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

[Tom Rix]

On 12/2/20 10:26 AM, Russ Weight wrote:
>
> On 12/2/20 5:44 AM, Tom Rix wrote:
>> On 12/1/20 12:36 PM, Russ Weight wrote:
>>> 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;
>>> +
>> The mac_count implies there are more than 1 mac address.
>>
>> This logic looks like could only do one.
>>
>> How are the 2nd, 3rd  etc. mac addresses found ?
> The MAC addresses assigned to the card are sequential. The base MAC
> address is exposed through the mac_address sysfs entry. Add 1 to
> that MAC address for the second MAC address, etc.

Ok.

Please capture this in the docs section above.

>>> +	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));
>> consider using sysfs_emit over sprintf
> Yes. I'll change to sysfs_emit and resubmit.
>
> Thanks,
> - Russ
>> Tom
>>
>>> +}
>>> +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)