[PATCH v3 2/2] i2c: piix4: Register SPDs

From: Thomas Weißschuh
Date: Tue Jul 09 2024 - 13:35:54 EST


The piix4 I2C bus can carry SPDs, register them if present.
Only look on bus 0, as this is where the SPDs seem to be located.

Only the first 8 slots are supported. If the system has more,
then these will not be visible.

The AUX bus can not be probed as on some platforms it reports all
devices present and all reads return "0".
This would allow the ee1004 to be probed incorrectly.

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/i2c/busses/Kconfig | 1 +
drivers/i2c/busses/i2c-piix4.c | 4 ++++
2 files changed, 5 insertions(+)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index fe6e8a1bb607..ff66e883b348 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -195,6 +195,7 @@ config I2C_ISMT
config I2C_PIIX4
tristate "Intel PIIX4 and compatible (ATI/AMD/Serverworks/Broadcom/SMSC)"
depends on PCI && HAS_IOPORT
+ select I2C_SMBUS
help
If you say yes to this option, support will be included for the Intel
PIIX4 family of mainboard I2C interfaces. Specifically, the following
diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 6a0392172b2f..14752d946f58 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -29,6 +29,7 @@
#include <linux/stddef.h>
#include <linux/ioport.h>
#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
#include <linux/slab.h>
#include <linux/dmi.h>
#include <linux/acpi.h>
@@ -982,6 +983,9 @@ static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
return retval;
}

+ if (port == 0)
+ i2c_register_spd(adap);
+
*padap = adap;
return 0;
}

--
2.45.2