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Diffstat (limited to 'src/soc/amd/common/block/smbus/smbus_early_fch.c')
-rw-r--r--src/soc/amd/common/block/smbus/smbus_early_fch.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/src/soc/amd/common/block/smbus/smbus_early_fch.c b/src/soc/amd/common/block/smbus/smbus_early_fch.c
new file mode 100644
index 0000000000..3d04778b24
--- /dev/null
+++ b/src/soc/amd/common/block/smbus/smbus_early_fch.c
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <stdint.h>
+#include <amdblocks/acpimmio.h>
+#include <amdblocks/smbus.h>
+#include <soc/southbridge.h>
+
+void fch_smbus_init(void)
+{
+ /* 400 kHz smbus speed. */
+ const uint8_t smbus_speed = (66000000 / (400000 * 4));
+
+ pm_write8(SMB_ASF_IO_BASE, SMB_BASE_ADDR >> 8);
+ smbus_write8(SMBTIMING, smbus_speed);
+ /* Clear all SMBUS status bits */
+ smbus_write8(SMBHSTSTAT, SMBHST_STAT_CLEAR);
+ smbus_write8(SMBSLVSTAT, SMBSLV_STAT_CLEAR);
+ asf_write8(SMBHSTSTAT, SMBHST_STAT_CLEAR);
+ asf_write8(SMBSLVSTAT, SMBSLV_STAT_CLEAR);
+}