/* * 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 <linux/io.h> #include <asm/proc-fns.h> #include <asm/system_misc.h> #include <mach/regs-ost.h> #include <mach/reset.h> #include <mach/smemc.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 output, int level) { int rc; rc = gpio_request(gpio, "reset generator"); if (rc) { printk(KERN_ERR "Can't request reset_gpio\n"); goto out; } if (output) rc = gpio_direction_output(gpio, level); else rc = gpio_direction_input(gpio); if (rc) { printk(KERN_ERR "Can't configure reset_gpio\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 */ writel_relaxed(OWER_WME, OWER); writel_relaxed(OSSR_M3, OSSR); /* ... in 100 ms */ writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3); /* * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71) * we put SDRAM into self-refresh to prevent that */ while (1) writel_relaxed(MDREFR_SLFRSH, MDREFR); } void pxa_restart(enum reboot_mode mode, const char *cmd) { local_irq_disable(); local_fiq_disable(); clear_reset_status(RESET_STATUS_ALL); switch (mode) { case REBOOT_SOFT: /* Jump into ROM at address 0 */ soft_restart(0); break; case REBOOT_GPIO: do_gpio_reset(); break; case REBOOT_HARD: default: do_hw_reset(); break; } }