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From:   Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
To:     Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        Rob Herring <robh+dt@kernel.org>
Cc:     linux-bluetooth@vger.kernel.org, dianders@chromium.org,
        Abhishek Pandit-Subedi <abhishekpandit@chromium.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/4] Bluetooth: hci_bcm: Disallow set_baudrate for BCM4354
Date:   Thu,  7 Nov 2019 15:27:09 -0800
Message-Id: <20191107232713.48577-2-abhishekpandit@chromium.org>
In-Reply-To: <20191107232713.48577-1-abhishekpandit@chromium.org>
References: <20191107232713.48577-1-abhishekpandit@chromium.org>
MIME-Version: 1.0
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Sender: linux-bluetooth-owner@vger.kernel.org
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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.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v2: None

 drivers/bluetooth/hci_bcm.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 0f851c0dde7f..2114df607cb3 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -1167,7 +1167,7 @@ static int bcm_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct hci_uart_proto bcm_proto = {
+static struct hci_uart_proto bcm_proto = {
 	.id		= HCI_UART_BCM,
 	.name		= "Broadcom",
 	.manufacturer	= 15,
@@ -1371,6 +1371,24 @@ static struct platform_driver bcm_driver = {
 	},
 };
 
+#define BCM_QUIRK_DISALLOW_SET_BAUDRATE (1 << 0)
+const u32 disallow_set_baudrate = BCM_QUIRK_DISALLOW_SET_BAUDRATE;
+
+static int bcm_check_disallow_set_baudrate(struct serdev_device *serdev)
+{
+	const u32 *quirks = device_get_match_data(&serdev->dev);
+
+	if (quirks) {
+		/* BCM4354 can't run at full speed before patchram. Disallow
+		 * externally setting operating speed.
+		 */
+		if (*quirks & BCM_QUIRK_DISALLOW_SET_BAUDRATE)
+			return 1;
+	}
+
+	return 0;
+}
+
 static int bcm_serdev_probe(struct serdev_device *serdev)
 {
 	struct bcm_device *bcmdev;
@@ -1408,6 +1426,9 @@ static int bcm_serdev_probe(struct serdev_device *serdev)
 	if (err)
 		dev_err(&serdev->dev, "Failed to power down\n");
 
+	if (bcm_check_disallow_set_baudrate(serdev))
+		bcm_proto.set_baudrate = NULL;
+
 	return hci_uart_register_device(&bcmdev->serdev_hu, &bcm_proto);
 }
 
@@ -1424,7 +1445,7 @@ static const struct of_device_id bcm_bluetooth_of_match[] = {
 	{ .compatible = "brcm,bcm4345c5" },
 	{ .compatible = "brcm,bcm4330-bt" },
 	{ .compatible = "brcm,bcm43438-bt" },
-	{ .compatible = "brcm,bcm43540-bt" },
+	{ .compatible = "brcm,bcm43540-bt", .data = &disallow_set_baudrate },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, bcm_bluetooth_of_match);
-- 
2.24.0.rc1.363.gb1bccd3e3d-goog