arch/arm/mach-omap1/reset.c

   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
  25 void 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  */
  45 u32 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 }