xref: /linux/drivers/clk/at91/clk-usb.c (revision af873fcecef567abf8a3468b06dd4e4aab46da6d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/clkdev.h>
8 #include <linux/clk/at91_pmc.h>
9 #include <linux/of.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/regmap.h>
12 
13 #include "pmc.h"
14 
15 #define SAM9X5_USB_DIV_SHIFT	8
16 #define SAM9X5_USB_MAX_DIV	0xf
17 
18 #define RM9200_USB_DIV_SHIFT	28
19 #define RM9200_USB_DIV_TAB_SIZE	4
20 
21 #define SAM9X5_USBS_MASK	GENMASK(0, 0)
22 #define SAM9X60_USBS_MASK	GENMASK(1, 0)
23 
24 struct at91sam9x5_clk_usb {
25 	struct clk_hw hw;
26 	struct regmap *regmap;
27 	u32 usbs_mask;
28 };
29 
30 #define to_at91sam9x5_clk_usb(hw) \
31 	container_of(hw, struct at91sam9x5_clk_usb, hw)
32 
33 struct at91rm9200_clk_usb {
34 	struct clk_hw hw;
35 	struct regmap *regmap;
36 	u32 divisors[4];
37 };
38 
39 #define to_at91rm9200_clk_usb(hw) \
40 	container_of(hw, struct at91rm9200_clk_usb, hw)
41 
42 static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
43 						    unsigned long parent_rate)
44 {
45 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
46 	unsigned int usbr;
47 	u8 usbdiv;
48 
49 	regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
50 	usbdiv = (usbr & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
51 
52 	return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
53 }
54 
55 static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
56 					     struct clk_rate_request *req)
57 {
58 	struct clk_hw *parent;
59 	long best_rate = -EINVAL;
60 	unsigned long tmp_rate;
61 	int best_diff = -1;
62 	int tmp_diff;
63 	int i;
64 
65 	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
66 		int div;
67 
68 		parent = clk_hw_get_parent_by_index(hw, i);
69 		if (!parent)
70 			continue;
71 
72 		for (div = 1; div < SAM9X5_USB_MAX_DIV + 2; div++) {
73 			unsigned long tmp_parent_rate;
74 
75 			tmp_parent_rate = req->rate * div;
76 			tmp_parent_rate = clk_hw_round_rate(parent,
77 							   tmp_parent_rate);
78 			tmp_rate = DIV_ROUND_CLOSEST(tmp_parent_rate, div);
79 			if (tmp_rate < req->rate)
80 				tmp_diff = req->rate - tmp_rate;
81 			else
82 				tmp_diff = tmp_rate - req->rate;
83 
84 			if (best_diff < 0 || best_diff > tmp_diff) {
85 				best_rate = tmp_rate;
86 				best_diff = tmp_diff;
87 				req->best_parent_rate = tmp_parent_rate;
88 				req->best_parent_hw = parent;
89 			}
90 
91 			if (!best_diff || tmp_rate < req->rate)
92 				break;
93 		}
94 
95 		if (!best_diff)
96 			break;
97 	}
98 
99 	if (best_rate < 0)
100 		return best_rate;
101 
102 	req->rate = best_rate;
103 	return 0;
104 }
105 
106 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
107 {
108 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
109 
110 	if (index > 1)
111 		return -EINVAL;
112 
113 	regmap_update_bits(usb->regmap, AT91_PMC_USB, usb->usbs_mask, index);
114 
115 	return 0;
116 }
117 
118 static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
119 {
120 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
121 	unsigned int usbr;
122 
123 	regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
124 
125 	return usbr & usb->usbs_mask;
126 }
127 
128 static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
129 				       unsigned long parent_rate)
130 {
131 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
132 	unsigned long div;
133 
134 	if (!rate)
135 		return -EINVAL;
136 
137 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
138 	if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
139 		return -EINVAL;
140 
141 	regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_OHCIUSBDIV,
142 			   (div - 1) << SAM9X5_USB_DIV_SHIFT);
143 
144 	return 0;
145 }
146 
147 static const struct clk_ops at91sam9x5_usb_ops = {
148 	.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
149 	.determine_rate = at91sam9x5_clk_usb_determine_rate,
150 	.get_parent = at91sam9x5_clk_usb_get_parent,
151 	.set_parent = at91sam9x5_clk_usb_set_parent,
152 	.set_rate = at91sam9x5_clk_usb_set_rate,
153 };
154 
155 static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
156 {
157 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
158 
159 	regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS,
160 			   AT91_PMC_USBS);
161 
162 	return 0;
163 }
164 
165 static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
166 {
167 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
168 
169 	regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_USBS, 0);
170 }
171 
172 static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
173 {
174 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
175 	unsigned int usbr;
176 
177 	regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
178 
179 	return usbr & AT91_PMC_USBS;
180 }
181 
182 static const struct clk_ops at91sam9n12_usb_ops = {
183 	.enable = at91sam9n12_clk_usb_enable,
184 	.disable = at91sam9n12_clk_usb_disable,
185 	.is_enabled = at91sam9n12_clk_usb_is_enabled,
186 	.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
187 	.determine_rate = at91sam9x5_clk_usb_determine_rate,
188 	.set_rate = at91sam9x5_clk_usb_set_rate,
189 };
190 
191 static struct clk_hw * __init
192 _at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
193 			     const char **parent_names, u8 num_parents,
194 			     u32 usbs_mask)
195 {
196 	struct at91sam9x5_clk_usb *usb;
197 	struct clk_hw *hw;
198 	struct clk_init_data init;
199 	int ret;
200 
201 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
202 	if (!usb)
203 		return ERR_PTR(-ENOMEM);
204 
205 	init.name = name;
206 	init.ops = &at91sam9x5_usb_ops;
207 	init.parent_names = parent_names;
208 	init.num_parents = num_parents;
209 	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
210 		     CLK_SET_RATE_PARENT;
211 
212 	usb->hw.init = &init;
213 	usb->regmap = regmap;
214 	usb->usbs_mask = SAM9X5_USBS_MASK;
215 
216 	hw = &usb->hw;
217 	ret = clk_hw_register(NULL, &usb->hw);
218 	if (ret) {
219 		kfree(usb);
220 		hw = ERR_PTR(ret);
221 	}
222 
223 	return hw;
224 }
225 
226 struct clk_hw * __init
227 at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
228 			    const char **parent_names, u8 num_parents)
229 {
230 	return _at91sam9x5_clk_register_usb(regmap, name, parent_names,
231 					    num_parents, SAM9X5_USBS_MASK);
232 }
233 
234 struct clk_hw * __init
235 sam9x60_clk_register_usb(struct regmap *regmap, const char *name,
236 			 const char **parent_names, u8 num_parents)
237 {
238 	return _at91sam9x5_clk_register_usb(regmap, name, parent_names,
239 					    num_parents, SAM9X60_USBS_MASK);
240 }
241 
242 struct clk_hw * __init
243 at91sam9n12_clk_register_usb(struct regmap *regmap, const char *name,
244 			     const char *parent_name)
245 {
246 	struct at91sam9x5_clk_usb *usb;
247 	struct clk_hw *hw;
248 	struct clk_init_data init;
249 	int ret;
250 
251 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
252 	if (!usb)
253 		return ERR_PTR(-ENOMEM);
254 
255 	init.name = name;
256 	init.ops = &at91sam9n12_usb_ops;
257 	init.parent_names = &parent_name;
258 	init.num_parents = 1;
259 	init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
260 
261 	usb->hw.init = &init;
262 	usb->regmap = regmap;
263 
264 	hw = &usb->hw;
265 	ret = clk_hw_register(NULL, &usb->hw);
266 	if (ret) {
267 		kfree(usb);
268 		hw = ERR_PTR(ret);
269 	}
270 
271 	return hw;
272 }
273 
274 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
275 						    unsigned long parent_rate)
276 {
277 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
278 	unsigned int pllbr;
279 	u8 usbdiv;
280 
281 	regmap_read(usb->regmap, AT91_CKGR_PLLBR, &pllbr);
282 
283 	usbdiv = (pllbr & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
284 	if (usb->divisors[usbdiv])
285 		return parent_rate / usb->divisors[usbdiv];
286 
287 	return 0;
288 }
289 
290 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
291 					  unsigned long *parent_rate)
292 {
293 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
294 	struct clk_hw *parent = clk_hw_get_parent(hw);
295 	unsigned long bestrate = 0;
296 	int bestdiff = -1;
297 	unsigned long tmprate;
298 	int tmpdiff;
299 	int i = 0;
300 
301 	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
302 		unsigned long tmp_parent_rate;
303 
304 		if (!usb->divisors[i])
305 			continue;
306 
307 		tmp_parent_rate = rate * usb->divisors[i];
308 		tmp_parent_rate = clk_hw_round_rate(parent, tmp_parent_rate);
309 		tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
310 		if (tmprate < rate)
311 			tmpdiff = rate - tmprate;
312 		else
313 			tmpdiff = tmprate - rate;
314 
315 		if (bestdiff < 0 || bestdiff > tmpdiff) {
316 			bestrate = tmprate;
317 			bestdiff = tmpdiff;
318 			*parent_rate = tmp_parent_rate;
319 		}
320 
321 		if (!bestdiff)
322 			break;
323 	}
324 
325 	return bestrate;
326 }
327 
328 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
329 				       unsigned long parent_rate)
330 {
331 	int i;
332 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
333 	unsigned long div;
334 
335 	if (!rate)
336 		return -EINVAL;
337 
338 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
339 
340 	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
341 		if (usb->divisors[i] == div) {
342 			regmap_update_bits(usb->regmap, AT91_CKGR_PLLBR,
343 					   AT91_PMC_USBDIV,
344 					   i << RM9200_USB_DIV_SHIFT);
345 
346 			return 0;
347 		}
348 	}
349 
350 	return -EINVAL;
351 }
352 
353 static const struct clk_ops at91rm9200_usb_ops = {
354 	.recalc_rate = at91rm9200_clk_usb_recalc_rate,
355 	.round_rate = at91rm9200_clk_usb_round_rate,
356 	.set_rate = at91rm9200_clk_usb_set_rate,
357 };
358 
359 struct clk_hw * __init
360 at91rm9200_clk_register_usb(struct regmap *regmap, const char *name,
361 			    const char *parent_name, const u32 *divisors)
362 {
363 	struct at91rm9200_clk_usb *usb;
364 	struct clk_hw *hw;
365 	struct clk_init_data init;
366 	int ret;
367 
368 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
369 	if (!usb)
370 		return ERR_PTR(-ENOMEM);
371 
372 	init.name = name;
373 	init.ops = &at91rm9200_usb_ops;
374 	init.parent_names = &parent_name;
375 	init.num_parents = 1;
376 	init.flags = CLK_SET_RATE_PARENT;
377 
378 	usb->hw.init = &init;
379 	usb->regmap = regmap;
380 	memcpy(usb->divisors, divisors, sizeof(usb->divisors));
381 
382 	hw = &usb->hw;
383 	ret = clk_hw_register(NULL, &usb->hw);
384 	if (ret) {
385 		kfree(usb);
386 		hw = ERR_PTR(ret);
387 	}
388 
389 	return hw;
390 }
391