[PATCH v1 1/1] mfd: intel-m10-bmc: expose mac address and count

[Russ Weight]

Create two sysfs entries for exposing the MAC address
and count from the MAX10 BMC register space.

Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
---
 .../ABI/testing/sysfs-driver-intel-m10-bmc    | 20 +++++++++
 drivers/mfd/intel-m10-bmc.c                   | 43 +++++++++++++++++++
 include/linux/mfd/intel-m10-bmc.h             |  9 ++++
 3 files changed, 72 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc b/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc
index 979a2d62513f..c4febaefe0a7 100644
--- a/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc
+++ b/Documentation/ABI/testing/sysfs-driver-intel-m10-bmc
@@ -13,3 +13,23 @@ Contact:	Xu Yilun <yilun.xu@xxxxxxxxx>
 Description:	Read only. Returns the firmware version of Intel MAX10
 		BMC chip.
 		Format: "0x%x".
+
+What:		/sys/bus/spi/devices/.../mac_address
+Date:		December 2020
+KernelVersion:  5.11
+Contact:	Russ Weight <russell.h.weight@xxxxxxxxx>
+Description:	Read only. Returns the base mac address assigned to
+		the board managed by the Intel MAX10 BMC. It is
+		stored in flash and is mirrored in the MAX10 BMC
+		register space.
+		Format: "%02x:%02x:%02x:%02x:%02x:%02x".
+
+What:		/sys/bus/spi/devices/.../mac_count
+Date:		December 2020
+KernelVersion:  5.11
+Contact:	Russ Weight <russell.h.weight@xxxxxxxxx>
+Description:	Read only. Returns the number of mac addresses
+		assigned to the board managed by the Intel MAX10
+		BMC. This value is stored in flash and is mirrored
+		in the MAX10 BMC register space.
+		Format: "%u".
diff --git a/drivers/mfd/intel-m10-bmc.c b/drivers/mfd/intel-m10-bmc.c
index b84579b7b4f0..90720e84900e 100644
--- a/drivers/mfd/intel-m10-bmc.c
+++ b/drivers/mfd/intel-m10-bmc.c
@@ -60,9 +60,52 @@ static ssize_t bmcfw_version_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(bmcfw_version);
 
+static ssize_t mac_address_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct intel_m10bmc *max10 = dev_get_drvdata(dev);
+	unsigned int macaddr1, macaddr2;
+	int ret;
+
+	ret = m10bmc_sys_read(max10, M10BMC_MACADDR1, &macaddr1);
+	if (ret)
+		return ret;
+
+	ret = m10bmc_sys_read(max10, M10BMC_MACADDR2, &macaddr2);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%02x:%02x:%02x:%02x:%02x:%02x\n",
+		       (u8)FIELD_GET(M10BMC_MAC_BYTE1, macaddr1),
+		       (u8)FIELD_GET(M10BMC_MAC_BYTE2, macaddr1),
+		       (u8)FIELD_GET(M10BMC_MAC_BYTE3, macaddr1),
+		       (u8)FIELD_GET(M10BMC_MAC_BYTE4, macaddr1),
+		       (u8)FIELD_GET(M10BMC_MAC_BYTE5, macaddr2),
+		       (u8)FIELD_GET(M10BMC_MAC_BYTE6, macaddr2));
+}
+static DEVICE_ATTR_RO(mac_address);
+
+static ssize_t mac_count_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct intel_m10bmc *max10 = dev_get_drvdata(dev);
+	unsigned int macaddr2;
+	int ret;
+
+	ret = m10bmc_sys_read(max10, M10BMC_MACADDR2, &macaddr2);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%u\n",
+		       (u8)FIELD_GET(M10BMC_MAC_COUNT, macaddr2));
+}
+static DEVICE_ATTR_RO(mac_count);
+
 static struct attribute *m10bmc_attrs[] = {
 	&dev_attr_bmc_version.attr,
 	&dev_attr_bmcfw_version.attr,
+	&dev_attr_mac_address.attr,
+	&dev_attr_mac_count.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(m10bmc);
diff --git a/include/linux/mfd/intel-m10-bmc.h b/include/linux/mfd/intel-m10-bmc.h
index c8ef2f1654a4..2279e34f0814 100644
--- a/include/linux/mfd/intel-m10-bmc.h
+++ b/include/linux/mfd/intel-m10-bmc.h
@@ -15,6 +15,15 @@
 
 /* Register offset of system registers */
 #define NIOS2_FW_VERSION		0x0
+#define M10BMC_MACADDR1			0x10
+#define M10BMC_MAC_BYTE4		GENMASK(7, 0)
+#define M10BMC_MAC_BYTE3		GENMASK(15, 8)
+#define M10BMC_MAC_BYTE2		GENMASK(23, 16)
+#define M10BMC_MAC_BYTE1		GENMASK(31, 24)
+#define M10BMC_MACADDR2			0x14
+#define M10BMC_MAC_BYTE6		GENMASK(7, 0)
+#define M10BMC_MAC_BYTE5		GENMASK(15, 8)
+#define M10BMC_MAC_COUNT		GENMASK(23, 16)
 #define M10BMC_TEST_REG			0x3c
 #define M10BMC_BUILD_VER		0x68
 #define M10BMC_VER_MAJOR_MSK		GENMASK(23, 16)
-- 
2.25.1