[PATCH v1 2/2] Bluetooth: btnxpuart: Add support for 4M baudrate

[Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx>]

This adds support for 4000000 as secondary baudrate.
This value is selected from device tree property "secondary-baudrate"
which is then used to download FW chunks, and as operational baudrate after
HCI initialization is done.

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx>
---
 drivers/bluetooth/btnxpuart.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
index 6b13feed06df..e2cd568bdffe 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);
@@ -969,9 +974,9 @@ static int nxp_recv_fw_req_v1(struct hci_dev *hdev, struct sk_buff *skb)
 			if (nxp_fw_change_baudrate(hdev, len)) {
 				nxpdev->baudrate_changed = changed;
 				serdev_device_set_baudrate(nxpdev->serdev,
-							   HCI_NXP_SEC_BAUDRATE);
+							   HCI_NXP_SEC_BAUDRATE_3M);
 				serdev_device_set_flow_control(nxpdev->serdev, true);
-				nxpdev->current_baudrate = HCI_NXP_SEC_BAUDRATE;
+				nxpdev->current_baudrate = HCI_NXP_SEC_BAUDRATE_3M;
 			}
 			goto free_skb;
 		}
@@ -992,7 +997,7 @@ 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 +1221,13 @@ 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 +1453,8 @@ 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 +1779,11 @@ 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, "secondary-baudrate",
+				 &nxpdev->secondary_baudrate);
+	if (!nxpdev->secondary_baudrate)
+		nxpdev->secondary_baudrate = HCI_NXP_SEC_BAUDRATE_3M;
+
 	set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
 
 	crc8_populate_msb(crc8_table, POLYNOMIAL8);
-- 
2.34.1