Hi,

On Monday 29 July 2013 09:21 PM, Sylwester Nawrocki wrote:

On 07/26/2013 02:49 PM, Kishon Vijay Abraham I wrote:

quoted

The PHY framework provides a set of APIs for the PHY drivers to
create/destroy a PHY and APIs for the PHY users to obtain a reference to the
PHY with or without using phandle. For dt-boot, the PHY drivers should
also register *PHY provider* with the framework.

PHY drivers should create the PHY by passing id and ops like init, exit,
power_on and power_off. This framework is also pm runtime enabled.

The documentation for the generic PHY framework is added in
Documentation/phy.txt and the documentation for dt binding can be found at
Documentation/devicetree/bindings/phy/phy-bindings.txt

Cc: Tomasz Figa <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kishon Vijay Abraham I <redacted>
Acked-by: Felipe Balbi <redacted>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
 .../devicetree/bindings/phy/phy-bindings.txt       |   66 ++
 Documentation/phy.txt                              |  166 +++++
 MAINTAINERS                                        |    8 +
 drivers/Kconfig                                    |    2 +
 drivers/Makefile                                   |    2 +
 drivers/phy/Kconfig                                |   18 +
 drivers/phy/Makefile                               |    5 +
 drivers/phy/phy-core.c                             |  714 ++++++++++++++++++++
 include/linux/phy/phy.h                            |  270 ++++++++
 9 files changed, 1251 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/phy-bindings.txt
 create mode 100644 Documentation/phy.txt
 create mode 100644 drivers/phy/Kconfig
 create mode 100644 drivers/phy/Makefile
 create mode 100644 drivers/phy/phy-core.c
 create mode 100644 include/linux/phy/phy.h

diff --git a/Documentation/devicetree/bindings/phy/phy-bindings.txt b/Documentation/devicetree/bindings/phy/phy-bindings.txt
new file mode 100644
index 0000000..8ae844f
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/phy-bindings.txt

@@ -0,0 +1,66 @@
+This document explains only the device tree data binding. For general
+information about PHY subsystem refer to Documentation/phy.txt

[...]

quoted

@@ -0,0 +1,166 @@
+			    PHY SUBSYSTEM
+		  Kishon Vijay Abraham I <kishon@ti.com>
+
+This document explains the Generic PHY Framework along with the APIs provided,
+and how-to-use.
+
+1. Introduction
+
+*PHY* is the abbreviation for physical layer. It is used to connect a device
+to the physical medium e.g., the USB controller has a PHY to provide functions
+such as serialization, de-serialization, encoding, decoding and is responsible
+for obtaining the required data transmission rate. Note that some USB
+controllers have PHY functionality embedded into it and others use an external
+PHY. Other peripherals that use PHY include Wireless LAN, Ethernet,
+SATA etc.
+
+The intention of creating this framework is to bring the PHY drivers spread
+all over the Linux kernel to drivers/phy to increase code re-use and for
+better code maintainability.
+
+This framework will be of use only to devices that use external PHY (PHY
+functionality is not embedded within the controller).
+
+2. Registering/Unregistering the PHY provider
+
+PHY provider refers to an entity that implements one or more PHY instances.
+For the simple case where the PHY provider implements only a single instance of
+the PHY, the framework provides its own implementation of of_xlate in
+of_phy_simple_xlate. If the PHY provider implements multiple instances, it
+should provide its own implementation of of_xlate. of_xlate is used only for
+dt boot case.
+
+#define of_phy_provider_register(dev, xlate)    \
+        __of_phy_provider_register((dev), THIS_MODULE, (xlate))
+
+#define devm_of_phy_provider_register(dev, xlate)       \
+        __of_phy_provider_register((dev), THIS_MODULE, (xlate))

This needs to be:

	__devm_of_phy_provider_register((dev), THIS_MODULE, (xlate))

as Kamil pointed out. We've tested it here with v9 and it makes
Bad Things happen. ;)

quoted

+of_phy_provider_register and devm_of_phy_provider_register macros can be used to
+register the phy_provider and it takes device and of_xlate as
+arguments. For the dt boot case, all PHY providers should use one of the above
+2 macros to register the PHY provider.
+
+void devm_of_phy_provider_unregister(struct device *dev,
+	struct phy_provider *phy_provider);
+void of_phy_provider_unregister(struct phy_provider *phy_provider);
+
+devm_of_phy_provider_unregister and of_phy_provider_unregister can be used to
+unregister the PHY.
+

[...]

quoted

diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
new file mode 100644
index 0000000..f1d15e5
--- /dev/null
+++ b/drivers/phy/phy-core.c

@@ -0,0 +1,714 @@

[...]

quoted

+static struct phy *phy_lookup(struct device *device, const char *port)
+{
+	unsigned int count;
+	struct phy *phy;
+	struct device *dev;
+	struct phy_consumer *consumers;
+	struct class_dev_iter iter;

	
Don't you need something like

	if (phy->init_data = NULL)	
		return ERR_PTR(-EINVAL);

to ensure there is no attempt to dereference NULL platform data ?

hmm.. perhaps a dev_WARN too..

quoted

+	class_dev_iter_init(&iter, phy_class, NULL, NULL);
+	while ((dev = class_dev_iter_next(&iter))) {
+		phy = to_phy(dev);
+		count = phy->init_data->num_consumers;
+		consumers = phy->init_data->consumers;
+		while (count--) {
+			if (!strcmp(consumers->dev_name, dev_name(device)) &&
+					!strcmp(consumers->port, port)) {
+				class_dev_iter_exit(&iter);
+				return phy;
+			}
+			consumers++;
+		}
+	}
+
+	class_dev_iter_exit(&iter);
+	return ERR_PTR(-ENODEV);
+}
+

[...]

quoted

+int phy_init(struct phy *phy)
+{
+	int ret;
+
+	ret = phy_pm_runtime_get_sync(phy);
+	if (ret < 0 && ret != -ENOTSUPP)
+		return ret;
+
+	mutex_lock(&phy->mutex);
+	if (phy->init_count++ = 0 && phy->ops->init) {
+		ret = phy->ops->init(phy);
+		if (ret < 0) {
+			dev_err(&phy->dev, "phy init failed --> %d\n", ret);
+			goto out;

Is this 'goto' and similar ones below really needed ?

That's just to signify an error path.. it doesn't affect anyways ;-)

Thanks
Kishon