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
28struct 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
36struct 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
45static 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
56	return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
57}
58
59static long at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
60					      unsigned long rate,
61					      unsigned long min_rate,
62					      unsigned long max_rate,
63					      unsigned long *best_parent_rate,
64					      struct clk_hw **best_parent_hw)
65{
66	struct clk *parent = NULL;
67	long best_rate = -EINVAL;
68	unsigned long tmp_rate;
69	int best_diff = -1;
70	int tmp_diff;
71	int i;
72
73	for (i = 0; i < __clk_get_num_parents(hw->clk); i++) {
74		int div;
75
76		parent = clk_get_parent_by_index(hw->clk, i);
77		if (!parent)
78			continue;
79
80		for (div = 1; div < SAM9X5_USB_MAX_DIV + 2; div++) {
81			unsigned long tmp_parent_rate;
82
83			tmp_parent_rate = rate * div;
84			tmp_parent_rate = __clk_round_rate(parent,
85							   tmp_parent_rate);
86			tmp_rate = DIV_ROUND_CLOSEST(tmp_parent_rate, div);
87			if (tmp_rate < rate)
88				tmp_diff = rate - tmp_rate;
89			else
90				tmp_diff = tmp_rate - rate;
91
92			if (best_diff < 0 || best_diff > tmp_diff) {
93				best_rate = tmp_rate;
94				best_diff = tmp_diff;
95				*best_parent_rate = tmp_parent_rate;
96				*best_parent_hw = __clk_get_hw(parent);
97			}
98
99			if (!best_diff || tmp_rate < rate)
100				break;
101		}
102
103		if (!best_diff)
104			break;
105	}
106
107	return best_rate;
108}
109
110static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index)
111{
112	u32 tmp;
113	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
114	struct at91_pmc *pmc = usb->pmc;
115
116	if (index > 1)
117		return -EINVAL;
118	tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS;
119	if (index)
120		tmp |= AT91_PMC_USBS;
121	pmc_write(pmc, AT91_PMC_USB, tmp);
122	return 0;
123}
124
125static u8 at91sam9x5_clk_usb_get_parent(struct clk_hw *hw)
126{
127	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
128	struct at91_pmc *pmc = usb->pmc;
129
130	return pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS;
131}
132
133static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
134				       unsigned long parent_rate)
135{
136	u32 tmp;
137	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
138	struct at91_pmc *pmc = usb->pmc;
139	unsigned long div;
140
141	if (!rate)
142		return -EINVAL;
143
144	div = DIV_ROUND_CLOSEST(parent_rate, rate);
145	if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
146		return -EINVAL;
147
148	tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV;
149	tmp |= (div - 1) << SAM9X5_USB_DIV_SHIFT;
150	pmc_write(pmc, AT91_PMC_USB, tmp);
151
152	return 0;
153}
154
155static const struct clk_ops at91sam9x5_usb_ops = {
156	.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
157	.determine_rate = at91sam9x5_clk_usb_determine_rate,
158	.get_parent = at91sam9x5_clk_usb_get_parent,
159	.set_parent = at91sam9x5_clk_usb_set_parent,
160	.set_rate = at91sam9x5_clk_usb_set_rate,
161};
162
163static int at91sam9n12_clk_usb_enable(struct clk_hw *hw)
164{
165	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
166	struct at91_pmc *pmc = usb->pmc;
167
168	pmc_write(pmc, AT91_PMC_USB,
169		  pmc_read(pmc, AT91_PMC_USB) | AT91_PMC_USBS);
170	return 0;
171}
172
173static void at91sam9n12_clk_usb_disable(struct clk_hw *hw)
174{
175	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
176	struct at91_pmc *pmc = usb->pmc;
177
178	pmc_write(pmc, AT91_PMC_USB,
179		  pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_USBS);
180}
181
182static int at91sam9n12_clk_usb_is_enabled(struct clk_hw *hw)
183{
184	struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
185	struct at91_pmc *pmc = usb->pmc;
186
187	return !!(pmc_read(pmc, AT91_PMC_USB) & AT91_PMC_USBS);
188}
189
190static const struct clk_ops at91sam9n12_usb_ops = {
191	.enable = at91sam9n12_clk_usb_enable,
192	.disable = at91sam9n12_clk_usb_disable,
193	.is_enabled = at91sam9n12_clk_usb_is_enabled,
194	.recalc_rate = at91sam9x5_clk_usb_recalc_rate,
195	.determine_rate = at91sam9x5_clk_usb_determine_rate,
196	.set_rate = at91sam9x5_clk_usb_set_rate,
197};
198
199static struct clk * __init
200at91sam9x5_clk_register_usb(struct at91_pmc *pmc, const char *name,
201			    const char **parent_names, u8 num_parents)
202{
203	struct at91sam9x5_clk_usb *usb;
204	struct clk *clk = NULL;
205	struct clk_init_data init;
206
207	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
208	if (!usb)
209		return ERR_PTR(-ENOMEM);
210
211	init.name = name;
212	init.ops = &at91sam9x5_usb_ops;
213	init.parent_names = parent_names;
214	init.num_parents = num_parents;
215	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |
216		     CLK_SET_RATE_PARENT;
217
218	usb->hw.init = &init;
219	usb->pmc = pmc;
220
221	clk = clk_register(NULL, &usb->hw);
222	if (IS_ERR(clk))
223		kfree(usb);
224
225	return clk;
226}
227
228static struct clk * __init
229at91sam9n12_clk_register_usb(struct at91_pmc *pmc, const char *name,
230			     const char *parent_name)
231{
232	struct at91sam9x5_clk_usb *usb;
233	struct clk *clk = NULL;
234	struct clk_init_data init;
235
236	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
237	if (!usb)
238		return ERR_PTR(-ENOMEM);
239
240	init.name = name;
241	init.ops = &at91sam9n12_usb_ops;
242	init.parent_names = &parent_name;
243	init.num_parents = 1;
244	init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
245
246	usb->hw.init = &init;
247	usb->pmc = pmc;
248
249	clk = clk_register(NULL, &usb->hw);
250	if (IS_ERR(clk))
251		kfree(usb);
252
253	return clk;
254}
255
256static unsigned long at91rm9200_clk_usb_recalc_rate(struct clk_hw *hw,
257						    unsigned long parent_rate)
258{
259	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
260	struct at91_pmc *pmc = usb->pmc;
261	u32 tmp;
262	u8 usbdiv;
263
264	tmp = pmc_read(pmc, AT91_CKGR_PLLBR);
265	usbdiv = (tmp & AT91_PMC_USBDIV) >> RM9200_USB_DIV_SHIFT;
266	if (usb->divisors[usbdiv])
267		return parent_rate / usb->divisors[usbdiv];
268
269	return 0;
270}
271
272static long at91rm9200_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate,
273					  unsigned long *parent_rate)
274{
275	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
276	struct clk *parent = __clk_get_parent(hw->clk);
277	unsigned long bestrate = 0;
278	int bestdiff = -1;
279	unsigned long tmprate;
280	int tmpdiff;
281	int i = 0;
282
283	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
284		unsigned long tmp_parent_rate;
285
286		if (!usb->divisors[i])
287			continue;
288
289		tmp_parent_rate = rate * usb->divisors[i];
290		tmp_parent_rate = __clk_round_rate(parent, tmp_parent_rate);
291		tmprate = DIV_ROUND_CLOSEST(tmp_parent_rate, usb->divisors[i]);
292		if (tmprate < rate)
293			tmpdiff = rate - tmprate;
294		else
295			tmpdiff = tmprate - rate;
296
297		if (bestdiff < 0 || bestdiff > tmpdiff) {
298			bestrate = tmprate;
299			bestdiff = tmpdiff;
300			*parent_rate = tmp_parent_rate;
301		}
302
303		if (!bestdiff)
304			break;
305	}
306
307	return bestrate;
308}
309
310static int at91rm9200_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
311				       unsigned long parent_rate)
312{
313	u32 tmp;
314	int i;
315	struct at91rm9200_clk_usb *usb = to_at91rm9200_clk_usb(hw);
316	struct at91_pmc *pmc = usb->pmc;
317	unsigned long div;
318
319	if (!rate)
320		return -EINVAL;
321
322	div = DIV_ROUND_CLOSEST(parent_rate, rate);
323
324	for (i = 0; i < RM9200_USB_DIV_TAB_SIZE; i++) {
325		if (usb->divisors[i] == div) {
326			tmp = pmc_read(pmc, AT91_CKGR_PLLBR) &
327			      ~AT91_PMC_USBDIV;
328			tmp |= i << RM9200_USB_DIV_SHIFT;
329			pmc_write(pmc, AT91_CKGR_PLLBR, tmp);
330			return 0;
331		}
332	}
333
334	return -EINVAL;
335}
336
337static const struct clk_ops at91rm9200_usb_ops = {
338	.recalc_rate = at91rm9200_clk_usb_recalc_rate,
339	.round_rate = at91rm9200_clk_usb_round_rate,
340	.set_rate = at91rm9200_clk_usb_set_rate,
341};
342
343static struct clk * __init
344at91rm9200_clk_register_usb(struct at91_pmc *pmc, const char *name,
345			    const char *parent_name, const u32 *divisors)
346{
347	struct at91rm9200_clk_usb *usb;
348	struct clk *clk = NULL;
349	struct clk_init_data init;
350
351	usb = kzalloc(sizeof(*usb), GFP_KERNEL);
352	if (!usb)
353		return ERR_PTR(-ENOMEM);
354
355	init.name = name;
356	init.ops = &at91rm9200_usb_ops;
357	init.parent_names = &parent_name;
358	init.num_parents = 1;
359	init.flags = CLK_SET_RATE_PARENT;
360
361	usb->hw.init = &init;
362	usb->pmc = pmc;
363	memcpy(usb->divisors, divisors, sizeof(usb->divisors));
364
365	clk = clk_register(NULL, &usb->hw);
366	if (IS_ERR(clk))
367		kfree(usb);
368
369	return clk;
370}
371
372void __init of_at91sam9x5_clk_usb_setup(struct device_node *np,
373					struct at91_pmc *pmc)
374{
375	struct clk *clk;
376	int i;
377	int num_parents;
378	const char *parent_names[USB_SOURCE_MAX];
379	const char *name = np->name;
380
381	num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
382	if (num_parents <= 0 || num_parents > USB_SOURCE_MAX)
383		return;
384
385	for (i = 0; i < num_parents; i++) {
386		parent_names[i] = of_clk_get_parent_name(np, i);
387		if (!parent_names[i])
388			return;
389	}
390
391	of_property_read_string(np, "clock-output-names", &name);
392
393	clk = at91sam9x5_clk_register_usb(pmc, name, parent_names, num_parents);
394	if (IS_ERR(clk))
395		return;
396
397	of_clk_add_provider(np, of_clk_src_simple_get, clk);
398}
399
400void __init of_at91sam9n12_clk_usb_setup(struct device_node *np,
401					 struct at91_pmc *pmc)
402{
403	struct clk *clk;
404	const char *parent_name;
405	const char *name = np->name;
406
407	parent_name = of_clk_get_parent_name(np, 0);
408	if (!parent_name)
409		return;
410
411	of_property_read_string(np, "clock-output-names", &name);
412
413	clk = at91sam9n12_clk_register_usb(pmc, name, parent_name);
414	if (IS_ERR(clk))
415		return;
416
417	of_clk_add_provider(np, of_clk_src_simple_get, clk);
418}
419
420void __init of_at91rm9200_clk_usb_setup(struct device_node *np,
421					struct at91_pmc *pmc)
422{
423	struct clk *clk;
424	const char *parent_name;
425	const char *name = np->name;
426	u32 divisors[4] = {0, 0, 0, 0};
427
428	parent_name = of_clk_get_parent_name(np, 0);
429	if (!parent_name)
430		return;
431
432	of_property_read_u32_array(np, "atmel,clk-divisors", divisors, 4);
433	if (!divisors[0])
434		return;
435
436	of_property_read_string(np, "clock-output-names", &name);
437
438	clk = at91rm9200_clk_register_usb(pmc, name, parent_name, divisors);
439	if (IS_ERR(clk))
440		return;
441
442	of_clk_add_provider(np, of_clk_src_simple_get, clk);
443}
444