linux_old1/drivers/mailbox
Dave Gerlach 8e3c595214 mailbox/omap: Add ti,mbox-send-noirq quirk to fix AM33xx CPU Idle
The mailbox framework controls the transmission queue and requires
either its controller implementations or clients to run the state
machine for the Tx queue. The OMAP mailbox controller uses a Tx-ready
interrupt as the equivalent of a Tx-done interrupt to run this Tx
queue state-machine.

The WkupM3 processor on AM33xx and AM43xx SoCs is used to offload
certain PM tasks, like doing the necessary operations for Device
PM suspend/resume or for entering lower c-states during cpuidle.

The CPUIdle on AM33xx requires the messages to be sent without
having to trigger the Tx-ready interrupts, as the interrupt
would immediately terminate the CPUIdle operation. Support for
this has been added by introducing a DT quirk, "ti,mbox-send-noirq"
and using it to modify the normal OMAP mailbox controller behavior
on the sub-mailboxes used to communicate with the WkupM3 remote
processor. This also requires the wkup_m3_ipc driver to adjust
its mailbox usage logic to run the Tx state machine.

NOTE:
- AM43xx does not communicate with WkupM3 for CPU Idle, so is
  not affected by this behavior. But, it uses the same IPC driver
  for PM suspend/resume functionality, so requires the quirk as
  well, because of changes to the common wkup_m3_ipc driver.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
[s-anna@ti.com: revise logic and update comments/patch description]
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
2015-10-23 11:19:27 +05:30
..
Kconfig mailbox: Add generic mechanism for testing Mailbox Controllers 2015-10-17 10:36:56 +05:30
Makefile mailbox: Add generic mechanism for testing Mailbox Controllers 2015-10-17 10:36:56 +05:30
arm_mhu.c Merge branch 'mailbox-for-next' of git://git.linaro.org/landing-teams/working/fujitsu/integration 2015-09-05 18:11:04 -07:00
bcm2835-mailbox.c mailbox: Drop owner assignment from platform_driver 2015-08-05 17:20:53 +05:30
mailbox-altera.c mailbox: Make mbox_chan_ops const 2015-05-12 09:18:16 +05:30
mailbox-sti.c mailbox: Fix a couple of trivial static checker issues 2015-10-17 10:36:56 +05:30
mailbox-test.c mailbox: mailbox-test: Correctly repair Sparse warnings 2015-10-23 11:19:21 +05:30
mailbox.c mailbox: switch to hrtimer for tx_complete polling 2015-08-10 14:29:27 +05:30
mailbox.h Mailbox: Add support for Platform Communication Channel 2014-11-27 12:51:09 +05:30
omap-mailbox.c mailbox/omap: Add ti,mbox-send-noirq quirk to fix AM33xx CPU Idle 2015-10-23 11:19:27 +05:30
pcc.c PCC: fix dereference of ERR_PTR 2015-10-16 10:46:07 +05:30
pl320-ipc.c arm: use subsys_initcall in non-modular pl320 IPC code 2015-06-16 14:12:35 -04:00