xref: /openbmc/linux/arch/arm/mach-mvebu/pmsu.c (revision f7777dcc)
1 /*
2  * Power Management Service Unit(PMSU) support for Armada 370/XP platforms.
3  *
4  * Copyright (C) 2012 Marvell
5  *
6  * Yehuda Yitschak <yehuday@marvell.com>
7  * Gregory Clement <gregory.clement@free-electrons.com>
8  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
9  *
10  * This file is licensed under the terms of the GNU General Public
11  * License version 2.  This program is licensed "as is" without any
12  * warranty of any kind, whether express or implied.
13  *
14  * The Armada 370 and Armada XP SOCs have a power management service
15  * unit which is responsible for powering down and waking up CPUs and
16  * other SOC units
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/init.h>
21 #include <linux/of_address.h>
22 #include <linux/io.h>
23 #include <linux/smp.h>
24 #include <asm/smp_plat.h>
25 
26 static void __iomem *pmsu_mp_base;
27 static void __iomem *pmsu_reset_base;
28 
29 #define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu)	((cpu * 0x100) + 0x24)
30 #define PMSU_RESET_CTL_OFFSET(cpu)		(cpu * 0x8)
31 
32 static struct of_device_id of_pmsu_table[] = {
33 	{.compatible = "marvell,armada-370-xp-pmsu"},
34 	{ /* end of list */ },
35 };
36 
37 #ifdef CONFIG_SMP
38 int armada_xp_boot_cpu(unsigned int cpu_id, void *boot_addr)
39 {
40 	int reg, hw_cpu;
41 
42 	if (!pmsu_mp_base || !pmsu_reset_base) {
43 		pr_warn("Can't boot CPU. PMSU is uninitialized\n");
44 		return 1;
45 	}
46 
47 	hw_cpu = cpu_logical_map(cpu_id);
48 
49 	writel(virt_to_phys(boot_addr), pmsu_mp_base +
50 			PMSU_BOOT_ADDR_REDIRECT_OFFSET(hw_cpu));
51 
52 	/* Release CPU from reset by clearing reset bit*/
53 	reg = readl(pmsu_reset_base + PMSU_RESET_CTL_OFFSET(hw_cpu));
54 	reg &= (~0x1);
55 	writel(reg, pmsu_reset_base + PMSU_RESET_CTL_OFFSET(hw_cpu));
56 
57 	return 0;
58 }
59 #endif
60 
61 int __init armada_370_xp_pmsu_init(void)
62 {
63 	struct device_node *np;
64 
65 	np = of_find_matching_node(NULL, of_pmsu_table);
66 	if (np) {
67 		pr_info("Initializing Power Management Service Unit\n");
68 		pmsu_mp_base = of_iomap(np, 0);
69 		pmsu_reset_base = of_iomap(np, 1);
70 		of_node_put(np);
71 	}
72 
73 	return 0;
74 }
75 
76 early_initcall(armada_370_xp_pmsu_init);
77