From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 D6DE1C43441 for ; Wed, 21 Nov 2018 15:08:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 899EE21479 for ; Wed, 21 Nov 2018 15:08:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Xp1Nqg3i" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 899EE21479 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731370AbeKVBmt (ORCPT ); Wed, 21 Nov 2018 20:42:49 -0500 Received: from mail-io1-f67.google.com ([209.85.166.67]:38609 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731181AbeKVBmK (ORCPT ); Wed, 21 Nov 2018 20:42:10 -0500 Received: by mail-io1-f67.google.com with SMTP id l14so4121750ioj.5; Wed, 21 Nov 2018 07:07:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=bcpE3J0kqLJApsi7Xb6FjcYI/Yg61+lMr9IEjxkjor8=; b=Xp1Nqg3iuVOBIQ9AWSbGmQObHVUuiYRy9bDr1ECHWuwAU/eJTB4cPrRSnfmnrGEoBo j0M6M0kwbM/6RJwb4r3CGll1vSjSh51yKLw8a0rEnr0PzCSoMykShhK4wI9PWJ5DwLZd D9Yv+qa/yZO0ytiSNtdsk/SjTNexVsiSLemQxQx8Wu7Z653Ew3OxbbBkGCmuRCtyCgS0 Pl0kSHltGQvXBj4O90C/JEM10T2PwFm7Fe3JaZVnnSpoo1jLQBDkELERkd4hRBdjDP6s WU3I8+slnuKd4ZAg5J2q4AsE1eawTuuUqKPiw5R0P/Fijk8DHxcgulJn/IvpjClLn19+ QPyA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=bcpE3J0kqLJApsi7Xb6FjcYI/Yg61+lMr9IEjxkjor8=; b=fZSrxOJ80IczUYGDXLlTp2YGUYEpiC/jfiAwGbkiZCNTLlSv1efm7/DXG1kpcyY/t/ ySLPPU1EhyGueUWyf+uz102c74Bvt2DguoJ3UOaQqg6aBCndKAVhaSOKvF2pkNebSKtt pq8ae/Lmkle2qcFpVe9O0UegKqSUL6lqqgmJSalnOMPL/qk523ad0XBQgUy1MTfhoMzL WBOm54x2tAd+/q0/PT1TCglzv3LwZdbmkd2/6wW5M5vm0m54FLYl4uhPf/mQZxgnP4VV aTEOC14UTwA8XZmuV++ePp978rk5WrIZgvMtFa3JlWuh6Z3zhsRliVq1xZjUyR3pC3NT bmTA== X-Gm-Message-State: AA+aEWZquCYpUH9d8XPSFlm3VA+3hVFUa5avfxWNuoXSsLoyZzvDEz/b vG/G4Bbzt1CWsd8D2uYg58o= X-Google-Smtp-Source: AFSGD/XmNuoGNlmGU9tHh0dyCzbYKGnIArxXxwTP1A2myGCMTO5sPgFPexbfJMWAsxpaGz0+6WlxPw== X-Received: by 2002:a6b:7a46:: with SMTP id k6mr5348232iop.60.1542812840527; Wed, 21 Nov 2018 07:07:20 -0800 (PST) Received: from svens-asus.arcx.com ([184.94.50.30]) by smtp.gmail.com with ESMTPSA id c3sm5113119ioi.2.2018.11.21.07.07.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Nov 2018 07:07:19 -0800 (PST) From: thesven73@gmail.com X-Google-Original-From: TheSven73@googlemail.com To: svendev@arcx.com, robh+dt@kernel.org, linus.walleij@linaro.org Cc: lee.jones@linaro.org, mark.rutland@arm.com, afaerber@suse.de, treding@nvidia.com, david@lechnology.com, noralf@tronnes.org, johan@kernel.org, monstr@monstr.eu, michal.vokac@ysoft.com, arnd@arndb.de, gregkh@linuxfoundation.org, john.garry@huawei.com, geert+renesas@glider.be, robin.murphy@arm.com, paul.gortmaker@windriver.com, sebastien.bourdelin@savoirfairelinux.com, icenowy@aosc.io, stuyoder@gmail.com, maxime.ripard@bootlin.com, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: [PATCH anybus v4 2/7] fieldbus: support the Arcx anybus bridge Date: Wed, 21 Nov 2018 10:07:04 -0500 Message-Id: <20181121150709.6030-3-TheSven73@googlemail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181121150709.6030-1-TheSven73@googlemail.com> References: <20181121150709.6030-1-TheSven73@googlemail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a driver for the Arcx anybus bridge. This chip embeds up to two Anybus-S application connectors (slots), and connects to the SoC via a parallel memory bus. There is also a CAN power readout, unrelated to the Anybus, modelled as a regulator. Signed-off-by: Sven Van Asbroeck --- drivers/fieldbus/Kconfig | 10 + drivers/fieldbus/Makefile | 1 + drivers/fieldbus/anybus-bridge.c | 321 +++++++++++++++++++++++++++++++ 3 files changed, 332 insertions(+) create mode 100644 drivers/fieldbus/anybus-bridge.c diff --git a/drivers/fieldbus/Kconfig b/drivers/fieldbus/Kconfig index 1d1929ba7e27..fc2e20b59b38 100644 --- a/drivers/fieldbus/Kconfig +++ b/drivers/fieldbus/Kconfig @@ -16,4 +16,14 @@ menuconfig FIELDBUS_DEV if FIELDBUS_DEV +config ARCX_ANYBUS_BRIDGE + tristate "Arcx Anybus-S Bridge" + depends on OF && GPIOLIB + help + Select this to get support for the Arcx Anybus bridge. + It connects to the SoC via a parallel memory bus, and + embeds up to two Anybus-S application connectors (slots). + There is also a CAN power readout, unrelated to the Anybus, + modelled as a regulator. + endif diff --git a/drivers/fieldbus/Makefile b/drivers/fieldbus/Makefile index 768a116fc9c6..a623722aace6 100644 --- a/drivers/fieldbus/Makefile +++ b/drivers/fieldbus/Makefile @@ -7,3 +7,4 @@ obj-$(CONFIG_FIELDBUS_DEV) += fieldbus_dev_core.o fieldbus_dev_core-y := dev_core.o # Devices +obj-$(CONFIG_ARCX_ANYBUS_BRIDGE) += anybus-bridge.o diff --git a/drivers/fieldbus/anybus-bridge.c b/drivers/fieldbus/anybus-bridge.c new file mode 100644 index 000000000000..9eee39efc3aa --- /dev/null +++ b/drivers/fieldbus/anybus-bridge.c @@ -0,0 +1,321 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Arcx Anybus Bridge driver + * + * Copyright (C) 2018 Arcx Inc + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define CPLD_STATUS1 0x80 +#define CPLD_CONTROL 0x80 +#define CPLD_CONTROL_CRST 0x40 +#define CPLD_CONTROL_RST1 0x04 +#define CPLD_CONTROL_RST2 0x80 +#define CPLD_STATUS1_AB 0x02 +#define CPLD_STATUS1_CAN_POWER 0x01 +#define CPLD_DESIGN_LO 0x81 +#define CPLD_DESIGN_HI 0x82 +#define CPLD_CAP 0x83 +#define CPLD_CAP_COMPAT 0x01 +#define CPLD_CAP_SEP_RESETS 0x02 + +struct bridge_priv { + struct device *class_dev; + struct reset_controller_dev rcdev; + bool common_reset; + struct gpio_desc *reset_gpiod; + void __iomem *cpld_base; + spinlock_t regs_lock; + u8 control_reg; + char version[3]; + u16 design_no; +}; + +static void do_reset(struct bridge_priv *cd, u8 rst_bit, bool reset) +{ + unsigned long flags; + + spin_lock_irqsave(&cd->regs_lock, flags); + /* + * CPLD_CONTROL is write-only, so cache its value in + * cd->control_reg + */ + if (reset) + cd->control_reg &= ~rst_bit; + else + cd->control_reg |= rst_bit; + writeb(cd->control_reg, cd->cpld_base + CPLD_CONTROL); + /* + * h/w work-around: + * the hardware is 'too fast', so a reset followed by an immediate + * not-reset will _not_ change the anybus reset line in any way, + * losing the reset. to prevent this from happening, introduce + * a minimum reset duration. + * Verified minimum safe duration required using a scope + * on 14-June-2018: 100 us. + */ + if (reset) + udelay(100); + spin_unlock_irqrestore(&cd->regs_lock, flags); +} + +static int anybuss_reset(struct bridge_priv *cd, + unsigned long id, bool reset) +{ + if (id >= 2) + return -EINVAL; + if (cd->common_reset) + do_reset(cd, CPLD_CONTROL_CRST, reset); + else + do_reset(cd, id ? CPLD_CONTROL_RST2 : CPLD_CONTROL_RST1, reset); + return 0; +} + +static int anybuss_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct bridge_priv *cd = container_of(rcdev, struct bridge_priv, rcdev); + + return anybuss_reset(cd, id, true); +} + +static int anybuss_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct bridge_priv *cd = container_of(rcdev, struct bridge_priv, rcdev); + + return anybuss_reset(cd, id, false); +} + +static const struct reset_control_ops anybuss_reset_ops = { + .assert = anybuss_reset_assert, + .deassert = anybuss_reset_deassert, +}; + +static ssize_t version_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct bridge_priv *cd = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", cd->version); +} +static DEVICE_ATTR_RO(version); + +static ssize_t design_number_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct bridge_priv *cd = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", cd->design_no); +} +static DEVICE_ATTR_RO(design_number); + +static struct attribute *bridge_attributes[] = { + &dev_attr_version.attr, + &dev_attr_design_number.attr, + NULL, +}; + +static struct attribute_group bridge_attribute_group = { + .attrs = bridge_attributes, +}; + +static const struct attribute_group *bridge_attribute_groups[] = { + &bridge_attribute_group, + NULL, +}; + +static void bridge_device_release(struct device *dev) +{ + kfree(dev); +} + +static int can_power_is_enabled(struct regulator_dev *rdev) +{ + struct bridge_priv *cd = rdev_get_drvdata(rdev); + + return !(readb(cd->cpld_base + CPLD_STATUS1) & CPLD_STATUS1_CAN_POWER); +} + +static struct regulator_ops can_power_ops = { + .is_enabled = can_power_is_enabled, +}; + +static const struct regulator_desc can_power_desc = { + .name = "regulator-can-power", + .id = -1, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .ops = &can_power_ops, +}; + +static struct class *bridge_class; +static DEFINE_IDA(bridge_index_ida); + +static int bridge_probe(struct platform_device *pdev) +{ + struct bridge_priv *cd; + struct device *dev = &pdev->dev; + struct regulator_config config = { }; + struct regulator_dev *regulator; + int err, id; + struct resource *res; + u8 status1, cap; + + cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL); + if (!cd) + return -ENOMEM; + dev_set_drvdata(dev, cd); + spin_lock_init(&cd->regs_lock); + cd->reset_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(cd->reset_gpiod)) + return PTR_ERR(cd->reset_gpiod); + + /* CPLD control memory, sits at index 0 */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + cd->cpld_base = devm_ioremap_resource(dev, res); + if (IS_ERR(cd->cpld_base)) { + dev_err(dev, + "failed to map cpld base address\n"); + err = PTR_ERR(cd->cpld_base); + goto out_reset; + } + + /* identify cpld */ + status1 = readb(cd->cpld_base + CPLD_STATUS1); + cd->design_no = (readb(cd->cpld_base + CPLD_DESIGN_HI) << 8) | + readb(cd->cpld_base + CPLD_DESIGN_LO); + snprintf(cd->version, sizeof(cd->version), "%c%d", + 'A' + ((status1>>5) & 0x7), + (status1>>2) & 0x7); + dev_info(dev, "Bridge is design number %d, revision %s\n", + cd->design_no, + cd->version); + cap = readb(cd->cpld_base + CPLD_CAP); + if (!(cap & CPLD_CAP_COMPAT)) { + dev_err(dev, "unsupported bridge [cap=0x%02X]", cap); + err = -ENODEV; + goto out_reset; + } + + if (status1 & CPLD_STATUS1_AB) { + dev_info(dev, "Bridge has anybus-S slot(s)"); + cd->common_reset = !(cap & CPLD_CAP_SEP_RESETS); + dev_info(dev, "Bridge supports %s", cd->common_reset ? + "a common reset" : "separate resets"); + cd->rcdev.owner = THIS_MODULE; + cd->rcdev.nr_resets = 2; + cd->rcdev.ops = &anybuss_reset_ops; + cd->rcdev.of_node = dev->of_node; + err = devm_reset_controller_register(dev, &cd->rcdev); + if (err) + goto out_reset; + } + + id = ida_simple_get(&bridge_index_ida, 0, 0, GFP_KERNEL); + if (id < 0) { + err = id; + goto out_reset; + } + /* export can power readout as a regulator */ + config.dev = dev; + config.driver_data = cd; + regulator = devm_regulator_register(dev, &can_power_desc, &config); + if (IS_ERR(regulator)) { + err = PTR_ERR(regulator); + goto out_reset; + } + /* make bridge info visible to userspace */ + cd->class_dev = kzalloc(sizeof(*cd->class_dev), GFP_KERNEL); + if (!cd->class_dev) { + err = -ENOMEM; + goto out_ida; + } + cd->class_dev->class = bridge_class; + cd->class_dev->groups = bridge_attribute_groups; + cd->class_dev->parent = dev; + cd->class_dev->id = id; + cd->class_dev->release = bridge_device_release; + dev_set_name(cd->class_dev, "bridge%d", cd->class_dev->id); + dev_set_drvdata(cd->class_dev, cd); + err = device_register(cd->class_dev); + if (err) + goto out_dev; + return 0; +out_dev: + put_device(cd->class_dev); +out_ida: + ida_simple_remove(&bridge_index_ida, id); +out_reset: + gpiod_set_value_cansleep(cd->reset_gpiod, 1); + return err; +} + +static int bridge_remove(struct platform_device *pdev) +{ + struct bridge_priv *cd = platform_get_drvdata(pdev); + int id = cd->class_dev->id; + + device_unregister(cd->class_dev); + ida_simple_remove(&bridge_index_ida, id); + gpiod_set_value_cansleep(cd->reset_gpiod, 1); + return 0; +} + +static const struct of_device_id bridge_of_match[] = { + { .compatible = "arcx,anybus-bridge" }, + { } +}; + +MODULE_DEVICE_TABLE(of, bridge_of_match); + +static struct platform_driver bridge_driver = { + .probe = bridge_probe, + .remove = bridge_remove, + .driver = { + .name = "arcx-anybus-bridge", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(bridge_of_match), + }, +}; + +static int __init bridge_init(void) +{ + int err; + + bridge_class = class_create(THIS_MODULE, "arcx_anybus_bridge"); + if (!IS_ERR(bridge_class)) { + err = platform_driver_register(&bridge_driver); + if (err) + class_destroy(bridge_class); + } else + err = PTR_ERR(bridge_class); + return err; +} + +static void __exit bridge_exit(void) +{ + platform_driver_unregister(&bridge_driver); + class_destroy(bridge_class); +} + +module_init(bridge_init); +module_exit(bridge_exit); + +MODULE_DESCRIPTION("Arcx Anybus Bridge driver"); +MODULE_AUTHOR("Sven Van Asbroeck "); +MODULE_LICENSE("GPL v2"); -- 2.17.1