southbridge/intel/common: Add Process Call
Add functionality to use process call cycle. It can be used to
write/read data to/from e.g. EEPROM attached to SMBus Controller
via I2C.
Tested on:
* C246
Change-Id: Ifdac6cf70a4ce744601f5d152a83d2125ea88360
Signed-off-by: Christian Walter <christian.walter@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39875
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/southbridge/intel/common/smbus.c b/src/southbridge/intel/common/smbus.c
index 95c2fd0..8b19b7d 100644
--- a/src/southbridge/intel/common/smbus.c
+++ b/src/southbridge/intel/common/smbus.c
@@ -33,6 +33,7 @@
#define I801_BYTE (1 << 2)
#define I801_BYTE_DATA (2 << 2)
#define I801_WORD_DATA (3 << 2)
+#define I801_PROCESS_CALL (4 << 2)
#define I801_BLOCK_DATA (5 << 2)
#define I801_I2C_BLOCK_DATA (6 << 2) /* ICH5 and later */
@@ -391,6 +392,42 @@
return ret;
}
+/*
+ * The caller is responsible of settings HOSTC I2C_EN bit prior to making this
+ * call!
+ */
+int do_smbus_process_call(uintptr_t base, u8 device, u8 cmd, u16 data, u16 *buf)
+{
+ int ret;
+
+ /* Set up for process call */
+ ret = setup_command(base, I801_PROCESS_CALL, XMIT_WRITE(device));
+ if (ret < 0)
+ return ret;
+
+ /* cmd will only be send if I2C_EN is zero */
+ host_outb(base, SMBHSTCMD, cmd);
+
+ host_outb(base, SMBHSTDAT0, data & 0x00ff);
+ host_outb(base, SMBHSTDAT1, (data & 0xff00) >> 8);
+
+ /* Start the command */
+ ret = execute_command(base);
+ if (ret < 0)
+ return ret;
+
+ /* Poll for transaction completion */
+ ret = complete_command(base);
+ if (ret < 0)
+ return ret;
+
+ /* Read results of transaction */
+ *buf = host_inb(base, SMBHSTDAT0);
+ *buf |= (host_inb(base, SMBHSTDAT1) << 8);
+
+ return ret;
+}
+
int do_smbus_block_write(uintptr_t base, u8 device, u8 cmd, const size_t bytes, const u8 *buf)
{
int ret;