[openwrt/openwrt] mvebu: backport upstream patch to fix COMPHY reset

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/f6b46c9269a2e83e88b0a353a87812cd4837f97e

commit f6b46c9269a2e83e88b0a353a87812cd4837f97e
Author: Michal Hrusecky <michal.hrusecky at turris.com>
AuthorDate: Mon Jan 9 15:59:02 2023 +0100

    mvebu: backport upstream patch to fix COMPHY reset
    
    Upstream commit [1] included in the Linux kernel version 6.2 was
    backported to Linux kernels 6.1.4, 6.0.18. It should be possible that it
    is going to be backported even to the 5.15 series, but before it happens,
    let's include it here.
    
    It was discovered that on SOC Marvell Armada 3720, which is using e.g.
    Turris MOX, and if you are also using it with older ARM Trusted Firmware
    v1.5, it is not possible to detect connected USB 3.0 devices, but they
    are working just fine when connected with USB 2.0 cable. This patch
    fixes it.
    
    [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/phy/marvell/phy-mvebu-a3700-comphy.c?id=b01d622d76134e9401970ffd3fbbb9a7051f976a
    
    Reviewed-by: Robert Marko <robimarko at gmail.com>
    Signed-off-by: Michal Hrusecky <michal.hrusecky at turris.com>
    Signed-off-by: Josef Schlehofer <pepe.schlehofer at gmail.com>
    [improve commit description, added tag to the patch]
---
 ...-phy-mvebu-a3700-comphy-Reset-COMPHY-regi.patch | 50 ++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/target/linux/mvebu/patches-5.15/710-v6.2-phy-marvell-phy-mvebu-a3700-comphy-Reset-COMPHY-regi.patch b/target/linux/mvebu/patches-5.15/710-v6.2-phy-marvell-phy-mvebu-a3700-comphy-Reset-COMPHY-regi.patch
new file mode 100644
index 0000000000..a852dc1fc1
--- /dev/null
+++ b/target/linux/mvebu/patches-5.15/710-v6.2-phy-marvell-phy-mvebu-a3700-comphy-Reset-COMPHY-regi.patch
@@ -0,0 +1,50 @@
+From b01d622d76134e9401970ffd3fbbb9a7051f976a Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali at kernel.org>
+Date: Tue, 20 Sep 2022 14:11:54 +0200
+Subject: [PATCH] phy: marvell: phy-mvebu-a3700-comphy: Reset COMPHY registers
+ before USB 3.0 power on
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Turris MOX board with older ARM Trusted Firmware version v1.5 is not able
+to detect any USB 3.0 device connected to USB-A port on Mox-A module after
+commit 0a6fc70d76bd ("phy: marvell: phy-mvebu-a3700-comphy: Remove broken
+reset support"). On the other hand USB 2.0 devices connected to the same
+USB-A port are working fine.
+
+It looks as if the older firmware configures COMPHY registers for USB 3.0
+somehow incompatibly for kernel driver. Experiments show that resetting
+COMPHY registers via setting SFT_RST auto-clearing bit in COMPHY_SFT_RESET
+register fixes this issue.
+
+Reset the COMPHY in mvebu_a3700_comphy_usb3_power_on() function as a first
+step after selecting COMPHY lane and USB 3.0 function. With this change
+Turris MOX board can successfully detect USB 3.0 devices again.
+
+Before the above mentioned commit this reset was implemented in PHY reset
+method, so this is the reason why there was no issue with older firmware
+version then.
+
+Fixes: 0a6fc70d76bd ("phy: marvell: phy-mvebu-a3700-comphy: Remove broken reset support")
+Reported-by: Marek Behún <kabel at kernel.org>
+Signed-off-by: Pali Rohár <pali at kernel.org>
+Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki at wdc.com>
+Link: https://lore.kernel.org/r/20220920121154.30115-1-pali@kernel.org
+Signed-off-by: Vinod Koul <vkoul at kernel.org>
+---
+ drivers/phy/marvell/phy-mvebu-a3700-comphy.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/drivers/phy/marvell/phy-mvebu-a3700-comphy.c
++++ b/drivers/phy/marvell/phy-mvebu-a3700-comphy.c
+@@ -826,6 +826,9 @@ mvebu_a3700_comphy_usb3_power_on(struct
+ 	if (ret)
+ 		return ret;
+ 
++	/* COMPHY register reset (cleared automatically) */
++	comphy_lane_reg_set(lane, COMPHY_SFT_RESET, SFT_RST, SFT_RST);
++
+ 	/*
+ 	 * 0. Set PHY OTG Control(0x5d034), bit 4, Power up OTG module The
+ 	 * register belong to UTMI module, so it is set in UTMI phy driver.