README: remove description about driver model configuration options (again)

The Driver Model description in README was removed by commit
65eb659e56 (README: remove description about driver model
configuration options), and was revived by mistake by commit
b79dadf846 when resolving the conflict.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Tom Rini <trini@konsulko.com>
Acked-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Masahiro Yamada 2015-03-11 17:34:25 +09:00 committed by Tom Rini
parent 90b7caaf55
commit 3bde6888c0

113
README
View file

@ -705,119 +705,6 @@ The following options need to be configured:
impossible actions will be skipped if the CPU is in NS mode,
such as ARM architectural timer initialization.
- Driver Model
Driver model is a new framework for devices in U-Boot
introduced in early 2014. U-Boot is being progressively
moved over to this. It offers a consistent device structure,
supports grouping devices into classes and has built-in
handling of platform data and device tree.
To enable transition to driver model in a relatively
painful fashion, each subsystem can be independently
switched between the legacy/ad-hoc approach and the new
driver model using the options below. Also, many uclass
interfaces include compatibility features which may be
removed once the conversion of that subsystem is complete.
As a result, the API provided by the subsystem may in fact
not change with driver model.
See doc/driver-model/README.txt for more information.
CONFIG_DM
Enable driver model. This brings in the core support,
including scanning of platform data on start-up. If
CONFIG_OF_CONTROL is enabled, the device tree will be
scanned also when available.
CONFIG_CMD_DM
Enable driver model test commands. These allow you to print
out the driver model tree and the uclasses.
CONFIG_DM_DEMO
Enable some demo devices and the 'demo' command. These are
really only useful for playing around while trying to
understand driver model in sandbox.
CONFIG_SPL_DM
Enable driver model in SPL. You will need to provide a
suitable malloc() implementation. If you are not using the
full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
In most cases driver model will only allocate a few uclasses
and devices in SPL, so 1KB should be enable. See
CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
it.
CONFIG_DM_SERIAL
Enable driver model for serial. This replaces
drivers/serial/serial.c with the serial uclass, which
implements serial_putc() etc. The uclass interface is
defined in include/serial.h.
CONFIG_DM_GPIO
Enable driver model for GPIO access. The standard GPIO
interface (gpio_get_value(), etc.) is then implemented by
the GPIO uclass. Drivers provide methods to query the
particular GPIOs that they provide. The uclass interface
is defined in include/asm-generic/gpio.h.
CONFIG_DM_SPI
Enable driver model for SPI. The SPI slave interface
(spi_setup_slave(), spi_xfer(), etc.) is then implemented by
the SPI uclass. Drivers provide methods to access the SPI
buses that they control. The uclass interface is defined in
include/spi.h. The existing spi_slave structure is attached
as 'parent data' to every slave on each bus. Slaves
typically use driver-private data instead of extending the
spi_slave structure.
CONFIG_DM_SPI_FLASH
Enable driver model for SPI flash. This SPI flash interface
(spi_flash_probe(), spi_flash_write(), etc.) is then
implemented by the SPI flash uclass. There is one standard
SPI flash driver which knows how to probe most chips
supported by U-Boot. The uclass interface is defined in
include/spi_flash.h, but is currently fully compatible
with the old interface to avoid confusion and duplication
during the transition parent. SPI and SPI flash must be
enabled together (it is not possible to use driver model
for one and not the other).
CONFIG_DM_CROS_EC
Enable driver model for the Chrome OS EC interface. This
allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
but otherwise makes few changes. Since cros_ec also supports
I2C and LPC (which don't support driver model yet), a full
conversion is not yet possible.
** Code size options: The following options are enabled by
default except in SPL. Enable them explicitly to get these
features in SPL.
CONFIG_DM_WARN
Enable the dm_warn() function. This can use up quite a bit
of space for its strings.
CONFIG_DM_STDIO
Enable registering a serial device with the stdio library.
CONFIG_DM_DEVICE_REMOVE
Enable removing of devices.
- Linux Kernel Interface:
CONFIG_CLOCKS_IN_MHZ