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Commit 75f10b46 authored by Dmitry Eremin-Solenikov's avatar Dmitry Eremin-Solenikov Committed by Russell King
Browse files

[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: default avatarDmitry Baryshkov <dbaryshkov@gmail.com>
Acked-by: default avatarEric Miao <eric.miao@marvell.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent b8291ad0

arch/arm/mach-pxa/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/arm/mach-pxa/reset.c

0 → 100644
+95 −0
Original line number Diff line number Diff line 
/*

 * 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>



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;

	}

}

include/asm-arm/arch-pxa/hardware.h

+5 −0
Original line number Diff line number Diff line
@@ -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)

include/asm-arm/arch-pxa/system.h

+1 −16
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@@ -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);