Re: [PATCH v3 03/16] mfd: mfd-core: match device tree node against reg property

Lee Jones
2020-05-15T10:28:56Z

On Thu, 30 Apr 2020, Michael Walle wrote:

> Hi Lee,
>
> Am 2020-04-23 19:45, schrieb Michael Walle:
> > There might be multiple children with the device tree compatible, for
> > example if a MFD has multiple instances of the same function. In this
> > case only the first is matched and the other children get a wrong
> > of_node reference.
> > Add a new option to match also against the unit address of the child
> > node. Additonally, a new helper OF_MFD_CELL_REG is added.
>
>
> Do you think this is feasible? I guess this is the biggest uncertainty
> for me at the moment in this patch series.

I think it sounds fine in principle. So long as it doesn't change the
existing behaviour when of_reg isn't set.

> > Signed-off-by: Michael Walle <michael@walle.cc>
> > ---
> > drivers/mfd/mfd-core.c | 29 ++++++++++++++++++++---------
> > include/linux/mfd/core.h | 26 ++++++++++++++++++++------
> > 2 files changed, 40 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> > index e735565969b3..4ecb376338f7 100644
> > --- a/drivers/mfd/mfd-core.c
> > +++ b/drivers/mfd/mfd-core.c
> > @@ -117,6 +117,7 @@ static int mfd_add_device(struct device *parent, int
> > id,
> > struct device_node *np = NULL;
> > int ret = -ENOMEM;
> > int platform_id;
> > + u32 of_reg;
> > int r;
> >
> > if (id == PLATFORM_DEVID_AUTO)
> > @@ -151,16 +152,26 @@ static int mfd_add_device(struct device *parent,
> > int id,
> >
> > if (parent->of_node && cell->of_compatible) {
> > for_each_child_of_node(parent->of_node, np) {
> > - if (of_device_is_compatible(np, cell->of_compatible)) {
> > - if (!of_device_is_available(np)) {
> > - /* Ignore disabled devices error free */
> > - ret = 0;
> > - goto fail_alias;
> > - }
> > - pdev->dev.of_node = np;
> > - pdev->dev.fwnode = &np->fwnode;
> > - break;
> > + if (!of_device_is_compatible(np, cell->of_compatible))
> > + continue;
> > +
> > + /* also match the unit address if set */

Please use correct grammar in comments (leaving off the full-stop).

> > + if (cell->of_reg & MFD_OF_REG_VALID) {
> > + if (of_property_read_u32(np, "reg", &of_reg))
> > + continue;
> > + if ((cell->of_reg & MFD_OF_REG_MASK) != of_reg)
> > + continue;
> > }
> > +
> > + if (!of_device_is_available(np)) {
> > + /* Ignore disabled devices error free */
> > + ret = 0;
> > + goto fail_alias;
> > + }
> > +
> > + pdev->dev.of_node = np;
> > + pdev->dev.fwnode = &np->fwnode;
> > + break;
> > }
> > }
> >
> > diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
> > index d01d1299e49d..c2c0ad6b14f3 100644
> > --- a/include/linux/mfd/core.h
> > +++ b/include/linux/mfd/core.h
> > @@ -13,8 +13,11 @@
> > #include <linux/platform_device.h>
> >
> > #define MFD_RES_SIZE(arr) (sizeof(arr) / sizeof(struct resource))
> > +#define MFD_OF_REG_VALID BIT(31)

What about 64bit platforms?

> > +#define MFD_OF_REG_MASK GENMASK(30, 0)
> >
> > -#define MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat,
> > _match)\
> > +#define MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, \
> > + _of_reg, _match) \
> > { \
> > .name = (_name), \
> > .resources = (_res), \
> > @@ -22,24 +25,32 @@
> > .platform_data = (_pdata), \
> > .pdata_size = (_pdsize), \
> > .of_compatible = (_compat), \
> > + .of_reg = (_of_reg), \
> > .acpi_match = (_match), \
> > .id = (_id), \
> > }
> >
> > +#define OF_MFD_CELL_REG(_name, _res, _pdata, _pdsize, _id, _compat, \
> > + _of_reg) \
> > + MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, \
> > + ((_of_reg) | MFD_OF_REG_VALID), NULL) \
> > +
> > #define OF_MFD_CELL(_name, _res, _pdata, _pdsize,_id, _compat) \
> > - MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, NULL) \
> > + MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, \
> > + 0, NULL) \
> >
> > #define ACPI_MFD_CELL(_name, _res, _pdata, _pdsize, _id, _match) \
> > - MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, _match) \
> > + MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, 0, \
> > + _match) \
> >
> > #define MFD_CELL_BASIC(_name, _res, _pdata, _pdsize, _id) \
> > - MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, NULL) \
> > + MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, 0, NULL) \
> >
> > #define MFD_CELL_RES(_name, _res) \
> > - MFD_CELL_ALL(_name, _res, NULL, 0, 0, NULL, NULL) \
> > + MFD_CELL_ALL(_name, _res, NULL, 0, 0, NULL, 0, NULL) \
> >
> > #define MFD_CELL_NAME(_name) \
> > - MFD_CELL_ALL(_name, NULL, NULL, 0, 0, NULL, NULL) \
> > + MFD_CELL_ALL(_name, NULL, NULL, 0, 0, NULL, 0, NULL) \
> >
> > struct irq_domain;
> > struct property_entry;
> > @@ -78,6 +89,9 @@ struct mfd_cell {
> > */
> > const char *of_compatible;
> >
> > + /* matching the reg property if set */

Proper grammar please.

"OF unit address for device matching"

> > + unsigned int of_reg;
> > +
> > /* Matches ACPI */
> > const struct mfd_cell_acpi_match *acpi_match;

--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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