From patchwork Tue Jan 2 14:42:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 123148 Delivered-To: patch@linaro.org Received: by 10.140.22.227 with SMTP id 90csp9046450qgn; Tue, 2 Jan 2018 06:48:18 -0800 (PST) X-Google-Smtp-Source: ACJfBouL7XFTTBALLFQzAvvBWZZQrPE5EPSJAEsTE57oq9+9eUyJ8N//wx+GHhkaz3wZWQ3CoSmt X-Received: by 10.99.174.67 with SMTP id e3mr8652386pgp.224.1514904497955; Tue, 02 Jan 2018 06:48:17 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1514904497; cv=none; d=google.com; s=arc-20160816; b=P/NqN0dPOxf0D5fIRNUnQbUvGFB54wzCIj174cP+gyIOL3/OR9AD0U8xDSAEysyshB ILHuA3P68TJreNvNQLgmqSgmAHRForA+T62xJauG6QiukrQmSP/kRI9+QCuLCuTPgc08 g/2QEC2StvJPKP2IlQsLIVF8Bjk7c4opcM/i0lw8gb+hQ+eOfNqhl6xuXHRw46QJk8f1 OLcP3MbrDI0QT7CboBm4WMOnUoCJXDVwLLXOxXTXr2nzM3Kjkoe7t4TFUCQxby0ie6tt K3SXlZfg5XD6Luwss6tQEPh/gHygptBDkCm8vkeljw6ygdok1ZH5m+GAYJMN198roqyh mrww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=wNoT+boEXbZNwo86Pa2Ej/Rjo74JQhNfHIpVo2jUD48=; b=M3jqd2TJJFq0QDvxfFUUy4aOBaDT2DOyVyfrgUSGXfBeN0oYTx3FBKYYgoaJmvP15t gXEcFWPa+/QQPYwNeIn0a1pL1GZB3HST1YP6nZIyHfsC3/h7QHyN2/WcrIqS/kJvvEXA 3tyP5LsmfiOGtM9vE1Ay0WP1Oqkazz4ZoB6AfyLF85mdstVz9oerSPd2urmIhyF9kV1y hE8rxnK0dUeXVpB7ngIRPKgIDzNuVbSlZxEyhYkXx1HxcxiFAXrDjPVmCCUQvPXBLrOU 8mbXGRJOhmlQBYgFoc71d8kBVuxyW8KGt+pvjL8vhD8ZH9iS5V9FvR+DyLFPTIvvMjnG ySxw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=devicetree-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id t12si32080683plm.469.2018.01.02.06.48.17; Tue, 02 Jan 2018 06:48:17 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=devicetree-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751602AbeABOsQ (ORCPT + 6 others); Tue, 2 Jan 2018 09:48:16 -0500 Received: from foss.arm.com ([217.140.101.70]:39656 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753201AbeABOnJ (ORCPT ); Tue, 2 Jan 2018 09:43:09 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 64AA41650; Tue, 2 Jan 2018 06:43:09 -0800 (PST) Received: from e107155-lin.cambridge.arm.com (e107155-lin.cambridge.arm.com [10.1.210.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 522303F25C; Tue, 2 Jan 2018 06:43:07 -0800 (PST) From: Sudeep Holla To: ALKML , LKML , DTML Cc: Sudeep Holla , Roy Franz , Harb Abdulhamid , Nishanth Menon , Arnd Bergmann , Loc Ho , Alexey Klimov , Ryan Harkin , Jassi Brar Subject: [PATCH v5 05/20] firmware: arm_scmi: add scmi protocol bus to enumerate protocol devices Date: Tue, 2 Jan 2018 14:42:27 +0000 Message-Id: <1514904162-11201-6-git-send-email-sudeep.holla@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1514904162-11201-1-git-send-email-sudeep.holla@arm.com> References: <1514904162-11201-1-git-send-email-sudeep.holla@arm.com> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org The SCMI specification encompasses various protocols. However, not every protocol has to be present on a given platform/implementation as not every protocol is relevant for it. Furthermore, the platform chooses which protocols it exposes to a given agent. The only protocol that must be implemented is the base protocol. The base protocol is used by an agent to discover which protocols are available to it. In order to enumerate the discovered implemented protocols, this patch adds support for a separate scmi protocol bus. It also adds mechanism to register support for different protocols. Cc: Arnd Bergmann Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/Makefile | 3 +- drivers/firmware/arm_scmi/bus.c | 232 +++++++++++++++++++++++++++++++++++++ drivers/firmware/arm_scmi/common.h | 1 + include/linux/scmi_protocol.h | 62 ++++++++++ 4 files changed, 297 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/arm_scmi/bus.c -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile index 5d9c7ef35f0f..5f4ec2613db6 100644 --- a/drivers/firmware/arm_scmi/Makefile +++ b/drivers/firmware/arm_scmi/Makefile @@ -1,3 +1,4 @@ -obj-y = scmi-driver.o scmi-protocols.o +obj-y = scmi-bus.o scmi-driver.o scmi-protocols.o +scmi-bus-y = bus.o scmi-driver-y = driver.o scmi-protocols-y = base.o diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c new file mode 100644 index 000000000000..cf1c2464cb0f --- /dev/null +++ b/drivers/firmware/arm_scmi/bus.c @@ -0,0 +1,232 @@ +/* + * System Control and Management Interface (SCMI) Message Protocol bus layer + * + * Copyright (C) 2017 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along + * with this program. If not, see . + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include + +#include "common.h" + +static DEFINE_IDA(scmi_bus_id); +static DEFINE_IDR(scmi_protocols); +static DEFINE_SPINLOCK(protocol_lock); + +static const struct scmi_device_id * +scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv) +{ + const struct scmi_device_id *id = scmi_drv->id_table; + + if (!id) + return NULL; + + for (; id->protocol_id; id++) + if (id->protocol_id == scmi_dev->protocol_id) + return id; + + return NULL; +} + +static int scmi_dev_match(struct device *dev, struct device_driver *drv) +{ + struct scmi_driver *scmi_drv = to_scmi_driver(drv); + struct scmi_device *scmi_dev = to_scmi_dev(dev); + const struct scmi_device_id *id; + + id = scmi_dev_match_id(scmi_dev, scmi_drv); + if (id) + return 1; + + return 0; +} + +static int scmi_protocol_init(int protocol_id, struct scmi_handle *handle) +{ + scmi_prot_init_fn_t fn = idr_find(&scmi_protocols, protocol_id); + + if (unlikely(!fn)) + return -EINVAL; + return fn(handle); +} + +static int scmi_dev_probe(struct device *dev) +{ + struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver); + struct scmi_device *scmi_dev = to_scmi_dev(dev); + const struct scmi_device_id *id; + int ret; + + id = scmi_dev_match_id(scmi_dev, scmi_drv); + if (!id) + return -ENODEV; + + if (!scmi_dev->handle) + return -EPROBE_DEFER; + + ret = scmi_protocol_init(scmi_dev->protocol_id, scmi_dev->handle); + if (ret) + return ret; + + return scmi_drv->probe(scmi_dev); +} + +static int scmi_dev_remove(struct device *dev) +{ + struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver); + struct scmi_device *scmi_dev = to_scmi_dev(dev); + + if (scmi_drv->remove) + scmi_drv->remove(scmi_dev); + + return 0; +} + +static struct bus_type scmi_bus_type = { + .name = "scmi_protocol", + .match = scmi_dev_match, + .probe = scmi_dev_probe, + .remove = scmi_dev_remove, +}; + +int scmi_driver_register(struct scmi_driver *driver, struct module *owner, + const char *mod_name) +{ + int retval; + + driver->driver.bus = &scmi_bus_type; + driver->driver.name = driver->name; + driver->driver.owner = owner; + driver->driver.mod_name = mod_name; + + retval = driver_register(&driver->driver); + if (!retval) + pr_debug("registered new scmi driver %s\n", driver->name); + + return retval; +} +EXPORT_SYMBOL_GPL(scmi_driver_register); + +void scmi_driver_unregister(struct scmi_driver *driver) +{ + driver_unregister(&driver->driver); +} +EXPORT_SYMBOL_GPL(scmi_driver_unregister); + +struct scmi_device * +scmi_device_create(struct device_node *np, struct device *parent, int protocol) +{ + int id, retval; + struct scmi_device *scmi_dev; + + id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL); + if (id < 0) + return NULL; + + scmi_dev = kzalloc(sizeof(*scmi_dev), GFP_KERNEL); + if (!scmi_dev) + goto no_mem; + + scmi_dev->id = id; + scmi_dev->protocol_id = protocol; + scmi_dev->dev.parent = parent; + scmi_dev->dev.of_node = np; + scmi_dev->dev.bus = &scmi_bus_type; + dev_set_name(&scmi_dev->dev, "scmi_dev.%d", id); + + retval = device_register(&scmi_dev->dev); + if (!retval) + return scmi_dev; + + put_device(&scmi_dev->dev); + kfree(scmi_dev); +no_mem: + ida_simple_remove(&scmi_bus_id, id); + return NULL; +} + +void scmi_device_destroy(struct scmi_device *scmi_dev) +{ + scmi_handle_put(scmi_dev->handle); + device_unregister(&scmi_dev->dev); + ida_simple_remove(&scmi_bus_id, scmi_dev->id); + kfree(scmi_dev); +} + +void scmi_set_handle(struct scmi_device *scmi_dev) +{ + scmi_dev->handle = scmi_handle_get(&scmi_dev->dev); +} + +int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn) +{ + int ret; + + spin_lock(&protocol_lock); + ret = idr_alloc(&scmi_protocols, fn, protocol_id, protocol_id + 1, + GFP_KERNEL); + if (ret != protocol_id) + pr_err("unable to allocate SCMI idr slot, err %d\n", ret); + spin_unlock(&protocol_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(scmi_protocol_register); + +void scmi_protocol_unregister(int protocol_id) +{ + spin_lock(&protocol_lock); + idr_remove(&scmi_protocols, protocol_id); + spin_unlock(&protocol_lock); +} +EXPORT_SYMBOL_GPL(scmi_protocol_unregister); + +static int __scmi_devices_unregister(struct device *dev, void *data) +{ + struct scmi_device *scmi_dev = to_scmi_dev(dev); + + scmi_device_destroy(scmi_dev); + return 0; +} + +static void scmi_devices_unregister(void) +{ + bus_for_each_dev(&scmi_bus_type, NULL, NULL, __scmi_devices_unregister); +} + +static int __init scmi_bus_init(void) +{ + int retval; + + retval = bus_register(&scmi_bus_type); + if (retval) + pr_err("scmi protocol bus register failed (%d)\n", retval); + + return retval; +} +subsys_initcall(scmi_bus_init); + +static void __exit scmi_bus_exit(void) +{ + scmi_devices_unregister(); + bus_unregister(&scmi_bus_type); + ida_destroy(&scmi_bus_id); +} +module_exit(scmi_bus_exit); diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index bc767f4997e0..f1eeacaef57b 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -107,6 +107,7 @@ int scmi_one_xfer_init(const struct scmi_handle *h, u8 msg_id, u8 prot_id, size_t tx_size, size_t rx_size, struct scmi_xfer **p); int scmi_handle_put(const struct scmi_handle *handle); struct scmi_handle *scmi_handle_get(struct device *dev); +void scmi_set_handle(struct scmi_device *scmi_dev); int scmi_version_get(const struct scmi_handle *h, u8 protocol, u32 *version); void scmi_setup_protocol_implemented(const struct scmi_handle *handle, u8 *prot_imp); diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h index 664da3d763f2..7b72c75cb560 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -15,6 +15,7 @@ * You should have received a copy of the GNU General Public License along with * this program. If not, see . */ +#include #include #define SCMI_MAX_STR_SIZE 16 @@ -62,3 +63,64 @@ enum scmi_std_protocol { SCMI_PROTOCOL_CLOCK = 0x14, SCMI_PROTOCOL_SENSOR = 0x15, }; + +struct scmi_device { + u32 id; + u8 protocol_id; + struct device dev; + struct scmi_handle *handle; +}; + +#define to_scmi_dev(d) container_of(d, struct scmi_device, dev) + +struct scmi_device * +scmi_device_create(struct device_node *np, struct device *parent, int protocol); +void scmi_device_destroy(struct scmi_device *scmi_dev); + +struct scmi_device_id { + u8 protocol_id; +}; + +struct scmi_driver { + const char *name; + int (*probe)(struct scmi_device *); + void (*remove)(struct scmi_device *); + const struct scmi_device_id *id_table; + + struct device_driver driver; +}; + +#define to_scmi_driver(d) container_of(d, struct scmi_driver, driver) + +#ifdef CONFIG_ARM_SCMI_PROTOCOL +int scmi_driver_register(struct scmi_driver *driver, + struct module *owner, const char *mod_name); +void scmi_driver_unregister(struct scmi_driver *driver); +#else +static int scmi_driver_register(struct scmi_driver *driver, + struct module *owner, const char *mod_name) +{ + return -EINVAL; +} +static void scmi_driver_unregister(struct scmi_driver *driver) {} +#endif /* CONFIG_ARM_SCMI_PROTOCOL */ + +#define scmi_register(driver) \ + scmi_driver_register(driver, THIS_MODULE, KBUILD_MODNAME) +#define scmi_unregister(driver) \ + scmi_driver_unregister(driver) + +/** + * module_scmi_driver() - Helper macro for registering a scmi driver + * @__scmi_driver: scmi_driver structure + * + * Helper macro for scmi drivers to set up proper module init / exit + * functions. Replaces module_init() and module_exit() and keeps people from + * printing pointless things to the kernel log when their driver is loaded. + */ +#define module_scmi_driver(__scmi_driver) \ + module_driver(__scmi_driver, scmi_register, scmi_unregister) + +typedef int (*scmi_prot_init_fn_t)(struct scmi_handle *); +int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn); +void scmi_protocol_unregister(int protocol_id);