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