summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorPaul Walmsley <paul@pwsan.com>2012-10-21 01:01:13 -0600
committerPaul Walmsley <paul@pwsan.com>2012-10-21 01:01:13 -0600
commit2bb2a5d30abb0dc99d074877bfad2056142c730b (patch)
tree6da1f32009cec6777baa0a474f7c2579cc57a6bc
parentb5c5353d417580f7a6ac21a0954f1c500a5cc4f5 (diff)
downloadlinux-2bb2a5d30abb0dc99d074877bfad2056142c730b.tar.gz
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>
-rw-r--r--arch/arm/mach-omap2/prm-regbits-24xx.h4
-rw-r--r--arch/arm/mach-omap2/prm-regbits-34xx.h10
-rw-r--r--arch/arm/mach-omap2/prm.h44
-rw-r--r--arch/arm/mach-omap2/prm2xxx.c68
-rw-r--r--arch/arm/mach-omap2/prm2xxx.h4
-rw-r--r--arch/arm/mach-omap2/prm2xxx_3xxx.h2
-rw-r--r--arch/arm/mach-omap2/prm3xxx.c65
-rw-r--r--arch/arm/mach-omap2/prm3xxx.h2
-rw-r--r--arch/arm/mach-omap2/prm44xx.c83
-rw-r--r--arch/arm/mach-omap2/prm44xx.h2
-rw-r--r--arch/arm/mach-omap2/prm_common.c26
11 files changed, 306 insertions, 4 deletions
diff --git a/arch/arm/mach-omap2/prm-regbits-24xx.h b/arch/arm/mach-omap2/prm-regbits-24xx.h
index bd70a5a04291..638da6dd41c3 100644
--- a/arch/arm/mach-omap2/prm-regbits-24xx.h
+++ b/arch/arm/mach-omap2/prm-regbits-24xx.h
@@ -209,9 +209,13 @@
/* RM_RSTST_WKUP specific bits */
/* 2430 calls EXTWMPU_RST "EXTWARM_RST" and GLOBALWMPU_RST "GLOBALWARM_RST" */
+#define OMAP24XX_EXTWMPU_RST_SHIFT 6
#define OMAP24XX_EXTWMPU_RST_MASK (1 << 6)
+#define OMAP24XX_SECU_WD_RST_SHIFT 5
#define OMAP24XX_SECU_WD_RST_MASK (1 << 5)
+#define OMAP24XX_MPU_WD_RST_SHIFT 4
#define OMAP24XX_MPU_WD_RST_MASK (1 << 4)
+#define OMAP24XX_SECU_VIOL_RST_SHIFT 3
#define OMAP24XX_SECU_VIOL_RST_MASK (1 << 3)
/* PM_WKEN_WKUP specific bits */
diff --git a/arch/arm/mach-omap2/prm-regbits-34xx.h b/arch/arm/mach-omap2/prm-regbits-34xx.h
index 073d4db8aa5c..838b594d4e13 100644
--- a/arch/arm/mach-omap2/prm-regbits-34xx.h
+++ b/arch/arm/mach-omap2/prm-regbits-34xx.h
@@ -509,15 +509,25 @@
#define OMAP3430_RSTTIME1_MASK (0xff << 0)
/* PRM_RSTST */
+#define OMAP3430_ICECRUSHER_RST_SHIFT 10
#define OMAP3430_ICECRUSHER_RST_MASK (1 << 10)
+#define OMAP3430_ICEPICK_RST_SHIFT 9
#define OMAP3430_ICEPICK_RST_MASK (1 << 9)
+#define OMAP3430_VDD2_VOLTAGE_MANAGER_RST_SHIFT 8
#define OMAP3430_VDD2_VOLTAGE_MANAGER_RST_MASK (1 << 8)
+#define OMAP3430_VDD1_VOLTAGE_MANAGER_RST_SHIFT 7
#define OMAP3430_VDD1_VOLTAGE_MANAGER_RST_MASK (1 << 7)
+#define OMAP3430_EXTERNAL_WARM_RST_SHIFT 6
#define OMAP3430_EXTERNAL_WARM_RST_MASK (1 << 6)
+#define OMAP3430_SECURE_WD_RST_SHIFT 5
#define OMAP3430_SECURE_WD_RST_MASK (1 << 5)
+#define OMAP3430_MPU_WD_RST_SHIFT 4
#define OMAP3430_MPU_WD_RST_MASK (1 << 4)
+#define OMAP3430_SECURITY_VIOL_RST_SHIFT 3
#define OMAP3430_SECURITY_VIOL_RST_MASK (1 << 3)
+#define OMAP3430_GLOBAL_SW_RST_SHIFT 1
#define OMAP3430_GLOBAL_SW_RST_MASK (1 << 1)
+#define OMAP3430_GLOBAL_COLD_RST_SHIFT 0
#define OMAP3430_GLOBAL_COLD_RST_MASK (1 << 0)
/* PRM_VOLTCTRL */
diff --git a/arch/arm/mach-omap2/prm.h b/arch/arm/mach-omap2/prm.h
index 3e51c1d15757..c30ab5de8d1d 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_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_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 {};
+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
diff --git a/arch/arm/mach-omap2/prm2xxx.c b/arch/arm/mach-omap2/prm2xxx.c
index 9cdb4e5e3d80..e2860f9c111d 100644
--- a/arch/arm/mach-omap2/prm2xxx.c
+++ b/arch/arm/mach-omap2/prm2xxx.c
@@ -29,6 +29,46 @@
#include "cm2xxx_3xxx.h"
#include "prm-regbits-24xx.h"
+/*
+ * omap2xxx_prm_reset_src_map - map from bits in the PRM_RSTST_WKUP
+ * hardware register (which are specific to the OMAP2xxx SoCs) to
+ * reset source ID bit shifts (which is an OMAP SoC-independent
+ * enumeration)
+ */
+static struct prm_reset_src_map omap2xxx_prm_reset_src_map[] = {
+ { OMAP_GLOBALCOLD_RST_SHIFT, OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT },
+ { OMAP_GLOBALWARM_RST_SHIFT, OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT },
+ { OMAP24XX_SECU_VIOL_RST_SHIFT, OMAP_SECU_VIOL_RST_SRC_ID_SHIFT },
+ { OMAP24XX_MPU_WD_RST_SHIFT, OMAP_MPU_WD_RST_SRC_ID_SHIFT },
+ { OMAP24XX_SECU_WD_RST_SHIFT, OMAP_SECU_WD_RST_SRC_ID_SHIFT },
+ { OMAP24XX_EXTWMPU_RST_SHIFT, OMAP_EXTWARM_RST_SRC_ID_SHIFT },
+ { -1, -1 },
+};
+
+/**
+ * omap2xxx_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 omap2xxx_prm_read_reset_sources(void)
+{
+ struct prm_reset_src_map *p;
+ u32 r = 0;
+ u32 v;
+
+ v = omap2_prm_read_mod_reg(WKUP_MOD, OMAP2_RM_RSTST);
+
+ p = omap2xxx_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;
+}
+
int omap2xxx_clkdm_sleep(struct clockdomain *clkdm)
{
omap2_prm_set_mod_reg_bits(OMAP24XX_FORCESTATE_MASK,
@@ -56,3 +96,31 @@ struct pwrdm_ops omap2_pwrdm_operations = {
.pwrdm_read_mem_retst = omap2_pwrdm_read_mem_retst,
.pwrdm_wait_transition = omap2_pwrdm_wait_transition,
};
+
+/*
+ *
+ */
+
+static struct prm_ll_data omap2xxx_prm_ll_data = {
+ .read_reset_sources = &omap2xxx_prm_read_reset_sources,
+};
+
+static int __init omap2xxx_prm_init(void)
+{
+ if (!cpu_is_omap24xx())
+ return 0;
+
+ return prm_register(&omap2xxx_prm_ll_data);
+}
+subsys_initcall(omap2xxx_prm_init);
+
+static void __exit omap2xxx_prm_exit(void)
+{
+ if (!cpu_is_omap24xx())
+ return;
+
+ /* Should never happen */
+ WARN(prm_unregister(&omap2xxx_prm_ll_data),
+ "%s: prm_ll_data function pointer mismatch\n", __func__);
+}
+__exitcall(omap2xxx_prm_exit);
diff --git a/arch/arm/mach-omap2/prm2xxx.h b/arch/arm/mach-omap2/prm2xxx.h
index 6d76716a1ea5..1d97112524f1 100644
--- a/arch/arm/mach-omap2/prm2xxx.h
+++ b/arch/arm/mach-omap2/prm2xxx.h
@@ -123,6 +123,10 @@
/* Function prototypes */
extern int omap2xxx_clkdm_sleep(struct clockdomain *clkdm);
extern int omap2xxx_clkdm_wakeup(struct clockdomain *clkdm);
+
+extern int __init prm2xxx_init(void);
+extern int __exit prm2xxx_exit(void);
+
#endif
#endif
diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.h b/arch/arm/mach-omap2/prm2xxx_3xxx.h
index 22a405a1543b..3330b1bf789d 100644
--- a/arch/arm/mach-omap2/prm2xxx_3xxx.h
+++ b/arch/arm/mach-omap2/prm2xxx_3xxx.h
@@ -211,7 +211,9 @@ extern int omap2_clkdm_clear_all_wkdeps(struct clockdomain *clkdm);
*
* 3430: RM_RSTST_CORE, RM_RSTST_EMU
*/
+#define OMAP_GLOBALWARM_RST_SHIFT 1
#define OMAP_GLOBALWARM_RST_MASK (1 << 1)
+#define OMAP_GLOBALCOLD_RST_SHIFT 0
#define OMAP_GLOBALCOLD_RST_MASK (1 << 0)
/*
diff --git a/arch/arm/mach-omap2/prm3xxx.c b/arch/arm/mach-omap2/prm3xxx.c
index e276ff270ac5..1fea656b2ca8 100644
--- a/arch/arm/mach-omap2/prm3xxx.c
+++ b/arch/arm/mach-omap2/prm3xxx.c
@@ -47,6 +47,27 @@ static struct omap_prcm_irq_setup omap3_prcm_irq_setup = {
.restore_irqen = &omap3xxx_prm_restore_irqen,
};
+/*
+ * omap3_prm_reset_src_map - map from bits in the PRM_RSTST hardware
+ * register (which are specific to OMAP3xxx SoCs) to reset source ID
+ * bit shifts (which is an OMAP SoC-independent enumeration)
+ */
+static struct prm_reset_src_map omap3xxx_prm_reset_src_map[] = {
+ { OMAP3430_GLOBAL_COLD_RST_SHIFT, OMAP_GLOBAL_COLD_RST_SRC_ID_SHIFT },
+ { OMAP3430_GLOBAL_SW_RST_SHIFT, OMAP_GLOBAL_WARM_RST_SRC_ID_SHIFT },
+ { OMAP3430_SECURITY_VIOL_RST_SHIFT, OMAP_SECU_VIOL_RST_SRC_ID_SHIFT },
+ { OMAP3430_MPU_WD_RST_SHIFT, OMAP_MPU_WD_RST_SRC_ID_SHIFT },
+ { OMAP3430_SECURE_WD_RST_SHIFT, OMAP_MPU_WD_RST_SRC_ID_SHIFT },
+ { OMAP3430_EXTERNAL_WARM_RST_SHIFT, OMAP_EXTWARM_RST_SRC_ID_SHIFT },
+ { OMAP3430_VDD1_VOLTAGE_MANAGER_RST_SHIFT,
+ OMAP_VDD_MPU_VM_RST_SRC_ID_SHIFT },
+ { OMAP3430_VDD2_VOLTAGE_MANAGER_RST_SHIFT,
+ OMAP_VDD_CORE_VM_RST_SRC_ID_SHIFT },
+ { OMAP3430_ICEPICK_RST_SHIFT, OMAP_ICEPICK_RST_SRC_ID_SHIFT },
+ { OMAP3430_ICECRUSHER_RST_SHIFT, OMAP_ICECRUSHER_RST_SRC_ID_SHIFT },
+ { -1, -1 },
+};
+
/* PRM VP */
/*
@@ -217,6 +238,30 @@ static void __init omap3xxx_prm_enable_io_wakeup(void)
PM_WKEN);
}
+/**
+ * omap3xxx_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 omap3xxx_prm_read_reset_sources(void)
+{
+ struct prm_reset_src_map *p;
+ u32 r = 0;
+ u32 v;
+
+ v = omap2_prm_read_mod_reg(WKUP_MOD, OMAP2_RM_RSTST);
+
+ p = omap3xxx_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 */
/* Applicable only for OMAP3. Not supported on OMAP2 */
@@ -320,6 +365,10 @@ struct pwrdm_ops omap3_pwrdm_operations = {
*
*/
+static struct prm_ll_data omap3xxx_prm_ll_data = {
+ .read_reset_sources = &omap3xxx_prm_read_reset_sources,
+};
+
static int __init omap3xxx_prm_init(void)
{
int ret;
@@ -327,12 +376,28 @@ static int __init omap3xxx_prm_init(void)
if (!cpu_is_omap34xx())
return 0;
+ ret = prm_register(&omap3xxx_prm_ll_data);
+ if (ret)
+ return ret;
+
omap3xxx_prm_enable_io_wakeup();
ret = omap_prcm_register_chain_handler(&omap3_prcm_irq_setup);
if (!ret)
irq_set_status_flags(omap_prcm_event_to_irq("io"),
IRQ_NOAUTOEN);
+
return ret;
}
subsys_initcall(omap3xxx_prm_init);
+
+static void __exit omap3xxx_prm_exit(void)
+{
+ if (!cpu_is_omap34xx())
+ return;
+
+ /* Should never happen */
+ WARN(prm_unregister(&omap3xxx_prm_ll_data),
+ "%s: prm_ll_data function pointer mismatch\n", __func__);
+}
+__exitcall(omap3xxx_prm_exit);
diff --git a/arch/arm/mach-omap2/prm3xxx.h b/arch/arm/mach-omap2/prm3xxx.h
index 6821e8321610..a3c28a875410 100644
--- a/arch/arm/mach-omap2/prm3xxx.h
+++ b/arch/arm/mach-omap2/prm3xxx.h
@@ -152,6 +152,8 @@ extern void omap3xxx_prm_ocp_barrier(void);
extern void omap3xxx_prm_save_and_clear_irqen(u32 *saved_mask);
extern void omap3xxx_prm_restore_irqen(u32 *saved_mask);
+extern u32 omap3xxx_prm_get_reset_sources(void);
+
#endif /* __ASSEMBLER */
diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c
index 48d91930796d..a799e9552fbf 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
* BenoƮt 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 @@ static struct omap_prcm_irq_setup omap4_prcm_irq_setup = {
.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 @@ static void __init omap44xx_prm_enable_io_wakeup(void)
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 @@ struct pwrdm_ops omap4_pwrdm_operations = {
.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);
diff --git a/arch/arm/mach-omap2/prm44xx.h b/arch/arm/mach-omap2/prm44xx.h
index ee72ae6bd8c9..c8e1accdc90e 100644
--- a/arch/arm/mach-omap2/prm44xx.h
+++ b/arch/arm/mach-omap2/prm44xx.h
@@ -771,6 +771,8 @@ extern void omap44xx_prm_ocp_barrier(void);
extern void omap44xx_prm_save_and_clear_irqen(u32 *saved_mask);
extern void omap44xx_prm_restore_irqen(u32 *saved_mask);
+extern u32 omap44xx_prm_get_reset_sources(void);
+
# endif
#endif
diff --git a/arch/arm/mach-omap2/prm_common.c b/arch/arm/mach-omap2/prm_common.c
index 8670a3c4bc5e..e200e4fb47dc 100644
--- a/arch/arm/mach-omap2/prm_common.c
+++ b/arch/arm/mach-omap2/prm_common.c
@@ -28,6 +28,8 @@
#include <plat/prcm.h>
#include "prm2xxx_3xxx.h"
+#include "prm2xxx.h"
+#include "prm3xxx.h"
#include "prm44xx.h"
/*
@@ -327,6 +329,30 @@ err:
}
/**
+ * prm_read_reset_sources - return the sources of the SoC's last reset
+ *
+ * Return a u32 bitmask representing the reset sources that caused the
+ * SoC to reset. The low-level per-SoC functions called by this
+ * function remap the SoC-specific reset source bits into an
+ * OMAP-common set of reset source bits, defined in
+ * arch/arm/mach-omap2/prm.h. Returns the standardized reset source
+ * u32 bitmask from the hardware upon success, or returns (1 <<
+ * OMAP_UNKNOWN_RST_SRC_ID_SHIFT) if no low-level read_reset_sources()
+ * function was registered.
+ */
+u32 prm_read_reset_sources(void)
+{
+ u32 ret = 1 << OMAP_UNKNOWN_RST_SRC_ID_SHIFT;
+
+ if (prm_ll_data->read_reset_sources)
+ ret = prm_ll_data->read_reset_sources();
+ else
+ WARN_ONCE(1, "prm: %s: no mapping function defined for reset sources\n", __func__);
+
+ return ret;
+}
+
+/**
* prm_register - register per-SoC low-level data with the PRM
* @pld: low-level per-SoC OMAP PRM data & function pointers to register
*