mailbox: arm_mhuv2: Fix a bug for mhuv2_sender_interrupt

Message Handling Unit version is v2.1.

When arm_mhuv2 working with the data protocol transfer mode.
We have split one mhu into two channels, and every channel
include four channel windows, the two channels share
one gic spi interrupt.

There is a problem with the sending scenario.

The first channel will take up 0-3 channel windows, and the second
channel take up 4-7 channel windows. When the first channel send the
data, and the receiver will clear all the four channels status.
Although we only enabled the interrupt on the last channel window with
register CH_INT_EN,the register CHCOMB_INT_ST0 will be 0xf, not be 0x8.
Currently we just clear the last channel windows int status with the
data proctol mode.So after that,the CHCOMB_INT_ST0 status will be 0x7,
not be the 0x0.

Then the second channel send the data, the receiver read the
data, clear all the four channel windows status, trigger the sender
interrupt. But currently the CHCOMB_INT_ST0 register will be 0xf7,
get_irq_chan_comb function will always return the first channel.

So this patch clear all channel windows int status to avoid this interrupt
confusion.

Signed-off-by: Xiaowu.ding <xiaowu.ding@jaguarmicro.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: arm_mhuv2: Fix return value check in mhuv2_probe()

If devm_of_iomap() fails, it returns ERR_PTR() and never
return NULL, so replace NULL pointer check with IS_ERR()
to fix this problem.

Fixes: 5a6338cce9f4 ("mailbox: arm_mhuv2: Add driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: correct kerneldoc

Correct kerneldoc warnings like:

drivers/mailbox/arm_mhu_db.c:47:
warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
drivers/mailbox/qcom-ipcc.c:58:
warning: Function parameter or member 'num_chans' not described in 'qcom_ipcc'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: arm_mhuv2: Skip calling kfree() with invalid pointer

It is possible that 'data' passed to kfree() is set to a error value
instead of allocated space. Make sure it doesn't get called with invalid
pointer.

Fixes: 5a6338cce9f4 ("mailbox: arm_mhuv2: Add driver")
Cc: v5.11 <stable@vger.kernel.org> # v5.11
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: arm_mhuv2: make remove callback return void

My build tests failed to catch that amba driver that would have needed
adaption in commit 3fd269e74f2f ("amba: Make the remove callback return
void"). Change the remove function to make the driver build again.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 3fd269e74f2f ("amba: Make the remove callback return void")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

mailbox: arm_mhuv2: Fix sparse warnings

This patch fixes a bunch of sparse warnings in the newly added arm_mhuv2
driver.

drivers/mailbox/arm_mhuv2.c:506:24: warning: incorrect type in argument 1 (different address spaces)
drivers/mailbox/arm_mhuv2.c:506:24: expected void const volatile [noderef] __iomem *addr
drivers/mailbox/arm_mhuv2.c:506:24: got unsigned int [usertype] *
drivers/mailbox/arm_mhuv2.c:547:42: warning: incorrect type in argument 2 (different address spaces)
drivers/mailbox/arm_mhuv2.c:547:42: expected unsigned int [usertype] *reg
drivers/mailbox/arm_mhuv2.c:547:42: got unsigned int [noderef] __iomem *
drivers/mailbox/arm_mhuv2.c:625:42: warning: incorrect type in argument 2 (different address spaces)
drivers/mailbox/arm_mhuv2.c:625:42: expected unsigned int [usertype] *reg
drivers/mailbox/arm_mhuv2.c:625:42: got unsigned int [noderef] __iomem *
drivers/mailbox/arm_mhuv2.c:972:24: warning: dereference of noderef expression
drivers/mailbox/arm_mhuv2.c:973:22: warning: dereference of noderef expression
drivers/mailbox/arm_mhuv2.c:993:25: warning: dereference of noderef expression
drivers/mailbox/arm_mhuv2.c:1026:24: warning: dereference of noderef expression
drivers/mailbox/arm_mhuv2.c:1027:22: warning: dereference of noderef expression
drivers/mailbox/arm_mhuv2.c:1048:17: warning: dereference of noderef expression

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

ARM: 9055/1: mailbox: arm_mhuv2: make remove callback return void

My build tests failed to catch that amba driver that would have needed
adaption in commit 3fd269e74f2f ("amba: Make the remove callback return
void"). Change the remove function to make the driver build again.

Link: https://lore.kernel.org/r/20210202194308.jm66vblqjwr5wo6v@pengutronix.de

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 3fd269e74f2f ("amba: Make the remove callback return void")
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

mailbox: arm_mhuv2: Add driver

This adds driver for the ARM MHUv2 (Message Handling Unit) mailbox
controller.

This is based on the accepted DT bindings of the controller and supports
combination of both transport protocols, i.e. doorbell and data-transfer.

Transmitting and receiving data through the mailbox framework is done
through struct arm_mhuv2_mbox_msg.

Based on the initial work done by Morten Borup Petersen from ARM.

Co-developed-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Tested-by: Usama Arif <usama.arif@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>