--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0+:
+
+dm command
+==========
+
+Synopis
+-------
+
+::
+
+ dm compat
+ dm devres
+ dm drivers
+ dm static
+ dm tree
+ dm uclass
+
+Description
+-----------
+
+The *dm* command allows viewing information about driver model, including the
+tree of devices and list of available uclasses.
+
+
+dm compat
+~~~~~~~~~
+
+This shows the compatible strings associated with each driver. Often there
+is only one, but multiple strings are shown on their own line. These strings
+can be looked up in the device tree files for each board, to see which driver is
+used for each node.
+
+dm devres
+~~~~~~~~~
+
+This shows a list of a `devres` (device resource) records for a device. Some
+drivers use the devres API to allocate memory, so that it can be freed
+automatically (without any code needed in the driver's remove() method) when the
+device is removed.
+
+This feature is controlled by CONFIG_DEVRES so no useful output is obtained if
+this option is disabled.
+
+dm drivers
+~~~~~~~~~~
+
+This shows all the available drivers, their uclass and a list of devices that
+use that driver, each on its own line. Drivers with no devices are shown with
+`<none>` as the driver name.
+
+
+dm mem
+~~~~~~
+
+This subcommand is really just for debugging and exploration. It can be enabled
+with the `CONFIG_DM_STATS` option.
+
+All output is in hex except that in brackets which is decimal.
+
+The output consists of a header shows the size of the main device model
+structures (struct udevice, struct driver, struct uclass and struct uc_driver)
+and the count and memory used by each (number of devices, memory used by
+devices, memory used by device names, number of uclasses, memory used by
+uclasses).
+
+After that is a table of information about each type of data that can be
+attached to a device, showing the number that have non-null data for that type,
+the total size of all that data, the amount of memory used in total, the
+amount that would be used if this type uses tags instead and the amount that
+would be thus saved.
+
+The `driver_data` line shows the number of devices which have non-NULL driver
+data.
+
+The `tags` line shows the number of tags and the memory used by those.
+
+At the bottom is an indication of the total memory usage obtained by undertaking
+various changes, none of which is currently implemented in U-Boot:
+
+With tags
+ Using tags instead of all attached types
+
+Singly linked
+ Using a singly linked list
+
+driver index
+ Using a driver index instead of a pointer
+
+uclass index
+ Using a uclass index instead of a pointer
+
+Drop device name
+ Using empty device names
+
+
+dm static
+~~~~~~~~~
+
+This shows devices bound by platform data, i.e. not from the device tree. There
+are normally none of these, but some boards may use static devices for space
+reasons.
+
+
+dm tree
+~~~~~~~
+
+This shows the full tree of devices including the following fields:
+
+uclass
+ Shows the name of the uclass for the device
+
+Index
+ Shows the index number of the device, within the uclass. This shows the
+ ordering within the uclass, but not the sequence number.
+
+Probed
+ Shows `+` if the device is active
+
+Driver
+ Shows the name of the driver that this device uses
+
+Name
+ Shows the device name as well as the tree structure, since child devices are
+ shown attached to their parent.
+
+
+dm uclass
+~~~~~~~~~
+
+This shows each uclass along with a list of devices in that uclass. The uclass
+ID is shown (e.g. uclass 7) and its name.
+
+For each device, the format is::
+
+ n name @ a, seq s
+
+where `n` is the index within the uclass, `a` is the address of the device in
+memory and `s` is the sequence number of the device.
+
+
+Examples
+--------
+
+dm compat
+~~~~~~~~~
+
+This example shows an abridged version of the sandbox output::
+
+ => dm compat
+ Driver Compatible
+ --------------------------------
+ act8846_reg
+ sandbox_adder sandbox,adder
+ axi_sandbox_bus sandbox,axi
+ blk_partition
+ bootcount-rtc u-boot,bootcount-rtc
+ ...
+ rockchip_rk805 rockchip,rk805
+ rockchip,rk808
+ rockchip,rk809
+ rockchip,rk816
+ rockchip,rk817
+ rockchip,rk818
+ root_driver
+ rtc-rv8803 microcrystal,rv8803
+ epson,rx8803
+ epson,rx8900
+ ...
+ wdt_gpio linux,wdt-gpio
+ wdt_sandbox sandbox,wdt
+
+
+dm devres
+~~~~~~~~~
+
+This example shows an abridged version of the sandbox test output (running
+U-Boot with the -T flag)::
+
+ => dm devres
+ - root_driver
+ - demo_shape_drv
+ - demo_simple_drv
+ - demo_shape_drv
+ ...
+ - h-test
+ - devres-test
+ 00000000130194e0 (100 byte) devm_kmalloc_release BIND
+ - another-test
+ ...
+ - syscon@3
+ - a-mux-controller
+ 0000000013025e60 (96 byte) devm_kmalloc_release PROBE
+ 0000000013025f00 (24 byte) devm_kmalloc_release PROBE
+ 0000000013026010 (24 byte) devm_kmalloc_release PROBE
+ 0000000013026070 (24 byte) devm_kmalloc_release PROBE
+ 00000000130260d0 (24 byte) devm_kmalloc_release PROBE
+ - syscon@3
+ - a-mux-controller
+ 0000000013026150 (96 byte) devm_kmalloc_release PROBE
+ 00000000130261f0 (24 byte) devm_kmalloc_release PROBE
+ 0000000013026300 (24 byte) devm_kmalloc_release PROBE
+ 0000000013026360 (24 byte) devm_kmalloc_release PROBE
+ 00000000130263c0 (24 byte) devm_kmalloc_release PROBE
+ - emul-mux-controller
+ 0000000013025fa0 (32 byte) devm_kmalloc_release PROBE
+ - testfdtm0
+ - testfdtm1
+ ...
+ - pinmux_spi0_pins
+ - pinmux_uart0_pins
+ - pinctrl-single-bits
+ 0000000013229180 (320 byte) devm_kmalloc_release PROBE
+ 0000000013229300 (40 byte) devm_kmalloc_release PROBE
+ 0000000013229370 (160 byte) devm_kmalloc_release PROBE
+ 000000001322c190 (40 byte) devm_kmalloc_release PROBE
+ 000000001322c200 (32 byte) devm_kmalloc_release PROBE
+ - pinmux_i2c0_pins
+ ...
+ - reg@0
+ - reg@1
+
+
+dm drivers
+~~~~~~~~~~
+
+This example shows an abridged version of the sandbox output::
+
+ => dm drivers
+ Driver uid uclass Devices
+ ----------------------------------------------------------
+ act8846_reg 087 regulator <none>
+ sandbox_adder 021 axi adder
+ adder
+ axi_sandbox_bus 021 axi axi@0
+ ...
+ da7219 061 misc <none>
+ demo_shape_drv 001 demo demo_shape_drv
+ demo_shape_drv
+ demo_shape_drv
+ demo_simple_drv 001 demo demo_simple_drv
+ demo_simple_drv
+ testfdt_drv 003 testfdt a-test
+ b-test
+ d-test
+ e-test
+ f-test
+ g-test
+ another-test
+ chosen-test
+ testbus_drv 005 testbus some-bus
+ mmio-bus@0
+ mmio-bus@1
+ dsa-port 039 ethernet lan0
+ lan1
+ dsa_sandbox 035 dsa dsa-test
+ eep_sandbox 121 w1_eeprom <none>
+ ...
+ pfuze100_regulator 087 regulator <none>
+ phy_sandbox 077 phy bind-test-child1
+ gen_phy@0
+ gen_phy@1
+ gen_phy@2
+ pinconfig 078 pinconfig gpios
+ gpio0
+ gpio1
+ gpio2
+ gpio3
+ i2c
+ groups
+ pins
+ i2s
+ spi
+ cs
+ pinmux_pwm_pins
+ pinmux_spi0_pins
+ pinmux_uart0_pins
+ pinmux_i2c0_pins
+ pinmux_lcd_pins
+ pmc_sandbox 017 power-mgr pci@1e,0
+ act8846 pmic 080 pmic <none>
+ max77686_pmic 080 pmic <none>
+ mc34708_pmic 080 pmic pmic@41
+ ...
+ wdt_gpio 122 watchdog gpio-wdt
+ wdt_sandbox 122 watchdog wdt@0
+ =>
+
+
+dm mem
+~~~~~~
+
+This example shows the sandbox output::
+
+ > dm mem
+ Struct sizes: udevice b0, driver 80, uclass 30, uc_driver 78
+ Memory: device fe:aea0, device names a16, uclass 5e:11a0
+
+ Attached type Count Size Cur Tags Save
+ --------------- ----- ----- ----- ----- -----
+ plat 45 a8f aea0 a7c4 6dc (1756)
+ parent_plat 1a 3b8 aea0 a718 788 (1928)
+ uclass_plat 3d 6b4 aea0 a7a4 6fc (1788)
+ priv 8a 68f3 aea0 a8d8 5c8 (1480)
+ parent_priv 8 38a0 aea0 a6d0 7d0 (2000)
+ uclass_priv 4e 14a6 aea0 a7e8 6b8 (1720)
+ driver_data f 0 aea0 a6ec 7b4 (1972)
+ uclass 6 20
+ Attached total 191 cb54 3164 (12644)
+ tags 0 0
+
+ Total size: 18b94 (101268)
+
+ With tags: 15a30 (88624)
+ - singly-linked: 14260 (82528)
+ - driver index: 13b6e (80750)
+ - uclass index: 1347c (78972)
+ Drop device name (not SRAM): a16 (2582)
+ =>
+
+
+dm static
+~~~~~~~~~
+
+This example shows the sandbox output::
+
+ => dm static
+ Driver Address
+ ---------------------------------
+ demo_shape_drv 0000562edab8dca0
+ demo_simple_drv 0000562edab8dca0
+ demo_shape_drv 0000562edab8dc90
+ demo_simple_drv 0000562edab8dc80
+ demo_shape_drv 0000562edab8dc80
+ test_drv 0000562edaae8840
+ test_drv 0000562edaae8848
+ test_drv 0000562edaae8850
+ sandbox_gpio 0000000000000000
+ mod_exp_sw 0000000000000000
+ sandbox_test_proc 0000562edabb5330
+ qfw_sandbox 0000000000000000
+ sandbox_timer 0000000000000000
+ sandbox_serial 0000562edaa8ed00
+ sysreset_sandbox 0000000000000000
+
+
+dm tree
+-------
+
+This example shows the abridged sandbox output::
+
+ => dm tree
+ Class Index Probed Driver Name
+ -----------------------------------------------------------
+ root 0 [ + ] root_driver root_driver
+ demo 0 [ ] demo_shape_drv |-- demo_shape_drv
+ demo 1 [ ] demo_simple_drv |-- demo_simple_drv
+ demo 2 [ ] demo_shape_drv |-- demo_shape_drv
+ demo 3 [ ] demo_simple_drv |-- demo_simple_drv
+ demo 4 [ ] demo_shape_drv |-- demo_shape_drv
+ test 0 [ ] test_drv |-- test_drv
+ test 1 [ ] test_drv |-- test_drv
+ test 2 [ ] test_drv |-- test_drv
+ ..
+ sysreset 0 [ ] sysreset_sandbox |-- sysreset_sandbox
+ bootstd 0 [ ] bootstd_drv |-- bootstd
+ bootmeth 0 [ ] bootmeth_distro | |-- syslinux
+ bootmeth 1 [ ] bootmeth_efi | `-- efi
+ reboot-mod 0 [ ] reboot-mode-gpio |-- reboot-mode0
+ reboot-mod 1 [ ] reboot-mode-rtc |-- reboot-mode@14
+ ...
+ ethernet 7 [ + ] dsa-port | `-- lan1
+ pinctrl 0 [ + ] sandbox_pinctrl_gpio |-- pinctrl-gpio
+ gpio 1 [ + ] sandbox_gpio | |-- base-gpios
+ nop 0 [ + ] gpio_hog | | |-- hog_input_active_low
+ nop 1 [ + ] gpio_hog | | |-- hog_input_active_high
+ nop 2 [ + ] gpio_hog | | |-- hog_output_low
+ nop 3 [ + ] gpio_hog | | `-- hog_output_high
+ gpio 2 [ ] sandbox_gpio | |-- extra-gpios
+ gpio 3 [ ] sandbox_gpio | `-- pinmux-gpios
+ i2c 0 [ + ] sandbox_i2c |-- i2c@0
+ i2c_eeprom 0 [ ] i2c_eeprom | |-- eeprom@2c
+ i2c_eeprom 1 [ ] i2c_eeprom_partition | | `-- bootcount@10
+ rtc 0 [ ] sandbox_rtc | |-- rtc@43
+ rtc 1 [ + ] sandbox_rtc | |-- rtc@61
+ i2c_emul_p 0 [ + ] sandbox_i2c_emul_par | |-- emul
+ i2c_emul 0 [ ] sandbox_i2c_eeprom_e | | |-- emul-eeprom
+ i2c_emul 1 [ ] sandbox_i2c_rtc_emul | | |-- emul0
+ i2c_emul 2 [ + ] sandbox_i2c_rtc_emul | | |-- emull
+ i2c_emul 3 [ ] sandbox_i2c_pmic_emu | | |-- pmic-emul0
+ i2c_emul 4 [ ] sandbox_i2c_pmic_emu | | `-- pmic-emul1
+ pmic 0 [ ] sandbox_pmic | |-- sandbox_pmic
+ regulator 0 [ ] sandbox_buck | | |-- buck1
+ regulator 1 [ ] sandbox_buck | | |-- buck2
+ regulator 2 [ ] sandbox_ldo | | |-- ldo1
+ regulator 3 [ ] sandbox_ldo | | |-- ldo2
+ regulator 4 [ ] sandbox_buck | | `-- no_match_by_nodename
+ pmic 1 [ ] mc34708_pmic | `-- pmic@41
+ bootcount 0 [ + ] bootcount-rtc |-- bootcount@0
+ bootcount 1 [ ] bootcount-i2c-eeprom |-- bootcount
+ ...
+ clk 4 [ ] fixed_clock |-- osc
+ firmware 0 [ ] sandbox_firmware |-- sandbox-firmware
+ scmi_agent 0 [ ] sandbox-scmi_agent `-- scmi
+ clk 5 [ ] scmi_clk |-- protocol@14
+ reset 2 [ ] scmi_reset_domain |-- protocol@16
+ nop 8 [ ] scmi_voltage_domain `-- regulators
+ regulator 5 [ ] scmi_regulator |-- reg@0
+ regulator 6 [ ] scmi_regulator `-- reg@1
+ =>
+
+
+dm uclass
+~~~~~~~~~
+
+This example shows the abridged sandbox output::
+
+ => dm uclass
+ uclass 0: root
+ 0 * root_driver @ 03015460, seq 0
+
+ uclass 1: demo
+ 0 demo_shape_drv @ 03015560, seq 0
+ 1 demo_simple_drv @ 03015620, seq 1
+ 2 demo_shape_drv @ 030156e0, seq 2
+ 3 demo_simple_drv @ 030157a0, seq 3
+ 4 demo_shape_drv @ 03015860, seq 4
+
+ uclass 2: test
+ 0 test_drv @ 03015980, seq 0
+ 1 test_drv @ 03015a60, seq 1
+ 2 test_drv @ 03015b40, seq 2
+ ...
+ uclass 20: audio-codec
+ 0 audio-codec @ 030168e0, seq 0
+
+ uclass 21: axi
+ 0 adder @ 0301db60, seq 1
+ 1 adder @ 0301dc40, seq 2
+ 2 axi@0 @ 030217d0, seq 0
+
+ uclass 22: blk
+ 0 mmc2.blk @ 0301ca00, seq 0
+ 1 mmc1.blk @ 0301cee0, seq 1
+ 2 mmc0.blk @ 0301d380, seq 2
+
+ uclass 23: bootcount
+ 0 * bootcount@0 @ 0301b3f0, seq 0
+ 1 bootcount @ 0301b4b0, seq 1
+ 2 bootcount_4@0 @ 0301b570, seq 2
+ 3 bootcount_2@0 @ 0301b630, seq 3
+
+ uclass 24: bootdev
+ 0 mmc2.bootdev @ 0301cbb0, seq 0
+ 1 mmc1.bootdev @ 0301d050, seq 1
+ 2 mmc0.bootdev @ 0301d4f0, seq 2
+
+ ...
+ uclass 78: pinconfig
+ 0 gpios @ 03022410, seq 0
+ 1 gpio0 @ 030224d0, seq 1
+ 2 gpio1 @ 03022590, seq 2
+ 3 gpio2 @ 03022650, seq 3
+ 4 gpio3 @ 03022710, seq 4
+ 5 i2c @ 030227d0, seq 5
+ 6 groups @ 03022890, seq 6
+ 7 pins @ 03022950, seq 7
+ 8 i2s @ 03022a10, seq 8
+ 9 spi @ 03022ad0, seq 9
+ 10 cs @ 03022b90, seq 10
+ 11 pinmux_pwm_pins @ 03022e10, seq 11
+ 12 pinmux_spi0_pins @ 03022ed0, seq 12
+ 13 pinmux_uart0_pins @ 03022f90, seq 13
+ 14 * pinmux_i2c0_pins @ 03023130, seq 14
+ 15 * pinmux_lcd_pins @ 030231f0, seq 15
+
+ ...
+ uclass 119: virtio
+ 0 sandbox_virtio1 @ 030220d0, seq 0
+ 1 sandbox_virtio2 @ 03022190, seq 1
+
+ uclass 120: w1
+ uclass 121: w1_eeprom
+ uclass 122: watchdog
+ 0 * gpio-wdt @ 0301c070, seq 0
+ 1 * wdt@0 @ 03021710, seq 1
+
+ =>