[PATCH v6 1/4] Bluetooth: hci_bcm: Disallow set_baudrate for BCM4354

From: Abhishek Pandit-Subedi
Date: Mon Nov 18 2019 - 14:21:43 EST


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, don't set the operating speed before patchram.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
---

Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

drivers/bluetooth/hci_bcm.c | 31 +++++++++++++++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 0f851c0dde7f..ee40003008d8 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
+ * @no_early_set_baudrate: don't set_baudrate before setup()
*/
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 no_early_set_baudrate;
};

/* generic bcm uart resources */
@@ -447,7 +457,13 @@ static int bcm_open(struct hci_uart *hu)
if (bcm->dev) {
hci_uart_set_flow_control(hu, true);
hu->init_speed = bcm->dev->init_speed;
- hu->oper_speed = bcm->dev->oper_speed;
+
+ /* If oper_speed is set, ldisc/serdev will set the baudrate
+ * before calling setup()
+ */
+ if (!bcm->dev->no_early_set_baudrate)
+ hu->oper_speed = bcm->dev->oper_speed;
+
err = bcm_gpio_set_power(bcm->dev, true);
hci_uart_set_flow_control(hu, false);
if (err)
@@ -565,6 +581,8 @@ static int bcm_setup(struct hci_uart *hu)
/* Operational speed if any */
if (hu->oper_speed)
speed = hu->oper_speed;
+ else if (bcm->dev && bcm->dev->oper_speed)
+ speed = bcm->dev->oper_speed;
else if (hu->proto->oper_speed)
speed = hu->proto->oper_speed;
else
@@ -1374,6 +1392,7 @@ static struct platform_driver bcm_driver = {
static int bcm_serdev_probe(struct serdev_device *serdev)
{
struct bcm_device *bcmdev;
+ const struct bcm_device_data *data;
int err;

bcmdev = devm_kzalloc(&serdev->dev, sizeof(*bcmdev), GFP_KERNEL);
@@ -1408,6 +1427,10 @@ static int bcm_serdev_probe(struct serdev_device *serdev)
if (err)
dev_err(&serdev->dev, "Failed to power down\n");

+ data = device_get_match_data(bcmdev->dev);
+ if (data)
+ bcmdev->no_early_set_baudrate = data->no_early_set_baudrate;
+
return hci_uart_register_device(&bcmdev->serdev_hu, &bcm_proto);
}

@@ -1419,12 +1442,16 @@ 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);
--
2.24.0.432.g9d3f5f5b63-goog