From c242193ca42efc5d89173441bb5c9be69208867e Mon Sep 17 00:00:00 2001 From: Patrick Rudolph Date: Sat, 31 Jan 2026 07:23:55 +0100 Subject: [PATCH] device/smbus: Add i2c_eeprom_read MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Expose the existing i2c block read functionality usually used in romstage to the smbus_bus_operations for use in ramstage. This allows faster reading of I2C EEPROM in ramstage. TEST=Can read I2C EEPROM on Lenovo X220 using I2C block read. Change-Id: I1264f17317c3095f9661b0ab6aa3124a00ce86c5 Signed-off-by: Patrick Rudolph Reviewed-on: https://review.coreboot.org/c/coreboot/+/91028 Reviewed-by: Kyösti Mälkki Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel Reviewed-by: Alicja Michalska --- src/device/smbus_ops.c | 8 ++++++++ src/include/device/smbus.h | 2 ++ src/southbridge/intel/common/smbus_ops.c | 21 +++++++++++++++++---- 3 files changed, 27 insertions(+), 4 deletions(-) diff --git a/src/device/smbus_ops.c b/src/device/smbus_ops.c index d08965c7e0..0bff636c62 100644 --- a/src/device/smbus_ops.c +++ b/src/device/smbus_ops.c @@ -35,3 +35,11 @@ int smbus_block_write(struct device *dev, u8 cmd, u8 bytes, const u8 *buffer) return ops_smbus_bus(get_pbus_smbus(dev))->block_write(dev, cmd, bytes, buffer); } + +int smbus_i2c_eeprom_read(struct device *dev, u8 cmd, u8 bytes, u8 *buffer) +{ + CHECK_PRESENCE(i2c_eeprom_read); + + return ops_smbus_bus(get_pbus_smbus(dev))->i2c_eeprom_read(dev, cmd, + bytes, buffer); +} diff --git a/src/include/device/smbus.h b/src/include/device/smbus.h index 171e304472..02ddec661a 100644 --- a/src/include/device/smbus.h +++ b/src/include/device/smbus.h @@ -16,6 +16,7 @@ struct smbus_bus_operations { int (*block_read)(struct device *dev, u8 cmd, u8 bytes, u8 *buffer); int (*block_write)(struct device *dev, u8 cmd, u8 bytes, const u8 *buffer); + int (*i2c_eeprom_read)(struct device *dev, u8 offset, u8 bytes, u8 *buffer); }; static inline const struct smbus_bus_operations *ops_smbus_bus(struct bus *bus) @@ -54,6 +55,7 @@ static inline int smbus_write_byte(struct device *const dev, u8 addr, u8 val) int smbus_block_read(struct device *dev, u8 cmd, u8 bytes, u8 *buffer); int smbus_block_write(struct device *dev, u8 cmd, u8 bytes, const u8 *buffer); +int smbus_i2c_eeprom_read(struct device *dev, u8 cmd, u8 bytes, u8 *buffer); #endif #endif /* DEVICE_SMBUS_H */ diff --git a/src/southbridge/intel/common/smbus_ops.c b/src/southbridge/intel/common/smbus_ops.c index 8542ba3d04..242603765a 100644 --- a/src/southbridge/intel/common/smbus_ops.c +++ b/src/southbridge/intel/common/smbus_ops.c @@ -56,11 +56,24 @@ static int lsmbus_block_read(struct device *dev, u8 cmd, u8 bytes, u8 *buf) return do_smbus_block_read(res->base, device, cmd, bytes, buf); } +static int lsmbus_i2c_eeprom_read(struct device *dev, u8 offset, u8 bytes, u8 *buf) +{ + u16 device; + struct resource *res; + struct bus *pbus; + + device = dev->path.i2c.device; + pbus = get_pbus_smbus(dev); + res = find_resource(pbus->dev, PCI_BASE_ADDRESS_4); + return do_i2c_eeprom_read(res->base, device, offset, bytes, buf); +} + struct smbus_bus_operations lops_smbus_bus = { - .read_byte = lsmbus_read_byte, - .write_byte = lsmbus_write_byte, - .block_read = lsmbus_block_read, - .block_write = lsmbus_block_write, + .read_byte = lsmbus_read_byte, + .write_byte = lsmbus_write_byte, + .block_read = lsmbus_block_read, + .block_write = lsmbus_block_write, + .i2c_eeprom_read = lsmbus_i2c_eeprom_read, }; void smbus_read_resources(struct device *dev)