xref: /openbmc/linux/drivers/clk/st/clkgen-fsyn.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 STMicroelectronics R&D Ltd
4  */
5 
6 /*
7  * Authors:
8  * Stephen Gallimore <stephen.gallimore@st.com>,
9  * Pankaj Dev <pankaj.dev@st.com>.
10  */
11 
12 #include <linux/slab.h>
13 #include <linux/of_address.h>
14 #include <linux/clk.h>
15 #include <linux/clk-provider.h>
16 
17 #include "clkgen.h"
18 
19 /*
20  * Maximum input clock to the PLL before we divide it down by 2
21  * although in reality in actual systems this has never been seen to
22  * be used.
23  */
24 #define QUADFS_NDIV_THRESHOLD 30000000
25 
26 #define PLL_BW_GOODREF   (0L)
27 #define PLL_BW_VBADREF   (1L)
28 #define PLL_BW_BADREF    (2L)
29 #define PLL_BW_VGOODREF  (3L)
30 
31 #define QUADFS_MAX_CHAN 4
32 
33 struct stm_fs {
34 	unsigned long ndiv;
35 	unsigned long mdiv;
36 	unsigned long pe;
37 	unsigned long sdiv;
38 	unsigned long nsdiv;
39 };
40 
41 struct clkgen_quadfs_data {
42 	bool reset_present;
43 	bool bwfilter_present;
44 	bool lockstatus_present;
45 	bool powerup_polarity;
46 	bool standby_polarity;
47 	bool nsdiv_present;
48 	bool nrst_present;
49 	struct clkgen_field ndiv;
50 	struct clkgen_field ref_bw;
51 	struct clkgen_field nreset;
52 	struct clkgen_field npda;
53 	struct clkgen_field lock_status;
54 
55 	struct clkgen_field nrst[QUADFS_MAX_CHAN];
56 	struct clkgen_field nsb[QUADFS_MAX_CHAN];
57 	struct clkgen_field en[QUADFS_MAX_CHAN];
58 	struct clkgen_field mdiv[QUADFS_MAX_CHAN];
59 	struct clkgen_field pe[QUADFS_MAX_CHAN];
60 	struct clkgen_field sdiv[QUADFS_MAX_CHAN];
61 	struct clkgen_field nsdiv[QUADFS_MAX_CHAN];
62 
63 	const struct clk_ops *pll_ops;
64 	int  (*get_params)(unsigned long, unsigned long, struct stm_fs *);
65 	int  (*get_rate)(unsigned long , const struct stm_fs *,
66 			unsigned long *);
67 };
68 
69 struct clkgen_clk_out {
70 	const char *name;
71 	unsigned long flags;
72 };
73 
74 struct clkgen_quadfs_data_clks {
75 	struct clkgen_quadfs_data *data;
76 	const struct clkgen_clk_out *outputs;
77 };
78 
79 static const struct clk_ops st_quadfs_pll_c32_ops;
80 
81 static int clk_fs660c32_dig_get_params(unsigned long input,
82 		unsigned long output, struct stm_fs *fs);
83 static int clk_fs660c32_dig_get_rate(unsigned long, const struct stm_fs *,
84 		unsigned long *);
85 
86 static const struct clkgen_quadfs_data st_fs660c32_C = {
87 	.nrst_present = true,
88 	.nrst	= { CLKGEN_FIELD(0x2f0, 0x1, 0),
89 		    CLKGEN_FIELD(0x2f0, 0x1, 1),
90 		    CLKGEN_FIELD(0x2f0, 0x1, 2),
91 		    CLKGEN_FIELD(0x2f0, 0x1, 3) },
92 	.npda	= CLKGEN_FIELD(0x2f0, 0x1, 12),
93 	.nsb	= { CLKGEN_FIELD(0x2f0, 0x1, 8),
94 		    CLKGEN_FIELD(0x2f0, 0x1, 9),
95 		    CLKGEN_FIELD(0x2f0, 0x1, 10),
96 		    CLKGEN_FIELD(0x2f0, 0x1, 11) },
97 	.nsdiv_present = true,
98 	.nsdiv	= { CLKGEN_FIELD(0x304, 0x1, 24),
99 		    CLKGEN_FIELD(0x308, 0x1, 24),
100 		    CLKGEN_FIELD(0x30c, 0x1, 24),
101 		    CLKGEN_FIELD(0x310, 0x1, 24) },
102 	.mdiv	= { CLKGEN_FIELD(0x304, 0x1f, 15),
103 		    CLKGEN_FIELD(0x308, 0x1f, 15),
104 		    CLKGEN_FIELD(0x30c, 0x1f, 15),
105 		    CLKGEN_FIELD(0x310, 0x1f, 15) },
106 	.en	= { CLKGEN_FIELD(0x2fc, 0x1, 0),
107 		    CLKGEN_FIELD(0x2fc, 0x1, 1),
108 		    CLKGEN_FIELD(0x2fc, 0x1, 2),
109 		    CLKGEN_FIELD(0x2fc, 0x1, 3) },
110 	.ndiv	= CLKGEN_FIELD(0x2f4, 0x7, 16),
111 	.pe	= { CLKGEN_FIELD(0x304, 0x7fff, 0),
112 		    CLKGEN_FIELD(0x308, 0x7fff, 0),
113 		    CLKGEN_FIELD(0x30c, 0x7fff, 0),
114 		    CLKGEN_FIELD(0x310, 0x7fff, 0) },
115 	.sdiv	= { CLKGEN_FIELD(0x304, 0xf, 20),
116 		    CLKGEN_FIELD(0x308, 0xf, 20),
117 		    CLKGEN_FIELD(0x30c, 0xf, 20),
118 		    CLKGEN_FIELD(0x310, 0xf, 20) },
119 	.lockstatus_present = true,
120 	.lock_status = CLKGEN_FIELD(0x2f0, 0x1, 24),
121 	.powerup_polarity = 1,
122 	.standby_polarity = 1,
123 	.pll_ops	= &st_quadfs_pll_c32_ops,
124 	.get_params	= clk_fs660c32_dig_get_params,
125 	.get_rate	= clk_fs660c32_dig_get_rate,
126 };
127 
128 static const struct clkgen_clk_out st_fs660c32_C_clks[] = {
129 	{ .name = "clk-s-c0-fs0-ch0",	},
130 	{ .name = "clk-s-c0-fs0-ch1",	},
131 	{ .name = "clk-s-c0-fs0-ch2",	},
132 	{ .name = "clk-s-c0-fs0-ch3",	},
133 };
134 
135 static const struct clkgen_quadfs_data_clks st_fs660c32_C_data = {
136 	.data	= (struct clkgen_quadfs_data *)&st_fs660c32_C,
137 	.outputs	= st_fs660c32_C_clks,
138 };
139 
140 static const struct clkgen_quadfs_data st_fs660c32_D = {
141 	.nrst_present = true,
142 	.nrst	= { CLKGEN_FIELD(0x2a0, 0x1, 0),
143 		    CLKGEN_FIELD(0x2a0, 0x1, 1),
144 		    CLKGEN_FIELD(0x2a0, 0x1, 2),
145 		    CLKGEN_FIELD(0x2a0, 0x1, 3) },
146 	.ndiv	= CLKGEN_FIELD(0x2a4, 0x7, 16),
147 	.pe	= { CLKGEN_FIELD(0x2b4, 0x7fff, 0),
148 		    CLKGEN_FIELD(0x2b8, 0x7fff, 0),
149 		    CLKGEN_FIELD(0x2bc, 0x7fff, 0),
150 		    CLKGEN_FIELD(0x2c0, 0x7fff, 0) },
151 	.sdiv	= { CLKGEN_FIELD(0x2b4, 0xf, 20),
152 		    CLKGEN_FIELD(0x2b8, 0xf, 20),
153 		    CLKGEN_FIELD(0x2bc, 0xf, 20),
154 		    CLKGEN_FIELD(0x2c0, 0xf, 20) },
155 	.npda	= CLKGEN_FIELD(0x2a0, 0x1, 12),
156 	.nsb	= { CLKGEN_FIELD(0x2a0, 0x1, 8),
157 		    CLKGEN_FIELD(0x2a0, 0x1, 9),
158 		    CLKGEN_FIELD(0x2a0, 0x1, 10),
159 		    CLKGEN_FIELD(0x2a0, 0x1, 11) },
160 	.nsdiv_present = true,
161 	.nsdiv	= { CLKGEN_FIELD(0x2b4, 0x1, 24),
162 		    CLKGEN_FIELD(0x2b8, 0x1, 24),
163 		    CLKGEN_FIELD(0x2bc, 0x1, 24),
164 		    CLKGEN_FIELD(0x2c0, 0x1, 24) },
165 	.mdiv	= { CLKGEN_FIELD(0x2b4, 0x1f, 15),
166 		    CLKGEN_FIELD(0x2b8, 0x1f, 15),
167 		    CLKGEN_FIELD(0x2bc, 0x1f, 15),
168 		    CLKGEN_FIELD(0x2c0, 0x1f, 15) },
169 	.en	= { CLKGEN_FIELD(0x2ac, 0x1, 0),
170 		    CLKGEN_FIELD(0x2ac, 0x1, 1),
171 		    CLKGEN_FIELD(0x2ac, 0x1, 2),
172 		    CLKGEN_FIELD(0x2ac, 0x1, 3) },
173 	.lockstatus_present = true,
174 	.lock_status = CLKGEN_FIELD(0x2A0, 0x1, 24),
175 	.powerup_polarity = 1,
176 	.standby_polarity = 1,
177 	.pll_ops	= &st_quadfs_pll_c32_ops,
178 	.get_params	= clk_fs660c32_dig_get_params,
179 	.get_rate	= clk_fs660c32_dig_get_rate,};
180 
181 static const struct clkgen_quadfs_data_clks st_fs660c32_D_data = {
182 	.data	= (struct clkgen_quadfs_data *)&st_fs660c32_D,
183 };
184 
185 static const struct clkgen_clk_out st_fs660c32_D0_clks[] = {
186 	{ .name = "clk-s-d0-fs0-ch0",	},
187 	{ .name = "clk-s-d0-fs0-ch1",	},
188 	{ .name = "clk-s-d0-fs0-ch2",	},
189 	{ .name = "clk-s-d0-fs0-ch3",	},
190 };
191 
192 static const struct clkgen_quadfs_data_clks st_fs660c32_D0_data = {
193 	.data	= (struct clkgen_quadfs_data *)&st_fs660c32_D,
194 	.outputs	= st_fs660c32_D0_clks,
195 };
196 
197 static const struct clkgen_clk_out st_fs660c32_D2_clks[] = {
198 	{ .name = "clk-s-d2-fs0-ch0",	},
199 	{ .name = "clk-s-d2-fs0-ch1",	},
200 	{ .name = "clk-s-d2-fs0-ch2",	},
201 	{ .name = "clk-s-d2-fs0-ch3",	},
202 };
203 
204 static const struct clkgen_quadfs_data_clks st_fs660c32_D2_data = {
205 	.data	= (struct clkgen_quadfs_data *)&st_fs660c32_D,
206 	.outputs	= st_fs660c32_D2_clks,
207 };
208 
209 static const struct clkgen_clk_out st_fs660c32_D3_clks[] = {
210 	{ .name = "clk-s-d3-fs0-ch0",	},
211 	{ .name = "clk-s-d3-fs0-ch1",	},
212 	{ .name = "clk-s-d3-fs0-ch2",	},
213 	{ .name = "clk-s-d3-fs0-ch3",	},
214 };
215 
216 static const struct clkgen_quadfs_data_clks st_fs660c32_D3_data = {
217 	.data	= (struct clkgen_quadfs_data *)&st_fs660c32_D,
218 	.outputs	= st_fs660c32_D3_clks,
219 };
220 
221 /**
222  * DOC: A Frequency Synthesizer that multiples its input clock by a fixed factor
223  *
224  * Traits of this clock:
225  * prepare - clk_(un)prepare only ensures parent is (un)prepared
226  * enable - clk_enable and clk_disable are functional & control the Fsyn
227  * rate - inherits rate from parent. set_rate/round_rate/recalc_rate
228  * parent - fixed parent.  No clk_set_parent support
229  */
230 
231 /**
232  * struct st_clk_quadfs_pll - A pll which outputs a fixed multiplier of
233  *                                  its parent clock, found inside a type of
234  *                                  ST quad channel frequency synthesizer block
235  *
236  * @hw: handle between common and hardware-specific interfaces.
237  * @regs_base: base address of the configuration registers.
238  * @lock: spinlock.
239  * @data: local driver data
240  * @ndiv: regmap field for the ndiv control.
241  */
242 struct st_clk_quadfs_pll {
243 	struct clk_hw	hw;
244 	void __iomem	*regs_base;
245 	spinlock_t	*lock;
246 	struct clkgen_quadfs_data *data;
247 	u32 ndiv;
248 };
249 
250 #define to_quadfs_pll(_hw) container_of(_hw, struct st_clk_quadfs_pll, hw)
251 
252 static int quadfs_pll_enable(struct clk_hw *hw)
253 {
254 	struct st_clk_quadfs_pll *pll = to_quadfs_pll(hw);
255 	unsigned long flags = 0, timeout = jiffies + msecs_to_jiffies(10);
256 
257 	if (pll->lock)
258 		spin_lock_irqsave(pll->lock, flags);
259 
260 	/*
261 	 * Bring block out of reset if we have reset control.
262 	 */
263 	if (pll->data->reset_present)
264 		CLKGEN_WRITE(pll, nreset, 1);
265 
266 	/*
267 	 * Use a fixed input clock noise bandwidth filter for the moment
268 	 */
269 	if (pll->data->bwfilter_present)
270 		CLKGEN_WRITE(pll, ref_bw, PLL_BW_GOODREF);
271 
272 
273 	CLKGEN_WRITE(pll, ndiv, pll->ndiv);
274 
275 	/*
276 	 * Power up the PLL
277 	 */
278 	CLKGEN_WRITE(pll, npda, !pll->data->powerup_polarity);
279 
280 	if (pll->lock)
281 		spin_unlock_irqrestore(pll->lock, flags);
282 
283 	if (pll->data->lockstatus_present)
284 		while (!CLKGEN_READ(pll, lock_status)) {
285 			if (time_after(jiffies, timeout))
286 				return -ETIMEDOUT;
287 			cpu_relax();
288 		}
289 
290 	return 0;
291 }
292 
293 static void quadfs_pll_disable(struct clk_hw *hw)
294 {
295 	struct st_clk_quadfs_pll *pll = to_quadfs_pll(hw);
296 	unsigned long flags = 0;
297 
298 	if (pll->lock)
299 		spin_lock_irqsave(pll->lock, flags);
300 
301 	/*
302 	 * Powerdown the PLL and then put block into soft reset if we have
303 	 * reset control.
304 	 */
305 	CLKGEN_WRITE(pll, npda, pll->data->powerup_polarity);
306 
307 	if (pll->data->reset_present)
308 		CLKGEN_WRITE(pll, nreset, 0);
309 
310 	if (pll->lock)
311 		spin_unlock_irqrestore(pll->lock, flags);
312 }
313 
314 static int quadfs_pll_is_enabled(struct clk_hw *hw)
315 {
316 	struct st_clk_quadfs_pll *pll = to_quadfs_pll(hw);
317 	u32 npda = CLKGEN_READ(pll, npda);
318 
319 	return pll->data->powerup_polarity ? !npda : !!npda;
320 }
321 
322 static int clk_fs660c32_vco_get_rate(unsigned long input, struct stm_fs *fs,
323 			   unsigned long *rate)
324 {
325 	unsigned long nd = fs->ndiv + 16; /* ndiv value */
326 
327 	*rate = input * nd;
328 
329 	return 0;
330 }
331 
332 static unsigned long quadfs_pll_fs660c32_recalc_rate(struct clk_hw *hw,
333 					unsigned long parent_rate)
334 {
335 	struct st_clk_quadfs_pll *pll = to_quadfs_pll(hw);
336 	unsigned long rate = 0;
337 	struct stm_fs params;
338 
339 	params.ndiv = CLKGEN_READ(pll, ndiv);
340 	if (clk_fs660c32_vco_get_rate(parent_rate, &params, &rate))
341 		pr_err("%s:%s error calculating rate\n",
342 		       clk_hw_get_name(hw), __func__);
343 
344 	pll->ndiv = params.ndiv;
345 
346 	return rate;
347 }
348 
349 static int clk_fs660c32_vco_get_params(unsigned long input,
350 				unsigned long output, struct stm_fs *fs)
351 {
352 /* Formula
353    VCO frequency = (fin x ndiv) / pdiv
354    ndiv = VCOfreq * pdiv / fin
355    */
356 	unsigned long pdiv = 1, n;
357 
358 	/* Output clock range: 384Mhz to 660Mhz */
359 	if (output < 384000000 || output > 660000000)
360 		return -EINVAL;
361 
362 	if (input > 40000000)
363 		/* This means that PDIV would be 2 instead of 1.
364 		   Not supported today. */
365 		return -EINVAL;
366 
367 	input /= 1000;
368 	output /= 1000;
369 
370 	n = output * pdiv / input;
371 	if (n < 16)
372 		n = 16;
373 	fs->ndiv = n - 16; /* Converting formula value to reg value */
374 
375 	return 0;
376 }
377 
378 static long quadfs_pll_fs660c32_round_rate(struct clk_hw *hw,
379 					   unsigned long rate,
380 					   unsigned long *prate)
381 {
382 	struct stm_fs params;
383 
384 	if (clk_fs660c32_vco_get_params(*prate, rate, &params))
385 		return rate;
386 
387 	clk_fs660c32_vco_get_rate(*prate, &params, &rate);
388 
389 	pr_debug("%s: %s new rate %ld [ndiv=%u]\n",
390 		 __func__, clk_hw_get_name(hw),
391 		 rate, (unsigned int)params.ndiv);
392 
393 	return rate;
394 }
395 
396 static int quadfs_pll_fs660c32_set_rate(struct clk_hw *hw, unsigned long rate,
397 				unsigned long parent_rate)
398 {
399 	struct st_clk_quadfs_pll *pll = to_quadfs_pll(hw);
400 	struct stm_fs params;
401 	long hwrate = 0;
402 	unsigned long flags = 0;
403 	int ret;
404 
405 	if (!rate || !parent_rate)
406 		return -EINVAL;
407 
408 	ret = clk_fs660c32_vco_get_params(parent_rate, rate, &params);
409 	if (ret)
410 		return ret;
411 
412 	clk_fs660c32_vco_get_rate(parent_rate, &params, &hwrate);
413 
414 	pr_debug("%s: %s new rate %ld [ndiv=0x%x]\n",
415 		 __func__, clk_hw_get_name(hw),
416 		 hwrate, (unsigned int)params.ndiv);
417 
418 	if (!hwrate)
419 		return -EINVAL;
420 
421 	pll->ndiv = params.ndiv;
422 
423 	if (pll->lock)
424 		spin_lock_irqsave(pll->lock, flags);
425 
426 	CLKGEN_WRITE(pll, ndiv, pll->ndiv);
427 
428 	if (pll->lock)
429 		spin_unlock_irqrestore(pll->lock, flags);
430 
431 	return 0;
432 }
433 
434 static const struct clk_ops st_quadfs_pll_c32_ops = {
435 	.enable		= quadfs_pll_enable,
436 	.disable	= quadfs_pll_disable,
437 	.is_enabled	= quadfs_pll_is_enabled,
438 	.recalc_rate	= quadfs_pll_fs660c32_recalc_rate,
439 	.round_rate	= quadfs_pll_fs660c32_round_rate,
440 	.set_rate	= quadfs_pll_fs660c32_set_rate,
441 };
442 
443 static struct clk * __init st_clk_register_quadfs_pll(
444 		const char *name, const char *parent_name,
445 		struct clkgen_quadfs_data *quadfs, void __iomem *reg,
446 		spinlock_t *lock)
447 {
448 	struct st_clk_quadfs_pll *pll;
449 	struct clk *clk;
450 	struct clk_init_data init;
451 
452 	/*
453 	 * Sanity check required pointers.
454 	 */
455 	if (WARN_ON(!name || !parent_name))
456 		return ERR_PTR(-EINVAL);
457 
458 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
459 	if (!pll)
460 		return ERR_PTR(-ENOMEM);
461 
462 	init.name = name;
463 	init.ops = quadfs->pll_ops;
464 	init.flags = CLK_GET_RATE_NOCACHE;
465 	init.parent_names = &parent_name;
466 	init.num_parents = 1;
467 
468 	pll->data = quadfs;
469 	pll->regs_base = reg;
470 	pll->lock = lock;
471 	pll->hw.init = &init;
472 
473 	clk = clk_register(NULL, &pll->hw);
474 
475 	if (IS_ERR(clk))
476 		kfree(pll);
477 
478 	return clk;
479 }
480 
481 /**
482  * DOC: A digital frequency synthesizer
483  *
484  * Traits of this clock:
485  * prepare - clk_(un)prepare only ensures parent is (un)prepared
486  * enable - clk_enable and clk_disable are functional
487  * rate - set rate is functional
488  * parent - fixed parent.  No clk_set_parent support
489  */
490 
491 /*
492  * struct st_clk_quadfs_fsynth - One clock output from a four channel digital
493  *                                  frequency synthesizer (fsynth) block.
494  *
495  * @hw: handle between common and hardware-specific interfaces
496  *
497  * @nsb: regmap field in the output control register for the digital
498  *       standby of this fsynth channel. This control is active low so
499  *       the channel is in standby when the control bit is cleared.
500  *
501  * @nsdiv: regmap field in the output control register for
502  *          for the optional divide by 3 of this fsynth channel. This control
503  *          is active low so the divide by 3 is active when the control bit is
504  *          cleared and the divide is bypassed when the bit is set.
505  */
506 struct st_clk_quadfs_fsynth {
507 	struct clk_hw	hw;
508 	void __iomem	*regs_base;
509 	spinlock_t	*lock;
510 	struct clkgen_quadfs_data *data;
511 
512 	u32 chan;
513 	/*
514 	 * Cached hardware values from set_rate so we can program the
515 	 * hardware in enable. There are two reasons for this:
516 	 *
517 	 *  1. The registers may not be writable until the parent has been
518 	 *     enabled.
519 	 *
520 	 *  2. It restores the clock rate when a driver does an enable
521 	 *     on PM restore, after a suspend to RAM has lost the hardware
522 	 *     setup.
523 	 */
524 	u32 md;
525 	u32 pe;
526 	u32 sdiv;
527 	u32 nsdiv;
528 };
529 
530 #define to_quadfs_fsynth(_hw) \
531 	container_of(_hw, struct st_clk_quadfs_fsynth, hw)
532 
533 static void quadfs_fsynth_program_enable(struct st_clk_quadfs_fsynth *fs)
534 {
535 	/*
536 	 * Pulse the program enable register lsb to make the hardware take
537 	 * notice of the new md/pe values with a glitchless transition.
538 	 */
539 	CLKGEN_WRITE(fs, en[fs->chan], 1);
540 	CLKGEN_WRITE(fs, en[fs->chan], 0);
541 }
542 
543 static void quadfs_fsynth_program_rate(struct st_clk_quadfs_fsynth *fs)
544 {
545 	unsigned long flags = 0;
546 
547 	/*
548 	 * Ensure the md/pe parameters are ignored while we are
549 	 * reprogramming them so we can get a glitchless change
550 	 * when fine tuning the speed of a running clock.
551 	 */
552 	CLKGEN_WRITE(fs, en[fs->chan], 0);
553 
554 	CLKGEN_WRITE(fs, mdiv[fs->chan], fs->md);
555 	CLKGEN_WRITE(fs, pe[fs->chan], fs->pe);
556 	CLKGEN_WRITE(fs, sdiv[fs->chan], fs->sdiv);
557 
558 	if (fs->lock)
559 		spin_lock_irqsave(fs->lock, flags);
560 
561 	if (fs->data->nsdiv_present)
562 		CLKGEN_WRITE(fs, nsdiv[fs->chan], fs->nsdiv);
563 
564 	if (fs->lock)
565 		spin_unlock_irqrestore(fs->lock, flags);
566 }
567 
568 static int quadfs_fsynth_enable(struct clk_hw *hw)
569 {
570 	struct st_clk_quadfs_fsynth *fs = to_quadfs_fsynth(hw);
571 	unsigned long flags = 0;
572 
573 	pr_debug("%s: %s\n", __func__, clk_hw_get_name(hw));
574 
575 	quadfs_fsynth_program_rate(fs);
576 
577 	if (fs->lock)
578 		spin_lock_irqsave(fs->lock, flags);
579 
580 	CLKGEN_WRITE(fs, nsb[fs->chan], !fs->data->standby_polarity);
581 
582 	if (fs->data->nrst_present)
583 		CLKGEN_WRITE(fs, nrst[fs->chan], 0);
584 
585 	if (fs->lock)
586 		spin_unlock_irqrestore(fs->lock, flags);
587 
588 	quadfs_fsynth_program_enable(fs);
589 
590 	return 0;
591 }
592 
593 static void quadfs_fsynth_disable(struct clk_hw *hw)
594 {
595 	struct st_clk_quadfs_fsynth *fs = to_quadfs_fsynth(hw);
596 	unsigned long flags = 0;
597 
598 	pr_debug("%s: %s\n", __func__, clk_hw_get_name(hw));
599 
600 	if (fs->lock)
601 		spin_lock_irqsave(fs->lock, flags);
602 
603 	CLKGEN_WRITE(fs, nsb[fs->chan], fs->data->standby_polarity);
604 
605 	if (fs->lock)
606 		spin_unlock_irqrestore(fs->lock, flags);
607 }
608 
609 static int quadfs_fsynth_is_enabled(struct clk_hw *hw)
610 {
611 	struct st_clk_quadfs_fsynth *fs = to_quadfs_fsynth(hw);
612 	u32 nsb = CLKGEN_READ(fs, nsb[fs->chan]);
613 
614 	pr_debug("%s: %s enable bit = 0x%x\n",
615 		 __func__, clk_hw_get_name(hw), nsb);
616 
617 	return fs->data->standby_polarity ? !nsb : !!nsb;
618 }
619 
620 #define P20		(uint64_t)(1 << 20)
621 
622 static int clk_fs660c32_dig_get_rate(unsigned long input,
623 				const struct stm_fs *fs, unsigned long *rate)
624 {
625 	unsigned long s = (1 << fs->sdiv);
626 	unsigned long ns;
627 	uint64_t res;
628 
629 	/*
630 	 * 'nsdiv' is a register value ('BIN') which is translated
631 	 * to a decimal value according to following rules.
632 	 *
633 	 *     nsdiv      ns.dec
634 	 *       0        3
635 	 *       1        1
636 	 */
637 	ns = (fs->nsdiv == 1) ? 1 : 3;
638 
639 	res = (P20 * (32 + fs->mdiv) + 32 * fs->pe) * s * ns;
640 	*rate = (unsigned long)div64_u64(input * P20 * 32, res);
641 
642 	return 0;
643 }
644 
645 
646 static int clk_fs660c32_get_pe(int m, int si, unsigned long *deviation,
647 		signed long input, unsigned long output, uint64_t *p,
648 		struct stm_fs *fs)
649 {
650 	unsigned long new_freq, new_deviation;
651 	struct stm_fs fs_tmp;
652 	uint64_t val;
653 
654 	val = (uint64_t)output << si;
655 
656 	*p = (uint64_t)input * P20 - (32LL  + (uint64_t)m) * val * (P20 / 32LL);
657 
658 	*p = div64_u64(*p, val);
659 
660 	if (*p > 32767LL)
661 		return 1;
662 
663 	fs_tmp.mdiv = (unsigned long) m;
664 	fs_tmp.pe = (unsigned long)*p;
665 	fs_tmp.sdiv = si;
666 	fs_tmp.nsdiv = 1;
667 
668 	clk_fs660c32_dig_get_rate(input, &fs_tmp, &new_freq);
669 
670 	new_deviation = abs(output - new_freq);
671 
672 	if (new_deviation < *deviation) {
673 		fs->mdiv = m;
674 		fs->pe = (unsigned long)*p;
675 		fs->sdiv = si;
676 		fs->nsdiv = 1;
677 		*deviation = new_deviation;
678 	}
679 	return 0;
680 }
681 
682 static int clk_fs660c32_dig_get_params(unsigned long input,
683 		unsigned long output, struct stm_fs *fs)
684 {
685 	int si;	/* sdiv_reg (8 downto 0) */
686 	int m; /* md value */
687 	unsigned long new_freq, new_deviation;
688 	/* initial condition to say: "infinite deviation" */
689 	unsigned long deviation = ~0;
690 	uint64_t p, p1, p2;	/* pe value */
691 	int r1, r2;
692 
693 	struct stm_fs fs_tmp;
694 
695 	for (si = 0; (si <= 8) && deviation; si++) {
696 
697 		/* Boundary test to avoid useless iteration */
698 		r1 = clk_fs660c32_get_pe(0, si, &deviation,
699 				input, output, &p1, fs);
700 		r2 = clk_fs660c32_get_pe(31, si, &deviation,
701 				input, output, &p2, fs);
702 
703 		/* No solution */
704 		if (r1 && r2 && (p1 > p2))
705 			continue;
706 
707 		/* Try to find best deviation */
708 		for (m = 1; (m < 31) && deviation; m++)
709 			clk_fs660c32_get_pe(m, si, &deviation,
710 					input, output, &p, fs);
711 
712 	}
713 
714 	if (deviation == ~0) /* No solution found */
715 		return -1;
716 
717 	/* pe fine tuning if deviation not 0: +/- 2 around computed pe value */
718 	if (deviation) {
719 		fs_tmp.mdiv = fs->mdiv;
720 		fs_tmp.sdiv = fs->sdiv;
721 		fs_tmp.nsdiv = fs->nsdiv;
722 
723 		if (fs->pe > 2)
724 			p2 = fs->pe - 2;
725 		else
726 			p2 = 0;
727 
728 		for (; p2 < 32768ll && (p2 <= (fs->pe + 2)); p2++) {
729 			fs_tmp.pe = (unsigned long)p2;
730 
731 			clk_fs660c32_dig_get_rate(input, &fs_tmp, &new_freq);
732 
733 			new_deviation = abs(output - new_freq);
734 
735 			/* Check if this is a better solution */
736 			if (new_deviation < deviation) {
737 				fs->pe = (unsigned long)p2;
738 				deviation = new_deviation;
739 
740 			}
741 		}
742 	}
743 	return 0;
744 }
745 
746 static int quadfs_fsynt_get_hw_value_for_recalc(struct st_clk_quadfs_fsynth *fs,
747 		struct stm_fs *params)
748 {
749 	/*
750 	 * Get the initial hardware values for recalc_rate
751 	 */
752 	params->mdiv	= CLKGEN_READ(fs, mdiv[fs->chan]);
753 	params->pe	= CLKGEN_READ(fs, pe[fs->chan]);
754 	params->sdiv	= CLKGEN_READ(fs, sdiv[fs->chan]);
755 
756 	if (fs->data->nsdiv_present)
757 		params->nsdiv = CLKGEN_READ(fs, nsdiv[fs->chan]);
758 	else
759 		params->nsdiv = 1;
760 
761 	/*
762 	 * If All are NULL then assume no clock rate is programmed.
763 	 */
764 	if (!params->mdiv && !params->pe && !params->sdiv)
765 		return 1;
766 
767 	fs->md = params->mdiv;
768 	fs->pe = params->pe;
769 	fs->sdiv = params->sdiv;
770 	fs->nsdiv = params->nsdiv;
771 
772 	return 0;
773 }
774 
775 static long quadfs_find_best_rate(struct clk_hw *hw, unsigned long drate,
776 				unsigned long prate, struct stm_fs *params)
777 {
778 	struct st_clk_quadfs_fsynth *fs = to_quadfs_fsynth(hw);
779 	int (*clk_fs_get_rate)(unsigned long ,
780 				const struct stm_fs *, unsigned long *);
781 	int (*clk_fs_get_params)(unsigned long, unsigned long, struct stm_fs *);
782 	unsigned long rate = 0;
783 
784 	clk_fs_get_rate = fs->data->get_rate;
785 	clk_fs_get_params = fs->data->get_params;
786 
787 	if (!clk_fs_get_params(prate, drate, params))
788 		clk_fs_get_rate(prate, params, &rate);
789 
790 	return rate;
791 }
792 
793 static unsigned long quadfs_recalc_rate(struct clk_hw *hw,
794 		unsigned long parent_rate)
795 {
796 	struct st_clk_quadfs_fsynth *fs = to_quadfs_fsynth(hw);
797 	unsigned long rate = 0;
798 	struct stm_fs params;
799 	int (*clk_fs_get_rate)(unsigned long ,
800 				const struct stm_fs *, unsigned long *);
801 
802 	clk_fs_get_rate = fs->data->get_rate;
803 
804 	if (quadfs_fsynt_get_hw_value_for_recalc(fs, &params))
805 		return 0;
806 
807 	if (clk_fs_get_rate(parent_rate, &params, &rate)) {
808 		pr_err("%s:%s error calculating rate\n",
809 		       clk_hw_get_name(hw), __func__);
810 	}
811 
812 	pr_debug("%s:%s rate %lu\n", clk_hw_get_name(hw), __func__, rate);
813 
814 	return rate;
815 }
816 
817 static long quadfs_round_rate(struct clk_hw *hw, unsigned long rate,
818 				     unsigned long *prate)
819 {
820 	struct stm_fs params;
821 
822 	rate = quadfs_find_best_rate(hw, rate, *prate, &params);
823 
824 	pr_debug("%s: %s new rate %ld [sdiv=0x%x,md=0x%x,pe=0x%x,nsdiv3=%u]\n",
825 		 __func__, clk_hw_get_name(hw),
826 		 rate, (unsigned int)params.sdiv, (unsigned int)params.mdiv,
827 			 (unsigned int)params.pe, (unsigned int)params.nsdiv);
828 
829 	return rate;
830 }
831 
832 
833 static void quadfs_program_and_enable(struct st_clk_quadfs_fsynth *fs,
834 		struct stm_fs *params)
835 {
836 	fs->md = params->mdiv;
837 	fs->pe = params->pe;
838 	fs->sdiv = params->sdiv;
839 	fs->nsdiv = params->nsdiv;
840 
841 	/*
842 	 * In some integrations you can only change the fsynth programming when
843 	 * the parent entity containing it is enabled.
844 	 */
845 	quadfs_fsynth_program_rate(fs);
846 	quadfs_fsynth_program_enable(fs);
847 }
848 
849 static int quadfs_set_rate(struct clk_hw *hw, unsigned long rate,
850 				  unsigned long parent_rate)
851 {
852 	struct st_clk_quadfs_fsynth *fs = to_quadfs_fsynth(hw);
853 	struct stm_fs params;
854 	long hwrate;
855 
856 	if (!rate || !parent_rate)
857 		return -EINVAL;
858 
859 	memset(&params, 0, sizeof(struct stm_fs));
860 
861 	hwrate = quadfs_find_best_rate(hw, rate, parent_rate, &params);
862 	if (!hwrate)
863 		return -EINVAL;
864 
865 	quadfs_program_and_enable(fs, &params);
866 
867 	return 0;
868 }
869 
870 
871 
872 static const struct clk_ops st_quadfs_ops = {
873 	.enable		= quadfs_fsynth_enable,
874 	.disable	= quadfs_fsynth_disable,
875 	.is_enabled	= quadfs_fsynth_is_enabled,
876 	.round_rate	= quadfs_round_rate,
877 	.set_rate	= quadfs_set_rate,
878 	.recalc_rate	= quadfs_recalc_rate,
879 };
880 
881 static struct clk * __init st_clk_register_quadfs_fsynth(
882 		const char *name, const char *parent_name,
883 		struct clkgen_quadfs_data *quadfs, void __iomem *reg, u32 chan,
884 		unsigned long flags, spinlock_t *lock)
885 {
886 	struct st_clk_quadfs_fsynth *fs;
887 	struct clk *clk;
888 	struct clk_init_data init;
889 
890 	/*
891 	 * Sanity check required pointers, note that nsdiv3 is optional.
892 	 */
893 	if (WARN_ON(!name || !parent_name))
894 		return ERR_PTR(-EINVAL);
895 
896 	fs = kzalloc(sizeof(*fs), GFP_KERNEL);
897 	if (!fs)
898 		return ERR_PTR(-ENOMEM);
899 
900 	init.name = name;
901 	init.ops = &st_quadfs_ops;
902 	init.flags = flags | CLK_GET_RATE_NOCACHE;
903 	init.parent_names = &parent_name;
904 	init.num_parents = 1;
905 
906 	fs->data = quadfs;
907 	fs->regs_base = reg;
908 	fs->chan = chan;
909 	fs->lock = lock;
910 	fs->hw.init = &init;
911 
912 	clk = clk_register(NULL, &fs->hw);
913 
914 	if (IS_ERR(clk))
915 		kfree(fs);
916 
917 	return clk;
918 }
919 
920 static void __init st_of_create_quadfs_fsynths(
921 		struct device_node *np, const char *pll_name,
922 		struct clkgen_quadfs_data_clks *quadfs, void __iomem *reg,
923 		spinlock_t *lock)
924 {
925 	struct clk_onecell_data *clk_data;
926 	int fschan;
927 
928 	clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
929 	if (!clk_data)
930 		return;
931 
932 	clk_data->clk_num = QUADFS_MAX_CHAN;
933 	clk_data->clks = kcalloc(QUADFS_MAX_CHAN, sizeof(struct clk *),
934 				 GFP_KERNEL);
935 
936 	if (!clk_data->clks) {
937 		kfree(clk_data);
938 		return;
939 	}
940 
941 	for (fschan = 0; fschan < QUADFS_MAX_CHAN; fschan++) {
942 		struct clk *clk;
943 		const char *clk_name;
944 		unsigned long flags = 0;
945 
946 		if (quadfs->outputs) {
947 			clk_name = quadfs->outputs[fschan].name;
948 			flags = quadfs->outputs[fschan].flags;
949 		} else {
950 			if (of_property_read_string_index(np,
951 							"clock-output-names",
952 							fschan, &clk_name))
953 				break;
954 			of_clk_detect_critical(np, fschan, &flags);
955 		}
956 
957 		/*
958 		 * If we read an empty clock name then the channel is unused
959 		 */
960 		if (*clk_name == '\0')
961 			continue;
962 
963 		clk = st_clk_register_quadfs_fsynth(clk_name, pll_name,
964 						    quadfs->data, reg, fschan,
965 						    flags, lock);
966 
967 		/*
968 		 * If there was an error registering this clock output, clean
969 		 * up and move on to the next one.
970 		 */
971 		if (!IS_ERR(clk)) {
972 			clk_data->clks[fschan] = clk;
973 			pr_debug("%s: parent %s rate %u\n",
974 				__clk_get_name(clk),
975 				__clk_get_name(clk_get_parent(clk)),
976 				(unsigned int)clk_get_rate(clk));
977 		}
978 	}
979 
980 	of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
981 }
982 
983 static void __init st_of_quadfs_setup(struct device_node *np,
984 		struct clkgen_quadfs_data_clks *datac)
985 {
986 	struct clk *clk;
987 	const char *pll_name, *clk_parent_name;
988 	void __iomem *reg;
989 	spinlock_t *lock;
990 
991 	/*
992 	 * First check for reg property within the node to keep backward
993 	 * compatibility, then if reg doesn't exist look at the parent node
994 	 */
995 	reg = of_iomap(np, 0);
996 	if (!reg) {
997 		reg = of_iomap(of_get_parent(np), 0);
998 		if (!reg) {
999 			pr_err("%s: Failed to get base address\n", __func__);
1000 			return;
1001 		}
1002 	}
1003 
1004 	clk_parent_name = of_clk_get_parent_name(np, 0);
1005 	if (!clk_parent_name)
1006 		return;
1007 
1008 	pll_name = kasprintf(GFP_KERNEL, "%pOFn.pll", np);
1009 	if (!pll_name)
1010 		return;
1011 
1012 	lock = kzalloc(sizeof(*lock), GFP_KERNEL);
1013 	if (!lock)
1014 		goto err_exit;
1015 
1016 	spin_lock_init(lock);
1017 
1018 	clk = st_clk_register_quadfs_pll(pll_name, clk_parent_name, datac->data,
1019 			reg, lock);
1020 	if (IS_ERR(clk))
1021 		goto err_exit;
1022 	else
1023 		pr_debug("%s: parent %s rate %u\n",
1024 			__clk_get_name(clk),
1025 			__clk_get_name(clk_get_parent(clk)),
1026 			(unsigned int)clk_get_rate(clk));
1027 
1028 	st_of_create_quadfs_fsynths(np, pll_name, datac, reg, lock);
1029 
1030 err_exit:
1031 	kfree(pll_name); /* No longer need local copy of the PLL name */
1032 }
1033 
1034 static void __init st_of_quadfs660C_setup(struct device_node *np)
1035 {
1036 	st_of_quadfs_setup(np,
1037 		(struct clkgen_quadfs_data_clks *) &st_fs660c32_C_data);
1038 }
1039 CLK_OF_DECLARE(quadfs660C, "st,quadfs-pll", st_of_quadfs660C_setup);
1040 
1041 static void __init st_of_quadfs660D_setup(struct device_node *np)
1042 {
1043 	st_of_quadfs_setup(np,
1044 		(struct clkgen_quadfs_data_clks *) &st_fs660c32_D_data);
1045 }
1046 CLK_OF_DECLARE(quadfs660D, "st,quadfs", st_of_quadfs660D_setup);
1047 
1048 static void __init st_of_quadfs660D0_setup(struct device_node *np)
1049 {
1050 	st_of_quadfs_setup(np,
1051 		(struct clkgen_quadfs_data_clks *) &st_fs660c32_D0_data);
1052 }
1053 CLK_OF_DECLARE(quadfs660D0, "st,quadfs-d0", st_of_quadfs660D0_setup);
1054 
1055 static void __init st_of_quadfs660D2_setup(struct device_node *np)
1056 {
1057 	st_of_quadfs_setup(np,
1058 		(struct clkgen_quadfs_data_clks *) &st_fs660c32_D2_data);
1059 }
1060 CLK_OF_DECLARE(quadfs660D2, "st,quadfs-d2", st_of_quadfs660D2_setup);
1061 
1062 static void __init st_of_quadfs660D3_setup(struct device_node *np)
1063 {
1064 	st_of_quadfs_setup(np,
1065 		(struct clkgen_quadfs_data_clks *) &st_fs660c32_D3_data);
1066 }
1067 CLK_OF_DECLARE(quadfs660D3, "st,quadfs-d3", st_of_quadfs660D3_setup);
1068