diff options
Diffstat (limited to 'arch/arm/mach-omap1/reset.c')
-rw-r--r-- | arch/arm/mach-omap1/reset.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/arm/mach-omap1/reset.c b/arch/arm/mach-omap1/reset.c new file mode 100644 index 0000000000..2eee6a6965 --- /dev/null +++ b/arch/arm/mach-omap1/reset.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * OMAP1 reset support + */ +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/reboot.h> + +#include "hardware.h" +#include "iomap.h" +#include "common.h" + +/* ARM_SYSST bit shifts related to SoC reset sources */ +#define ARM_SYSST_POR_SHIFT 5 +#define ARM_SYSST_EXT_RST_SHIFT 4 +#define ARM_SYSST_ARM_WDRST_SHIFT 2 +#define ARM_SYSST_GLOB_SWRST_SHIFT 1 + +/* Standardized reset source bits (across all OMAP SoCs) */ +#define OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT 0 +#define OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT 1 +#define OMAP_MPU_WD_RST_SRC_ID_SHIFT 3 +#define OMAP_EXTWARM_RST_SRC_ID_SHIFT 5 + + +void omap1_restart(enum reboot_mode mode, const char *cmd) +{ + /* + * Workaround for 5912/1611b bug mentioned in sprz209d.pdf p. 28 + * "Global Software Reset Affects Traffic Controller Frequency". + */ + if (cpu_is_omap5912()) { + omap_writew(omap_readw(DPLL_CTL) & ~(1 << 4), DPLL_CTL); + omap_writew(0x8, ARM_RSTCT1); + } + + omap_writew(1, ARM_RSTCT1); +} + +/** + * omap1_get_reset_sources - return the source of the SoC's last reset + * + * Returns bits that represent the last reset source for the SoC. The + * format is standardized across OMAPs for use by the OMAP watchdog. + */ +u32 omap1_get_reset_sources(void) +{ + u32 ret = 0; + u16 rs; + + rs = __raw_readw(OMAP1_IO_ADDRESS(ARM_SYSST)); + + if (rs & (1 << ARM_SYSST_POR_SHIFT)) + ret |= 1 << OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT; + if (rs & (1 << ARM_SYSST_EXT_RST_SHIFT)) + ret |= 1 << OMAP_EXTWARM_RST_SRC_ID_SHIFT; + if (rs & (1 << ARM_SYSST_ARM_WDRST_SHIFT)) + ret |= 1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT; + if (rs & (1 << ARM_SYSST_GLOB_SWRST_SHIFT)) + ret |= 1 << OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT; + + return ret; +} |