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authorMohan V <mohanv@ti.com>2012-06-22 14:40:02 (GMT)
committerPaul Walmsley <paul@pwsan.com>2012-06-22 14:40:02 (GMT)
commitfe7ea0062f2f846bb68447c7b813b9230285dbeb (patch)
treeb32c0698f2ea3a4d55c986638ab34d3205baefea /arch
parent75a4433e409b2d22cbe443b623d92047b59cbb9a (diff)
downloadlinux-fsl-qoriq-fe7ea0062f2f846bb68447c7b813b9230285dbeb.tar.xz
ARM: OMAP3: PM: correct enable/disable of daisy io chain
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, based loosely on the "Sec 3.5.7.2.2 I/O Wake-Up Mechanism" section 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@ti.com> Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com> [paul@pwsan.com: modified commit message to clarify that these steps are based loosely on the TRM section, rather than documented exactly] Reviewed-by: Rajendra Nayak <rnayak@ti.com> [paul@pwsan.com: resolved new warnings from checkpatch] Signed-off-by: Paul Walmsley <paul@pwsan.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mach-omap2/pm34xx.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index a34023d..6d7f0d8 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -81,16 +81,17 @@ 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)