root/drivers/bluetooth/hci_aml.c
// SPDX-License-Identifier: (GPL-2.0-only OR MIT)
/*
 * Copyright (C) 2024 Amlogic, Inc. All rights reserved
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/property.h>
#include <linux/of.h>
#include <linux/serdev.h>
#include <linux/clk.h>
#include <linux/firmware.h>
#include <linux/gpio/consumer.h>
#include <linux/regulator/consumer.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/hci.h>

#include "hci_uart.h"

#define AML_EVT_HEAD_SIZE               4
#define AML_BDADDR_DEFAULT (&(bdaddr_t) {{ 0x00, 0xff, 0x00, 0x22, 0x2d, 0xae }})

#define AML_FIRMWARE_OPERATION_SIZE             (248)
#define AML_FIRMWARE_MAX_SIZE                   (512 * 1024)

/* TCI command */
#define AML_TCI_CMD_READ                        0xFEF0
#define AML_TCI_CMD_WRITE                       0xFEF1
#define AML_TCI_CMD_UPDATE_BAUDRATE             0xFEF2
#define AML_TCI_CMD_HARDWARE_RESET              0xFEF2
#define AML_TCI_CMD_DOWNLOAD_BT_FW              0xFEF3

/* Vendor command */
#define AML_BT_HCI_VENDOR_CMD                   0xFC1A

/* TCI operation parameter in controller chip */
#define AML_OP_UART_MODE                        0x00A30128
#define AML_OP_EVT_ENABLE                       0x00A70014
#define AML_OP_MEM_HARD_TRANS_EN                0x00A7000C
#define AML_OP_RF_CFG                           0x00F03040
#define AML_OP_RAM_POWER_CTR                    0x00F03050
#define AML_OP_HARDWARE_RST                     0x00F03058
#define AML_OP_ICCM_RAM_BASE                    0x00000000
#define AML_OP_DCCM_RAM_BASE                    0x00D00000

/* UART configuration */
#define AML_UART_XMIT_EN                        BIT(12)
#define AML_UART_RECV_EN                        BIT(13)
#define AML_UART_TIMEOUT_INT_EN                 BIT(14)
#define AML_UART_CLK_SOURCE                     40000000

/* Controller event */
#define AML_EVT_EN                              BIT(24)

/* RAM power control */
#define AML_RAM_POWER_ON                        (0)
#define AML_RAM_POWER_OFF                       (1)

/* RF configuration */
#define AML_RF_ANT_SINGLE                       BIT(28)
#define AML_RF_ANT_DOUBLE                       BIT(29)

/* Memory transaction */
#define AML_MM_CTR_HARD_TRAS_EN                 BIT(27)

/* Controller reset */
#define AML_CTR_CPU_RESET                       BIT(8)
#define AML_CTR_MAC_RESET                       BIT(9)
#define AML_CTR_PHY_RESET                       BIT(10)

enum {
        FW_ICCM,
        FW_DCCM
};

struct aml_fw_len {
        u32 iccm_len;
        u32 dccm_len;
};

struct aml_tci_rsp {
        u8 num_cmd_packet;
        u16 opcode;
        u8 status;
} __packed;

struct aml_device_data {
        int iccm_offset;
        int dccm_offset;
        bool is_coex;
};

struct aml_serdev {
        struct hci_uart serdev_hu;
        struct device *dev;
        struct gpio_desc *bt_en_gpio;
        struct regulator *bt_supply;
        struct clk *lpo_clk;
        const struct aml_device_data *aml_dev_data;
        const char *firmware_name;
};

struct aml_data {
        struct sk_buff *rx_skb;
        struct sk_buff_head txq;
};

static const struct h4_recv_pkt aml_recv_pkts[] = {
        { H4_RECV_ACL, .recv = hci_recv_frame },
        { H4_RECV_SCO, .recv = hci_recv_frame },
        { H4_RECV_EVENT, .recv = hci_recv_frame },
        { H4_RECV_ISO, .recv = hci_recv_frame },
};

/* The TCI command is a private command, which is for setting baud rate,
 * downloading firmware, initiating RAM.
 *
 * op_code |      op_len           | op_addr | parameter   |
 * --------|-----------------------|---------|-------------|
 *   2B    | 1B len(addr+param)    |    4B   |  len(param) |
 */
static int aml_send_tci_cmd(struct hci_dev *hdev, u16 op_code, u32 op_addr,
                            u32 *param, u32 param_len)
{
        struct aml_tci_rsp *rsp = NULL;
        struct sk_buff *skb = NULL;
        size_t buf_len = 0;
        u8 *buf = NULL;
        int err = 0;

        buf_len = sizeof(op_addr) + param_len;
        buf = kmalloc(buf_len, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        memcpy(buf, &op_addr, sizeof(op_addr));
        if (param && param_len > 0)
                memcpy(buf + sizeof(op_addr), param, param_len);

        skb = __hci_cmd_sync_ev(hdev, op_code, buf_len, buf,
                                HCI_EV_CMD_COMPLETE, HCI_INIT_TIMEOUT);
        if (IS_ERR(skb)) {
                err = PTR_ERR(skb);
                bt_dev_err(hdev, "Failed to send TCI cmd (error: %d)", err);
                goto exit;
        }

        rsp = skb_pull_data(skb, sizeof(struct aml_tci_rsp));
        if (!rsp)
                goto skb_free;

        if (rsp->opcode != op_code || rsp->status != 0x00) {
                bt_dev_err(hdev, "send TCI cmd (0x%04X), response (0x%04X):(%d)",
                       op_code, rsp->opcode, rsp->status);
                err = -EINVAL;
                goto skb_free;
        }

skb_free:
        kfree_skb(skb);

exit:
        kfree(buf);
        return err;
}

static int aml_update_chip_baudrate(struct hci_dev *hdev, u32 baud)
{
        u32 value;

        value = ((AML_UART_CLK_SOURCE / baud) - 1) & 0x0FFF;
        value |= AML_UART_XMIT_EN | AML_UART_RECV_EN | AML_UART_TIMEOUT_INT_EN;

        return aml_send_tci_cmd(hdev, AML_TCI_CMD_UPDATE_BAUDRATE,
                                  AML_OP_UART_MODE, &value, sizeof(value));
}

static int aml_start_chip(struct hci_dev *hdev)
{
        u32 value = 0;
        int ret;

        value = AML_MM_CTR_HARD_TRAS_EN;
        ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
                               AML_OP_MEM_HARD_TRANS_EN,
                               &value, sizeof(value));
        if (ret)
                return ret;

        /* controller hardware reset */
        value = AML_CTR_CPU_RESET | AML_CTR_MAC_RESET | AML_CTR_PHY_RESET;
        ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_HARDWARE_RESET,
                               AML_OP_HARDWARE_RST,
                               &value, sizeof(value));
        return ret;
}

static int aml_send_firmware_segment(struct hci_dev *hdev,
                                     u8 fw_type,
                                     u8 *seg,
                                     u32 seg_size,
                                     u32 offset)
{
        u32 op_addr = 0;

        if (fw_type == FW_ICCM)
                op_addr = AML_OP_ICCM_RAM_BASE  + offset;
        else if (fw_type == FW_DCCM)
                op_addr = AML_OP_DCCM_RAM_BASE + offset;

        return aml_send_tci_cmd(hdev, AML_TCI_CMD_DOWNLOAD_BT_FW,
                             op_addr, (u32 *)seg, seg_size);
}

static int aml_send_firmware(struct hci_dev *hdev, u8 fw_type,
                             u8 *fw, u32 fw_size, u32 offset)
{
        u32 seg_size = 0;
        u32 seg_off = 0;

        if (fw_size > AML_FIRMWARE_MAX_SIZE) {
                bt_dev_err(hdev,
                        "Firmware size %d kB is larger than the maximum of 512 kB. Aborting.",
                        fw_size);
                return -EINVAL;
        }
        while (fw_size > 0) {
                seg_size = (fw_size > AML_FIRMWARE_OPERATION_SIZE) ?
                           AML_FIRMWARE_OPERATION_SIZE : fw_size;
                if (aml_send_firmware_segment(hdev, fw_type, (fw + seg_off),
                                              seg_size, offset)) {
                        bt_dev_err(hdev, "Failed send firmware, type: %d, offset: 0x%x",
                               fw_type, offset);
                        return -EINVAL;
                }
                seg_off += seg_size;
                fw_size -= seg_size;
                offset += seg_size;
        }
        return 0;
}

static int aml_download_firmware(struct hci_dev *hdev, const char *fw_name)
{
        struct hci_uart *hu = hci_get_drvdata(hdev);
        struct aml_serdev *amldev = serdev_device_get_drvdata(hu->serdev);
        const struct firmware *firmware = NULL;
        struct aml_fw_len *fw_len = NULL;
        u8 *iccm_start = NULL, *dccm_start = NULL;
        u32 iccm_len, dccm_len;
        u32 value = 0;
        int ret = 0;

        /* Enable firmware download event */
        value = AML_EVT_EN;
        ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
                               AML_OP_EVT_ENABLE,
                               &value, sizeof(value));
        if (ret)
                goto exit;

        /* RAM power on */
        value = AML_RAM_POWER_ON;
        ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
                               AML_OP_RAM_POWER_CTR,
                               &value, sizeof(value));
        if (ret)
                goto exit;

        /* Check RAM power status */
        ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_READ,
                               AML_OP_RAM_POWER_CTR, NULL, 0);
        if (ret)
                goto exit;

        ret = request_firmware(&firmware, fw_name, &hdev->dev);
        if (ret < 0) {
                bt_dev_err(hdev, "Failed to load <%s>:(%d)", fw_name, ret);
                goto exit;
        }

        fw_len = (struct aml_fw_len *)firmware->data;

        /* Download ICCM */
        iccm_start = (u8 *)(firmware->data) + sizeof(struct aml_fw_len)
                        + amldev->aml_dev_data->iccm_offset;
        iccm_len = fw_len->iccm_len - amldev->aml_dev_data->iccm_offset;
        ret = aml_send_firmware(hdev, FW_ICCM, iccm_start, iccm_len,
                                amldev->aml_dev_data->iccm_offset);
        if (ret) {
                bt_dev_err(hdev, "Failed to send FW_ICCM (%d)", ret);
                goto exit;
        }

        /* Download DCCM */
        dccm_start = (u8 *)(firmware->data) + sizeof(struct aml_fw_len) + fw_len->iccm_len;
        dccm_len = fw_len->dccm_len;
        ret = aml_send_firmware(hdev, FW_DCCM, dccm_start, dccm_len,
                                amldev->aml_dev_data->dccm_offset);
        if (ret) {
                bt_dev_err(hdev, "Failed to send FW_DCCM (%d)", ret);
                goto exit;
        }

        /* Disable firmware download event */
        value = 0;
        ret = aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
                               AML_OP_EVT_ENABLE,
                               &value, sizeof(value));
        if (ret)
                goto exit;

exit:
        release_firmware(firmware);
        return ret;
}

static int aml_send_reset(struct hci_dev *hdev)
{
        struct sk_buff *skb;
        int err;

        skb = __hci_cmd_sync_ev(hdev, HCI_OP_RESET, 0, NULL,
                                HCI_EV_CMD_COMPLETE, HCI_INIT_TIMEOUT);
        if (IS_ERR(skb)) {
                err = PTR_ERR(skb);
                bt_dev_err(hdev, "Failed to send hci reset cmd (%d)", err);
                return err;
        }

        kfree_skb(skb);
        return 0;
}

static int aml_dump_fw_version(struct hci_dev *hdev)
{
        struct aml_tci_rsp *rsp = NULL;
        struct sk_buff *skb;
        u8 value[6] = {0};
        u8 *fw_ver = NULL;
        int err = 0;

        skb = __hci_cmd_sync_ev(hdev, AML_BT_HCI_VENDOR_CMD, sizeof(value), value,
                                HCI_EV_CMD_COMPLETE, HCI_INIT_TIMEOUT);
        if (IS_ERR(skb)) {
                err = PTR_ERR(skb);
                bt_dev_err(hdev, "Failed to get fw version (error: %d)", err);
                return err;
        }

        rsp = skb_pull_data(skb, sizeof(struct aml_tci_rsp));
        if (!rsp)
                goto exit;

        if (rsp->opcode != AML_BT_HCI_VENDOR_CMD || rsp->status != 0x00) {
                bt_dev_err(hdev, "dump version, error response (0x%04X):(%d)",
                       rsp->opcode, rsp->status);
                err = -EINVAL;
                goto exit;
        }

        fw_ver = (u8 *)rsp + AML_EVT_HEAD_SIZE;
        bt_dev_info(hdev, "fw_version: date = %02x.%02x, number = 0x%02x%02x",
                *(fw_ver + 1), *fw_ver, *(fw_ver + 3), *(fw_ver + 2));

exit:
        kfree_skb(skb);
        return err;
}

static int aml_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
{
        struct aml_tci_rsp *rsp = NULL;
        struct sk_buff *skb;
        int err = 0;

        bt_dev_info(hdev, "set bdaddr (%pM)", bdaddr);
        skb = __hci_cmd_sync_ev(hdev, AML_BT_HCI_VENDOR_CMD,
                                sizeof(bdaddr_t), bdaddr,
                                HCI_EV_CMD_COMPLETE, HCI_INIT_TIMEOUT);
        if (IS_ERR(skb)) {
                err = PTR_ERR(skb);
                bt_dev_err(hdev, "Failed to set bdaddr (error: %d)", err);
                return err;
        }

        rsp = skb_pull_data(skb, sizeof(struct aml_tci_rsp));
        if (!rsp)
                goto exit;

        if (rsp->opcode != AML_BT_HCI_VENDOR_CMD || rsp->status != 0x00) {
                bt_dev_err(hdev, "error response (0x%x):(%d)", rsp->opcode, rsp->status);
                err = -EINVAL;
                goto exit;
        }

exit:
        kfree_skb(skb);
        return err;
}

static int aml_check_bdaddr(struct hci_dev *hdev)
{
        struct hci_rp_read_bd_addr *paddr;
        struct sk_buff *skb;
        int err;

        if (bacmp(&hdev->public_addr, BDADDR_ANY))
                return 0;

        skb = __hci_cmd_sync(hdev, HCI_OP_READ_BD_ADDR, 0, NULL,
                             HCI_INIT_TIMEOUT);
        if (IS_ERR(skb)) {
                err = PTR_ERR(skb);
                bt_dev_err(hdev, "Failed to read bdaddr (error: %d)", err);
                return err;
        }

        paddr = skb_pull_data(skb, sizeof(struct hci_rp_read_bd_addr));
        if (!paddr)
                goto exit;

        if (!bacmp(&paddr->bdaddr, AML_BDADDR_DEFAULT)) {
                bt_dev_info(hdev, "amlbt using default bdaddr (%pM)", &paddr->bdaddr);
                hci_set_quirk(hdev, HCI_QUIRK_INVALID_BDADDR);
        }

exit:
        kfree_skb(skb);
        return 0;
}

static int aml_config_rf(struct hci_dev *hdev, bool is_coex)
{
        u32 value = AML_RF_ANT_DOUBLE;

        /* Use a single antenna when co-existing with wifi */
        if (is_coex)
                value = AML_RF_ANT_SINGLE;

        return aml_send_tci_cmd(hdev, AML_TCI_CMD_WRITE,
                                AML_OP_RF_CFG,
                                &value, sizeof(value));
}

static int aml_parse_dt(struct aml_serdev *amldev)
{
        struct device *pdev = amldev->dev;

        amldev->bt_en_gpio = devm_gpiod_get(pdev, "enable",
                                        GPIOD_OUT_LOW);
        if (IS_ERR(amldev->bt_en_gpio)) {
                dev_err(pdev, "Failed to acquire enable gpios");
                return PTR_ERR(amldev->bt_en_gpio);
        }

        if (device_property_read_string(pdev, "firmware-name",
                                        &amldev->firmware_name)) {
                dev_err(pdev, "Failed to acquire firmware path");
                return -ENODEV;
        }

        amldev->bt_supply = devm_regulator_get(pdev, "vddio");
        if (IS_ERR(amldev->bt_supply)) {
                dev_err(pdev, "Failed to acquire regulator");
                return PTR_ERR(amldev->bt_supply);
        }

        amldev->lpo_clk = devm_clk_get(pdev, NULL);
        if (IS_ERR(amldev->lpo_clk)) {
                dev_err(pdev, "Failed to acquire clock source");
                return PTR_ERR(amldev->lpo_clk);
        }

        return 0;
}

static int aml_power_on(struct aml_serdev *amldev)
{
        int err;

        err = regulator_enable(amldev->bt_supply);
        if (err) {
                dev_err(amldev->dev, "Failed to enable regulator: (%d)", err);
                return err;
        }

        err = clk_prepare_enable(amldev->lpo_clk);
        if (err) {
                dev_err(amldev->dev, "Failed to enable lpo clock: (%d)", err);
                return err;
        }

        gpiod_set_value_cansleep(amldev->bt_en_gpio, 1);

        /* Wait 20ms for bluetooth controller power on */
        msleep(20);
        return 0;
}

static int aml_power_off(struct aml_serdev *amldev)
{
        gpiod_set_value_cansleep(amldev->bt_en_gpio, 0);

        clk_disable_unprepare(amldev->lpo_clk);

        regulator_disable(amldev->bt_supply);

        return 0;
}

static int aml_set_baudrate(struct hci_uart *hu, unsigned int speed)
{
        /* update controller baudrate */
        if (aml_update_chip_baudrate(hu->hdev, speed) != 0) {
                bt_dev_err(hu->hdev, "Failed to update baud rate");
                return -EINVAL;
        }

        /* update local baudrate */
        serdev_device_set_baudrate(hu->serdev, speed);

        return 0;
}

/* Initialize protocol */
static int aml_open(struct hci_uart *hu)
{
        struct aml_serdev *amldev = serdev_device_get_drvdata(hu->serdev);
        struct aml_data *aml_data;
        int err;

        err = aml_parse_dt(amldev);
        if (err)
                return err;

        if (!hci_uart_has_flow_control(hu)) {
                bt_dev_err(hu->hdev, "no flow control");
                return -EOPNOTSUPP;
        }

        aml_data = kzalloc_obj(*aml_data);
        if (!aml_data)
                return -ENOMEM;

        skb_queue_head_init(&aml_data->txq);

        hu->priv = aml_data;

        return 0;
}

static int aml_close(struct hci_uart *hu)
{
        struct aml_serdev *amldev = serdev_device_get_drvdata(hu->serdev);
        struct aml_data *aml_data = hu->priv;

        skb_queue_purge(&aml_data->txq);
        kfree_skb(aml_data->rx_skb);
        kfree(aml_data);

        hu->priv = NULL;

        return aml_power_off(amldev);
}

static int aml_flush(struct hci_uart *hu)
{
        struct aml_data *aml_data = hu->priv;

        skb_queue_purge(&aml_data->txq);

        return 0;
}

static int aml_setup(struct hci_uart *hu)
{
        struct aml_serdev *amldev = serdev_device_get_drvdata(hu->serdev);
        struct hci_dev *hdev = amldev->serdev_hu.hdev;
        int err;

        /* Setup bdaddr */
        hdev->set_bdaddr = aml_set_bdaddr;

        err = aml_power_on(amldev);
        if (err)
                return err;

        err = aml_set_baudrate(hu, amldev->serdev_hu.proto->oper_speed);
        if (err)
                return err;

        err = aml_download_firmware(hdev, amldev->firmware_name);
        if (err)
                return err;

        err = aml_config_rf(hdev, amldev->aml_dev_data->is_coex);
        if (err)
                return err;

        err = aml_start_chip(hdev);
        if (err)
                return err;

        /* Wait 60ms for controller startup */
        msleep(60);

        err = aml_dump_fw_version(hdev);
        if (err)
                return err;

        err = aml_send_reset(hdev);
        if (err)
                return err;

        err = aml_check_bdaddr(hdev);
        if (err)
                return err;

        return 0;
}

static int aml_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
        struct aml_data *aml_data = hu->priv;

        skb_queue_tail(&aml_data->txq, skb);

        return 0;
}

static struct sk_buff *aml_dequeue(struct hci_uart *hu)
{
        struct aml_data *aml_data = hu->priv;
        struct sk_buff *skb;

        skb = skb_dequeue(&aml_data->txq);

        /* Prepend skb with frame type */
        if (skb)
                memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);

        return skb;
}

static int aml_recv(struct hci_uart *hu, const void *data, int count)
{
        struct aml_data *aml_data = hu->priv;
        int err;

        aml_data->rx_skb = h4_recv_buf(hu, aml_data->rx_skb, data, count,
                                       aml_recv_pkts,
                                       ARRAY_SIZE(aml_recv_pkts));
        if (IS_ERR(aml_data->rx_skb)) {
                err = PTR_ERR(aml_data->rx_skb);
                bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
                aml_data->rx_skb = NULL;
                return err;
        }

        return count;
}

static const struct hci_uart_proto aml_hci_proto = {
        .id             = HCI_UART_AML,
        .name           = "AML",
        .init_speed     = 115200,
        .oper_speed     = 4000000,
        .open           = aml_open,
        .close          = aml_close,
        .setup          = aml_setup,
        .flush          = aml_flush,
        .recv           = aml_recv,
        .enqueue        = aml_enqueue,
        .dequeue        = aml_dequeue,
};

static int aml_serdev_probe(struct serdev_device *serdev)
{
        struct aml_serdev *amldev;
        int err;

        amldev = devm_kzalloc(&serdev->dev, sizeof(*amldev), GFP_KERNEL);
        if (!amldev)
                return -ENOMEM;

        amldev->serdev_hu.serdev = serdev;
        amldev->dev = &serdev->dev;
        serdev_device_set_drvdata(serdev, amldev);

        err = hci_uart_register_device(&amldev->serdev_hu, &aml_hci_proto);
        if (err)
                return dev_err_probe(amldev->dev, err,
                              "Failed to register hci uart device");

        amldev->aml_dev_data = device_get_match_data(&serdev->dev);

        return 0;
}

static void aml_serdev_remove(struct serdev_device *serdev)
{
        struct aml_serdev *amldev = serdev_device_get_drvdata(serdev);

        hci_uart_unregister_device(&amldev->serdev_hu);
}

static void aml_serdev_shutdown(struct serdev_device *serdev)
{
        struct aml_serdev *amldev = serdev_device_get_drvdata(serdev);

        aml_power_off(amldev);
}

static const struct aml_device_data data_w155s2 = {
        .iccm_offset = 256 * 1024,
};

static const struct aml_device_data data_w265s2 = {
        .iccm_offset = 384 * 1024,
};

static const struct of_device_id aml_bluetooth_of_match[] = {
        { .compatible = "amlogic,w155s2-bt", .data = &data_w155s2 },
        { .compatible = "amlogic,w265s2-bt", .data = &data_w265s2 },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, aml_bluetooth_of_match);

static struct serdev_device_driver aml_serdev_driver = {
        .probe = aml_serdev_probe,
        .remove = aml_serdev_remove,
        .shutdown = aml_serdev_shutdown,
        .driver = {
                .name = "hci_uart_aml",
                .of_match_table = aml_bluetooth_of_match,
        },
};

int __init aml_init(void)
{
        serdev_device_driver_register(&aml_serdev_driver);

        return hci_uart_register_proto(&aml_hci_proto);
}

int __exit aml_deinit(void)
{
        serdev_device_driver_unregister(&aml_serdev_driver);

        return hci_uart_unregister_proto(&aml_hci_proto);
}