From patchwork Fri Apr 21 13:15:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roger Quadros X-Patchwork-Id: 97903 Delivered-To: patch@linaro.org Received: by 10.140.109.52 with SMTP id k49csp321553qgf; Fri, 21 Apr 2017 06:17:07 -0700 (PDT) X-Received: by 10.84.173.67 with SMTP id o61mr16667376plb.46.1492780627620; Fri, 21 Apr 2017 06:17:07 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id b2si10345201pga.378.2017.04.21.06.17.07; Fri, 21 Apr 2017 06:17:07 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of netdev-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@ti.com; spf=pass (google.com: best guess record for domain of netdev-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=netdev-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=ti.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1039792AbdDUNQu (ORCPT + 6 others); Fri, 21 Apr 2017 09:16:50 -0400 Received: from fllnx209.ext.ti.com ([198.47.19.16]:31180 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1039793AbdDUNQp (ORCPT ); Fri, 21 Apr 2017 09:16:45 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by fllnx209.ext.ti.com (8.15.1/8.15.1) with ESMTP id v3LDFmZj022985; Fri, 21 Apr 2017 08:15:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ti.com; s=ti-com-17Q1; t=1492780548; bh=PZXVFw2BQfbH9JDUvXe/gF0GPxmQgyZ1vymB53kizFY=; h=Subject:To:References:CC:From:Date:In-Reply-To; b=akH7GAUGWZpg1rX9teK6C0EEy5kej5UxkgQ2/wWlT63nfqfUGir0BlwOy9r8mtcja roMdQ3LBXp2RZQ9+9jNHSWZfEv5u0vgS88bR+EkD0hE/Ijm91sc2yAua1JprRppXW0 SGoXjTOgXH50Jqt0gYteNxxDocC+CIKk46VDPwIw= Received: from DLEE70.ent.ti.com (dlee70.ent.ti.com [157.170.170.113]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id v3LDFgjT013814; Fri, 21 Apr 2017 08:15:42 -0500 Received: from dlep33.itg.ti.com (157.170.170.75) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.3.294.0; Fri, 21 Apr 2017 08:15:41 -0500 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id v3LDFdFg016205; Fri, 21 Apr 2017 08:15:39 -0500 Subject: [PATCH v4 net-next] mdio_bus: Issue GPIO RESET to PHYs. To: , Andrew Lunn , Florian Fainelli References: <1491381237-24635-1-git-send-email-rogerq@ti.com> <64d6494d-41d2-0faf-a434-057f796637fe@ti.com> CC: , , , , , , From: Roger Quadros Message-ID: Date: Fri, 21 Apr 2017 16:15:38 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Some boards [1] leave the PHYs at an invalid state during system power-up or reset thus causing unreliability issues with the PHY which manifests as PHY not being detected or link not functional. To fix this, these PHYs need to be RESET via a GPIO connected to the PHY's RESET pin. Some boards have a single GPIO controlling the PHY RESET pin of all PHYs on the bus whereas some others have separate GPIOs controlling individual PHY RESETs. In both cases, the RESET de-assertion cannot be done in the PHY driver as the PHY will not probe till its reset is de-asserted. So do the RESET de-assertion in the MDIO bus driver. [1] - am572x-idk, am571x-idk, a437x-idk Signed-off-by: Roger Quadros --- v4: - use dev_err() instead of pr_err() - put PHYs back in RESET on failure or mdiobus_unregister() - typo fixes uS -> us v3: - added more information in the DT binding document. v2: - add device tree binding document (mdio.txt) - specify default reset delay in of_mdio.c instead of mdio_bus.c Documentation/devicetree/bindings/net/mdio.txt | 33 ++++++++++++++++++ drivers/net/phy/mdio_bus.c | 47 ++++++++++++++++++++++++++ drivers/of/of_mdio.c | 7 ++++ include/linux/phy.h | 7 ++++ 4 files changed, 94 insertions(+) create mode 100644 Documentation/devicetree/bindings/net/mdio.txt -- 2.7.4 diff --git a/Documentation/devicetree/bindings/net/mdio.txt b/Documentation/devicetree/bindings/net/mdio.txt new file mode 100644 index 0000000..4ffbbac --- /dev/null +++ b/Documentation/devicetree/bindings/net/mdio.txt @@ -0,0 +1,33 @@ +Common MDIO bus properties. + +These are generic properties that can apply to any MDIO bus. + +Optional properties: +- reset-gpios: List of one or more GPIOs that control the RESET lines + of the PHYs on that MDIO bus. +- reset-delay-us: RESET pulse width in microseconds as per PHY datasheet. + +A list of child nodes, one per device on the bus is expected. These +should follow the generic phy.txt, or a device specific binding document. + +Example : +This example shows these optional properties, plus other properties +required for the TI Davinci MDIO driver. + + davinci_mdio: ethernet@0x5c030000 { + compatible = "ti,davinci_mdio"; + reg = <0x5c030000 0x1000>; + #address-cells = <1>; + #size-cells = <0>; + + reset-gpios = <&gpio2 5 GPIO_ACTIVE_LOW>; + reset-delay-us = <2>; /* PHY datasheet states 1us min */ + + ethphy0: ethernet-phy@1 { + reg = <1>; + }; + + ethphy1: ethernet-phy@3 { + reg = <3>; + }; + }; diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index fa7d51f..de927f7 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -22,8 +22,11 @@ #include #include #include +#include +#include #include #include +#include #include #include #include @@ -307,6 +310,7 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) { struct mdio_device *mdiodev; int i, err; + struct gpio_desc *gpiod; if (NULL == bus || NULL == bus->name || NULL == bus->read || NULL == bus->write) @@ -333,6 +337,35 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) if (bus->reset) bus->reset(bus); + /* de-assert bus level PHY GPIO resets */ + if (bus->num_reset_gpios > 0) { + bus->reset_gpiod = devm_kcalloc(&bus->dev, + bus->num_reset_gpios, + sizeof(struct gpio_desc *), + GFP_KERNEL); + if (!bus->reset_gpiod) + return -ENOMEM; + } + + for (i = 0; i < bus->num_reset_gpios; i++) { + gpiod = devm_gpiod_get_index(&bus->dev, "reset", i, + GPIOD_OUT_LOW); + if (IS_ERR(gpiod)) { + err = PTR_ERR(gpiod); + if (err != -ENOENT) { + dev_err(&bus->dev, + "mii_bus %s couldn't get reset GPIO\n", + bus->id); + return err; + } + } else { + bus->reset_gpiod[i] = gpiod; + gpiod_set_value_cansleep(gpiod, 1); + udelay(bus->reset_delay_us); + gpiod_set_value_cansleep(gpiod, 0); + } + } + for (i = 0; i < PHY_MAX_ADDR; i++) { if ((bus->phy_mask & (1 << i)) == 0) { struct phy_device *phydev; @@ -360,6 +393,13 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) mdiodev->device_remove(mdiodev); mdiodev->device_free(mdiodev); } + + /* Put PHYs in RESET to save power */ + for (i = 0; i < bus->num_reset_gpios; i++) { + if (bus->reset_gpiod[i]) + gpiod_set_value_cansleep(bus->reset_gpiod[i], 1); + } + device_del(&bus->dev); return err; } @@ -381,6 +421,13 @@ void mdiobus_unregister(struct mii_bus *bus) mdiodev->device_remove(mdiodev); mdiodev->device_free(mdiodev); } + + /* Put PHYs in RESET to save power */ + for (i = 0; i < bus->num_reset_gpios; i++) { + if (bus->reset_gpiod[i]) + gpiod_set_value_cansleep(bus->reset_gpiod[i], 1); + } + device_del(&bus->dev); } EXPORT_SYMBOL(mdiobus_unregister); diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c index 0b29798..7e4c80f 100644 --- a/drivers/of/of_mdio.c +++ b/drivers/of/of_mdio.c @@ -22,6 +22,8 @@ #include #include +#define DEFAULT_GPIO_RESET_DELAY 10 /* in microseconds */ + MODULE_AUTHOR("Grant Likely "); MODULE_LICENSE("GPL"); @@ -221,6 +223,11 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np) mdio->dev.of_node = np; + /* Get bus level PHY reset GPIO details */ + mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY; + of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us); + mdio->num_reset_gpios = of_gpio_named_count(np, "reset-gpios"); + /* Register the MDIO bus */ rc = mdiobus_register(mdio); if (rc) diff --git a/include/linux/phy.h b/include/linux/phy.h index 43a7748..8ce57f4 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -217,6 +217,13 @@ struct mii_bus { * matching its address */ int irq[PHY_MAX_ADDR]; + + /* GPIO reset pulse width in microseconds */ + int reset_delay_us; + /* Number of reset GPIOs */ + int num_reset_gpios; + /* Array of RESET GPIO descriptors */ + struct gpio_desc **reset_gpiod; }; #define to_mii_bus(d) container_of(d, struct mii_bus, dev)