-- 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.
-
projects / karo-tx-uboot.git / blobdiff