On Sun, Feb 09, 2025 at 10:58:50PM +0100, J. Neuschäfer via B4 Relay wrote: > From: "J. Neuschäfer" <j...@posteo.net> > > Historically, devicetree nodes representing the Freescale Enhanced > Local Bus Controller (eLBC) have compatible strings such as: > > compatible = "fsl,mpc8313-elbc", "fsl,elbc", "simple-bus"; > > The "simple-bus" string causes the bus to be populated, and the memory > devices contained within it to be discovered. The eLBC bus (as > represented in device trees) differs from a simple-bus in a few ways, > though: > > - Addresses are not simple/linear: The first cell of an address is a > chip select, the second is an linear address within the space thus > selected. Representing 1,0 as 100000000, for example, would decrease > readability[1]. > - It is expected that the devices on a simple-bus "can be accessed > directly without additional configuration required"[2], but the eLBC > needs some configuration. > > To accommodate devicetrees that declare an eLBC without "simple-bus", > explicitly populate the bus in the eLBC driver. > > [1]: dtc makes such a suggestion opon encountering an eLBC > [2]: Quoting the Devicetree Specification Release v0.3 > > Signed-off-by: J. Neuschäfer <j...@posteo.net> > ---
Due to advice from Crystal Wood and Rob Herring[1], I reached the conclusion that this patch is not necessary. [1]: https://lore.kernel.org/lkml/Z7ILej_AJYot_wKP@probook/ > arch/powerpc/sysdev/fsl_lbc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/sysdev/fsl_lbc.c b/arch/powerpc/sysdev/fsl_lbc.c > index > 217cea150987df1e1b5c6dbf9e9a1607dd5ce49b..2007ced997fcf0c7059e5b780893b530764dc8b2 > 100644 > --- a/arch/powerpc/sysdev/fsl_lbc.c > +++ b/arch/powerpc/sysdev/fsl_lbc.c > @@ -20,6 +20,7 @@ > #include <linux/of.h> > #include <linux/of_address.h> > #include <linux/of_irq.h> > +#include <linux/of_platform.h> > #include <linux/slab.h> > #include <linux/sched.h> > #include <linux/platform_device.h> > @@ -336,7 +337,7 @@ static int fsl_lbc_ctrl_probe(struct platform_device *dev) > /* Enable interrupts for any detected events */ > out_be32(&fsl_lbc_ctrl_dev->regs->lteir, LTEIR_ENABLE); > > - return 0; > + return devm_of_platform_populate(&dev->dev); > > err1: > free_irq(fsl_lbc_ctrl_dev->irq[0], fsl_lbc_ctrl_dev); > > --- > base-commit: 7ccde445dddcca030cd6ed66974bb80915ad9dd5 > change-id: 20250209-localbus-94a6ebb04c12 > > Best regards, > -- > J. Neuschäfer <j...@posteo.net> > >
