1 /*
2 * Copyright (c) 2011 Picochip Ltd., Jamie Iles
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * All enquiries to support@picochip.com
9 */
10 #include <linux/delay.h>
11 #include <linux/irq.h>
12 #include <linux/irqdomain.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_irq.h>
16 #include <linux/of_platform.h>
17
18 #include <asm/mach/arch.h>
19 #include <asm/hardware/vic.h>
20 #include <asm/mach/map.h>
21
22 #include <mach/map.h>
23 #include <mach/picoxcell_soc.h>
24
25 #include "common.h"
26
27 #define WDT_CTRL_REG_EN_MASK (1 << 0)
28 #define WDT_CTRL_REG_OFFS (0x00)
29 #define WDT_TIMEOUT_REG_OFFS (0x04)
30 static void __iomem *wdt_regs;
31
32 /*
33 * The machine restart method can be called from an atomic context so we won't
34 * be able to ioremap the regs then.
35 */
picoxcell_setup_restart(void)36 static void picoxcell_setup_restart(void)
37 {
38 struct device_node *np = of_find_compatible_node(NULL, NULL,
39 "snps,dw-apb-wdg");
40 if (WARN(!np, "unable to setup watchdog restart"))
41 return;
42
43 wdt_regs = of_iomap(np, 0);
44 WARN(!wdt_regs, "failed to remap watchdog regs");
45 }
46
47 static struct map_desc io_map __initdata = {
48 .virtual = PHYS_TO_IO(PICOXCELL_PERIPH_BASE),
49 .pfn = __phys_to_pfn(PICOXCELL_PERIPH_BASE),
50 .length = PICOXCELL_PERIPH_LENGTH,
51 .type = MT_DEVICE,
52 };
53
picoxcell_map_io(void)54 static void __init picoxcell_map_io(void)
55 {
56 iotable_init(&io_map, 1);
57 }
58
picoxcell_init_machine(void)59 static void __init picoxcell_init_machine(void)
60 {
61 of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
62 picoxcell_setup_restart();
63 }
64
65 static const char *picoxcell_dt_match[] = {
66 "picochip,pc3x2",
67 "picochip,pc3x3",
68 NULL
69 };
70
71 static const struct of_device_id vic_of_match[] __initconst = {
72 { .compatible = "arm,pl192-vic", .data = vic_of_init, },
73 { /* Sentinel */ }
74 };
75
picoxcell_init_irq(void)76 static void __init picoxcell_init_irq(void)
77 {
78 of_irq_init(vic_of_match);
79 }
80
picoxcell_wdt_restart(char mode,const char * cmd)81 static void picoxcell_wdt_restart(char mode, const char *cmd)
82 {
83 /*
84 * Configure the watchdog to reset with the shortest possible timeout
85 * and give it chance to do the reset.
86 */
87 if (wdt_regs) {
88 writel_relaxed(WDT_CTRL_REG_EN_MASK, wdt_regs + WDT_CTRL_REG_OFFS);
89 writel_relaxed(0, wdt_regs + WDT_TIMEOUT_REG_OFFS);
90 /* No sleeping, possibly atomic. */
91 mdelay(500);
92 }
93 }
94
95 DT_MACHINE_START(PICOXCELL, "Picochip picoXcell")
96 .map_io = picoxcell_map_io,
97 .nr_irqs = NR_IRQS_LEGACY,
98 .init_irq = picoxcell_init_irq,
99 .handle_irq = vic_handle_irq,
100 .timer = &picoxcell_timer,
101 .init_machine = picoxcell_init_machine,
102 .dt_compat = picoxcell_dt_match,
103 .restart = picoxcell_wdt_restart,
104 MACHINE_END
105