From 5ca9ec5d9c27a338104a61428822645c6da043ca Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Fri, 7 May 2021 11:56:15 +0200 Subject: [PATCH] kernel: serial: Update the way we create the misc device name This has also been updated in the labs. Signed-off-by: Miquel Raynal --- labs/kernel-serial-output/kernel-serial-output.tex | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/labs/kernel-serial-output/kernel-serial-output.tex b/labs/kernel-serial-output/kernel-serial-output.tex index dbe7e62cc..354a10bbb 100644 --- a/labs/kernel-serial-output/kernel-serial-output.tex +++ b/labs/kernel-serial-output/kernel-serial-output.tex @@ -63,7 +63,15 @@ \section{Misc driver registration} \begin{itemize} \item To get an automatically assigned minor number. \item To specify a name for the device file in {\em devtmpfs}. We - "serial-\%llx", platform\_get\_resource(pdev, IORESOURCE\_MEM, 0)->start)}. + propose to use: + \begin{verbatim} +struct resource *res; +[...] +res = platform_get_resource(pdev, IORESOURCE_MEM, 0); +/* Error handling */ +[...] +devm_kasprintf(&pdev->dev, GFP_KERNEL, "serial-\%llx", res->start); + \end{verbatim} \kfunc{devm_kasprintf} allocates a buffer and runs \kfunc{kasprintf} to fill its contents. \kfunc{platform_get_resource} is used to retrieve the device physical address from the device tree.