ARM: OMAP2+: PRM: create PRM reset source API for the watchdog timer driver
The OMAP watchdog timer driver needs to determine what caused the SoC
to reset for its GETBOOTSTATUS ioctl. So, define a set of standard
reset sources across OMAP SoCs. For OMAP2xxx, 3xxx, and 4xxx SoCs,
define mappings from the SoC-specific reset source register bits to
the standardized reset source IDs. Create SoC-specific PRM functions
that read the appropriate per-SoC register and use the mapping to
return the standardized reset bits. Register the SoC-specific PRM
functions with the common PRM code via prm_register(). Create a
function in the common PRM code, prm_read_reset_sources(), that
calls the SoC-specific function, registered during boot.
This patch does not yet handle some SoCs, such as AM33xx. Those SoCs
were not handled by the code this will replace.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
diff --git a/arch/arm/mach-omap2/prm.h b/arch/arm/mach-omap2/prm.h
index 3e51c1d..c30ab5d 100644
--- a/arch/arm/mach-omap2/prm.h
+++ b/arch/arm/mach-omap2/prm.h
@@ -52,16 +52,58 @@
#define OMAP_POWERSTATE_SHIFT 0
#define OMAP_POWERSTATE_MASK (0x3 << 0)
+/*
+ * Standardized OMAP reset source bits
+ *
+ * To the extent these happen to match the hardware register bit
+ * shifts, it's purely coincidental. Used by omap-wdt.c.
+ * OMAP_UNKNOWN_RST_SRC_ID_SHIFT is a special value, used whenever
+ * there are any bits remaining in the global PRM_RSTST register that
+ * haven't been identified, or when the PRM code for the current SoC
+ * doesn't know how to interpret the register.
+ */
+#define OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT 0
+#define OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT 1
+#define OMAP_SECU_VIOL_RST_SRC_ID_SHIFT 2
+#define OMAP_MPU_WD_RST_SRC_ID_SHIFT 3
+#define OMAP_SECU_WD_RST_SRC_ID_SHIFT 4
+#define OMAP_EXTWARM_RST_SRC_ID_SHIFT 5
+#define OMAP_VDD_MPU_VM_RST_SRC_ID_SHIFT 6
+#define OMAP_VDD_IVA_VM_RST_SRC_ID_SHIFT 7
+#define OMAP_VDD_CORE_VM_RST_SRC_ID_SHIFT 8
+#define OMAP_ICEPICK_RST_SRC_ID_SHIFT 9
+#define OMAP_ICECRUSHER_RST_SRC_ID_SHIFT 10
+#define OMAP_C2C_RST_SRC_ID_SHIFT 11
+#define OMAP_UNKNOWN_RST_SRC_ID_SHIFT 12
+
#ifndef __ASSEMBLER__
/**
- * struct prm_ll_data - fn ptrs to per-SoC PRM function implementations
+ * struct prm_reset_src_map - map register bitshifts to standard bitshifts
+ * @reg_shift: bitshift in the PRM reset source register
+ * @std_shift: bitshift equivalent in the standard reset source list
+ *
+ * The fields are signed because -1 is used as a terminator.
*/
-struct prm_ll_data {};
+struct prm_reset_src_map {
+ s8 reg_shift;
+ s8 std_shift;
+};
+
+/**
+ * struct prm_ll_data - fn ptrs to per-SoC PRM function implementations
+ * @read_reset_sources: ptr to the Soc PRM-specific get_reset_source impl
+ */
+struct prm_ll_data {
+ u32 (*read_reset_sources)(void);
+};
extern int prm_register(struct prm_ll_data *pld);
extern int prm_unregister(struct prm_ll_data *pld);
+extern u32 prm_read_reset_sources(void);
+
#endif
+
#endif