Hi Abhishek,
> Without updating the patchram, the BCM4354 does not support a higher
> operating speed. The normal bcm_setup follows the correct order
> (init_speed, patchram and then oper_speed) but the serdev driver will
> set the operating speed before calling the hu->setup function. Thus,
> for the BCM4354, disallow setting the operating speed before patchram.
> If set_baudrate is called before setup, it will return -EBUSY.
>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
> ---
>
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
> drivers/bluetooth/hci_bcm.c | 37 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 36 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
> index 0f851c0dde7f..6134bff58748 100644
> --- a/drivers/bluetooth/hci_bcm.c
> +++ b/drivers/bluetooth/hci_bcm.c
> @@ -47,6 +47,14 @@
>
> #define BCM_NUM_SUPPLIES 2
>
> +/**
> + * struct bcm_device_data - device specific data
> + * @no_early_set_baudrate: Disallow set baudrate before driver setup()
> + */
> +struct bcm_device_data {
> + bool no_early_set_baudrate;
> +};
> +
> /**
> * struct bcm_device - device driver resources
> * @serdev_hu: HCI UART controller struct
> @@ -79,6 +87,7 @@
> * @hu: pointer to HCI UART controller struct,
> * used to disable flow control during runtime suspend and system sleep
> * @is_suspended: whether flow control is currently disabled
> + * @disallow_set_baudrate: don't allow set_baudrate
> */
> struct bcm_device {
> /* Must be the first member, hci_serdev.c expects this. */
> @@ -112,6 +121,7 @@ struct bcm_device {
> struct hci_uart *hu;
> bool is_suspended;
> #endif
> + bool disallow_set_baudrate;
> };
call it no_early_set_baudrate here as well.
>
> /* generic bcm uart resources */
> @@ -141,9 +151,13 @@ static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed)
> static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)
> {
> struct hci_dev *hdev = hu->hdev;
> + struct bcm_data *bcm = hu->priv;
> struct sk_buff *skb;
> struct bcm_update_uart_baud_rate param;
>
> + if (bcm && bcm->dev && bcm->dev->disallow_set_baudrate)
> + return -EBUSY;
> +
> if (speed > 3000000) {
> struct bcm_write_uart_clock_setting clock;
>
> @@ -551,6 +565,12 @@ static int bcm_setup(struct hci_uart *hu)
> goto finalize;
> }
>
> + /* If we disallow early set baudrate, we can re-enable it now that
> + * patchram is done
> + */
> + if (bcm->dev && bcm->dev->disallow_set_baudrate)
> + bcm->dev->disallow_set_baudrate = false;
> +
Lets not hack a different behavior of bcm_set_baudrate that magically changes based on a bool.
Actually wouldn’t be setting hu->oper_speed to 0 have the same affect and bcm_set_baudrate will not be called after setting the init speed. We should be ensuring that in the case where we do not want the baudrate change before calling ->setup() is somehow covered in hci_ldisc directly and not hacked into the ->set_baudrate callback.
> /* Init speed if any */
> if (hu->init_speed)
> speed = hu->init_speed;
> @@ -1371,6 +1391,15 @@ static struct platform_driver bcm_driver = {
> },
> };
>
> +static void bcm_configure_device_data(struct bcm_device *bdev)
> +{
> + const struct bcm_device_data *data = device_get_match_data(bdev->dev);
> +
> + if (data) {
> + bdev->disallow_set_baudrate = data->no_early_set_baudrate;
> + }
> +}
> +
> static int bcm_serdev_probe(struct serdev_device *serdev)
> {
> struct bcm_device *bcmdev;
> @@ -1408,6 +1437,8 @@ static int bcm_serdev_probe(struct serdev_device *serdev)
> if (err)
> dev_err(&serdev->dev, "Failed to power down\n");
>
> + bcm_configure_device_data(bcmdev);
> +
I would not split this out into a separate function. Lets do this in probe() right here.
> return hci_uart_register_device(&bcmdev->serdev_hu, &bcm_proto);
> }
>
> @@ -1419,12 +1450,16 @@ static void bcm_serdev_remove(struct serdev_device *serdev)
> }
>
> #ifdef CONFIG_OF
> +struct bcm_device_data bcm4354_device_data = {
> + .no_early_set_baudrate = true,
> +};
> +
> static const struct of_device_id bcm_bluetooth_of_match[] = {
> { .compatible = "brcm,bcm20702a1" },
> { .compatible = "brcm,bcm4345c5" },
> { .compatible = "brcm,bcm4330-bt" },
> { .compatible = "brcm,bcm43438-bt" },
> - { .compatible = "brcm,bcm43540-bt" },
> + { .compatible = "brcm,bcm43540-bt", .data = &bcm4354_device_data },
> { },
> };
> MODULE_DEVICE_TABLE(of, bcm_bluetooth_of_match);
Regards
Marcel
