From patchwork Fri Jun 19 14:55:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Walter Lozano X-Patchwork-Id: 242701 List-Id: U-Boot discussion From: walter.lozano at collabora.com (Walter Lozano) Date: Fri, 19 Jun 2020 11:55:46 -0300 Subject: [PATCH v2 05/14] dm: doc: update of-plat with the support for driver aliases In-Reply-To: <20200619145555.863-1-walter.lozano@collabora.com> References: <20200619145555.863-1-walter.lozano@collabora.com> Message-ID: <20200619145555.863-6-walter.lozano@collabora.com> Update the documentation with the support for driver aliases using U_BOOT_DRIVER_ALIAS. Signed-off-by: Walter Lozano Reviewed-by: Simon Glass --- doc/driver-model/of-plat.rst | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/doc/driver-model/of-plat.rst b/doc/driver-model/of-plat.rst index 034a68bb4e..376d4409a5 100644 --- a/doc/driver-model/of-plat.rst +++ b/doc/driver-model/of-plat.rst @@ -183,6 +183,17 @@ via U_BOOT_DRIVER(). This effectively means that a U_BOOT_DRIVER() with a it to a valid name for C) is needed, so a dedicated driver is required for each 'compatible' string. +In order to make this a bit more flexible U_BOOT_DRIVER_ALIAS macro can be +used to declare an alias for a driver name, typically a 'compatible' string. +This macro produces no code, but it is by dtoc tool. + +During the build process dtoc parses both U_BOOT_DRIVER and U_BOOT_DRIVER_ALIAS +to build a list of valid driver names and driver aliases. If the 'compatible' +string used for a device does not not match a valid driver name, it will be +checked against the list of driver aliases in order to get the right driver +name to use. If in this step there is no match found a warning is issued to +avoid run-time failures. + Where a node has multiple compatible strings, a #define is used to make them equivalent, e.g.: @@ -269,7 +280,7 @@ For example: }; U_BOOT_DRIVER(mmc_drv) = { - .name = "vendor_mmc", /* matches compatible string */ + .name = "mmc_drv", .id = UCLASS_MMC, .of_match = mmc_ids, .ofdata_to_platdata = mmc_ofdata_to_platdata, @@ -278,6 +289,7 @@ For example: .platdata_auto_alloc_size = sizeof(struct mmc_platdata), }; + U_BOOT_DRIVER_ALIAS(mmc_drv, vendor_mmc) /* matches compatible string */ Note that struct mmc_platdata is defined in the C file, not in a header. This is to avoid needing to include dt-structs.h in a header file. The idea is to