--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright © 2020 - 2021 Intel Corporation
+ */
+
+/**
+ * DOC: MEI_PXP Client Driver
+ *
+ * The mei_pxp driver acts as a translation layer between PXP
+ * protocol implementer (I915) and ME FW by translating PXP
+ * negotiation messages to ME FW command payloads and vice versa.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/uuid.h>
+#include <linux/mei_cl_bus.h>
+#include <linux/component.h>
+#include <drm/drm_connector.h>
+#include <drm/i915_component.h>
+#include <drm/i915_pxp_tee_interface.h>
+
+#include "mei_pxp.h"
+
+/**
+ * mei_pxp_send_message() - Sends a PXP message to ME FW.
+ * @dev: device corresponding to the mei_cl_device
+ * @message: a message buffer to send
+ * @size: size of the message
+ * Return: 0 on Success, <0 on Failure
+ */
+static int
+mei_pxp_send_message(struct device *dev, const void *message, size_t size)
+{
+ struct mei_cl_device *cldev;
+ ssize_t byte;
+
+ if (!dev || !message)
+ return -EINVAL;
+
+ cldev = to_mei_cl_device(dev);
+
+ /* temporary drop const qualifier till the API is fixed */
+ byte = mei_cldev_send(cldev, (u8 *)message, size);
+ if (byte < 0) {
+ dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
+ return byte;
+ }
+
+ return 0;
+}
+
+/**
+ * mei_pxp_receive_message() - Receives a PXP message from ME FW.
+ * @dev: device corresponding to the mei_cl_device
+ * @buffer: a message buffer to contain the received message
+ * @size: size of the buffer
+ * Return: bytes sent on Success, <0 on Failure
+ */
+static int
+mei_pxp_receive_message(struct device *dev, void *buffer, size_t size)
+{
+ struct mei_cl_device *cldev;
+ ssize_t byte;
+
+ if (!dev || !buffer)
+ return -EINVAL;
+
+ cldev = to_mei_cl_device(dev);
+
+ byte = mei_cldev_recv(cldev, buffer, size);
+ if (byte < 0) {
+ dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
+ return byte;
+ }
+
+ return byte;
+}
+
+static const struct i915_pxp_component_ops mei_pxp_ops = {
+ .owner = THIS_MODULE,
+ .send = mei_pxp_send_message,
+ .recv = mei_pxp_receive_message,
+};
+
+static int mei_component_master_bind(struct device *dev)
+{
+ struct mei_cl_device *cldev = to_mei_cl_device(dev);
+ struct i915_pxp_component *comp_master = mei_cldev_get_drvdata(cldev);
+ int ret;
+
+ comp_master->ops = &mei_pxp_ops;
+ comp_master->tee_dev = dev;
+ ret = component_bind_all(dev, comp_master);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static void mei_component_master_unbind(struct device *dev)
+{
+ struct mei_cl_device *cldev = to_mei_cl_device(dev);
+ struct i915_pxp_component *comp_master = mei_cldev_get_drvdata(cldev);
+
+ component_unbind_all(dev, comp_master);
+}
+
+static const struct component_master_ops mei_component_master_ops = {
+ .bind = mei_component_master_bind,
+ .unbind = mei_component_master_unbind,
+};
+
+/**
+ * mei_pxp_component_match - compare function for matching mei pxp.
+ *
+ * The function checks if the driver is i915, the subcomponent is PXP
+ * and the grand parent of pxp and the parent of i915 are the same
+ * PCH device.
+ *
+ * @dev: master device
+ * @subcomponent: subcomponent to match (I915_COMPONENT_PXP)
+ * @data: compare data (mei pxp device)
+ *
+ * Return:
+ * * 1 - if components match
+ * * 0 - otherwise
+ */
+static int mei_pxp_component_match(struct device *dev, int subcomponent,
+ void *data)
+{
+ struct device *base = data;
+
+ if (strcmp(dev->driver->name, "i915") ||
+ subcomponent != I915_COMPONENT_PXP)
+ return 0;
+
+ base = base->parent;
+ if (!base)
+ return 0;
+
+ base = base->parent;
+ dev = dev->parent;
+
+ return (base && dev && dev == base);
+}
+
+static int mei_pxp_probe(struct mei_cl_device *cldev,
+ const struct mei_cl_device_id *id)
+{
+ struct i915_pxp_component *comp_master;
+ struct component_match *master_match;
+ int ret;
+
+ ret = mei_cldev_enable(cldev);
+ if (ret < 0) {
+ dev_err(&cldev->dev, "mei_cldev_enable Failed. %d\n", ret);
+ goto enable_err_exit;
+ }
+
+ comp_master = kzalloc(sizeof(*comp_master), GFP_KERNEL);
+ if (!comp_master) {
+ ret = -ENOMEM;
+ goto err_exit;
+ }
+
+ master_match = NULL;
+ component_match_add_typed(&cldev->dev, &master_match,
+ mei_pxp_component_match, &cldev->dev);
+ if (IS_ERR_OR_NULL(master_match)) {
+ ret = -ENOMEM;
+ goto err_exit;
+ }
+
+ mei_cldev_set_drvdata(cldev, comp_master);
+ ret = component_master_add_with_match(&cldev->dev,
+ &mei_component_master_ops,
+ master_match);
+ if (ret < 0) {
+ dev_err(&cldev->dev, "Master comp add failed %d\n", ret);
+ goto err_exit;
+ }
+
+ return 0;
+
+err_exit:
+ mei_cldev_set_drvdata(cldev, NULL);
+ kfree(comp_master);
+ mei_cldev_disable(cldev);
+enable_err_exit:
+ return ret;
+}
+
+static void mei_pxp_remove(struct mei_cl_device *cldev)
+{
+ struct i915_pxp_component *comp_master = mei_cldev_get_drvdata(cldev);
+ int ret;
+
+ component_master_del(&cldev->dev, &mei_component_master_ops);
+ kfree(comp_master);
+ mei_cldev_set_drvdata(cldev, NULL);
+
+ ret = mei_cldev_disable(cldev);
+ if (ret)
+ dev_warn(&cldev->dev, "mei_cldev_disable() failed\n");
+}
+
+/* fbf6fcf1-96cf-4e2e-a6a6-1bab8cbe36b1 : PAVP GUID*/
+#define MEI_GUID_PXP GUID_INIT(0xfbf6fcf1, 0x96cf, 0x4e2e, 0xA6, \
+ 0xa6, 0x1b, 0xab, 0x8c, 0xbe, 0x36, 0xb1)
+
+static struct mei_cl_device_id mei_pxp_tbl[] = {
+ { .uuid = MEI_GUID_PXP, .version = MEI_CL_VERSION_ANY },
+ { }
+};
+MODULE_DEVICE_TABLE(mei, mei_pxp_tbl);
+
+static struct mei_cl_driver mei_pxp_driver = {
+ .id_table = mei_pxp_tbl,
+ .name = KBUILD_MODNAME,
+ .probe = mei_pxp_probe,
+ .remove = mei_pxp_remove,
+};
+
+module_mei_cl_driver(mei_pxp_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MEI PXP");
projects / platform / kernel / linux-starfive.git / commitdiff