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>

2 files changed, 363 insertions, 47 deletions

diff --git a/drivers/bluetooth/btqca.h b/drivers/bluetooth/btqca.h
index a9c2779f3e07..0c01f375fe83 100644
--- a/drivers/bluetooth/btqca.h
+++ b/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,
diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 29adb95f0957..e182f6019f68 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/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;
 
-        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);
+                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;
+
         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);
-                gpiod_set_value_cansleep(qcadev->bt_en, 0);
+                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)
 {
-        if (!qca_get_speed(hu, QCA_INIT_SPEED) ||
-            !qca_get_speed(hu, QCA_OPER_SPEED))
-                return -EINVAL;
+        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 */
-        qca_set_speed(hu, QCA_INIT_SPEED);
+        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);
         }
 
-        /* Get QCA version information */
-        ret = qca_read_soc_version(hdev, &soc_ver);
-        if (ret)
-                return ret;
+        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);
@@ -1069,47 +1345,84 @@ 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_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->bt_power->vregs_on = false;
 
-        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);
-        }
+                device_property_read_u32(&serdev->dev, "max-speed",
+                                         &qcadev->oper_speed);
+                if (!qcadev->oper_speed)
+                        BT_DBG("UART will pick default operating speed");
 
-        err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ);
-        if (err)
-                return err;
+                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)) {
+                        dev_err(&serdev->dev, "failed to acquire enable gpio\n");
+                        return PTR_ERR(qcadev->bt_en);
+                }
 
-        err = clk_prepare_enable(qcadev->susclk);
-        if (err)
-                return err;
+                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 = hci_uart_register_device(&qcadev->serdev_hu, &qca_proto);
-        if (err)
-                clk_disable_unprepare(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);
+        }
+
+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);
 
-        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);