[PATCHv3 1/6] ARM: OMAP3 PM: correct enable/disable of daisy io chain
Tero Kristo
t-kristo at ti.com
Wed Feb 29 09:26:56 EST 2012
From: Mohan V <mohanv at ti.com>
Currently the enabling and disabling of IO Daisy chain is not
according to the TRM. The below steps are followed to enable/
disable the IO chain according to the "Sec 3.5.7.2.2
I/O Wake-Up Mechanism" in OMAP3630 Public TRM[1].
Steps to enable IO chain:
[a] Set PM_WKEN_WKUP.EN_IO bit
[b] Set the PM_WKEN_WKUP.EN_IO_CHAIN bit
[c] Poll for PM_WKST_WKUP.ST_IO_CHAIN.
[d] When ST_IO_CHAIN bit set to 1, clear PM_WKEN_WKUP.EN_IO_CHAIN
[e] Clear ST_IO_CHAIN bit.
Steps to disable IO chain:
[a] Clear PM_WKEN_WKUP.EN_IO_CHAIN bit
[b] Clear PM_WKEN_WKUP.EN_IO bit
[c] Clear PM_WKST_WKUP.ST_IO bit by writing 1 to it.
Step [e] & [c] in each case can be skipped, as these are handled
by the PRCM interrupt handler later.
[1] http://focus.ti.com/pdfs/wtbu/OMAP36xx_ES1.x_PUBLIC_TRM_vV.zip
Signed-off-by: Mohan V <mohanv at ti.com>
Signed-off-by: Vishwanath BS <vishwanath.bs at ti.com>
Signed-off-by: Tero Kristo <t-kristo at ti.com>
---
arch/arm/mach-omap2/pm34xx.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index fc69875..b0821a8 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -94,16 +94,17 @@ 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) {
pr_err("Wake up daisy chain activation failed.\n");
return;
}
- omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK,
- WKUP_MOD, PM_WKEN);
}
+ omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
+ PM_WKEN);
+
}
static void omap3_disable_io_chain(void)
--
1.7.4.1
More information about the linux-arm-kernel
mailing list