From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752179AbaENTSZ (ORCPT ); Wed, 14 May 2014 15:18:25 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:35989 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751689AbaENTSV (ORCPT ); Wed, 14 May 2014 15:18:21 -0400 X-AuditID: cbfee68f-b7eff6d000002b70-a3-5373c17b943c From: Rahul Sharma To: linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: a.hajda@samsung.com, t.stanislaws@samsung.com, devicetree@vger.kernel.org, kgene.kim@samsung.com, kishon@ti.com, kyungmin.park@samsung.com, robh+dt@kernel.org, grant.likely@linaro.org, sylvester.nawrocki@gmail.com, joshi@samsung.com, Rahul Sharma Subject: [PATCH v3 0/3] phy: Add exynos-simple-phy driver Date: Thu, 15 May 2014 00:47:20 +0530 Message-id: <1400095043-685-1-git-send-email-rahul.sharma@samsung.com> X-Mailer: git-send-email 1.7.9.5 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupmkeLIzCtJLcpLzFFi42JZI2JSp1t9sDjYoP0Cv8WtdedYLeYfARJX vr5nszjwZwejxfddX9gtehdcZbO48LSHzeJs0xt2i8u75rBZzDi/j8liyqLDrBate4+wW8z7 vJPJYl77S1YHPo+ds+6ye2xa1cnmcefaHjaP+93HmTz6tqxi9Dh+YzuTx+dNcgHsUVw2Kak5 mWWpRfp2CVwZB36vYSn4IFWxYMsH9gbG2aJdjJwcEgImEqtubmKCsMUkLtxbz9bFyMUhJLCU UWLy3WvMXYwcYEVX3sZDxKczSmz9e5AFwmlnkmjt3MoK0s0moCsx++AzRhBbRCBN4tuBFlaQ ImaB2UwSG1+8ZgNJCAtYSnyb95QZxGYRUJVYNGklC4jNK+AmsfhSA9Q2BYk5k2xAeiUEjrFL /DjWzQRRLyDxbfIhFogaWYlNB5ghrpaUOLjiBssERsEFjAyrGEVTC5ILipPSi4z1ihNzi0vz 0vWS83M3MQIj4vS/Z/07GO8esD7EmAw0biKzlGhyPjCi8kriDY3NjCxMTUyNjcwtzUgTVhLn vf8wKUhIID2xJDU7NbUgtSi+qDQntfgQIxMHp1QDI9ebqflHd5szBr94YrNt1fFM3iOCUQ7d BlHv/+/5FFyxUJy7oMtwrZP1Do5Db+Ltf71eJ6Z33eixygGfR5VpxtaPIjpMvcsVdIzOqGQV Xas6K/KHd/HbtI/pn6Yf2hVlXz9L9MybZTsaXbdVrn6+b/ZFpyuaqmEmG7TvrXm4r3GtebvX uyfrMpRYijMSDbWYi4oTARsQ+deeAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrBIsWRmVeSWpSXmKPExsVy+t9jQd3qg8XBBv8eMFncWneO1WL+ESBx 5et7NosDf3YwWnzf9YXdonfBVTaLC0972CzONr1ht7i8aw6bxYzz+5gspiw6zGrRuvcIu8W8 zzuZLOa1v2R14PPYOesuu8emVZ1sHneu7WHzuN99nMmjb8sqRo/jN7YzeXzeJBfAHtXAaJOR mpiSWqSQmpecn5KZl26r5B0c7xxvamZgqGtoaWGupJCXmJtqq+TiE6DrlpkDdLSSQlliTilQ KCCxuFhJ3w7ThNAQN10LmMYIXd+QILgeIwM0kLCGMePA7zUsBR+kKhZs+cDewDhbtIuRg0NC wETiytv4LkZOIFNM4sK99WxdjFwcQgLTGSW2/j3IAuG0M0m0dm5lBaliE9CVmH3wGSOILSKQ JvHtQAsrSBGzwGwmiY0vXrOBJIQFLCW+zXvKDGKzCKhKLJq0kgXE5hVwk1h8qYEZYrOCxJxJ NhMYuRcwMqxiFE0tSC4oTkrPNdQrTswtLs1L10vOz93ECI63Z1I7GFc2WBxiFOBgVOLhZZhc HCzEmlhWXJl7iFGCg1lJhDdpL1CINyWxsiq1KD++qDQntfgQYzLQ8onMUqLJ+cBUkFcSb2hs Ym5qbGppYmFiZkmasJI474FW60AhgfTEktTs1NSC1CKYLUwcnFINjIwcfI+56l4Kxetmxhza FWWRysYUcjPOZTrL9u+S7NNNK1pfTwr1mqV2qvowe5nfqzk++x3c+7Vm7pBufRQjUdZUWnTI u6pRZj6fqIJhenevME/mz9mdW8/7/AsReuRfct9tn4SP+DH3ySxMLwJXrDj5StXHviGnauVh 4cbuhe9XTNcMlrimxFKckWioxVxUnAgASWFOfPsCAAA= DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rahul Sharma Hi All, This series has been originally proposed by Tomasz Stanislawski. With his permission, I have addressed the following review comments in V3. Changelog: v3: * Implement lazy-init of PHYs. * Use MACROs instead of numbers to represent phys. * Use regmap interface to access PMU registers. It is based on "Next" branch in Kishon Vijay Abraham's tree at https://git.kernel.org/cgit/linux/kernel/git/kishon/linux-phy.git/ /* Original Message from Tomasz Stanislawski */ The Samsung SoCs from Exynos family are enhanced with a bunch of devices that provide functionality of a physical layer for interfaces like USB, HDMI, SATA, etc. They are controlled by a simple interface, often a single bit that enables and/or resets the physical layer. An IP driver should to control such a controller in an abstract manner. Therefore, such 'enablers' were implemented as clocks in older versions of Linux kernel. With the dawn of PHY subsystems, PHYs become a natural way of exporting the 'enabler' functionality to drivers. However, there is an unexpected consequence. Some of those 1-bit PHYs were implemented as separate drivers. This means that one has to create a struct device, struct phy, its phy provider and 100-150 lines of driver code to basically set one bit. The DP phy driver is a good example: https://lkml.org/lkml/2013/7/18/53 And simple-phy RFC (shares only driver code but not other resources): https://lkml.org/lkml/2013/10/21/313 To avoid waste of resources I propose to create all such 1-bit phys from Exynos SoC using a single device, driver and phy provider. This patchset contains a proposed solution. All comment are welcome. Hopefully in future the functionality introduced by this patch may be merged into a larger Power Management Unit (PMU) gluer driver. On Samsusng SoC , the PMU part contains a number of register barely linked to power management (like clock gating, clock dividers, CPU resetting, etc.). It may be tempting to create a hybrid driver that export clocks/phys/etc that are controlled by PMU unit. Alternative solutions might be: * exporting a regmap to the IP driver and allow the driver to control the PHY layer like in the patch: http://thread.gmane.org/gmane.linux.kernel.samsung-soc/28617/focus=28648 * create a dedicated power domain for hdmiphy Regards, Tomasz Stanislawski v2: * rename to exynos-simple-phy * fix usage of devm_ioremap() * add documentation for DT bindings * add patches to client drivers v1: initial version Tomasz Stanislawski (3): phy: Add exynos-simple-phy driver drm: exynos: hdmi: use hdmiphy as PHY s5p-tv: hdmi: use hdmiphy as PHY .../devicetree/bindings/phy/samsung-phy.txt | 56 ++++++ drivers/gpu/drm/exynos/exynos_hdmi.c | 11 +- drivers/media/platform/s5p-tv/hdmi_drv.c | 11 +- drivers/phy/Kconfig | 5 + drivers/phy/Makefile | 1 + drivers/phy/exynos-simple-phy.c | 189 ++++++++++++++++++++ include/dt-bindings/phy/exynos-simple-phy.h | 27 +++ 7 files changed, 290 insertions(+), 10 deletions(-) create mode 100644 drivers/phy/exynos-simple-phy.c create mode 100644 include/dt-bindings/phy/exynos-simple-phy.h -- 1.7.9.5