1/*
2 * Copyright (C) 2014 Texas Instruments Incorporated
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 as published by
6 * the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program.  If not, see <http://www.gnu.org/licenses/>.
15 */
16
17#define DSS_SUBSYS_NAME "PLL"
18
19#include <linux/clk.h>
20#include <linux/io.h>
21#include <linux/kernel.h>
22#include <linux/regulator/consumer.h>
23#include <linux/sched.h>
24
25#include <video/omapdss.h>
26
27#include "dss.h"
28
29#define PLL_CONTROL			0x0000
30#define PLL_STATUS			0x0004
31#define PLL_GO				0x0008
32#define PLL_CONFIGURATION1		0x000C
33#define PLL_CONFIGURATION2		0x0010
34#define PLL_CONFIGURATION3		0x0014
35#define PLL_SSC_CONFIGURATION1		0x0018
36#define PLL_SSC_CONFIGURATION2		0x001C
37#define PLL_CONFIGURATION4		0x0020
38
39static struct dss_pll *dss_plls[4];
40
41int dss_pll_register(struct dss_pll *pll)
42{
43	int i;
44
45	for (i = 0; i < ARRAY_SIZE(dss_plls); ++i) {
46		if (!dss_plls[i]) {
47			dss_plls[i] = pll;
48			return 0;
49		}
50	}
51
52	return -EBUSY;
53}
54
55void dss_pll_unregister(struct dss_pll *pll)
56{
57	int i;
58
59	for (i = 0; i < ARRAY_SIZE(dss_plls); ++i) {
60		if (dss_plls[i] == pll) {
61			dss_plls[i] = NULL;
62			return;
63		}
64	}
65}
66
67struct dss_pll *dss_pll_find(const char *name)
68{
69	int i;
70
71	for (i = 0; i < ARRAY_SIZE(dss_plls); ++i) {
72		if (dss_plls[i] && strcmp(dss_plls[i]->name, name) == 0)
73			return dss_plls[i];
74	}
75
76	return NULL;
77}
78
79int dss_pll_enable(struct dss_pll *pll)
80{
81	int r;
82
83	r = clk_prepare_enable(pll->clkin);
84	if (r)
85		return r;
86
87	if (pll->regulator) {
88		r = regulator_enable(pll->regulator);
89		if (r)
90			goto err_reg;
91	}
92
93	r = pll->ops->enable(pll);
94	if (r)
95		goto err_enable;
96
97	return 0;
98
99err_enable:
100	if (pll->regulator)
101		regulator_disable(pll->regulator);
102err_reg:
103	clk_disable_unprepare(pll->clkin);
104	return r;
105}
106
107void dss_pll_disable(struct dss_pll *pll)
108{
109	pll->ops->disable(pll);
110
111	if (pll->regulator)
112		regulator_disable(pll->regulator);
113
114	clk_disable_unprepare(pll->clkin);
115
116	memset(&pll->cinfo, 0, sizeof(pll->cinfo));
117}
118
119int dss_pll_set_config(struct dss_pll *pll, const struct dss_pll_clock_info *cinfo)
120{
121	int r;
122
123	r = pll->ops->set_config(pll, cinfo);
124	if (r)
125		return r;
126
127	pll->cinfo = *cinfo;
128
129	return 0;
130}
131
132bool dss_pll_hsdiv_calc(const struct dss_pll *pll, unsigned long clkdco,
133		unsigned long out_min, unsigned long out_max,
134		dss_hsdiv_calc_func func, void *data)
135{
136	const struct dss_pll_hw *hw = pll->hw;
137	int m, m_start, m_stop;
138	unsigned long out;
139
140	out_min = out_min ? out_min : 1;
141	out_max = out_max ? out_max : ULONG_MAX;
142
143	m_start = max(DIV_ROUND_UP(clkdco, out_max), 1ul);
144
145	m_stop = min((unsigned)(clkdco / out_min), hw->mX_max);
146
147	for (m = m_start; m <= m_stop; ++m) {
148		out = clkdco / m;
149
150		if (func(m, out, data))
151			return true;
152	}
153
154	return false;
155}
156
157bool dss_pll_calc(const struct dss_pll *pll, unsigned long clkin,
158		unsigned long pll_min, unsigned long pll_max,
159		dss_pll_calc_func func, void *data)
160{
161	const struct dss_pll_hw *hw = pll->hw;
162	int n, n_start, n_stop;
163	int m, m_start, m_stop;
164	unsigned long fint, clkdco;
165	unsigned long pll_hw_max;
166	unsigned long fint_hw_min, fint_hw_max;
167
168	pll_hw_max = hw->clkdco_max;
169
170	fint_hw_min = hw->fint_min;
171	fint_hw_max = hw->fint_max;
172
173	n_start = max(DIV_ROUND_UP(clkin, fint_hw_max), 1ul);
174	n_stop = min((unsigned)(clkin / fint_hw_min), hw->n_max);
175
176	pll_max = pll_max ? pll_max : ULONG_MAX;
177
178	for (n = n_start; n <= n_stop; ++n) {
179		fint = clkin / n;
180
181		m_start = max(DIV_ROUND_UP(DIV_ROUND_UP(pll_min, fint), 2),
182				1ul);
183		m_stop = min3((unsigned)(pll_max / fint / 2),
184				(unsigned)(pll_hw_max / fint / 2),
185				hw->m_max);
186
187		for (m = m_start; m <= m_stop; ++m) {
188			clkdco = 2 * m * fint;
189
190			if (func(n, m, fint, clkdco, data))
191				return true;
192		}
193	}
194
195	return false;
196}
197
198static int wait_for_bit_change(void __iomem *reg, int bitnum, int value)
199{
200	unsigned long timeout;
201	ktime_t wait;
202	int t;
203
204	/* first busyloop to see if the bit changes right away */
205	t = 100;
206	while (t-- > 0) {
207		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
208			return value;
209	}
210
211	/* then loop for 500ms, sleeping for 1ms in between */
212	timeout = jiffies + msecs_to_jiffies(500);
213	while (time_before(jiffies, timeout)) {
214		if (FLD_GET(readl_relaxed(reg), bitnum, bitnum) == value)
215			return value;
216
217		wait = ns_to_ktime(1000 * 1000);
218		set_current_state(TASK_UNINTERRUPTIBLE);
219		schedule_hrtimeout(&wait, HRTIMER_MODE_REL);
220	}
221
222	return !value;
223}
224
225int dss_pll_wait_reset_done(struct dss_pll *pll)
226{
227	void __iomem *base = pll->base;
228
229	if (wait_for_bit_change(base + PLL_STATUS, 0, 1) != 1)
230		return -ETIMEDOUT;
231	else
232		return 0;
233}
234
235static int dss_wait_hsdiv_ack(struct dss_pll *pll, u32 hsdiv_ack_mask)
236{
237	int t = 100;
238
239	while (t-- > 0) {
240		u32 v = readl_relaxed(pll->base + PLL_STATUS);
241		v &= hsdiv_ack_mask;
242		if (v == hsdiv_ack_mask)
243			return 0;
244	}
245
246	return -ETIMEDOUT;
247}
248
249int dss_pll_write_config_type_a(struct dss_pll *pll,
250		const struct dss_pll_clock_info *cinfo)
251{
252	const struct dss_pll_hw *hw = pll->hw;
253	void __iomem *base = pll->base;
254	int r = 0;
255	u32 l;
256
257	l = 0;
258	if (hw->has_stopmode)
259		l = FLD_MOD(l, 1, 0, 0);		/* PLL_STOPMODE */
260	l = FLD_MOD(l, cinfo->n - 1, hw->n_msb, hw->n_lsb);	/* PLL_REGN */
261	l = FLD_MOD(l, cinfo->m, hw->m_msb, hw->m_lsb);		/* PLL_REGM */
262	/* M4 */
263	l = FLD_MOD(l, cinfo->mX[0] ? cinfo->mX[0] - 1 : 0,
264			hw->mX_msb[0], hw->mX_lsb[0]);
265	/* M5 */
266	l = FLD_MOD(l, cinfo->mX[1] ? cinfo->mX[1] - 1 : 0,
267			hw->mX_msb[1], hw->mX_lsb[1]);
268	writel_relaxed(l, base + PLL_CONFIGURATION1);
269
270	l = 0;
271	/* M6 */
272	l = FLD_MOD(l, cinfo->mX[2] ? cinfo->mX[2] - 1 : 0,
273			hw->mX_msb[2], hw->mX_lsb[2]);
274	/* M7 */
275	l = FLD_MOD(l, cinfo->mX[3] ? cinfo->mX[3] - 1 : 0,
276			hw->mX_msb[3], hw->mX_lsb[3]);
277	writel_relaxed(l, base + PLL_CONFIGURATION3);
278
279	l = readl_relaxed(base + PLL_CONFIGURATION2);
280	if (hw->has_freqsel) {
281		u32 f = cinfo->fint < 1000000 ? 0x3 :
282			cinfo->fint < 1250000 ? 0x4 :
283			cinfo->fint < 1500000 ? 0x5 :
284			cinfo->fint < 1750000 ? 0x6 :
285			0x7;
286
287		l = FLD_MOD(l, f, 4, 1);	/* PLL_FREQSEL */
288	} else if (hw->has_selfreqdco) {
289		u32 f = cinfo->clkdco < hw->clkdco_low ? 0x2 : 0x4;
290
291		l = FLD_MOD(l, f, 3, 1);	/* PLL_SELFREQDCO */
292	}
293	l = FLD_MOD(l, 1, 13, 13);		/* PLL_REFEN */
294	l = FLD_MOD(l, 0, 14, 14);		/* PHY_CLKINEN */
295	l = FLD_MOD(l, 0, 16, 16);		/* M4_CLOCK_EN */
296	l = FLD_MOD(l, 0, 18, 18);		/* M5_CLOCK_EN */
297	l = FLD_MOD(l, 1, 20, 20);		/* HSDIVBYPASS */
298	if (hw->has_refsel)
299		l = FLD_MOD(l, 3, 22, 21);	/* REFSEL = sysclk */
300	l = FLD_MOD(l, 0, 23, 23);		/* M6_CLOCK_EN */
301	l = FLD_MOD(l, 0, 25, 25);		/* M7_CLOCK_EN */
302	writel_relaxed(l, base + PLL_CONFIGURATION2);
303
304	writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
305
306	if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
307		DSSERR("DSS DPLL GO bit not going down.\n");
308		r = -EIO;
309		goto err;
310	}
311
312	if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
313		DSSERR("cannot lock DSS DPLL\n");
314		r = -EIO;
315		goto err;
316	}
317
318	l = readl_relaxed(base + PLL_CONFIGURATION2);
319	l = FLD_MOD(l, 1, 14, 14);			/* PHY_CLKINEN */
320	l = FLD_MOD(l, cinfo->mX[0] ? 1 : 0, 16, 16);	/* M4_CLOCK_EN */
321	l = FLD_MOD(l, cinfo->mX[1] ? 1 : 0, 18, 18);	/* M5_CLOCK_EN */
322	l = FLD_MOD(l, 0, 20, 20);			/* HSDIVBYPASS */
323	l = FLD_MOD(l, cinfo->mX[2] ? 1 : 0, 23, 23);	/* M6_CLOCK_EN */
324	l = FLD_MOD(l, cinfo->mX[3] ? 1 : 0, 25, 25);	/* M7_CLOCK_EN */
325	writel_relaxed(l, base + PLL_CONFIGURATION2);
326
327	r = dss_wait_hsdiv_ack(pll,
328		(cinfo->mX[0] ? BIT(7) : 0) |
329		(cinfo->mX[1] ? BIT(8) : 0) |
330		(cinfo->mX[2] ? BIT(10) : 0) |
331		(cinfo->mX[3] ? BIT(11) : 0));
332	if (r) {
333		DSSERR("failed to enable HSDIV clocks\n");
334		goto err;
335	}
336
337err:
338	return r;
339}
340
341int dss_pll_write_config_type_b(struct dss_pll *pll,
342		const struct dss_pll_clock_info *cinfo)
343{
344	const struct dss_pll_hw *hw = pll->hw;
345	void __iomem *base = pll->base;
346	u32 l;
347
348	l = 0;
349	l = FLD_MOD(l, cinfo->m, 20, 9);	/* PLL_REGM */
350	l = FLD_MOD(l, cinfo->n - 1, 8, 1);	/* PLL_REGN */
351	writel_relaxed(l, base + PLL_CONFIGURATION1);
352
353	l = readl_relaxed(base + PLL_CONFIGURATION2);
354	l = FLD_MOD(l, 0x0, 12, 12);	/* PLL_HIGHFREQ divide by 2 */
355	l = FLD_MOD(l, 0x1, 13, 13);	/* PLL_REFEN */
356	l = FLD_MOD(l, 0x0, 14, 14);	/* PHY_CLKINEN */
357	if (hw->has_refsel)
358		l = FLD_MOD(l, 0x3, 22, 21);	/* REFSEL = SYSCLK */
359
360	/* PLL_SELFREQDCO */
361	if (cinfo->clkdco > hw->clkdco_low)
362		l = FLD_MOD(l, 0x4, 3, 1);
363	else
364		l = FLD_MOD(l, 0x2, 3, 1);
365	writel_relaxed(l, base + PLL_CONFIGURATION2);
366
367	l = readl_relaxed(base + PLL_CONFIGURATION3);
368	l = FLD_MOD(l, cinfo->sd, 17, 10);	/* PLL_REGSD */
369	writel_relaxed(l, base + PLL_CONFIGURATION3);
370
371	l = readl_relaxed(base + PLL_CONFIGURATION4);
372	l = FLD_MOD(l, cinfo->mX[0], 24, 18);	/* PLL_REGM2 */
373	l = FLD_MOD(l, cinfo->mf, 17, 0);	/* PLL_REGM_F */
374	writel_relaxed(l, base + PLL_CONFIGURATION4);
375
376	writel_relaxed(1, base + PLL_GO);	/* PLL_GO */
377
378	if (wait_for_bit_change(base + PLL_GO, 0, 0) != 0) {
379		DSSERR("DSS DPLL GO bit not going down.\n");
380		return -EIO;
381	}
382
383	if (wait_for_bit_change(base + PLL_STATUS, 1, 1) != 1) {
384		DSSERR("cannot lock DSS DPLL\n");
385		return -ETIMEDOUT;
386	}
387
388	return 0;
389}
390