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75f10b46 DB |
1 | /* |
2 | * This program is free software; you can redistribute it and/or modify | |
3 | * it under the terms of the GNU General Public License version 2 as | |
4 | * published by the Free Software Foundation. | |
5 | */ | |
6 | #include <linux/kernel.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/delay.h> | |
9 | #include <linux/gpio.h> | |
10 | #include <asm/io.h> | |
11 | #include <asm/proc-fns.h> | |
12 | ||
a09e64fb RK |
13 | #include <mach/pxa-regs.h> |
14 | #include <mach/pxa2xx-regs.h> | |
75f10b46 DB |
15 | |
16 | static void do_hw_reset(void); | |
17 | ||
18 | static int reset_gpio = -1; | |
19 | ||
20 | int init_gpio_reset(int gpio) | |
21 | { | |
22 | int rc; | |
23 | ||
24 | rc = gpio_request(gpio, "reset generator"); | |
25 | if (rc) { | |
26 | printk(KERN_ERR "Can't request reset_gpio\n"); | |
27 | goto out; | |
28 | } | |
29 | ||
30 | rc = gpio_direction_input(gpio); | |
31 | if (rc) { | |
32 | printk(KERN_ERR "Can't configure reset_gpio for input\n"); | |
33 | gpio_free(gpio); | |
34 | goto out; | |
35 | } | |
36 | ||
37 | out: | |
38 | if (!rc) | |
39 | reset_gpio = gpio; | |
40 | ||
41 | return rc; | |
42 | } | |
43 | ||
44 | /* | |
45 | * Trigger GPIO reset. | |
46 | * This covers various types of logic connecting gpio pin | |
47 | * to RESET pins (nRESET or GPIO_RESET): | |
48 | */ | |
49 | static void do_gpio_reset(void) | |
50 | { | |
51 | BUG_ON(reset_gpio == -1); | |
52 | ||
53 | /* drive it low */ | |
54 | gpio_direction_output(reset_gpio, 0); | |
55 | mdelay(2); | |
56 | /* rising edge or drive high */ | |
57 | gpio_set_value(reset_gpio, 1); | |
58 | mdelay(2); | |
59 | /* falling edge */ | |
60 | gpio_set_value(reset_gpio, 0); | |
61 | ||
62 | /* give it some time */ | |
63 | mdelay(10); | |
64 | ||
65 | WARN_ON(1); | |
66 | /* fallback */ | |
67 | do_hw_reset(); | |
68 | } | |
69 | ||
70 | static void do_hw_reset(void) | |
71 | { | |
72 | /* Initialize the watchdog and let it fire */ | |
73 | OWER = OWER_WME; | |
74 | OSSR = OSSR_M3; | |
75 | OSMR3 = OSCR + 368640; /* ... in 100 ms */ | |
76 | } | |
77 | ||
78 | void arch_reset(char mode) | |
79 | { | |
80 | if (cpu_is_pxa2xx()) | |
81 | RCSR = RCSR_HWR | RCSR_WDR | RCSR_SMR | RCSR_GPR; | |
82 | ||
83 | switch (mode) { | |
84 | case 's': | |
85 | /* Jump into ROM at address 0 */ | |
86 | cpu_reset(0); | |
87 | break; | |
88 | case 'h': | |
89 | do_hw_reset(); | |
90 | break; | |
91 | case 'g': | |
92 | do_gpio_reset(); | |
93 | break; | |
94 | } | |
95 | } | |
96 |