From patchwork Fri Oct 23 10:56:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 11852731 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55516C388F9 for ; Fri, 23 Oct 2020 10:56:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B4C821D43 for ; Fri, 23 Oct 2020 10:56:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S462622AbgJWK45 (ORCPT ); Fri, 23 Oct 2020 06:56:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S462583AbgJWK4k (ORCPT ); Fri, 23 Oct 2020 06:56:40 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D4F6C0613CE for ; Fri, 23 Oct 2020 03:56:40 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kVukG-00087n-Kp; Fri, 23 Oct 2020 12:56:28 +0200 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1kVukF-0001k9-D5; Fri, 23 Oct 2020 12:56:27 +0200 From: Oleksij Rempel To: Andrew Lunn , "David S. Miller" , Florian Fainelli , Heiner Kallweit , Jakub Kicinski , Oliver Hartkopp Cc: Oleksij Rempel , David Jander , kernel@pengutronix.de, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Russell King , mkl@pengutronix.de, Marek Vasut , linux-can@vger.kernel.org Subject: [RFC PATCH v1 1/6] net: phy: add CAN PHY Virtual Bus Date: Fri, 23 Oct 2020 12:56:21 +0200 Message-Id: <20201023105626.6534-2-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201023105626.6534-1-o.rempel@pengutronix.de> References: <20201023105626.6534-1-o.rempel@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC Most of CAN PHYs (transceivers) are not attached to any data bus, so we are not able to communicate with them. For this case, we introduce a CAN specific virtual bus to make use of existing PHY framework. Signed-off-by: Oleksij Rempel --- drivers/net/phy/Kconfig | 8 ++ drivers/net/phy/Makefile | 1 + drivers/net/phy/can_phy_bus.c | 196 ++++++++++++++++++++++++++++++++++ include/linux/can/phy.h | 21 ++++ 4 files changed, 226 insertions(+) create mode 100644 drivers/net/phy/can_phy_bus.c create mode 100644 include/linux/can/phy.h diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig index 698bea312adc..39e3f57ea60a 100644 --- a/drivers/net/phy/Kconfig +++ b/drivers/net/phy/Kconfig @@ -153,6 +153,14 @@ config BCM_CYGNUS_PHY config BCM_NET_PHYLIB tristate +config CAN_PHY_BUS + tristate "Virtual CAN PHY Bus" + depends on PHYLIB + help + Most CAN PHYs (transceivers) are not attached to any data bus, so we + are not able to communicate with them. For this case, a CAN specific + virtual bus to make use of existing PHY framework. + config CICADA_PHY tristate "Cicada PHYs" help diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile index a13e402074cf..0d76d802c07f 100644 --- a/drivers/net/phy/Makefile +++ b/drivers/net/phy/Makefile @@ -47,6 +47,7 @@ obj-$(CONFIG_BCM87XX_PHY) += bcm87xx.o obj-$(CONFIG_BCM_CYGNUS_PHY) += bcm-cygnus.o obj-$(CONFIG_BCM_NET_PHYLIB) += bcm-phy-lib.o obj-$(CONFIG_BROADCOM_PHY) += broadcom.o +obj-$(CONFIG_CAN_PHY_BUS) += can_phy_bus.o obj-$(CONFIG_CICADA_PHY) += cicada.o obj-$(CONFIG_CORTINA_PHY) += cortina.o obj-$(CONFIG_DAVICOM_PHY) += davicom.o diff --git a/drivers/net/phy/can_phy_bus.c b/drivers/net/phy/can_phy_bus.c new file mode 100644 index 000000000000..b1712e19327c --- /dev/null +++ b/drivers/net/phy/can_phy_bus.c @@ -0,0 +1,196 @@ +// SPDX-License-Identifier: GPL-2.0-only +// SPDX-FileCopyrightText: 2020 Oleksij Rempel , Pengutronix + +#include +#include +#include +#include +#include +#include + +struct can_mdio_bus { + struct mii_bus *mii_bus; + struct list_head phys; +}; + +struct can_phy { + int addr; + struct phy_device *phydev; + struct list_head node; +}; + +static struct platform_device *pdev; +static struct can_mdio_bus platform_fmb = { + .phys = LIST_HEAD_INIT(platform_fmb.phys), +}; + +static DEFINE_IDA(phy_can_ida); + +/* The is the fake bus. All read/write operations are bugs. */ +static int can_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num) +{ + WARN_ON_ONCE(1); + return 0xFFFF; +} + +static int can_mdio_write(struct mii_bus *bus, int phy_addr, int reg_num, + u16 val) +{ + WARN_ON_ONCE(1); + return 0; +} + +static int can_phy_add(int phy_addr) +{ + struct can_mdio_bus *fmb = &platform_fmb; + struct can_phy *fp; + + fp = kzalloc(sizeof(*fp), GFP_KERNEL); + if (!fp) + return -ENOMEM; + + fp->addr = phy_addr; + + list_add_tail(&fp->node, &fmb->phys); + + return 0; +} + +static void can_phy_del(int phy_addr) +{ + struct can_mdio_bus *fmb = &platform_fmb; + struct can_phy *fp, *tmp; + + list_for_each_entry_safe(fp, tmp, &fmb->phys, node) { + if (fp->addr == phy_addr) { + list_del(&fp->node); + kfree(fp); + ida_simple_remove(&phy_can_ida, phy_addr); + return; + } + } +} + +struct phy_device *can_phy_register(struct device_node *mac_node) +{ + struct can_mdio_bus *fmb = &platform_fmb; + struct device_node *np; + struct phy_device *phy; + int phy_addr; + int ret; + + if (!fmb->mii_bus || fmb->mii_bus->state != MDIOBUS_REGISTERED) + return ERR_PTR(-EPROBE_DEFER); + + /* New binding */ + np = of_get_child_by_name(mac_node, "can-transceiver"); + if (!np) + return ERR_PTR(-ENODEV); + + /* Get the next available PHY address, up to PHY_MAX_ADDR */ + phy_addr = ida_simple_get(&phy_can_ida, 0, PHY_MAX_ADDR, GFP_KERNEL); + if (phy_addr < 0) { + err = ERR_PTR(phy_addr); + goto err_of_node_put; + } + + ret = can_phy_add(phy_addr); + if (ret < 0) + goto err_ida_simple_remove; + + phy = phy_device_create(fmb->mii_bus, phy_addr, 0, false, NULL); + if (IS_ERR(phy)) { + ret = ERR_PTR(phy); + goto err_can_phy_del; + } + + of_node_get(np); + phy->mdio.dev.of_node = np; + phy->is_pseudo_fixed_link = true; + + phy_advertise_supported(phy); + + ret = phy_device_register(phy); + if (ret) + goto err_phy_device_free; + + return phy; + +err_phy_device_free: + phy_device_free(phy); +err_can_phy_del: + can_phy_del(phy_addr); +err_ida_simple_remove: + ida_simple_remove(&phy_can_ida, phy_addr); +err_of_node_put: + of_node_put(np); + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(can_phy_register); + +void can_phy_unregister(struct phy_device *phy) +{ + phy_device_remove(phy); + of_node_put(phy->mdio.dev.of_node); + can_phy_del(phy->mdio.addr); +} +EXPORT_SYMBOL_GPL(can_phy_unregister); + +static int __init can_mdio_bus_init(void) +{ + struct can_mdio_bus *fmb = &platform_fmb; + int ret; + + pdev = platform_device_register_simple("Virtual CAN PHY Bus", 0, NULL, 0); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + fmb->mii_bus = mdiobus_alloc(); + if (fmb->mii_bus == NULL) { + ret = -ENOMEM; + goto err_mdiobus_reg; + } + + snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "virtual-can-0"); + fmb->mii_bus->name = "Virtual CAN PHY Bus"; + fmb->mii_bus->priv = fmb; + fmb->mii_bus->parent = &pdev->dev; + fmb->mii_bus->read = &can_mdio_read; + fmb->mii_bus->write = &can_mdio_write; + /* do not scan the bus for PHYs */ + fmb->mii_bus->phy_mask = ~0; + + ret = mdiobus_register(fmb->mii_bus); + if (ret) + goto err_mdiobus_alloc; + + return 0; + +err_mdiobus_alloc: + mdiobus_free(fmb->mii_bus); +err_mdiobus_reg: + platform_device_unregister(pdev); + return ret; +} +module_init(can_mdio_bus_init); + +static void __exit can_mdio_bus_exit(void) +{ + struct can_mdio_bus *fmb = &platform_fmb; + struct can_phy *fp, *tmp; + + mdiobus_unregister(fmb->mii_bus); + mdiobus_free(fmb->mii_bus); + platform_device_unregister(pdev); + + list_for_each_entry_safe(fp, tmp, &fmb->phys, node) { + list_del(&fp->node); + kfree(fp); + } + ida_destroy(&phy_can_ida); +} +module_exit(can_mdio_bus_exit); + +MODULE_DESCRIPTION("Virtual CAN PHY Bus"); +MODULE_AUTHOR("Oleksij Rempel"); +MODULE_LICENSE("GPLv2"); diff --git a/include/linux/can/phy.h b/include/linux/can/phy.h new file mode 100644 index 000000000000..3772132d9100 --- /dev/null +++ b/include/linux/can/phy.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __CAN_PHY_H +#define __CAN_PHY_H + +#include + +#if IS_ENABLED(CONFIG_CAN_PHY) +extern void can_phy_unregister(struct phy_device *phydev); +struct phy_device *can_phy_register(struct device_node *mac_node); +#else +static inline struct phy_device *can_phy_register(struct device_node *mac_node) +{ + return ERR_PTR(-ENODEV); +} + +static inline void can_phy_unregister(struct phy_device *phydev) +{ +} +#endif /* CONFIG_CAN_PHY */ + +#endif /* __CAN_PHY_H */