Hi Simon,
On 7/4/21 3:19 PM, Simon Glass wrote:
When things go wrong it can be confusing to figure out what to change. Add a few more details to the documentation.
Fix a 'make htmldocs' warning while we are here.
Signed-off-by: Simon Glass sjg@chromium.org
doc/develop/driver-model/of-plat.rst | 53 ++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+)
diff --git a/doc/develop/driver-model/of-plat.rst b/doc/develop/driver-model/of-plat.rst index 74f1932473b..e2763965839 100644 --- a/doc/develop/driver-model/of-plat.rst +++ b/doc/develop/driver-model/of-plat.rst @@ -597,6 +597,59 @@ as a macro included in the driver definition::
+Problems +--------
+In some cases you will you see something like this::
- WARNING: the driver rockchip_rk3188_grf was not found in the driver list
+The driver list is a list of drivers, each with a name. The name is in the +U_BOOT_DRIVER() declaration, repeated twice, one in brackets and once as the +.name member. For example, in the following declaration the driver name is +`rockchip_rk3188_grf`::
- U_BOOT_DRIVER(rockchip_rk3188_grf) = {
.name = "rockchip_rk3188_grf",.id = UCLASS_SYSCON,.of_match = rk3188_syscon_ids + 1,.bind = rk3188_syscon_bind_of_plat,- };
+The first name U_BOOT_DRIVER(xx) is used to create a linker symbol so that the +driver can be accessed at build-time without any overhead. The second one +(.name = "xx") is used at runtime when something wants to print out the driver +name.
+The dtoc tool expects to be able to find a driver for each compatible string in +the devicetree. For example, if the devicetree has::
- grf: grf@20008000 {
compatible = "rockchip,rk3188-grf", "syscon";reg = <0x20008000 0x200>;u-boot,dm-spl;- };
+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.
+Various things can cause dtoc to fail to find the driver and it tries to +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+Without a compatible string a driver cannot be used by dtoc, even if the +compatible string is not actually needed at runtime.
+If the problem is simply that there are multiple compatible strings, the +DM_DRIVER_ALIAS() macro can be used to tell dtoc about this and avoid a problem.
+Checks are also made 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.
This paragraph sound strange, maybe
"Checks are are also made to confirm that the referenced driver..."
but your English is better than mine.
Reviewed-by: Walter Lozano walter.lozano@collabora.com
Regards,
Walter
Caveats