Bluetooth: btbcm: Support pcm configuration

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@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

drivers/bluetooth/btbcm.c

@@ -107,6 +107,52 @@ 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 *params)
+{
+	struct sk_buff *skb;
+	int err = 0;
+
+	skb = __hci_cmd_sync(hdev, 0xfc1d, 0, NULL, 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->len != 6 || skb->data[0]) {
+		bt_dev_err(hdev, "BCM: Read PCM int params length mismatch");
+		kfree_skb(skb);
+		return -EIO;
+	}
+
+	if (params)
+		memcpy(params, skb->data + 1, 5);
+
+	kfree_skb(skb);
+
+	return 0;
+}
+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 *params)
+{
+	struct sk_buff *skb;
+	int err;
+
+	skb = __hci_cmd_sync(hdev, 0xfc1c, 5, 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;

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 *params);
+int btbcm_write_pcm_int_params(struct hci_dev *hdev,
+			       const struct bcm_set_pcm_int_params *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 *params)
+{
+	return -EOPNOTSUPP;
+}
+
+int btbcm_write_pcm_int_params(struct hci_dev *hdev,
+			       const struct bcm_set_pcm_int_params *params)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int btbcm_patchram(struct hci_dev *hdev, const struct firmware *fw)
 {
 	return -EOPNOTSUPP;