Am Freitag, den 04.09.2015, 12:40 +0300 schrieb Peter Mamonov:
> Hi, Lucas!
>
> On Thu, 03 Sep 2015 17:46:32 +0200
> Lucas Stach <l.stach@xxxxxxxxxxxxxx> wrote:
>
> > Hi Peter.
> >
> > Sorry, but this patch is wrong. You can't just make up completely
> > ad-hoc DT bindings. You are pushing platformdata 1:1 into the DT,
> > which is not how the conversion to DT should be done.
>
> Could you clarify your point? My current understanding is that drivers
> instantiation from a platform code and from a DT are equal approaches,
> which should mirror each other.
>
No not at all. DT bindings are API between the DT and barebox/Linux, so
they can not in all cases mirror platformdata, which we are able to
change at will.
DT instantiation need a well thought through binding, which isn't some
ad-hoc mirroring of the current platformdata.
Normally the binding is established by writing it down in the Linux
kernel Documentation/devicetree/bindings folder (and obviously getting
it through the DT review process).
> >
> > There is also no pre-existing binding for "ata-generic" in the Linux
> > kernel which would define any of those properties.
> >
> > Most likely your IDE controller is inside some SoC specific block,
> > with a specific compatible, which may also handle clocks and other
> > required stuff and that one should instantiate the IDE driver if
> > needed.
>
> I've got your point. However, drivers/ata/pata_of_platform.c from Linux
> also lacks any clock/stuff initialization.
>
If there is already a Linux driver with this binding you can reuse that
one, as it's already established, even if there is no proper
documentation there. If the binding is enough for your use-case that's
okay.
You can however not make any ad-hoc additions to the established
bindings, so if it doesn't fit your needs you need to propose the
addition to the generic binding to DT reviewers, or think about a SoC
specific binding if you need clocks/regulators or other things that
don't belong in a generic binding.
Regards,
Lucas
> Regards,
> Peter
>
>
> >
> > Regards,
> > Lucas
> >
> > Am Donnerstag, den 03.09.2015, 16:38 +0300 schrieb Peter Mamonov:
> > > Signed-off-by: Peter Mamonov <pmamonov@xxxxxxxxx>
> > > ---
> > > drivers/ata/intf_platform_ide.c | 35
> > > +++++++++++++++++++++++++++++++++-- 1 file changed, 33
> > > insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/ata/intf_platform_ide.c
> > > b/drivers/ata/intf_platform_ide.c index 0d392d8..f20e0e0 100644
> > > --- a/drivers/ata/intf_platform_ide.c
> > > +++ b/drivers/ata/intf_platform_ide.c
> > > @@ -29,6 +29,7 @@
> > > #include <ata_drive.h>
> > > #include <platform_ide.h>
> > > #include <linux/err.h>
> > > +#include <of.h>
> > >
> > > /**
> > > * Setup the register specific addresses for an ATA like divice
> > > @@ -85,10 +86,31 @@ static int platform_ide_probe(struct device_d
> > > *dev) void *reg_base, *alt_base = NULL;
> > > struct resource *reg, *alt;
> > > int mmio = 0;
> > > + struct device_node *dn = dev->device_node;
> > > + u32 tmp32;
> > >
> > > if (pdata == NULL) {
> > > - dev_err(dev, "No platform data. Cannot
> > > continue\n");
> > > - return -EINVAL;
> > > + /* try to get platform data from the device tree */
> > > + if (dn == NULL) {
> > > + dev_err(dev, "No platform data. Cannot
> > > continue\n");
> > > + return -EINVAL;
> > > + }
> > > +
> > > + pdata = xzalloc(sizeof(struct ide_port_info));
> > > +
> > > + if (!pdata) {
> > > + dev_err(dev, "Platform data allocation
> > > failed\n");
> > > + return -ENOMEM;
> > > + }
> > > + device_add_data(dev, pdata, sizeof(struct
> > > ide_port_info)); +
> > > + if (of_property_read_bool(dn, "dataif-be"))
> > > + pdata->dataif_be = 1;
> > > +
> > > + if (of_property_read_u32(dn, "reg-shift", &tmp32)
> > > == 0)
> > > + pdata->ioport_shift = (unsigned)tmp32;
> > > +
> > > + dev->platform_data = pdata;
> > > }
> > >
> > > reg_base = dev_request_mem_region(dev, 0);
> > > @@ -136,9 +158,18 @@ static int platform_ide_probe(struct device_d
> > > *dev) return rc;
> > > }
> > >
> > > +static __maybe_unused struct of_device_id platform_ide_dt_ids[] = {
> > > + {
> > > + .compatible = "ata-generic",
> > > + }, {
> > > + /* sentinel */
> > > + }
> > > +};
> > > +
> > > static struct driver_d platform_ide_driver = {
> > > .name = "ide_intf",
> > > .probe = platform_ide_probe,
> > > + .of_compatible = DRV_OF_COMPAT(platform_ide_dt_ids),
> > > };
> > > device_platform_driver(platform_ide_driver);
> > >
> >
>
--
Pengutronix e.K. | Lucas Stach |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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