summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-tegra/powergate.c
blob: 15d506501cccbb64dc25e5a1178bd91d40e94901 (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
/*
 * drivers/powergate/tegra-powergate.c
 *
 * Copyright (c) 2010 Google, Inc
 *
 * Author:
 *	Colin Cross <ccross@google.com>
 *
 * 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/clk.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>

#include <mach/clk.h>
#include <mach/iomap.h>
#include <mach/powergate.h>

#include "fuse.h"

#define PWRGATE_TOGGLE		0x30
#define  PWRGATE_TOGGLE_START	(1 << 8)

#define REMOVE_CLAMPING		0x34

#define PWRGATE_STATUS		0x38

static int tegra_num_powerdomains;
static int tegra_num_cpu_domains;
static u8 *tegra_cpu_domains;
static u8 tegra30_cpu_domains[] = {
	TEGRA_POWERGATE_CPU0,
	TEGRA_POWERGATE_CPU1,
	TEGRA_POWERGATE_CPU2,
	TEGRA_POWERGATE_CPU3,
};

static DEFINE_SPINLOCK(tegra_powergate_lock);

static void __iomem *pmc = IO_ADDRESS(TEGRA_PMC_BASE);

static u32 pmc_read(unsigned long reg)
{
	return readl(pmc + reg);
}

static void pmc_write(u32 val, unsigned long reg)
{
	writel(val, pmc + reg);
}

static int tegra_powergate_set(int id, bool new_state)
{
	bool status;
	unsigned long flags;

	spin_lock_irqsave(&tegra_powergate_lock, flags);

	status = pmc_read(PWRGATE_STATUS) & (1 << id);

	if (status == new_state) {
		spin_unlock_irqrestore(&tegra_powergate_lock, flags);
		return -EINVAL;
	}

	pmc_write(PWRGATE_TOGGLE_START | id, PWRGATE_TOGGLE);

	spin_unlock_irqrestore(&tegra_powergate_lock, flags);

	return 0;
}

int tegra_powergate_power_on(int id)
{
	if (id < 0 || id >= tegra_num_powerdomains)
		return -EINVAL;

	return tegra_powergate_set(id, true);
}

int tegra_powergate_power_off(int id)
{
	if (id < 0 || id >= tegra_num_powerdomains)
		return -EINVAL;

	return tegra_powergate_set(id, false);
}

int tegra_powergate_is_powered(int id)
{
	u32 status;

	if (id < 0 || id >= tegra_num_powerdomains)
		return -EINVAL;

	status = pmc_read(PWRGATE_STATUS) & (1 << id);
	return !!status;
}

int tegra_powergate_remove_clamping(int id)
{
	u32 mask;

	if (id < 0 || id >= tegra_num_powerdomains)
		return -EINVAL;

	/*
	 * Tegra 2 has a bug where PCIE and VDE clamping masks are
	 * swapped relatively to the partition ids
	 */
	if (id ==  TEGRA_POWERGATE_VDEC)
		mask = (1 << TEGRA_POWERGATE_PCIE);
	else if	(id == TEGRA_POWERGATE_PCIE)
		mask = (1 << TEGRA_POWERGATE_VDEC);
	else
		mask = (1 << id);

	pmc_write(mask, REMOVE_CLAMPING);

	return 0;
}

/* Must be called with clk disabled, and returns with clk enabled */
int tegra_powergate_sequence_power_up(int id, struct clk *clk)
{
	int ret;

	tegra_periph_reset_assert(clk);

	ret = tegra_powergate_power_on(id);
	if (ret)
		goto err_power;

	ret = clk_prepare_enable(clk);
	if (ret)
		goto err_clk;

	udelay(10);

	ret = tegra_powergate_remove_clamping(id);
	if (ret)
		goto err_clamp;

	udelay(10);
	tegra_periph_reset_deassert(clk);

	return 0;

err_clamp:
	clk_disable_unprepare(clk);
err_clk:
	tegra_powergate_power_off(id);
err_power:
	return ret;
}

int tegra_cpu_powergate_id(int cpuid)
{
	if (cpuid > 0 && cpuid < tegra_num_cpu_domains)
		return tegra_cpu_domains[cpuid];

	return -EINVAL;
}

int __init tegra_powergate_init(void)
{
	switch (tegra_chip_id) {
	case TEGRA20:
		tegra_num_powerdomains = 7;
		break;
	case TEGRA30:
		tegra_num_powerdomains = 14;
		tegra_num_cpu_domains = 4;
		tegra_cpu_domains = tegra30_cpu_domains;
		break;
	default:
		/* Unknown Tegra variant. Disable powergating */
		tegra_num_powerdomains = 0;
		break;
	}

	return 0;
}

#ifdef CONFIG_DEBUG_FS

static const char * const powergate_name[] = {
	[TEGRA_POWERGATE_CPU]	= "cpu",
	[TEGRA_POWERGATE_3D]	= "3d",
	[TEGRA_POWERGATE_VENC]	= "venc",
	[TEGRA_POWERGATE_VDEC]	= "vdec",
	[TEGRA_POWERGATE_PCIE]	= "pcie",
	[TEGRA_POWERGATE_L2]	= "l2",
	[TEGRA_POWERGATE_MPE]	= "mpe",
};

static int powergate_show(struct seq_file *s, void *data)
{
	int i;

	seq_printf(s, " powergate powered\n");
	seq_printf(s, "------------------\n");

	for (i = 0; i < tegra_num_powerdomains; i++)
		seq_printf(s, " %9s %7s\n", powergate_name[i],
			tegra_powergate_is_powered(i) ? "yes" : "no");
	return 0;
}

static int powergate_open(struct inode *inode, struct file *file)
{
	return single_open(file, powergate_show, inode->i_private);
}

static const struct file_operations powergate_fops = {
	.open		= powergate_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

int __init tegra_powergate_debugfs_init(void)
{
	struct dentry *d;
	int err = -ENOMEM;

	d = debugfs_create_file("powergate", S_IRUGO, NULL, NULL,
		&powergate_fops);
	if (!d)
		return -ENOMEM;

	return err;
}

#endif
OpenPOWER on IntegriCloud