1/*
2 * Copyright (c) 2014 MundoReader S.L.
3 * Author: Heiko Stuebner <heiko@sntech.de>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 */
15
16#include <asm/div64.h>
17#include <linux/slab.h>
18#include <linux/io.h>
19#include <linux/delay.h>
20#include <linux/clk.h>
21#include <linux/clk-provider.h>
22#include <linux/regmap.h>
23#include "clk.h"
24
25#define PLL_MODE_MASK		0x3
26#define PLL_MODE_SLOW		0x0
27#define PLL_MODE_NORM		0x1
28#define PLL_MODE_DEEP		0x2
29
30struct rockchip_clk_pll {
31	struct clk_hw		hw;
32
33	struct clk_mux		pll_mux;
34	const struct clk_ops	*pll_mux_ops;
35
36	struct notifier_block	clk_nb;
37
38	void __iomem		*reg_base;
39	int			lock_offset;
40	unsigned int		lock_shift;
41	enum rockchip_pll_type	type;
42	u8			flags;
43	const struct rockchip_pll_rate_table *rate_table;
44	unsigned int		rate_count;
45	spinlock_t		*lock;
46};
47
48#define to_rockchip_clk_pll(_hw) container_of(_hw, struct rockchip_clk_pll, hw)
49#define to_rockchip_clk_pll_nb(nb) \
50			container_of(nb, struct rockchip_clk_pll, clk_nb)
51
52static const struct rockchip_pll_rate_table *rockchip_get_pll_settings(
53			    struct rockchip_clk_pll *pll, unsigned long rate)
54{
55	const struct rockchip_pll_rate_table  *rate_table = pll->rate_table;
56	int i;
57
58	for (i = 0; i < pll->rate_count; i++) {
59		if (rate == rate_table[i].rate)
60			return &rate_table[i];
61	}
62
63	return NULL;
64}
65
66static long rockchip_pll_round_rate(struct clk_hw *hw,
67			    unsigned long drate, unsigned long *prate)
68{
69	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
70	const struct rockchip_pll_rate_table *rate_table = pll->rate_table;
71	int i;
72
73	/* Assumming rate_table is in descending order */
74	for (i = 0; i < pll->rate_count; i++) {
75		if (drate >= rate_table[i].rate)
76			return rate_table[i].rate;
77	}
78
79	/* return minimum supported value */
80	return rate_table[i - 1].rate;
81}
82
83/*
84 * Wait for the pll to reach the locked state.
85 * The calling set_rate function is responsible for making sure the
86 * grf regmap is available.
87 */
88static int rockchip_pll_wait_lock(struct rockchip_clk_pll *pll)
89{
90	struct regmap *grf = rockchip_clk_get_grf();
91	unsigned int val;
92	int delay = 24000000, ret;
93
94	while (delay > 0) {
95		ret = regmap_read(grf, pll->lock_offset, &val);
96		if (ret) {
97			pr_err("%s: failed to read pll lock status: %d\n",
98			       __func__, ret);
99			return ret;
100		}
101
102		if (val & BIT(pll->lock_shift))
103			return 0;
104		delay--;
105	}
106
107	pr_err("%s: timeout waiting for pll to lock\n", __func__);
108	return -ETIMEDOUT;
109}
110
111/**
112 * PLL used in RK3066, RK3188 and RK3288
113 */
114
115#define RK3066_PLL_RESET_DELAY(nr)	((nr * 500) / 24 + 1)
116
117#define RK3066_PLLCON(i)		(i * 0x4)
118#define RK3066_PLLCON0_OD_MASK		0xf
119#define RK3066_PLLCON0_OD_SHIFT		0
120#define RK3066_PLLCON0_NR_MASK		0x3f
121#define RK3066_PLLCON0_NR_SHIFT		8
122#define RK3066_PLLCON1_NF_MASK		0x1fff
123#define RK3066_PLLCON1_NF_SHIFT		0
124#define RK3066_PLLCON2_BWADJ_MASK	0xfff
125#define RK3066_PLLCON2_BWADJ_SHIFT	0
126#define RK3066_PLLCON3_RESET		(1 << 5)
127#define RK3066_PLLCON3_PWRDOWN		(1 << 1)
128#define RK3066_PLLCON3_BYPASS		(1 << 0)
129
130static unsigned long rockchip_rk3066_pll_recalc_rate(struct clk_hw *hw,
131						     unsigned long prate)
132{
133	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
134	u64 nf, nr, no, rate64 = prate;
135	u32 pllcon;
136
137	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(3));
138	if (pllcon & RK3066_PLLCON3_BYPASS) {
139		pr_debug("%s: pll %s is bypassed\n", __func__,
140			__clk_get_name(hw->clk));
141		return prate;
142	}
143
144	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(1));
145	nf = (pllcon >> RK3066_PLLCON1_NF_SHIFT) & RK3066_PLLCON1_NF_MASK;
146
147	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(0));
148	nr = (pllcon >> RK3066_PLLCON0_NR_SHIFT) & RK3066_PLLCON0_NR_MASK;
149	no = (pllcon >> RK3066_PLLCON0_OD_SHIFT) & RK3066_PLLCON0_OD_MASK;
150
151	rate64 *= (nf + 1);
152	do_div(rate64, nr + 1);
153	do_div(rate64, no + 1);
154
155	return (unsigned long)rate64;
156}
157
158static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate,
159					unsigned long prate)
160{
161	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
162	const struct rockchip_pll_rate_table *rate;
163	unsigned long old_rate = rockchip_rk3066_pll_recalc_rate(hw, prate);
164	struct regmap *grf = rockchip_clk_get_grf();
165	struct clk_mux *pll_mux = &pll->pll_mux;
166	const struct clk_ops *pll_mux_ops = pll->pll_mux_ops;
167	int rate_change_remuxed = 0;
168	int cur_parent;
169	int ret;
170
171	if (IS_ERR(grf)) {
172		pr_debug("%s: grf regmap not available, aborting rate change\n",
173			 __func__);
174		return PTR_ERR(grf);
175	}
176
177	pr_debug("%s: changing %s from %lu to %lu with a parent rate of %lu\n",
178		 __func__, __clk_get_name(hw->clk), old_rate, drate, prate);
179
180	/* Get required rate settings from table */
181	rate = rockchip_get_pll_settings(pll, drate);
182	if (!rate) {
183		pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__,
184			drate, __clk_get_name(hw->clk));
185		return -EINVAL;
186	}
187
188	pr_debug("%s: rate settings for %lu (nr, no, nf): (%d, %d, %d)\n",
189		 __func__, rate->rate, rate->nr, rate->no, rate->nf);
190
191	cur_parent = pll_mux_ops->get_parent(&pll_mux->hw);
192	if (cur_parent == PLL_MODE_NORM) {
193		pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_SLOW);
194		rate_change_remuxed = 1;
195	}
196
197	/* enter reset mode */
198	writel(HIWORD_UPDATE(RK3066_PLLCON3_RESET, RK3066_PLLCON3_RESET, 0),
199	       pll->reg_base + RK3066_PLLCON(3));
200
201	/* update pll values */
202	writel(HIWORD_UPDATE(rate->nr - 1, RK3066_PLLCON0_NR_MASK,
203					   RK3066_PLLCON0_NR_SHIFT) |
204	       HIWORD_UPDATE(rate->no - 1, RK3066_PLLCON0_OD_MASK,
205					   RK3066_PLLCON0_OD_SHIFT),
206	       pll->reg_base + RK3066_PLLCON(0));
207
208	writel_relaxed(HIWORD_UPDATE(rate->nf - 1, RK3066_PLLCON1_NF_MASK,
209						   RK3066_PLLCON1_NF_SHIFT),
210		       pll->reg_base + RK3066_PLLCON(1));
211	writel_relaxed(HIWORD_UPDATE(rate->bwadj, RK3066_PLLCON2_BWADJ_MASK,
212						  RK3066_PLLCON2_BWADJ_SHIFT),
213		       pll->reg_base + RK3066_PLLCON(2));
214
215	/* leave reset and wait the reset_delay */
216	writel(HIWORD_UPDATE(0, RK3066_PLLCON3_RESET, 0),
217	       pll->reg_base + RK3066_PLLCON(3));
218	udelay(RK3066_PLL_RESET_DELAY(rate->nr));
219
220	/* wait for the pll to lock */
221	ret = rockchip_pll_wait_lock(pll);
222	if (ret) {
223		pr_warn("%s: pll did not lock, trying to restore old rate %lu\n",
224			__func__, old_rate);
225		rockchip_rk3066_pll_set_rate(hw, old_rate, prate);
226	}
227
228	if (rate_change_remuxed)
229		pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_NORM);
230
231	return ret;
232}
233
234static int rockchip_rk3066_pll_enable(struct clk_hw *hw)
235{
236	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
237
238	writel(HIWORD_UPDATE(0, RK3066_PLLCON3_PWRDOWN, 0),
239	       pll->reg_base + RK3066_PLLCON(3));
240
241	return 0;
242}
243
244static void rockchip_rk3066_pll_disable(struct clk_hw *hw)
245{
246	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
247
248	writel(HIWORD_UPDATE(RK3066_PLLCON3_PWRDOWN,
249			     RK3066_PLLCON3_PWRDOWN, 0),
250	       pll->reg_base + RK3066_PLLCON(3));
251}
252
253static int rockchip_rk3066_pll_is_enabled(struct clk_hw *hw)
254{
255	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
256	u32 pllcon = readl(pll->reg_base + RK3066_PLLCON(3));
257
258	return !(pllcon & RK3066_PLLCON3_PWRDOWN);
259}
260
261static void rockchip_rk3066_pll_init(struct clk_hw *hw)
262{
263	struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
264	const struct rockchip_pll_rate_table *rate;
265	unsigned int nf, nr, no, bwadj;
266	unsigned long drate;
267	u32 pllcon;
268
269	if (!(pll->flags & ROCKCHIP_PLL_SYNC_RATE))
270		return;
271
272	drate = __clk_get_rate(hw->clk);
273	rate = rockchip_get_pll_settings(pll, drate);
274
275	/* when no rate setting for the current rate, rely on clk_set_rate */
276	if (!rate)
277		return;
278
279	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(0));
280	nr = ((pllcon >> RK3066_PLLCON0_NR_SHIFT) & RK3066_PLLCON0_NR_MASK) + 1;
281	no = ((pllcon >> RK3066_PLLCON0_OD_SHIFT) & RK3066_PLLCON0_OD_MASK) + 1;
282
283	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(1));
284	nf = ((pllcon >> RK3066_PLLCON1_NF_SHIFT) & RK3066_PLLCON1_NF_MASK) + 1;
285
286	pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(2));
287	bwadj = (pllcon >> RK3066_PLLCON2_BWADJ_SHIFT) & RK3066_PLLCON2_BWADJ_MASK;
288
289	pr_debug("%s: pll %s@%lu: nr (%d:%d); no (%d:%d); nf(%d:%d), bwadj(%d:%d)\n",
290		 __func__, __clk_get_name(hw->clk), drate, rate->nr, nr,
291		rate->no, no, rate->nf, nf, rate->bwadj, bwadj);
292	if (rate->nr != nr || rate->no != no || rate->nf != nf
293					     || rate->bwadj != bwadj) {
294		struct clk *parent = __clk_get_parent(hw->clk);
295		unsigned long prate;
296
297		if (!parent) {
298			pr_warn("%s: parent of %s not available\n",
299				__func__, __clk_get_name(hw->clk));
300			return;
301		}
302
303		pr_debug("%s: pll %s: rate params do not match rate table, adjusting\n",
304			 __func__, __clk_get_name(hw->clk));
305		prate = __clk_get_rate(parent);
306		rockchip_rk3066_pll_set_rate(hw, drate, prate);
307	}
308}
309
310static const struct clk_ops rockchip_rk3066_pll_clk_norate_ops = {
311	.recalc_rate = rockchip_rk3066_pll_recalc_rate,
312	.enable = rockchip_rk3066_pll_enable,
313	.disable = rockchip_rk3066_pll_disable,
314	.is_enabled = rockchip_rk3066_pll_is_enabled,
315};
316
317static const struct clk_ops rockchip_rk3066_pll_clk_ops = {
318	.recalc_rate = rockchip_rk3066_pll_recalc_rate,
319	.round_rate = rockchip_pll_round_rate,
320	.set_rate = rockchip_rk3066_pll_set_rate,
321	.enable = rockchip_rk3066_pll_enable,
322	.disable = rockchip_rk3066_pll_disable,
323	.is_enabled = rockchip_rk3066_pll_is_enabled,
324	.init = rockchip_rk3066_pll_init,
325};
326
327/*
328 * Common registering of pll clocks
329 */
330
331struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type,
332		const char *name, const char **parent_names, u8 num_parents,
333		void __iomem *base, int con_offset, int grf_lock_offset,
334		int lock_shift, int mode_offset, int mode_shift,
335		struct rockchip_pll_rate_table *rate_table,
336		u8 clk_pll_flags, spinlock_t *lock)
337{
338	const char *pll_parents[3];
339	struct clk_init_data init;
340	struct rockchip_clk_pll *pll;
341	struct clk_mux *pll_mux;
342	struct clk *pll_clk, *mux_clk;
343	char pll_name[20];
344
345	if (num_parents != 2) {
346		pr_err("%s: needs two parent clocks\n", __func__);
347		return ERR_PTR(-EINVAL);
348	}
349
350	/* name the actual pll */
351	snprintf(pll_name, sizeof(pll_name), "pll_%s", name);
352
353	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
354	if (!pll)
355		return ERR_PTR(-ENOMEM);
356
357	init.name = pll_name;
358
359	/* keep all plls untouched for now */
360	init.flags = CLK_IGNORE_UNUSED;
361
362	init.parent_names = &parent_names[0];
363	init.num_parents = 1;
364
365	if (rate_table) {
366		int len;
367
368		/* find count of rates in rate_table */
369		for (len = 0; rate_table[len].rate != 0; )
370			len++;
371
372		pll->rate_count = len;
373		pll->rate_table = kmemdup(rate_table,
374					pll->rate_count *
375					sizeof(struct rockchip_pll_rate_table),
376					GFP_KERNEL);
377		WARN(!pll->rate_table,
378			"%s: could not allocate rate table for %s\n",
379			__func__, name);
380	}
381
382	switch (pll_type) {
383	case pll_rk3066:
384		if (!pll->rate_table)
385			init.ops = &rockchip_rk3066_pll_clk_norate_ops;
386		else
387			init.ops = &rockchip_rk3066_pll_clk_ops;
388		break;
389	default:
390		pr_warn("%s: Unknown pll type for pll clk %s\n",
391			__func__, name);
392	}
393
394	pll->hw.init = &init;
395	pll->type = pll_type;
396	pll->reg_base = base + con_offset;
397	pll->lock_offset = grf_lock_offset;
398	pll->lock_shift = lock_shift;
399	pll->flags = clk_pll_flags;
400	pll->lock = lock;
401
402	/* create the mux on top of the real pll */
403	pll->pll_mux_ops = &clk_mux_ops;
404	pll_mux = &pll->pll_mux;
405	pll_mux->reg = base + mode_offset;
406	pll_mux->shift = mode_shift;
407	pll_mux->mask = PLL_MODE_MASK;
408	pll_mux->flags = 0;
409	pll_mux->lock = lock;
410	pll_mux->hw.init = &init;
411
412	if (pll_type == pll_rk3066)
413		pll_mux->flags |= CLK_MUX_HIWORD_MASK;
414
415	pll_clk = clk_register(NULL, &pll->hw);
416	if (IS_ERR(pll_clk)) {
417		pr_err("%s: failed to register pll clock %s : %ld\n",
418			__func__, name, PTR_ERR(pll_clk));
419		mux_clk = pll_clk;
420		goto err_pll;
421	}
422
423	/* the actual muxing is xin24m, pll-output, xin32k */
424	pll_parents[0] = parent_names[0];
425	pll_parents[1] = pll_name;
426	pll_parents[2] = parent_names[1];
427
428	init.name = name;
429	init.flags = CLK_SET_RATE_PARENT;
430	init.ops = pll->pll_mux_ops;
431	init.parent_names = pll_parents;
432	init.num_parents = ARRAY_SIZE(pll_parents);
433
434	mux_clk = clk_register(NULL, &pll_mux->hw);
435	if (IS_ERR(mux_clk))
436		goto err_mux;
437
438	return mux_clk;
439
440err_mux:
441	clk_unregister(pll_clk);
442err_pll:
443	kfree(pll);
444	return mux_clk;
445}
446