xref: /openbmc/linux/drivers/media/i2c/ccs-pll.c (revision 594f1e93bb2c48bcc14a020448b46eed15be7ef7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * drivers/media/i2c/ccs-pll.c
4  *
5  * Generic MIPI CCS/SMIA/SMIA++ PLL calculator
6  *
7  * Copyright (C) 2020 Intel Corporation
8  * Copyright (C) 2011--2012 Nokia Corporation
9  * Contact: Sakari Ailus <sakari.ailus@linux.intel.com>
10  */
11 
12 #include <linux/device.h>
13 #include <linux/gcd.h>
14 #include <linux/lcm.h>
15 #include <linux/module.h>
16 
17 #include "ccs-pll.h"
18 
19 /* Return an even number or one. */
20 static inline uint32_t clk_div_even(uint32_t a)
21 {
22 	return max_t(uint32_t, 1, a & ~1);
23 }
24 
25 /* Return an even number or one. */
26 static inline uint32_t clk_div_even_up(uint32_t a)
27 {
28 	if (a == 1)
29 		return 1;
30 	return (a + 1) & ~1;
31 }
32 
33 static inline uint32_t is_one_or_even(uint32_t a)
34 {
35 	if (a == 1)
36 		return 1;
37 	if (a & 1)
38 		return 0;
39 
40 	return 1;
41 }
42 
43 static inline uint32_t one_or_more(uint32_t a)
44 {
45 	return a ?: 1;
46 }
47 
48 static int bounds_check(struct device *dev, uint32_t val,
49 			uint32_t min, uint32_t max, const char *prefix,
50 			char *str)
51 {
52 	if (val >= min && val <= max)
53 		return 0;
54 
55 	dev_dbg(dev, "%s_%s out of bounds: %d (%d--%d)\n", prefix,
56 		str, val, min, max);
57 
58 	return -EINVAL;
59 }
60 
61 #define PLL_OP 1
62 #define PLL_VT 2
63 
64 static const char *pll_string(unsigned int which)
65 {
66 	switch (which) {
67 	case PLL_OP:
68 		return "op";
69 	case PLL_VT:
70 		return "vt";
71 	}
72 
73 	return NULL;
74 }
75 
76 #define PLL_FL(f) CCS_PLL_FLAG_##f
77 
78 static void print_pll(struct device *dev, struct ccs_pll *pll)
79 {
80 	const struct {
81 		struct ccs_pll_branch_fr *fr;
82 		struct ccs_pll_branch_bk *bk;
83 		unsigned int which;
84 	} branches[] = {
85 		{ &pll->vt_fr, &pll->vt_bk, PLL_VT },
86 		{ &pll->op_fr, &pll->op_bk, PLL_OP }
87 	}, *br;
88 	unsigned int i;
89 
90 	dev_dbg(dev, "ext_clk_freq_hz\t\t%u\n", pll->ext_clk_freq_hz);
91 
92 	for (i = 0, br = branches; i < ARRAY_SIZE(branches); i++, br++) {
93 		const char *s = pll_string(br->which);
94 
95 		if (br->which == PLL_VT) {
96 			dev_dbg(dev, "%s_pre_pll_clk_div\t\t%u\n",  s,
97 				br->fr->pre_pll_clk_div);
98 			dev_dbg(dev, "%s_pll_multiplier\t\t%u\n",  s,
99 				br->fr->pll_multiplier);
100 
101 			dev_dbg(dev, "%s_pll_ip_clk_freq_hz\t%u\n", s,
102 				br->fr->pll_ip_clk_freq_hz);
103 			dev_dbg(dev, "%s_pll_op_clk_freq_hz\t%u\n", s,
104 				br->fr->pll_op_clk_freq_hz);
105 		}
106 
107 		if (!(pll->flags & CCS_PLL_FLAG_NO_OP_CLOCKS) ||
108 		    br->which == PLL_VT) {
109 			dev_dbg(dev, "%s_sys_clk_div\t\t%u\n",  s,
110 				br->bk->sys_clk_div);
111 			dev_dbg(dev, "%s_pix_clk_div\t\t%u\n", s,
112 				br->bk->pix_clk_div);
113 
114 			dev_dbg(dev, "%s_sys_clk_freq_hz\t%u\n", s,
115 				br->bk->sys_clk_freq_hz);
116 			dev_dbg(dev, "%s_pix_clk_freq_hz\t%u\n", s,
117 				br->bk->pix_clk_freq_hz);
118 		}
119 	}
120 
121 	dev_dbg(dev, "flags%s%s%s%s%s%s\n",
122 		pll->flags & PLL_FL(LANE_SPEED_MODEL) ? " lane-speed" : "",
123 		pll->flags & PLL_FL(LINK_DECOUPLED) ? " link-decoupled" : "",
124 		pll->flags & PLL_FL(EXT_IP_PLL_DIVIDER) ?
125 		" ext-ip-pll-divider" : "",
126 		pll->flags & PLL_FL(FLEXIBLE_OP_PIX_CLK_DIV) ?
127 		" flexible-op-pix-div" : "",
128 		pll->flags & PLL_FL(FIFO_DERATING) ? " fifo-derating" : "",
129 		pll->flags & PLL_FL(FIFO_OVERRATING) ? " fifo-overrating" : "");
130 }
131 
132 static int check_fr_bounds(struct device *dev,
133 			   const struct ccs_pll_limits *lim,
134 			   struct ccs_pll *pll, unsigned int which)
135 {
136 	const struct ccs_pll_branch_limits_fr *lim_fr;
137 	struct ccs_pll_branch_fr *pll_fr;
138 	const char *s = pll_string(which);
139 	int rval;
140 
141 	if (which == PLL_OP) {
142 		lim_fr = &lim->op_fr;
143 		pll_fr = &pll->op_fr;
144 	} else {
145 		lim_fr = &lim->vt_fr;
146 		pll_fr = &pll->vt_fr;
147 	}
148 
149 	rval = bounds_check(dev, pll_fr->pre_pll_clk_div,
150 			    lim_fr->min_pre_pll_clk_div,
151 			    lim_fr->max_pre_pll_clk_div, s, "pre_pll_clk_div");
152 
153 	if (!rval)
154 		rval = bounds_check(dev, pll_fr->pll_ip_clk_freq_hz,
155 				    lim_fr->min_pll_ip_clk_freq_hz,
156 				    lim_fr->max_pll_ip_clk_freq_hz,
157 				    s, "pll_ip_clk_freq_hz");
158 	if (!rval)
159 		rval = bounds_check(dev, pll_fr->pll_multiplier,
160 				    lim_fr->min_pll_multiplier,
161 				    lim_fr->max_pll_multiplier,
162 				    s, "pll_multiplier");
163 	if (!rval)
164 		rval = bounds_check(dev, pll_fr->pll_op_clk_freq_hz,
165 				    lim_fr->min_pll_op_clk_freq_hz,
166 				    lim_fr->max_pll_op_clk_freq_hz,
167 				    s, "pll_op_clk_freq_hz");
168 
169 	return rval;
170 }
171 
172 static int check_bk_bounds(struct device *dev,
173 			   const struct ccs_pll_limits *lim,
174 			   struct ccs_pll *pll, unsigned int which)
175 {
176 	const struct ccs_pll_branch_limits_bk *lim_bk;
177 	struct ccs_pll_branch_bk *pll_bk;
178 	const char *s = pll_string(which);
179 	int rval;
180 
181 	if (which == PLL_OP) {
182 		if (pll->flags & CCS_PLL_FLAG_NO_OP_CLOCKS)
183 			return 0;
184 
185 		lim_bk = &lim->op_bk;
186 		pll_bk = &pll->op_bk;
187 	} else {
188 		lim_bk = &lim->vt_bk;
189 		pll_bk = &pll->vt_bk;
190 	}
191 
192 	rval = bounds_check(dev, pll_bk->sys_clk_div,
193 			    lim_bk->min_sys_clk_div,
194 			    lim_bk->max_sys_clk_div, s, "op_sys_clk_div");
195 	if (!rval)
196 		rval = bounds_check(dev, pll_bk->sys_clk_freq_hz,
197 				    lim_bk->min_sys_clk_freq_hz,
198 				    lim_bk->max_sys_clk_freq_hz,
199 				    s, "sys_clk_freq_hz");
200 	if (!rval)
201 		rval = bounds_check(dev, pll_bk->sys_clk_div,
202 				    lim_bk->min_sys_clk_div,
203 				    lim_bk->max_sys_clk_div,
204 				    s, "sys_clk_div");
205 	if (!rval)
206 		rval = bounds_check(dev, pll_bk->pix_clk_freq_hz,
207 				    lim_bk->min_pix_clk_freq_hz,
208 				    lim_bk->max_pix_clk_freq_hz,
209 				    s, "pix_clk_freq_hz");
210 
211 	return rval;
212 }
213 
214 static int check_ext_bounds(struct device *dev, struct ccs_pll *pll)
215 {
216 	if (!(pll->flags & CCS_PLL_FLAG_FIFO_DERATING) &&
217 	    pll->pixel_rate_pixel_array > pll->pixel_rate_csi) {
218 		dev_dbg(dev, "device does not support derating\n");
219 		return -EINVAL;
220 	}
221 
222 	if (!(pll->flags & CCS_PLL_FLAG_FIFO_OVERRATING) &&
223 	    pll->pixel_rate_pixel_array < pll->pixel_rate_csi) {
224 		dev_dbg(dev, "device does not support overrating\n");
225 		return -EINVAL;
226 	}
227 
228 	return 0;
229 }
230 
231 #define CPHY_CONST		7
232 #define DPHY_CONST		16
233 #define PHY_CONST_DIV		16
234 
235 static void
236 ccs_pll_calculate_vt(struct device *dev, const struct ccs_pll_limits *lim,
237 		     const struct ccs_pll_branch_limits_bk *op_lim_bk,
238 		     struct ccs_pll *pll, struct ccs_pll_branch_fr *pll_fr,
239 		     struct ccs_pll_branch_bk *op_pll_bk, bool cphy,
240 		     uint32_t phy_const)
241 {
242 	uint16_t sys_div;
243 	uint16_t best_pix_div = SHRT_MAX >> 1;
244 	uint16_t vt_op_binning_div;
245 	uint16_t min_vt_div, max_vt_div, vt_div;
246 	uint16_t min_sys_div, max_sys_div;
247 
248 	if (pll->flags & CCS_PLL_FLAG_NO_OP_CLOCKS)
249 		goto out_calc_pixel_rate;
250 
251 	/*
252 	 * Find out whether a sensor supports derating. If it does not, VT and
253 	 * OP domains are required to run at the same pixel rate.
254 	 */
255 	if (!(pll->flags & CCS_PLL_FLAG_FIFO_DERATING)) {
256 		min_vt_div =
257 			op_pll_bk->sys_clk_div * op_pll_bk->pix_clk_div
258 			* pll->vt_lanes * phy_const
259 			/ pll->op_lanes / PHY_CONST_DIV;
260 	} else {
261 		/*
262 		 * Some sensors perform analogue binning and some do this
263 		 * digitally. The ones doing this digitally can be roughly be
264 		 * found out using this formula. The ones doing this digitally
265 		 * should run at higher clock rate, so smaller divisor is used
266 		 * on video timing side.
267 		 */
268 		if (lim->min_line_length_pck_bin > lim->min_line_length_pck
269 		    / pll->binning_horizontal)
270 			vt_op_binning_div = pll->binning_horizontal;
271 		else
272 			vt_op_binning_div = 1;
273 		dev_dbg(dev, "vt_op_binning_div: %u\n", vt_op_binning_div);
274 
275 		/*
276 		 * Profile 2 supports vt_pix_clk_div E [4, 10]
277 		 *
278 		 * Horizontal binning can be used as a base for difference in
279 		 * divisors. One must make sure that horizontal blanking is
280 		 * enough to accommodate the CSI-2 sync codes.
281 		 *
282 		 * Take scaling factor and number of VT lanes into account as well.
283 		 *
284 		 * Find absolute limits for the factor of vt divider.
285 		 */
286 		dev_dbg(dev, "scale_m: %u\n", pll->scale_m);
287 		min_vt_div =
288 			DIV_ROUND_UP(pll->bits_per_pixel
289 				     * op_pll_bk->sys_clk_div * pll->scale_n
290 				     * pll->vt_lanes * phy_const,
291 				     (pll->flags &
292 				      CCS_PLL_FLAG_LANE_SPEED_MODEL ?
293 				      pll->csi2.lanes : 1)
294 				     * vt_op_binning_div * pll->scale_m
295 				     * PHY_CONST_DIV);
296 	}
297 
298 	/* Find smallest and biggest allowed vt divisor. */
299 	dev_dbg(dev, "min_vt_div: %u\n", min_vt_div);
300 	min_vt_div = max_t(uint16_t, min_vt_div,
301 			   DIV_ROUND_UP(pll_fr->pll_op_clk_freq_hz,
302 					lim->vt_bk.max_pix_clk_freq_hz));
303 	dev_dbg(dev, "min_vt_div: max_vt_pix_clk_freq_hz: %u\n",
304 		min_vt_div);
305 	min_vt_div = max_t(uint16_t, min_vt_div, lim->vt_bk.min_pix_clk_div
306 						 * lim->vt_bk.min_sys_clk_div);
307 	dev_dbg(dev, "min_vt_div: min_vt_clk_div: %u\n", min_vt_div);
308 
309 	max_vt_div = lim->vt_bk.max_sys_clk_div * lim->vt_bk.max_pix_clk_div;
310 	dev_dbg(dev, "max_vt_div: %u\n", max_vt_div);
311 	max_vt_div = min_t(uint16_t, max_vt_div,
312 			   DIV_ROUND_UP(pll_fr->pll_op_clk_freq_hz,
313 				      lim->vt_bk.min_pix_clk_freq_hz));
314 	dev_dbg(dev, "max_vt_div: min_vt_pix_clk_freq_hz: %u\n",
315 		max_vt_div);
316 
317 	/*
318 	 * Find limitsits for sys_clk_div. Not all values are possible
319 	 * with all values of pix_clk_div.
320 	 */
321 	min_sys_div = lim->vt_bk.min_sys_clk_div;
322 	dev_dbg(dev, "min_sys_div: %u\n", min_sys_div);
323 	min_sys_div = max_t(uint16_t, min_sys_div,
324 			    DIV_ROUND_UP(min_vt_div,
325 					 lim->vt_bk.max_pix_clk_div));
326 	dev_dbg(dev, "min_sys_div: max_vt_pix_clk_div: %u\n", min_sys_div);
327 	min_sys_div = max_t(uint16_t, min_sys_div,
328 			    pll_fr->pll_op_clk_freq_hz
329 			    / lim->vt_bk.max_sys_clk_freq_hz);
330 	dev_dbg(dev, "min_sys_div: max_pll_op_clk_freq_hz: %u\n", min_sys_div);
331 	min_sys_div = clk_div_even_up(min_sys_div);
332 	dev_dbg(dev, "min_sys_div: one or even: %u\n", min_sys_div);
333 
334 	max_sys_div = lim->vt_bk.max_sys_clk_div;
335 	dev_dbg(dev, "max_sys_div: %u\n", max_sys_div);
336 	max_sys_div = min_t(uint16_t, max_sys_div,
337 			    DIV_ROUND_UP(max_vt_div,
338 					 lim->vt_bk.min_pix_clk_div));
339 	dev_dbg(dev, "max_sys_div: min_vt_pix_clk_div: %u\n", max_sys_div);
340 	max_sys_div = min_t(uint16_t, max_sys_div,
341 			    DIV_ROUND_UP(pll_fr->pll_op_clk_freq_hz,
342 					 lim->vt_bk.min_pix_clk_freq_hz));
343 	dev_dbg(dev, "max_sys_div: min_vt_pix_clk_freq_hz: %u\n", max_sys_div);
344 
345 	/*
346 	 * Find pix_div such that a legal pix_div * sys_div results
347 	 * into a value which is not smaller than div, the desired
348 	 * divisor.
349 	 */
350 	for (vt_div = min_vt_div; vt_div <= max_vt_div;
351 	     vt_div += 2 - (vt_div & 1)) {
352 		for (sys_div = min_sys_div;
353 		     sys_div <= max_sys_div;
354 		     sys_div += 2 - (sys_div & 1)) {
355 			uint16_t pix_div = DIV_ROUND_UP(vt_div, sys_div);
356 			uint16_t rounded_div;
357 
358 			if (pix_div < lim->vt_bk.min_pix_clk_div
359 			    || pix_div > lim->vt_bk.max_pix_clk_div) {
360 				dev_dbg(dev,
361 					"pix_div %u too small or too big (%u--%u)\n",
362 					pix_div,
363 					lim->vt_bk.min_pix_clk_div,
364 					lim->vt_bk.max_pix_clk_div);
365 				continue;
366 			}
367 
368 			rounded_div = roundup(vt_div, best_pix_div);
369 
370 			/* Check if this one is better. */
371 			if (pix_div * sys_div <= rounded_div)
372 				best_pix_div = pix_div;
373 
374 			/* Bail out if we've already found the best value. */
375 			if (vt_div == rounded_div)
376 				break;
377 		}
378 		if (best_pix_div < SHRT_MAX >> 1)
379 			break;
380 	}
381 
382 	pll->vt_bk.sys_clk_div = DIV_ROUND_UP(vt_div, best_pix_div);
383 	pll->vt_bk.pix_clk_div = best_pix_div;
384 
385 	pll->vt_bk.sys_clk_freq_hz =
386 		pll_fr->pll_op_clk_freq_hz / pll->vt_bk.sys_clk_div;
387 	pll->vt_bk.pix_clk_freq_hz =
388 		pll->vt_bk.sys_clk_freq_hz / pll->vt_bk.pix_clk_div;
389 
390 out_calc_pixel_rate:
391 	pll->pixel_rate_pixel_array =
392 		pll->vt_bk.pix_clk_freq_hz * pll->vt_lanes;
393 }
394 
395 /*
396  * Heuristically guess the PLL tree for a given common multiplier and
397  * divisor. Begin with the operational timing and continue to video
398  * timing once operational timing has been verified.
399  *
400  * @mul is the PLL multiplier and @div is the common divisor
401  * (pre_pll_clk_div and op_sys_clk_div combined). The final PLL
402  * multiplier will be a multiple of @mul.
403  *
404  * @return Zero on success, error code on error.
405  */
406 static int
407 ccs_pll_calculate_op(struct device *dev, const struct ccs_pll_limits *lim,
408 		     const struct ccs_pll_branch_limits_fr *op_lim_fr,
409 		     const struct ccs_pll_branch_limits_bk *op_lim_bk,
410 		     struct ccs_pll *pll, struct ccs_pll_branch_fr *op_pll_fr,
411 		     struct ccs_pll_branch_bk *op_pll_bk, uint32_t mul,
412 		     uint32_t div, uint32_t l, bool cphy, uint32_t phy_const)
413 {
414 	/*
415 	 * Higher multipliers (and divisors) are often required than
416 	 * necessitated by the external clock and the output clocks.
417 	 * There are limits for all values in the clock tree. These
418 	 * are the minimum and maximum multiplier for mul.
419 	 */
420 	uint32_t more_mul_min, more_mul_max;
421 	uint32_t more_mul_factor;
422 	uint32_t i;
423 
424 	/*
425 	 * Get pre_pll_clk_div so that our pll_op_clk_freq_hz won't be
426 	 * too high.
427 	 */
428 	dev_dbg(dev, "op_pre_pll_clk_div %u\n", op_pll_fr->pre_pll_clk_div);
429 
430 	/* Don't go above max pll multiplier. */
431 	more_mul_max = op_lim_fr->max_pll_multiplier / mul;
432 	dev_dbg(dev, "more_mul_max: max_op_pll_multiplier check: %u\n",
433 		more_mul_max);
434 	/* Don't go above max pll op frequency. */
435 	more_mul_max =
436 		min_t(uint32_t,
437 		      more_mul_max,
438 		      op_lim_fr->max_pll_op_clk_freq_hz
439 		      / (pll->ext_clk_freq_hz /
440 			 op_pll_fr->pre_pll_clk_div * mul));
441 	dev_dbg(dev, "more_mul_max: max_pll_op_clk_freq_hz check: %u\n",
442 		more_mul_max);
443 	/* Don't go above the division capability of op sys clock divider. */
444 	more_mul_max = min(more_mul_max,
445 			   op_lim_bk->max_sys_clk_div * op_pll_fr->pre_pll_clk_div
446 			   / div);
447 	dev_dbg(dev, "more_mul_max: max_op_sys_clk_div check: %u\n",
448 		more_mul_max);
449 	/* Ensure we won't go above max_pll_multiplier. */
450 	more_mul_max = min(more_mul_max, op_lim_fr->max_pll_multiplier / mul);
451 	dev_dbg(dev, "more_mul_max: min_pll_multiplier check: %u\n",
452 		more_mul_max);
453 
454 	/* Ensure we won't go below min_pll_op_clk_freq_hz. */
455 	more_mul_min = DIV_ROUND_UP(op_lim_fr->min_pll_op_clk_freq_hz,
456 				    pll->ext_clk_freq_hz /
457 				    op_pll_fr->pre_pll_clk_div * mul);
458 	dev_dbg(dev, "more_mul_min: min_op_pll_op_clk_freq_hz check: %u\n",
459 		more_mul_min);
460 	/* Ensure we won't go below min_pll_multiplier. */
461 	more_mul_min = max(more_mul_min,
462 			   DIV_ROUND_UP(op_lim_fr->min_pll_multiplier, mul));
463 	dev_dbg(dev, "more_mul_min: min_op_pll_multiplier check: %u\n",
464 		more_mul_min);
465 
466 	if (more_mul_min > more_mul_max) {
467 		dev_dbg(dev,
468 			"unable to compute more_mul_min and more_mul_max\n");
469 		return -EINVAL;
470 	}
471 
472 	more_mul_factor = lcm(div, op_pll_fr->pre_pll_clk_div) / div;
473 	dev_dbg(dev, "more_mul_factor: %u\n", more_mul_factor);
474 	more_mul_factor = lcm(more_mul_factor, op_lim_bk->min_sys_clk_div);
475 	dev_dbg(dev, "more_mul_factor: min_op_sys_clk_div: %d\n",
476 		more_mul_factor);
477 	i = roundup(more_mul_min, more_mul_factor);
478 	if (!is_one_or_even(i))
479 		i <<= 1;
480 
481 	dev_dbg(dev, "final more_mul: %u\n", i);
482 	if (i > more_mul_max) {
483 		dev_dbg(dev, "final more_mul is bad, max %u\n", more_mul_max);
484 		return -EINVAL;
485 	}
486 
487 	op_pll_fr->pll_multiplier = mul * i;
488 	op_pll_bk->sys_clk_div = div * i / op_pll_fr->pre_pll_clk_div;
489 	dev_dbg(dev, "op_sys_clk_div: %u\n", op_pll_bk->sys_clk_div);
490 
491 	op_pll_fr->pll_ip_clk_freq_hz = pll->ext_clk_freq_hz
492 		/ op_pll_fr->pre_pll_clk_div;
493 
494 	op_pll_fr->pll_op_clk_freq_hz = op_pll_fr->pll_ip_clk_freq_hz
495 		* op_pll_fr->pll_multiplier;
496 
497 	if (pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL)
498 		op_pll_bk->pix_clk_div = pll->bits_per_pixel
499 			* pll->op_lanes * phy_const
500 			/ PHY_CONST_DIV / pll->csi2.lanes / l;
501 	else
502 		op_pll_bk->pix_clk_div =
503 			pll->bits_per_pixel * phy_const / PHY_CONST_DIV / l;
504 
505 	op_pll_bk->pix_clk_freq_hz =
506 		op_pll_bk->sys_clk_freq_hz / op_pll_bk->pix_clk_div;
507 
508 	dev_dbg(dev, "op_pix_clk_div: %u\n", op_pll_bk->pix_clk_div);
509 
510 	return 0;
511 }
512 
513 int ccs_pll_calculate(struct device *dev, const struct ccs_pll_limits *lim,
514 		      struct ccs_pll *pll)
515 {
516 	const struct ccs_pll_branch_limits_fr *op_lim_fr = &lim->vt_fr;
517 	const struct ccs_pll_branch_limits_bk *op_lim_bk = &lim->op_bk;
518 	struct ccs_pll_branch_fr *op_pll_fr = &pll->vt_fr;
519 	struct ccs_pll_branch_bk *op_pll_bk = &pll->op_bk;
520 	bool cphy = pll->bus_type == CCS_PLL_BUS_TYPE_CSI2_CPHY;
521 	uint32_t phy_const = cphy ? CPHY_CONST : DPHY_CONST;
522 	uint16_t min_op_pre_pll_clk_div;
523 	uint16_t max_op_pre_pll_clk_div;
524 	uint32_t mul, div;
525 	uint32_t l = (!pll->op_bits_per_lane ||
526 		      pll->op_bits_per_lane >= pll->bits_per_pixel) ? 1 : 2;
527 	uint32_t i;
528 	int rval = -EINVAL;
529 
530 	if (!(pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL)) {
531 		pll->op_lanes = 1;
532 		pll->vt_lanes = 1;
533 	}
534 
535 	if (!pll->op_lanes || !pll->vt_lanes || !pll->bits_per_pixel ||
536 	    !pll->ext_clk_freq_hz || !pll->link_freq || !pll->scale_m ||
537 	    !op_lim_fr->min_pll_ip_clk_freq_hz ||
538 	    !op_lim_fr->max_pll_ip_clk_freq_hz ||
539 	    !op_lim_fr->min_pll_op_clk_freq_hz ||
540 	    !op_lim_fr->max_pll_op_clk_freq_hz ||
541 	    !op_lim_bk->max_sys_clk_div || !op_lim_fr->max_pll_multiplier)
542 		return -EINVAL;
543 
544 	/*
545 	 * Make sure op_pix_clk_div will be integer --- unless flexible
546 	 * op_pix_clk_div is supported
547 	 */
548 	if (!(pll->flags & CCS_PLL_FLAG_FLEXIBLE_OP_PIX_CLK_DIV) &&
549 	    (pll->bits_per_pixel * pll->op_lanes) % (pll->csi2.lanes * l)) {
550 		dev_dbg(dev, "op_pix_clk_div not an integer (bpp %u, op lanes %u, lanes %u, l %u)\n",
551 			pll->bits_per_pixel, pll->op_lanes, pll->csi2.lanes, l);
552 		return -EINVAL;
553 	}
554 
555 	dev_dbg(dev, "vt_lanes: %u\n", pll->vt_lanes);
556 	dev_dbg(dev, "op_lanes: %u\n", pll->op_lanes);
557 
558 	if (pll->flags & CCS_PLL_FLAG_NO_OP_CLOCKS) {
559 		/*
560 		 * If there's no OP PLL at all, use the VT values
561 		 * instead. The OP values are ignored for the rest of
562 		 * the PLL calculation.
563 		 */
564 		op_lim_fr = &lim->vt_fr;
565 		op_lim_bk = &lim->vt_bk;
566 		op_pll_bk = &pll->vt_bk;
567 	}
568 
569 	dev_dbg(dev, "binning: %ux%u\n", pll->binning_horizontal,
570 		pll->binning_vertical);
571 
572 	switch (pll->bus_type) {
573 	case CCS_PLL_BUS_TYPE_CSI2_DPHY:
574 		/* CSI transfers 2 bits per clock per lane; thus times 2 */
575 		op_pll_bk->sys_clk_freq_hz = pll->link_freq * 2
576 			* (pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL ?
577 			   1 : pll->csi2.lanes);
578 		break;
579 	case CCS_PLL_BUS_TYPE_CSI2_CPHY:
580 		op_pll_bk->sys_clk_freq_hz =
581 			pll->link_freq
582 			* (pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL ?
583 			   1 : pll->csi2.lanes);
584 		break;
585 	default:
586 		return -EINVAL;
587 	}
588 
589 	pll->pixel_rate_csi =
590 		div_u64((uint64_t)op_pll_bk->sys_clk_freq_hz
591 			* (pll->flags & CCS_PLL_FLAG_LANE_SPEED_MODEL ?
592 			   pll->csi2.lanes : 1) * PHY_CONST_DIV,
593 			phy_const * pll->bits_per_pixel * l);
594 
595 	/* Figure out limits for OP pre-pll divider based on extclk */
596 	dev_dbg(dev, "min / max op_pre_pll_clk_div: %u / %u\n",
597 		op_lim_fr->min_pre_pll_clk_div, op_lim_fr->max_pre_pll_clk_div);
598 	max_op_pre_pll_clk_div =
599 		min_t(uint16_t, op_lim_fr->max_pre_pll_clk_div,
600 		      clk_div_even(pll->ext_clk_freq_hz /
601 				   op_lim_fr->min_pll_ip_clk_freq_hz));
602 	min_op_pre_pll_clk_div =
603 		max_t(uint16_t, op_lim_fr->min_pre_pll_clk_div,
604 		      clk_div_even_up(
605 			      DIV_ROUND_UP(pll->ext_clk_freq_hz,
606 					   op_lim_fr->max_pll_ip_clk_freq_hz)));
607 	dev_dbg(dev, "pre-pll check: min / max op_pre_pll_clk_div: %u / %u\n",
608 		min_op_pre_pll_clk_div, max_op_pre_pll_clk_div);
609 
610 	i = gcd(op_pll_bk->sys_clk_freq_hz, pll->ext_clk_freq_hz);
611 	mul = op_pll_bk->sys_clk_freq_hz / i;
612 	div = pll->ext_clk_freq_hz / i;
613 	dev_dbg(dev, "mul %u / div %u\n", mul, div);
614 
615 	min_op_pre_pll_clk_div =
616 		max_t(uint16_t, min_op_pre_pll_clk_div,
617 		      clk_div_even_up(
618 			      mul /
619 			      one_or_more(
620 				      DIV_ROUND_UP(op_lim_fr->max_pll_op_clk_freq_hz,
621 						   pll->ext_clk_freq_hz))));
622 	dev_dbg(dev, "pll_op check: min / max op_pre_pll_clk_div: %u / %u\n",
623 		min_op_pre_pll_clk_div, max_op_pre_pll_clk_div);
624 
625 	for (op_pll_fr->pre_pll_clk_div = min_op_pre_pll_clk_div;
626 	     op_pll_fr->pre_pll_clk_div <= max_op_pre_pll_clk_div;
627 	     op_pll_fr->pre_pll_clk_div +=
628 		     (pll->flags & CCS_PLL_FLAG_EXT_IP_PLL_DIVIDER) ? 1 :
629 		     2 - (op_pll_fr->pre_pll_clk_div & 1)) {
630 		rval = ccs_pll_calculate_op(dev, lim, op_lim_fr, op_lim_bk, pll,
631 					    op_pll_fr, op_pll_bk, mul, div, l,
632 					    cphy, phy_const);
633 		if (rval)
634 			continue;
635 
636 		rval = check_fr_bounds(dev, lim, pll, PLL_VT);
637 		if (rval)
638 			continue;
639 
640 		rval = check_bk_bounds(dev, lim, pll, PLL_OP);
641 		if (rval)
642 			continue;
643 
644 		ccs_pll_calculate_vt(dev, lim, op_lim_bk, pll, op_pll_fr,
645 				     op_pll_bk, cphy, phy_const);
646 
647 		rval = check_bk_bounds(dev, lim, pll, PLL_VT);
648 		if (rval)
649 			continue;
650 		rval = check_ext_bounds(dev, pll);
651 		if (rval)
652 			continue;
653 
654 		print_pll(dev, pll);
655 
656 		return 0;
657 	}
658 
659 	dev_dbg(dev, "unable to compute pre_pll divisor\n");
660 
661 	return rval;
662 }
663 EXPORT_SYMBOL_GPL(ccs_pll_calculate);
664 
665 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
666 MODULE_DESCRIPTION("Generic MIPI CCS/SMIA/SMIA++ PLL calculator");
667 MODULE_LICENSE("GPL v2");
668