Re: [PATCH v1] Bluetooth: hci_qca: Make bt_en and susclk not mandatory for QCA Rome

[Johan Hovold <johan@kernel.org>]

On Wed, Mar 04, 2020 at 09:54:29AM +0800, Rocky Liao wrote:
> On some platforms the bt_en pin and susclk are default on and there
> is no exposed resource to control them. This patch makes the bt_en
> and susclk not mandatory to have BT work. It also will not set the
> HCI_QUIRK_NON_PERSISTENT_SETUP and shutdown() callback if bt_en is
> not available.
> 
> Signed-off-by: Rocky Liao <rjliao@codeaurora.org>
> ---
>  drivers/bluetooth/hci_qca.c | 47 ++++++++++++++++++++-----------------
>  1 file changed, 26 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index bf436d6e638e..325baa046c3a 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -1562,9 +1562,11 @@ static int qca_power_on(struct hci_dev *hdev)
>  		ret = qca_wcn3990_init(hu);
>  	} else {
>  		qcadev = serdev_device_get_drvdata(hu->serdev);
> -		gpiod_set_value_cansleep(qcadev->bt_en, 1);
> -		/* Controller needs time to bootup. */
> -		msleep(150);
> +		if (!IS_ERR(qcadev->bt_en)) {
> +			gpiod_set_value_cansleep(qcadev->bt_en, 1);
> +			/* Controller needs time to bootup. */
> +			msleep(150);
> +		}
>  	}
>  
>  	return ret;
> @@ -1750,7 +1752,7 @@ static void qca_power_shutdown(struct hci_uart *hu)
>  		host_set_baudrate(hu, 2400);
>  		qca_send_power_pulse(hu, false);
>  		qca_regulator_disable(qcadev);
> -	} else {
> +	} else if (!IS_ERR(qcadev->bt_en)) {
>  		gpiod_set_value_cansleep(qcadev->bt_en, 0);
>  	}
>  }
> @@ -1852,6 +1854,7 @@ static int qca_serdev_probe(struct serdev_device *serdev)
>  	struct hci_dev *hdev;
>  	const struct qca_vreg_data *data;
>  	int err;
> +	bool power_ctrl_enabled = true;
>  
>  	qcadev = devm_kzalloc(&serdev->dev, sizeof(*qcadev), GFP_KERNEL);
>  	if (!qcadev)
> @@ -1901,35 +1904,37 @@ static int qca_serdev_probe(struct serdev_device *serdev)
>  		qcadev->bt_en = devm_gpiod_get(&serdev->dev, "enable",
>  					       GPIOD_OUT_LOW);

Shouldn't you use devm_gpiod_get_optional()?

>  		if (IS_ERR(qcadev->bt_en)) {
> -			dev_err(&serdev->dev, "failed to acquire enable gpio\n");
> -			return PTR_ERR(qcadev->bt_en);
> +			dev_warn(&serdev->dev, "failed to acquire enable gpio\n");
> +			power_ctrl_enabled = false;

And bail out on errors, but treat NULL as !port_ctrl_enabled?

>  		}
>  
>  		qcadev->susclk = devm_clk_get(&serdev->dev, NULL);

And devm_clk_get_optional() here.

Etc.

Also does the devicetree binding need to be updated to reflect this
change?

Johan