leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

omap3: PM: enable UART3 module wakeups

Browse Source 
UART3 is in the PER powerdomain.  If PER goes idle/inactive
independently of CORE, for UART3 to wakeup it must have its wakeup
enable bits setup in PM_WKEN_PER.  This patch enables these bits.

The reason it works when PER and CORE work together is because when
CORE goes inactive/retention, the IOPAD wakeups are enabled and
trigger UART3 wakeup.

Without this patch, when the UART inactivity timer fires for UART3,
its clocks are disabled and it's unable to wakeup so will be unusable
until PER is awoken by another source.

Another way of testing is by keeping CORE on during suspend but
allowing PER to hit retention

  # echo 3 > /debug/pm_debug/core_pwrdm/suspend

then enter suspend

  # echo mem > /sys/power/state

Without this patch, UART3 will be unable to wakeup the system.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Kevin Hilman 2009-10-22 14:48:13 -07:00 committed by Tony Lindgren
parent 60dbd8c95f
commit b427f92f8c
1 changed files with 4 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/arm/mach-omap2/pm34xx.c
View File

@ -639,14 +639,15 @@ static void __init prcm_setup_regs(void)
prm_write_mod_reg(OMAP3430_IO_EN | OMAP3430_WKUP_EN,
OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);
/* Enable GPIO wakeups in PER */
/* Enable wakeups in PER */
prm_write_mod_reg(OMAP3430_EN_GPIO2 | OMAP3430_EN_GPIO3 |
OMAP3430_EN_GPIO4 | OMAP3430_EN_GPIO5 |
OMAP3430_EN_GPIO6, OMAP3430_PER_MOD, PM_WKEN);
OMAP3430_EN_GPIO6 | OMAP3430_EN_UART3,
OMAP3430_PER_MOD, PM_WKEN);
/* and allow them to wake up MPU */
prm_write_mod_reg(OMAP3430_GRPSEL_GPIO2 | OMAP3430_EN_GPIO3 |
OMAP3430_GRPSEL_GPIO4 | OMAP3430_EN_GPIO5 |
OMAP3430_GRPSEL_GPIO6,
OMAP3430_GRPSEL_GPIO6 | OMAP3430_EN_UART3,
OMAP3430_PER_MOD, OMAP3430_PM_MPUGRPSEL);
/* Don't attach IVA interrupts */