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/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index 48d91930..a799e95 100644
--- a/arch/arm/mach-omap2/prm44xx.c
+++ b/arch/arm/mach-omap2/prm44xx.c
@@ -1,7 +1,7 @@
/*
* OMAP4 PRM module functions
*
- * Copyright (C) 2011 Texas Instruments, Inc.
+ * Copyright (C) 2011-2012 Texas Instruments, Inc.
* Copyright (C) 2010 Nokia Corporation
* Benoît Cousson
* Paul Walmsley
@@ -30,6 +30,8 @@
#include "prminst44xx.h"
#include "powerdomain.h"
+/* Static data */
+
static const struct omap_prcm_irq omap4_prcm_irqs[] = {
OMAP_PRCM_IRQ("wkup", 0, 0),
OMAP_PRCM_IRQ("io", 9, 1),
@@ -48,6 +50,33 @@
.restore_irqen = &omap44xx_prm_restore_irqen,
};
+/*
+ * omap44xx_prm_reset_src_map - map from bits in the PRM_RSTST
+ * hardware register (which are specific to OMAP44xx SoCs) to reset
+ * source ID bit shifts (which is an OMAP SoC-independent
+ * enumeration)
+ */
+static struct prm_reset_src_map omap44xx_prm_reset_src_map[] = {
+ { OMAP4430_RST_GLOBAL_WARM_SW_SHIFT,
+ OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT },
+ { OMAP4430_RST_GLOBAL_COLD_SW_SHIFT,
+ OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT },
+ { OMAP4430_MPU_SECURITY_VIOL_RST_SHIFT,
+ OMAP_SECU_VIOL_RST_SRC_ID_SHIFT },
+ { OMAP4430_MPU_WDT_RST_SHIFT, OMAP_MPU_WD_RST_SRC_ID_SHIFT },
+ { OMAP4430_SECURE_WDT_RST_SHIFT, OMAP_SECU_WD_RST_SRC_ID_SHIFT },
+ { OMAP4430_EXTERNAL_WARM_RST_SHIFT, OMAP_EXTWARM_RST_SRC_ID_SHIFT },
+ { OMAP4430_VDD_MPU_VOLT_MGR_RST_SHIFT,
+ OMAP_VDD_MPU_VM_RST_SRC_ID_SHIFT },
+ { OMAP4430_VDD_IVA_VOLT_MGR_RST_SHIFT,
+ OMAP_VDD_IVA_VM_RST_SRC_ID_SHIFT },
+ { OMAP4430_VDD_CORE_VOLT_MGR_RST_SHIFT,
+ OMAP_VDD_CORE_VM_RST_SRC_ID_SHIFT },
+ { OMAP4430_ICEPICK_RST_SHIFT, OMAP_ICEPICK_RST_SRC_ID_SHIFT },
+ { OMAP4430_C2C_RST_SHIFT, OMAP_C2C_RST_SRC_ID_SHIFT },
+ { -1, -1 },
+};
+
/* PRM low-level functions */
/* Read a register in a CM/PRM instance in the PRM module */
@@ -293,6 +322,31 @@
OMAP4_PRM_IO_PMCTRL_OFFSET);
}
+/**
+ * omap44xx_prm_read_reset_sources - return the last SoC reset source
+ *
+ * Return a u32 representing the last reset sources of the SoC. The
+ * returned reset source bits are standardized across OMAP SoCs.
+ */
+static u32 omap44xx_prm_read_reset_sources(void)
+{
+ struct prm_reset_src_map *p;
+ u32 r = 0;
+ u32 v;
+
+ v = omap4_prm_read_inst_reg(OMAP4430_PRM_OCP_SOCKET_INST,
+ OMAP4_RM_RSTST);
+
+ p = omap44xx_prm_reset_src_map;
+ while (p->reg_shift >= 0 && p->std_shift >= 0) {
+ if (v & (1 << p->reg_shift))
+ r |= 1 << p->std_shift;
+ p++;
+ }
+
+ return r;
+}
+
/* Powerdomain low-level functions */
static int omap4_pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
@@ -555,14 +609,37 @@
.pwrdm_wait_transition = omap4_pwrdm_wait_transition,
};
+/*
+ * XXX document
+ */
+static struct prm_ll_data omap44xx_prm_ll_data = {
+ .read_reset_sources = &omap44xx_prm_read_reset_sources,
+};
-static int __init omap4xxx_prm_init(void)
+static int __init omap44xx_prm_init(void)
{
+ int ret;
+
if (!cpu_is_omap44xx())
return 0;
+ ret = prm_register(&omap44xx_prm_ll_data);
+ if (ret)
+ return ret;
+
omap44xx_prm_enable_io_wakeup();
return omap_prcm_register_chain_handler(&omap4_prcm_irq_setup);
}
-subsys_initcall(omap4xxx_prm_init);
+subsys_initcall(omap44xx_prm_init);
+
+static void __exit omap44xx_prm_exit(void)
+{
+ if (!cpu_is_omap44xx())
+ return;
+
+ /* Should never happen */
+ WARN(prm_unregister(&omap44xx_prm_ll_data),
+ "%s: prm_ll_data function pointer mismatch\n", __func__);
+}
+__exitcall(omap44xx_prm_exit);