/* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/delay.h> #include <linux/gpio.h> #include <asm/io.h> #include <asm/proc-fns.h> #include <mach/pxa-regs.h> #include <mach/reset.h> unsigned int reset_status; EXPORT_SYMBOL(reset_status); static void do_hw_reset(void); static int reset_gpio = -1; int init_gpio_reset(int gpio) { int rc; rc = gpio_request(gpio, "reset generator"); if (rc) { printk(KERN_ERR "Can't request reset_gpio\n"); goto out; } rc = gpio_direction_input(gpio); if (rc) { printk(KERN_ERR "Can't configure reset_gpio for input\n"); gpio_free(gpio); goto out; } out: if (!rc) reset_gpio = gpio; return rc; } /* * Trigger GPIO reset. * This covers various types of logic connecting gpio pin * to RESET pins (nRESET or GPIO_RESET): */ static void do_gpio_reset(void) { BUG_ON(reset_gpio == -1); /* drive it low */ gpio_direction_output(reset_gpio, 0); mdelay(2); /* rising edge or drive high */ gpio_set_value(reset_gpio, 1); mdelay(2); /* falling edge */ gpio_set_value(reset_gpio, 0); /* give it some time */ mdelay(10); WARN_ON(1); /* fallback */ do_hw_reset(); } static void do_hw_reset(void) { /* Initialize the watchdog and let it fire */ OWER = OWER_WME; OSSR = OSSR_M3; OSMR3 = OSCR + 368640; /* ... in 100 ms */ } void arch_reset(char mode) { clear_reset_status(RESET_STATUS_ALL); switch (mode) { case 's': /* Jump into ROM at address 0 */ cpu_reset(0); break; case 'h': do_hw_reset(); break; case 'g': do_gpio_reset(); break; } }