Re: [PATCH] driver core: property: support for generic property

From: Heikki Krogerus
Date: Tue Jan 13 2015 - 04:37:38 EST

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On Tue, Jan 13, 2015 at 10:35:09AM +0100, Rafael J. Wysocki wrote:
> On Monday, January 12, 2015 01:15:44 PM Heikki Krogerus wrote:
> > This extends the Unified Property Interface by adding
> > "Generic Property" to it for cases where device tree or ACPI
> > are not being used.
> >
> > That makes the Unified Property Interface cover most of the
> > cases where information is extracted from custom
> > platform_data in the drivers, i.e. removing also the need
> > for them to handle custom platform data separately.
>
> I'm not sure I understand that correctly. Do you mean that it is possible to
> reduce code duplication between drivers this way?

I wan't to replace platform_data with unified device properties. So I
wan't to replace this kind of code in the drivers:

if (pdata)
val = pdata->val;
else
device_property_read_u32(dev, "magic", &val);

With just:

device_property_read_u32(dev, "magic", &val);

> > Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> > ---
> > drivers/base/property.c | 188 +++++++++++++++++++++++++++++++++++++++++------
> > include/linux/device.h | 2 +
> > include/linux/property.h | 13 ++++
> > 3 files changed, 182 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/base/property.c b/drivers/base/property.c
> > index c458458..99990e2 100644
> > --- a/drivers/base/property.c
> > +++ b/drivers/base/property.c
> > @@ -15,6 +15,129 @@
> > #include <linux/acpi.h>
> > #include <linux/of.h>
> >
> > +static struct dev_gen_prop *dev_prop_get(struct device *dev, const char *name)
> > +{
> > + struct dev_gen_prop *prop;
> > +
> > + if (!dev->gen_prop)
> > + return NULL;
> > +
> > + for (prop = dev->gen_prop; prop->name; prop++)
> > + if (!strcmp(name, prop->name))
> > + return prop;
> > + return NULL;
> > +}
> > +
> > +static int dev_prop_copy_array_u8(const char **src, u8 *val, size_t nval)
> > +{
> > + int ret;
> > + int i;
> > +
> > + for (i = 0; i < nval; i++) {
> > + if (!src[i])
> > + return -EOVERFLOW;
> > + ret = kstrtou8(src[i], 0, &val[i]);
> > + if (ret)
> > + return ret;
> > + }
> > + return 0;
> > +}
> > +
> > +static int dev_prop_copy_array_u16(const char **src, u16 *val, size_t nval)
> > +{
> > + int ret;
> > + int i;
> > +
> > + for (i = 0; i < nval; i++) {
> > + if (!src[i])
> > + return -EOVERFLOW;
> > + ret = kstrtou16(src[i], 0, &val[i]);
> > + if (ret)
> > + return ret;
> > + }
> > + return 0;
> > +}
> > +
> > +static int dev_prop_copy_array_u32(const char **src, u32 *val, size_t nval)
> > +{
> > + int ret;
> > + int i;
> > +
> > + for (i = 0; i < nval; i++) {
> > + if (!src[i])
> > + return -EOVERFLOW;
> > + ret = kstrtou32(src[i], 0, &val[i]);
> > + if (ret)
> > + return ret;
> > + }
> > + return 0;
> > +}
> > +
> > +static int dev_prop_copy_array_u64(const char **src, u64 *val, size_t nval)
> > +{
> > + int ret;
> > + int i;
> > +
> > + for (i = 0; i < nval; i++) {
> > + if (!src[i])
> > + return -EOVERFLOW;
> > + ret = kstrtou64(src[i], 0, &val[i]);
> > + if (ret)
> > + return ret;
> > + }
> > + return 0;
> > +}
> > +
> > +static int dev_prop_copy_array_string(const char **src, const char **val,
> > + size_t nval)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < nval; i++) {
> > + if (!src[i])
> > + return -EOVERFLOW;
> > + val[i] = src[i];
> > + }
> > + return 0;
> > +}
> > +
> > +static int dev_prop_read_array(struct device *dev, const char *name,
> > + enum dev_prop_type type, void *val, size_t nval)
> > +{
> > + struct dev_gen_prop *prop;
> > + int ret = 0;
> > +
> > + prop = dev_prop_get(dev, name);
> > + if (!prop)
> > + return -ENODATA;
> > +
> > + if (prop->type != type)
> > + return -EPROTO;
> > +
> > + switch (prop->type) {
> > + case DEV_PROP_U8:
> > + ret = dev_prop_copy_array_u8(prop->val, (u8 *)val, nval);
> > + break;
> > + case DEV_PROP_U16:
> > + ret = dev_prop_copy_array_u16(prop->val, (u16 *)val, nval);
> > + break;
> > + case DEV_PROP_U32:
> > + ret = dev_prop_copy_array_u32(prop->val, (u32 *)val, nval);
> > + break;
> > + case DEV_PROP_U64:
> > + ret = dev_prop_copy_array_u64(prop->val, (u64 *)val, nval);
> > + break;
> > + case DEV_PROP_STRING:
> > + ret = dev_prop_copy_array_string(prop->val, (const char **)val,
> > + nval);
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + break;
> > + }
> > + return ret;
> > +}
> > +
> > /**
> > * device_property_present - check if a property of a device is present
> > * @dev: Device whose property is being checked
> > @@ -26,8 +149,9 @@ bool device_property_present(struct device *dev, const char *propname)
> > {
> > if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> > return of_property_read_bool(dev->of_node, propname);
> > -
> > - return !acpi_dev_prop_get(ACPI_COMPANION(dev), propname, NULL);
> > + if (ACPI_HANDLE(dev))
> > + return !acpi_dev_prop_get(ACPI_COMPANION(dev), propname, NULL);
> > + return !!dev_prop_get(dev, propname);
> > }
> > EXPORT_SYMBOL_GPL(device_property_present);
> >
> > @@ -51,13 +175,6 @@ EXPORT_SYMBOL_GPL(fwnode_property_present);
> > (val) ? of_property_read_##type##_array((node), (propname), (val), (nval)) \
> > : of_property_count_elems_of_size((node), (propname), sizeof(type))
> >
> > -#define DEV_PROP_READ_ARRAY(_dev_, _propname_, _type_, _proptype_, _val_, _nval_) \
> > - IS_ENABLED(CONFIG_OF) && _dev_->of_node ? \
> > - (OF_DEV_PROP_READ_ARRAY(_dev_->of_node, _propname_, _type_, \
> > - _val_, _nval_)) : \
> > - acpi_dev_prop_read(ACPI_COMPANION(_dev_), _propname_, \
> > - _proptype_, _val_, _nval_)
> > -
>
> The macro was used here for a reason. Can't you replace it with an extended
> macro instead?
>
> > /**
> > * device_property_read_u8_array - return a u8 array property of a device
> > * @dev: Device to get the property of
> > @@ -77,7 +194,13 @@ EXPORT_SYMBOL_GPL(fwnode_property_present);
> > int device_property_read_u8_array(struct device *dev, const char *propname,
> > u8 *val, size_t nval)
> > {
> > - return DEV_PROP_READ_ARRAY(dev, propname, u8, DEV_PROP_U8, val, nval);
> > + if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> > + return OF_DEV_PROP_READ_ARRAY(dev->of_node, propname, u8,
> > + val, nval);
> > + if (ACPI_HANDLE(dev))
> > + return acpi_dev_prop_read(ACPI_COMPANION(dev), propname,
> > + DEV_PROP_U8, val, nval);
> > + return dev_prop_read_array(dev, propname, DEV_PROP_U8, val, nval);
> > }
> > EXPORT_SYMBOL_GPL(device_property_read_u8_array);
> >
> > @@ -100,7 +223,13 @@ EXPORT_SYMBOL_GPL(device_property_read_u8_array);
> > int device_property_read_u16_array(struct device *dev, const char *propname,
> > u16 *val, size_t nval)
> > {
> > - return DEV_PROP_READ_ARRAY(dev, propname, u16, DEV_PROP_U16, val, nval);
> > + if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> > + return OF_DEV_PROP_READ_ARRAY(dev->of_node, propname, u16, val,
> > + nval);
> > + if (ACPI_HANDLE(dev))
> > + return acpi_dev_prop_read(ACPI_COMPANION(dev), propname,
> > + DEV_PROP_U16, val, nval);
> > + return dev_prop_read_array(dev, propname, DEV_PROP_U16, val, nval);
> > }
> > EXPORT_SYMBOL_GPL(device_property_read_u16_array);
> >
> > @@ -123,7 +252,13 @@ EXPORT_SYMBOL_GPL(device_property_read_u16_array);
> > int device_property_read_u32_array(struct device *dev, const char *propname,
> > u32 *val, size_t nval)
> > {
> > - return DEV_PROP_READ_ARRAY(dev, propname, u32, DEV_PROP_U32, val, nval);
> > + if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> > + return OF_DEV_PROP_READ_ARRAY(dev->of_node, propname, u32, val,
> > + nval);
> > + if (ACPI_HANDLE(dev))
> > + return acpi_dev_prop_read(ACPI_COMPANION(dev), propname,
> > + DEV_PROP_U32, val, nval);
> > + return dev_prop_read_array(dev, propname, DEV_PROP_U32, val, nval);
> > }
> > EXPORT_SYMBOL_GPL(device_property_read_u32_array);
> >
> > @@ -146,7 +281,13 @@ EXPORT_SYMBOL_GPL(device_property_read_u32_array);
> > int device_property_read_u64_array(struct device *dev, const char *propname,
> > u64 *val, size_t nval)
> > {
> > - return DEV_PROP_READ_ARRAY(dev, propname, u64, DEV_PROP_U64, val, nval);
> > + if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> > + return OF_DEV_PROP_READ_ARRAY(dev->of_node, propname, u64, val,
> > + nval);
> > + if (ACPI_HANDLE(dev))
> > + return acpi_dev_prop_read(ACPI_COMPANION(dev), propname,
> > + DEV_PROP_U64, val, nval);
> > + return dev_prop_read_array(dev, propname, DEV_PROP_U64, val, nval);
> > }
> > EXPORT_SYMBOL_GPL(device_property_read_u64_array);
> >
> > @@ -169,10 +310,13 @@ EXPORT_SYMBOL_GPL(device_property_read_u64_array);
> > int device_property_read_string_array(struct device *dev, const char *propname,
> > const char **val, size_t nval)
> > {
> > - return IS_ENABLED(CONFIG_OF) && dev->of_node ?
> > - of_property_read_string_array(dev->of_node, propname, val, nval) :
> > - acpi_dev_prop_read(ACPI_COMPANION(dev), propname,
> > - DEV_PROP_STRING, val, nval);
> > + if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> > + return of_property_read_string_array(dev->of_node, propname,
> > + val, nval);
> > + if (ACPI_HANDLE(dev))
> > + return acpi_dev_prop_read(ACPI_COMPANION(dev), propname,
> > + DEV_PROP_STRING, val, nval);
> > + return dev_prop_read_array(dev, propname, DEV_PROP_STRING, val, nval);
> > }
> > EXPORT_SYMBOL_GPL(device_property_read_string_array);
> >
> > @@ -193,10 +337,12 @@ EXPORT_SYMBOL_GPL(device_property_read_string_array);
> > int device_property_read_string(struct device *dev, const char *propname,
> > const char **val)
> > {
> > - return IS_ENABLED(CONFIG_OF) && dev->of_node ?
> > - of_property_read_string(dev->of_node, propname, val) :
> > - acpi_dev_prop_read(ACPI_COMPANION(dev), propname,
> > - DEV_PROP_STRING, val, 1);
> > + if (IS_ENABLED(CONFIG_OF) && dev->of_node)
> > + return of_property_read_string(dev->of_node, propname, val);
> > + if (ACPI_HANDLE(dev))
> > + return acpi_dev_prop_read(ACPI_COMPANION(dev), propname,
> > + DEV_PROP_STRING, val, 1);
> > + return dev_prop_read_array(dev, propname, DEV_PROP_STRING, val, 1);
> > }
> > EXPORT_SYMBOL_GPL(device_property_read_string);
> >
> > diff --git a/include/linux/device.h b/include/linux/device.h
> > index fb50673..bd1e292 100644
> > --- a/include/linux/device.h
> > +++ b/include/linux/device.h
> > @@ -27,6 +27,7 @@
> > #include <linux/ratelimit.h>
> > #include <linux/uidgid.h>
> > #include <linux/gfp.h>
> > +#include <linux/property.h>
> > #include <asm/device.h>
> >
> > struct device;
> > @@ -780,6 +781,7 @@ struct device {
> >
> > struct device_node *of_node; /* associated device tree node */
> > struct acpi_dev_node acpi_node; /* associated ACPI device node */
> > + struct dev_gen_prop *gen_prop;
> >
> > dev_t devt; /* dev_t, creates the sysfs "dev" */
> > u32 id; /* device instance */
> > diff --git a/include/linux/property.h b/include/linux/property.h
> > index a6a3d98..6ac8e508 100644
> > --- a/include/linux/property.h
> > +++ b/include/linux/property.h
> > @@ -26,6 +26,19 @@ enum dev_prop_type {
> > DEV_PROP_MAX,
> > };
> >
> > +/**
> > + * struct dev_gen_prop - Generic Device Property
> > + * @name: property name
> > + * @val: value array
> > + *
> > + * Used when of_node and acpi_node are missing.
> > + */
> > +struct dev_gen_prop {
> > + enum dev_prop_type type;
> > + const char *name;
> > + const char **val;
> > +};
> > +
> > bool device_property_present(struct device *dev, const char *propname);
> > int device_property_read_u8_array(struct device *dev, const char *propname,
> > u8 *val, size_t nval);
> >
>
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.

--
heikki
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Next message: Michael S. Tsirkin: "Re: [PATCH v2 22/40] tile: fix put_user sparse errors"
Previous message: Paul E. McKenney: "Re: [PATCH] rcu_tree: avoid touch rnp->completed when starts a new GP"
In reply to: Rafael J. Wysocki: "Re: [PATCH] driver core: property: support for generic property"
Next in thread: Heikki Krogerus: "Re: [PATCH] driver core: property: support for generic property"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]