2 * linux/arch/arm/mach-tegra/platsmp.c
4 * Copyright (C) 2002 ARM Ltd.
7 * Copyright (C) 2009 Palm
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
14 #include <linux/init.h>
15 #include <linux/errno.h>
16 #include <linux/delay.h>
17 #include <linux/device.h>
18 #include <linux/jiffies.h>
19 #include <linux/smp.h>
21 #include <linux/clk/tegra.h>
23 #include <asm/cacheflush.h>
24 #include <asm/mach-types.h>
25 #include <asm/smp_scu.h>
26 #include <asm/smp_plat.h>
28 #include <mach/powergate.h>
37 extern void tegra_secondary_startup(void);
39 static cpumask_t tegra_cpu_init_mask;
41 #define EVP_CPU_RESET_VECTOR \
42 (IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE) + 0x100)
44 static void __cpuinit tegra_secondary_init(unsigned int cpu)
46 cpumask_set_cpu(cpu, &tegra_cpu_init_mask);
49 static int tegra20_power_up_cpu(unsigned int cpu)
51 /* Enable the CPU clock. */
52 tegra_enable_cpu_clock(cpu);
54 /* Clear flow controller CSR. */
55 flowctrl_write_cpu_csr(cpu, 0);
60 static int tegra30_power_up_cpu(unsigned int cpu)
63 unsigned long timeout;
65 pwrgateid = tegra_cpu_powergate_id(cpu);
70 * The power up sequence of cold boot CPU and warm boot CPU
73 * For warm boot CPU that was resumed from CPU hotplug, the
74 * power will be resumed automatically after un-halting the
75 * flow controller of the warm boot CPU. We need to wait for
76 * the confirmaiton that the CPU is powered then removing
78 * For cold boot CPU, do not wait. After the cold boot CPU be
79 * booted, it will run to tegra_secondary_init() and set
80 * tegra_cpu_init_mask which influences what tegra30_power_up_cpu()
83 if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
84 timeout = jiffies + msecs_to_jiffies(50);
86 if (!tegra_powergate_is_powered(pwrgateid))
89 } while (time_before(jiffies, timeout));
93 * The power status of the cold boot CPU is power gated as
94 * default. To power up the cold boot CPU, the power should
95 * be un-gated by un-toggling the power gate register
98 if (!tegra_powergate_is_powered(pwrgateid)) {
99 ret = tegra_powergate_power_on(pwrgateid);
103 /* Wait for the power to come up. */
104 timeout = jiffies + msecs_to_jiffies(100);
105 while (tegra_powergate_is_powered(pwrgateid)) {
106 if (time_after(jiffies, timeout))
113 /* CPU partition is powered. Enable the CPU clock. */
114 tegra_enable_cpu_clock(cpu);
117 /* Remove I/O clamps. */
118 ret = tegra_powergate_remove_clamping(pwrgateid);
121 /* Clear flow controller CSR. */
122 flowctrl_write_cpu_csr(cpu, 0);
127 static int __cpuinit tegra_boot_secondary(unsigned int cpu, struct task_struct *idle)
131 cpu = cpu_logical_map(cpu);
134 * Force the CPU into reset. The CPU must remain in reset when the
135 * flow controller state is cleared (which will cause the flow
136 * controller to stop driving reset if the CPU has been power-gated
137 * via the flow controller). This will have no effect on first boot
138 * of the CPU since it should already be in reset.
140 tegra_put_cpu_in_reset(cpu);
143 * Unhalt the CPU. If the flow controller was used to power-gate the
144 * CPU this will cause the flow controller to stop driving reset.
145 * The CPU will remain in reset because the clock and reset block
146 * is now driving reset.
148 flowctrl_write_cpu_halt(cpu, 0);
150 switch (tegra_chip_id) {
152 status = tegra20_power_up_cpu(cpu);
155 status = tegra30_power_up_cpu(cpu);
165 /* Take the CPU out of reset. */
166 tegra_cpu_out_of_reset(cpu);
171 static void __init tegra_smp_prepare_cpus(unsigned int max_cpus)
173 /* Always mark the boot CPU (CPU0) as initialized. */
174 cpumask_set_cpu(0, &tegra_cpu_init_mask);
176 if (scu_a9_has_base())
177 scu_enable(IO_ADDRESS(scu_a9_get_base()));
180 struct smp_operations tegra_smp_ops __initdata = {
181 .smp_prepare_cpus = tegra_smp_prepare_cpus,
182 .smp_secondary_init = tegra_secondary_init,
183 .smp_boot_secondary = tegra_boot_secondary,
184 #ifdef CONFIG_HOTPLUG_CPU
185 .cpu_kill = tegra_cpu_kill,
186 .cpu_die = tegra_cpu_die,
187 .cpu_disable = tegra_cpu_disable,