On 3/18/2020 7:36 AM, Greg KH wrote:
On Thu, Feb 20, 2020 at 03:28:41PM +0530, Manivannan Sadhasivam wrote:
This commit adds support for registering MHI client drivers with the
MHI stack. MHI client drivers binds to one or more MHI devices inorder
to sends and receive the upper-layer protocol packets like IP packets,
modem control messages, and diagnostics messages over MHI bus.
This is based on the patch submitted by Sujeev Dias:
https://lkml.org/lkml/2018/7/9/987
Signed-off-by: Sujeev Dias <sdias@xxxxxxxxxxxxxx>
Signed-off-by: Siddartha Mohanadoss <smohanad@xxxxxxxxxxxxxx>
[mani: splitted and cleaned up for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Reviewed-by: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>
Tested-by: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>
---
drivers/bus/mhi/core/init.c | 149 ++++++++++++++++++++++++++++++++++++
include/linux/mhi.h | 39 ++++++++++
2 files changed, 188 insertions(+)
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 6f24c21284ec..12e386862b3f 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -374,8 +374,157 @@ struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl)
return mhi_dev;
}
+static int mhi_driver_probe(struct device *dev)
+{
+ struct mhi_device *mhi_dev = to_mhi_device(dev);
+ struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+ struct device_driver *drv = dev->driver;
+ struct mhi_driver *mhi_drv = to_mhi_driver(drv);
+ struct mhi_event *mhi_event;
+ struct mhi_chan *ul_chan = mhi_dev->ul_chan;
+ struct mhi_chan *dl_chan = mhi_dev->dl_chan;
+
+ if (ul_chan) {
+ /*
+ * If channel supports LPM notifications then status_cb should
+ * be provided
+ */
+ if (ul_chan->lpm_notify && !mhi_drv->status_cb)
+ return -EINVAL;
+
+ /* For non-offload channels then xfer_cb should be provided */
+ if (!ul_chan->offload_ch && !mhi_drv->ul_xfer_cb)
+ return -EINVAL;
+
+ ul_chan->xfer_cb = mhi_drv->ul_xfer_cb;
+ }
+
+ if (dl_chan) {
+ /*
+ * If channel supports LPM notifications then status_cb should
+ * be provided
+ */
+ if (dl_chan->lpm_notify && !mhi_drv->status_cb)
+ return -EINVAL;
+
+ /* For non-offload channels then xfer_cb should be provided */
+ if (!dl_chan->offload_ch && !mhi_drv->dl_xfer_cb)
+ return -EINVAL;
+
+ mhi_event = &mhi_cntrl->mhi_event[dl_chan->er_index];
+
+ /*
+ * If the channel event ring is managed by client, then
+ * status_cb must be provided so that the framework can
+ * notify pending data
+ */
+ if (mhi_event->cl_manage && !mhi_drv->status_cb)
+ return -EINVAL;
+
+ dl_chan->xfer_cb = mhi_drv->dl_xfer_cb;
+ }
+
+ /* Call the user provided probe function */
+ return mhi_drv->probe(mhi_dev, mhi_dev->id);
+}
+
+static int mhi_driver_remove(struct device *dev)
+{
+ struct mhi_device *mhi_dev = to_mhi_device(dev);
+ struct mhi_driver *mhi_drv = to_mhi_driver(dev->driver);
+ struct mhi_chan *mhi_chan;
+ enum mhi_ch_state ch_state[] = {
+ MHI_CH_STATE_DISABLED,
+ MHI_CH_STATE_DISABLED
+ };
+ int dir;
+
+ /* Skip if it is a controller device */
+ if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
+ return 0;
+
+ /* Reset both channels */
+ for (dir = 0; dir < 2; dir++) {
+ mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
+
+ if (!mhi_chan)
+ continue;
+
+ /* Wake all threads waiting for completion */
+ write_lock_irq(&mhi_chan->lock);
+ mhi_chan->ccs = MHI_EV_CC_INVALID;
+ complete_all(&mhi_chan->completion);
+ write_unlock_irq(&mhi_chan->lock);
+
+ /* Set the channel state to disabled */
+ mutex_lock(&mhi_chan->mutex);
+ write_lock_irq(&mhi_chan->lock);
+ ch_state[dir] = mhi_chan->ch_state;
+ mhi_chan->ch_state = MHI_CH_STATE_SUSPENDED;
+ write_unlock_irq(&mhi_chan->lock);
+
+ mutex_unlock(&mhi_chan->mutex);
+ }
+
+ mhi_drv->remove(mhi_dev);
+
+ /* De-init channel if it was enabled */
+ for (dir = 0; dir < 2; dir++) {
+ mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
+
+ if (!mhi_chan)
+ continue;
+
+ mutex_lock(&mhi_chan->mutex);
+
+ mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
+
+ mutex_unlock(&mhi_chan->mutex);
+ }
+
+ return 0;
+}
+
+int mhi_driver_register(struct mhi_driver *mhi_drv)
+{
+ struct device_driver *driver = &mhi_drv->driver;
+
+ if (!mhi_drv->probe || !mhi_drv->remove)
+ return -EINVAL;
+
+ driver->bus = &mhi_bus_type;
+ driver->probe = mhi_driver_probe;
+ driver->remove = mhi_driver_remove;
+
+ return driver_register(driver);
+}
+EXPORT_SYMBOL_GPL(mhi_driver_register);
You don't care about module owners of the driver? Odd :(
(hint, you probably should...)
greg k-h
For my own education, can you please clarify your comment? I'm not sure
that I understand the context of what you are saying (ie why is this
export a possible problem?).
--
Jeffrey Hugo
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
