[PATCH 054/379][SRU][OEM-5.6] bus: mhi: core: Add support for creating and destroying MHI devices

[You-Sheng Yang]

From: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>

BugLink: https://bugs.launchpad.net/bugs/1879633

This commit adds support for creating and destroying MHI devices. The
MHI devices binds to the MHI channels and are used to transfer data
between MHI host and client device.

This is based on the patch submitted by Sujeev Dias:
https://lkml.org/lkml/2018/7/9/989

Signed-off-by: Sujeev Dias <sdias at codeaurora.org>
Signed-off-by: Siddartha Mohanadoss <smohanad at codeaurora.org>
[mani: splitted from pm patch and cleaned up for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
Reviewed-by: Jeffrey Hugo <jhugo at codeaurora.org>
Tested-by: Jeffrey Hugo <jhugo at codeaurora.org>
Link: https://lore.kernel.org/r/20200220095854.4804-5-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit da1c4f85692476ab038e3279209f07b8f4b7641e)
Signed-off-by: You-Sheng Yang <vicamo.yang at canonical.com>
---
 drivers/bus/mhi/core/Makefile |   2 +-
 drivers/bus/mhi/core/main.c   | 123 ++++++++++++++++++++++++++++++++++
 include/linux/mhi.h           |   2 +
 3 files changed, 126 insertions(+), 1 deletion(-)
 create mode 100644 drivers/bus/mhi/core/main.c

diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
index 2db32697c67f..77f7730da4bf 100644
--- a/drivers/bus/mhi/core/Makefile
+++ b/drivers/bus/mhi/core/Makefile
@@ -1,3 +1,3 @@
 obj-$(CONFIG_MHI_BUS) := mhi.o
 
-mhi-y := init.o
+mhi-y := init.o main.o
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
new file mode 100644
index 000000000000..7c35744ec0c0
--- /dev/null
+++ b/drivers/bus/mhi/core/main.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mhi.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+int mhi_destroy_device(struct device *dev, void *data)
+{
+	struct mhi_device *mhi_dev;
+	struct mhi_controller *mhi_cntrl;
+
+	if (dev->bus != &mhi_bus_type)
+		return 0;
+
+	mhi_dev = to_mhi_device(dev);
+	mhi_cntrl = mhi_dev->mhi_cntrl;
+
+	/* Only destroy virtual devices thats attached to bus */
+	if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
+		return 0;
+
+	dev_dbg(&mhi_cntrl->mhi_dev->dev, "destroy device for chan:%s\n",
+		 mhi_dev->chan_name);
+
+	/* Notify the client and remove the device from MHI bus */
+	device_del(dev);
+	put_device(dev);
+
+	return 0;
+}
+
+static void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
+{
+	struct mhi_driver *mhi_drv;
+
+	if (!mhi_dev->dev.driver)
+		return;
+
+	mhi_drv = to_mhi_driver(mhi_dev->dev.driver);
+
+	if (mhi_drv->status_cb)
+		mhi_drv->status_cb(mhi_dev, cb_reason);
+}
+
+/* Bind MHI channels to MHI devices */
+void mhi_create_devices(struct mhi_controller *mhi_cntrl)
+{
+	struct mhi_chan *mhi_chan;
+	struct mhi_device *mhi_dev;
+	struct device *dev = &mhi_cntrl->mhi_dev->dev;
+	int i, ret;
+
+	mhi_chan = mhi_cntrl->mhi_chan;
+	for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
+		if (!mhi_chan->configured || mhi_chan->mhi_dev ||
+		    !(mhi_chan->ee_mask & BIT(mhi_cntrl->ee)))
+			continue;
+		mhi_dev = mhi_alloc_device(mhi_cntrl);
+		if (!mhi_dev)
+			return;
+
+		mhi_dev->dev_type = MHI_DEVICE_XFER;
+		switch (mhi_chan->dir) {
+		case DMA_TO_DEVICE:
+			mhi_dev->ul_chan = mhi_chan;
+			mhi_dev->ul_chan_id = mhi_chan->chan;
+			break;
+		case DMA_FROM_DEVICE:
+			/* We use dl_chan as offload channels */
+			mhi_dev->dl_chan = mhi_chan;
+			mhi_dev->dl_chan_id = mhi_chan->chan;
+			break;
+		default:
+			dev_err(dev, "Direction not supported\n");
+			put_device(&mhi_dev->dev);
+			return;
+		}
+
+		get_device(&mhi_dev->dev);
+		mhi_chan->mhi_dev = mhi_dev;
+
+		/* Check next channel if it matches */
+		if ((i + 1) < mhi_cntrl->max_chan && mhi_chan[1].configured) {
+			if (!strcmp(mhi_chan[1].name, mhi_chan->name)) {
+				i++;
+				mhi_chan++;
+				if (mhi_chan->dir == DMA_TO_DEVICE) {
+					mhi_dev->ul_chan = mhi_chan;
+					mhi_dev->ul_chan_id = mhi_chan->chan;
+				} else {
+					mhi_dev->dl_chan = mhi_chan;
+					mhi_dev->dl_chan_id = mhi_chan->chan;
+				}
+				get_device(&mhi_dev->dev);
+				mhi_chan->mhi_dev = mhi_dev;
+			}
+		}
+
+		/* Channel name is same for both UL and DL */
+		mhi_dev->chan_name = mhi_chan->name;
+		dev_set_name(&mhi_dev->dev, "%04x_%s", mhi_chan->chan,
+			     mhi_dev->chan_name);
+
+		/* Init wakeup source if available */
+		if (mhi_dev->dl_chan && mhi_dev->dl_chan->wake_capable)
+			device_init_wakeup(&mhi_dev->dev, true);
+
+		ret = device_add(&mhi_dev->dev);
+		if (ret)
+			put_device(&mhi_dev->dev);
+	}
+}
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 7e6b7743c705..1ce2bdd5f2f4 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -163,6 +163,7 @@ enum mhi_db_brst_mode {
  * @doorbell_mode_switch: Channel switches to doorbell mode on M0 transition
  * @auto_queue: Framework will automatically queue buffers for DL traffic
  * @auto_start: Automatically start (open) this channel
+ * @wake-capable: Channel capable of waking up the system
  */
 struct mhi_channel_config {
 	char *name;
@@ -180,6 +181,7 @@ struct mhi_channel_config {
 	bool doorbell_mode_switch;
 	bool auto_queue;
 	bool auto_start;
+	bool wake_capable;
 };
 
 /**
-- 
2.29.2