mirror of
https://github.com/smaeul/u-boot.git
synced 2025-11-17 09:18:53 +00:00
3d1957f0ea
Add a new I2C_MUX uclass. Devices in this class can multiplex between several I2C buses, selecting them one at a time for use by the system. The multiplexing mechanism is left to the driver to decide - it may be controlled by GPIOs, for example. The uclass supports only two methods: select() and deselect(). The current mux state is expected to be stored in the mux itself since it is the only thing that knows how to make things work. The mux can record the current state and then avoid switching unless it is necessary. So select() can be skipped if the mux is already in the correct state. Also deselect() can be made a nop if required. Signed-off-by: Simon Glass <sjg@chromium.org>
# # Xilinx ZYNQ U-Boot # # (C) Copyright 2013 Xilinx, Inc. # # SPDX-License-Identifier: GPL-2.0+ # 1. About this This document describes the information about Xilinx Zynq U-Boot - like supported boards, ML status and TODO list. 2. Zynq boards Xilinx Zynq-7000 All Programmable SoCs enable extensive system level differentiation, integration, and flexibility through hardware, software, and I/O programmability. * zc702 (single qspi, gem0, mmc) [1] * zc706 (dual parallel qspi, gem0, mmc) [2] * zed (single qspi, gem0, mmc) [3] * microzed (single qspi, gem0, mmc) [4] * zc770 - zc770-xm010 (single qspi, gem0, mmc) - zc770-xm011 (8 or 16 bit nand) - zc770-xm012 (nor) - zc770-xm013 (dual parallel qspi, gem1) 3. Building ex. configure and build for zc702 board $ make zynq_zc702_config $ make 4. Bootmode Zynq has a facility to read the bootmode from the slcr bootmode register once user is setting through jumpers on the board - see page no:1546 on [5] All possible bootmode values are defined in Table 6-2:Boot_Mode MIO Pins on [5]. board_late_init() will read the bootmode values using slcr bootmode register at runtime and assign the modeboot variable to specific bootmode string which is intern used in autoboot. SLCR bootmode register Bit[3:0] values #define ZYNQ_BM_NOR 0x02 #define ZYNQ_BM_SD 0x05 #define ZYNQ_BM_JTAG 0x0 "modeboot" variable can assign any of "norboot", "sdboot" or "jtagboot" bootmode strings at runtime. 5. Mainline status - Added basic board configurations support. - Added zynq u-boot bsp code - arch/arm/cpu/armv7/zynq - Added zynq boards named - zc70x, zed, microzed, zc770_xm010, zc770_xm012, zc770_xm013 - Added zynq drivers: serial - drivers/serial/serial_zynq.c net - drivers/net/zynq_gem.c mmc - drivers/mmc/zynq_sdhci.c mmc - drivers/mmc/zynq_sdhci.c spi- drivers/spi/zynq_spi.c i2c - drivers/i2c/zynq_i2c.c - Done proper cleanups on board configurations - Added basic FDT support for zynq boards - d-cache support for zynq_gem.c 6. TODO - Add zynq boards support - zc770_xm011 - Add zynq qspi controller driver - Add zynq nand controller driver - Add FDT support on individual drivers [1] http://www.xilinx.com/products/boards-and-kits/EK-Z7-ZC702-G.htm [2] http://www.xilinx.com/products/boards-and-kits/EK-Z7-ZC706-G.htm [3] http://zedboard.org/product/zedboard [4] http://zedboard.org/product/microzed [5] http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf -- Jagannadha Sutradharudu Teki <jaganna@xilinx.com> Sun Dec 15 14:52:41 IST 2013