[PATCH 4/4] Bluetooth: hci_bcm: Increase host baudrate for CYW55572 in autobaud mode

From: Hakan Jansson
Date: Mon Jun 20 2022 - 08:03:18 EST


Add device specific data for max baudrate in autobaud mode. This allows the
host to use a baudrate higher than "init speed" when loading FW in autobaud
mode.

Signed-off-by: Hakan Jansson <hakan.jansson@xxxxxxxxxxxx>
---
drivers/bluetooth/hci_bcm.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 0ae627c293c5..d7e0b75db8a6 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -53,10 +53,12 @@
* struct bcm_device_data - device specific data
* @no_early_set_baudrate: Disallow set baudrate before driver setup()
* @drive_rts_on_open: drive RTS signal on ->open() when platform requires it
+ * @max_autobaud_speed: max baudrate supported by device in autobaud mode
*/
struct bcm_device_data {
bool no_early_set_baudrate;
bool drive_rts_on_open;
+ u32 max_autobaud_speed;
};

/**
@@ -100,6 +102,7 @@ struct bcm_device_data {
* @drive_rts_on_open: drive RTS signal on ->open() when platform requires it
* @pcm_int_params: keep the initial PCM configuration
* @use_autobaud_mode: start Bluetooth device in autobaud mode
+ * @max_autobaud_speed: max baudrate supported by device in autobaud mode
*/
struct bcm_device {
/* Must be the first member, hci_serdev.c expects this. */
@@ -139,6 +142,7 @@ struct bcm_device {
bool drive_rts_on_open;
bool use_autobaud_mode;
u8 pcm_int_params[5];
+ u32 max_autobaud_speed;
};

/* generic bcm uart resources */
@@ -479,7 +483,10 @@ static int bcm_open(struct hci_uart *hu)
else if (bcm->dev->drive_rts_on_open)
hci_uart_set_flow_control(hu, true);

- hu->init_speed = bcm->dev->init_speed;
+ if (bcm->dev->use_autobaud_mode && bcm->dev->max_autobaud_speed)
+ hu->init_speed = min(bcm->dev->oper_speed, bcm->dev->max_autobaud_speed);
+ else
+ hu->init_speed = bcm->dev->init_speed;

/* If oper_speed is set, ldisc/serdev will set the baudrate
* before calling setup()
@@ -585,8 +592,8 @@ static int bcm_setup(struct hci_uart *hu)
return 0;

/* Init speed if any */
- if (hu->init_speed)
- speed = hu->init_speed;
+ if (bcm->dev && bcm->dev->init_speed)
+ speed = bcm->dev->init_speed;
else if (hu->proto->init_speed)
speed = hu->proto->init_speed;
else
@@ -1519,6 +1526,7 @@ static int bcm_serdev_probe(struct serdev_device *serdev)

data = device_get_match_data(bcmdev->dev);
if (data) {
+ bcmdev->max_autobaud_speed = data->max_autobaud_speed;
bcmdev->no_early_set_baudrate = data->no_early_set_baudrate;
bcmdev->drive_rts_on_open = data->drive_rts_on_open;
}
@@ -1542,6 +1550,10 @@ static struct bcm_device_data bcm43438_device_data = {
.drive_rts_on_open = true,
};

+static struct bcm_device_data cyw55572_device_data = {
+ .max_autobaud_speed = 921600,
+};
+
static const struct of_device_id bcm_bluetooth_of_match[] = {
{ .compatible = "brcm,bcm20702a1" },
{ .compatible = "brcm,bcm4329-bt" },
@@ -1554,7 +1566,7 @@ static const struct of_device_id bcm_bluetooth_of_match[] = {
{ .compatible = "brcm,bcm4349-bt", .data = &bcm43438_device_data },
{ .compatible = "brcm,bcm43540-bt", .data = &bcm4354_device_data },
{ .compatible = "brcm,bcm4335a0" },
- { .compatible = "infineon,cyw55572-bt" },
+ { .compatible = "infineon,cyw55572-bt", .data = &cyw55572_device_data },
{ },
};
MODULE_DEVICE_TABLE(of, bcm_bluetooth_of_match);
--
2.25.1