board: wexler: qc750: add WEXLER Tab 7t support

WEXLER Tab 7t is a mini tablet computer developed by WEXLER that
runs the Android operating system. The device features a 7.0-inch
(180 mm) HD display, an Nvidia Tegra 3 quad-core chip, 1 GB of RAM,
8, 16 or 32 GB of storage that can be supplemented with a microSDXC
card giving up to 64 GB of additional storage and a full size USB
port.

Tested-by: Maksim Kurnosenko <asusx2@mail.ru>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>

arch/arm/dts/Makefile

@@ -125,6 +125,7 @@ dtb-$(CONFIG_ARCH_TEGRA) += \
 	tegra30-lg-p880.dtb \
 	tegra30-lg-p895.dtb \
 	tegra30-tec-ng.dtb \
+	tegra30-wexler-qc750.dtb \
 	tegra114-dalmore.dtb \
 	tegra124-apalis.dtb \
 	tegra124-jetson-tk1.dtb \

arch/arm/mach-tegra/tegra30/Kconfig

@@ -28,6 +28,10 @@ config TARGET_GROUPER
 	bool "Asus and Google Grouper board"
 	select BOARD_LATE_INIT
 
+config TARGET_QC750
+	bool "Wexler QC750 board"
+	select BOARD_LATE_INIT
+
 config TARGET_TEC_NG
 	bool "Avionic Design TEC-NG board"
 	select BOARD_LATE_INIT
@@ -51,6 +55,7 @@ source "board/nvidia/cardhu/Kconfig"
 source "board/toradex/colibri_t30/Kconfig"
 source "board/htc/endeavoru/Kconfig"
 source "board/asus/grouper/Kconfig"
+source "board/wexler/qc750/Kconfig"
 source "board/avionic-design/tec-ng/Kconfig"
 source "board/asus/transformer-t30/Kconfig"
 source "board/lg/x3-t30/Kconfig"

board/wexler/qc750/Kconfig

@@ -0,0 +1,12 @@
+if TARGET_QC750
+
+config SYS_BOARD
+	default "qc750"
+
+config SYS_VENDOR
+	default "wexler"
+
+config SYS_CONFIG_NAME
+	default "qc750"
+
+endif

board/wexler/qc750/MAINTAINERS

@@ -0,0 +1,7 @@
+QC750 BOARD
+M:	Svyatoslav Ryhel <clamor95@gmail.com>
+S:	Maintained
+F:	board/wexler/qc750/
+F:	configs/qc750_defconfig
+F:	doc/board/wexler/qc750.rst
+F:	include/configs/qc750.h

board/wexler/qc750/Makefile

@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+#  (C) Copyright 2010-2012
+#  NVIDIA Corporation <www.nvidia.com>
+#
+#  (C) Copyright 2023
+#  Svyatoslav Ryhel <clamor95@gmail.com>
+
+obj-$(CONFIG_SPL_BUILD) += qc750-spl.o
+
+obj-y += qc750.o

board/wexler/qc750/qc750-spl.c

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  T30 QC750 SPL stage configuration
+ *
+ *  (C) Copyright 2010-2013
+ *  NVIDIA Corporation <www.nvidia.com>
+ *
+ *  (C) Copyright 2023
+ *  Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#include <asm/arch/tegra.h>
+#include <asm/arch-tegra/tegra_i2c.h>
+#include <linux/delay.h>
+
+#define MAX77663_I2C_ADDR		(0x3c << 1)
+
+#define MAX77663_REG_SD0		0x16
+#define MAX77663_REG_SD0_DATA		(0x2100 | MAX77663_REG_SD0)
+#define MAX77663_REG_SD1		0x17
+#define MAX77663_REG_SD1_DATA		(0x3000 | MAX77663_REG_SD1)
+#define MAX77663_REG_LDO4		0x2b
+#define MAX77663_REG_LDO4_DATA		(0xE000 | MAX77663_REG_LDO4)
+
+#define MAX77663_REG_GPIO4		0x3a
+#define MAX77663_REG_GPIO4_DATA		(0x0100 | MAX77663_REG_GPIO4)
+
+void pmic_enable_cpu_vdd(void)
+{
+	/* Set VDD_CORE to 1.200V. */
+	tegra_i2c_ll_write(MAX77663_I2C_ADDR, MAX77663_REG_SD1_DATA);
+
+	udelay(1000);
+
+	/* Bring up VDD_CPU to 1.0125V. */
+	tegra_i2c_ll_write(MAX77663_I2C_ADDR, MAX77663_REG_SD0_DATA);
+	udelay(1000);
+
+	/* Bring up VDD_RTC to 1.200V. */
+	tegra_i2c_ll_write(MAX77663_I2C_ADDR, MAX77663_REG_LDO4_DATA);
+	udelay(10 * 1000);
+
+	/* Set 32k-out gpio state */
+	tegra_i2c_ll_write(MAX77663_I2C_ADDR, MAX77663_REG_GPIO4_DATA);
+}

board/wexler/qc750/qc750.c

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  (C) Copyright 2010-2013
+ *  NVIDIA Corporation <www.nvidia.com>
+ *
+ *  (C) Copyright 2023
+ *  Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#include <fdt_support.h>
+
+#if defined(CONFIG_OF_LIBFDT) && defined(CONFIG_OF_BOARD_SETUP)
+int ft_board_setup(void *blob, struct bd_info *bd)
+{
+	/* Remove TrustZone nodes */
+	fdt_del_node_and_alias(blob, "/firmware");
+	fdt_del_node_and_alias(blob, "/reserved-memory/trustzone@bfe00000");
+
+	return 0;
+}
+#endif

configs/qc750_defconfig

@@ -0,0 +1,81 @@
+CONFIG_ARM=y
+CONFIG_ARCH_TEGRA=y
+CONFIG_SUPPORT_PASSING_ATAGS=y
+CONFIG_CMDLINE_TAG=y
+CONFIG_INITRD_TAG=y
+CONFIG_TEXT_BASE=0x80110000
+CONFIG_NR_DRAM_BANKS=2
+CONFIG_ENV_SIZE=0x3000
+CONFIG_ENV_OFFSET=0xFFFFD000
+CONFIG_DEFAULT_DEVICE_TREE="tegra30-wexler-qc750"
+CONFIG_SPL_TEXT_BASE=0x80108000
+CONFIG_SPL_STACK=0x800ffffc
+CONFIG_TEGRA30=y
+CONFIG_TARGET_QC750=y
+CONFIG_TEGRA_ENABLE_UARTD=y
+CONFIG_CMD_EBTUPDATE=y
+CONFIG_SYS_LOAD_ADDR=0x82000000
+CONFIG_BUTTON_CMD=y
+CONFIG_BOOTDELAY=0
+CONFIG_AUTOBOOT_KEYED=y
+CONFIG_AUTOBOOT_KEYED_CTRLC=y
+CONFIG_OF_BOARD_SETUP=y
+CONFIG_OF_SYSTEM_SETUP=y
+CONFIG_BOOTCOMMAND="bootflow scan; poweroff"
+CONFIG_SYS_PBSIZE=2084
+CONFIG_SPL_FOOTPRINT_LIMIT=y
+CONFIG_SPL_MAX_FOOTPRINT=0x8000
+# CONFIG_SPL_SHARES_INIT_SP_ADDR is not set
+CONFIG_SPL_SYS_MALLOC=y
+CONFIG_SPL_HAS_CUSTOM_MALLOC_START=y
+CONFIG_SPL_CUSTOM_SYS_MALLOC_ADDR=0x80090000
+CONFIG_SPL_SYS_MALLOC_SIZE=0x10000
+CONFIG_SYS_PROMPT="Tegra30 (QC750) # "
+# CONFIG_CMD_BOOTEFI_BOOTMGR is not set
+CONFIG_CMD_BOOTMENU=y
+# CONFIG_CMD_IMI is not set
+CONFIG_CMD_GPIO=y
+CONFIG_CMD_GPT=y
+CONFIG_CMD_GPT_RENAME=y
+CONFIG_CMD_I2C=y
+CONFIG_CMD_MMC=y
+CONFIG_CMD_POWEROFF=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_USB_MASS_STORAGE=y
+CONFIG_CMD_UMS_ABORT_KEYED=y
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_CMD_PAUSE=y
+CONFIG_CMD_REGULATOR=y
+CONFIG_CMD_EXT4_WRITE=y
+# CONFIG_SPL_DOS_PARTITION is not set
+# CONFIG_SPL_EFI_PARTITION is not set
+CONFIG_ENV_OVERWRITE=y
+CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_SYS_MMC_ENV_PART=2
+CONFIG_BUTTON=y
+CONFIG_USB_FUNCTION_FASTBOOT=y
+CONFIG_FASTBOOT_BUF_ADDR=0x91000000
+CONFIG_FASTBOOT_BUF_SIZE=0x10000000
+CONFIG_FASTBOOT_FLASH=y
+CONFIG_FASTBOOT_FLASH_MMC_DEV=0
+CONFIG_FASTBOOT_CMD_OEM_FORMAT=y
+CONFIG_MAX77663_GPIO=y
+CONFIG_SYS_I2C_TEGRA=y
+CONFIG_BUTTON_KEYBOARD=y
+CONFIG_DM_PMIC=y
+CONFIG_DM_PMIC_MAX77663=y
+CONFIG_DM_REGULATOR=y
+CONFIG_DM_REGULATOR_MAX77663=y
+CONFIG_DM_REGULATOR_FIXED=y
+CONFIG_PWM_TEGRA=y
+CONFIG_SYS_NS16550=y
+CONFIG_SYSRESET_MAX77663=y
+CONFIG_USB=y
+CONFIG_USB_EHCI_HCD=y
+CONFIG_USB_EHCI_TEGRA=y
+CONFIG_USB_KEYBOARD=y
+CONFIG_USB_GADGET=y
+CONFIG_CI_UDC=y
+CONFIG_VIDEO=y
+# CONFIG_VIDEO_LOGO is not set
+CONFIG_VIDEO_TEGRA20=y

doc/board/index.rst

@@ -58,5 +58,6 @@ Board-specific doc
    ti/index
    toradex/index
    variscite/index
+   wexler/index
    xen/index
    xilinx/index

doc/board/wexler/index.rst

@@ -0,0 +1,9 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+WEXLER
+======
+
+.. toctree::
+   :maxdepth: 2
+
+   qc750

doc/board/wexler/qc750.rst

@@ -0,0 +1,125 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+U-Boot for the WEXLER QC750 tablet
+==================================
+
+``DISCLAMER!`` Moving your WEXLER QC750 to use U-Boot assumes replacement
+of the vendor bootloader. Vendor Android firmwares will no longer be able
+to run on the device. This replacement IS reversible.
+
+Quick Start
+-----------
+
+- Build U-Boot
+- Process U-Boot
+- Flashing U-Boot into the eMMC
+- Boot
+- Self Upgrading
+
+Build U-Boot
+------------
+
+.. code-block:: bash
+
+    $ export CROSS_COMPILE=arm-linux-gnueabi-
+    $ make qc750_defconfig
+    $ make
+
+After the build succeeds, you will obtain the final ``u-boot-dtb-tegra.bin``
+image, ready for further processing.
+
+Process U-Boot
+--------------
+
+``DISCLAMER!`` All questions related to the re-crypt work should be asked
+in re-crypt repo issues. NOT HERE!
+
+re-crypt is a tool that processes the ``u-boot-dtb-tegra.bin`` binary into form
+usable by device. This process is required only on the first installation or
+to recover the device in case of a failed update.
+
+Permanent installation can be performed either by using the tegrarcm or by
+pre-loading just built U-Boot into RAM.
+
+Processing for the NV3P protocol
+********************************
+
+.. code-block:: bash
+
+    $ git clone https://gitlab.com/grate-driver/re-crypt.git
+    $ cd re-crypt # place your u-boot-dtb-tegra.bin here
+    $ ./re-crypt.py --dev qc750
+
+The script will produce a ``repart-block.bin`` ready to flash.
+
+Processing for pre-loaded U-Boot
+********************************
+
+The procedure is the same, but the ``--split`` argument is used with the
+``re-crypt.py``. The script will produce ``bct.img`` and ``ebt.img`` ready
+to flash.
+
+Flashing U-Boot into the eMMC
+-----------------------------
+
+``DISCLAMER!`` All questions related to tegrarcm should be asked in the proper
+place. NOT HERE! Flashing U-Boot will erase all eMMC, so make a backup before!
+
+Permanent installation can be performed either by using the nv3p protocol or by
+pre-loading just built U-Boot into RAM.
+
+Flashing with the NV3P protocol
+*******************************
+
+Nv3p is a custom Nvidia protocol used to recover bricked devices. Devices can
+enter it either by using ``wheelie`` with the correct ``blob.bin`` file or by
+pre-loading vendor bootloader with the Fusée Gelée.
+
+With nv3p, ``repart-block.bin`` is used. It contains BCT and a bootloader in
+encrypted state in form, which can just be written RAW at the start of eMMC.
+
+.. code-block:: bash
+
+    $ wheelie --bct qc750.bct --bl bootloader.bin
+    $ nvflash --resume --rawdevicewrite 0 1024 repart-block.bin
+
+When flashing is done, reboot the device.
+
+Flashing with a pre-loaded U-Boot
+*********************************
+
+U-Boot pre-loaded into RAM acts the same as when it was booted "cold". Currently
+U-Boot supports bootmenu entry fastboot, which allows to write a processed copy
+of U-Boot permanently into eMMC.
+
+While pre-loading U-Boot, hold the ``volume down`` button which will trigger
+the bootmenu. There, select ``fastboot`` using the volume and power buttons.
+After, on host PC, do:
+
+.. code-block:: bash
+
+    $ fastboot flash 0.1 bct.img
+    $ fastboot flash 0.2 ebt.img
+    $ fastboot reboot
+
+Device will reboot.
+
+Boot
+----
+
+To boot Linux, U-Boot will look for an ``extlinux.conf`` on MicroSD and then on
+eMMC. Additionally, if the Volume Down button is pressed while booting, the
+device will enter bootmenu. Bootmenu contains entries to mount MicroSD and eMMC
+as mass storage, fastboot, reboot, reboot RCM, poweroff, enter U-Boot console
+and update bootloader (check the next chapter).
+
+Flashing ``repart-block.bin`` eliminates vendor restrictions on eMMC and allows
+the user to use/partition it in any way the user desires.
+
+Self Upgrading
+--------------
+
+Place your ``u-boot-dtb-tegra.bin`` on the first partition of the MicroSD card
+and insert it into the tablet. Enter bootmenu, choose update the bootloader
+option with the Power button and U-Boot should update itself. Once the process
+is completed, U-Boot will ask to press any button to reboot.

include/configs/qc750.h

@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  (C) Copyright 2010,2012
+ *  NVIDIA Corporation <www.nvidia.com>
+ *
+ *  (C) Copyright 2023
+ *  Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#ifndef __CONFIG_H
+#define __CONFIG_H
+
+#include "tegra30-common.h"
+
+/* High-level configuration options */
+#define CFG_TEGRA_BOARD_STRING		"Wexler QC750"
+
+#define QC750_FLASH_UBOOT \
+	"flash_uboot=echo Preparing RAM;" \
+		"mw ${kernel_addr_r} 0 ${boot_block_size_r};" \
+		"mw ${ramdisk_addr_r} 0 ${boot_block_size_r};" \
+		"echo Reading BCT;" \
+		"mmc dev 0 1;" \
+		"mmc read ${kernel_addr_r} 0 ${boot_block_size};" \
+		"echo Reading bootloader;" \
+		"if load mmc 1:1 ${ramdisk_addr_r} ${bootloader_file};" \
+		"then echo Calculating bootloader size;" \
+			"size mmc 1:1 ${bootloader_file};" \
+			"ebtupdate ${kernel_addr_r} ${ramdisk_addr_r} ${filesize};" \
+			"echo Writing bootloader to eMMC;" \
+			"mmc dev 0 1;" \
+			"mmc write ${kernel_addr_r} 0 ${boot_block_size};" \
+			"mmc dev 0 2;" \
+			"mmc write ${ramdisk_addr_r} 0 ${boot_block_size};" \
+			"echo Bootloader written successfully;" \
+			"pause 'Press ANY key to reboot device...'; reset;" \
+		"else echo Reading bootloader failed;" \
+			"pause 'Press ANY key to return to bootmenu...'; bootmenu; fi\0"
+
+#define QC750_BOOTMENU \
+	QC750_FLASH_UBOOT \
+	"bootmenu_0=mount internal storage=usb start && ums 0 mmc 0; bootmenu\0" \
+	"bootmenu_1=mount external storage=usb start && ums 0 mmc 1; bootmenu\0" \
+	"bootmenu_2=fastboot=echo Starting Fastboot protocol ...; fastboot usb 0; bootmenu\0" \
+	"bootmenu_3=update bootloader=run flash_uboot\0" \
+	"bootmenu_4=reboot RCM=enterrcm\0" \
+	"bootmenu_5=reboot=reset\0" \
+	"bootmenu_6=power off=poweroff\0" \
+	"bootmenu_delay=-1\0"
+
+#define BOARD_EXTRA_ENV_SETTINGS \
+	"boot_block_size_r=0x200000\0" \
+	"boot_block_size=0x1000\0" \
+	"bootloader_file=u-boot-dtb-tegra.bin\0" \
+	"button_cmd_0_name=Volume Down\0" \
+	"button_cmd_0=bootmenu\0" \
+	"partitions=name=emmc,start=0,size=-,uuid=${uuid_gpt_rootfs}\0" \
+	QC750_BOOTMENU
+
+/* Board-specific serial config */
+#define CFG_SYS_NS16550_COM1		NV_PA_APB_UARTD_BASE
+
+#include "tegra-common-post.h"
+
+#endif /* __CONFIG_H */