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 "omap-wakeupgen.h" 23 #include "common.h" 24 #include "powerdomain.h" 25 26 /* 27 * platform-specific code to shutdown a CPU 28 * Called with IRQs disabled 29 */ 30 void __ref omap4_cpu_die(unsigned int cpu) 31 { 32 unsigned int boot_cpu = 0; 33 void __iomem *base = omap_get_wakeupgen_base(); 34 35 /* 36 * we're ready for shutdown now, so do it 37 */ 38 if (omap_secure_apis_support()) { 39 if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0) 40 pr_err("Secure clear status failed\n"); 41 } else { 42 writel_relaxed(0, base + OMAP_AUX_CORE_BOOT_0); 43 } 44 45 46 for (;;) { 47 /* 48 * Enter into low power state 49 */ 50 omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF); 51 52 if (omap_secure_apis_support()) 53 boot_cpu = omap_read_auxcoreboot0(); 54 else 55 boot_cpu = 56 readl_relaxed(base + OMAP_AUX_CORE_BOOT_0) >> 5; 57 58 if (boot_cpu == smp_processor_id()) { 59 /* 60 * OK, proper wakeup, we're done 61 */ 62 break; 63 } 64 pr_debug("CPU%u: spurious wakeup call\n", cpu); 65 } 66 } 67