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author | Paul Walmsley <paul@pwsan.com> | 2012-10-21 07:01:13 (GMT) |
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committer | Paul Walmsley <paul@pwsan.com> | 2012-10-21 07:01:13 (GMT) |
commit | 2bb2a5d30abb0dc99d074877bfad2056142c730b (patch) | |
tree | 6da1f32009cec6777baa0a474f7c2579cc57a6bc /arch/arm/mach-omap2/prm2xxx.c | |
parent | b5c5353d417580f7a6ac21a0954f1c500a5cc4f5 (diff) | |
download | linux-2bb2a5d30abb0dc99d074877bfad2056142c730b.tar.xz |
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>
Diffstat (limited to 'arch/arm/mach-omap2/prm2xxx.c')
-rw-r--r-- | arch/arm/mach-omap2/prm2xxx.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/prm2xxx.c b/arch/arm/mach-omap2/prm2xxx.c index 9cdb4e5..e2860f9 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); |