1 /*
2  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  */
10 
11 #include <linux/clk-provider.h>
12 #include <linux/clkdev.h>
13 #include <linux/clk/at91_pmc.h>
14 #include <linux/of.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/regmap.h>
17 
18 #include "pmc.h"
19 
20 #define USB_SOURCE_MAX		2
21 
22 #define SAM9X5_USB_DIV_SHIFT	8
23 #define SAM9X5_USB_MAX_DIV	0xf
24 
25 #define RM9200_USB_DIV_SHIFT	28
26 #define RM9200_USB_DIV_TAB_SIZE	4
27 
28 struct at91sam9x5_clk_usb {
29 	struct clk_hw hw;
30 	struct regmap *regmap;
31 };
32 
33 #define to_at91sam9x5_clk_usb(hw) \
34 	container_of(hw, struct at91sam9x5_clk_usb, hw)
35 
36 struct at91rm9200_clk_usb {
37 	struct clk_hw hw;
38 	struct regmap *regmap;
39 	u32 divisors[4];
40 };
41 
42 #define to_at91rm9200_clk_usb(hw) \
43 	container_of(hw, struct at91rm9200_clk_usb, hw)
44 
at91sam9x5_clk_usb_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)45 static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
46 						    unsigned long parent_rate)
47 {
48 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
49 	unsigned int usbr;
50 	u8 usbdiv;
51 
52 	regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
53 	usbdiv = (usbr & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
54 
55 	return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
56 }
57 
at91sam9x5_clk_usb_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)58 static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
59 					     struct clk_rate_request *req)
60 {
61 	struct clk_hw *parent;
62 	long best_rate = -EINVAL;
63 	unsigned long tmp_rate;
64 	int best_diff = -1;
65 	int tmp_diff;
66 	int i;
67 
68 	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
69 		int div;
70 
71 		parent = clk_hw_get_parent_by_index(hw, i);
72 		if (!parent)
73 			continue;
74 
75 		for (div = 1; div < SAM9X5_USB_MAX_DIV + 2; div++) {
76 			unsigned long tmp_parent_rate;
77 
78 			tmp_parent_rate = req->rate * div;
79 			tmp_parent_rate = clk_hw_round_rate(parent,
80 							   tmp_parent_rate);
81 			tmp_rate = DIV_ROUND_CLOSEST(tmp_parent_rate, div);
82 			if (tmp_rate < req->rate)
83 				tmp_diff = req->rate - tmp_rate;
84 			else
85 				tmp_diff = tmp_rate - req->rate;
86 
87 			if (best_diff < 0 || best_diff > tmp_diff) {
88 				best_rate = tmp_rate;
89 				best_diff = tmp_diff;
90 				req->best_parent_rate = tmp_parent_rate;
91 				req->best_parent_hw = parent;
92 			}
93 
94 			if (!best_diff || tmp_rate < req->rate)
95 				break;
96 		}
97 
98 		if (!best_diff)
99 			break;
100 	}
101 
102 	if (best_rate < 0)
103 		return best_rate;
104 
105 	req->rate = best_rate;
106 	return 0;
107 }
108 
at91sam9x5_clk_usb_set_parent(struct clk_hw * hw,u8 index)109 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
110 {
111 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
112 
113 	if (index > 1)
114 		return -EINVAL;
115 
116 	regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS,
117 			   index ? AT91_PMC_USBS : 0);
118 
119 	return 0;
120 }
121 
at91sam9x5_clk_usb_get_parent(struct clk_hw * hw)122 static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
123 {
124 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
125 	unsigned int usbr;
126 
127 	regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
128 
129 	return usbr & AT91_PMC_USBS;
130 }
131 
at91sam9x5_clk_usb_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)132 static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
133 				       unsigned long parent_rate)
134 {
135 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
136 	unsigned long div;
137 
138 	if (!rate)
139 		return -EINVAL;
140 
141 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
142 	if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
143 		return -EINVAL;
144 
145 	regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_OHCIUSBDIV,
146 			   (div - 1) << SAM9X5_USB_DIV_SHIFT);
147 
148 	return 0;
149 }
150 
151 static const struct clk_ops at91sam9x5_usb_ops = {
152 	.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
153 	.determine_rate = at91sam9x5_clk_usb_determine_rate,
154 	.get_parent = at91sam9x5_clk_usb_get_parent,
155 	.set_parent = at91sam9x5_clk_usb_set_parent,
156 	.set_rate = at91sam9x5_clk_usb_set_rate,
157 };
158 
at91sam9n12_clk_usb_enable(struct clk_hw * hw)159 static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
160 {
161 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
162 
163 	regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS,
164 			   AT91_PMC_USBS);
165 
166 	return 0;
167 }
168 
at91sam9n12_clk_usb_disable(struct clk_hw * hw)169 static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
170 {
171 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
172 
173 	regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS, 0);
174 }
175 
at91sam9n12_clk_usb_is_enabled(struct clk_hw * hw)176 static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
177 {
178 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
179 	unsigned int usbr;
180 
181 	regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
182 
183 	return usbr & AT91_PMC_USBS;
184 }
185 
186 static const struct clk_ops at91sam9n12_usb_ops = {
187 	.enable = at91sam9n12_clk_usb_enable,
188 	.disable = at91sam9n12_clk_usb_disable,
189 	.is_enabled = at91sam9n12_clk_usb_is_enabled,
190 	.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
191 	.determine_rate = at91sam9x5_clk_usb_determine_rate,
192 	.set_rate = at91sam9x5_clk_usb_set_rate,
193 };
194 
195 static struct clk_hw * __init
at91sam9x5_clk_register_usb(struct regmap * regmap,const char * name,const char ** parent_names,u8 num_parents)196 at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
197 			    const char **parent_names, u8 num_parents)
198 {
199 	struct at91sam9x5_clk_usb *usb;
200 	struct clk_hw *hw;
201 	struct clk_init_data init;
202 	int ret;
203 
204 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
205 	if (!usb)
206 		return ERR_PTR(-ENOMEM);
207 
208 	init.name = name;
209 	init.ops = &at91sam9x5_usb_ops;
210 	init.parent_names = parent_names;
211 	init.num_parents = num_parents;
212 	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
213 		     CLK_SET_RATE_PARENT;
214 
215 	usb->hw.init = &init;
216 	usb->regmap = regmap;
217 
218 	hw = &usb->hw;
219 	ret = clk_hw_register(NULL, &usb->hw);
220 	if (ret) {
221 		kfree(usb);
222 		hw = ERR_PTR(ret);
223 	}
224 
225 	return hw;
226 }
227 
228 static struct clk_hw * __init
at91sam9n12_clk_register_usb(struct regmap * regmap,const char * name,const char * parent_name)229 at91sam9n12_clk_register_usb(struct regmap *regmap, const char *name,
230 			     const char *parent_name)
231 {
232 	struct at91sam9x5_clk_usb *usb;
233 	struct clk_hw *hw;
234 	struct clk_init_data init;
235 	int ret;
236 
237 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
238 	if (!usb)
239 		return ERR_PTR(-ENOMEM);
240 
241 	init.name = name;
242 	init.ops = &at91sam9n12_usb_ops;
243 	init.parent_names = &parent_name;
244 	init.num_parents = 1;
245 	init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
246 
247 	usb->hw.init = &init;
248 	usb->regmap = regmap;
249 
250 	hw = &usb->hw;
251 	ret = clk_hw_register(NULL, &usb->hw);
252 	if (ret) {
253 		kfree(usb);
254 		hw = ERR_PTR(ret);
255 	}
256 
257 	return hw;
258 }
259 
at91rm9200_clk_usb_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)260 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
261 						    unsigned long parent_rate)
262 {
263 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
264 	unsigned int pllbr;
265 	u8 usbdiv;
266 
267 	regmap_read(usb->regmap, AT91_CKGR_PLLBR, &pllbr);
268 
269 	usbdiv = (pllbr & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
270 	if (usb->divisors[usbdiv])
271 		return parent_rate / usb->divisors[usbdiv];
272 
273 	return 0;
274 }
275 
at91rm9200_clk_usb_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)276 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
277 					  unsigned long *parent_rate)
278 {
279 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
280 	struct clk_hw *parent = clk_hw_get_parent(hw);
281 	unsigned long bestrate = 0;
282 	int bestdiff = -1;
283 	unsigned long tmprate;
284 	int tmpdiff;
285 	int i = 0;
286 
287 	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
288 		unsigned long tmp_parent_rate;
289 
290 		if (!usb->divisors[i])
291 			continue;
292 
293 		tmp_parent_rate = rate * usb->divisors[i];
294 		tmp_parent_rate = clk_hw_round_rate(parent, tmp_parent_rate);
295 		tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
296 		if (tmprate < rate)
297 			tmpdiff = rate - tmprate;
298 		else
299 			tmpdiff = tmprate - rate;
300 
301 		if (bestdiff < 0 || bestdiff > tmpdiff) {
302 			bestrate = tmprate;
303 			bestdiff = tmpdiff;
304 			*parent_rate = tmp_parent_rate;
305 		}
306 
307 		if (!bestdiff)
308 			break;
309 	}
310 
311 	return bestrate;
312 }
313 
at91rm9200_clk_usb_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)314 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
315 				       unsigned long parent_rate)
316 {
317 	int i;
318 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
319 	unsigned long div;
320 
321 	if (!rate)
322 		return -EINVAL;
323 
324 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
325 
326 	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
327 		if (usb->divisors[i] == div) {
328 			regmap_update_bits(usb->regmap, AT91_CKGR_PLLBR,
329 					   AT91_PMC_USBDIV,
330 					   i << RM9200_USB_DIV_SHIFT);
331 
332 			return 0;
333 		}
334 	}
335 
336 	return -EINVAL;
337 }
338 
339 static const struct clk_ops at91rm9200_usb_ops = {
340 	.recalc_rate = at91rm9200_clk_usb_recalc_rate,
341 	.round_rate = at91rm9200_clk_usb_round_rate,
342 	.set_rate = at91rm9200_clk_usb_set_rate,
343 };
344 
345 static struct clk_hw * __init
at91rm9200_clk_register_usb(struct regmap * regmap,const char * name,const char * parent_name,const u32 * divisors)346 at91rm9200_clk_register_usb(struct regmap *regmap, const char *name,
347 			    const char *parent_name, const u32 *divisors)
348 {
349 	struct at91rm9200_clk_usb *usb;
350 	struct clk_hw *hw;
351 	struct clk_init_data init;
352 	int ret;
353 
354 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
355 	if (!usb)
356 		return ERR_PTR(-ENOMEM);
357 
358 	init.name = name;
359 	init.ops = &at91rm9200_usb_ops;
360 	init.parent_names = &parent_name;
361 	init.num_parents = 1;
362 	init.flags = CLK_SET_RATE_PARENT;
363 
364 	usb->hw.init = &init;
365 	usb->regmap = regmap;
366 	memcpy(usb->divisors, divisors, sizeof(usb->divisors));
367 
368 	hw = &usb->hw;
369 	ret = clk_hw_register(NULL, &usb->hw);
370 	if (ret) {
371 		kfree(usb);
372 		hw = ERR_PTR(ret);
373 	}
374 
375 	return hw;
376 }
377 
of_at91sam9x5_clk_usb_setup(struct device_node * np)378 static void __init of_at91sam9x5_clk_usb_setup(struct device_node *np)
379 {
380 	struct clk_hw *hw;
381 	unsigned int num_parents;
382 	const char *parent_names[USB_SOURCE_MAX];
383 	const char *name = np->name;
384 	struct regmap *regmap;
385 
386 	num_parents = of_clk_get_parent_count(np);
387 	if (num_parents == 0 || num_parents > USB_SOURCE_MAX)
388 		return;
389 
390 	of_clk_parent_fill(np, parent_names, num_parents);
391 
392 	of_property_read_string(np, "clock-output-names", &name);
393 
394 	regmap = syscon_node_to_regmap(of_get_parent(np));
395 	if (IS_ERR(regmap))
396 		return;
397 
398 	hw = at91sam9x5_clk_register_usb(regmap, name, parent_names,
399 					 num_parents);
400 	if (IS_ERR(hw))
401 		return;
402 
403 	of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
404 }
405 CLK_OF_DECLARE(at91sam9x5_clk_usb, "atmel,at91sam9x5-clk-usb",
406 	       of_at91sam9x5_clk_usb_setup);
407 
of_at91sam9n12_clk_usb_setup(struct device_node * np)408 static void __init of_at91sam9n12_clk_usb_setup(struct device_node *np)
409 {
410 	struct clk_hw *hw;
411 	const char *parent_name;
412 	const char *name = np->name;
413 	struct regmap *regmap;
414 
415 	parent_name = of_clk_get_parent_name(np, 0);
416 	if (!parent_name)
417 		return;
418 
419 	of_property_read_string(np, "clock-output-names", &name);
420 
421 	regmap = syscon_node_to_regmap(of_get_parent(np));
422 	if (IS_ERR(regmap))
423 		return;
424 
425 	hw = at91sam9n12_clk_register_usb(regmap, name, parent_name);
426 	if (IS_ERR(hw))
427 		return;
428 
429 	of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
430 }
431 CLK_OF_DECLARE(at91sam9n12_clk_usb, "atmel,at91sam9n12-clk-usb",
432 	       of_at91sam9n12_clk_usb_setup);
433 
of_at91rm9200_clk_usb_setup(struct device_node * np)434 static void __init of_at91rm9200_clk_usb_setup(struct device_node *np)
435 {
436 	struct clk_hw *hw;
437 	const char *parent_name;
438 	const char *name = np->name;
439 	u32 divisors[4] = {0, 0, 0, 0};
440 	struct regmap *regmap;
441 
442 	parent_name = of_clk_get_parent_name(np, 0);
443 	if (!parent_name)
444 		return;
445 
446 	of_property_read_u32_array(np, "atmel,clk-divisors", divisors, 4);
447 	if (!divisors[0])
448 		return;
449 
450 	of_property_read_string(np, "clock-output-names", &name);
451 
452 	regmap = syscon_node_to_regmap(of_get_parent(np));
453 	if (IS_ERR(regmap))
454 		return;
455 	hw = at91rm9200_clk_register_usb(regmap, name, parent_name, divisors);
456 	if (IS_ERR(hw))
457 		return;
458 
459 	of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
460 }
461 CLK_OF_DECLARE(at91rm9200_clk_usb, "atmel,at91rm9200-clk-usb",
462 	       of_at91rm9200_clk_usb_setup);
463