[PATCH v6 0/3] Bluetooth: hci_qca: Add serdev support

[PATCH v6 0/3] Bluetooth: hci_qca: Add serdev support

[Thierry Escande]

Hi,

This patchset enables the Qualcomm BT controller QCA6174 node in the
device tree of the db820c board. This allows the bluetooth chipset to
be probed and registered against the hci layer by using the serdev
framework.

This patchset also contains the documentation for the compatible
string "qcom,qca6174-bt" related to this chipset.

v6:
- Move pinctrl properties into subnodes
- fix binding documentation

v5:
- Rename 'bt-disable-n' gpio as 'enable'

v4:
- Fix dt binding documentation
- Address some other issues in patch #3

v3:
- Address comments for patch #3 (details in patch)

v2:
- Fix author email

Thierry Escande (3):
  arm64: dts: apq8096-db820c: enable bluetooth node
  dt-bindings: net: bluetooth: Add qualcomm-bluetooth
  Bluetooth: hci_qca: Add serdev support

 .../devicetree/bindings/net/qualcomm-bluetooth.txt |  34 +++++++
 arch/arm64/boot/dts/qcom/apq8096-db820c-pins.dtsi  |  26 +++++
 .../boot/dts/qcom/apq8096-db820c-pmic-pins.dtsi    |  21 ++++
 arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi       |  33 +++++++
 arch/arm64/boot/dts/qcom/msm8996.dtsi              |  10 ++
 drivers/bluetooth/Kconfig                          |   1 +
 drivers/bluetooth/hci_qca.c                        | 109 ++++++++++++++++++++-
 7 files changed, 232 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt

-- 
2.14.1

[PATCH v6 1/3] arm64: dts: apq8096-db820c: enable bluetooth node

[Thierry Escande]

Add a new serial node for the Qualcomm BT controller QCA6174. This
allows automatic probing and hci registration through the serdev
framework instead of relying on the userspace helpers.

Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
---

v6
- Move gpio properties into pinconf subnode
- move pinmux properties into mux and config subnodes

v5:
- Rename 'bt-disable-n' gpio as 'enable'

v4: no change
v3: no change

v2:
- Fix author email

 arch/arm64/boot/dts/qcom/apq8096-db820c-pins.dtsi  | 26 +++++++++++++++++
 .../boot/dts/qcom/apq8096-db820c-pmic-pins.dtsi    | 21 ++++++++++++++
 arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi       | 33 ++++++++++++++++++++++
 arch/arm64/boot/dts/qcom/msm8996.dtsi              | 10 +++++++
 4 files changed, 90 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/apq8096-db820c-pins.dtsi b/arch/arm64/boot/dts/qcom/apq8096-db820c-pins.dtsi
index 24552f19b3fa..6a573875d45a 100644
--- a/arch/arm64/boot/dts/qcom/apq8096-db820c-pins.dtsi
+++ b/arch/arm64/boot/dts/qcom/apq8096-db820c-pins.dtsi
@@ -36,4 +36,30 @@
 			drive-strength = <2>;	/* 2 MA */
 		};
 	};
+
+	blsp1_uart1_default: blsp1_uart1_default {
+		mux {
+			pins = "gpio41", "gpio42", "gpio43", "gpio44";
+			function = "blsp_uart2";
+		};
+
+		config {
+			pins = "gpio41", "gpio42", "gpio43", "gpio44";
+			drive-strength = <16>;
+			bias-disable;
+		};
+	};
+
+	blsp1_uart1_sleep: blsp1_uart1_sleep {
+		mux {
+			pins = "gpio41", "gpio42", "gpio43", "gpio44";
+			function = "gpio";
+		};
+
+		config {
+			pins = "gpio41", "gpio42", "gpio43", "gpio44";
+			drive-strength = <2>;
+			bias-disable;
+		};
+	};
 };
diff --git a/arch/arm64/boot/dts/qcom/apq8096-db820c-pmic-pins.dtsi b/arch/arm64/boot/dts/qcom/apq8096-db820c-pmic-pins.dtsi
index 59b29ddfb6e9..0a8cf7e5974f 100644
--- a/arch/arm64/boot/dts/qcom/apq8096-db820c-pmic-pins.dtsi
+++ b/arch/arm64/boot/dts/qcom/apq8096-db820c-pmic-pins.dtsi
@@ -26,6 +26,27 @@
 		};
 	};
 
+	divclk4_pin_a: divclk4 {
+		pinconf {
+			pins = "gpio18";
+			function = PMIC_GPIO_FUNC_FUNC2;
+
+			bias-disable;
+			power-source = <PM8994_GPIO_S4>;
+		};
+	};
+
+	bt_en_pin_a: bt-en-active {
+		pinconf {
+			pins = "gpio19";
+			function = PMIC_GPIO_FUNC_NORMAL;
+
+			output-low;
+			power-source = <PM8994_GPIO_S4>; // 1.8V
+			qcom,drive-strength = <PMIC_GPIO_STRENGTH_LOW>;
+		};
+	};
+
 	usb3_vbus_det_gpio: pm8996_gpio22 {
 		pinconf {
 			pins = "gpio22";
diff --git a/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi b/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi
index 1c8f1b86472d..8b3bcdf0d718 100644
--- a/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi
+++ b/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi
@@ -23,6 +23,7 @@
 	aliases {
 		serial0 = &blsp2_uart1;
 		serial1 = &blsp2_uart2;
+		serial2 = &blsp1_uart1;
 		i2c0	= &blsp1_i2c2;
 		i2c1	= &blsp2_i2c1;
 		i2c2	= &blsp2_i2c0;
@@ -34,7 +35,39 @@
 		stdout-path = "serial0:115200n8";
 	};
 
+	clocks {
+		divclk4: divclk4 {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <32768>;
+			clock-output-names = "divclk4";
+
+			pinctrl-names = "default";
+			pinctrl-0 = <&divclk4_pin_a>;
+		};
+	};
+
 	soc {
+		serial@7570000 {
+			label = "BT-UART";
+			status = "okay";
+			pinctrl-names = "default", "sleep";
+			pinctrl-0 = <&blsp1_uart1_default>;
+			pinctrl-1 = <&blsp1_uart1_sleep>;
+
+			bluetooth {
+				compatible = "qcom,qca6174-bt";
+
+				/* bt_disable_n gpio */
+				enable-gpios = <&pm8994_gpios 19 GPIO_ACTIVE_HIGH>;
+
+				pinctrl-names = "default";
+				pinctrl-0 = <&bt_en_pin_a>;
+
+				clocks = <&divclk4>;
+			};
+		};
+
 		serial@75b0000 {
 			label = "LS-UART1";
 			status = "okay";
diff --git a/arch/arm64/boot/dts/qcom/msm8996.dtsi b/arch/arm64/boot/dts/qcom/msm8996.dtsi
index 0a6f7952bbb1..2d54a86a027f 100644
--- a/arch/arm64/boot/dts/qcom/msm8996.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8996.dtsi
@@ -408,6 +408,16 @@
 			#clock-cells = <1>;
 		};
 
+		blsp1_uart1: serial@7570000 {
+			compatible = "qcom,msm-uartdm-v1.4", "qcom,msm-uartdm";
+			reg = <0x07570000 0x1000>;
+			interrupts = <GIC_SPI 108 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&gcc GCC_BLSP1_UART2_APPS_CLK>,
+				 <&gcc GCC_BLSP1_AHB_CLK>;
+			clock-names = "core", "iface";
+			status = "disabled";
+		};
+
 		blsp1_spi0: spi@7575000 {
 			compatible = "qcom,spi-qup-v2.2.1";
 			reg = <0x07575000 0x600>;
-- 
2.14.1

[PATCH v6 2/3] dt-bindings: net: bluetooth: Add qualcomm-bluetooth

[Thierry Escande]

Add binding document for serial bluetooth chips using Qualcomm protocol.

Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---

v6:
- Remove chip specific pinctrl conf
- Move gpio and clocks into optional props section

v5:
- Rename 'bt-disable-n' gpio as 'enable'

v4:
- Move bt-disable-n-gpios to required properties section
- Add clocks and pinctrl-0 as required properties

v3: no change
v2: no change

 .../devicetree/bindings/net/qualcomm-bluetooth.txt | 30 ++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt

diff --git a/Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt b/Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt
new file mode 100644
index 000000000000..f1ca8f667a5e
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt
@@ -0,0 +1,30 @@
+Qualcomm Bluetooth Chips
+---------------------
+
+This documents the binding structure and common properties for serial
+attached Qualcomm devices.
+
+Serial attached Qualcomm devices shall be a child node of the host UART
+device the slave device is attached to.
+
+Required properties:
+ - compatible: should contain one of the following:
+   * "qcom,qca6174-bt"
+
+Optional properties:
+ - enable-gpios: gpio specifier used to enable chip
+ - clocks: clock provided to the controler (SUSCLK_32KHZ)
+
+Example:
+
+serial@7570000 {
+	label = "BT-UART";
+	status = "okay";
+
+	bluetooth {
+		compatible = "qcom,qca6174-bt";
+
+		enable-gpios = <&pm8994_gpios 19 GPIO_ACTIVE_HIGH>;
+		clocks = <&divclk4>;
+	};
+};
-- 
2.14.1

[PATCH v6 3/3] Bluetooth: hci_qca: Add serdev support

[Thierry Escande]

Add support for Qualcomm serial slave devices. Probe the serial device,
retrieve its maximum speed and register a new hci uart device.

Signed-off-by: Thierry Escande <thierry.escande@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---

v6:
- Fix gpio name in error message

v5:
- Use gpio new name 'enable'

v4:
- Rename divclk4 as susclk (its name in the bt chip)
- Use gpiod_set_value_cansleep()
- Replace #include <linux/of.h> with <linux/mod_devicetable.h>
- Restore dependency on BT_HCIUART

v3:
- Remove redundant call to gpiod_set_value() after devm_gpiod_get()
- Check returned values for clk_set_rate() and clk_prepare_enable()
- Use clk_disable_unprepare()

v2:
- Fix author email

 drivers/bluetooth/Kconfig   |   1 +
 drivers/bluetooth/hci_qca.c | 109 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 108 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 07e55cd8f8c8..e0f1a6609b68 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -196,6 +196,7 @@ config BT_HCIUART_BCM
 config BT_HCIUART_QCA
 	bool "Qualcomm Atheros protocol support"
 	depends on BT_HCIUART
+	depends on BT_HCIUART_SERDEV
 	select BT_HCIUART_H4
 	select BT_QCA
 	help
diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 05ec530b8a3a..1c4475d0707c 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -29,7 +29,11 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/clk.h>
 #include <linux/debugfs.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/serdev.h>
 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
@@ -50,6 +54,9 @@
 #define IBS_TX_IDLE_TIMEOUT_MS		2000
 #define BAUDRATE_SETTLE_TIMEOUT_MS	300
 
+/* susclk rate */
+#define SUSCLK_RATE_32KHZ	32768
+
 /* HCI_IBS transmit side sleep protocol states */
 enum tx_ibs_states {
 	HCI_IBS_TX_ASLEEP,
@@ -111,6 +118,12 @@ struct qca_data {
 	u64 votes_off;
 };
 
+struct qca_serdev {
+	struct hci_uart	 serdev_hu;
+	struct gpio_desc *bt_en;
+	struct clk	 *susclk;
+};
+
 static void __serial_clock_on(struct tty_struct *tty)
 {
 	/* TODO: Some chipset requires to enable UART clock on client
@@ -386,6 +399,7 @@ static void hci_ibs_wake_retrans_timeout(struct timer_list *t)
 /* Initialize protocol */
 static int qca_open(struct hci_uart *hu)
 {
+	struct qca_serdev *qcadev;
 	struct qca_data *qca;
 
 	BT_DBG("hu %p qca_open", hu);
@@ -444,6 +458,13 @@ static int qca_open(struct hci_uart *hu)
 	timer_setup(&qca->tx_idle_timer, hci_ibs_tx_idle_timeout, 0);
 	qca->tx_idle_delay = IBS_TX_IDLE_TIMEOUT_MS;
 
+	if (hu->serdev) {
+		serdev_device_open(hu->serdev);
+
+		qcadev = serdev_device_get_drvdata(hu->serdev);
+		gpiod_set_value_cansleep(qcadev->bt_en, 1);
+	}
+
 	BT_DBG("HCI_UART_QCA open, tx_idle_delay=%u, wake_retrans=%u",
 	       qca->tx_idle_delay, qca->wake_retrans);
 
@@ -512,6 +533,7 @@ static int qca_flush(struct hci_uart *hu)
 /* Close protocol */
 static int qca_close(struct hci_uart *hu)
 {
+	struct qca_serdev *qcadev;
 	struct qca_data *qca = hu->priv;
 
 	BT_DBG("hu %p qca close", hu);
@@ -525,6 +547,13 @@ static int qca_close(struct hci_uart *hu)
 	destroy_workqueue(qca->workqueue);
 	qca->hu = NULL;
 
+	if (hu->serdev) {
+		serdev_device_close(hu->serdev);
+
+		qcadev = serdev_device_get_drvdata(hu->serdev);
+		gpiod_set_value_cansleep(qcadev->bt_en, 0);
+	}
+
 	kfree_skb(qca->rx_skb);
 
 	hu->priv = NULL;
@@ -885,6 +914,14 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate)
 	return 0;
 }
 
+static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed)
+{
+	if (hu->serdev)
+		serdev_device_set_baudrate(hu->serdev, speed);
+	else
+		hci_uart_set_baudrate(hu, speed);
+}
+
 static int qca_setup(struct hci_uart *hu)
 {
 	struct hci_dev *hdev = hu->hdev;
@@ -905,7 +942,7 @@ static int qca_setup(struct hci_uart *hu)
 		speed = hu->proto->init_speed;
 
 	if (speed)
-		hci_uart_set_baudrate(hu, speed);
+		host_set_baudrate(hu, speed);
 
 	/* Setup user speed if needed */
 	speed = 0;
@@ -924,7 +961,7 @@ static int qca_setup(struct hci_uart *hu)
 				   ret);
 			return ret;
 		}
-		hci_uart_set_baudrate(hu, speed);
+		host_set_baudrate(hu, speed);
 	}
 
 	/* Setup patch / NVM configurations */
@@ -958,12 +995,80 @@ static struct hci_uart_proto qca_proto = {
 	.dequeue	= qca_dequeue,
 };
 
+static int qca_serdev_probe(struct serdev_device *serdev)
+{
+	struct qca_serdev *qcadev;
+	int err;
+
+	qcadev = devm_kzalloc(&serdev->dev, sizeof(*qcadev), GFP_KERNEL);
+	if (!qcadev)
+		return -ENOMEM;
+
+	qcadev->serdev_hu.serdev = serdev;
+	serdev_device_set_drvdata(serdev, qcadev);
+
+	qcadev->bt_en = devm_gpiod_get(&serdev->dev, "enable",
+				       GPIOD_OUT_LOW);
+	if (IS_ERR(qcadev->bt_en)) {
+		dev_err(&serdev->dev, "failed to acquire enable gpio\n");
+		return PTR_ERR(qcadev->bt_en);
+	}
+
+	qcadev->susclk = devm_clk_get(&serdev->dev, NULL);
+	if (IS_ERR(qcadev->susclk)) {
+		dev_err(&serdev->dev, "failed to acquire clk\n");
+		return PTR_ERR(qcadev->susclk);
+	}
+
+	err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ);
+	if (err)
+		return err;
+
+	err = clk_prepare_enable(qcadev->susclk);
+	if (err)
+		return err;
+
+	err = hci_uart_register_device(&qcadev->serdev_hu, &qca_proto);
+	if (err)
+		clk_disable_unprepare(qcadev->susclk);
+
+	return err;
+}
+
+static void qca_serdev_remove(struct serdev_device *serdev)
+{
+	struct qca_serdev *qcadev = serdev_device_get_drvdata(serdev);
+
+	hci_uart_unregister_device(&qcadev->serdev_hu);
+
+	clk_disable_unprepare(qcadev->susclk);
+}
+
+static const struct of_device_id qca_bluetooth_of_match[] = {
+	{ .compatible = "qcom,qca6174-bt" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, qca_bluetooth_of_match);
+
+static struct serdev_device_driver qca_serdev_driver = {
+	.probe = qca_serdev_probe,
+	.remove = qca_serdev_remove,
+	.driver = {
+		.name = "hci_uart_qca",
+		.of_match_table = qca_bluetooth_of_match,
+	},
+};
+
 int __init qca_init(void)
 {
+	serdev_device_driver_register(&qca_serdev_driver);
+
 	return hci_uart_register_proto(&qca_proto);
 }
 
 int __exit qca_deinit(void)
 {
+	serdev_device_driver_unregister(&qca_serdev_driver);
+
 	return hci_uart_unregister_proto(&qca_proto);
 }
-- 
2.14.1

Re: [PATCH v6 0/3] Bluetooth: hci_qca: Add serdev support

[Thierry Escande]

Hi,

On 28/03/2018 11:51, Thierry Escande wrote:
> Hi,
> 
> This patchset enables the Qualcomm BT controller QCA6174 node in the
> device tree of the db820c board. This allows the bluetooth chipset to
> be probed and registered against the hci layer by using the serdev
> framework.
> 
> This patchset also contains the documentation for the compatible
> string "qcom,qca6174-bt" related to this chipset.
> 
> v6:
> - Move pinctrl properties into subnodes
> - fix binding documentation
> 
> v5:
> - Rename 'bt-disable-n' gpio as 'enable'
> 
> v4:
> - Fix dt binding documentation
> - Address some other issues in patch #3
> 
> v3:
> - Address comments for patch #3 (details in patch)
> 
> v2:
> - Fix author email
> 
> Thierry Escande (3):
>    arm64: dts: apq8096-db820c: enable bluetooth node
>    dt-bindings: net: bluetooth: Add qualcomm-bluetooth
>    Bluetooth: hci_qca: Add serdev support
> 
>   .../devicetree/bindings/net/qualcomm-bluetooth.txt |  34 +++++++
>   arch/arm64/boot/dts/qcom/apq8096-db820c-pins.dtsi  |  26 +++++
>   .../boot/dts/qcom/apq8096-db820c-pmic-pins.dtsi    |  21 ++++
>   arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi       |  33 +++++++
>   arch/arm64/boot/dts/qcom/msm8996.dtsi              |  10 ++
>   drivers/bluetooth/Kconfig                          |   1 +
>   drivers/bluetooth/hci_qca.c                        | 109 ++++++++++++++++++++-
>   7 files changed, 232 insertions(+), 2 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/net/qualcomm-bluetooth.txt
> 

Please hold this patchset as a v7 is coming soon.

Regards,
Thierry