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 "hardware.h" 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 26 void 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 */ 46 u32 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