diff options
Diffstat (limited to 'doc/develop/driver-model/of-plat.rst')
| -rw-r--r-- | doc/develop/driver-model/of-plat.rst | 148 |
1 files changed, 140 insertions, 8 deletions
diff --git a/doc/develop/driver-model/of-plat.rst b/doc/develop/driver-model/of-plat.rst index 8a8eaed4c11..237af38ad4d 100644 --- a/doc/develop/driver-model/of-plat.rst +++ b/doc/develop/driver-model/of-plat.rst @@ -215,16 +215,16 @@ For example: static int mmc_of_to_plat(struct udevice *dev) { - #if !CONFIG_IS_ENABLED(OF_PLATDATA) + if (CONFIG_IS_ENABLED(OF_REAL)) { /* Decode the devicetree data */ struct mmc_plat *plat = dev_get_plat(dev); const void *blob = gd->fdt_blob; int node = dev_of_offset(dev); plat->fifo_depth = fdtdec_get_int(blob, node, "fifo-depth", 0); - #endif + } - return 0; + return 0; } static int mmc_probe(struct udevice *dev) @@ -600,6 +600,11 @@ as a macro included in the driver definition:: Problems -------- +This section shows some common problems and how to fix them. + +Driver not found +~~~~~~~~~~~~~~~~ + In some cases you will you see something like this:: WARNING: the driver rockchip_rk3188_grf was not found in the driver list @@ -633,8 +638,11 @@ the devicetree. For example, if the devicetree has:: then dtoc looks at the first compatible string ("rockchip,rk3188-grf"), converts that to a C identifier (rockchip_rk3188_grf) and then looks for that. +Missing .compatible or Missing .id +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + Various things can cause dtoc to fail to find the driver and it tries to -warn about these. For example: +warn about these. For example:: rockchip_rk3188_uart: Missing .compatible in drivers/serial/serial_rockchip.c : WARNING: the driver rockchip_rk3188_uart was not found in the driver list @@ -649,6 +657,130 @@ Checks are also made to confirm that the referenced driver has a .compatible member and a .id member. The first provides the array of compatible strings and the second provides the uclass ID. +Missing parent +~~~~~~~~~~~~~~ + +When a device is used, its parent must be present as well. If you see an error +like:: + + Node '/i2c@0/emul/emul0' requires parent node '/i2c@0/emul' but it is not in + the valid list + +it indicates that you are using a node whose parent is not present in the +devicetree. In this example, if you look at the device tree output +(e.g. fdtdump tpl/u-boot-tpl.dtb in your build directory), you may see something +like this:: + + emul { + emul0 { + compatible = "sandbox,i2c-rtc-emul"; + #emul-cells = <0x00000000>; + phandle = <0x00000003>; + }; + }; + +In this example, 'emul0' exists but its parent 'emul' has no properties. These +have been dropped by fdtgrep in an effort to reduce the devicetree size. This +indicates that the two nodes have different phase settings. Looking at the +source .dts:: + + i2c_emul: emul { + u-boot,dm-spl; + reg = <0xff>; + compatible = "sandbox,i2c-emul-parent"; + emul0: emul0 { + u-boot,dm-pre-reloc; + compatible = "sandbox,i2c-rtc-emul"; + #emul-cells = <0>; + }; + }; + +you can see that the child node 'emul0' usees 'u-boot,dm-pre-reloc', indicating +that the node is present in all SPL builds, but its parent uses 'u-boot,dm-spl' +indicating it is only present in SPL, not TPL. For a TPL build, this will fail +with the above message. The fix is to change 'emul0' to use the same +'u-boot,dm-spl' condition, so that it is not present in TPL, like its parent. + +Link errors / undefined reference +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Sometimes dtoc does not find the problem for you, but something is wrong and +you get a link error, e.g.:: + + :(.u_boot_list_2_udevice_2_spl_test5+0x0): undefined reference to + `_u_boot_list_2_driver_2_sandbox_spl_test' + /usr/bin/ld: dts/dt-uclass.o:(.u_boot_list_2_uclass_2_misc+0x8): + undefined reference to `_u_boot_list_2_uclass_driver_2_misc' + +The first one indicates that the device cannot find its driver. This means that +there is a driver 'sandbox_spl_test' but it is not compiled into the build. +Check your Kconfig settings to make sure it is. If you don't want that in the +build, adjust your phase settings, e.g. by using 'u-boot,dm-spl' in the node +to exclude it from the TPL build:: + + spl-test5 { + u-boot,dm-tpl; + compatible = "sandbox,spl-test"; + stringarray = "tpl"; + }; + +We can drop the 'u-boot,dm-tpl' line so this node won't appear in the TPL +devicetree and thus the driver won't be needed. + +The second error above indicates that the MISC uclass is needed by the driver +(since it is in the MISC uclass) but that uclass is not compiled in the build. +The fix above would fix this error too. But if you do want this uclass in the +build, check your Kconfig settings to make sure the uclass is being built +(CONFIG_MISC in this case). + +Another error that can crop up is something like:: + + spl/dts/dt-device.c:257:38: error: invalid application of ‘sizeof’ to + incomplete type ‘struct sandbox_irq_priv’ + 257 | u8 _sandbox_irq_priv_irq_sbox[sizeof(struct sandbox_irq_priv)] + | ^~~~~~ + +This indicates that `struct sandbox_irq_priv` is not defined anywhere. The +solution is to add a DM_HEADER() line, as below, so this is included in the +dt-device.c file:: + + U_BOOT_DRIVER(sandbox_irq) = { + .name = "sandbox_irq", + .id = UCLASS_IRQ, + .of_match = sandbox_irq_ids, + .ops = &sandbox_irq_ops, + .priv_auto = sizeof(struct sandbox_irq_priv), + DM_HEADER(<asm/irq.h>) + }; + +Note that there is no dependency checking on the above, so U-Boot will not +regenerate the dt-device.c file when you update the source file (here, +`irq_sandbox.c`). You need to run `make mrproper` first to get a fresh build. + +Another error that can crop up is something like:: + + spl/dts/dt-device.c:257:38: error: invalid application of ‘sizeof’ to + incomplete type ‘struct sandbox_irq_priv’ + 257 | u8 _sandbox_irq_priv_irq_sbox[sizeof(struct sandbox_irq_priv)] + | ^~~~~~ + +This indicates that `struct sandbox_irq_priv` is not defined anywhere. The +solution is to add a DM_HEADER() line, as below, so this is included in the +dt-device.c file:: + + U_BOOT_DRIVER(sandbox_irq) = { + .name = "sandbox_irq", + .id = UCLASS_IRQ, + .of_match = sandbox_irq_ids, + .ops = &sandbox_irq_ops, + .priv_auto = sizeof(struct sandbox_irq_priv), + DM_HEADER(<asm/irq.h>) + }; + +Note that there is no dependency checking on the above, so U-Boot will not +regenerate the dt-device.c file when you update the source file (here, +`irq_sandbox.c`). You need to run `make mrproper` first to get a fresh build. + Caveats ------- @@ -697,7 +829,7 @@ Internals --------- Generated files -``````````````` +~~~~~~~~~~~~~~~ When enabled, dtoc generates the following five files: @@ -738,7 +870,7 @@ spl/dt-plat.c. CONFIG options -`````````````` +~~~~~~~~~~~~~~ Several CONFIG options are used to control the behaviour of of-platdata, all available for both SPL and TPL: @@ -793,7 +925,7 @@ READ_ONLY the nodes cannot be updated, OF_PLATDATA_NO_BIND is enabled. Data structures -``````````````` +~~~~~~~~~~~~~~~ A few extra data structures are used with of-platdata: @@ -821,7 +953,7 @@ A few extra data structures are used with of-platdata: `device_get_by_ofplat_idx()`. Other changes -````````````` +~~~~~~~~~~~~~ Some other changes are made with of-platdata: |