summaryrefslogtreecommitdiffstats
path: root/drivers/clk/spear/clk-aux-synth.c
blob: f271c350ef9404838fcaa6502db28cd1db5a744c (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
/*
 * Copyright (C) 2012 ST Microelectronics
 * Viresh Kumar <vireshk@kernel.org>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 *
 * Auxiliary Synthesizer clock implementation
 */

#define pr_fmt(fmt) "clk-aux-synth: " fmt

#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include "clk.h"

/*
 * DOC: Auxiliary Synthesizer clock
 *
 * Aux synth gives rate for different values of eq, x and y
 *
 * Fout from synthesizer can be given from two equations:
 * Fout1 = (Fin * X/Y)/2		EQ1
 * Fout2 = Fin * X/Y			EQ2
 */

#define to_clk_aux(_hw) container_of(_hw, struct clk_aux, hw)

static struct aux_clk_masks default_aux_masks = {
	.eq_sel_mask = AUX_EQ_SEL_MASK,
	.eq_sel_shift = AUX_EQ_SEL_SHIFT,
	.eq1_mask = AUX_EQ1_SEL,
	.eq2_mask = AUX_EQ2_SEL,
	.xscale_sel_mask = AUX_XSCALE_MASK,
	.xscale_sel_shift = AUX_XSCALE_SHIFT,
	.yscale_sel_mask = AUX_YSCALE_MASK,
	.yscale_sel_shift = AUX_YSCALE_SHIFT,
	.enable_bit = AUX_SYNT_ENB,
};

static unsigned long aux_calc_rate(struct clk_hw *hw, unsigned long prate,
		int index)
{
	struct clk_aux *aux = to_clk_aux(hw);
	struct aux_rate_tbl *rtbl = aux->rtbl;
	u8 eq = rtbl[index].eq ? 1 : 2;

	return (((prate / 10000) * rtbl[index].xscale) /
			(rtbl[index].yscale * eq)) * 10000;
}

static long clk_aux_round_rate(struct clk_hw *hw, unsigned long drate,
		unsigned long *prate)
{
	struct clk_aux *aux = to_clk_aux(hw);
	int unused;

	return clk_round_rate_index(hw, drate, *prate, aux_calc_rate,
			aux->rtbl_cnt, &unused);
}

static unsigned long clk_aux_recalc_rate(struct clk_hw *hw,
		unsigned long parent_rate)
{
	struct clk_aux *aux = to_clk_aux(hw);
	unsigned int num = 1, den = 1, val, eqn;
	unsigned long flags = 0;

	if (aux->lock)
		spin_lock_irqsave(aux->lock, flags);

	val = readl_relaxed(aux->reg);

	if (aux->lock)
		spin_unlock_irqrestore(aux->lock, flags);

	eqn = (val >> aux->masks->eq_sel_shift) & aux->masks->eq_sel_mask;
	if (eqn == aux->masks->eq1_mask)
		den = 2;

	/* calculate numerator */
	num = (val >> aux->masks->xscale_sel_shift) &
		aux->masks->xscale_sel_mask;

	/* calculate denominator */
	den *= (val >> aux->masks->yscale_sel_shift) &
		aux->masks->yscale_sel_mask;

	if (!den)
		return 0;

	return (((parent_rate / 10000) * num) / den) * 10000;
}

/* Configures new clock rate of aux */
static int clk_aux_set_rate(struct clk_hw *hw, unsigned long drate,
				unsigned long prate)
{
	struct clk_aux *aux = to_clk_aux(hw);
	struct aux_rate_tbl *rtbl = aux->rtbl;
	unsigned long val, flags = 0;
	int i;

	clk_round_rate_index(hw, drate, prate, aux_calc_rate, aux->rtbl_cnt,
			&i);

	if (aux->lock)
		spin_lock_irqsave(aux->lock, flags);

	val = readl_relaxed(aux->reg) &
		~(aux->masks->eq_sel_mask << aux->masks->eq_sel_shift);
	val |= (rtbl[i].eq & aux->masks->eq_sel_mask) <<
		aux->masks->eq_sel_shift;
	val &= ~(aux->masks->xscale_sel_mask << aux->masks->xscale_sel_shift);
	val |= (rtbl[i].xscale & aux->masks->xscale_sel_mask) <<
		aux->masks->xscale_sel_shift;
	val &= ~(aux->masks->yscale_sel_mask << aux->masks->yscale_sel_shift);
	val |= (rtbl[i].yscale & aux->masks->yscale_sel_mask) <<
		aux->masks->yscale_sel_shift;
	writel_relaxed(val, aux->reg);

	if (aux->lock)
		spin_unlock_irqrestore(aux->lock, flags);

	return 0;
}

static struct clk_ops clk_aux_ops = {
	.recalc_rate = clk_aux_recalc_rate,
	.round_rate = clk_aux_round_rate,
	.set_rate = clk_aux_set_rate,
};

struct clk *clk_register_aux(const char *aux_name, const char *gate_name,
		const char *parent_name, unsigned long flags, void __iomem *reg,
		struct aux_clk_masks *masks, struct aux_rate_tbl *rtbl,
		u8 rtbl_cnt, spinlock_t *lock, struct clk **gate_clk)
{
	struct clk_aux *aux;
	struct clk_init_data init;
	struct clk *clk;

	if (!aux_name || !parent_name || !reg || !rtbl || !rtbl_cnt) {
		pr_err("Invalid arguments passed");
		return ERR_PTR(-EINVAL);
	}

	aux = kzalloc(sizeof(*aux), GFP_KERNEL);
	if (!aux) {
		pr_err("could not allocate aux clk\n");
		return ERR_PTR(-ENOMEM);
	}

	/* struct clk_aux assignments */
	if (!masks)
		aux->masks = &default_aux_masks;
	else
		aux->masks = masks;

	aux->reg = reg;
	aux->rtbl = rtbl;
	aux->rtbl_cnt = rtbl_cnt;
	aux->lock = lock;
	aux->hw.init = &init;

	init.name = aux_name;
	init.ops = &clk_aux_ops;
	init.flags = flags;
	init.parent_names = &parent_name;
	init.num_parents = 1;

	clk = clk_register(NULL, &aux->hw);
	if (IS_ERR_OR_NULL(clk))
		goto free_aux;

	if (gate_name) {
		struct clk *tgate_clk;

		tgate_clk = clk_register_gate(NULL, gate_name, aux_name,
				CLK_SET_RATE_PARENT, reg,
				aux->masks->enable_bit, 0, lock);
		if (IS_ERR_OR_NULL(tgate_clk))
			goto free_aux;

		if (gate_clk)
			*gate_clk = tgate_clk;
	}

	return clk;

free_aux:
	kfree(aux);
	pr_err("clk register failed\n");

	return NULL;
}