diff mbox

[1/2] Add a matching set of device_ functions for determining mac/phy

Message ID 1439417187-21411-2-git-send-email-jeremy.linton@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jeremy Linton Aug. 12, 2015, 10:06 p.m. UTC
OF has some helper functions for parsing MAC and PHY settings.
In cases where the platform is providing this information rather
than the device itself, there needs to be similar functions for ACPI.

These functions are slightly modified versions of the ones in
of_net which can use information provided via DT or ACPI.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
 drivers/base/property.c  | 73 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/property.h |  4 +++
 2 files changed, 77 insertions(+)

Comments

Florian Fainelli Aug. 12, 2015, 10:13 p.m. UTC | #1
On 12/08/15 15:06, Jeremy Linton wrote:
> OF has some helper functions for parsing MAC and PHY settings.
> In cases where the platform is providing this information rather
> than the device itself, there needs to be similar functions for ACPI.
> 
> These functions are slightly modified versions of the ones in
> of_net which can use information provided via DT or ACPI.
> 
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---

[snip]

> +
> +static void *device_get_mac_addr(struct device *dev,
> +				 const char *name, char *addr,
> +				 int alen)
> +{
> +	int ret = device_property_read_u8_array(dev, name, addr, alen);
> +
> +	if (ret == 0 && is_valid_ether_addr(addr))
> +		return addr;
> +	return NULL;

The DT counterpart has an additional check on the properly length to be
ETH_ALEN, you might want to have such check here for consistency and
correctness.

Other than that, this looks good to me.
Robin Murphy Aug. 13, 2015, 11:57 a.m. UTC | #2
Hi Jeremy,

On 12/08/15 23:06, Jeremy Linton wrote:
[...]
> +static void *device_get_mac_addr(struct device *dev,
> +				 const char *name, char *addr,
> +				 int alen)
> +{
> +	int ret = device_property_read_u8_array(dev, name, addr, alen);
> +
> +	if (ret == 0 && is_valid_ether_addr(addr))
> +		return addr;
> +	return NULL;
> +}

Not sure I understand the logic here - "return the same thing we were 
given if we updated it, or null if we didn't". It's only indicating 
success/failure (the caller can perfectly well cast its own buffer to a 
void * if it needs to), so why wouldn't you just return a normal int 
error code?

> +/**
> + * Search the device tree for the best MAC address to use.  'mac-address' is
> + * checked first, because that is supposed to contain to "most recent" MAC
> + * address. If that isn't set, then 'local-mac-address' is checked next,
> + * because that is the default address.  If that isn't set, then the obsolete
> + * 'address' is checked, just in case we're using an old device tree.
> + *
> + * Note that the 'address' property is supposed to contain a virtual address of
> + * the register set, but some DTS files have redefined that property to be the
> + * MAC address.
> + *
> + * All-zero MAC addresses are rejected, because those could be properties that
> + * exist in the device tree, but were not set by U-Boot.  For example, the
> + * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
> + * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
> + * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
> + * but is all zeros.
> +*/
> +void *device_get_mac_address(struct device *dev, char *addr, int alen)
> +{
> +	addr = device_get_mac_addr(dev, "mac-address", addr, alen);
> +	if (addr)
> +		return addr;
> +
> +	addr = device_get_mac_addr(dev, "local-mac-address", addr, alen);
> +	if (addr)
> +		return addr;
> +
> +	return device_get_mac_addr(dev, "address", addr, alen);
> +}
> +EXPORT_SYMBOL(device_get_mac_address);

Same here, it's not at all apparent why this should return a void * 
instead of an int (or even possibly bool). of_get_mac_address is giving 
its caller back a _new_ pointer they didn't know about before; this isn't.

Robin.
Jeremy Linton Aug. 13, 2015, 2:24 p.m. UTC | #3
Hello Robin,

On 08/13/2015 06:57 AM, Robin Murphy wrote:
>> +static void *device_get_mac_addr(struct device *dev,
>> +				 const char *name, char *addr,
>> +				 int alen)
>> +{
>> +	int ret = device_property_read_u8_array(dev, name, addr, alen);
>> +
>> +	if (ret == 0 && is_valid_ether_addr(addr))
>> +		return addr;
>> +	return NULL;
>> +}
>
> Not sure I understand the logic here - "return the same thing we were
> given if we updated it, or null if we didn't". It's only indicating
> success/failure (the caller can perfectly well cast its own buffer to a
> void * if it needs to), so why wouldn't you just return a normal int
> error code?


	No particular reason, other than initially I was trying to keep the 
function as similar as possible to the one in of_net. AKA copy paste 
job. I can convert the return types, but I was trying for a simple 
function rename. That way the users of the of version could be converted 
with relative ease, and the drivers which invented their own version of 
these functions could be changed to use this instead. Of course, that 
plan took a blow, when I added the addr/alen parameters.

	Same thing applies for the other function.
Jeremy Linton Aug. 14, 2015, 3:55 p.m. UTC | #4
On 08/12/2015 05:13 PM, Florian Fainelli wrote:
> On 12/08/15 15:06, Jeremy Linton wrote:
>> +
>> +static void *device_get_mac_addr(struct device *dev,
>> +				 const char *name, char *addr,
>> +				 int alen)
>> +{
>> +	int ret = device_property_read_u8_array(dev, name, addr, alen);
>> +
>> +	if (ret == 0 && is_valid_ether_addr(addr))
>> +		return addr;
>> +	return NULL;
>
> The DT counterpart has an additional check on the properly length to be
> ETH_ALEN, you might want to have such check here for consistency and
> correctness.

I will add it back,

Thanks,
diff mbox

Patch

diff --git a/drivers/base/property.c b/drivers/base/property.c
index f3f6d16..2e8cd14 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -16,6 +16,8 @@ 
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/property.h>
+#include <linux/etherdevice.h>
+#include <linux/phy.h>
 
 /**
  * device_add_property_set - Add a collection of properties to a device object.
@@ -533,3 +535,74 @@  bool device_dma_is_coherent(struct device *dev)
 	return coherent;
 }
 EXPORT_SYMBOL_GPL(device_dma_is_coherent);
+
+/**
+ * device_get_phy_mode - Get phy mode for given device_node
+ * @dev:	Pointer to the given device
+ *
+ * The function gets phy interface string from property 'phy-mode' or
+ * 'phy-connection-type', and return its index in phy_modes table, or errno in
+ * error case.
+ */
+int device_get_phy_mode(struct device *dev)
+{
+	const char *pm;
+	int err, i;
+
+	err = device_property_read_string(dev, "phy-mode", &pm);
+	if (err < 0)
+		err = device_property_read_string(dev,
+						  "phy-connection-type", &pm);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
+		if (!strcasecmp(pm, phy_modes(i)))
+			return i;
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(device_get_phy_mode);
+
+static void *device_get_mac_addr(struct device *dev,
+				 const char *name, char *addr,
+				 int alen)
+{
+	int ret = device_property_read_u8_array(dev, name, addr, alen);
+
+	if (ret == 0 && is_valid_ether_addr(addr))
+		return addr;
+	return NULL;
+}
+
+/**
+ * Search the device tree for the best MAC address to use.  'mac-address' is
+ * checked first, because that is supposed to contain to "most recent" MAC
+ * address. If that isn't set, then 'local-mac-address' is checked next,
+ * because that is the default address.  If that isn't set, then the obsolete
+ * 'address' is checked, just in case we're using an old device tree.
+ *
+ * Note that the 'address' property is supposed to contain a virtual address of
+ * the register set, but some DTS files have redefined that property to be the
+ * MAC address.
+ *
+ * All-zero MAC addresses are rejected, because those could be properties that
+ * exist in the device tree, but were not set by U-Boot.  For example, the
+ * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
+ * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
+ * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
+ * but is all zeros.
+*/
+void *device_get_mac_address(struct device *dev, char *addr, int alen)
+{
+	addr = device_get_mac_addr(dev, "mac-address", addr, alen);
+	if (addr)
+		return addr;
+
+	addr = device_get_mac_addr(dev, "local-mac-address", addr, alen);
+	if (addr)
+		return addr;
+
+	return device_get_mac_addr(dev, "address", addr, alen);
+}
+EXPORT_SYMBOL(device_get_mac_address);
diff --git a/include/linux/property.h b/include/linux/property.h
index 76ebde9..a59c6ee 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -166,4 +166,8 @@  void device_add_property_set(struct device *dev, struct property_set *pset);
 
 bool device_dma_is_coherent(struct device *dev);
 
+int device_get_phy_mode(struct device *dev);
+
+void *device_get_mac_address(struct device *dev, char *addr, int alen);
+
 #endif /* _LINUX_PROPERTY_H_ */