1 /*
2  * PPC476 board specific routines
3  *
4  * Copyright 2010 Torez Smith, IBM Corporation.
5  *
6  * Based on earlier code:
7  *    Matt Porter <mporter@kernel.crashing.org>
8  *    Copyright 2002-2005 MontaVista Software Inc.
9  *
10  *    Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
11  *    Copyright (c) 2003-2005 Zultys Technologies
12  *
13  *    Rewritten and ported to the merged powerpc tree:
14  *    Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
15  *
16  * This program is free software; you can redistribute  it and/or modify it
17  * under  the terms of  the GNU General  Public License as published by the
18  * Free Software Foundation;  either version 2 of the  License, or (at your
19  * option) any later version.
20  */
21 
22 #include <linux/init.h>
23 #include <linux/of_platform.h>
24 #include <linux/rtc.h>
25 
26 #include <asm/machdep.h>
27 #include <asm/prom.h>
28 #include <asm/udbg.h>
29 #include <asm/time.h>
30 #include <asm/uic.h>
31 #include <asm/ppc4xx.h>
32 #include <asm/mpic.h>
33 #include <asm/mmu.h>
34 
35 static const struct of_device_id iss4xx_of_bus[] __initconst = {
36 	{ .compatible = "ibm,plb4", },
37 	{ .compatible = "ibm,plb6", },
38 	{ .compatible = "ibm,opb", },
39 	{ .compatible = "ibm,ebc", },
40 	{},
41 };
42 
43 static int __init iss4xx_device_probe(void)
44 {
45 	of_platform_bus_probe(NULL, iss4xx_of_bus, NULL);
46 	of_instantiate_rtc();
47 
48 	return 0;
49 }
50 machine_device_initcall(iss4xx, iss4xx_device_probe);
51 
52 /* We can have either UICs or MPICs */
53 static void __init iss4xx_init_irq(void)
54 {
55 	struct device_node *np;
56 
57 	/* Find top level interrupt controller */
58 	for_each_node_with_property(np, "interrupt-controller") {
59 		if (of_get_property(np, "interrupts", NULL) == NULL)
60 			break;
61 	}
62 	if (np == NULL)
63 		panic("Can't find top level interrupt controller");
64 
65 	/* Check type and do appropriate initialization */
66 	if (of_device_is_compatible(np, "ibm,uic")) {
67 		uic_init_tree();
68 		ppc_md.get_irq = uic_get_irq;
69 #ifdef CONFIG_MPIC
70 	} else if (of_device_is_compatible(np, "chrp,open-pic")) {
71 		/* The MPIC driver will get everything it needs from the
72 		 * device-tree, just pass 0 to all arguments
73 		 */
74 		struct mpic *mpic = mpic_alloc(np, 0, MPIC_NO_RESET, 0, 0, " MPIC     ");
75 		BUG_ON(mpic == NULL);
76 		mpic_init(mpic);
77 		ppc_md.get_irq = mpic_get_irq;
78 #endif
79 	} else
80 		panic("Unrecognized top level interrupt controller");
81 }
82 
83 #ifdef CONFIG_SMP
84 static void smp_iss4xx_setup_cpu(int cpu)
85 {
86 	mpic_setup_this_cpu();
87 }
88 
89 static int smp_iss4xx_kick_cpu(int cpu)
90 {
91 	struct device_node *cpunode = of_get_cpu_node(cpu, NULL);
92 	const u64 *spin_table_addr_prop;
93 	u32 *spin_table;
94 	extern void start_secondary_47x(void);
95 
96 	BUG_ON(cpunode == NULL);
97 
98 	/* Assume spin table. We could test for the enable-method in
99 	 * the device-tree but currently there's little point as it's
100 	 * our only supported method
101 	 */
102 	spin_table_addr_prop = of_get_property(cpunode, "cpu-release-addr",
103 					       NULL);
104 	if (spin_table_addr_prop == NULL) {
105 		pr_err("CPU%d: Can't start, missing cpu-release-addr !\n", cpu);
106 		return -ENOENT;
107 	}
108 
109 	/* Assume it's mapped as part of the linear mapping. This is a bit
110 	 * fishy but will work fine for now
111 	 */
112 	spin_table = (u32 *)__va(*spin_table_addr_prop);
113 	pr_debug("CPU%d: Spin table mapped at %p\n", cpu, spin_table);
114 
115 	spin_table[3] = cpu;
116 	smp_wmb();
117 	spin_table[1] = __pa(start_secondary_47x);
118 	mb();
119 
120 	return 0;
121 }
122 
123 static struct smp_ops_t iss_smp_ops = {
124 	.probe		= smp_mpic_probe,
125 	.message_pass	= smp_mpic_message_pass,
126 	.setup_cpu	= smp_iss4xx_setup_cpu,
127 	.kick_cpu	= smp_iss4xx_kick_cpu,
128 	.give_timebase	= smp_generic_give_timebase,
129 	.take_timebase	= smp_generic_take_timebase,
130 };
131 
132 static void __init iss4xx_smp_init(void)
133 {
134 	if (mmu_has_feature(MMU_FTR_TYPE_47x))
135 		smp_ops = &iss_smp_ops;
136 }
137 
138 #else /* CONFIG_SMP */
139 static void __init iss4xx_smp_init(void) { }
140 #endif /* CONFIG_SMP */
141 
142 static void __init iss4xx_setup_arch(void)
143 {
144 	iss4xx_smp_init();
145 }
146 
147 /*
148  * Called very early, MMU is off, device-tree isn't unflattened
149  */
150 static int __init iss4xx_probe(void)
151 {
152 	unsigned long root = of_get_flat_dt_root();
153 
154 	if (!of_flat_dt_is_compatible(root, "ibm,iss-4xx"))
155 		return 0;
156 
157 	return 1;
158 }
159 
160 define_machine(iss4xx) {
161 	.name			= "ISS-4xx",
162 	.probe			= iss4xx_probe,
163 	.progress		= udbg_progress,
164 	.init_IRQ		= iss4xx_init_irq,
165 	.setup_arch		= iss4xx_setup_arch,
166 	.restart		= ppc4xx_reset_system,
167 	.calibrate_decr		= generic_calibrate_decr,
168 };
169