i2c: npcm: Handle spurious interrupts

stable inclusion
from stable-v5.10.121
commit ebd4f37ac1e6440b3b2a81c751aacf1ed67a97a3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ebd4f37ac1e6440b3b2a81c751aacf1ed67a97a3



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[ Upstream commit e5222d40 ]

On some platforms in rare cases (1 to 100,000 transactions),
the i2c gets a spurious interrupt which means that we enter an interrupt
but in the interrupt handler we don't find any status bit that points to
the reason we got this interrupt.

This may be a case of a rare HW issue or signal integrity issue that is
still under investigation.

In order to overcome this we are doing the following:
1. Disable incoming interrupts in master mode only when slave mode is not
   enabled.
2. Clear end of busy (EOB) after every interrupt.
3. Clear other status bits (just in case since we found them cleared)
4. Return correct status during the interrupt that will finish the
   transaction.

On next xmit transaction if the bus is still busy the master will issue a
recovery process before issuing the new transaction.

Fixes: 56a1485b ("i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver")
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
Signed-off-by: Tyrone Ting <kfting@nuvoton.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>