diff options
Diffstat (limited to 'arch/arm/mach-pxa/reset.c')
| -rw-r--r-- | arch/arm/mach-pxa/reset.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c new file mode 100644 index 000000000000..9d39dea57ce2 --- /dev/null +++ b/arch/arm/mach-pxa/reset.c @@ -0,0 +1,96 @@ +/* + * 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 <asm/arch/pxa-regs.h> +#include <asm/arch/pxa2xx-regs.h> + +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) +{ + if (cpu_is_pxa2xx()) + RCSR = RCSR_HWR | RCSR_WDR | RCSR_SMR | RCSR_GPR; + + 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; + } +} + |