linuxdebug/arch/arm/mach-omap1/reset.c

64 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* OMAP1 reset support
*/
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/reboot.h>
#include "hardware.h"
#include "iomap.h"
#include "common.h"
/* ARM_SYSST bit shifts related to SoC reset sources */
#define ARM_SYSST_POR_SHIFT 5
#define ARM_SYSST_EXT_RST_SHIFT 4
#define ARM_SYSST_ARM_WDRST_SHIFT 2
#define ARM_SYSST_GLOB_SWRST_SHIFT 1
/* Standardized reset source bits (across all OMAP SoCs) */
#define OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT 0
#define OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT 1
#define OMAP_MPU_WD_RST_SRC_ID_SHIFT 3
#define OMAP_EXTWARM_RST_SRC_ID_SHIFT 5
void omap1_restart(enum reboot_mode mode, const char *cmd)
{
/*
* Workaround for 5912/1611b bug mentioned in sprz209d.pdf p. 28
* "Global Software Reset Affects Traffic Controller Frequency".
*/
if (cpu_is_omap5912()) {
omap_writew(omap_readw(DPLL_CTL) & ~(1 << 4), DPLL_CTL);
omap_writew(0x8, ARM_RSTCT1);
}
omap_writew(1, ARM_RSTCT1);
}
/**
* omap1_get_reset_sources - return the source of the SoC's last reset
*
* Returns bits that represent the last reset source for the SoC. The
* format is standardized across OMAPs for use by the OMAP watchdog.
*/
u32 omap1_get_reset_sources(void)
{
u32 ret = 0;
u16 rs;
rs = __raw_readw(OMAP1_IO_ADDRESS(ARM_SYSST));
if (rs & (1 << ARM_SYSST_POR_SHIFT))
ret |= 1 << OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT;
if (rs & (1 << ARM_SYSST_EXT_RST_SHIFT))
ret |= 1 << OMAP_EXTWARM_RST_SRC_ID_SHIFT;
if (rs & (1 << ARM_SYSST_ARM_WDRST_SHIFT))
ret |= 1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT;
if (rs & (1 << ARM_SYSST_GLOB_SWRST_SHIFT))
ret |= 1 << OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT;
return ret;
}