Build U-Boot sandbox and run it:
- make sandbox_config
+ make sandbox_defconfig
make
- ./u-boot
+ ./u-boot -d u-boot.dtb
(type 'reset' to exit U-Boot)
in sandbox, and every uclass has its own test. As a move towards this, tests
are provided in test/dm. To run them, try:
- ./test/dm/test-dm.sh
+ ./test/py/test.py --bd sandbox --build -k ut_dm -v
You should see something like this:
- <...U-Boot banner...>
- Running 29 driver model tests
- Test: dm_test_autobind
- Test: dm_test_autoprobe
- Test: dm_test_bus_children
- Device 'd-test': seq 3 is in use by 'b-test'
- Device 'c-test@0': seq 0 is in use by 'a-test'
- Device 'c-test@1': seq 1 is in use by 'd-test'
- Test: dm_test_bus_children_funcs
- Test: dm_test_bus_children_iterators
- Test: dm_test_bus_parent_data
- Test: dm_test_bus_parent_ops
- Test: dm_test_children
- Test: dm_test_fdt
- Device 'd-test': seq 3 is in use by 'b-test'
- Test: dm_test_fdt_offset
- Test: dm_test_fdt_pre_reloc
- Test: dm_test_fdt_uclass_seq
- Device 'd-test': seq 3 is in use by 'b-test'
- Device 'a-test': seq 0 is in use by 'd-test'
- Test: dm_test_gpio
- extra-gpios: get_value: error: gpio b5 not reserved
- Test: dm_test_gpio_anon
- Test: dm_test_gpio_copy
- Test: dm_test_gpio_leak
- extra-gpios: get_value: error: gpio b5 not reserved
- Test: dm_test_gpio_requestf
- Test: dm_test_leak
- Test: dm_test_lifecycle
- Test: dm_test_operations
- Test: dm_test_ordering
- Test: dm_test_platdata
- Test: dm_test_pre_reloc
- Test: dm_test_remove
- Test: dm_test_spi_find
- Invalid chip select 0:0 (err=-19)
- SF: Failed to get idcodes
- Device 'name-emul': seq 0 is in use by 'name-emul'
- SF: Detected M25P16 with page size 256 Bytes, erase size 64 KiB, total 2 MiB
- Test: dm_test_spi_flash
- 2097152 bytes written in 0 ms
- SF: Detected M25P16 with page size 256 Bytes, erase size 64 KiB, total 2 MiB
- SPI flash test:
- 0 erase: 0 ticks, 65536000 KiB/s 524288.000 Mbps
- 1 check: 0 ticks, 65536000 KiB/s 524288.000 Mbps
- 2 write: 0 ticks, 65536000 KiB/s 524288.000 Mbps
- 3 read: 0 ticks, 65536000 KiB/s 524288.000 Mbps
- Test passed
- 0 erase: 0 ticks, 65536000 KiB/s 524288.000 Mbps
- 1 check: 0 ticks, 65536000 KiB/s 524288.000 Mbps
- 2 write: 0 ticks, 65536000 KiB/s 524288.000 Mbps
- 3 read: 0 ticks, 65536000 KiB/s 524288.000 Mbps
- Test: dm_test_spi_xfer
- SF: Detected M25P16 with page size 256 Bytes, erase size 64 KiB, total 2 MiB
- Test: dm_test_uclass
- Test: dm_test_uclass_before_ready
- Failures: 0
-
+(venv)$ ./test/py/test.py --bd sandbox --build -k ut_dm -v
++make O=/root/u-boot/build-sandbox -s sandbox_defconfig
++make O=/root/u-boot/build-sandbox -s -j8
+============================= test session starts ==============================
+platform linux2 -- Python 2.7.5, pytest-2.9.0, py-1.4.31, pluggy-0.3.1 -- /root/u-boot/venv/bin/python
+cachedir: .cache
+rootdir: /root/u-boot, inifile:
+collected 199 items
+
+test/py/tests/test_ut.py::test_ut_dm_init PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_adc_bind] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_adc_multi_channel_conversion] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_adc_multi_channel_shot] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_adc_single_channel_conversion] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_adc_single_channel_shot] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_adc_supply] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_adc_wrong_channel_selection] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_autobind] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_autobind_uclass_pdata_alloc] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_autobind_uclass_pdata_valid] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_autoprobe] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_child_post_bind] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_child_post_bind_uclass] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_child_pre_probe_uclass] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_children] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_children_funcs] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_children_iterators] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_parent_data] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_parent_data_uclass] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_parent_ops] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_parent_platdata] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_bus_parent_platdata_uclass] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_children] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_clk_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_clk_periph] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_device_get_uclass_id] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_eth] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_eth_act] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_eth_alias] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_eth_prime] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_eth_rotate] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_fdt] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_fdt_offset] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_fdt_pre_reloc] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_fdt_uclass_seq] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_gpio] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_gpio_anon] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_gpio_copy] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_gpio_leak] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_gpio_phandles] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_gpio_requestf] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_i2c_bytewise] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_i2c_find] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_i2c_offset] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_i2c_offset_len] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_i2c_probe_empty] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_i2c_read_write] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_i2c_speed] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_leak] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_led_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_led_gpio] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_led_label] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_lifecycle] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_mmc_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_net_retry] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_operations] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_ordering] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_pci_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_pci_busnum] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_pci_swapcase] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_platdata] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_pmic_get] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_pmic_io] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_regulator_autoset] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_regulator_autoset_list] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_regulator_get] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_regulator_set_get_current] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_regulator_set_get_enable] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_regulator_set_get_mode] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_power_regulator_set_get_voltage] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_pre_reloc] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_ram_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_regmap_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_regmap_syscon] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_remoteproc_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_remove] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_reset_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_reset_walk] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_rtc_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_rtc_dual] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_rtc_reset] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_rtc_set_get] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_spi_find] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_spi_flash] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_spi_xfer] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_syscon_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_syscon_by_driver_data] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_timer_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_uclass] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_uclass_before_ready] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_uclass_devices_find] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_uclass_devices_find_by_name] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_uclass_devices_get] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_uclass_devices_get_by_name] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_usb_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_usb_flash] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_usb_keyb] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_usb_multi] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_usb_remove] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_usb_tree] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_usb_tree_remove] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_usb_tree_reorder] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_base] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_bmp] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_bmp_comp] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_chars] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_context] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_rotation1] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_rotation2] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_rotation3] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_text] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_truetype] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_truetype_bs] PASSED
+test/py/tests/test_ut.py::test_ut[ut_dm_video_truetype_scroll] PASSED
+
+======================= 84 tests deselected by '-kut_dm' =======================
+================== 115 passed, 84 deselected in 3.77 seconds ===================
What is going on?
-----------------
Platform Data
-------------
+*** Note: platform data is the old way of doing things. It is
+*** basically a C structure which is passed to drivers to tell them about
+*** platform-specific settings like the address of its registers, bus
+*** speed, etc. Device tree is now the preferred way of handling this.
+*** Unless you have a good reason not to use device tree (the main one
+*** being you need serial support in SPL and don't have enough SRAM for
+*** the cut-down device tree and libfdt libraries) you should stay away
+*** from platform data.
+
Platform data is like Linux platform data, if you are familiar with that.
It provides the board-specific information to start up a device.
-----------
While platdata is useful, a more flexible way of providing device data is
-by using device tree. With device tree we replace the above code with the
-following device tree fragment:
+by using device tree. In U-Boot you should use this where possible. Avoid
+sending patches which make use of the U_BOOT_DEVICE() macro unless strictly
+necessary.
+
+With device tree we replace the above code with the following device tree
+fragment:
red-square {
compatible = "demo-shape";
in your ofdata_to_platdata (or probe) method to allocate the required memory,
and you should free it in the remove method.
+The driver model tree is intended to mirror that of the device tree. The
+root driver is at device tree offset 0 (the root node, '/'), and its
+children are the children of the root node.
+
Declaring Uclasses
------------------
U-Boot numbers devices from 0 in many situations, such as in the command
line for I2C and SPI buses, and the device names for serial ports (serial0,
serial1, ...). Driver model supports this numbering and permits devices
-to be locating by their 'sequence'. This numbering unique identifies a
+to be locating by their 'sequence'. This numbering uniquely identifies a
device in its uclass, so no two devices within a particular uclass can have
the same sequence number.
Sequence numbers start from 0 but gaps are permitted. For example, a board
-may have I2C buses 0, 1, 4, 5 but no 2 or 3. The choice of how devices are
+may have I2C buses 1, 4, 5 but no 0, 2 or 3. The choice of how devices are
numbered is up to a particular board, and may be set by the SoC in some
cases. While it might be tempting to automatically renumber the devices
where there are gaps in the sequence, this can lead to confusion and is
device will be automatically allocated the next available sequence number.
To specify the sequence number in the device tree an alias is typically
-used.
+used. Make sure that the uclass has the DM_UC_FLAG_SEQ_ALIAS flag set.
aliases {
serial2 = "/serial@22230000";
("/serial@22230000") will be given sequence number 2. Any command or driver
which requests serial device 2 will obtain this device.
-Some devices represent buses where the devices on the bus are numbered or
-addressed. For example, SPI typically numbers its slaves from 0, and I2C
-uses a 7-bit address. In these cases the 'reg' property of the subnode is
-used, for example:
-
-{
- aliases {
- spi2 = "/spi@22300000";
- };
-
- spi@22300000 {
- #address-cells = <1>;
- #size-cells = <1>;
- spi-flash@0 {
- reg = <0>;
- ...
- }
- eeprom@1 {
- reg = <1>;
- };
- };
-
-In this case we have a SPI bus with two slaves at 0 and 1. The SPI bus
-itself is numbered 2. So we might access the SPI flash with:
+More commonly you can use node references, which expand to the full path:
- sf probe 2:0
-
-and the eeprom with
-
- sspi 2:1 32 ef
-
-These commands simply need to look up the 2nd device in the SPI uclass to
-find the right SPI bus. Then, they look at the children of that bus for the
-right sequence number (0 or 1 in this case).
+aliases {
+ serial2 = &serial_2;
+};
+...
+serial_2: serial@22230000 {
+...
+};
-Typically the alias method is used for top-level nodes and the 'reg' method
-is used only for buses.
+The alias resolves to the same string in this case, but this version is
+easier to read.
Device sequence numbers are resolved when a device is probed. Before then
the sequence number is only a request which may or may not be honoured,
the bus provides some sort of transport or translation that makes it
possible to talk to the devices on the bus.
-Driver model provides a few useful features to help with implementing
-buses. Firstly, a bus can request that its children store some 'parent
-data' which can be used to keep track of child state. Secondly, the bus can
-define methods which are called when a child is probed or removed. This is
-similar to the methods the uclass driver provides.
+Driver model provides some useful features to help with implementing buses.
+Firstly, a bus can request that its children store some 'parent data' which
+can be used to keep track of child state. Secondly, the bus can define
+methods which are called when a child is probed or removed. This is similar
+to the methods the uclass driver provides. Thirdly, per-child platform data
+can be provided to specify things like the child's address on the bus. This
+persists across child probe()/remove() cycles.
+
+For consistency and ease of implementation, the bus uclass can specify the
+per-child platform data, so that it can be the same for all children of buses
+in that uclass. There are also uclass methods which can be called when
+children are bound and probed.
Here an explanation of how a bus fits with a uclass may be useful. Consider
a USB bus with several devices attached to it, each from a different (made
The bus device wants to store this address and some other information such
as the bus speed for each device.
-To achieve this, the bus device can use dev->parent_priv in each of its
-three children. This can be auto-allocated if the bus driver has a non-zero
-value for per_child_auto_alloc_size. If not, then the bus device can
-allocate the space itself before the child device is probed.
+To achieve this, the bus device can use dev->parent_platdata in each of its
+three children. This can be auto-allocated if the bus driver (or bus uclass)
+has a non-zero value for per_child_platdata_auto_alloc_size. If not, then
+the bus device or uclass can allocate the space itself before the child
+device is probed.
Also the bus driver can define the child_pre_probe() and child_post_remove()
methods to allow it to do some processing before the child is activated or
after it is deactivated.
+Similarly the bus uclass can define the child_post_bind() method to obtain
+the per-child platform data from the device tree and set it up for the child.
+The bus uclass can also provide a child_pre_probe() method. Very often it is
+the bus uclass that controls these features, since it avoids each driver
+having to do the same processing. Of course the driver can still tweak and
+override these activities.
+
Note that the information that controls this behaviour is in the bus's
driver, not the child's. In fact it is possible that child has no knowledge
that it is connected to a bus. The same child device may even be used on two
The uclass for the device can also contain data private to that uclass.
But note that each device on the bus may be a memeber of a different
uclass, and this data has nothing to do with the child data for each child
-on the bus.
+on the bus. It is the bus' uclass that controls the child with respect to
+the bus.
Driver Lifecycle
1. Bind stage
-A device and its driver are bound using one of these two methods:
+U-Boot discovers devices using one of these two methods:
- - Scan the U_BOOT_DEVICE() definitions. U-Boot It looks up the
-name specified by each, to find the appropriate driver. It then calls
-device_bind() to create a new device and bind' it to its driver. This will
-call the device's bind() method.
+ - Scan the U_BOOT_DEVICE() definitions. U-Boot looks up the name specified
+by each, to find the appropriate U_BOOT_DRIVER() definition. In this case,
+there is no path by which driver_data may be provided, but the U_BOOT_DEVICE()
+may provide platdata.
- Scan through the device tree definitions. U-Boot looks at top-level
nodes in the the device tree. It looks at the compatible string in each node
-and uses the of_match part of the U_BOOT_DRIVER() structure to find the
-right driver for each node. It then calls device_bind() to bind the
-newly-created device to its driver (thereby creating a device structure).
-This will also call the device's bind() method.
+and uses the of_match table of the U_BOOT_DRIVER() structure to find the
+right driver for each node. In this case, the of_match table may provide a
+driver_data value, but platdata cannot be provided until later.
+
+For each device that is discovered, U-Boot then calls device_bind() to create a
+new device, initializes various core fields of the device object such as name,
+uclass & driver, initializes any optional fields of the device object that are
+applicable such as of_offset, driver_data & platdata, and finally calls the
+driver's bind() method if one is defined.
At this point all the devices are known, and bound to their drivers. There
is a 'struct udevice' allocated for all devices. However, nothing has been
g. If the driver provides an ofdata_to_platdata() method, then this is
called to convert the device tree data into platform data. This should
- do various calls like fdtdec_get_int(gd->fdt_blob, dev->of_offset, ...)
+ do various calls like fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), ...)
to access the node and store the resulting information into dev->platdata.
After this point, the device works the same way whether it was bound
using a device tree node or U_BOOT_DEVICE() structure. In either case,
'u-boot,dm-pre-reloc' flag are initialised prior to relocation. This helps
to reduce the driver model overhead.
+It is possible to limit this to specific relocation steps, by using
+the more specialized 'u-boot,dm-spl' and 'u-boot,dm-tpl' flags
+in the devicetree.
+
Then post relocation we throw that away and re-init driver model again.
For drivers which require some sort of continuity between pre- and
post-relocation devices, we can provide access to the pre-relocation
projects / u-boot / blobdiff