1 /*
2  * OMAP4 SMP cpu-hotplug support
3  *
4  * Copyright (C) 2010 Texas Instruments, Inc.
5  * Author:
6  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
7  *
8  * Platform file needed for the OMAP4 SMP. This file is based on arm
9  * realview smp platform.
10  * Copyright (c) 2002 ARM Limited.
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/smp.h>
20 #include <linux/io.h>
21 
22 #include <asm/cacheflush.h>
23 #include "omap-wakeupgen.h"
24 
25 #include "common.h"
26 
27 #include "powerdomain.h"
28 
29 /*
30  * platform-specific code to shutdown a CPU
31  * Called with IRQs disabled
32  */
33 void __ref omap4_cpu_die(unsigned int cpu)
34 {
35 	unsigned int boot_cpu = 0;
36 	void __iomem *base = omap_get_wakeupgen_base();
37 
38 	flush_cache_all();
39 	dsb();
40 
41 	/*
42 	 * we're ready for shutdown now, so do it
43 	 */
44 	if (omap_secure_apis_support()) {
45 		if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0)
46 			pr_err("Secure clear status failed\n");
47 	} else {
48 		__raw_writel(0, base + OMAP_AUX_CORE_BOOT_0);
49 	}
50 
51 
52 	for (;;) {
53 		/*
54 		 * Enter into low power state
55 		 */
56 		omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF);
57 
58 		if (omap_secure_apis_support())
59 			boot_cpu = omap_read_auxcoreboot0();
60 		else
61 			boot_cpu =
62 				__raw_readl(base + OMAP_AUX_CORE_BOOT_0) >> 5;
63 
64 		if (boot_cpu == smp_processor_id()) {
65 			/*
66 			 * OK, proper wakeup, we're done
67 			 */
68 			break;
69 		}
70 		pr_debug("CPU%u: spurious wakeup call\n", cpu);
71 	}
72 }
73