_ratio(u32 rate_in, u32 rate_out) | |
157 | { | |
158 | u64 ratio; | |
159 | ||
160 | /* | |
161 | * ratio = rate_out / rate_in * 2^20 | |
162 | * | |
163 | * To avoid over flow, rate_out is u64. | |
164 | * The result should be u32. | |
165 | */ | |
166 | ratio = (u64)rate_out << 20; | |
167 | do_div(ratio, rate_in); | |
168 | ||
169 | return ratio; | |
170 | } | |
171 | ||
172 | static unsigned long cs2000_ratio_to_rate(u32 ratio, u32 rate_in) | |
173 | { | |
174 | u64 rate_out; | |
175 | ||
176 | /* | |
177 | * ratio = rate_out / rate_in * 2^20 | |
178 | * | |
179 | * To avoid over flow, rate_out is u64. | |
180 | * The result should be u32 or unsigned long. | |
181 | */ | |
182 | ||
183 | rate_out = (u64)ratio * rate_in; | |
184 | return rate_out >> 20; | |
185 | } | |
186 | ||
187 | static int cs2000_ratio_set(struct cs2000_priv *priv, | |
188 | int ch, u32 rate_in, u32 rate_out) | |
189 | { | |
190 | u32 val; | |
191 | unsigned int i; | |
192 | int ret; | |
193 | ||
194 | if (CH_SIZE_ERR(ch)) | |
195 | return -EINVAL; | |
196 | ||
197 | val = cs2000_rate_to_ratio(rate_in, rate_out); | |
198 | for (i = 0; i < RATIO_REG_SIZE; i++) { | |
199 | ret = cs2000_write(priv, | |
200 | Ratio_Add(ch, i), | |
201 | Ratio_Val(val, i)); | |
202 | if (ret < 0) | |
203 | return ret; | |
204 | } | |
205 | ||
206 | return 0; | |
207 | } | |
208 | ||
209 | static u32 cs2000_ratio_get(struct cs2000_priv *priv, int ch) | |
210 | { | |
211 | s32 tmp; | |
212 | u32 val; | |
213 | unsigned int i; | |
214 | ||
215 | val = 0; | |
216 | for (i = 0; i < RATIO_REG_SIZE; i++) { | |
217 | tmp = cs2000_read(priv, Ratio_Add(ch, i)); | |
218 | if (tmp < 0) | |
219 | return 0; | |
220 | ||
221 | val |= Val_Ratio(tmp, i); | |
222 | } | |
223 | ||
224 | return val; | |
225 | } | |
226 | ||
227 | static int cs2000_ratio_select(struct cs2000_priv *priv, int ch) | |
228 | { | |
229 | int ret; | |
230 | ||
231 | if (CH_SIZE_ERR(ch)) | |
232 | return -EINVAL; | |
233 | ||
234 | /* | |
235 | * FIXME | |
236 | * | |
237 | * this driver supports static ratio mode only at this point. | |
238 | */ | |
239 | ret = cs2000_bset(priv, DEVICE_CFG1, RSEL_MASK, RSEL(ch)); | |
240 | if (ret < 0) | |
241 | return ret; | |
242 | ||
243 | ret = cs2000_write(priv, DEVICE_CFG2, 0x0); | |
244 | if (ret < 0) | |
245 | return ret; | |
246 | ||
247 | return 0; | |
248 | } | |
249 | ||
250 | static unsigned long cs2000_recalc_rate(struct clk_hw *hw, | |
251 | unsigned long parent_rate) | |
252 | { | |
253 | struct cs2000_priv *priv = hw_to_priv(hw); | |
254 | int ch = 0; /* it uses ch0 only at this point */ | |
255 | u32 ratio; | |
256 | ||
257 | ratio = cs2000_ratio_get(priv, ch); | |
258 | ||
259 | return cs2000_ratio_to_rate(ratio, parent_rate); | |
260 | } | |
261 | ||
262 | static long cs2000_round_rate(struct clk_hw *hw, unsigned long rate, | |
263 | unsigned long *parent_rate) | |
264 | { | |
265 | u32 ratio; | |
266 | ||
267 | ratio = cs2000_rate_to_ratio(*parent_rate, rate); | |
268 | ||
269 | return cs2000_ratio_to_rate(ratio, *parent_rate); | |
270 | } | |
271 | ||
272 | static int __cs2000_set_rate(struct cs2000_priv *priv, int ch, | |
273 | unsigned long rate, unsigned long parent_rate) | |
274 | ||
275 | { | |
276 | int ret; | |
277 | ||
278 | ret = cs2000_clk_in_bound_rate(priv, parent_rate); | |
279 | if (ret < 0) | |
280 | return ret; | |
281 | ||
282 | ret = cs2000_ratio_set(priv, ch, parent_rate, rate); | |
283 | if (ret < 0) | |
284 | return ret; | |
285 | ||
286 | ret = cs2000_ratio_select(priv, ch); | |
287 | if (ret < 0) | |
288 | return ret; | |
289 | ||
290 | return 0; | |
291 | } | |
292 | ||
293 | static int cs2000_set_rate(struct clk_hw *hw, | |
294 | unsigned long rate, unsigned long parent_rate) | |
295 | { | |
296 | struct cs2000_priv *priv = hw_to_priv(hw); | |
297 | int ch = 0; /* it uses ch0 only at this point */ | |
298 | ||
299 | return __cs2000_set_rate(priv, ch, rate, parent_rate); | |
300 | } | |
301 | ||
302 | static int cs2000_enable(struct clk_hw *hw) | |
303 | { | |
304 | struct cs2000_priv *priv = hw_to_priv(hw); | |
305 | int ret; | |
306 | ||
307 | ret = cs2000_enable_dev_config(priv, true); | |
308 | if (ret < 0) | |
309 | return ret; | |
310 | ||
311 | ret = cs2000_clk_out_enable(priv, true); | |
312 | if (ret < 0) | |
313 | return ret; | |
314 | ||
315 | ret = cs2000_wait_pll_lock(priv); | |
316 | if (ret < 0) | |
317 | return ret; | |
318 | ||
319 | return ret; | |
320 | } | |
321 | ||
322 | static void cs2000_disable(struct clk_hw *hw) | |
323 | { | |
324 | struct cs2000_priv *priv = hw_to_priv(hw); | |
325 | ||
326 | cs2000_enable_dev_config(priv, false); | |
327 | ||
328 | cs2000_clk_out_enable(priv, false); | |
329 | } | |
330 | ||
331 | static u8 cs2000_get_parent(struct clk_hw *hw) | |
332 | { | |
333 | /* always return REF_CLK */ | |
334 | return REF_CLK; | |
335 | } | |
336 | ||
337 | static const struct clk_ops cs2000_ops = { | |
338 | .get_parent = cs2000_get_parent, | |
339 | .recalc_rate = cs2000_recalc_rate, | |
340 | .round_rate = cs2000_round_rate, | |
341 | .set_rate = cs2000_set_rate, | |
342 | .prepare = cs2000_enable, | |
343 | .unprepare = cs2000_disable, | |
344 | }; | |
345 | ||
346 | static int cs2000_clk_get(struct cs2000_priv *priv) | |
347 | { | |
348 | struct i2c_client *client = priv_to_client(priv); | |
349 | struct device *dev = &client->dev; | |
350 | struct clk *clk_in, *ref_clk; | |
351 | ||
352 | clk_in = devm_clk_get(dev, "clk_in"); | |
353 | /* not yet provided */ | |
354 | if (IS_ERR(clk_in)) | |
355 | return -EPROBE_DEFER; | |
356 | ||
357 | ref_clk = devm_clk_get(dev, "ref_clk"); | |
358 | /* not yet provided */ | |
359 | if (IS_ERR(ref_clk)) | |
360 | return -EPROBE_DEFER; | |
361 | ||
362 | priv->clk_in = clk_in; | |
363 | priv->ref_clk = ref_clk; | |
364 | ||
365 | return 0; | |
366 | } | |
367 | ||
368 | static int cs2000_clk_register(struct cs2000_priv *priv) | |
369 | { | |
370 | struct device *dev = priv_to_dev(priv); | |
371 | struct device_node *np = dev->of_node; | |
372 | struct clk_init_data init; | |
373 | const char *name = np->name; | |
374 | struct clk *clk; | |
375 | static const char *parent_names[CLK_MAX]; | |
376 | int ch = 0; /* it uses ch0 only at this point */ | |
377 | int rate; | |
378 | int ret; | |
379 | ||
380 | of_property_read_string(np, "clock-output-names", &name); | |
381 | ||
382 | /* | |
383 | * set default rate as 1/1. | |
384 | * otherwise .set_rate which setup ratio | |
385 | * is never called if user requests 1/1 rate | |
386 | */ | |
387 | rate = clk_get_rate(priv->ref_clk); | |
388 | ret = __cs2000_set_rate(priv, ch, rate, rate); | |
389 | if (ret < 0) | |
390 | return ret; | |
391 | ||
392 | parent_names[CLK_IN] = __clk_get_name(priv->clk_in); | |
393 | parent_names[REF_CLK] = __clk_get_name(priv->ref_clk); | |
394 | ||
395 | init.name = name; | |
396 | init.ops = &cs2000_ops; | |
397 | init.flags = CLK_SET_RATE_GATE; | |
398 | init.parent_names = parent_names; | |
399 | init.num_parents = ARRAY_SIZE(parent_names); | |
400 | ||
401 | priv->hw.init = &init; | |
402 | ||
403 | clk = clk_register(dev, &priv->hw); | |
404 | if (IS_ERR(clk)) | |
405 | return PTR_ERR(clk); | |
406 | ||
407 | ret = of_clk_add_provider(np, of_clk_src_simple_get, clk); | |
408 | if (ret < 0) { | |
409 | clk_unregister(clk); | |
410 | return ret; | |
411 | } | |
412 | ||
413 | priv->clk_out = clk; | |
414 | ||
415 | return 0; | |
416 | } | |
417 | ||
418 | static int cs2000_version_print(struct cs2000_priv *priv) | |
419 | { | |
420 | struct i2c_client *client = priv_to_client(priv); | |
421 | struct device *dev = &client->dev; | |
422 | s32 val; | |
423 | const char *revision; | |
424 | ||
425 | val = cs2000_read(priv, DEVICE_ID); | |
426 | if (val < 0) | |
427 | return val; | |
428 | ||
429 | /* CS2000 should be 0x0 */ | |
430 | if (val >> 3) | |
431 | return -EIO; | |
432 | ||
433 | switch (val & REVISION_MASK) { | |
434 | case REVISION_B2_B3: | |
435 | revision = "B2 / B3"; | |
436 | break; | |
437 | case REVISION_C1: | |
438 | revision = "C1"; | |
439 | break; | |
440 | default: | |
441 | return -EIO; | |
442 | } | |
443 | ||
444 | dev_info(dev, "revision - %s\n", revision); | |
445 | ||
446 | return 0; | |
447 | } | |
448 | ||
449 | static int cs2000_remove(struct i2c_client *client) | |
450 | { | |
451 | struct cs2000_priv *priv = i2c_get_clientdata(client); | |
452 | struct device *dev = &client->dev; | |
453 | struct device_node *np = dev->of_node; | |
454 | ||
455 | of_clk_del_provider(np); | |
456 | ||
457 | clk_unregister(priv->clk_out); | |
458 | ||
459 | return 0; | |
460 | } | |
461 | ||
462 | static int cs2000_probe(struct i2c_client *client, | |
463 | const struct i2c_device_id *id) | |
464 | { | |
465 | struct cs2000_priv *priv; | |
466 | struct device *dev = &client->dev; | |
467 | int ret; | |
468 | ||
469 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | |
470 | if (!priv) | |
471 | return -ENOMEM; | |
472 | ||
473 | priv->client = client; | |
474 | i2c_set_clientdata(client, priv); | |
475 | ||
476 | ret = cs2000_clk_get(priv); | |
477 | if (ret < 0) | |
478 | return ret; | |
479 | ||
480 | ret = cs2000_clk_register(priv); | |
481 | if (ret < 0) | |
482 | return ret; | |
483 | ||
484 | ret = cs2000_version_print(priv); | |
485 | if (ret < 0) | |
486 | goto probe_err; | |
487 | ||
488 | return 0; | |
489 | ||
490 | probe_err: | |
491 | cs2000_remove(client); | |
492 | ||
493 | return ret; | |
494 | } | |
495 | ||
496 | static struct i2c_driver cs2000_driver = { | |
497 | .driver = { | |
498 | .name = "cs2000-cp", | |
499 | .of_match_table = cs2000_of_match, | |
500 | }, | |
501 | .probe = cs2000_probe, | |
502 | .remove = cs2000_remove, | |
503 | .id_table = cs2000_id, | |
504 | }; | |
505 | ||
506 | module_i2c_driver(cs2000_driver); | |
507 | ||
508 | MODULE_DESCRIPTION("CS2000-CP driver"); | |
509 | MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>"); | |
510 | MODULE_LICENSE("GPL v2"); |