linux/arch/arm/mach-omap1/reset.c
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   1/*
   2 * OMAP1 reset support
   3 */
   4#include <linux/kernel.h>
   5#include <linux/io.h>
   6#include <linux/reboot.h>
   7
   8#include <mach/hardware.h>
   9
  10#include "iomap.h"
  11#include "common.h"
  12
  13/* ARM_SYSST bit shifts related to SoC reset sources */
  14#define ARM_SYSST_POR_SHIFT                             5
  15#define ARM_SYSST_EXT_RST_SHIFT                         4
  16#define ARM_SYSST_ARM_WDRST_SHIFT                       2
  17#define ARM_SYSST_GLOB_SWRST_SHIFT                      1
  18
  19/* Standardized reset source bits (across all OMAP SoCs) */
  20#define OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT               0
  21#define OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT               1
  22#define OMAP_MPU_WD_RST_SRC_ID_SHIFT                    3
  23#define OMAP_EXTWARM_RST_SRC_ID_SHIFT                   5
  24
  25
  26void omap1_restart(enum reboot_mode mode, const char *cmd)
  27{
  28        /*
  29         * Workaround for 5912/1611b bug mentioned in sprz209d.pdf p. 28
  30         * "Global Software Reset Affects Traffic Controller Frequency".
  31         */
  32        if (cpu_is_omap5912()) {
  33                omap_writew(omap_readw(DPLL_CTL) & ~(1 << 4), DPLL_CTL);
  34                omap_writew(0x8, ARM_RSTCT1);
  35        }
  36
  37        omap_writew(1, ARM_RSTCT1);
  38}
  39
  40/**
  41 * omap1_get_reset_sources - return the source of the SoC's last reset
  42 *
  43 * Returns bits that represent the last reset source for the SoC.  The
  44 * format is standardized across OMAPs for use by the OMAP watchdog.
  45 */
  46u32 omap1_get_reset_sources(void)
  47{
  48        u32 ret = 0;
  49        u16 rs;
  50
  51        rs = __raw_readw(OMAP1_IO_ADDRESS(ARM_SYSST));
  52
  53        if (rs & (1 << ARM_SYSST_POR_SHIFT))
  54                ret |= 1 << OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT;
  55        if (rs & (1 << ARM_SYSST_EXT_RST_SHIFT))
  56                ret |= 1 << OMAP_EXTWARM_RST_SRC_ID_SHIFT;
  57        if (rs & (1 << ARM_SYSST_ARM_WDRST_SHIFT))
  58                ret |= 1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT;
  59        if (rs & (1 << ARM_SYSST_GLOB_SWRST_SHIFT))
  60                ret |= 1 << OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT;
  61
  62        return ret;
  63}
  64