projects / mirror_ubuntu-artful-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 75f10b46 DES |
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 | ||
| 13 | #include <asm/arch/pxa-regs.h> | |
| 4d1fe075 | 14 | #include <asm/arch/pxa2xx-regs.h> |
| ab277121 | 15 | #include <asm/arch/reset.h> |
| 75f10b46 DES |
16 | |
| 17 | static void do_hw_reset(void); | |
| 18 | ||
| 19 | static int reset_gpio = -1; | |
| 20 | ||
| 21 | int init_gpio_reset(int gpio) | |
| 22 | { | |
| 23 | int rc; | |
| 24 | ||
| 25 | rc = gpio_request(gpio, "reset generator"); | |
| 26 | if (rc) { | |
| 27 | printk(KERN_ERR "Can't request reset_gpio\n"); | |
| 28 | goto out; | |
| 29 | } | |
| 30 | ||
| 31 | rc = gpio_direction_input(gpio); | |
| 32 | if (rc) { | |
| 33 | printk(KERN_ERR "Can't configure reset_gpio for input\n"); | |
| 34 | gpio_free(gpio); | |
| 35 | goto out; | |
| 36 | } | |
| 37 | ||
| 38 | out: | |
| 39 | if (!rc) | |
| 40 | reset_gpio = gpio; | |
| 41 | ||
| 42 | return rc; | |
| 43 | } | |
| 44 | ||
| 45 | /* | |
| 46 | * Trigger GPIO reset. | |
| 47 | * This covers various types of logic connecting gpio pin | |
| 48 | * to RESET pins (nRESET or GPIO_RESET): | |
| 49 | */ | |
| 50 | static void do_gpio_reset(void) | |
| 51 | { | |
| 52 | BUG_ON(reset_gpio == -1); | |
| 53 | ||
| 54 | /* drive it low */ | |
| 55 | gpio_direction_output(reset_gpio, 0); | |
| 56 | mdelay(2); | |
| 57 | /* rising edge or drive high */ | |
| 58 | gpio_set_value(reset_gpio, 1); | |
| 59 | mdelay(2); | |
| 60 | /* falling edge */ | |
| 61 | gpio_set_value(reset_gpio, 0); | |
| 62 | ||
| 63 | /* give it some time */ | |
| 64 | mdelay(10); | |
| 65 | ||
| 66 | WARN_ON(1); | |
| 67 | /* fallback */ | |
| 68 | do_hw_reset(); | |
| 69 | } | |
| 70 | ||
| 71 | static void do_hw_reset(void) | |
| 72 | { | |
| 73 | /* Initialize the watchdog and let it fire */ | |
| 74 | OWER = OWER_WME; | |
| 75 | OSSR = OSSR_M3; | |
| 76 | OSMR3 = OSCR + 368640; /* ... in 100 ms */ | |
| 77 | } | |
| 78 | ||
| 79 | void arch_reset(char mode) | |
| 80 | { | |
| 81 | if (cpu_is_pxa2xx()) | |
| 82 | RCSR = RCSR_HWR | RCSR_WDR | RCSR_SMR | RCSR_GPR; | |
| 83 | ||
| 84 | switch (mode) { | |
| 85 | case 's': | |
| 86 | /* Jump into ROM at address 0 */ | |
| 87 | cpu_reset(0); | |
| 88 | break; | |
| 89 | case 'h': | |
| 90 | do_hw_reset(); | |
| 91 | break; | |
| 92 | case 'g': | |
| 93 | do_gpio_reset(); | |
| 94 | break; | |
| 95 | } | |
| 96 | } | |
| 97 |