Change the Kconfig dependency so that it doesn't require both I2C and SPI
subsystems to be built. 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.
The dependency formula used is:
depends on (I2C && !SPI) || (!I2C && SPI) || (I2C && SPI)
The advantage of this approach is that if I2C=m or SPI=m then
SERIAL_MULTI_INSTANTIATE is limited to n/m.
Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
---
Changes from V1:
Use a different 'depends on' formula so that serial-multi-instantiate
must be built as a module if any dependencies are a module.
drivers/platform/x86/Kconfig | 3 +-
.../platform/x86/serial-multi-instantiate.c | 32 ++++++++++++++-----
2 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 665fa9524986..0dcf4d8eac56 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -999,7 +999,8 @@ config TOPSTAR_LAPTOP
config SERIAL_MULTI_INSTANTIATE
tristate "Serial bus multi instantiate pseudo device driver"
- depends on I2C && SPI && ACPI
+ depends on ACPI
+ depends on (I2C && !SPI) || (!I2C && SPI) || (I2C && SPI)
help
Some ACPI-based systems list multiple devices in a single ACPI
firmware-node. This driver will instantiate separate clients
diff --git a/drivers/platform/x86/serial-multi-instantiate.c b/drivers/platform/x86/serial-multi-instantiate.c
index 3be016cfe601..7c04cc9e5891 100644
--- a/drivers/platform/x86/serial-multi-instantiate.c
+++ b/drivers/platform/x86/serial-multi-instantiate.c
@@ -83,11 +83,15 @@ static int smi_get_irq(struct platform_device *pdev, struct acpi_device *adev,
static void smi_devs_unregister(struct smi *smi)
{
+#if IS_REACHABLE(CONFIG_I2C)
while (smi->i2c_num--)
i2c_unregister_device(smi->i2c_devs[smi->i2c_num]);
+#endif
- while (smi->spi_num--)
- spi_unregister_device(smi->spi_devs[smi->spi_num]);
+ if (IS_REACHABLE(CONFIG_SPI)) {
+ while (smi->spi_num--)
+ spi_unregister_device(smi->spi_devs[smi->spi_num]);
+ }
}
/**
@@ -258,9 +262,15 @@ static int smi_probe(struct platform_device *pdev)
switch (node->bus_type) {
case SMI_I2C:
- return smi_i2c_probe(pdev, smi, node->instances);
+ if (IS_REACHABLE(CONFIG_I2C))
+ return smi_i2c_probe(pdev, smi, node->instances);
+
+ return -ENODEV;
case SMI_SPI:
- return smi_spi_probe(pdev, smi, node->instances);
+ if (IS_REACHABLE(CONFIG_SPI))
+ return smi_spi_probe(pdev, smi, node->instances);
+
+ return -ENODEV;
case SMI_AUTO_DETECT:
/*
* For backwards-compatibility with the existing nodes I2C
@@ -270,10 +280,16 @@ static int smi_probe(struct platform_device *pdev)
* SpiSerialBus nodes that were previously ignored, and this
* preserves that behavior.
*/
- ret = smi_i2c_probe(pdev, smi, node->instances);
- if (ret != -ENOENT)
- return ret;
- return smi_spi_probe(pdev, smi, node->instances);
+ if (IS_REACHABLE(CONFIG_I2C)) {
+ ret = smi_i2c_probe(pdev, smi, node->instances);
+ if (ret != -ENOENT)
+ return ret;
+ }
+
+ if (IS_REACHABLE(CONFIG_SPI))
+ return smi_spi_probe(pdev, smi, node->instances);
+
+ return -ENODEV;
default:
return -EINVAL;
}
--
2.39.2
