summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-tegra/platsmp.c
blob: 2c6b3d55213b49f16ee256548279b1742111bd20 (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
/*
 *  linux/arch/arm/mach-tegra/platsmp.c
 *
 *  Copyright (C) 2002 ARM Ltd.
 *  All Rights Reserved
 *
 *  Copyright (C) 2009 Palm
 *  All Rights Reserved
 *
 * 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.
 */
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/clk/tegra.h>

#include <asm/cacheflush.h>
#include <asm/mach-types.h>
#include <asm/smp_scu.h>
#include <asm/smp_plat.h>

#include <mach/powergate.h>

#include "fuse.h"
#include "flowctrl.h"
#include "reset.h"

#include "common.h"
#include "iomap.h"

extern void tegra_secondary_startup(void);

static cpumask_t tegra_cpu_init_mask;

#define EVP_CPU_RESET_VECTOR \
	(IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE) + 0x100)

static void __cpuinit tegra_secondary_init(unsigned int cpu)
{
	/*
	 * if any interrupts are already enabled for the primary
	 * core (e.g. timer irq), then they will not have been enabled
	 * for us: do so
	 */
	gic_secondary_init(0);

	cpumask_set_cpu(cpu, &tegra_cpu_init_mask);
}

static int tegra20_power_up_cpu(unsigned int cpu)
{
	/* Enable the CPU clock. */
	tegra_enable_cpu_clock(cpu);

	/* Clear flow controller CSR. */
	flowctrl_write_cpu_csr(cpu, 0);

	return 0;
}

static int tegra30_power_up_cpu(unsigned int cpu)
{
	int ret, pwrgateid;
	unsigned long timeout;

	pwrgateid = tegra_cpu_powergate_id(cpu);
	if (pwrgateid < 0)
		return pwrgateid;

	/*
	 * The power up sequence of cold boot CPU and warm boot CPU
	 * was different.
	 *
	 * For warm boot CPU that was resumed from CPU hotplug, the
	 * power will be resumed automatically after un-halting the
	 * flow controller of the warm boot CPU. We need to wait for
	 * the confirmaiton that the CPU is powered then removing
	 * the IO clamps.
	 * For cold boot CPU, do not wait. After the cold boot CPU be
	 * booted, it will run to tegra_secondary_init() and set
	 * tegra_cpu_init_mask which influences what tegra30_power_up_cpu()
	 * next time around.
	 */
	if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
		timeout = jiffies + msecs_to_jiffies(50);
		do {
			if (!tegra_powergate_is_powered(pwrgateid))
				goto remove_clamps;
			udelay(10);
		} while (time_before(jiffies, timeout));
	}

	/*
	 * The power status of the cold boot CPU is power gated as
	 * default. To power up the cold boot CPU, the power should
	 * be un-gated by un-toggling the power gate register
	 * manually.
	 */
	if (!tegra_powergate_is_powered(pwrgateid)) {
		ret = tegra_powergate_power_on(pwrgateid);
		if (ret)
			return ret;

		/* Wait for the power to come up. */
		timeout = jiffies + msecs_to_jiffies(100);
		while (tegra_powergate_is_powered(pwrgateid)) {
			if (time_after(jiffies, timeout))
				return -ETIMEDOUT;
			udelay(10);
		}
	}

remove_clamps:
	/* CPU partition is powered. Enable the CPU clock. */
	tegra_enable_cpu_clock(cpu);
	udelay(10);

	/* Remove I/O clamps. */
	ret = tegra_powergate_remove_clamping(pwrgateid);
	udelay(10);

	/* Clear flow controller CSR. */
	flowctrl_write_cpu_csr(cpu, 0);

	return 0;
}

static int __cpuinit tegra_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
	int status;

	cpu = cpu_logical_map(cpu);

	/*
	 * Force the CPU into reset. The CPU must remain in reset when the
	 * flow controller state is cleared (which will cause the flow
	 * controller to stop driving reset if the CPU has been power-gated
	 * via the flow controller). This will have no effect on first boot
	 * of the CPU since it should already be in reset.
	 */
	tegra_put_cpu_in_reset(cpu);

	/*
	 * Unhalt the CPU. If the flow controller was used to power-gate the
	 * CPU this will cause the flow controller to stop driving reset.
	 * The CPU will remain in reset because the clock and reset block
	 * is now driving reset.
	 */
	flowctrl_write_cpu_halt(cpu, 0);

	switch (tegra_chip_id) {
	case TEGRA20:
		status = tegra20_power_up_cpu(cpu);
		break;
	case TEGRA30:
		status = tegra30_power_up_cpu(cpu);
		break;
	default:
		status = -EINVAL;
		break;
	}

	if (status)
		goto done;

	/* Take the CPU out of reset. */
	tegra_cpu_out_of_reset(cpu);
done:
	return status;
}

static void __init tegra_smp_prepare_cpus(unsigned int max_cpus)
{
	/* Always mark the boot CPU (CPU0) as initialized. */
	cpumask_set_cpu(0, &tegra_cpu_init_mask);

	if (scu_a9_has_base())
		scu_enable(IO_ADDRESS(scu_a9_get_base()));
}

struct smp_operations tegra_smp_ops __initdata = {
	.smp_prepare_cpus	= tegra_smp_prepare_cpus,
	.smp_secondary_init	= tegra_secondary_init,
	.smp_boot_secondary	= tegra_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
	.cpu_kill		= tegra_cpu_kill,
	.cpu_die		= tegra_cpu_die,
	.cpu_disable		= tegra_cpu_disable,
#endif
};