xref: /openbmc/linux/arch/arm/mach-ux500/cpu-db8500.c (revision c4f7ac64)
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 "db8500-regs.h"
30 #include "pm_domains.h"
31 
32 static int __init ux500_l2x0_unlock(void)
33 {
34 	int i;
35 	struct device_node *np;
36 	void __iomem *l2x0_base;
37 
38 	np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache");
39 	l2x0_base = of_iomap(np, 0);
40 	of_node_put(np);
41 	if (!l2x0_base)
42 		return -ENODEV;
43 
44 	/*
45 	 * Unlock Data and Instruction Lock if locked. Ux500 U-Boot versions
46 	 * apparently locks both caches before jumping to the kernel. The
47 	 * l2x0 core will not touch the unlock registers if the l2x0 is
48 	 * already enabled, so we do it right here instead. The PL310 has
49 	 * 8 sets of registers, one per possible CPU.
50 	 */
51 	for (i = 0; i < 8; i++) {
52 		writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_D_BASE +
53 			       i * L2X0_LOCKDOWN_STRIDE);
54 		writel_relaxed(0x0, l2x0_base + L2X0_LOCKDOWN_WAY_I_BASE +
55 			       i * L2X0_LOCKDOWN_STRIDE);
56 	}
57 	iounmap(l2x0_base);
58 	return 0;
59 }
60 
61 static void ux500_l2c310_write_sec(unsigned long val, unsigned reg)
62 {
63 	/*
64 	 * We can't write to secure registers as we are in non-secure
65 	 * mode, until we have some SMI service available.
66 	 */
67 }
68 
69 /*
70  * FIXME: Should we set up the GPIO domain here?
71  *
72  * The problem is that we cannot put the interrupt resources into the platform
73  * device until the irqdomain has been added. Right now, we set the GIC interrupt
74  * domain from init_irq(), then load the gpio driver from
75  * core_initcall(nmk_gpio_init) and add the platform devices from
76  * arch_initcall(customize_machine).
77  *
78  * This feels fragile because it depends on the gpio device getting probed
79  * _before_ any device uses the gpio interrupts.
80 */
81 static void __init ux500_init_irq(void)
82 {
83 	struct device_node *np;
84 	struct resource r;
85 
86 	irqchip_init();
87 	prcmu_early_init();
88 	np = of_find_compatible_node(NULL, NULL, "stericsson,db8500-prcmu");
89 	of_address_to_resource(np, 0, &r);
90 	of_node_put(np);
91 	if (!r.start) {
92 		pr_err("could not find PRCMU base resource\n");
93 		return;
94 	}
95 	ux500_pm_init(r.start, r.end-r.start);
96 
97 	/* Unlock before init */
98 	ux500_l2x0_unlock();
99 	outer_cache.write_sec = ux500_l2c310_write_sec;
100 }
101 
102 static void ux500_restart(enum reboot_mode mode, const char *cmd)
103 {
104 	local_irq_disable();
105 	local_fiq_disable();
106 
107 	prcmu_system_reset(0);
108 }
109 
110 static const struct of_device_id u8500_local_bus_nodes[] = {
111 	/* only create devices below soc node */
112 	{ .compatible = "stericsson,db8500", },
113 	{ .compatible = "simple-bus"},
114 	{ },
115 };
116 
117 static void __init u8500_init_machine(void)
118 {
119 	/* Initialize ux500 power domains */
120 	ux500_pm_domains_init();
121 
122 	of_platform_populate(NULL, u8500_local_bus_nodes,
123 			     NULL, NULL);
124 }
125 
126 static const char * stericsson_dt_platform_compat[] = {
127 	"st-ericsson,u8500",
128 	"st-ericsson,u9500",
129 	NULL,
130 };
131 
132 DT_MACHINE_START(U8500_DT, "ST-Ericsson Ux5x0 platform (Device Tree Support)")
133 	.l2c_aux_val    = 0,
134 	.l2c_aux_mask	= ~0,
135 	.init_irq	= ux500_init_irq,
136 	.init_machine	= u8500_init_machine,
137 	.dt_compat      = stericsson_dt_platform_compat,
138 	.restart        = ux500_restart,
139 MACHINE_END
140