xref: /openbmc/linux/drivers/clk/at91/clk-usb.c (revision 3a83e4e6)
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 	u8 num_parents;
29 };
30 
31 #define to_at91sam9x5_clk_usb(hw) \
32 	container_of(hw, struct at91sam9x5_clk_usb, hw)
33 
34 struct at91rm9200_clk_usb {
35 	struct clk_hw hw;
36 	struct regmap *regmap;
37 	u32 divisors[4];
38 };
39 
40 #define to_at91rm9200_clk_usb(hw) \
41 	container_of(hw, struct at91rm9200_clk_usb, hw)
42 
43 static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
44 						    unsigned long parent_rate)
45 {
46 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
47 	unsigned int usbr;
48 	u8 usbdiv;
49 
50 	regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
51 	usbdiv = (usbr & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
52 
53 	return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
54 }
55 
56 static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
57 					     struct clk_rate_request *req)
58 {
59 	struct clk_hw *parent;
60 	long best_rate = -EINVAL;
61 	unsigned long tmp_rate;
62 	int best_diff = -1;
63 	int tmp_diff;
64 	int i;
65 
66 	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
67 		int div;
68 
69 		parent = clk_hw_get_parent_by_index(hw, i);
70 		if (!parent)
71 			continue;
72 
73 		for (div = 1; div < SAM9X5_USB_MAX_DIV + 2; div++) {
74 			unsigned long tmp_parent_rate;
75 
76 			tmp_parent_rate = req->rate * div;
77 			tmp_parent_rate = clk_hw_round_rate(parent,
78 							   tmp_parent_rate);
79 			if (!tmp_parent_rate)
80 				continue;
81 
82 			tmp_rate = DIV_ROUND_CLOSEST(tmp_parent_rate, div);
83 			if (tmp_rate < req->rate)
84 				tmp_diff = req->rate - tmp_rate;
85 			else
86 				tmp_diff = tmp_rate - req->rate;
87 
88 			if (best_diff < 0 || best_diff > tmp_diff) {
89 				best_rate = tmp_rate;
90 				best_diff = tmp_diff;
91 				req->best_parent_rate = tmp_parent_rate;
92 				req->best_parent_hw = parent;
93 			}
94 
95 			if (!best_diff || tmp_rate < req->rate)
96 				break;
97 		}
98 
99 		if (!best_diff)
100 			break;
101 	}
102 
103 	if (best_rate < 0)
104 		return best_rate;
105 
106 	req->rate = best_rate;
107 	return 0;
108 }
109 
110 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
111 {
112 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
113 
114 	if (index >= usb->num_parents)
115 		return -EINVAL;
116 
117 	regmap_update_bits(usb->regmap, AT91_PMC_USB, usb->usbs_mask, index);
118 
119 	return 0;
120 }
121 
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 & usb->usbs_mask;
130 }
131 
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 
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 
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 
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
196 _at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
197 			     const char **parent_names, u8 num_parents,
198 			     u32 usbs_mask)
199 {
200 	struct at91sam9x5_clk_usb *usb;
201 	struct clk_hw *hw;
202 	struct clk_init_data init;
203 	int ret;
204 
205 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
206 	if (!usb)
207 		return ERR_PTR(-ENOMEM);
208 
209 	init.name = name;
210 	init.ops = &at91sam9x5_usb_ops;
211 	init.parent_names = parent_names;
212 	init.num_parents = num_parents;
213 	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
214 		     CLK_SET_RATE_PARENT;
215 
216 	usb->hw.init = &init;
217 	usb->regmap = regmap;
218 	usb->usbs_mask = usbs_mask;
219 	usb->num_parents = num_parents;
220 
221 	hw = &usb->hw;
222 	ret = clk_hw_register(NULL, &usb->hw);
223 	if (ret) {
224 		kfree(usb);
225 		hw = ERR_PTR(ret);
226 	}
227 
228 	return hw;
229 }
230 
231 struct clk_hw * __init
232 at91sam9x5_clk_register_usb(struct regmap *regmap, const char *name,
233 			    const char **parent_names, u8 num_parents)
234 {
235 	return _at91sam9x5_clk_register_usb(regmap, name, parent_names,
236 					    num_parents, SAM9X5_USBS_MASK);
237 }
238 
239 struct clk_hw * __init
240 sam9x60_clk_register_usb(struct regmap *regmap, const char *name,
241 			 const char **parent_names, u8 num_parents)
242 {
243 	return _at91sam9x5_clk_register_usb(regmap, name, parent_names,
244 					    num_parents, SAM9X60_USBS_MASK);
245 }
246 
247 struct clk_hw * __init
248 at91sam9n12_clk_register_usb(struct regmap *regmap, const char *name,
249 			     const char *parent_name)
250 {
251 	struct at91sam9x5_clk_usb *usb;
252 	struct clk_hw *hw;
253 	struct clk_init_data init;
254 	int ret;
255 
256 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
257 	if (!usb)
258 		return ERR_PTR(-ENOMEM);
259 
260 	init.name = name;
261 	init.ops = &at91sam9n12_usb_ops;
262 	init.parent_names = &parent_name;
263 	init.num_parents = 1;
264 	init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
265 
266 	usb->hw.init = &init;
267 	usb->regmap = regmap;
268 
269 	hw = &usb->hw;
270 	ret = clk_hw_register(NULL, &usb->hw);
271 	if (ret) {
272 		kfree(usb);
273 		hw = ERR_PTR(ret);
274 	}
275 
276 	return hw;
277 }
278 
279 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
280 						    unsigned long parent_rate)
281 {
282 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
283 	unsigned int pllbr;
284 	u8 usbdiv;
285 
286 	regmap_read(usb->regmap, AT91_CKGR_PLLBR, &pllbr);
287 
288 	usbdiv = (pllbr & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
289 	if (usb->divisors[usbdiv])
290 		return parent_rate / usb->divisors[usbdiv];
291 
292 	return 0;
293 }
294 
295 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
296 					  unsigned long *parent_rate)
297 {
298 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
299 	struct clk_hw *parent = clk_hw_get_parent(hw);
300 	unsigned long bestrate = 0;
301 	int bestdiff = -1;
302 	unsigned long tmprate;
303 	int tmpdiff;
304 	int i = 0;
305 
306 	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
307 		unsigned long tmp_parent_rate;
308 
309 		if (!usb->divisors[i])
310 			continue;
311 
312 		tmp_parent_rate = rate * usb->divisors[i];
313 		tmp_parent_rate = clk_hw_round_rate(parent, tmp_parent_rate);
314 		tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
315 		if (tmprate < rate)
316 			tmpdiff = rate - tmprate;
317 		else
318 			tmpdiff = tmprate - rate;
319 
320 		if (bestdiff < 0 || bestdiff > tmpdiff) {
321 			bestrate = tmprate;
322 			bestdiff = tmpdiff;
323 			*parent_rate = tmp_parent_rate;
324 		}
325 
326 		if (!bestdiff)
327 			break;
328 	}
329 
330 	return bestrate;
331 }
332 
333 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
334 				       unsigned long parent_rate)
335 {
336 	int i;
337 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
338 	unsigned long div;
339 
340 	if (!rate)
341 		return -EINVAL;
342 
343 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
344 
345 	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
346 		if (usb->divisors[i] == div) {
347 			regmap_update_bits(usb->regmap, AT91_CKGR_PLLBR,
348 					   AT91_PMC_USBDIV,
349 					   i << RM9200_USB_DIV_SHIFT);
350 
351 			return 0;
352 		}
353 	}
354 
355 	return -EINVAL;
356 }
357 
358 static const struct clk_ops at91rm9200_usb_ops = {
359 	.recalc_rate = at91rm9200_clk_usb_recalc_rate,
360 	.round_rate = at91rm9200_clk_usb_round_rate,
361 	.set_rate = at91rm9200_clk_usb_set_rate,
362 };
363 
364 struct clk_hw * __init
365 at91rm9200_clk_register_usb(struct regmap *regmap, const char *name,
366 			    const char *parent_name, const u32 *divisors)
367 {
368 	struct at91rm9200_clk_usb *usb;
369 	struct clk_hw *hw;
370 	struct clk_init_data init;
371 	int ret;
372 
373 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
374 	if (!usb)
375 		return ERR_PTR(-ENOMEM);
376 
377 	init.name = name;
378 	init.ops = &at91rm9200_usb_ops;
379 	init.parent_names = &parent_name;
380 	init.num_parents = 1;
381 	init.flags = CLK_SET_RATE_PARENT;
382 
383 	usb->hw.init = &init;
384 	usb->regmap = regmap;
385 	memcpy(usb->divisors, divisors, sizeof(usb->divisors));
386 
387 	hw = &usb->hw;
388 	ret = clk_hw_register(NULL, &usb->hw);
389 	if (ret) {
390 		kfree(usb);
391 		hw = ERR_PTR(ret);
392 	}
393 
394 	return hw;
395 }
396