From 75f10b465af9efd59906e9079ed9cbda7e0f7a43 Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Thu, 22 May 2008 16:20:18 +0100 Subject: [ARM] 5047/2: Support resetting by asserting GPIO pin This adds support for resetting via assertion of GPIO pin. This e.g. is used on Sharp Zaurus SL-6000. Signed-off-by: Dmitry Baryshkov Acked-by: Eric Miao Signed-off-by: Russell King --- arch/arm/mach-pxa/Makefile | 2 +- arch/arm/mach-pxa/reset.c | 95 +++++++++++++++++++++++++++++++++++++ include/asm-arm/arch-pxa/hardware.h | 5 ++ include/asm-arm/arch-pxa/system.h | 17 +------ 4 files changed, 102 insertions(+), 17 deletions(-) create mode 100644 arch/arm/mach-pxa/reset.c diff --git a/arch/arm/mach-pxa/Makefile b/arch/arm/mach-pxa/Makefile index 0e6d05bb81aa..c9e66fbe622e 100644 --- a/arch/arm/mach-pxa/Makefile +++ b/arch/arm/mach-pxa/Makefile @@ -4,7 +4,7 @@ # Common support (must be linked before board specific support) obj-y += clock.o devices.o generic.o irq.o dma.o \ - time.o gpio.o + time.o gpio.o reset.o obj-$(CONFIG_PM) += pm.o sleep.o standby.o obj-$(CONFIG_CPU_FREQ) += cpu-pxa.o diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c new file mode 100644 index 000000000000..551f313c94df --- /dev/null +++ b/arch/arm/mach-pxa/reset.c @@ -0,0 +1,95 @@ +/* + * 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 +#include +#include +#include +#include +#include + +#include + +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; + } +} + diff --git a/include/asm-arm/arch-pxa/hardware.h b/include/asm-arm/arch-pxa/hardware.h index e25558faa5a4..5547ec797ad0 100644 --- a/include/asm-arm/arch-pxa/hardware.h +++ b/include/asm-arm/arch-pxa/hardware.h @@ -205,6 +205,11 @@ static inline void __deprecated pxa_set_cken(int clock, int enable) */ extern unsigned int get_memclk_frequency_10khz(void); +/* + * register GPIO as reset generator + */ +extern int init_gpio_reset(int gpio); + #endif #if defined(CONFIG_MACH_ARMCORE) && defined(CONFIG_PCI) diff --git a/include/asm-arm/arch-pxa/system.h b/include/asm-arm/arch-pxa/system.h index 9aa6c2e939e8..14894ae3fa67 100644 --- a/include/asm-arm/arch-pxa/system.h +++ b/include/asm-arm/arch-pxa/system.h @@ -20,19 +20,4 @@ static inline void arch_idle(void) } -static inline void arch_reset(char mode) -{ - if (cpu_is_pxa2xx()) - RCSR = RCSR_HWR | RCSR_WDR | RCSR_SMR | RCSR_GPR; - - if (mode == 's') { - /* Jump into ROM at address 0 */ - cpu_reset(0); - } else { - /* Initialize the watchdog and let it fire */ - OWER = OWER_WME; - OSSR = OSSR_M3; - OSMR3 = OSCR + 368640; /* ... in 100 ms */ - } -} - +void arch_reset(char mode); -- cgit v1.2.2