u-boot/board/freescale/ls1012aqds
Vladimir Oltean 7c2d5d1642 net: freescale: replace usage of phy-mode = "sgmii-2500" with "2500base-x"
After the discussion here:
https://lore.kernel.org/netdev/20210603143453.if7hgifupx5k433b@pali/

which resulted in this patch:
https://patchwork.kernel.org/project/netdevbpf/patch/20210704134325.24842-1-pali@kernel.org/

and many other discussions before it, notably:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/1512016235-15909-1-git-send-email-Bhaskar.Upadhaya@nxp.com/

it became apparent that nobody really knows what "SGMII 2500" is.
Certainly, Freescale/NXP hardware engineers name this protocol
"SGMII 2500" in the reference manuals, but the PCS devices do not
support any "SGMII" specific features when operating at the speed of
2500 Mbps, no in-band autoneg and no speed change via symbol replication
. So that leaves a fixed speed of 2500 Mbps using a coding of 8b/10b
with a SERDES lane frequency of 3.125 GHz. In fact, "SGMII 2500 without
in-band autoneg and at a fixed speed" is indistinguishable from
"2500base-x without in-band autoneg", which is precisely what these NXP
devices support.

So it just appears that "SGMII 2500" is an unclear name with no clear
definition that stuck.

As such, in the Linux kernel, the drivers which use this SERDES protocol
use the 2500base-x phy-mode.

This patch converts U-Boot to use 2500base-x too, or at least, as much
as it can.

Note that I would have really liked to delete PHY_INTERFACE_MODE_SGMII_2500
completely, but the mvpp2 driver seems to even distinguish between SGMII
2500 and 2500base-X. Namely, it enables in-band autoneg for one but not
the other, and forces flow control for one but not the other. This goes
back to the idea that maybe 2500base-X is a fiber protocol and SGMII-2500
is an MII protocol (connects a MAC to a PHY such as Aquantia), but the
two are practically indistinguishable through everything except use case.

NXP devices can support both use cases through an identical configuration,
for example RX flow control can be unconditionally enabled in order to
support rate adaptation performed by an Aquantia PHY. At least I can
find no indication in online documents published by Cisco which would
point towards "SGMII-2500" being an actual standard with an actual
definition, so I cannot say "yes, NXP devices support it".

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
2021-09-28 18:50:56 +03:00
..
eth.c net: freescale: replace usage of phy-mode = "sgmii-2500" with "2500base-x" 2021-09-28 18:50:56 +03:00
Kconfig net: pfe_eth: read PFE ESBC header flash with spi_flash_read API 2020-12-10 13:56:39 +05:30
ls1012aqds.c net: freescale: replace usage of phy-mode = "sgmii-2500" with "2500base-x" 2021-09-28 18:50:56 +03:00
ls1012aqds_pfe.h net: freescale: replace usage of phy-mode = "sgmii-2500" with "2500base-x" 2021-09-28 18:50:56 +03:00
ls1012aqds_qixis.h SPDX: Convert all of our single license tags to Linux Kernel style 2018-05-07 09:34:12 -04:00
MAINTAINERS board: ls1012aqds: Update MAINTAINERS 2021-03-05 10:25:42 +05:30
Makefile board: freescale: ls1012aqds: enable network support on ls1012aqds 2018-03-22 15:05:29 -05:00
README armv8: ls1012a: Add support of ls1012aqds board 2016-06-03 14:12:51 -07:00

Overview
--------
QorIQ LS1012A Development System (LS1012AQDS) is a high-performance
development platform, with a complete debugging environment.
The LS1012AQDS board supports the QorIQ LS1012A processor and is
optimized to support the high-bandwidth DDR3L memory and
a full complement of high-speed SerDes ports.

LS1012A SoC Overview
--------------------
Please refer arch/arm/cpu/armv8/fsl-layerscape/doc/README.soc for LS1012A
SoC overview.

LS1012AQDS board Overview
-----------------------
 - SERDES Connections, 4 lanes supporting:
      - PCI Express - 3.0
      - SGMII, SGMII 2.5
      - SATA 3.0
 - DDR Controller
     - 16-bit, 1 GB DDR3L SDRAM memory, running at data rates up to 1 GT/s
 - QSPI Controller
     - A dual 1:3 switch, NX3L4357GM,115 (U35) drives the QSPI chip-select
       signals to QSPI NOR flash memory (2 virtual banks) and the QSPI
       emulator
 - USB 3.0
    - One USB 3.0 controller with integrated PHY
    - One high-speed USB 3.0 port
 - USB 2.0
    - One USB 2.0 controller with ULPI interface
 - Two enhanced secure digital host controllers:
    - SDHC1 controller can be connected to onboard SDHC connector
    - SDHC2 controller: 1-/4-bit SD/MMC card supporting 1.8 V devices
 - 2 I2C controllers
 - One SATA onboard connectors
 - UART
 - 5 SAI
    - One SAI port with audio codec SGTL5000:
	• Provides MIC bias
	• Provides headphone and line output
    - One SAI port terminated at 2x6 header
    - Three SAI Tx/Rx ports terminated at 2x3 headers
 - ARM JTAG support

Booting Options
---------------
a) QSPI Flash Emu Boot
b) QSPI Flash 1
c) QSPI Flash 2

QSPI flash map
--------------
Images		| Size	|QSPI Flash Address
------------------------------------------
RCW + PBI	| 1MB	| 0x4000_0000
U-boot 		| 1MB	| 0x4010_0000
U-boot Env 	| 1MB	| 0x4020_0000
PPA FIT image	| 2MB	| 0x4050_0000
Linux ITB	| ~53MB | 0x40A0_0000