[PATCH v6 2/4] Bluetooth: btbcm: Support pcm configuration

[Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>]

Add BCM vendor specific command to configure PCM parameters. The new
vendor opcode allows us to set the sco routing, the pcm interface rate,
and a few other pcm specific options (frame sync, sync mode, and clock
mode). See broadcom-bluetooth.txt in Documentation for more information
about valid values for those settings.

Here is an example trace where this opcode was used to configure
a BCM4354:

        < HCI Command: Vendor (0x3f|0x001c) plen 5
                01 02 00 01 01
        > HCI Event: Command Complete (0x0e) plen 4
        Vendor (0x3f|0x001c) ncmd 1
                Status: Success (0x00)

We can read back the values as well with ocf 0x001d to confirm the
values that were set:
        $ hcitool cmd 0x3f 0x001d
        < HCI Command: ogf 0x3f, ocf 0x001d, plen 0
        > HCI Event: 0x0e plen 9
        01 1D FC 00 01 02 00 01 01

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
---

Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

 drivers/bluetooth/btbcm.c | 47 +++++++++++++++++++++++++++++++++++++++
 drivers/bluetooth/btbcm.h | 16 +++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/drivers/bluetooth/btbcm.c b/drivers/bluetooth/btbcm.c
index 2d2e6d862068..df90841d29c5 100644
--- a/drivers/bluetooth/btbcm.c
+++ b/drivers/bluetooth/btbcm.c
@@ -105,6 +105,53 @@ int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 }
 EXPORT_SYMBOL_GPL(btbcm_set_bdaddr);
 
+int btbcm_read_pcm_int_params(struct hci_dev *hdev,
+			      struct bcm_set_pcm_int_params *int_params)
+{
+	struct sk_buff *skb;
+	int err = 0;
+
+	skb = __hci_cmd_sync(hdev, 0xfc1d, 5, int_params, HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		err = PTR_ERR(skb);
+		bt_dev_err(hdev, "BCM: Read PCM int params failed (%d)", err);
+		return err;
+	}
+
+	if (!skb->data[0] && skb->len == sizeof(*int_params) + 1) {
+		memcpy(int_params, &skb->data[1], sizeof(*int_params));
+	} else {
+		bt_dev_err(hdev,
+			   "BCM: Read PCM int params failed (%d), Length (%d)",
+			   skb->data[0], skb->len);
+		err = -EINVAL;
+	}
+
+	kfree_skb(skb);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(btbcm_read_pcm_int_params);
+
+int btbcm_write_pcm_int_params(struct hci_dev *hdev,
+			       const struct bcm_set_pcm_int_params *int_params)
+{
+	struct sk_buff *skb;
+	int err;
+
+	/* Vendor ocf 0x001c sets the pcm parameters and 0x001d reads it */
+	skb = __hci_cmd_sync(hdev, 0xfc1c, 5, int_params, HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		err = PTR_ERR(skb);
+		bt_dev_err(hdev, "BCM: Write PCM int params failed (%d)", err);
+		return err;
+	}
+	kfree_skb(skb);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(btbcm_write_pcm_int_params);
+
 int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw)
 {
 	const struct hci_command_hdr *cmd;
diff --git a/drivers/bluetooth/btbcm.h b/drivers/bluetooth/btbcm.h
index d204be8a84bf..29ca3956ea1c 100644
--- a/drivers/bluetooth/btbcm.h
+++ b/drivers/bluetooth/btbcm.h
@@ -54,6 +54,10 @@ struct bcm_set_pcm_format_params {
 int btbcm_check_bdaddr(struct hci_dev *hdev);
 int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr);
 int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw);
+int btbcm_read_pcm_int_params(struct hci_dev *hdev,
+			      struct bcm_set_pcm_int_params *int_params);
+int btbcm_write_pcm_int_params(struct hci_dev *hdev,
+			       const struct bcm_set_pcm_int_params *int_params);
 
 int btbcm_setup_patchram(struct hci_dev *hdev);
 int btbcm_setup_apple(struct hci_dev *hdev);
@@ -74,6 +78,18 @@ static inline int btbcm_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
 	return -EOPNOTSUPP;
 }
 
+int btbcm_read_pcm_int_params(struct hci_dev *hdev,
+			      struct bcm_set_pcm_int_params *int_params)
+{
+	return -EOPNOTSUPP;
+}
+
+int btbcm_write_pcm_int_params(struct hci_dev *hdev,
+			       const struct bcm_set_pcm_int_params *int_params)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw)
 {
 	return -EOPNOTSUPP;
-- 
2.24.0.432.g9d3f5f5b63-goog