[PATCH 0/2] Support updating the PCIe3 PHY firmware on RK3568

[Shawn Lin]

The RK3568 PCIe3 PHY contains a small controller that runs microcode
from an internal SRAM. The microcode present in the PHY is not always
the latest one; with a stale version the PHY may fail to establish a
stable link or come up with other issues that are otherwise very hard
to diagnose from the host side.

The firmware stays optional: when firmware-name is not described in DT
(older DTBs) or the file cannot be requested, the driver keeps the
existing behaviour and runs with the microcode already present in the
PHY, so there is no new hard dependency for existing boards.

Patch 2 for the PHY driver depends on a pending patch that fixes another
issue if anyone wants to apply this series for test:

lore.kernel.org/linux-rockchip/1792286036-208067-1-git-send-email-shawn.lin at rock-chips.com/


The required firmware file is available in the rockchip directory of
the linux-firmware repository:

  https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git

Load firmware during kernel compilation using the extra firmware assignment:

CONFIG_EXTRA_FIRMWARE="rockchip/pcie3-t22-c8g2-1.6.3-202a-p7.fw"
CONFIG_EXTRA_FIRMWARE_DIR="/home/lt/linux-firmware"

Tested on a RK3568 EVB1 with a PCIe3 x2 NVMe SSD, the firmware is loaded
and the link comes up:

  phy phy-fe8c0000.phy.0: lane number 0, val 1
  rockchip-snps-pcie3-phy fe8c0000.phy: loaded PHY firmware rockchip/pcie3-t22-c8g2-1.6.3-202a-p7.fw, size 16384
  rockchip-dw-pcie 3c0800000.pcie: host bridge /pcie at fe280000 ranges:
  ...
  pci 0002:21:00.0: [1e0f:0009] type 00 class 0x010802 PCIe Endpoint
  pci 0002:21:00.0: BAR 0 [mem 0x00000000-0x00003fff 64bit]
  pci 0002:21:00.0: 15.752 Gb/s available PCIe bandwidth, limited by 8.0 GT/s PCIe x2 link at 0002:20:00.0 (capable of 31.504 Gb/s with 8.0 GT/s PCIe x4 link)
  pci 0002:21:00.0: ASPM: default states L1



Shawn Lin (2):
  dt-bindings: phy: rockchip,pcie3-phy: Document firmware-name
  phy: rockchip: snps-pcie3: Load updated PHY firmware on RK3568

 .../bindings/phy/rockchip,pcie3-phy.yaml           |   6 ++
 drivers/phy/rockchip/phy-rockchip-snps-pcie3.c     | 101 ++++++++++++++++++++-
 2 files changed, 105 insertions(+), 2 deletions(-)

-- 
2.7.4