xref: /linux/drivers/clk/at91/clk-usb.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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/of_address.h>
16 #include <linux/io.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 at91_pmc *pmc;
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 at91_pmc *pmc;
39 	u32 divisors[4];
40 };
41 
42 #define to_at91rm9200_clk_usb(hw) \
43 	container_of(hw, struct at91rm9200_clk_usb, hw)
44 
45 static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
46 						    unsigned long parent_rate)
47 {
48 	u32 tmp;
49 	u8 usbdiv;
50 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
51 	struct at91_pmc *pmc = usb->pmc;
52 
53 	tmp = pmc_read(pmc, AT91_PMC_USB);
54 	usbdiv = (tmp & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
55 	return parent_rate / (usbdiv + 1);
56 }
57 
58 static long at91sam9x5_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
59 					  unsigned long *parent_rate)
60 {
61 	unsigned long div;
62 	unsigned long bestrate;
63 	unsigned long tmp;
64 
65 	if (rate >= *parent_rate)
66 		return *parent_rate;
67 
68 	div = *parent_rate / rate;
69 	if (div >= SAM9X5_USB_MAX_DIV)
70 		return *parent_rate / (SAM9X5_USB_MAX_DIV + 1);
71 
72 	bestrate = *parent_rate / div;
73 	tmp = *parent_rate / (div + 1);
74 	if (bestrate - rate > rate - tmp)
75 		bestrate = tmp;
76 
77 	return bestrate;
78 }
79 
80 static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
81 {
82 	u32 tmp;
83 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
84 	struct at91_pmc *pmc = usb->pmc;
85 
86 	if (index > 1)
87 		return -EINVAL;
88 	tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS;
89 	if (index)
90 		tmp |= AT91_PMC_USBS;
91 	pmc_write(pmc, AT91_PMC_USB, tmp);
92 	return 0;
93 }
94 
95 static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
96 {
97 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
98 	struct at91_pmc *pmc = usb->pmc;
99 
100 	return pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS;
101 }
102 
103 static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
104 				       unsigned long parent_rate)
105 {
106 	u32 tmp;
107 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
108 	struct at91_pmc *pmc = usb->pmc;
109 	unsigned long div = parent_rate / rate;
110 
111 	if (parent_rate % rate || div < 1 || div >= SAM9X5_USB_MAX_DIV)
112 		return -EINVAL;
113 
114 	tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV;
115 	tmp |= (div - 1) << SAM9X5_USB_DIV_SHIFT;
116 	pmc_write(pmc, AT91_PMC_USB, tmp);
117 
118 	return 0;
119 }
120 
121 static const struct clk_ops at91sam9x5_usb_ops = {
122 	.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
123 	.round_rate = at91sam9x5_clk_usb_round_rate,
124 	.get_parent = at91sam9x5_clk_usb_get_parent,
125 	.set_parent = at91sam9x5_clk_usb_set_parent,
126 	.set_rate = at91sam9x5_clk_usb_set_rate,
127 };
128 
129 static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
130 {
131 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
132 	struct at91_pmc *pmc = usb->pmc;
133 
134 	pmc_write(pmc, AT91_PMC_USB,
135 		  pmc_read(pmc, AT91_PMC_USB) | AT91_PMC_USBS);
136 	return 0;
137 }
138 
139 static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
140 {
141 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
142 	struct at91_pmc *pmc = usb->pmc;
143 
144 	pmc_write(pmc, AT91_PMC_USB,
145 		  pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS);
146 }
147 
148 static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
149 {
150 	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
151 	struct at91_pmc *pmc = usb->pmc;
152 
153 	return !!(pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS);
154 }
155 
156 static const struct clk_ops at91sam9n12_usb_ops = {
157 	.enable = at91sam9n12_clk_usb_enable,
158 	.disable = at91sam9n12_clk_usb_disable,
159 	.is_enabled = at91sam9n12_clk_usb_is_enabled,
160 	.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
161 	.round_rate = at91sam9x5_clk_usb_round_rate,
162 	.set_rate = at91sam9x5_clk_usb_set_rate,
163 };
164 
165 static struct clk * __init
166 at91sam9x5_clk_register_usb(struct at91_pmc *pmc, const char *name,
167 			    const char **parent_names, u8 num_parents)
168 {
169 	struct at91sam9x5_clk_usb *usb;
170 	struct clk *clk = NULL;
171 	struct clk_init_data init;
172 
173 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
174 	if (!usb)
175 		return ERR_PTR(-ENOMEM);
176 
177 	init.name = name;
178 	init.ops = &at91sam9x5_usb_ops;
179 	init.parent_names = parent_names;
180 	init.num_parents = num_parents;
181 	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
182 
183 	usb->hw.init = &init;
184 	usb->pmc = pmc;
185 
186 	clk = clk_register(NULL, &usb->hw);
187 	if (IS_ERR(clk))
188 		kfree(usb);
189 
190 	return clk;
191 }
192 
193 static struct clk * __init
194 at91sam9n12_clk_register_usb(struct at91_pmc *pmc, const char *name,
195 			     const char *parent_name)
196 {
197 	struct at91sam9x5_clk_usb *usb;
198 	struct clk *clk = NULL;
199 	struct clk_init_data init;
200 
201 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
202 	if (!usb)
203 		return ERR_PTR(-ENOMEM);
204 
205 	init.name = name;
206 	init.ops = &at91sam9n12_usb_ops;
207 	init.parent_names = &parent_name;
208 	init.num_parents = 1;
209 	init.flags = CLK_SET_RATE_GATE;
210 
211 	usb->hw.init = &init;
212 	usb->pmc = pmc;
213 
214 	clk = clk_register(NULL, &usb->hw);
215 	if (IS_ERR(clk))
216 		kfree(usb);
217 
218 	return clk;
219 }
220 
221 static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
222 						    unsigned long parent_rate)
223 {
224 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
225 	struct at91_pmc *pmc = usb->pmc;
226 	u32 tmp;
227 	u8 usbdiv;
228 
229 	tmp = pmc_read(pmc, AT91_CKGR_PLLBR);
230 	usbdiv = (tmp & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
231 	if (usb->divisors[usbdiv])
232 		return parent_rate / usb->divisors[usbdiv];
233 
234 	return 0;
235 }
236 
237 static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
238 					  unsigned long *parent_rate)
239 {
240 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
241 	unsigned long bestrate = 0;
242 	int bestdiff = -1;
243 	unsigned long tmprate;
244 	int tmpdiff;
245 	int i = 0;
246 
247 	for (i = 0; i < 4; i++) {
248 		if (!usb->divisors[i])
249 			continue;
250 		tmprate = *parent_rate / usb->divisors[i];
251 		if (tmprate < rate)
252 			tmpdiff = rate - tmprate;
253 		else
254 			tmpdiff = tmprate - rate;
255 
256 		if (bestdiff < 0 || bestdiff > tmpdiff) {
257 			bestrate = tmprate;
258 			bestdiff = tmpdiff;
259 		}
260 
261 		if (!bestdiff)
262 			break;
263 	}
264 
265 	return bestrate;
266 }
267 
268 static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
269 				       unsigned long parent_rate)
270 {
271 	u32 tmp;
272 	int i;
273 	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
274 	struct at91_pmc *pmc = usb->pmc;
275 	unsigned long div = parent_rate / rate;
276 
277 	if (parent_rate % rate)
278 		return -EINVAL;
279 	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
280 		if (usb->divisors[i] == div) {
281 			tmp = pmc_read(pmc, AT91_CKGR_PLLBR) &
282 			      ~AT91_PMC_USBDIV;
283 			tmp |= i << RM9200_USB_DIV_SHIFT;
284 			pmc_write(pmc, AT91_CKGR_PLLBR, tmp);
285 			return 0;
286 		}
287 	}
288 
289 	return -EINVAL;
290 }
291 
292 static const struct clk_ops at91rm9200_usb_ops = {
293 	.recalc_rate = at91rm9200_clk_usb_recalc_rate,
294 	.round_rate = at91rm9200_clk_usb_round_rate,
295 	.set_rate = at91rm9200_clk_usb_set_rate,
296 };
297 
298 static struct clk * __init
299 at91rm9200_clk_register_usb(struct at91_pmc *pmc, const char *name,
300 			    const char *parent_name, const u32 *divisors)
301 {
302 	struct at91rm9200_clk_usb *usb;
303 	struct clk *clk = NULL;
304 	struct clk_init_data init;
305 
306 	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
307 	if (!usb)
308 		return ERR_PTR(-ENOMEM);
309 
310 	init.name = name;
311 	init.ops = &at91rm9200_usb_ops;
312 	init.parent_names = &parent_name;
313 	init.num_parents = 1;
314 	init.flags = 0;
315 
316 	usb->hw.init = &init;
317 	usb->pmc = pmc;
318 	memcpy(usb->divisors, divisors, sizeof(usb->divisors));
319 
320 	clk = clk_register(NULL, &usb->hw);
321 	if (IS_ERR(clk))
322 		kfree(usb);
323 
324 	return clk;
325 }
326 
327 void __init of_at91sam9x5_clk_usb_setup(struct device_node *np,
328 					struct at91_pmc *pmc)
329 {
330 	struct clk *clk;
331 	int i;
332 	int num_parents;
333 	const char *parent_names[USB_SOURCE_MAX];
334 	const char *name = np->name;
335 
336 	num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
337 	if (num_parents <= 0 || num_parents > USB_SOURCE_MAX)
338 		return;
339 
340 	for (i = 0; i < num_parents; i++) {
341 		parent_names[i] = of_clk_get_parent_name(np, i);
342 		if (!parent_names[i])
343 			return;
344 	}
345 
346 	of_property_read_string(np, "clock-output-names", &name);
347 
348 	clk = at91sam9x5_clk_register_usb(pmc, name, parent_names, num_parents);
349 	if (IS_ERR(clk))
350 		return;
351 
352 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
353 }
354 
355 void __init of_at91sam9n12_clk_usb_setup(struct device_node *np,
356 					 struct at91_pmc *pmc)
357 {
358 	struct clk *clk;
359 	const char *parent_name;
360 	const char *name = np->name;
361 
362 	parent_name = of_clk_get_parent_name(np, 0);
363 	if (!parent_name)
364 		return;
365 
366 	of_property_read_string(np, "clock-output-names", &name);
367 
368 	clk = at91sam9n12_clk_register_usb(pmc, name, parent_name);
369 	if (IS_ERR(clk))
370 		return;
371 
372 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
373 }
374 
375 void __init of_at91rm9200_clk_usb_setup(struct device_node *np,
376 					struct at91_pmc *pmc)
377 {
378 	struct clk *clk;
379 	const char *parent_name;
380 	const char *name = np->name;
381 	u32 divisors[4] = {0, 0, 0, 0};
382 
383 	parent_name = of_clk_get_parent_name(np, 0);
384 	if (!parent_name)
385 		return;
386 
387 	of_property_read_u32_array(np, "atmel,clk-divisors", divisors, 4);
388 	if (!divisors[0])
389 		return;
390 
391 	of_property_read_string(np, "clock-output-names", &name);
392 
393 	clk = at91rm9200_clk_register_usb(pmc, name, parent_name, divisors);
394 	if (IS_ERR(clk))
395 		return;
396 
397 	of_clk_add_provider(np, of_clk_src_simple_get, clk);
398 }
399