xref: /openbmc/linux/arch/arm/mach-ux500/cpu-db8500.c (revision 2a598d0b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2008-2009 ST-Ericsson SA
4  *
5  * Author: Srinidhi KASAGAR <srinidhi.kasagar@stericsson.com>
6  */
7 #include <linux/types.h>
8 #include <linux/init.h>
9 #include <linux/device.h>
10 #include <linux/amba/bus.h>
11 #include <linux/interrupt.h>
12 #include <linux/irq.h>
13 #include <linux/irqchip.h>
14 #include <linux/irqchip/arm-gic.h>
15 #include <linux/mfd/dbx500-prcmu.h>
16 #include <linux/platform_data/arm-ux500-pm.h>
17 #include <linux/platform_device.h>
18 #include <linux/io.h>
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21 #include <linux/of_platform.h>
22 #include <linux/regulator/machine.h>
23 
24 #include <asm/outercache.h>
25 #include <asm/hardware/cache-l2x0.h>
26 #include <asm/mach/map.h>
27 #include <asm/mach/arch.h>
28 
29 #include "pm_domains.h"
30 
31 static int __init ux500_l2x0_unlock(void)
32 {
33 	int i;
34 	struct device_node *np;
35 	void __iomem *l2x0_base;
36 
37 	np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache");
38 	l2x0_base = of_iomap(np, 0);
39 	of_node_put(np);
40 	if (!l2x0_base)
41 		return -ENODEV;
42 
43 	/*
44 	 * Unlock Data and Instruction Lock if locked. Ux500 U-Boot versions
45 	 * apparently locks both caches before jumping to the kernel. The
46 	 * l2x0 core will not touch the unlock registers if the l2x0 is
47 	 * already enabled, so we do it right here instead. The PL310 has
48 	 * 8 sets of registers, one per possible CPU.
49 	 */
50 	for (i = 0; i < 8; i++) {
51 		writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_D_BASE +
52 			       i * L2X0_LOCKDOWN_STRIDE);
53 		writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_I_BASE +
54 			       i * L2X0_LOCKDOWN_STRIDE);
55 	}
56 	iounmap(l2x0_base);
57 	return 0;
58 }
59 
60 static void ux500_l2c310_write_sec(unsigned long val, unsigned reg)
61 {
62 	/*
63 	 * We can't write to secure registers as we are in non-secure
64 	 * mode, until we have some SMI service available.
65 	 */
66 }
67 
68 /*
69  * FIXME: Should we set up the GPIO domain here?
70  *
71  * The problem is that we cannot put the interrupt resources into the platform
72  * device until the irqdomain has been added. Right now, we set the GIC interrupt
73  * domain from init_irq(), then load the gpio driver from
74  * core_initcall(nmk_gpio_init) and add the platform devices from
75  * arch_initcall(customize_machine).
76  *
77  * This feels fragile because it depends on the gpio device getting probed
78  * _before_ any device uses the gpio interrupts.
79 */
80 static void __init ux500_init_irq(void)
81 {
82 	struct device_node *np;
83 	struct resource r;
84 
85 	irqchip_init();
86 	prcmu_early_init();
87 	np = of_find_compatible_node(NULL, NULL, "stericsson,db8500-prcmu");
88 	of_address_to_resource(np, 0, &r);
89 	of_node_put(np);
90 	if (!r.start) {
91 		pr_err("could not find PRCMU base resource\n");
92 		return;
93 	}
94 	ux500_pm_init(r.start, r.end-r.start);
95 
96 	/* Unlock before init */
97 	ux500_l2x0_unlock();
98 	outer_cache.write_sec = ux500_l2c310_write_sec;
99 }
100 
101 static void ux500_restart(enum reboot_mode mode, const char *cmd)
102 {
103 	local_irq_disable();
104 	local_fiq_disable();
105 
106 	prcmu_system_reset(0);
107 }
108 
109 static const struct of_device_id u8500_local_bus_nodes[] = {
110 	/* only create devices below soc node */
111 	{ .compatible = "stericsson,db8500", },
112 	{ .compatible = "simple-bus"},
113 	{ },
114 };
115 
116 static void __init u8500_init_machine(void)
117 {
118 	/* Initialize ux500 power domains */
119 	ux500_pm_domains_init();
120 
121 	of_platform_populate(NULL, u8500_local_bus_nodes,
122 			     NULL, NULL);
123 }
124 
125 static const char * stericsson_dt_platform_compat[] = {
126 	"st-ericsson,u8500",
127 	"st-ericsson,u9500",
128 	NULL,
129 };
130 
131 DT_MACHINE_START(U8500_DT, "ST-Ericsson Ux5x0 platform (Device Tree Support)")
132 	.l2c_aux_val    = 0,
133 	.l2c_aux_mask	= ~0,
134 	.init_irq	= ux500_init_irq,
135 	.init_machine	= u8500_init_machine,
136 	.dt_compat      = stericsson_dt_platform_compat,
137 	.restart        = ux500_restart,
138 MACHINE_END
139