Add a driver which sets up the pin configuration on x86 devices with an ICH6
(or later) Platform Controller Hub.
The driver is not in the pinctrl uclass due to some oddities of the way x86
devices work:
- The GPIO controller is not present in I/O space until it is set up
- This is done by writing a register in the PCH
- The PCH has a driver which itself uses PCI, another driver
- The pinctrl uclass requires that a pinctrl device be available before any
other device can be probed
It would be possible to work around the limitations by:
- Hard-coding the GPIO address rather than reading it from the PCH
- Using special x86 PCI access to set the GPIO address in the PCH
However it is not clear that this is better, since the pin configuration
driver does not actually provide normal pin configuration services - it
simply sets up all the pins statically when probed. While this remains the
case, it seems better to use a syscon uclass instead. This can be probed
whenever it is needed, without any limitations.
Also add an 'invert' property to support inverting the input.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
#
# 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
7ac99be6e2