Re: [PATCH] platform/x86: serial-multi-instantiate: Don't require both I2C and SPI

From: Richard Fitzgerald
Date: Wed Aug 14 2024 - 09:13:40 EST


On 13/08/2024 12:21, Richard Fitzgerald wrote:
Change the Kconfig dependency to (I2C || SPI) so that it doesn't
require both bus subsystems to be enabled. Make a few small changes to
the code so that the code for a bus is only called if the bus is being
built.

When SPI support was added to serial-multi-instantiate it created a
dependency that both CONFIG_I2C and CONFIG_SPI must be enabled.
Typically they are, but there's no reason why this should be a
requirement. A specific kernel build could have only I2C devices or
only SPI devices. It should be possible to use serial-multi-instantiate
if only I2C or only SPI is enabled.

Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/platform/x86/Kconfig | 2 +-
.../platform/x86/serial-multi-instantiate.c | 32 ++++++++++++++-----
2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 665fa9524986..c286742b34ba 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -999,7 +999,7 @@ config TOPSTAR_LAPTOP
config SERIAL_MULTI_INSTANTIATE
tristate "Serial bus multi instantiate pseudo device driver"
- depends on I2C && SPI && ACPI
+ depends on (I2C || SPI) && ACPI

Please don't take this version.
It works better as:

depends on ACPI
depends on (I2C && !SPI) || (!I2C && SPI) || (I2C && SPI)

so if I2C or SPI =m then SERIAL_MULTI_INSTANTIATE must be
built as a module.

I will send a V2 with that change.