[v5 5/8] Bluetooth: btrsi: add new rsi bluetooth driver

[Amitkumar Karwar <amitkarwar@gmail.com>]

From: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>

Redpine bluetooth driver is a thin driver which depends on
'rsi_91x' driver for transmitting and receiving packets
to/from device. It creates hci interface when attach() is
called from 'rsi_91x' module.

Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
---
v5: Addressed review comments from Marcel.
    Removed reduntant switch case code from rsi_hci_recv_pkt()
    Changed bt_cb(skb)->pkt_type to hci_skb_pkt_type(skb)
    Removed reduntant '\n' from BT_ERR and redundant BT_INFO messages
    Changed u8 *pkt to const u8 *pkt in rsi_hci_recv_pkt()
v4: Removed rsi_hci.h file. Made the functions static(Marcel)
v3: Made BT_RSI module by default off(Marcel)
    Removed redundant exported function rsi_get_hci_ops()(Marcel)
v2: Addressed review comments from Marcel
    Removed unnecessary 'depends on BT && BT_RFOMM' line in Kconfig
    Removed redundant BT_INFO messages
    h_adapter initialization and declaration in a single line.
    Removed unnecessary error checks for HCI_RUNNING and fsm_state
    Allocated new skb with skb_realloc_headroom() API if headroom is not sufficient
    Used get_unaligned_le16 helpers
    Moved a structure and union from header file to btrsi.c file
---
 drivers/bluetooth/Kconfig  |  11 +++
 drivers/bluetooth/Makefile |   2 +
 drivers/bluetooth/btrsi.c  | 188 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/rsi_header.h |   4 +-
 4 files changed, 204 insertions(+), 1 deletion(-)
 create mode 100644 drivers/bluetooth/btrsi.c

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 60e1c7d..33d7514 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -378,4 +378,15 @@ config BT_QCOMSMD
 	  Say Y here to compile support for HCI over Qualcomm SMD into the
 	  kernel or say M to compile as a module.
 
+config BT_RSI
+	tristate "Redpine HCI support"
+	default n
+	help
+	  Redpine BT driver.
+	  This driver handles BT traffic from upper layers and pass
+	  to the RSI_91x coex module for further scheduling to device
+
+	  Say Y here to compile support for HCI over Redpine into the
+	  kernel or say M to compile as a module.
+
 endmenu
diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
index 4e4e44d..712af83a 100644
--- a/drivers/bluetooth/Makefile
+++ b/drivers/bluetooth/Makefile
@@ -28,6 +28,8 @@ obj-$(CONFIG_BT_QCA)		+= btqca.o
 
 obj-$(CONFIG_BT_HCIUART_NOKIA)	+= hci_nokia.o
 
+obj-$(CONFIG_BT_RSI)		+= btrsi.o
+
 btmrvl-y			:= btmrvl_main.o
 btmrvl-$(CONFIG_DEBUG_FS)	+= btmrvl_debugfs.o
 
diff --git a/drivers/bluetooth/btrsi.c b/drivers/bluetooth/btrsi.c
new file mode 100644
index 0000000..c9e92cc
--- /dev/null
+++ b/drivers/bluetooth/btrsi.c
@@ -0,0 +1,188 @@
+/**
+ * Copyright (c) 2017 Redpine Signals Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <linux/unaligned/le_byteshift.h>
+#include <linux/rsi_header.h>
+#include <net/genetlink.h>
+
+#define RSI_HEADROOM_FOR_BT_HAL	16
+#define RSI_FRAME_DESC_SIZE	16
+
+static struct rsi_hci_adapter {
+	void *priv;
+	struct rsi_proto_ops *proto_ops;
+	struct hci_dev *hdev;
+};
+
+static int rsi_hci_open(struct hci_dev *hdev)
+{
+	return 0;
+}
+
+static int rsi_hci_close(struct hci_dev *hdev)
+{
+	return 0;
+}
+
+static int rsi_hci_flush(struct hci_dev *hdev)
+{
+	return 0;
+}
+
+static int rsi_hci_send_pkt(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct rsi_hci_adapter *h_adapter = hci_get_drvdata(hdev);
+	struct sk_buff *new_skb = NULL;
+
+	switch (hci_skb_pkt_type(skb)) {
+	case HCI_COMMAND_PKT:
+		hdev->stat.cmd_tx++;
+		break;
+	case HCI_ACLDATA_PKT:
+		hdev->stat.acl_tx++;
+		break;
+	case HCI_SCODATA_PKT:
+		hdev->stat.sco_tx++;
+		break;
+	}
+
+	if (skb_headroom(skb) < RSI_HEADROOM_FOR_BT_HAL) {
+		/* Insufficient skb headroom - allocate a new skb */
+		new_skb = skb_realloc_headroom(skb, RSI_HEADROOM_FOR_BT_HAL);
+		if (unlikely(!new_skb))
+			return -ENOMEM;
+		bt_cb(new_skb)->pkt_type = hci_skb_pkt_type(skb);
+		kfree_skb(skb);
+		skb = new_skb;
+	}
+
+	return h_adapter->proto_ops->coex_send_pkt(h_adapter->priv, skb,
+						   RSI_BT_Q);
+}
+
+static int rsi_hci_recv_pkt(void *priv, const u8 *pkt)
+{
+	struct rsi_hci_adapter *h_adapter = priv;
+	struct hci_dev *hdev = h_adapter->hdev;
+	struct sk_buff *skb;
+	int pkt_len = get_unaligned_le16(pkt) & 0x0fff;
+
+	skb = dev_alloc_skb(pkt_len);
+	if (!skb)
+		return -ENOMEM;
+
+	memcpy(skb->data, pkt + RSI_FRAME_DESC_SIZE, pkt_len);
+	skb_put(skb, pkt_len);
+	h_adapter->hdev->stat.byte_rx += skb->len;
+
+	hci_skb_pkt_type(skb) = pkt[14];
+
+	return hci_recv_frame(hdev, skb);
+}
+
+static int rsi_hci_attach(void *priv, struct rsi_proto_ops *ops)
+{
+	struct rsi_hci_adapter *h_adapter = NULL;
+	struct hci_dev *hdev;
+	int err = 0;
+
+	h_adapter = kzalloc(sizeof(*h_adapter), GFP_KERNEL);
+	if (!h_adapter)
+		return -ENOMEM;
+
+	h_adapter->priv = priv;
+	ops->set_bt_context(priv, h_adapter);
+	h_adapter->proto_ops = ops;
+
+	hdev = hci_alloc_dev();
+	if (!hdev) {
+		BT_ERR("Failed to alloc HCI device");
+		goto err;
+	}
+
+	h_adapter->hdev = hdev;
+
+	if (ops->get_host_intf(priv) == RSI_HOST_INTF_SDIO)
+		hdev->bus = HCI_SDIO;
+	else
+		hdev->bus = HCI_USB;
+
+	hci_set_drvdata(hdev, h_adapter);
+	hdev->dev_type = HCI_PRIMARY;
+	hdev->open = rsi_hci_open;
+	hdev->close = rsi_hci_close;
+	hdev->flush = rsi_hci_flush;
+	hdev->send = rsi_hci_send_pkt;
+
+	err = hci_register_dev(hdev);
+	if (err < 0) {
+		BT_ERR("HCI registration failed with errcode %d", err);
+		hci_free_dev(hdev);
+		goto err;
+	}
+
+	return 0;
+err:
+	h_adapter->hdev = NULL;
+	kfree(h_adapter);
+	return -EINVAL;
+}
+
+static void rsi_hci_detach(void *priv)
+{
+	struct rsi_hci_adapter *h_adapter = priv;
+	struct hci_dev *hdev;
+
+	if (!h_adapter)
+		return;
+
+	hdev = h_adapter->hdev;
+	if (hdev) {
+		hci_unregister_dev(hdev);
+		hci_free_dev(hdev);
+		h_adapter->hdev = NULL;
+	}
+
+	kfree(h_adapter);
+}
+
+const struct rsi_mod_ops rsi_bt_ops = {
+	.attach	= rsi_hci_attach,
+	.detach	= rsi_hci_detach,
+	.recv_pkt = rsi_hci_recv_pkt,
+};
+EXPORT_SYMBOL(rsi_bt_ops);
+
+static int rsi_91x_bt_module_init(void)
+{
+	return 0;
+}
+
+static void rsi_91x_bt_module_exit(void)
+{
+	return;
+}
+
+module_init(rsi_91x_bt_module_init);
+module_exit(rsi_91x_bt_module_exit);
+MODULE_AUTHOR("Redpine Signals Inc");
+MODULE_DESCRIPTION("RSI BT driver");
+MODULE_SUPPORTED_DEVICE("RSI-BT");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/include/linux/rsi_header.h b/include/linux/rsi_header.h
index 737ab4e..040f07b 100644
--- a/include/linux/rsi_header.h
+++ b/include/linux/rsi_header.h
@@ -49,6 +49,8 @@ struct rsi_proto_ops {
 struct rsi_mod_ops {
 	int (*attach)(void *priv, struct rsi_proto_ops *ops);
 	void (*detach)(void *priv);
-	int (*recv_pkt)(void *priv, u8 *msg);
+	int (*recv_pkt)(void *priv, const u8 *msg);
 };
+
+extern const struct rsi_mod_ops rsi_bt_ops;
 #endif
-- 
2.7.4