summaryrefslogtreecommitdiff
path: root/drivers/clk/qcom/clk-rcg2.c
blob: 00f878a04d3f4847007101bc6a5c97ff5c2c060e (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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
/*
 * 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/export.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/regmap.h>

#include <asm/div64.h>

#include "clk-rcg.h"

#define CMD_REG			0x0
#define CMD_UPDATE		BIT(0)
#define CMD_ROOT_EN		BIT(1)
#define CMD_DIRTY_CFG		BIT(4)
#define CMD_DIRTY_N		BIT(5)
#define CMD_DIRTY_M		BIT(6)
#define CMD_DIRTY_D		BIT(7)
#define CMD_ROOT_OFF		BIT(31)

#define CFG_REG			0x4
#define CFG_SRC_DIV_SHIFT	0
#define CFG_SRC_SEL_SHIFT	8
#define CFG_SRC_SEL_MASK	(0x7 << CFG_SRC_SEL_SHIFT)
#define CFG_MODE_SHIFT		12
#define CFG_MODE_MASK		(0x3 << CFG_MODE_SHIFT)
#define CFG_MODE_DUAL_EDGE	(0x2 << CFG_MODE_SHIFT)

#define M_REG			0x8
#define N_REG			0xc
#define D_REG			0x10

static int clk_rcg2_is_enabled(struct clk_hw *hw)
{
	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
	u32 cmd;
	int ret;

	ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG, &cmd);
	if (ret)
		return ret;

	return (cmd & CMD_ROOT_OFF) != 0;
}

static u8 clk_rcg2_get_parent(struct clk_hw *hw)
{
	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
	int num_parents = __clk_get_num_parents(hw->clk);
	u32 cfg;
	int i, ret;

	ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, &cfg);
	if (ret)
		return ret;

	cfg &= CFG_SRC_SEL_MASK;
	cfg >>= CFG_SRC_SEL_SHIFT;

	for (i = 0; i < num_parents; i++)
		if (cfg == rcg->parent_map[i])
			return i;

	return -EINVAL;
}

static int update_config(struct clk_rcg2 *rcg)
{
	int count, ret;
	u32 cmd;
	struct clk_hw *hw = &rcg->clkr.hw;
	const char *name = __clk_get_name(hw->clk);

	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG,
				 CMD_UPDATE, CMD_UPDATE);
	if (ret)
		return ret;

	/* Wait for update to take effect */
	for (count = 500; count > 0; count--) {
		ret = regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CMD_REG, &cmd);
		if (ret)
			return ret;
		if (!(cmd & CMD_UPDATE))
			return 0;
		udelay(1);
	}

	WARN(1, "%s: rcg didn't update its configuration.", name);
	return 0;
}

static int clk_rcg2_set_parent(struct clk_hw *hw, u8 index)
{
	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
	int ret;

	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
				 CFG_SRC_SEL_MASK,
				 rcg->parent_map[index] << CFG_SRC_SEL_SHIFT);
	if (ret)
		return ret;

	return update_config(rcg);
}

/*
 * Calculate m/n:d rate
 *
 *          parent_rate     m
 *   rate = ----------- x  ---
 *            hid_div       n
 */
static unsigned long
calc_rate(unsigned long rate, u32 m, u32 n, u32 mode, u32 hid_div)
{
	if (hid_div) {
		rate *= 2;
		rate /= hid_div + 1;
	}

	if (mode) {
		u64 tmp = rate;
		tmp *= m;
		do_div(tmp, n);
		rate = tmp;
	}

	return rate;
}

static unsigned long
clk_rcg2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
{
	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
	u32 cfg, hid_div, m = 0, n = 0, mode = 0, mask;

	regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, &cfg);

	if (rcg->mnd_width) {
		mask = BIT(rcg->mnd_width) - 1;
		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + M_REG, &m);
		m &= mask;
		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + N_REG, &n);
		n =  ~n;
		n &= mask;
		n += m;
		mode = cfg & CFG_MODE_MASK;
		mode >>= CFG_MODE_SHIFT;
	}

	mask = BIT(rcg->hid_width) - 1;
	hid_div = cfg >> CFG_SRC_DIV_SHIFT;
	hid_div &= mask;

	return calc_rate(parent_rate, m, n, mode, hid_div);
}

static const
struct freq_tbl *find_freq(const struct freq_tbl *f, unsigned long rate)
{
	if (!f)
		return NULL;

	for (; f->freq; f++)
		if (rate <= f->freq)
			return f;

	return NULL;
}

static long _freq_tbl_determine_rate(struct clk_hw *hw,
		const struct freq_tbl *f, unsigned long rate,
		unsigned long *p_rate, struct clk **p)
{
	unsigned long clk_flags;

	f = find_freq(f, rate);
	if (!f)
		return -EINVAL;

	clk_flags = __clk_get_flags(hw->clk);
	*p = clk_get_parent_by_index(hw->clk, f->src);
	if (clk_flags & CLK_SET_RATE_PARENT) {
		if (f->pre_div) {
			rate /= 2;
			rate *= f->pre_div + 1;
		}

		if (f->n) {
			u64 tmp = rate;
			tmp = tmp * f->n;
			do_div(tmp, f->m);
			rate = tmp;
		}
	} else {
		rate =  __clk_get_rate(*p);
	}
	*p_rate = rate;

	return f->freq;
}

static long clk_rcg2_determine_rate(struct clk_hw *hw, unsigned long rate,
		unsigned long *p_rate, struct clk **p)
{
	struct clk_rcg2 *rcg = to_clk_rcg2(hw);

	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, rate, p_rate, p);
}

static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
{
	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
	const struct freq_tbl *f;
	u32 cfg, mask;
	int ret;

	f = find_freq(rcg->freq_tbl, rate);
	if (!f)
		return -EINVAL;

	if (rcg->mnd_width && f->n) {
		mask = BIT(rcg->mnd_width) - 1;
		ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + M_REG,
					 mask, f->m);
		if (ret)
			return ret;

		ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + N_REG,
					 mask, ~(f->n - f->m));
		if (ret)
			return ret;

		ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + D_REG,
					 mask, ~f->n);
		if (ret)
			return ret;
	}

	mask = BIT(rcg->hid_width) - 1;
	mask |= CFG_SRC_SEL_MASK | CFG_MODE_MASK;
	cfg = f->pre_div << CFG_SRC_DIV_SHIFT;
	cfg |= rcg->parent_map[f->src] << CFG_SRC_SEL_SHIFT;
	if (rcg->mnd_width && f->n)
		cfg |= CFG_MODE_DUAL_EDGE;
	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, mask,
			cfg);
	if (ret)
		return ret;

	return update_config(rcg);
}

static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
			    unsigned long parent_rate)
{
	return __clk_rcg2_set_rate(hw, rate);
}

static int clk_rcg2_set_rate_and_parent(struct clk_hw *hw,
		unsigned long rate, unsigned long parent_rate, u8 index)
{
	return __clk_rcg2_set_rate(hw, rate);
}

const struct clk_ops clk_rcg2_ops = {
	.is_enabled = clk_rcg2_is_enabled,
	.get_parent = clk_rcg2_get_parent,
	.set_parent = clk_rcg2_set_parent,
	.recalc_rate = clk_rcg2_recalc_rate,
	.determine_rate = clk_rcg2_determine_rate,
	.set_rate = clk_rcg2_set_rate,
	.set_rate_and_parent = clk_rcg2_set_rate_and_parent,
};
EXPORT_SYMBOL_GPL(clk_rcg2_ops);