diff options
Diffstat (limited to 'arch/arm/mach-pxa/reset.c')
-rw-r--r-- | arch/arm/mach-pxa/reset.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c new file mode 100644 index 000000000..263b15249 --- /dev/null +++ b/arch/arm/mach-pxa/reset.c @@ -0,0 +1,113 @@ +/* + * 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; + } +} |