Add support to set voltage/current of various regulators to power up/down Bluetooth chip wcn3990. Signed-off-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx> --- changes in v10: * added support to read regulator currents from dts. * added support to try to connect with chip if it fails to respond to initial commands * updated review comments. changes in v9: * moved flow control to vendor and set_baudarte functions. * removed parent regs. changes in v8: * closing qca buffer, if qca_power_setup fails * chnaged ibs start timer function call location. * updated review comments. changes in v7: * addressed review comments. changes in v6: * Hooked up qca_power to qca_serdev. * renamed all the naming inconsistency functions with qca_* * leveraged common code of ROME for wcn3990. * created wrapper functions for re-usable blocks. * updated function of _*regulator_enable and _*regualtor_disable. * removed redundant comments and functions. * addressed review comments. Changes in v5: * updated regulator vddpa min_uV to 1304000. * addressed review comments. Changes in v4: * Segregated the changes of btqca from hci_qca * rebased all changes on top of bluetooth-next. * addressed review comments. --- drivers/bluetooth/btqca.h | 4 + drivers/bluetooth/hci_qca.c | 481 ++++++++++++++++++++++++++++++++---- 2 files changed, 439 insertions(+), 46 deletions(-) diff --git a/drivers/bluetooth/btqca.h b/drivers/bluetooth/btqca.h index a9c2779f3e07..9e2bbcf5c002 100644 --- a/drivers/bluetooth/btqca.h +++ b/drivers/bluetooth/btqca.h @@ -37,6 +37,10 @@ #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 +#define QCA_WCN3990_FORCE_BOOT_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 a6e7d38ef931..7ed35eb3f480 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; + 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 int 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_vendor_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 vendor 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, as WCN3990 supports RF COEX frequency 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. This algorithm will help to + * save power. Disabling hardware flow control is mandatory while + * sending vendor pulses to SoC. + */ + bt_dev_dbg(hdev, "sending vendor 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; } @@ -985,15 +1098,78 @@ 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, u32 *soc_ver) +{ + struct hci_dev *hdev = hu->hdev; + int i, ret = 1; + + /* WCN3990 is a discrete Bluetooth chip connected to APPS processor. + * sometimes we will face communication synchronization issues, + * like reading version command timeouts. In which HCI_SETUP fails, + * to overcome these issues, we try to communicate by performing an + * COLD power OFF and ON. + */ + for (i = 1; i <= 10 && ret; i++) { + /* This helper will turn ON chip if it is powered off. + * if the chip is already powered ON, function call will + * return zero. + */ + ret = qca_power_setup(hu, true); + if (ret) + goto regs_off; + + /* Forcefully enable wcn3990 to enter in to boot mode. */ + host_set_baudrate(hu, 2400); + ret = qca_send_vendor_pulse(hdev, QCA_WCN3990_FORCE_BOOT_PULSE); + if (ret) + goto regs_off; + + qca_set_speed(hu, QCA_INIT_SPEED); + ret = qca_send_vendor_pulse(hdev, QCA_WCN3990_POWERON_PULSE); + if (ret) + goto regs_off; + + /* 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"); + break; + } + + hci_uart_set_flow_control(hu, false); + ret = qca_read_soc_version(hdev, soc_ver); + if (ret < 0 || soc_ver == 0) + bt_dev_err(hdev, "Failed to get version:%d", ret); + + if (!ret) + break; + +regs_off: + bt_dev_err(hdev, "retrying to establish communication: %d", i); + qca_power_shutdown(hdev); + } + + return ret; +} + 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 +1178,15 @@ 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, &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 +1198,16 @@ 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 +1243,174 @@ 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, 1800000, 15000 }, + { "vddxo", 1800000, 1800000, 80000 }, + { "vddrf", 1304000, 1304000, 300000 }, + { "vddch0", 3000000, 3312000, 450000 }, + }, + .num_vregs = 4, +}; + +static int qca_power_shutdown(struct hci_dev *hdev) +{ + struct hci_uart *hu = hci_get_drvdata(hdev); + + host_set_baudrate(hu, 2400); + qca_send_vendor_pulse(hdev, QCA_WCN3990_POWEROFF_PULSE); + return 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 void qca_regulator_get_current(struct device *dev, + struct qca_vreg *vregs) +{ + char prop_name[32]; /* 32 is max size of property name */ + + /* We have different platforms where the load value is controlled + * via PMIC controllers. In such cases load required to power ON + * Bluetooth chips are defined in the PMIC. We have option to set + * operation mode like high or low power modes. + * We do have some platforms where driver need to enable the load for + * WCN3990. Based on the current property value defined for the + * regulators, driver will decide the regulator output load. + * If the current property for the regulator is defined in the dts + * we will read from dts tree, else from the default load values. + */ + snprintf(prop_name, 32, "%s-current", vregs->name); + BT_DBG("Looking up %s from device tree\n", prop_name); + + if (device_property_read_bool(dev, prop_name)) + device_property_read_u32(dev, prop_name, &vregs->load_uA); + + BT_DBG("current %duA selected for regulator %s", vregs->load_uA, + vregs->name); +} + +static int qca_init_regulators(struct qca_power *qca, + const struct qca_vreg_data *data) +{ + int i, num_vregs; + int load_uA; + + num_vregs = data->num_vregs; + qca->vreg_bulk = devm_kzalloc(qca->dev, num_vregs * + sizeof(struct regulator_bulk_data), + GFP_KERNEL); + if (!qca->vreg_bulk) + return -ENOMEM; + + qca->vreg_data = devm_kzalloc(qca->dev, sizeof(struct qca_vreg_data), + GFP_KERNEL); + if (!qca->vreg_data) + return -ENOMEM; + + qca->vreg_data->num_vregs = data->num_vregs; + qca->vreg_data->soc_type = data->soc_type; + + qca->vreg_data->vregs = devm_kzalloc(qca->dev, num_vregs * + sizeof(struct qca_vreg_data), + GFP_KERNEL); + + if (!qca->vreg_data->vregs) + return -ENOMEM; + + for (i = 0; i < num_vregs; i++) { + /* copy regulator name, min voltage, max voltage */ + qca->vreg_data->vregs[i].name = data->vregs[i].name; + qca->vreg_data->vregs[i].min_uV = data->vregs[i].min_uV; + qca->vreg_data->vregs[i].max_uV = data->vregs[i].max_uV; + load_uA = data->vregs[i].load_uA; + qca->vreg_data->vregs[i].load_uA = load_uA; + qca_regulator_get_current(qca->dev, &qca->vreg_data->vregs[i]); + + qca->vreg_bulk[i].supply = qca->vreg_data->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 +1418,87 @@ 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; + err = qca_init_regulators(qcadev->bt_power, data); + 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); - } + /* Read max speed supported by wcn3990 from dts + * tree. if max-speed property is not enabled in + * dts, QCA driver will use default operating speed + * from proto structure. + */ + device_property_read_u32(&serdev->dev, "max-speed", + &qcadev->oper_speed); + if (!qcadev->oper_speed) + BT_INFO("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)) { + dev_err(&serdev->dev, "failed to acquire enable gpio\n"); + return PTR_ERR(qcadev->bt_en); + } - err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ); - 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 = clk_prepare_enable(qcadev->susclk); - if (err) - return err; + 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) - clk_disable_unprepare(qcadev->susclk); + 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); -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html