As per OMAP3630 TRM Section 3.5.7.2.2, the right sequence for enabling IO Daisy
chain is "The I/O wake-up scheme is enabled by triggering the I/O daisy chain
control (Wu clock) by programming a dedicated register
(PRCM.PM_WKEN_WKUP[16] EN_IO_CHAIN) in the PRCM module.Software must wait for
the I/O daisy chain to complete before it transitions the PER domain to a
nonfunctional state. This is done by polling a dedicated status bit in the PRCM
module (PRCM.PM_WKST_WKUP[16] ST_IO_CHAIN). This status bit must be cleared by
software when the bit is read to 1".
The original code was polling on a wrong register which is fixed in this patch.
Also omap3_enable_io_chain is made non static as it's going to be used in
subsequent patches.
Signed-off-by: Vishwanath BS <vishwanath.bs@xxxxxx>
---
arch/arm/mach-omap2/pm.h | 1 +
arch/arm/mach-omap2/pm34xx.c | 6 +++---
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 4e166ad..9a36a7c 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -21,6 +21,7 @@ extern void omap_sram_idle(void);
extern int omap3_can_sleep(void);
extern int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 state);
extern int omap3_idle_init(void);
+extern void omap3_enable_io_chain(void);
#if defined(CONFIG_PM_OPP)
extern int omap3_opp_init(void);
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 7255d9b..61f1a5b 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -95,7 +95,7 @@ static inline void omap3_per_restore_context(void)
omap_gpio_restore_context();
}
-static void omap3_enable_io_chain(void)
+void omap3_enable_io_chain(void)
{
int timeout = 0;
@@ -105,7 +105,7 @@ static void omap3_enable_io_chain(void)
/* Do a readback to assure write has been done */
omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
- while (!(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN) &
+ while (!(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST) &
OMAP3430_ST_IO_CHAIN_MASK)) {
timeout++;
if (timeout > 1000) {
@@ -114,7 +114,7 @@ static void omap3_enable_io_chain(void)
return;
}
omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK,
- WKUP_MOD, PM_WKEN);
+ WKUP_MOD, PM_WKST);
}
}
}
--
1.7.0.4
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