summaryrefslogtreecommitdiffstats
path: root/drivers/clk/qcom/clk-pll.c
blob: 0f927c538613e63b7461b5b972caac927de98255 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/bug.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/clk-provider.h>
#include <linux/regmap.h>

#include <asm/div64.h>

#include "clk-pll.h"

#define PLL_OUTCTRL		BIT(0)
#define PLL_BYPASSNL		BIT(1)
#define PLL_RESET_N		BIT(2)
#define PLL_LOCK_COUNT_SHIFT	8
#define PLL_LOCK_COUNT_MASK	0x3f
#define PLL_BIAS_COUNT_SHIFT	14
#define PLL_BIAS_COUNT_MASK	0x3f
#define PLL_VOTE_FSM_ENA	BIT(20)
#define PLL_VOTE_FSM_RESET	BIT(21)

static int clk_pll_enable(struct clk_hw *hw)
{
	struct clk_pll *pll = to_clk_pll(hw);
	int ret;
	u32 mask, val;

	mask = PLL_OUTCTRL | PLL_RESET_N | PLL_BYPASSNL;
	ret = regmap_read(pll->clkr.regmap, pll->mode_reg, &val);
	if (ret)
		return ret;

	/* Skip if already enabled or in FSM mode */
	if ((val & mask) == mask || val & PLL_VOTE_FSM_ENA)
		return 0;

	/* Disable PLL bypass mode. */
	ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_BYPASSNL,
				 PLL_BYPASSNL);
	if (ret)
		return ret;

	/*
	 * H/W requires a 5us delay between disabling the bypass and
	 * de-asserting the reset. Delay 10us just to be safe.
	 */
	udelay(10);

	/* De-assert active-low PLL reset. */
	ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_RESET_N,
				 PLL_RESET_N);
	if (ret)
		return ret;

	/* Wait until PLL is locked. */
	udelay(50);

	/* Enable PLL output. */
	ret = regmap_update_bits(pll->clkr.regmap, pll->mode_reg, PLL_OUTCTRL,
				 PLL_OUTCTRL);
	if (ret)
		return ret;

	return 0;
}

static void clk_pll_disable(struct clk_hw *hw)
{
	struct clk_pll *pll = to_clk_pll(hw);
	u32 mask;
	u32 val;

	regmap_read(pll->clkr.regmap, pll->mode_reg, &val);
	/* Skip if in FSM mode */
	if (val & PLL_VOTE_FSM_ENA)
		return;
	mask = PLL_OUTCTRL | PLL_RESET_N | PLL_BYPASSNL;
	regmap_update_bits(pll->clkr.regmap, pll->mode_reg, mask, 0);
}

static unsigned long
clk_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
{
	struct clk_pll *pll = to_clk_pll(hw);
	u32 l, m, n;
	unsigned long rate;
	u64 tmp;

	regmap_read(pll->clkr.regmap, pll->l_reg, &l);
	regmap_read(pll->clkr.regmap, pll->m_reg, &m);
	regmap_read(pll->clkr.regmap, pll->n_reg, &n);

	l &= 0x3ff;
	m &= 0x7ffff;
	n &= 0x7ffff;

	rate = parent_rate * l;
	if (n) {
		tmp = parent_rate;
		tmp *= m;
		do_div(tmp, n);
		rate += tmp;
	}
	return rate;
}

const struct clk_ops clk_pll_ops = {
	.enable = clk_pll_enable,
	.disable = clk_pll_disable,
	.recalc_rate = clk_pll_recalc_rate,
};
EXPORT_SYMBOL_GPL(clk_pll_ops);

static int wait_for_pll(struct clk_pll *pll)
{
	u32 val;
	int count;
	int ret;
	const char *name = __clk_get_name(pll->clkr.hw.clk);

	/* Wait for pll to enable. */
	for (count = 200; count > 0; count--) {
		ret = regmap_read(pll->clkr.regmap, pll->status_reg, &val);
		if (ret)
			return ret;
		if (val & BIT(pll->status_bit))
			return 0;
		udelay(1);
	}

	WARN(1, "%s didn't enable after voting for it!\n", name);
	return -ETIMEDOUT;
}

static int clk_pll_vote_enable(struct clk_hw *hw)
{
	int ret;
	struct clk_pll *p = to_clk_pll(__clk_get_hw(__clk_get_parent(hw->clk)));

	ret = clk_enable_regmap(hw);
	if (ret)
		return ret;

	return wait_for_pll(p);
}

const struct clk_ops clk_pll_vote_ops = {
	.enable = clk_pll_vote_enable,
	.disable = clk_disable_regmap,
};
EXPORT_SYMBOL_GPL(clk_pll_vote_ops);

static void
clk_pll_set_fsm_mode(struct clk_pll *pll, struct regmap *regmap)
{
	u32 val;
	u32 mask;

	/* De-assert reset to FSM */
	regmap_update_bits(regmap, pll->mode_reg, PLL_VOTE_FSM_RESET, 0);

	/* Program bias count and lock count */
	val = 1 << PLL_BIAS_COUNT_SHIFT;
	mask = PLL_BIAS_COUNT_MASK << PLL_BIAS_COUNT_SHIFT;
	mask |= PLL_LOCK_COUNT_MASK << PLL_LOCK_COUNT_SHIFT;
	regmap_update_bits(regmap, pll->mode_reg, mask, val);

	/* Enable PLL FSM voting */
	regmap_update_bits(regmap, pll->mode_reg, PLL_VOTE_FSM_ENA,
		PLL_VOTE_FSM_ENA);
}

static void clk_pll_configure(struct clk_pll *pll, struct regmap *regmap,
	const struct pll_config *config)
{
	u32 val;
	u32 mask;

	regmap_write(regmap, pll->l_reg, config->l);
	regmap_write(regmap, pll->m_reg, config->m);
	regmap_write(regmap, pll->n_reg, config->n);

	val = config->vco_val;
	val |= config->pre_div_val;
	val |= config->post_div_val;
	val |= config->mn_ena_mask;
	val |= config->main_output_mask;
	val |= config->aux_output_mask;

	mask = config->vco_mask;
	mask |= config->pre_div_mask;
	mask |= config->post_div_mask;
	mask |= config->mn_ena_mask;
	mask |= config->main_output_mask;
	mask |= config->aux_output_mask;

	regmap_update_bits(regmap, pll->config_reg, mask, val);
}

void clk_pll_configure_sr_hpm_lp(struct clk_pll *pll, struct regmap *regmap,
		const struct pll_config *config, bool fsm_mode)
{
	clk_pll_configure(pll, regmap, config);
	if (fsm_mode)
		clk_pll_set_fsm_mode(pll, regmap);
}
EXPORT_SYMBOL_GPL(clk_pll_configure_sr_hpm_lp);