Bluetooth: Introduce Qualcomm WCNSS SMD based HCI driver

The Qualcomm WCNSS chip provides two SMD channels to the BT core; one
for command and one for event packets. This driver exposes the two
channels as a hci device.
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/Kconfig

@@ -331,4 +331,16 @@ config BT_WILINK
 	  Say Y here to compile support for Texas Instrument's WiLink7 driver
 	  into the kernel or say M to compile it as module (btwilink).
 
+config BT_QCOMSMD
+	tristate "Qualcomm SMD based HCI support"
+	depends on QCOM_SMD
+	select BT_QCA
+	help
+	  Qualcomm SMD based HCI driver.
+	  This driver is used to bridge HCI data onto the shared memory
+	  channels to the WCNSS core.
+
+	  Say Y here to compile support for HCI over Qualcomm SMD into the
+	  kernel or say M to compile as a module.
+
 endmenu

drivers/bluetooth/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_BT_ATH3K)		+= ath3k.o
 obj-$(CONFIG_BT_MRVL)		+= btmrvl.o
 obj-$(CONFIG_BT_MRVL_SDIO)	+= btmrvl_sdio.o
 obj-$(CONFIG_BT_WILINK)		+= btwilink.o
+obj-$(CONFIG_BT_QCOMSMD)	+= btqcomsmd.o
 obj-$(CONFIG_BT_BCM)		+= btbcm.o
 obj-$(CONFIG_BT_RTL)		+= btrtl.o
 obj-$(CONFIG_BT_QCA)		+= btqca.o

drivers/bluetooth/btqcomsmd.c

+/*
+ * Copyright (c) 2016, Linaro Ltd.
+ * Copyright (c) 2015, Sony Mobile Communications Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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/module.h>
+#include <linux/slab.h>
+#include <linux/soc/qcom/smd.h>
+#include <linux/soc/qcom/wcnss_ctrl.h>
+#include <linux/platform_device.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "btqca.h"
+
+struct btqcomsmd {
+	struct hci_dev *hdev;
+
+	struct qcom_smd_channel *acl_channel;
+	struct qcom_smd_channel *cmd_channel;
+};
+
+static int btqcomsmd_recv(struct hci_dev *hdev, unsigned int type,
+			   const void *data, size_t count)
+{
+	struct sk_buff *skb;
+
+	/* Use GFP_ATOMIC as we're in IRQ context */
+	skb = bt_skb_alloc(count, GFP_ATOMIC);
+	if (!skb) {
+		hdev->stat.err_rx++;
+		return -ENOMEM;
+	}
+
+	hci_skb_pkt_type(skb) = type;
+	memcpy(skb_put(skb, count), data, count);
+
+	return hci_recv_frame(hdev, skb);
+}
+
+static int btqcomsmd_acl_callback(struct qcom_smd_channel *channel,
+				  const void *data, size_t count)
+{
+	struct btqcomsmd *btq = qcom_smd_get_drvdata(channel);
+
+	btq->hdev->stat.byte_rx += count;
+	return btqcomsmd_recv(btq->hdev, HCI_ACLDATA_PKT, data, count);
+}
+
+static int btqcomsmd_cmd_callback(struct qcom_smd_channel *channel,
+				  const void *data, size_t count)
+{
+	struct btqcomsmd *btq = qcom_smd_get_drvdata(channel);
+
+	return btqcomsmd_recv(btq->hdev, HCI_EVENT_PKT, data, count);
+}
+
+static int btqcomsmd_send(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct btqcomsmd *btq = hci_get_drvdata(hdev);
+	int ret;
+
+	switch (hci_skb_pkt_type(skb)) {
+	case HCI_ACLDATA_PKT:
+		ret = qcom_smd_send(btq->acl_channel, skb->data, skb->len);
+		hdev->stat.acl_tx++;
+		hdev->stat.byte_tx += skb->len;
+		break;
+	case HCI_COMMAND_PKT:
+		ret = qcom_smd_send(btq->cmd_channel, skb->data, skb->len);
+		hdev->stat.cmd_tx++;
+		break;
+	default:
+		ret = -EILSEQ;
+		break;
+	}
+
+	kfree_skb(skb);
+
+	return ret;
+}
+
+static int btqcomsmd_open(struct hci_dev *hdev)
+{
+	return 0;
+}
+
+static int btqcomsmd_close(struct hci_dev *hdev)
+{
+	return 0;
+}
+
+static int btqcomsmd_probe(struct platform_device *pdev)
+{
+	struct btqcomsmd *btq;
+	struct hci_dev *hdev;
+	void *wcnss;
+	int ret;
+
+	btq = devm_kzalloc(&pdev->dev, sizeof(*btq), GFP_KERNEL);
+	if (!btq)
+		return -ENOMEM;
+
+	wcnss = dev_get_drvdata(pdev->dev.parent);
+
+	btq->acl_channel = qcom_wcnss_open_channel(wcnss, "APPS_RIVA_BT_ACL",
+						   btqcomsmd_acl_callback);
+	if (IS_ERR(btq->acl_channel))
+		return PTR_ERR(btq->acl_channel);
+
+	btq->cmd_channel = qcom_wcnss_open_channel(wcnss, "APPS_RIVA_BT_CMD",
+						   btqcomsmd_cmd_callback);
+	if (IS_ERR(btq->cmd_channel))
+		return PTR_ERR(btq->cmd_channel);
+
+	qcom_smd_set_drvdata(btq->acl_channel, btq);
+	qcom_smd_set_drvdata(btq->cmd_channel, btq);
+
+	hdev = hci_alloc_dev();
+	if (!hdev)
+		return -ENOMEM;
+
+	hci_set_drvdata(hdev, btq);
+	btq->hdev = hdev;
+	SET_HCIDEV_DEV(hdev, &pdev->dev);
+
+	hdev->bus = HCI_SMD;
+	hdev->open = btqcomsmd_open;
+	hdev->close = btqcomsmd_close;
+	hdev->send = btqcomsmd_send;
+	hdev->set_bdaddr = qca_set_bdaddr_rome;
+
+	ret = hci_register_dev(hdev);
+	if (ret < 0) {
+		hci_free_dev(hdev);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, btq);
+
+	return 0;
+}
+
+static int btqcomsmd_remove(struct platform_device *pdev)
+{
+	struct btqcomsmd *btq = platform_get_drvdata(pdev);
+
+	hci_unregister_dev(btq->hdev);
+	hci_free_dev(btq->hdev);
+
+	return 0;
+}
+
+static const struct of_device_id btqcomsmd_of_match[] = {
+	{ .compatible = "qcom,wcnss-bt", },
+	{ },
+};
+
+static struct platform_driver btqcomsmd_driver = {
+	.probe = btqcomsmd_probe,
+	.remove = btqcomsmd_remove,
+	.driver  = {
+		.name  = "btqcomsmd",
+		.of_match_table = btqcomsmd_of_match,
+	},
+};
+
+module_platform_driver(btqcomsmd_driver);
+
+MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
+MODULE_DESCRIPTION("Qualcomm SMD HCI driver");
+MODULE_LICENSE("GPL v2");