utils: Add the omnia-eeprom utility

Add a new utility, `omnia-eeprom`, which can be used to print / set
EEPROM fields on Turris Omnia.

One example when this utility might be useful is if the board
experiences random crashes due to newer versions of the DDR training
algorithm in newer U-Boot. The user can change the DDR speed from 1600K
to 1333H to solve these issues, with

  ```
  omnia-eeprom set ddr_speed 1333H
  ```

Signed-off-by: Marek Behún <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/16264
Signed-off-by: Robert Marko <[email protected]>
(cherry picked from commit 749a43325b98afe4430fa7e2f23ac3ee44791ad6)
Link: https://github.com/openwrt/openwrt/pull/17097
Signed-off-by: Petr Štetiar <[email protected]>

package/utils/omnia-eeprom/Makefile

@@ -0,0 +1,56 @@
+#
+# Copyright (C) 2024 Marek Behún <[email protected]>
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=omnia-eeprom
+PKG_VERSION:=0.1
+PKG_RELEASE:=1
+
+PKG_SOURCE_SUBDIR:=$(PKG_NAME)-v$(PKG_VERSION)
+PKG_SOURCE:=$(PKG_NAME)-v$(PKG_VERSION).tar.bz2
+PKG_SOURCE_URL:=https://gitlab.nic.cz/turris/omnia-eeprom/-/archive/v$(PKG_VERSION)/
+PKG_HASH:=6f949d0b8080adca8bae088774ce615b563ba6ec2807cce97ee6769b4eee7bbf
+
+PKG_MAINTAINER:=Marek Behun <[email protected]>
+PKG_LICENSE:=GPL-2.0-or-later
+
+PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_SOURCE_SUBDIR)
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/omnia-eeprom
+  SECTION:=utils
+  CATEGORY:=Utilities
+  URL:=https://gitlab.nic.cz/turris/omnia-eeprom
+  TITLE:=CZ.NIC Turris Omnia EEPROM accessing utility
+  DEPENDS:=@TARGET_mvebu_cortexa9_DEVICE_cznic_turris-omnia +kmod-eeprom-at24
+endef
+
+define Package/omnia-eeprom/description
+This package contains the omnia-eeprom utility, which allows you to display
+and update EEPROM fields on the Turris Omnia router.
+The EEPROM is normally not meant to be updated by users, but there are some
+exceptions where it might be useful.
+One such example is to change the DDR3 speed from the default 1600K mode to
+1333H mode, in order to solve random crashes that occur on some boards with
+newer versions of the U-Boot bootloader (because of bugs in newer versions of
+the DDR training algorithm).
+endef
+
+MAKE_VARS += OMNIA_EEPROM_VERSION="v$(PKG_VERSION)"
+
+TARGET_CFLAGS += -Wall
+
+Build/Compile = $(Build/Compile/Default)
+
+define Package/omnia-eeprom/install
+	$(INSTALL_DIR) $(1)/usr/bin
+	$(INSTALL_BIN) $(PKG_BUILD_DIR)/omnia-eeprom $(1)/usr/bin/
+endef
+
+$(eval $(call BuildPackage,omnia-eeprom))

target/linux/mvebu/image/cortexa9.mk

@@ -107,7 +107,8 @@ define Device/cznic_turris-omnia
     mkf2fs e2fsprogs kmod-fs-vfat kmod-nls-cp437 kmod-nls-iso8859-1 \
     wpad-basic-mbedtls kmod-ath9k kmod-ath10k-ct ath10k-firmware-qca988x-ct \
     kmod-mt7915-firmware partx-utils kmod-i2c-mux-pca954x kmod-leds-turris-omnia \
-    kmod-turris-omnia-mcu kmod-gpio-button-hotplug omnia-mcu-firmware omnia-mcutool
+    kmod-turris-omnia-mcu kmod-gpio-button-hotplug omnia-eeprom omnia-mcu-firmware \
+    omnia-mcutool
   IMAGES := sysupgrade.img.gz
   IMAGE/sysupgrade.img.gz := boot-scr | boot-img | sdcard-img | gzip | append-metadata
   SUPPORTED_DEVICES += armada-385-turris-omnia