Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757299Ab3G3FM7 (ORCPT ); Tue, 30 Jul 2013 01:12:59 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:50478 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754118Ab3G3FMz (ORCPT ); Tue, 30 Jul 2013 01:12:55 -0400 Message-ID: <51F74B20.6070005@ti.com> Date: Tue, 30 Jul 2013 10:42:00 +0530 From: Kishon Vijay Abraham I User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Sylwester Nawrocki CC: , , , , , , , , , , , , , , , , Tomasz Figa , , , , , , , , , , Subject: Re: [RESEND PATCH v10 1/8] drivers: phy: add generic PHY framework References: <1374842963-13545-1-git-send-email-kishon@ti.com> <1374842963-13545-2-git-send-email-kishon@ti.com> <51F68F73.9060603@samsung.com> In-Reply-To: <51F68F73.9060603@samsung.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6866 Lines: 176 Hi, On Monday 29 July 2013 09:21 PM, Sylwester Nawrocki wrote: > On 07/26/2013 02:49 PM, Kishon Vijay Abraham I wrote: >> 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 >> Cc: Greg Kroah-Hartman >> Signed-off-by: Kishon Vijay Abraham I >> Acked-by: Felipe Balbi >> Tested-by: Sylwester Nawrocki >> --- >> .../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 > [...] >> @@ -0,0 +1,166 @@ >> + PHY SUBSYSTEM >> + Kishon Vijay Abraham I >> + >> +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. ;) > >> +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. >> + > [...] >> 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 @@ > [...] >> +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.. > >> + 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); >> +} >> + > [...] >> +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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/