2 files changed, 256 insertions, 0 deletions

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index d16b3c3e1b38..16c7fff50549 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
+#include <linux/sched.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
@@ -25,6 +26,8 @@
 #include <linux/mei_cl_bus.h>
 
 #include "mei_dev.h"
+#include "hw-me.h"
+#include "client.h"
 
 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
 #define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
@@ -81,6 +84,11 @@ static int mei_cl_device_remove(struct device *dev)
         if (!device || !dev->driver)
                 return 0;
 
+        if (device->event_cb) {
+                device->event_cb = NULL;
+                cancel_work_sync(&device->event_work);
+        }
+
         driver = to_mei_cl_driver(dev->driver);
         if (!driver->remove) {
                 dev->driver = NULL;
@@ -196,3 +204,221 @@ void mei_cl_driver_unregister(struct mei_cl_driver *driver)
         pr_debug("mei: driver [%s] unregistered\n", driver->driver.name);
 }
 EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);
+
+int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length)
+{
+        struct mei_device *dev;
+        struct mei_msg_hdr mei_hdr;
+        struct mei_cl_cb *cb;
+        int me_cl_id, err;
+
+        if (WARN_ON(!cl || !cl->dev))
+                return -ENODEV;
+
+        if (cl->state != MEI_FILE_CONNECTED)
+                return -ENODEV;
+
+        cb = mei_io_cb_init(cl, NULL);
+        if (!cb)
+                return -ENOMEM;
+
+        err = mei_io_cb_alloc_req_buf(cb, length);
+        if (err < 0) {
+                mei_io_cb_free(cb);
+                return err;
+        }
+
+        memcpy(cb->request_buffer.data, buf, length);
+        cb->fop_type = MEI_FOP_WRITE;
+
+        dev = cl->dev;
+
+        mutex_lock(&dev->device_lock);
+
+        /* Check if we have an ME client device */
+        me_cl_id = mei_me_cl_by_id(dev, cl->me_client_id);
+        if (me_cl_id == dev->me_clients_num) {
+                err = -ENODEV;
+                goto out_err;
+        }
+
+        if (length > dev->me_clients[me_cl_id].props.max_msg_length) {
+                err = -EINVAL;
+                goto out_err;
+        }
+
+        err = mei_cl_flow_ctrl_creds(cl);
+        if (err < 0)
+                goto out_err;
+
+        /* Host buffer is not ready, we queue the request */
+        if (err == 0 || !dev->hbuf_is_ready) {
+                cb->buf_idx = 0;
+                mei_hdr.msg_complete = 0;
+                cl->writing_state = MEI_WRITING;
+                list_add_tail(&cb->list, &dev->write_list.list);
+
+                mutex_unlock(&dev->device_lock);
+
+                return length;
+        }
+
+        dev->hbuf_is_ready = false;
+
+        /* Check for a maximum length */
+        if (length > mei_hbuf_max_len(dev)) {
+                mei_hdr.length = mei_hbuf_max_len(dev);
+                mei_hdr.msg_complete = 0;
+        } else {
+                mei_hdr.length = length;
+                mei_hdr.msg_complete = 1;
+        }
+
+        mei_hdr.host_addr = cl->host_client_id;
+        mei_hdr.me_addr = cl->me_client_id;
+        mei_hdr.reserved = 0;
+
+        if (mei_write_message(dev, &mei_hdr, buf)) {
+                err = -EIO;
+                goto out_err;
+        }
+
+        cl->writing_state = MEI_WRITING;
+        cb->buf_idx = mei_hdr.length;
+
+        if (!mei_hdr.msg_complete) {
+                list_add_tail(&cb->list, &dev->write_list.list);
+        } else {
+                if (mei_cl_flow_ctrl_reduce(cl)) {
+                        err = -EIO;
+                        goto out_err;
+                }
+
+                list_add_tail(&cb->list, &dev->write_waiting_list.list);
+        }
+
+        mutex_unlock(&dev->device_lock);
+
+        return mei_hdr.length;
+
+out_err:
+        mutex_unlock(&dev->device_lock);
+        mei_io_cb_free(cb);
+
+        return err;
+}
+
+int __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
+{
+        struct mei_device *dev;
+        struct mei_cl_cb *cb;
+        size_t r_length;
+        int err;
+
+        if (WARN_ON(!cl || !cl->dev))
+                return -ENODEV;
+
+        dev = cl->dev;
+
+        mutex_lock(&dev->device_lock);
+
+        if (!cl->read_cb) {
+                err = mei_cl_read_start(cl);
+                if (err < 0) {
+                        mutex_unlock(&dev->device_lock);
+                        return err;
+                }
+        }
+
+        if (cl->reading_state != MEI_READ_COMPLETE &&
+            !waitqueue_active(&cl->rx_wait)) {
+                mutex_unlock(&dev->device_lock);
+
+                if (wait_event_interruptible(cl->rx_wait,
+                                (MEI_READ_COMPLETE == cl->reading_state))) {
+                        if (signal_pending(current))
+                                return -EINTR;
+                        return -ERESTARTSYS;
+                }
+
+                mutex_lock(&dev->device_lock);
+        }
+
+        cb = cl->read_cb;
+
+        if (cl->reading_state != MEI_READ_COMPLETE) {
+                r_length = 0;
+                goto out;
+        }
+
+        r_length = min_t(size_t, length, cb->buf_idx);
+
+        memcpy(buf, cb->response_buffer.data, r_length);
+
+        mei_io_cb_free(cb);
+        cl->reading_state = MEI_IDLE;
+        cl->read_cb = NULL;
+
+out:
+        mutex_unlock(&dev->device_lock);
+
+        return r_length;
+}
+
+int mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length)
+{
+        struct mei_cl *cl = NULL;
+
+        /* TODO: hook between mei_bus_client and mei_cl */
+
+        if (device->ops && device->ops->send)
+                return device->ops->send(device, buf, length);
+
+        return __mei_cl_send(cl, buf, length);
+}
+EXPORT_SYMBOL_GPL(mei_cl_send);
+
+int mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length)
+{
+        struct mei_cl *cl = NULL;
+
+        /* TODO: hook between mei_bus_client and mei_cl */
+
+        if (device->ops && device->ops->recv)
+                return device->ops->recv(device, buf, length);
+
+        return __mei_cl_recv(cl, buf, length);
+}
+EXPORT_SYMBOL_GPL(mei_cl_recv);
+
+static void mei_bus_event_work(struct work_struct *work)
+{
+        struct mei_cl_device *device;
+
+        device = container_of(work, struct mei_cl_device, event_work);
+
+        if (device->event_cb)
+                device->event_cb(device, device->events, device->event_context);
+
+        device->events = 0;
+
+        /* Prepare for the next read */
+        mei_cl_read_start(device->cl);
+}
+
+int mei_cl_register_event_cb(struct mei_cl_device *device,
+                          mei_cl_event_cb_t event_cb, void *context)
+{
+        if (device->event_cb)
+                return -EALREADY;
+
+        device->events = 0;
+        device->event_cb = event_cb;
+        device->event_context = context;
+        INIT_WORK(&device->event_work, mei_bus_event_work);
+
+        mei_cl_read_start(device->cl);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 7abb705ddf3f..cde5687039f3 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -268,6 +268,25 @@ struct mei_cl_device *mei_cl_add_device(struct mei_device *dev,
                                   uuid_le uuid, char *name);
 void mei_cl_remove_device(struct mei_cl_device *device);
 
+int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length);
+int __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length);
+
+/**
+ * struct mei_cl_transport_ops - MEI CL device transport ops
+ * This structure allows ME host clients to implement technology
+ * specific transport layers.
+ *
+ * @send: Tx hook for the device. This allows ME host clients to trap
+ *      the device driver buffers before actually physically
+ *      pushing it to the ME.
+ * @recv: Rx hook for the device. This allows ME host clients to trap the
+ *      ME buffers before forwarding them to the device driver.
+ */
+struct mei_cl_transport_ops {
+        int (*send)(struct mei_cl_device *device, u8 *buf, size_t length);
+        int (*recv)(struct mei_cl_device *device, u8 *buf, size_t length);
+};
+
 /**
  * struct mei_cl_device - MEI device handle
  * An mei_cl_device pointer is returned from mei_add_device()
@@ -278,6 +297,10 @@ void mei_cl_remove_device(struct mei_cl_device *device);
  * @dev: linux driver model device pointer
  * @uuid: me client uuid
  * @cl: mei client
+ * @ops: ME transport ops
+ * @event_cb: Drivers register this callback to get asynchronous ME
+ *      events (e.g. Rx buffer pending) notifications.
+ * @events: Events bitmask sent to the driver.
  * @priv_data: client private data
  */
 struct mei_cl_device {
@@ -285,6 +308,13 @@ struct mei_cl_device {
 
         struct mei_cl *cl;
 
+        const struct mei_cl_transport_ops *ops;
+
+        struct work_struct event_work;
+        mei_cl_event_cb_t event_cb;
+        void *event_context;
+        unsigned long events;
+
         void *priv_data;
 };