aboutsummaryrefslogtreecommitdiff
path: root/drivers/cpufreq/ti-cpufreq.c
blob: a7b5658c04609dc57d66a4049af55a25e157ee02 (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
/*
 * TI CPUFreq/OPP hw-supported driver
 *
 * Copyright (C) 2016-2017 Texas Instruments, Inc.
 *	 Dave Gerlach <d-gerlach@ti.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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/cpu.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/pm_opp.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#define REVISION_MASK				0xF
#define REVISION_SHIFT				28

#define AM33XX_800M_ARM_MPU_MAX_FREQ		0x1E2F
#define AM43XX_600M_ARM_MPU_MAX_FREQ		0xFFA

#define DRA7_EFUSE_HAS_OD_MPU_OPP		11
#define DRA7_EFUSE_HAS_HIGH_MPU_OPP		15
#define DRA7_EFUSE_HAS_ALL_MPU_OPP		23

#define DRA7_EFUSE_NOM_MPU_OPP			BIT(0)
#define DRA7_EFUSE_OD_MPU_OPP			BIT(1)
#define DRA7_EFUSE_HIGH_MPU_OPP			BIT(2)

#define VERSION_COUNT				2

struct ti_cpufreq_data;

struct ti_cpufreq_soc_data {
	unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data,
				     unsigned long efuse);
	unsigned long efuse_fallback;
	unsigned long efuse_offset;
	unsigned long efuse_mask;
	unsigned long efuse_shift;
	unsigned long rev_offset;
};

struct ti_cpufreq_data {
	struct device *cpu_dev;
	struct device_node *opp_node;
	struct regmap *syscon;
	const struct ti_cpufreq_soc_data *soc_data;
};

static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
				      unsigned long efuse)
{
	if (!efuse)
		efuse = opp_data->soc_data->efuse_fallback;
	/* AM335x and AM437x use "OPP disable" bits, so invert */
	return ~efuse;
}

static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data,
				      unsigned long efuse)
{
	unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP;

	/*
	 * The efuse on dra7 and am57 parts contains a specific
	 * value indicating the highest available OPP.
	 */

	switch (efuse) {
	case DRA7_EFUSE_HAS_ALL_MPU_OPP:
	case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
		calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
	case DRA7_EFUSE_HAS_OD_MPU_OPP:
		calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
	}

	return calculated_efuse;
}

static struct ti_cpufreq_soc_data am3x_soc_data = {
	.efuse_xlate = amx3_efuse_xlate,
	.efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
	.efuse_offset = 0x07fc,
	.efuse_mask = 0x1fff,
	.rev_offset = 0x600,
};

static struct ti_cpufreq_soc_data am4x_soc_data = {
	.efuse_xlate = amx3_efuse_xlate,
	.efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
	.efuse_offset = 0x0610,
	.efuse_mask = 0x3f,
	.rev_offset = 0x600,
};

static struct ti_cpufreq_soc_data dra7_soc_data = {
	.efuse_xlate = dra7_efuse_xlate,
	.efuse_offset = 0x020c,
	.efuse_mask = 0xf80000,
	.efuse_shift = 19,
	.rev_offset = 0x204,
};

/**
 * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
 * @opp_data: pointer to ti_cpufreq_data context
 * @efuse_value: Set to the value parsed from efuse
 *
 * Returns error code if efuse not read properly.
 */
static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
				u32 *efuse_value)
{
	struct device *dev = opp_data->cpu_dev;
	u32 efuse;
	int ret;

	ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
			  &efuse);
	if (ret) {
		dev_err(dev,
			"Failed to read the efuse value from syscon: %d\n",
			ret);
		return ret;
	}

	efuse = (efuse & opp_data->soc_data->efuse_mask);
	efuse >>= opp_data->soc_data->efuse_shift;

	*efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);

	return 0;
}

/**
 * ti_cpufreq_get_rev() - Parse and return rev value present on SoC
 * @opp_data: pointer to ti_cpufreq_data context
 * @revision_value: Set to the value parsed from revision register
 *
 * Returns error code if revision not read properly.
 */
static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
			      u32 *revision_value)
{
	struct device *dev = opp_data->cpu_dev;
	u32 revision;
	int ret;

	ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
			  &revision);
	if (ret) {
		dev_err(dev,
			"Failed to read the revision number from syscon: %d\n",
			ret);
		return ret;
	}

	*revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);

	return 0;
}

static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
{
	struct device *dev = opp_data->cpu_dev;
	struct device_node *np = opp_data->opp_node;

	opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
							"syscon");
	if (IS_ERR(opp_data->syscon)) {
		dev_err(dev,
			"\"syscon\" is missing, cannot use OPPv2 table.\n");
		return PTR_ERR(opp_data->syscon);
	}

	return 0;
}

static const struct of_device_id ti_cpufreq_of_match[] = {
	{ .compatible = "ti,am33xx", .data = &am3x_soc_data, },
	{ .compatible = "ti,am4372", .data = &am4x_soc_data, },
	{ .compatible = "ti,dra7", .data = &dra7_soc_data },
	{},
};

static int ti_cpufreq_init(void)
{
	u32 version[VERSION_COUNT];
	struct device_node *np;
	const struct of_device_id *match;
	struct ti_cpufreq_data *opp_data;
	int ret;

	np = of_find_node_by_path("/");
	match = of_match_node(ti_cpufreq_of_match, np);
	if (!match)
		return -ENODEV;

	opp_data = kzalloc(sizeof(*opp_data), GFP_KERNEL);
	if (!opp_data)
		return -ENOMEM;

	opp_data->soc_data = match->data;

	opp_data->cpu_dev = get_cpu_device(0);
	if (!opp_data->cpu_dev) {
		pr_err("%s: Failed to get device for CPU0\n", __func__);
		return -ENODEV;
	}

	opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
	if (!opp_data->opp_node) {
		dev_info(opp_data->cpu_dev,
			 "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
		goto register_cpufreq_dt;
	}

	ret = ti_cpufreq_setup_syscon_register(opp_data);
	if (ret)
		goto fail_put_node;

	/*
	 * OPPs determine whether or not they are supported based on
	 * two metrics:
	 *	0 - SoC Revision
	 *	1 - eFuse value
	 */
	ret = ti_cpufreq_get_rev(opp_data, &version[0]);
	if (ret)
		goto fail_put_node;

	ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
	if (ret)
		goto fail_put_node;

	of_node_put(opp_data->opp_node);

	ret = PTR_ERR_OR_ZERO(dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
							  version, VERSION_COUNT));
	if (ret) {
		dev_err(opp_data->cpu_dev,
			"Failed to set supported hardware\n");
		goto fail_put_node;
	}

register_cpufreq_dt:
	platform_device_register_simple("cpufreq-dt", -1, NULL, 0);

	return 0;

fail_put_node:
	of_node_put(opp_data->opp_node);

	return ret;
}
device_initcall(ti_cpufreq_init);