HID: intel_ish-hid: ISH Transport layer

The ISH transport layer (ishtp) is a bi-directional protocol implemented
on the top of PCI based inter processor communication layer. This layer
offers:
- Connection management
- Flow control with the firmware
- Multiple client sessions
- Client message transfer
- Client message reception
- DMA for RX and TX for fast data transfer

Refer to Documentation/hid/intel-ish-hid.txt for
overview of the functionality implemented in this layer.

Original-author: Daniel Drubin <daniel.drubin@intel.com>
Reviewed-and-tested-by: Ooi, Joyce <joyce.ooi@intel.com>
Tested-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Rann Bar-On <rb6@duke.edu>
Tested-by: Atri Bhattacharya <badshah400@aim.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 115 insertions, 0 deletions

diff --git a/drivers/hid/intel-ish-hid/ishtp/init.c b/drivers/hid/intel-ish-hid/ishtp/init.c
new file mode 100644
index 000000000000..ac364418e17c
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ishtp/init.c
@@ -0,0 +1,115 @@
+/*
+ * Initialization protocol for ISHTP driver
+ *
+ * Copyright (c) 2003-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/miscdevice.h>
+#include "ishtp-dev.h"
+#include "hbm.h"
+#include "client.h"
+
+/**
+ * ishtp_dev_state_str() -Convert to string format
+ * @state: state to convert
+ *
+ * Convert state to string for prints
+ *
+ * Return: character pointer to converted string
+ */
+const char *ishtp_dev_state_str(int state)
+{
+	switch (state) {
+	case ISHTP_DEV_INITIALIZING:
+		return	"INITIALIZING";
+	case ISHTP_DEV_INIT_CLIENTS:
+		return	"INIT_CLIENTS";
+	case ISHTP_DEV_ENABLED:
+		return	"ENABLED";
+	case ISHTP_DEV_RESETTING:
+		return	"RESETTING";
+	case ISHTP_DEV_DISABLED:
+		return	"DISABLED";
+	case ISHTP_DEV_POWER_DOWN:
+		return	"POWER_DOWN";
+	case ISHTP_DEV_POWER_UP:
+		return	"POWER_UP";
+	default:
+		return "unknown";
+	}
+}
+
+/**
+ * ishtp_device_init() - ishtp device init
+ * @dev: ISHTP device instance
+ *
+ * After ISHTP device is alloacted, this function is used to initialize
+ * each field which includes spin lock, work struct and lists
+ */
+void ishtp_device_init(struct ishtp_device *dev)
+{
+	dev->dev_state = ISHTP_DEV_INITIALIZING;
+	INIT_LIST_HEAD(&dev->cl_list);
+	INIT_LIST_HEAD(&dev->device_list);
+	dev->rd_msg_fifo_head = 0;
+	dev->rd_msg_fifo_tail = 0;
+	spin_lock_init(&dev->rd_msg_spinlock);
+
+	init_waitqueue_head(&dev->wait_hbm_recvd_msg);
+	spin_lock_init(&dev->read_list_spinlock);
+	spin_lock_init(&dev->device_lock);
+	spin_lock_init(&dev->device_list_lock);
+	spin_lock_init(&dev->cl_list_lock);
+	spin_lock_init(&dev->fw_clients_lock);
+	INIT_WORK(&dev->bh_hbm_work, bh_hbm_work_fn);
+
+	bitmap_zero(dev->host_clients_map, ISHTP_CLIENTS_MAX);
+	dev->open_handle_count = 0;
+
+	/*
+	 * Reserving client ID 0 for ISHTP Bus Message communications
+	 */
+	bitmap_set(dev->host_clients_map, 0, 1);
+
+	INIT_LIST_HEAD(&dev->read_list.list);
+
+}
+EXPORT_SYMBOL(ishtp_device_init);
+
+/**
+ * ishtp_start() - Start ISH processing
+ * @dev: ISHTP device instance
+ *
+ * Start ISHTP processing by sending query subscriber message
+ *
+ * Return: 0 on success else -ENODEV
+ */
+int ishtp_start(struct ishtp_device *dev)
+{
+	if (ishtp_hbm_start_wait(dev)) {
+		dev_err(dev->devc, "HBM haven't started");
+		goto err;
+	}
+
+	/* suspend & resume notification - send QUERY_SUBSCRIBERS msg */
+	ishtp_query_subscribers(dev);
+
+	return 0;
+err:
+	dev_err(dev->devc, "link layer initialization failed.\n");
+	dev->dev_state = ISHTP_DEV_DISABLED;
+	return -ENODEV;
+}
+EXPORT_SYMBOL(ishtp_start);