1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * OMAP1 reset support 4 */ 5 #include <linux/kernel.h> 6 #include <linux/io.h> 7 #include <linux/reboot.h> 8 9 #include <mach/hardware.h> 10 11 #include "iomap.h" 12 #include "common.h" 13 14 /* ARM_SYSST bit shifts related to SoC reset sources */ 15 #define ARM_SYSST_POR_SHIFT 5 16 #define ARM_SYSST_EXT_RST_SHIFT 4 17 #define ARM_SYSST_ARM_WDRST_SHIFT 2 18 #define ARM_SYSST_GLOB_SWRST_SHIFT 1 19 20 /* Standardized reset source bits (across all OMAP SoCs) */ 21 #define OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT 0 22 #define OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT 1 23 #define OMAP_MPU_WD_RST_SRC_ID_SHIFT 3 24 #define OMAP_EXTWARM_RST_SRC_ID_SHIFT 5 25 26 27 void omap1_restart(enum reboot_mode mode, const char *cmd) 28 { 29 /* 30 * Workaround for 5912/1611b bug mentioned in sprz209d.pdf p. 28 31 * "Global Software Reset Affects Traffic Controller Frequency". 32 */ 33 if (cpu_is_omap5912()) { 34 omap_writew(omap_readw(DPLL_CTL) & ~(1 << 4), DPLL_CTL); 35 omap_writew(0x8, ARM_RSTCT1); 36 } 37 38 omap_writew(1, ARM_RSTCT1); 39 } 40 41 /** 42 * omap1_get_reset_sources - return the source of the SoC's last reset 43 * 44 * Returns bits that represent the last reset source for the SoC. The 45 * format is standardized across OMAPs for use by the OMAP watchdog. 46 */ 47 u32 omap1_get_reset_sources(void) 48 { 49 u32 ret = 0; 50 u16 rs; 51 52 rs = __raw_readw(OMAP1_IO_ADDRESS(ARM_SYSST)); 53 54 if (rs & (1 << ARM_SYSST_POR_SHIFT)) 55 ret |= 1 << OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT; 56 if (rs & (1 << ARM_SYSST_EXT_RST_SHIFT)) 57 ret |= 1 << OMAP_EXTWARM_RST_SRC_ID_SHIFT; 58 if (rs & (1 << ARM_SYSST_ARM_WDRST_SHIFT)) 59 ret |= 1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT; 60 if (rs & (1 << ARM_SYSST_GLOB_SWRST_SHIFT)) 61 ret |= 1 << OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT; 62 63 return ret; 64 } 65