Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990

Add support to set voltage/current of various regulators
to power up/down Bluetooth chip wcn3990.

Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btqca.h

@@ -37,6 +37,9 @@
 #define EDL_TAG_ID_HCI			(17)
 #define EDL_TAG_ID_DEEP_SLEEP		(27)
 
+#define QCA_WCN3990_POWERON_PULSE	0xFC
+#define QCA_WCN3990_POWEROFF_PULSE	0xC0
+
 enum qca_bardrate {
 	QCA_BAUDRATE_115200 	= 0,
 	QCA_BAUDRATE_57600,

drivers/bluetooth/hci_qca.c

@@ -5,7 +5,7 @@
  *  protocol extension to H4.
  *
  *  Copyright (C) 2007 Texas Instruments, Inc.
- *  Copyright (c) 2010, 2012 The Linux Foundation. All rights reserved.
+ *  Copyright (c) 2010, 2012, 2018 The Linux Foundation. All rights reserved.
  *
  *  Acknowledgements:
  *  This file is based on hci_ll.c, which was...
@@ -31,9 +31,14 @@
 #include <linux/kernel.h>
 #include <linux/clk.h>
 #include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/device.h>
 #include <linux/gpio/consumer.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/serdev.h>
 
 #include <net/bluetooth/bluetooth.h>
@@ -124,12 +129,46 @@ enum qca_speed_type {
 	QCA_OPER_SPEED
 };
 
+/*
+ * Voltage regulator information required for configuring the
+ * QCA Bluetooth chipset
+ */
+struct qca_vreg {
+	const char *name;
+	unsigned int min_uV;
+	unsigned int max_uV;
+	unsigned int load_uA;
+};
+
+struct qca_vreg_data {
+	enum qca_btsoc_type soc_type;
+	struct qca_vreg *vregs;
+	size_t num_vregs;
+};
+
+/*
+ * Platform data for the QCA Bluetooth power driver.
+ */
+struct qca_power {
+	struct device *dev;
+	const struct qca_vreg_data *vreg_data;
+	struct regulator_bulk_data *vreg_bulk;
+	bool vregs_on;
+};
+
 struct qca_serdev {
 	struct hci_uart	 serdev_hu;
 	struct gpio_desc *bt_en;
 	struct clk	 *susclk;
+	enum qca_btsoc_type btsoc_type;
+	struct qca_power *bt_power;
+	u32 init_speed;
+	u32 oper_speed;
 };
 
+static int qca_power_setup(struct hci_uart *hu, bool on);
+static void qca_power_shutdown(struct hci_dev *hdev);
+
 static void __serial_clock_on(struct tty_struct *tty)
 {
 	/* TODO: Some chipset requires to enable UART clock on client
@@ -407,6 +446,7 @@ static int qca_open(struct hci_uart *hu)
 {
 	struct qca_serdev *qcadev;
 	struct qca_data *qca;
+	int ret;
 
 	BT_DBG("hu %p qca_open", hu);
 
@@ -458,19 +498,32 @@ static int qca_open(struct hci_uart *hu)
 
 	hu->priv = qca;
 
+	if (hu->serdev) {
+		serdev_device_open(hu->serdev);
+
+		qcadev = serdev_device_get_drvdata(hu->serdev);
+		if (qcadev->btsoc_type != QCA_WCN3990) {
+			gpiod_set_value_cansleep(qcadev->bt_en, 1);
+		} else {
+			hu->init_speed = qcadev->init_speed;
+			hu->oper_speed = qcadev->oper_speed;
+			ret = qca_power_setup(hu, true);
+			if (ret) {
+				destroy_workqueue(qca->workqueue);
+				kfree_skb(qca->rx_skb);
+				hu->priv = NULL;
+				kfree(qca);
+				return ret;
+			}
+		}
+	}
+
 	timer_setup(&qca->wake_retrans_timer, hci_ibs_wake_retrans_timeout, 0);
 	qca->wake_retrans = IBS_WAKE_RETRANS_TIMEOUT_MS;
 
 	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);
 
@@ -554,10 +607,13 @@ static int qca_close(struct hci_uart *hu)
 	qca->hu = NULL;
 
 	if (hu->serdev) {
-		serdev_device_close(hu->serdev);
-
 		qcadev = serdev_device_get_drvdata(hu->serdev);
+		if (qcadev->btsoc_type == QCA_WCN3990)
+			qca_power_shutdown(hu->hdev);
+		else
 			gpiod_set_value_cansleep(qcadev->bt_en, 0);
+
+		serdev_device_close(hu->serdev);
 	}
 
 	kfree_skb(qca->rx_skb);
@@ -891,6 +947,7 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate)
 	struct hci_uart *hu = hci_get_drvdata(hdev);
 	struct qca_data *qca = hu->priv;
 	struct sk_buff *skb;
+	struct qca_serdev *qcadev;
 	u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 };
 
 	if (baudrate > QCA_BAUDRATE_3200000)
@@ -904,6 +961,13 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate)
 		return -ENOMEM;
 	}
 
+	/* Disabling hardware flow control is mandatory while
+	 * sending change baudrate request to wcn3990 SoC.
+	 */
+	qcadev = serdev_device_get_drvdata(hu->serdev);
+	if (qcadev->btsoc_type == QCA_WCN3990)
+		hci_uart_set_flow_control(hu, true);
+
 	/* Assign commands to change baudrate and packet type. */
 	skb_put_data(skb, cmd, sizeof(cmd));
 	hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;
@@ -919,6 +983,9 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate)
 	schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS));
 	set_current_state(TASK_RUNNING);
 
+	if (qcadev->btsoc_type == QCA_WCN3990)
+		hci_uart_set_flow_control(hu, false);
+
 	return 0;
 }
 
@@ -930,6 +997,43 @@ static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed)
 		hci_uart_set_baudrate(hu, speed);
 }
 
+static int qca_send_power_pulse(struct hci_dev *hdev, u8 cmd)
+{
+	struct hci_uart *hu = hci_get_drvdata(hdev);
+	struct qca_data *qca = hu->priv;
+	struct sk_buff *skb;
+
+	/* These power pulses are single byte command which are sent
+	 * at required baudrate to wcn3990. On wcn3990, we have an external
+	 * circuit at Tx pin which decodes the pulse sent at specific baudrate.
+	 * For example, wcn3990 supports RF COEX antenna for both Wi-Fi/BT
+	 * and also we use the same power inputs to turn on and off for
+	 * Wi-Fi/BT. Powering up the power sources will not enable BT, until
+	 * we send a power on pulse at 115200 bps. This algorithm will help to
+	 * save power. Disabling hardware flow control is mandatory while
+	 * sending power pulses to SoC.
+	 */
+	bt_dev_dbg(hdev, "sending power pulse %02x to SoC", cmd);
+
+	skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hci_uart_set_flow_control(hu, true);
+
+	skb_put_u8(skb, cmd);
+	hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;
+
+	skb_queue_tail(&qca->txq, skb);
+	hci_uart_tx_wakeup(hu);
+
+	/* Wait for 100 uS for SoC to settle down */
+	usleep_range(100, 200);
+	hci_uart_set_flow_control(hu, false);
+
+	return 0;
+}
+
 static unsigned int qca_get_speed(struct hci_uart *hu,
 				  enum qca_speed_type speed_type)
 {
@@ -952,9 +1056,18 @@ static unsigned int qca_get_speed(struct hci_uart *hu,
 
 static int qca_check_speeds(struct hci_uart *hu)
 {
+	struct qca_serdev *qcadev;
+
+	qcadev = serdev_device_get_drvdata(hu->serdev);
+	if (qcadev->btsoc_type == QCA_WCN3990) {
+		if (!qca_get_speed(hu, QCA_INIT_SPEED) &&
+		    !qca_get_speed(hu, QCA_OPER_SPEED))
+			return -EINVAL;
+	} else {
 		if (!qca_get_speed(hu, QCA_INIT_SPEED) ||
 		    !qca_get_speed(hu, QCA_OPER_SPEED))
 			return -EINVAL;
+	}
 
 	return 0;
 }
@@ -974,7 +1087,7 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type)
 			return 0;
 
 		qca_baudrate = qca_get_baudrate_value(speed);
-		bt_dev_info(hu->hdev, "Set UART speed to %d", speed);
+		bt_dev_dbg(hu->hdev, "Set UART speed to %d", speed);
 		ret = qca_set_baudrate(hu->hdev, qca_baudrate);
 		if (ret)
 			return ret;
@@ -985,15 +1098,52 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type)
 	return 0;
 }
 
+static int qca_wcn3990_init(struct hci_uart *hu)
+{
+	struct hci_dev *hdev = hu->hdev;
+	int ret;
+
+	/* Forcefully enable wcn3990 to enter in to boot mode. */
+	host_set_baudrate(hu, 2400);
+	ret = qca_send_power_pulse(hdev, QCA_WCN3990_POWEROFF_PULSE);
+	if (ret)
+		return ret;
+
+	qca_set_speed(hu, QCA_INIT_SPEED);
+	ret = qca_send_power_pulse(hdev, QCA_WCN3990_POWERON_PULSE);
+	if (ret)
+		return ret;
+
+	/* Wait for 100 ms for SoC to boot */
+	msleep(100);
+
+	/* Now the device is in ready state to communicate with host.
+	 * To sync host with device we need to reopen port.
+	 * Without this, we will have RTS and CTS synchronization
+	 * issues.
+	 */
+	serdev_device_close(hu->serdev);
+	ret = serdev_device_open(hu->serdev);
+	if (ret) {
+		bt_dev_err(hu->hdev, "failed to open port");
+		return ret;
+	}
+
+	hci_uart_set_flow_control(hu, false);
+
+	return 0;
+}
+
 static int qca_setup(struct hci_uart *hu)
 {
 	struct hci_dev *hdev = hu->hdev;
 	struct qca_data *qca = hu->priv;
 	unsigned int speed, qca_baudrate = QCA_BAUDRATE_115200;
+	struct qca_serdev *qcadev;
 	int ret;
 	int soc_ver = 0;
 
-	bt_dev_info(hdev, "ROME setup");
+	qcadev = serdev_device_get_drvdata(hu->serdev);
 
 	ret = qca_check_speeds(hu);
 	if (ret)
@@ -1002,8 +1152,19 @@ static int qca_setup(struct hci_uart *hu)
 	/* Patch downloading has to be done without IBS mode */
 	clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
 
-	/* Setup initial baudrate */
+	if (qcadev->btsoc_type == QCA_WCN3990) {
+		bt_dev_info(hdev, "setting up wcn3990");
+		ret = qca_wcn3990_init(hu);
+		if (ret)
+			return ret;
+
+		ret = qca_read_soc_version(hdev, &soc_ver);
+		if (ret)
+			return ret;
+	} else {
+		bt_dev_info(hdev, "ROME setup");
 		qca_set_speed(hu, QCA_INIT_SPEED);
+	}
 
 	/* Setup user speed if needed */
 	speed = qca_get_speed(hu, QCA_OPER_SPEED);
@@ -1015,15 +1176,16 @@ static int qca_setup(struct hci_uart *hu)
 		qca_baudrate = qca_get_baudrate_value(speed);
 	}
 
+	if (qcadev->btsoc_type != QCA_WCN3990) {
 		/* Get QCA version information */
 		ret = qca_read_soc_version(hdev, &soc_ver);
 		if (ret)
 			return ret;
+	}
 
 	bt_dev_info(hdev, "QCA controller version 0x%08x", soc_ver);
-
 	/* Setup patch / NVM configurations */
-	ret = qca_uart_setup(hdev, qca_baudrate, QCA_ROME, soc_ver);
+	ret = qca_uart_setup(hdev, qca_baudrate, qcadev->btsoc_type, soc_ver);
 	if (!ret) {
 		set_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
 		qca_debugfs_init(hdev);
@@ -1059,9 +1221,123 @@ static struct hci_uart_proto qca_proto = {
 	.dequeue	= qca_dequeue,
 };
 
+static const struct qca_vreg_data qca_soc_data = {
+	.soc_type = QCA_WCN3990,
+	.vregs = (struct qca_vreg []) {
+		{ "vddio",   1800000, 1900000,  15000  },
+		{ "vddxo",   1800000, 1900000,  80000  },
+		{ "vddrf",   1300000, 1350000,  300000 },
+		{ "vddch0",  3300000, 3400000,  450000 },
+	},
+	.num_vregs = 4,
+};
+
+static void qca_power_shutdown(struct hci_dev *hdev)
+{
+	struct hci_uart *hu = hci_get_drvdata(hdev);
+
+	host_set_baudrate(hu, 2400);
+	qca_send_power_pulse(hdev, QCA_WCN3990_POWEROFF_PULSE);
+	qca_power_setup(hu, false);
+}
+
+static int qca_enable_regulator(struct qca_vreg vregs,
+				struct regulator *regulator)
+{
+	int ret;
+
+	ret = regulator_set_voltage(regulator, vregs.min_uV,
+				    vregs.max_uV);
+	if (ret)
+		return ret;
+
+	if (vregs.load_uA)
+		ret = regulator_set_load(regulator,
+					 vregs.load_uA);
+
+	if (ret)
+		return ret;
+
+	return regulator_enable(regulator);
+
+}
+
+static void qca_disable_regulator(struct qca_vreg vregs,
+				  struct regulator *regulator)
+{
+	regulator_disable(regulator);
+	regulator_set_voltage(regulator, 0, vregs.max_uV);
+	if (vregs.load_uA)
+		regulator_set_load(regulator, 0);
+
+}
+
+static int qca_power_setup(struct hci_uart *hu, bool on)
+{
+	struct qca_vreg *vregs;
+	struct regulator_bulk_data *vreg_bulk;
+	struct qca_serdev *qcadev;
+	int i, num_vregs, ret = 0;
+
+	qcadev = serdev_device_get_drvdata(hu->serdev);
+	if (!qcadev || !qcadev->bt_power || !qcadev->bt_power->vreg_data ||
+	    !qcadev->bt_power->vreg_bulk)
+		return -EINVAL;
+
+	vregs = qcadev->bt_power->vreg_data->vregs;
+	vreg_bulk = qcadev->bt_power->vreg_bulk;
+	num_vregs = qcadev->bt_power->vreg_data->num_vregs;
+	BT_DBG("on: %d", on);
+	if (on && !qcadev->bt_power->vregs_on) {
+		for (i = 0; i < num_vregs; i++) {
+			ret = qca_enable_regulator(vregs[i],
+						   vreg_bulk[i].consumer);
+			if (ret)
+				break;
+		}
+
+		if (ret) {
+			BT_ERR("failed to enable regulator:%s", vregs[i].name);
+			/* turn off regulators which are enabled */
+			for (i = i - 1; i >= 0; i--)
+				qca_disable_regulator(vregs[i],
+						      vreg_bulk[i].consumer);
+		} else {
+			qcadev->bt_power->vregs_on = true;
+		}
+	} else if (!on && qcadev->bt_power->vregs_on) {
+		/* turn off regulator in reverse order */
+		i = qcadev->bt_power->vreg_data->num_vregs - 1;
+		for ( ; i >= 0; i--)
+			qca_disable_regulator(vregs[i], vreg_bulk[i].consumer);
+
+		qcadev->bt_power->vregs_on = false;
+	}
+
+	return ret;
+}
+
+static int qca_init_regulators(struct qca_power *qca,
+				const struct qca_vreg *vregs, size_t num_vregs)
+{
+	int i;
+
+	qca->vreg_bulk = devm_kzalloc(qca->dev, num_vregs *
+				      sizeof(struct regulator_bulk_data),
+				      GFP_KERNEL);
+	if (!qca->vreg_bulk)
+		return -ENOMEM;
+
+	for (i = 0; i < num_vregs; i++)
+		qca->vreg_bulk[i].supply = vregs[i].name;
+
+	return devm_regulator_bulk_get(qca->dev, num_vregs, qca->vreg_bulk);
+}
+
 static int qca_serdev_probe(struct serdev_device *serdev)
 {
 	struct qca_serdev *qcadev;
+	const struct qca_vreg_data *data;
 	int err;
 
 	qcadev = devm_kzalloc(&serdev->dev, sizeof(*qcadev), GFP_KERNEL);
@@ -1069,8 +1345,39 @@ static int qca_serdev_probe(struct serdev_device *serdev)
 		return -ENOMEM;
 
 	qcadev->serdev_hu.serdev = serdev;
+	data = of_device_get_match_data(&serdev->dev);
 	serdev_device_set_drvdata(serdev, qcadev);
+	if (data && data->soc_type == QCA_WCN3990) {
+		qcadev->btsoc_type = QCA_WCN3990;
+		qcadev->bt_power = devm_kzalloc(&serdev->dev,
+						sizeof(struct qca_power),
+						GFP_KERNEL);
+		if (!qcadev->bt_power)
+			return -ENOMEM;
 
+		qcadev->bt_power->dev = &serdev->dev;
+		qcadev->bt_power->vreg_data = data;
+		err = qca_init_regulators(qcadev->bt_power, data->vregs,
+					  data->num_vregs);
+		if (err) {
+			BT_ERR("Failed to init regulators:%d", err);
+			goto out;
+		}
+
+		qcadev->bt_power->vregs_on = false;
+
+		device_property_read_u32(&serdev->dev, "max-speed",
+					 &qcadev->oper_speed);
+		if (!qcadev->oper_speed)
+			BT_DBG("UART will pick default operating speed");
+
+		err = hci_uart_register_device(&qcadev->serdev_hu, &qca_proto);
+		if (err) {
+			BT_ERR("wcn3990 serdev registration failed");
+			goto out;
+		}
+	} else {
+		qcadev->btsoc_type = QCA_ROME;
 		qcadev->bt_en = devm_gpiod_get(&serdev->dev, "enable",
 					       GPIOD_OUT_LOW);
 		if (IS_ERR(qcadev->bt_en)) {
@@ -1095,21 +1402,27 @@ static int qca_serdev_probe(struct serdev_device *serdev)
 		err = hci_uart_register_device(&qcadev->serdev_hu, &qca_proto);
 		if (err)
 			clk_disable_unprepare(qcadev->susclk);
+	}
+
+out:	return err;
 
-	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);
+	if (qcadev->btsoc_type == QCA_WCN3990)
-
+		qca_power_shutdown(qcadev->serdev_hu.hdev);
+	else
 		clk_disable_unprepare(qcadev->susclk);
+
+	hci_uart_unregister_device(&qcadev->serdev_hu);
 }
 
 static const struct of_device_id qca_bluetooth_of_match[] = {
 	{ .compatible = "qcom,qca6174-bt" },
+	{ .compatible = "qcom,wcn3990-bt", .data = &qca_soc_data},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, qca_bluetooth_of_match);