Hi Matthias,

On 2018-06-26 06:35, Matthias Kaehlcke wrote:

On Mon, Jun 25, 2018 at 07:10:13PM +0530, Balakrishna Godavarthi wrote:

quoted

Add support to set voltage/current of various regulators
to power up/down Bluetooth chip wcn3990.

Signed-off-by: Balakrishna Godavarthi <redacted>
---
changes in v8:
    * closing qca buffer, if qca_power_setup fails
    * chnaged ibs start timer function call location.
    * updated review comments.

changes in v7:
    * addressed review comments.

changes in v6:
    * Hooked up qca_power to qca_serdev.
    * renamed all the naming inconsistency functions with qca_*
    * leveraged common code of ROME for wcn3990.
    * created wrapper functions for re-usable blocks.
    * updated function of _*regulator_enable and _*regualtor_disable.
    * removed redundant comments and functions.
    * addressed review comments.

Changes in v5:
    * updated regulator vddpa min_uV to 1304000.
      * addressed review comments.

Changes in v4:
    * Segregated the changes of btqca from hci_qca
    * rebased all changes on top of bluetooth-next.
    * addressed review comments.

---

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 28187a89b850..bd4c9a78716f 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c

...
+static int qca_send_vendor_cmd(struct hci_dev *hdev, u8 cmd)
+{
+	struct hci_uart *hu = hci_get_drvdata(hdev);
+	struct qca_data *qca = hu->priv;
+	struct sk_buff *skb;
+
+	bt_dev_dbg(hdev, "sending command %02x to SoC", cmd);
+
+	skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL);
+	if (!skb) {
+		bt_dev_err(hdev, "Failed to allocate memory for vendor packet");

As mentioned on v7, custom OOM messages should be avoided.

[Bala]: sry i might have missed it, will update.

quoted

 static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type 
speed_type)
 {
+	struct qca_serdev *qcadev;
 	unsigned int speed, qca_baudrate;
 	int ret;

@@ -971,6 +1054,13 @@ static int qca_set_speed(struct hci_uart *hu, 

enum qca_speed_type speed_type)
 		return 0;
 	}

+	qcadev = serdev_device_get_drvdata(hu->serdev);
+	/* Disabling hardware flow control is preferred while
+	 * sending change baud rate command to SoC.
+	 */

Is it only preferred or must be?

[Bala]: must be. will update.

quoted

+	if (qcadev->btsoc_type == QCA_WCN3990)
+		hci_uart_set_flow_control(hu, true);
+

nit: consider doing this just before qca_set_baudrate(). It doesn't
make a difference but leaves it clearer what exactly needs to be
'protected' (analogy to locking).

[Bala] : will do it.

quoted

 	qca_baudrate = qca_get_baudrate_value(speed);
 	bt_dev_info(hu->hdev, "Set UART speed to %d", speed);
 	ret = qca_set_baudrate(hu->hdev, qca_baudrate);

@@ -980,8 +1070,10 @@ static int qca_set_speed(struct hci_uart *hu, 

enum qca_speed_type speed_type)
 	}

 	host_set_baudrate(hu, speed);
+	if (qcadev->btsoc_type == QCA_WCN3990)
+		hci_uart_set_flow_control(hu, false);

quoted

 static int qca_setup(struct hci_uart *hu)

@@ -989,10 +1081,11 @@ static int qca_setup(struct hci_uart *hu)
 	struct hci_dev *hdev = hu->hdev;
 	struct qca_data *qca = hu->priv;
 	unsigned int speed, qca_baudrate = QCA_BAUDRATE_115200;
+	struct qca_serdev *qcadev;
 	int ret;
 	int soc_ver = 0;

-	bt_dev_info(hdev, "ROME setup");
+	qcadev = serdev_device_get_drvdata(hu->serdev);

 	/* Patch downloading has to be done without IBS mode */
 	clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);

@@ -1000,6 +1093,35 @@ static int qca_setup(struct hci_uart *hu)
 	/* Setup initial baudrate */
 	qca_set_speed(hu, QCA_INIT_SPEED);

+	if (qcadev->btsoc_type == QCA_WCN3990) {
+		bt_dev_dbg(hdev, "setting up wcn3990");
+		hci_uart_set_flow_control(hu, true);
+		ret = qca_send_vendor_cmd(hdev, QCA_WCN3990_POWERON_PULSE);
+		if (ret)
+			return ret;
+
+		hci_uart_set_flow_control(hu, false);
+		serdev_device_close(hu->serdev);
+		ret = serdev_device_open(hu->serdev);
+		if (ret) {
+			bt_dev_err(hdev, "failed to open port");
+			return ret;
+		}
+
+		msleep(100);

Is the sleep really related with _open() or is it rather that the
device needs to settle after the power on pulse? In the latter case
I'd suggest to do the sleep before _open(), if it doesn't make a
functional difference (makes the code a bit more self documenting).

quoted

+		/* Setup initial baudrate */
+		qca_set_speed(hu, QCA_INIT_SPEED);
+		hci_uart_set_flow_control(hu, false);

This is still a bit noisy with all the open/close and flow control
stuff. If I understand correctly this essentially switches the
controller on (or resets it?) and brings it (and the driver) into a
sane state. Would it make sense to move the above block into a
wcn3990_init/reset() or so?

[Bala]: It is very good idea, may be future chips also will flow same 
functions with some initial setup changes.
         will group these functions into a common functions.


-- 
Regards
Balakrishna.