@@ -14911,6 +14911,14 @@ L: platform-driver-x86@vger.kernel.org
S: Maintained
F: drivers/platform/x86/peaq-wmi.c
+PECI SUBSYSTEM
+M: Iwona Winiarska <iwona.winiarska@intel.com>
+L: openbmc@lists.ozlabs.org (moderated for non-subscribers)
+S: Supported
+F: Documentation/devicetree/bindings/peci/
+F: drivers/peci/
+F: include/linux/peci.h
+
PENSANDO ETHERNET DRIVERS
M: Shannon Nelson <snelson@pensando.io>
M: drivers@pensando.io
@@ -236,4 +236,7 @@ source "drivers/interconnect/Kconfig"
source "drivers/counter/Kconfig"
source "drivers/most/Kconfig"
+
+source "drivers/peci/Kconfig"
+
endmenu
@@ -188,3 +188,4 @@ obj-$(CONFIG_GNSS) += gnss/
obj-$(CONFIG_INTERCONNECT) += interconnect/
obj-$(CONFIG_COUNTER) += counter/
obj-$(CONFIG_MOST) += most/
+obj-$(CONFIG_PECI) += peci/
new file mode 100644
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menuconfig PECI
+ tristate "PECI support"
+ help
+ The Platform Environment Control Interface (PECI) is an interface
+ that provides a communication channel to Intel processors and
+ chipset components from external monitoring or control devices.
+
+ If you are building a Baseboard Management Controller (BMC) kernel
+ for Intel platform say Y here and also to the specific driver for
+ your adapter(s) below. If unsure say N.
+
+ This support is also available as a module. If so, the module
+ will be called peci.
new file mode 100644
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+# Core functionality
+peci-y := core.o
+obj-$(CONFIG_PECI) += peci.o
new file mode 100644
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2018-2021 Intel Corporation
+
+#include <linux/bug.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/peci.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+static DEFINE_IDA(peci_controller_ida);
+
+static void peci_controller_dev_release(struct device *dev)
+{
+ struct peci_controller *controller = to_peci_controller(dev);
+
+ mutex_destroy(&controller->bus_lock);
+ ida_free(&peci_controller_ida, controller->id);
+ kfree(controller);
+}
+
+struct device_type peci_controller_type = {
+ .release = peci_controller_dev_release,
+};
+
+static struct peci_controller *peci_controller_alloc(struct device *dev,
+ struct peci_controller_ops *ops)
+{
+ struct peci_controller *controller;
+ int ret;
+
+ if (!ops->xfer)
+ return ERR_PTR(-EINVAL);
+
+ controller = kzalloc(sizeof(*controller), GFP_KERNEL);
+ if (!controller)
+ return ERR_PTR(-ENOMEM);
+
+ ret = ida_alloc_max(&peci_controller_ida, U8_MAX, GFP_KERNEL);
+ if (ret < 0)
+ goto err;
+ controller->id = ret;
+
+ controller->ops = ops;
+
+ controller->dev.parent = dev;
+ controller->dev.bus = &peci_bus_type;
+ controller->dev.type = &peci_controller_type;
+
+ device_initialize(&controller->dev);
+
+ mutex_init(&controller->bus_lock);
+
+ return controller;
+
+err:
+ kfree(controller);
+ return ERR_PTR(ret);
+}
+
+static void unregister_controller(void *_controller)
+{
+ struct peci_controller *controller = _controller;
+
+ device_unregister(&controller->dev);
+
+ fwnode_handle_put(controller->dev.fwnode);
+
+ pm_runtime_disable(&controller->dev);
+}
+
+/**
+ * devm_peci_controller_add() - add PECI controller
+ * @dev: device for devm operations
+ * @ops: pointer to controller specific methods
+ *
+ * In final stage of its probe(), peci_controller driver calls
+ * devm_peci_controller_add() to register itself with the PECI bus.
+ *
+ * Return: Pointer to the newly allocated controller or ERR_PTR() in case of failure.
+ */
+struct peci_controller *devm_peci_controller_add(struct device *dev,
+ struct peci_controller_ops *ops)
+{
+ struct peci_controller *controller;
+ int ret;
+
+ controller = peci_controller_alloc(dev, ops);
+ if (IS_ERR(controller))
+ return controller;
+
+ ret = dev_set_name(&controller->dev, "peci-%d", controller->id);
+ if (ret)
+ goto err_put;
+
+ pm_runtime_no_callbacks(&controller->dev);
+ pm_suspend_ignore_children(&controller->dev, true);
+ pm_runtime_enable(&controller->dev);
+
+ device_set_node(&controller->dev, fwnode_handle_get(dev_fwnode(dev)));
+
+ ret = device_add(&controller->dev);
+ if (ret)
+ goto err_fwnode;
+
+ ret = devm_add_action_or_reset(dev, unregister_controller, controller);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return controller;
+
+err_fwnode:
+ fwnode_handle_put(controller->dev.fwnode);
+
+ pm_runtime_disable(&controller->dev);
+
+err_put:
+ put_device(&controller->dev);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_NS_GPL(devm_peci_controller_add, PECI);
+
+struct bus_type peci_bus_type = {
+ .name = "peci",
+};
+
+static int __init peci_init(void)
+{
+ int ret;
+
+ ret = bus_register(&peci_bus_type);
+ if (ret < 0) {
+ pr_err("peci: failed to register PECI bus type!\n");
+ return ret;
+ }
+
+ return 0;
+}
+module_init(peci_init);
+
+static void __exit peci_exit(void)
+{
+ bus_unregister(&peci_bus_type);
+}
+module_exit(peci_exit);
+
+MODULE_AUTHOR("Jason M Bills <jason.m.bills@linux.intel.com>");
+MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
+MODULE_AUTHOR("Iwona Winiarska <iwona.winiarska@intel.com>");
+MODULE_DESCRIPTION("PECI bus core module");
+MODULE_LICENSE("GPL");
new file mode 100644
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2018-2021 Intel Corporation */
+
+#ifndef __PECI_INTERNAL_H
+#define __PECI_INTERNAL_H
+
+#include <linux/device.h>
+#include <linux/types.h>
+
+struct peci_controller;
+
+extern struct bus_type peci_bus_type;
+
+extern struct device_type peci_controller_type;
+
+#endif /* __PECI_INTERNAL_H */
new file mode 100644
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2018-2021 Intel Corporation */
+
+#ifndef __LINUX_PECI_H
+#define __LINUX_PECI_H
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/types.h>
+
+/*
+ * Currently we don't support any PECI command over 32 bytes.
+ */
+#define PECI_REQUEST_MAX_BUF_SIZE 32
+
+struct peci_controller;
+struct peci_request;
+
+/**
+ * struct peci_controller_ops - PECI controller specific methods
+ * @xfer: PECI transfer function
+ *
+ * PECI controllers may have different hardware interfaces - the drivers
+ * implementing PECI controllers can use this structure to abstract away those
+ * differences by exposing a common interface for PECI core.
+ */
+struct peci_controller_ops {
+ int (*xfer)(struct peci_controller *controller, u8 addr, struct peci_request *req);
+};
+
+/**
+ * struct peci_controller - PECI controller
+ * @dev: device object to register PECI controller to the device model
+ * @ops: pointer to device specific controller operations
+ * @bus_lock: lock used to protect multiple callers
+ * @id: PECI controller ID
+ *
+ * PECI controllers usually connect to their drivers using non-PECI bus,
+ * such as the platform bus.
+ * Each PECI controller can communicate with one or more PECI devices.
+ */
+struct peci_controller {
+ struct device dev;
+ struct peci_controller_ops *ops;
+ struct mutex bus_lock; /* held for the duration of xfer */
+ u8 id;
+};
+
+struct peci_controller *devm_peci_controller_add(struct device *parent,
+ struct peci_controller_ops *ops);
+
+static inline struct peci_controller *to_peci_controller(void *d)
+{
+ return container_of(d, struct peci_controller, dev);
+}
+
+/**
+ * struct peci_device - PECI device
+ * @dev: device object to register PECI device to the device model
+ * @controller: manages the bus segment hosting this PECI device
+ * @addr: address used on the PECI bus connected to the parent controller
+ *
+ * A peci_device identifies a single device (i.e. CPU) connected to a PECI bus.
+ * The behaviour exposed to the rest of the system is defined by the PECI driver
+ * managing the device.
+ */
+struct peci_device {
+ struct device dev;
+ u8 addr;
+};
+
+static inline struct peci_device *to_peci_device(struct device *d)
+{
+ return container_of(d, struct peci_device, dev);
+}
+
+/**
+ * struct peci_request - PECI request
+ * @device: PECI device to which the request is sent
+ * @tx: TX buffer specific data
+ * @tx.buf: TX buffer
+ * @tx.len: transfer data length in bytes
+ * @rx: RX buffer specific data
+ * @rx.buf: RX buffer
+ * @rx.len: received data length in bytes
+ *
+ * A peci_request represents a request issued by PECI originator (TX) and
+ * a response received from PECI responder (RX).
+ */
+struct peci_request {
+ struct peci_device *device;
+ struct {
+ u8 buf[PECI_REQUEST_MAX_BUF_SIZE];
+ u8 len;
+ } rx, tx;
+};
+
+#endif /* __LINUX_PECI_H */