> -----Original Message-----
> From: Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx>
> Sent: Wednesday, June 18, 2025 10:20 PM
> To: marcel@xxxxxxxxxxxx; luiz.dentz@xxxxxxxxx; robh@xxxxxxxxxx;
> krzk+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx
> Cc: linux-bluetooth@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; Amitkumar Karwar
> <amitkumar.karwar@xxxxxxx>; Neeraj Sanjay Kale
> <neeraj.sanjaykale@xxxxxxx>; Sherry Sun <sherry.sun@xxxxxxx>; Manjeet
> Gupta <manjeet.gupta@xxxxxxx>
> Subject: [PATCH v2 2/2] Bluetooth: btnxpuart: Add support for 4M baudrate
>
> This adds support for 4000000 as secondary baudrate.
> This value is selected from device tree property "max-speed"
> which is then used to download FW chunks, and as operational baudrate
> after HCI initialization is done.
>
> This feature is applicable for all new V3 bootloader chips and w8987 V1
> bootloader chip.
>
> This property does not apply for w8997 compatible device, since it downloads
> a helper.bin FW file that sets secondary baudrate as 3000000 only.
>
> Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx>
> ---
> v2: Change DT property to 'max-speed'. (Krzysztof)
> Add support for 4M baudrate to w8987. Update commit message.
> (Sherry)
> ---
> drivers/bluetooth/btnxpuart.c | 30 +++++++++++++++++++++---------
> 1 file changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
> index 6b13feed06df..c9b3e158f438 100644
> --- a/drivers/bluetooth/btnxpuart.c
> +++ b/drivers/bluetooth/btnxpuart.c
> @@ -73,7 +73,8 @@
> #define FW_AUTH_ENC 0xc0
>
> #define HCI_NXP_PRI_BAUDRATE 115200
> -#define HCI_NXP_SEC_BAUDRATE 3000000
> +#define HCI_NXP_SEC_BAUDRATE_3M 3000000
> +#define HCI_NXP_SEC_BAUDRATE_4M 4000000
>
> #define MAX_FW_FILE_NAME_LEN 50
>
> @@ -201,6 +202,7 @@ struct btnxpuart_dev {
> u32 new_baudrate;
> u32 current_baudrate;
> u32 fw_init_baudrate;
> + u32 secondary_baudrate;
> enum bootloader_param_change timeout_changed;
> enum bootloader_param_change baudrate_changed;
> bool helper_downloaded;
> @@ -802,7 +804,10 @@ static bool nxp_fw_change_baudrate(struct hci_dev
> *hdev, u16 req_len)
> nxpdev->fw_v3_offset_correction += req_len;
> } else if (req_len == sizeof(uart_config)) {
> uart_config.clkdiv.address = __cpu_to_le32(clkdivaddr);
> - uart_config.clkdiv.value = __cpu_to_le32(0x00c00000);
> + if (nxpdev->new_baudrate == HCI_NXP_SEC_BAUDRATE_4M)
> + uart_config.clkdiv.value =
> __cpu_to_le32(0x01000000);
> + else
> + uart_config.clkdiv.value =
> __cpu_to_le32(0x00c00000);
> uart_config.uartdiv.address = __cpu_to_le32(uartdivaddr);
> uart_config.uartdiv.value = __cpu_to_le32(1);
> uart_config.mcr.address = __cpu_to_le32(uartmcraddr); @@
> -966,12 +971,13 @@ static int nxp_recv_fw_req_v1(struct hci_dev *hdev,
> struct sk_buff *skb)
> goto free_skb;
> }
> if (nxpdev->baudrate_changed != changed) {
> + nxpdev->new_baudrate = nxpdev-
> >secondary_baudrate;
> if (nxp_fw_change_baudrate(hdev, len)) {
> nxpdev->baudrate_changed = changed;
> serdev_device_set_baudrate(nxpdev->serdev,
> -
> HCI_NXP_SEC_BAUDRATE);
> + nxpdev-
> >secondary_baudrate);
> serdev_device_set_flow_control(nxpdev-
> >serdev, true);
> - nxpdev->current_baudrate =
> HCI_NXP_SEC_BAUDRATE;
> + nxpdev->current_baudrate = nxpdev-
> >secondary_baudrate;
> }
> goto free_skb;
> }
> @@ -992,7 +998,7 @@ static int nxp_recv_fw_req_v1(struct hci_dev *hdev,
> struct sk_buff *skb)
> nxpdev->helper_downloaded = true;
> serdev_device_wait_until_sent(nxpdev->serdev, 0);
> serdev_device_set_baudrate(nxpdev->serdev,
> - HCI_NXP_SEC_BAUDRATE);
> +
> HCI_NXP_SEC_BAUDRATE_3M);
> serdev_device_set_flow_control(nxpdev->serdev,
> true);
> } else {
> clear_bit(BTNXPUART_FW_DOWNLOADING,
> &nxpdev->tx_state); @@ -1216,12 +1222,13 @@ static int
> nxp_recv_fw_req_v3(struct hci_dev *hdev, struct sk_buff *skb)
> }
>
> if (nxpdev->baudrate_changed != changed) {
> + nxpdev->new_baudrate = nxpdev->secondary_baudrate;
> if (nxp_fw_change_baudrate(hdev, len)) {
> nxpdev->baudrate_changed = cmd_sent;
> serdev_device_set_baudrate(nxpdev->serdev,
> - HCI_NXP_SEC_BAUDRATE);
> + nxpdev-
> >secondary_baudrate);
> serdev_device_set_flow_control(nxpdev->serdev,
> true);
> - nxpdev->current_baudrate =
> HCI_NXP_SEC_BAUDRATE;
> + nxpdev->current_baudrate = nxpdev-
> >secondary_baudrate;
> }
> goto free_skb;
> }
> @@ -1447,8 +1454,8 @@ static int nxp_post_init(struct hci_dev *hdev)
> struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> struct ps_data *psdata = &nxpdev->psdata;
>
> - if (nxpdev->current_baudrate != HCI_NXP_SEC_BAUDRATE) {
> - nxpdev->new_baudrate = HCI_NXP_SEC_BAUDRATE;
> + if (nxpdev->current_baudrate != nxpdev->secondary_baudrate) {
> + nxpdev->new_baudrate = nxpdev->secondary_baudrate;
> nxp_set_baudrate_cmd(hdev, NULL);
> }
> if (psdata->cur_h2c_wakeupmode != psdata->h2c_wakeupmode) @@
> -1773,6 +1780,11 @@ static int nxp_serdev_probe(struct serdev_device
> *serdev)
> if (!nxpdev->fw_init_baudrate)
> nxpdev->fw_init_baudrate = FW_INIT_BAUDRATE;
>
> + device_property_read_u32(&nxpdev->serdev->dev, "max-speed",
> + &nxpdev->secondary_baudrate);
> + if (!nxpdev->secondary_baudrate)
> + nxpdev->secondary_baudrate =
> HCI_NXP_SEC_BAUDRATE_3M;
Hi Neeraj,
Seems you missed my comment here in V1 patch, attach again.
What if the user sets the wrong secondary_baudrate/max-speed in dts (not 3M or 4M)?
Need to add the corresponding error handling here. Make sure the value is 3M or 4M, otherwise report an error.
Best Regards
Sherry
> +
> set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
>
> crc8_populate_msb(crc8_table, POLYNOMIAL8);
> --
> 2.34.1
