Re: [PATCH v1 3/3] Bluetooth: NXP: Add protocol support for NXP Bluetooth chipsets

Ilpo Järvinen
2023-01-25T11:22:56Z

On Tue, 24 Jan 2023, Neeraj Sanjay Kale wrote:

> This adds a driver based on serdev driver for the NXP BT serial
> protocol based on running H:4, which can enable the built-in
> Bluetooth device inside a generic NXP BT chip.
>
> This driver has Power Save feature that will put the chip into
> sleep state whenever there is no activity for 2000ms, and will
> be woken up when any activity is to be initiated.
>
> This driver enables the power save feature by default by sending
> the vendor specific commands to the chip during setup.
>
> During setup, the driver is capable of reading the bootloader
> signature unique to every chip, and downloading corresponding
> FW file defined in a user-space config file. The firmware file
> name can be defined in DTS file as well, in which case the
> user-space config file will be ignored.
>
> Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
> ---
> MAINTAINERS | 7 +
> drivers/bluetooth/Kconfig | 11 +
> drivers/bluetooth/Makefile | 1 +
> drivers/bluetooth/btnxp.c | 1337 ++++++++++++++++++++++++++++++++++++
> drivers/bluetooth/btnxp.h | 230 +++++++
> 5 files changed, 1586 insertions(+)
> create mode 100644 drivers/bluetooth/btnxp.c
> create mode 100644 drivers/bluetooth/btnxp.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 32dd41574930..20bb9e6b44b5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -22835,6 +22835,13 @@ L: linux-mm@kvack.org
> S: Maintained
> F: mm/zswap.c
>
> +NXP BLUETOOTH WIRELESS DRIVERS
> +M: Amitkumar Karwar <amitkumar.karwar@nxp.com>
> +M: Neeraj Kale <neeraj.sanjaykale@nxp.com>
> +S: Maintained
> +F: Documentation/devicetree/bindings/net/bluetooth/nxp-bluetooth.yaml
> +F: drivers/bluetooth/btnxp*
> +
> THE REST
> M: Linus Torvalds <torvalds@linux-foundation.org>
> L: linux-kernel@vger.kernel.org
> diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
> index 5a1a7bec3c42..773b40d34b7b 100644
> --- a/drivers/bluetooth/Kconfig
> +++ b/drivers/bluetooth/Kconfig
> @@ -465,4 +465,15 @@ config BT_VIRTIO
> Say Y here to compile support for HCI over Virtio into the
> kernel or say M to compile as a module.
>
> +config BT_NXPUART
> + tristate "NXP protocol support"
> + depends on SERIAL_DEV_BUS
> + help
> + NXP is serial driver required for NXP Bluetooth
> + devices with UART interface.
> +
> + Say Y here to compile support for NXP Bluetooth UART device into
> + the kernel, or say M here to compile as a module.
> +
> +
> endmenu
> diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
> index e0b261f24fc9..6c0e7fbe2297 100644
> --- a/drivers/bluetooth/Makefile
> +++ b/drivers/bluetooth/Makefile
> @@ -29,6 +29,7 @@ obj-$(CONFIG_BT_QCA) += btqca.o
> obj-$(CONFIG_BT_MTK) += btmtk.o
>
> obj-$(CONFIG_BT_VIRTIO) += virtio_bt.o
> +obj-$(CONFIG_BT_NXPUART) += btnxp.o
>
> obj-$(CONFIG_BT_HCIUART_NOKIA) += hci_nokia.o
>
> diff --git a/drivers/bluetooth/btnxp.c b/drivers/bluetooth/btnxp.c
> new file mode 100644
> index 000000000000..0066f778593a
> --- /dev/null
> +++ b/drivers/bluetooth/btnxp.c
> @@ -0,0 +1,1337 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + *
> + * NXP Bluetooth driver
> + * Copyright 2018-2023 NXP
> + *
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +
> +#include <linux/serdev.h>
> +#include <linux/of.h>
> +#include <linux/skbuff.h>
> +#include <asm/unaligned.h>
> +#include <linux/firmware.h>
> +#include <linux/string.h>
> +#include <linux/crc8.h>
> +
> +#include <net/bluetooth/bluetooth.h>
> +#include <net/bluetooth/hci_core.h>
> +
> +#include "btnxp.h"
> +#include "h4_recv.h"
> +
> +#define BTNXPUART_TX_STATE_ACTIVE 1
> +#define BTNXPUART_TX_STATE_WAKEUP 2
> +#define BTNXPUART_FW_DOWNLOADING 3
> +
> +static const struct chip_id_map_table chip_id_name_table[] = {
> + {0xffff, "legacy_chip"}, /* for legacy bootloader chipsets w8987 and w8997 */
> + {0x7201, "iw416"},
> + {0x7601, "iw612"},
> + {0x5c03, "w9098"},
> +};
> +
> +static u8 crc8_table[CRC8_TABLE_SIZE];
> +static unsigned long crc32_table[256];
> +static struct fw_params fw_mod_params[MAX_NO_OF_CHIPS_SUPPORT];
> +
> +/* NXP Power Save Feature */
> +int wakeupmode = WAKEUP_METHOD_BREAK;
> +int ps_mode = PS_MODE_ENABLE;
> +
> +static void ps_start_timer(struct btnxpuart_dev *nxpdev)
> +{
> + struct ps_data *psdata = nxpdev->psdata;
> +
> + if (!psdata)
> + return;
> +
> + if (psdata->cur_psmode == PS_MODE_ENABLE) {
> + psdata->timer_on = 1;
> + mod_timer(&psdata->ps_timer, jiffies + (psdata->interval * HZ) / 1000);
> + }
> +}
> +
> +static void ps_cancel_timer(struct btnxpuart_dev *nxpdev)
> +{
> + struct ps_data *psdata = nxpdev->psdata;
> +
> + if (!psdata)
> + return;
> +
> + flush_scheduled_work();
> + if (psdata->timer_on)
> + del_timer(&psdata->ps_timer);
> + kfree(psdata);
> +}
> +
> +static void ps_control(struct hci_dev *hdev, u8 ps_state)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + struct ps_data *psdata = nxpdev->psdata;
> +
> + if (psdata->ps_state == ps_state)
> + return;
> +
> + switch (psdata->cur_wakeupmode) {
> + case WAKEUP_METHOD_DTR:
> + if (ps_state == PS_STATE_AWAKE)
> + serdev_device_set_tiocm(nxpdev->serdev, TIOCM_DTR, 0); /* DTR ON */
> + else
> + serdev_device_set_tiocm(nxpdev->serdev, 0, TIOCM_DTR); /* DTR OFF */
> + break;
> + case WAKEUP_METHOD_BREAK:
> + default:
> + BT_INFO("Set UART break: %s", ps_state == PS_STATE_AWAKE ? "off" : "on");
> + if (ps_state == PS_STATE_AWAKE)
> + serdev_device_break_ctl(nxpdev->serdev, 0); /* break OFF */
> + else
> + serdev_device_break_ctl(nxpdev->serdev, -1); /* break ON */
> + break;
> + }
> + psdata->ps_state = ps_state;
> +
> + if (ps_state == PS_STATE_AWAKE)
> + btnxpuart_tx_wakeup(nxpdev);
> +}
> +
> +static void ps_work_func(struct work_struct *work)
> +{
> + struct ps_data *data = container_of(work, struct ps_data, work);
> +
> + if (data->ps_cmd == PS_CMD_ENTER_PS && data->cur_psmode == PS_MODE_ENABLE)
> + ps_control(data->hdev, PS_STATE_SLEEP);
> + else if (data->ps_cmd == PS_CMD_EXIT_PS)
> + ps_control(data->hdev, PS_STATE_AWAKE);
> +}
> +
> +static void ps_timeout_func(struct timer_list *t)
> +{
> + struct ps_data *data = from_timer(data, t, ps_timer);
> + struct hci_dev *hdev = data->hdev;
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> +
> + data->timer_on = 0;
> + if (test_bit(BTNXPUART_TX_STATE_ACTIVE, &nxpdev->tx_state)) {
> + ps_start_timer(nxpdev);
> + } else {
> + data->ps_cmd = PS_CMD_ENTER_PS;
> + schedule_work(&data->work);
> + }
> +}
> +
> +static int ps_init_work(struct hci_dev *hdev)
> +{
> + struct ps_data *psdata = kzalloc(sizeof(*psdata), GFP_KERNEL);
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> +
> + if (!psdata) {
> + BT_ERR("Can't allocate control structure for Power Save feature");
> + return -ENOMEM;
> + }
> + nxpdev->psdata = psdata;
> +
> + memset(psdata, 0, sizeof(*psdata));

Why memset to zero kzalloc'ed mem?

> + psdata->interval = PS_DEFAULT_TIMEOUT_PERIOD;
> + psdata->ps_state = PS_STATE_AWAKE;
> + psdata->ps_mode = ps_mode;
> + psdata->hdev = hdev;
> +
> + switch (wakeupmode) {
> + case WAKEUP_METHOD_DTR:
> + psdata->wakeupmode = WAKEUP_METHOD_DTR;
> + break;
> + case WAKEUP_METHOD_BREAK:
> + default:
> + psdata->wakeupmode = WAKEUP_METHOD_BREAK;
> + break;
> + }
> +
> + psdata->cur_psmode = PS_MODE_DISABLE;
> + psdata->cur_wakeupmode = WAKEUP_METHOD_INVALID;
> + INIT_WORK(&psdata->work, ps_work_func);
> +
> + return 0;
> +}
> +
> +static void ps_init_timer(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + struct ps_data *psdata = nxpdev->psdata;
> +
> + psdata->timer_on = 0;
> + timer_setup(&psdata->ps_timer, ps_timeout_func, 0);
> +}
> +
> +static int ps_wakeup(struct btnxpuart_dev *nxpdev)
> +{
> + struct ps_data *psdata = nxpdev->psdata;
> + int ret = 1;
> +
> + if (psdata->ps_state == PS_STATE_AWAKE)
> + ret = 0;
> + psdata->ps_cmd = PS_CMD_EXIT_PS;
> + schedule_work(&psdata->work);
> +
> + return ret;
> +}
> +
> +static int send_ps_cmd(struct hci_dev *hdev, void *data)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + struct ps_data *psdata = nxpdev->psdata;
> + u8 pcmd;
> + struct sk_buff *skb;
> + u8 *status;
> +
> + if (psdata->ps_mode == PS_MODE_ENABLE)
> + pcmd = BT_PS_ENABLE;
> + else
> + pcmd = BT_PS_DISABLE;
> +
> + psdata->driver_sent_cmd = true; /* set flag to prevent re-sending command in nxp_enqueue */
> + skb = __hci_cmd_sync(hdev, HCI_NXP_AUTO_SLEEP_MODE, 1, &pcmd, HCI_CMD_TIMEOUT);
> + psdata->driver_sent_cmd = false;

A helper for these 3 lines?

> + if (IS_ERR(skb)) {
> + bt_dev_err(hdev, "Setting Power Save mode failed (%ld)",
> + PTR_ERR(skb));
> + return PTR_ERR(skb);
> + }
> +
> + status = skb_pull_data(skb, 1);
> +
> + if (status) {
> + if (!*status)
> + psdata->cur_psmode = psdata->ps_mode;
> + else
> + psdata->ps_mode = psdata->cur_psmode;
> + if (psdata->cur_psmode == PS_MODE_ENABLE)
> + ps_start_timer(nxpdev);
> + else
> + ps_wakeup(nxpdev);
> + BT_INFO("Power Save mode response: status=%d, ps_mode=%d",
> + *status, psdata->cur_psmode);
> + }
> + return 0;
> +}
> +
> +static int send_wakeup_method_cmd(struct hci_dev *hdev, void *data)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + struct ps_data *psdata = nxpdev->psdata;
> + u8 pcmd[4];
> + struct sk_buff *skb;
> + u8 *status;
> +
> + pcmd[0] = BT_HOST_WAKEUP_METHOD_NONE;
> + pcmd[1] = BT_HOST_WAKEUP_DEFAULT_GPIO;
> + switch (psdata->wakeupmode) {
> + case WAKEUP_METHOD_DTR:
> + pcmd[2] = BT_CTRL_WAKEUP_METHOD_DSR;
> + break;
> + case WAKEUP_METHOD_BREAK:
> + default:
> + pcmd[2] = BT_CTRL_WAKEUP_METHOD_BREAK;
> + break;
> + }
> + pcmd[3] = 0xFF;
> +
> + psdata->driver_sent_cmd = true; /* set flag to prevent re-sending command in nxp_enqueue */
> + skb = __hci_cmd_sync(hdev, HCI_NXP_WAKEUP_METHOD, 4, pcmd, HCI_CMD_TIMEOUT);
> + psdata->driver_sent_cmd = false;
> +
> + if (IS_ERR(skb)) {
> + bt_dev_err(hdev, "Setting wake-up method failed (%ld)",
> + PTR_ERR(skb));
> + return PTR_ERR(skb);
> + }
> +
> + status = skb_pull_data(skb, 1);
> + if (status) {
> + if (*status == 0)
> + psdata->cur_wakeupmode = psdata->wakeupmode;
> + else
> + psdata->wakeupmode = psdata->cur_wakeupmode;
> + BT_INFO("Set Wakeup Method response: status=%d, wakeupmode=%d",
> + *status, psdata->cur_wakeupmode);
> + }

Do you need to free the skb?

> +
> + return 0;
> +}
> +
> +static int ps_init(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + struct ps_data *psdata = nxpdev->psdata;
> +
> + serdev_device_set_tiocm(nxpdev->serdev, TIOCM_RTS, 0); /* RTS ON */
> +
> + switch (psdata->wakeupmode) {
> + case WAKEUP_METHOD_DTR:
> + serdev_device_set_tiocm(nxpdev->serdev, 0, TIOCM_DTR); /* DTR OFF */
> + serdev_device_set_tiocm(nxpdev->serdev, TIOCM_DTR, 0); /* DTR ON */
> + break;
> + case WAKEUP_METHOD_BREAK:
> + default:
> + serdev_device_break_ctl(nxpdev->serdev, -1); /* break ON */
> + serdev_device_break_ctl(nxpdev->serdev, 0); /* break OFF */

I'm not convinced these 5 comments really add any useful info.

> + break;
> + }
> + if (!test_bit(HCI_RUNNING, &hdev->flags)) {
> + BT_ERR("HCI_RUNNING is not set");
> + return -EBUSY;
> + }
> + if (psdata->cur_wakeupmode != psdata->wakeupmode)
> + hci_cmd_sync_queue(hdev, send_wakeup_method_cmd, NULL, NULL);
> + if (psdata->cur_psmode != psdata->ps_mode)
> + hci_cmd_sync_queue(hdev, send_ps_cmd, NULL, NULL);
> +
> + return 0;
> +}
> +
> +/* NXP Firmware Download Feature */
> +static u16 nxp_get_chip_id_from_name(u8 *name_str)
> +{
> + int map_table_size = sizeof(chip_id_name_table) / sizeof(struct chip_id_map_table);
> + int i;
> +
> + for (i = 0; i < map_table_size; i++) {

Isn't this just ARRAY_SIZE(chip_id_name_table)? use it directly here,
no need for the extra variable?

> + if (!strcmp(chip_id_name_table[i].chip_name, name_str))
> + return chip_id_name_table[i].chip_id;
> + }
> +
> + return 0; /* invalid name_str */

Put such comment preferrably to function's comment if you want to note
things like this or create a properly named define for it.

> +}
> +
> +static int nxp_parse_conf_file(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + const char *sptr;
> + char *dptr, *label, *value;
> + char line[100];
> + int i = 0;
> + int param_index = 0;
> + int line_num = 1;
> + int ret = 0;
> + bool skipline = false;
> + bool valid_param = false;

Reverse xmas-tree order would help while reading these.

> +
> + memset(fw_mod_params, 0, sizeof(fw_mod_params));
> + sptr = nxpdev->fw_config->data;
> + dptr = line;
> + for (i = 0; i < nxpdev->fw_config->size; i++) {
> + /* if current line is a comment, ignore */
> + if (sptr[i] == '#') {
> + skipline = true;
> + continue;
> + }
> + if (sptr[i] != '\n' && skipline)
> + continue;
> + /* ignore space <CR> and comma*/

Missing space.

> + if (sptr[i] == ' ' || sptr[i] == '\r' || sptr[i] == ',')
> + continue;
> + /* select next fw_mod_params index */
> + if (sptr[i] == '}') {
> + if (!valid_param) {
> + BT_ERR("Unexpected '}' on line %d", line_num);
> + ret = -1;
> + goto err;
> + }
> + param_index++;
> + valid_param = false;
> + continue;
> + }
> + if (sptr[i] == '\n') {
> + line_num++;
> + if (skipline) {
> + skipline = false;
> + continue;
> + }
> + *dptr = '\0';
> + /* ignore empty lines */
> + if (strlen(line) == 0)
> + continue;
> + dptr = line;
> + label = strsep(&dptr, "=");
> + value = strsep(&dptr, "=");
> + if (label && value) {
> + if (!strcmp(value, "{")) {
> + valid_param = true;
> + strncpy(fw_mod_params[param_index].chip_name,
> + label, MAX_CHIP_NAME_LEN);
> + fw_mod_params[param_index].chip_id =
> + nxp_get_chip_id_from_name(label);
> + if (fw_mod_params[param_index].chip_id == 0) {
> + BT_ERR("Invalid label %s in %s", label,
> + BT_FW_CONF_FILE);
> + ret = -1;
> + goto err;
> + }
> + } else {
> + if (!valid_param) {
> + BT_ERR("Expecting a '{' on line %d", line_num - 1);
> + ret = -1;
> + goto err;
> + }
> + if (!strcmp(label, FW_NAME_TAG)) {
> + strncpy(fw_mod_params[param_index].fw_name,
> + value, MAX_FW_FILE_NAME_LEN);
> + } else if (!strcmp(label, OPER_SPEED_TAG)) {
> + ret = kstrtouint(value, 10,
> + &fw_mod_params[param_index].oper_speed);
> + } else if (!strcmp(label, FW_DL_PRI_BAUDRATE_TAG)) {
> + ret = kstrtouint(value, 10,
> + &fw_mod_params[param_index].fw_dnld_pri_baudrate);
> + } else if (!strcmp(label, FW_DL_SEC_BAUDRATE_TAG)) {
> + ret = kstrtouint(value, 10,
> + &fw_mod_params[param_index].fw_dnld_sec_baudrate);
> + } else if (!strcmp(label, FW_INIT_BAUDRATE)) {
> + ret = kstrtouint(value, 10,
> + &fw_mod_params[param_index].fw_init_baudrate);
> + } else {
> + BT_ERR("Unknown tag: %s", label);
> + ret = -1;
> + goto err;
> + }

Your indent is way too deep here, refactor the line processing into
another function to make it readable?

Wouldn't something like sscanf() make it a bit simpler?

> + }
> + } else {
> + BT_ERR("Invalid \"key\" = \"value\" pair at line: %d",
> + line_num - 1);
> + }
> + dptr = line;
> + } else {
> + *dptr = sptr[i];
> + dptr++;

What prevents dptr becoming larger than the size allocated for line?

> + }
> + }
> + /* '}' not found till the end of the file */
> + if (valid_param) {
> + BT_ERR("Expecting a '}' before the end of the file");
> + ret = -1;
> + goto err;
> + }
> +err:
> + return ret;
> +}
> +
> +static int nxp_load_fw_params_for_chip_id(u16 chip_id, struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + int i;
> +
> + for (i = 0; i < MAX_NO_OF_CHIPS_SUPPORT; i++) {
> + if (chip_id == fw_mod_params[i].chip_id) {

reverse if condition and use continue, and and you can lower indent for
these:

> + strncpy(nxpdev->fw_name, fw_mod_params[i].fw_name, MAX_FW_FILE_NAME_LEN);
> + nxpdev->oper_speed = fw_mod_params[i].oper_speed;
> + nxpdev->fw_dnld_pri_baudrate = fw_mod_params[i].fw_dnld_pri_baudrate;
> + nxpdev->fw_dnld_sec_baudrate = fw_mod_params[i].fw_dnld_sec_baudrate;
> + nxpdev->fw_init_baudrate = fw_mod_params[i].fw_init_baudrate;
> + break;
> + }
> + }
> + if (i == MAX_NO_OF_CHIPS_SUPPORT) {
> + if (chip_id == 0xffff)
> + BT_ERR("%s does not contain entry for 'legacy_chip'", BT_FW_CONF_FILE);
> + else
> + BT_ERR("Unsupported chip signature: %04X", chip_id);
> + clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
> + return -ENOENT;
> + }
> + return 0;
> +}
> +
> +static int nxp_download_firmware(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
> + int err = 0;
> +
> + nxpdev->fw_dnld_offset = 0;
> + nxpdev->fw_sent_bytes = 0;
> +
> + crc8_populate_msb(crc8_table, POLYNOMIAL8);
> +
> + serdev_device_set_baudrate(nxpdev->serdev, nxp_data->fw_dnld_pri_baudrate);
> + serdev_device_set_flow_control(nxpdev->serdev, 0);
> + set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
> + nxpdev->current_baudrate = nxp_data->fw_dnld_pri_baudrate;
> + nxpdev->fw_v3_offset_correction = 0;
> +
> + /* Wait till FW is downloaded and CTS becomes low */
> + init_waitqueue_head(&nxpdev->suspend_wait_q);
> + err = wait_event_interruptible_timeout(nxpdev->suspend_wait_q,
> + !test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state),
> + msecs_to_jiffies(60000));
> + if (err == 0) {
> + BT_ERR("FW Download Timeout.");
> + return -ETIMEDOUT;
> + }
> +
> + err = serdev_device_wait_for_cts(nxpdev->serdev, 1, 60000);
> + if (err < 0) {
> + BT_ERR("CTS is still high. FW Download failed.");
> + return err;
> + }
> + BT_INFO("CTS is low");
> + release_firmware(nxpdev->fw);
> +
> + /* Allow the downloaded FW to initialize */
> + usleep_range(20000, 22000);
> +
> + return 0;
> +}
> +
> +static int nxp_send_ack(u8 ack, struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + u8 ack_nak[2];
> +
> + if (ack == NXP_ACK_V1 || ack == NXP_NAK_V1) {
> + ack_nak[0] = ack;
> + serdev_device_write_buf(nxpdev->serdev, ack_nak, 1);
> + } else if (ack == NXP_ACK_V3) {
> + ack_nak[0] = ack;
> + ack_nak[1] = crc8(crc8_table, ack_nak, 1, 0xFF);
> + serdev_device_write_buf(nxpdev->serdev, ack_nak, 2);
> + }
> + return 0;
> +}
> +
> +static void nxp_fw_dnld_gen_crc_table(void)
> +{
> + int i, j;
> + unsigned long crc_accum;
> +
> + for (i = 0; i < 256; i++) {
> + crc_accum = ((unsigned long)i << 24);
> + for (j = 0; j < 8; j++) {
> + if (crc_accum & 0x80000000L)
> + crc_accum = (crc_accum << 1) ^ POLYNOMIAL32;
> + else
> + crc_accum = (crc_accum << 1);
> + }
> + crc32_table[i] = crc_accum;
> + }
> +}
> +
> +static unsigned long nxp_fw_dnld_update_crc(unsigned long crc_accum,
> + char *data_blk_ptr,
> + int data_blk_size)
> +{
> + unsigned long i, j;
> +
> + for (j = 0; j < data_blk_size; j++) {
> + i = ((unsigned long)(crc_accum >> 24) ^ *data_blk_ptr++) & 0xff;
> + crc_accum = (crc_accum << 8) ^ crc32_table[i];
> + }
> + return crc_accum;
> +}
> +
> +static bool nxp_fw_change_baudrate(struct hci_dev *hdev, u16 req_len)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + static u8 nxp_cmd5_header[HDR_LEN] = {

It would be good to prefix HDR_LEN with something to make it more specific
to this use case.

> + 0x05, 0x00, 0x00, 0x00,
> + 0x00, 0x00, 0x00, 0x00,
> + 0x2c, 0x00, 0x00, 0x00,
> + 0x77, 0xdb, 0xfd, 0xe0};
> + static u8 uart_config[60] = {0};

Is this some structure actually? You seem to be filling it always with
the same stuff in same order?

You probably need to handle byte-order properly too.

> + u32 header_len = 0;
> + u32 uart_config_len = 0;
> + u32 mcr = MCR;
> + u32 init = INIT;
> + u32 icr = ICR;
> + u32 fcr = FCR;
> + u32 br_addr = CLKDIVADDR;
> + u32 div_addr = UARTDIVADDR;
> + u32 mcr_addr = UARTMCRADDR;
> + u32 re_init_addr = UARTREINITADDR;
> + u32 icr_addr = UARTICRADDR;
> + u32 fcr_addr = UARTFCRADDR;
> + u32 uart_div = 1;
> + u32 uart_clk = 0x00C00000;
> + u32 crc = 0;
> + bool ret = false;
> +
> + nxpdev->fw_v3_offset_correction += req_len;
> +
> + if (req_len == HDR_LEN) {
> + /* Create CMD5 payload */
> + memcpy(uart_config + uart_config_len, &br_addr, sizeof(br_addr));
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &uart_clk, sizeof(uart_clk));
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &div_addr, 4);

Why only part use sizeof and this one doesn't but you should probably
convert struct and proper byte-order handling anyway so addressing this
comment is likely irrelevant.

> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &uart_div, 4);
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &mcr_addr, 4);
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &mcr, 4);
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &re_init_addr, 4);
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &init, 4);
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &icr_addr, 4);
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &icr, 4);
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &fcr_addr, 4);
> + uart_config_len += 4;
> + memcpy(uart_config + uart_config_len, &fcr, 4);
> + uart_config_len += 4;
> + header_len = uart_config_len + 4;
> +
> + nxp_fw_dnld_gen_crc_table();
> +
> + /* Calculate CRC for CMD5 Header */
> + memcpy(nxp_cmd5_header + 8, &header_len, sizeof(header_len));
> + crc = (u32)nxp_fw_dnld_update_crc(0UL, nxp_cmd5_header, 12);
> + crc = (u32)SWAPL(crc);
> + memcpy(nxp_cmd5_header + 12, &crc, 4);
> +
> + /* Calculate CRC for CMD5 Payload */
> + crc = (u32)nxp_fw_dnld_update_crc(0UL, uart_config, uart_config_len);
> + crc = (u32)SWAPL(crc);
> + memcpy(uart_config + uart_config_len, &crc, 4);
> + uart_config_len += 4;
> +
> + serdev_device_write_buf(nxpdev->serdev, nxp_cmd5_header, req_len);
> + } else {
> + serdev_device_write_buf(nxpdev->serdev, uart_config, req_len);
> + serdev_device_wait_until_sent(nxpdev->serdev, 0);
> + ret = true;
> + }
> + return ret;
> +}
> +
> +static bool nxp_fw_change_timeout(struct hci_dev *hdev, u16 req_len)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + bool ret = false;
> + u8 nxp_cmd7_header[HDR_LEN] = {0x07, 0x00, 0x00, 0x00,
> + 0x70, 0x00, 0x00, 0x00,
> + 0x00, 0x00, 0x00, 0x00,
> + 0x5b, 0x88, 0xf8, 0xba};

Fix indentation.

> +
> + nxpdev->fw_v3_offset_correction += req_len;
> +
> + if (req_len == HDR_LEN) {
> + serdev_device_write_buf(nxpdev->serdev, nxp_cmd7_header, req_len);
> + serdev_device_wait_until_sent(nxpdev->serdev, 0);
> + ret = true;
> + }
> + return ret;

Just use return true and return false directly.

> +}
> +
> +static u32 nxp_get_data_len(const u8 *buf)
> +{
> + return (buf[8] | (buf[9] << 8));

Custom byte-order func? Use std ones instead.

> +}
> +
> +/* for legacy chipsets with V1 bootloader */
> +static int nxp_recv_fw_req_v1(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + struct V1_DATA_REQ *req = skb_pull_data(skb, sizeof(struct V1_DATA_REQ));
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
> + static bool timeout_changed;
> + static bool baudrate_changed;
> + u32 requested_len;
> + static u32 expected_len = HDR_LEN;
> + int err;
> +
> + if (!test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state))
> + return 0;
> +
> + if (strlen(nxpdev->fw_name) == 0) {
> + err = nxp_load_fw_params_for_chip_id(0xffff, hdev);
> + if (err < 0)
> + return err;
> + timeout_changed = false;
> + baudrate_changed = false;
> + /* If secondary baudrate is not read from
> + * the conf file set default value from nxp_data
> + */
> + if (nxpdev->fw_dnld_sec_baudrate == 0)
> + nxpdev->fw_dnld_sec_baudrate = nxp_data->fw_dnld_sec_baudrate;
> + }
> +
> + if (nxpdev->fw_dnld_sec_baudrate != nxpdev->current_baudrate) {
> + if (!timeout_changed) {
> + nxp_send_ack(NXP_ACK_V1, hdev);
> + timeout_changed = nxp_fw_change_timeout(hdev, req->len);

You never test if there was enough data? If there isn't req will be NULL
which you don't check before dereferencing req->len.

> + return 0;
> + }
> + if (!baudrate_changed) {
> + nxp_send_ack(NXP_ACK_V1, hdev);
> + baudrate_changed = nxp_fw_change_baudrate(hdev, req->len);

Ditto.

> + if (baudrate_changed) {
> + serdev_device_set_baudrate(nxpdev->serdev,
> + nxpdev->fw_dnld_sec_baudrate);
> + nxpdev->current_baudrate = nxpdev->fw_dnld_sec_baudrate;
> + }
> + return 0;
> + }
> + }
> +
> + if (!nxpdev->fw) {
> + BT_INFO("Request Firmware: %s", nxpdev->fw_name);
> + err = request_firmware(&nxpdev->fw, nxpdev->fw_name, &hdev->dev);
> + if (err < 0) {
> + BT_ERR("Firmware file %s not found", nxpdev->fw_name);
> + clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
> + return err;
> + }
> + }
> +
> + if (req && (req->len ^ req->len_comp) == 0xffff) {
> + nxp_send_ack(NXP_ACK_V1, hdev);
> + if (req->len == 0) {
> + BT_INFO("FW_Downloaded Successfully: %ld bytes", nxpdev->fw->size);
> + clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
> + wake_up_interruptible(&nxpdev->suspend_wait_q);
> + return 0;
> + }
> + if (req->len & 0x01) {
> + /* The CRC did not match at the other end.
> + * That's why the request to re-send.
> + * Simply send the same bytes again.
> + */
> + requested_len = nxpdev->fw_sent_bytes;
> + BT_ERR("CRC error. Resend %d bytes of FW.", requested_len);
> + } else {
> + /* Increment offset by number of previous successfully sent bytes */
> + nxpdev->fw_dnld_offset += nxpdev->fw_sent_bytes;
> + requested_len = req->len;
> + }
> +
> + /* The FW bin file is made up of many blocks of
> + * 16 byte header and payload data chunks. If the
> + * FW has requested a header, read the payload length
> + * info from the header, and then send the header.
> + * In the next iteration, the FW should request the
> + * payload data chunk, which should be equal to the
> + * payload length read from header. If there is a
> + * mismatch, clearly the driver and FW are out of sync,
> + * and we need to re-send the previous header again.
> + */
> + if (requested_len == expected_len) {
> + if (requested_len == HDR_LEN)
> + expected_len = nxp_get_data_len(nxpdev->fw->data +
> + nxpdev->fw_dnld_offset);
> + else
> + expected_len = HDR_LEN;

How can you ever end up into this else branch? Why assign expected_len
here?

> + } else {
> + if (requested_len == HDR_LEN) {

Never true.

> + /* FW download out of sync. Send previous chunk again */
> + nxpdev->fw_dnld_offset -= nxpdev->fw_sent_bytes;
> + expected_len = HDR_LEN;
> + }
> + }
> +
> + if (nxpdev->fw_dnld_offset + requested_len <= nxpdev->fw->size)
> + serdev_device_write_buf(nxpdev->serdev,
> + nxpdev->fw->data + nxpdev->fw_dnld_offset,
> + requested_len);
> + nxpdev->fw_sent_bytes = requested_len;
> + } else {
> + BT_INFO("ERR: Send NAK");
> + nxp_send_ack(NXP_NAK_V1, hdev);
> + }
> + return 0;
> +}
> +
> +static int nxp_recv_chip_ver_v3(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + struct V3_START_IND *req = skb_pull_data(skb, sizeof(struct V3_START_IND));
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
> + int err = 0;
> +
> + if (!test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state))
> + return 0;
> +
> + if (req) {
> + if (strlen(nxpdev->fw_name) == 0) {
> + nxp_load_fw_params_for_chip_id(req->chip_id, hdev);
> + } else if (!nxpdev->fw) {
> + BT_INFO("Request Firmware: %s", nxpdev->fw_name);
> + err = request_firmware(&nxpdev->fw, nxpdev->fw_name, &hdev->dev);
> + if (err < 0) {
> + BT_ERR("Firmware file %s not found", nxpdev->fw_name);
> + clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
> + }
> + } else {
> + /* If secondary baudrate is not read from
> + * the conf file set default value from nxp_data
> + */
> + if (nxpdev->fw_dnld_sec_baudrate == 0)
> + nxpdev->fw_dnld_sec_baudrate = nxp_data->fw_dnld_sec_baudrate;
> + nxp_send_ack(NXP_ACK_V3, hdev);
> + }
> + }
> + return err;
> +}
> +
> +static int nxp_recv_fw_req_v3(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + struct V3_DATA_REQ *req = skb_pull_data(skb, sizeof(struct V3_DATA_REQ));
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + static bool timeout_changed;
> + static bool baudrate_changed;
> +
> + if (!req || !nxpdev || !strlen(nxpdev->fw_name) || !nxpdev->fw->data)
> + return 0;

Who is expected to free the skb? These functions or one of the callers?
(Which one? I lost track of the callchain and error passing too).

> +
> + if (!test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state))
> + return 0;
> +
> + nxp_send_ack(NXP_ACK_V3, hdev);
> +
> + if (nxpdev->fw_dnld_sec_baudrate != nxpdev->current_baudrate) {
> + if (!timeout_changed) {
> + timeout_changed = nxp_fw_change_timeout(hdev, req->len);
> + return 0;
> + }
> +
> + if (!baudrate_changed) {
> + baudrate_changed = nxp_fw_change_baudrate(hdev, req->len);
> + if (baudrate_changed) {
> + serdev_device_set_baudrate(nxpdev->serdev,
> + nxpdev->fw_dnld_sec_baudrate);
> + nxpdev->current_baudrate = nxpdev->fw_dnld_sec_baudrate;
> + }
> + return 0;
> + }
> + }
> +
> + if (req->len == 0) {
> + BT_INFO("FW_Downloaded Successfully: %ld bytes", nxpdev->fw->size);
> + clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
> + wake_up_interruptible(&nxpdev->suspend_wait_q);
> + return 0;
> + }
> + if (req->error)
> + BT_ERR("FW Download received err 0x%02X from chip. Resending FW chunk.",
> + req->error);
> +
> + if (req->offset < nxpdev->fw_v3_offset_correction) {
> + /* This scenario should ideally never occur.
> + * But if it ever does, FW is out of sync and
> + * needs a power cycle.
> + */
> + BT_ERR("Something went wrong during FW download. Please power cycle and try again");
> + return 0;
> + }
> +
> + serdev_device_write_buf(nxpdev->serdev,
> + nxpdev->fw->data + req->offset - nxpdev->fw_v3_offset_correction,
> + req->len);
> +
> + return 0;
> +}
> +
> +static int nxp_set_baudrate_cmd(struct hci_dev *hdev, void *data)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + struct ps_data *psdata = nxpdev->psdata;
> + u8 *pcmd = (u8 *)&nxpdev->new_baudrate;
> + struct sk_buff *skb;
> + u8 *status;
> + int ret = 0;
> +
> + if (!psdata)
> + return -EFAULT;
> +
> + psdata->driver_sent_cmd = true; /* set flag to prevent re-sending command in nxp_enqueue */
> + skb = __hci_cmd_sync(hdev, HCI_NXP_SET_OPER_SPEED, 4, pcmd, HCI_CMD_TIMEOUT);
> + psdata->driver_sent_cmd = false;

Yeah, this is third one so make a helper for this. Why is this assigning
true/false to a u8 member btw?

> +
> + if (IS_ERR(skb)) {
> + bt_dev_err(hdev, "Setting baudrate failed (%ld)",
> + PTR_ERR(skb));

One line.

> + return PTR_ERR(skb);
> + }
> +
> + status = skb_pull_data(skb, 1);
> + if (status) {
> + if (*status == 0) {
> + serdev_device_set_baudrate(nxpdev->serdev, nxpdev->new_baudrate);
> + nxpdev->current_baudrate = nxpdev->new_baudrate;
> + }
> + ret = *status;
> + BT_INFO("Set baudrate response: status=%d, baudrate=%d",
> + *status, nxpdev->new_baudrate);

return *status;

> + }
> +
> + return ret;

return 0;

drop ret variable

> +}
> +
> +/* NXP protocol */
> +static int nxp_setup(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
> + const char *fw_name_dt;
> + const char *fw_path = "nxp/";
> + int ret = 0;
> +
> + if (!serdev_device_get_cts(nxpdev->serdev)) {
> + BT_INFO("CTS high. Need FW Download");
> +
> + /* Try reading FW name from DT */
> + if (!device_property_read_string(&nxpdev->serdev->dev, "firmware-name",
> + &fw_name_dt)) {
> + strncpy(nxpdev->fw_name, fw_path, MAX_FW_FILE_NAME_LEN);
> + strncpy(nxpdev->fw_name + strlen(fw_path), fw_name_dt,
> + MAX_FW_FILE_NAME_LEN);

How can this second one be correct if you use +strlen(fw_path) for the
pointer. Why not use snprintf()?

> + } else {
> + /* If no input from DT, parse conf file from user-space.
> + * FW name will be selected based on the chip bootloader
> + * signature read, and corresponding entry in conf file.
> + */
> + ret = request_firmware(&nxpdev->fw_config, BT_FW_CONF_FILE, &hdev->dev);
> + if (ret < 0) {
> + BT_INFO("Firmware conf file not found: %s", BT_FW_CONF_FILE);
> + clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
> + goto err;
> + }
> + ret = nxp_parse_conf_file(hdev);
> + release_firmware(nxpdev->fw_config);
> + if (ret < 0) {
> + BT_ERR("Error parsing config file: %s", BT_FW_CONF_FILE);
> + goto err;
> + }
> + }
> +
> + ret = nxp_download_firmware(hdev);
> + if (ret < 0)
> + goto err;
> + } else {
> + BT_INFO("CTS low. FW already running.");
> + }
> +
> + serdev_device_set_flow_control(nxpdev->serdev, 1);
> +
> + /* If fw_init_baudrate is not read from
> + * the conf file set default value from nxp_data
> + */
> + if (nxpdev->fw_init_baudrate == 0)

if (!xx)

> + nxpdev->fw_init_baudrate = nxp_data->fw_init_baudrate;
> + serdev_device_set_baudrate(nxpdev->serdev, nxpdev->fw_init_baudrate);
> + nxpdev->current_baudrate = nxpdev->fw_init_baudrate;
> +
> + /* If oper_speed is not read from
> + * the conf file set default value from nxp_data
> + */
> + if (nxpdev->oper_speed == 0)

Ditto.

> + nxpdev->oper_speed = nxp_data->oper_speed;
> +
> + if (nxpdev->current_baudrate != nxpdev->oper_speed) {
> + /* Queue cmd to set baudrate to oper-speed */
> + nxpdev->new_baudrate = nxpdev->oper_speed;
> + hci_cmd_sync_queue(hdev, nxp_set_baudrate_cmd, NULL, NULL);
> + }
> +
> + if (ps_init_work(hdev) == 0)

Ditto.

> + ps_init_timer(hdev);
> + ps_init(hdev);
> +err:
> + return ret;
> +}
> +
> +static int nxp_enqueue(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + struct ps_data *psdata = nxpdev->psdata;
> + struct hci_command_hdr *hdr;
> + u8 *param;
> +
> + /* if commands are received from user space (e.g. hcitool), update
> + * driver flags accordingly and ask driver to re-send the command
> + */
> + if (bt_cb(skb)->pkt_type == HCI_COMMAND_PKT && !psdata->driver_sent_cmd) {

Should you need to check psdata for NULL before dereferencing it?

> + hdr = (struct hci_command_hdr *)skb->data;
> + param = skb->data + HCI_COMMAND_HDR_SIZE;
> + switch (__le16_to_cpu(hdr->opcode)) {
> + case HCI_NXP_AUTO_SLEEP_MODE:
> + if (hdr->plen >= 1) {
> + if (param[0] == BT_PS_ENABLE)
> + psdata->ps_mode = PS_MODE_ENABLE;
> + else if (param[0] == BT_PS_DISABLE)
> + psdata->ps_mode = PS_MODE_DISABLE;
> + hci_cmd_sync_queue(hdev, send_ps_cmd, NULL, NULL);
> + kfree_skb(skb);
> + goto ret;
> + }
> + break;
> + case HCI_NXP_WAKEUP_METHOD:
> + if (hdr->plen >= 4) {
> + switch (param[2]) {
> + case BT_CTRL_WAKEUP_METHOD_DSR:
> + psdata->wakeupmode = WAKEUP_METHOD_DTR;
> + break;
> + case BT_CTRL_WAKEUP_METHOD_BREAK:
> + default:
> + psdata->wakeupmode = WAKEUP_METHOD_BREAK;
> + break;
> + }
> + hci_cmd_sync_queue(hdev, send_wakeup_method_cmd, NULL, NULL);
> + kfree_skb(skb);
> + goto ret;
> + }
> + break;
> + case HCI_NXP_SET_OPER_SPEED:
> + if (hdr->plen == 4) {
> + nxpdev->new_baudrate = *((u32 *)param);
> + hci_cmd_sync_queue(hdev, nxp_set_baudrate_cmd, NULL, NULL);
> + kfree_skb(skb);
> + goto ret;
> + }
> + }
> + }
> +
> + /* Prepend skb with frame type */
> + memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
> + skb_queue_tail(&nxpdev->txq, skb);
> +
> + btnxpuart_tx_wakeup(nxpdev);
> +ret:
> + return 0;
> +}
> +
> +static struct sk_buff *nxp_dequeue(void *data)
> +{
> + struct btnxpuart_dev *nxpdev = (struct btnxpuart_dev *)data;
> +
> + ps_wakeup(nxpdev);
> + ps_start_timer(nxpdev);
> + return skb_dequeue(&nxpdev->txq);
> +}
> +
> +/* btnxpuart based on serdev */
> +static void btnxpuart_tx_work(struct work_struct *work)
> +{
> + struct btnxpuart_dev *nxpdev = container_of(work, struct btnxpuart_dev,
> + tx_work);
> + struct serdev_device *serdev = nxpdev->serdev;
> + struct hci_dev *hdev = nxpdev->hdev;
> +
> + if (!nxpdev->nxp_data->dequeue)
> + return;
> +
> + while (1) {
> + clear_bit(BTNXPUART_TX_STATE_WAKEUP, &nxpdev->tx_state);
> +
> + while (1) {
> + struct sk_buff *skb = nxpdev->nxp_data->dequeue(nxpdev);
> + int len;
> +
> + if (!skb)
> + break;
> +
> + len = serdev_device_write_buf(serdev, skb->data,
> + skb->len);

One line.

> + hdev->stat.byte_tx += len;
> +
> + skb_pull(skb, len);
> + if (skb->len > 0) {
> + skb_queue_head(&nxpdev->txq, skb);
> + break;
> + }
> +
> + switch (hci_skb_pkt_type(skb)) {
> + case HCI_COMMAND_PKT:
> + hdev->stat.cmd_tx++;
> + break;
> + case HCI_ACLDATA_PKT:
> + hdev->stat.acl_tx++;
> + break;
> + case HCI_SCODATA_PKT:
> + hdev->stat.sco_tx++;
> + break;
> + }
> +
> + kfree_skb(skb);
> + }
> +
> + if (!test_bit(BTNXPUART_TX_STATE_WAKEUP, &nxpdev->tx_state))
> + break;
> + }
> + clear_bit(BTNXPUART_TX_STATE_ACTIVE, &nxpdev->tx_state);
> +}
> +
> +static void btnxpuart_tx_wakeup(struct btnxpuart_dev *nxpdev)
> +{
> + if (test_and_set_bit(BTNXPUART_TX_STATE_ACTIVE, &nxpdev->tx_state)) {
> + set_bit(BTNXPUART_TX_STATE_WAKEUP, &nxpdev->tx_state);
> + return;
> + }
> + schedule_work(&nxpdev->tx_work);
> +}
> +
> +static int btnxpuart_open(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + int err;
> +
> + err = serdev_device_open(nxpdev->serdev);
> + if (err) {
> + bt_dev_err(hdev, "Unable to open UART device %s",
> + dev_name(&nxpdev->serdev->dev));
> + return err;
> + }
> +
> + if (nxpdev->nxp_data->open) {
> + err = nxpdev->nxp_data->open(hdev);
> + if (err) {
> + serdev_device_close(nxpdev->serdev);
> + return err;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int btnxpuart_close(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> + int err;
> +
> + if (nxpdev->nxp_data->close) {
> + err = nxpdev->nxp_data->close(hdev);
> + if (err)
> + return err;
> + }
> +
> + serdev_device_close(nxpdev->serdev);
> +
> + return 0;
> +}
> +
> +static int btnxpuart_flush(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> +
> + /* Flush any pending characters */
> + serdev_device_write_flush(nxpdev->serdev);
> + skb_queue_purge(&nxpdev->txq);
> +
> + cancel_work_sync(&nxpdev->tx_work);
> +
> + kfree_skb(nxpdev->rx_skb);
> + nxpdev->rx_skb = NULL;
> +
> + return 0;
> +}
> +
> +static int btnxpuart_setup(struct hci_dev *hdev)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> +
> + if (nxpdev->nxp_data->setup)
> + return nxpdev->nxp_data->setup(hdev);
> +
> + return 0;
> +}
> +
> +static int btnxpuart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> + struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
> +
> + if (nxpdev->nxp_data->enqueue)
> + nxpdev->nxp_data->enqueue(hdev, skb);
> +
> + return 0;
> +}
> +
> +static int btnxpuart_receive_buf(struct serdev_device *serdev, const u8 *data,
> + size_t count)
> +{
> + struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
> + const struct btnxpuart_data *nxp_data = nxpdev->nxp_data;
> +
> + if (test_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state)) {
> + if (*data != NXP_V1_FW_REQ_PKT && *data != NXP_V1_CHIP_VER_PKT &&
> + *data != NXP_V3_FW_REQ_PKT && *data != NXP_V3_CHIP_VER_PKT) {

Fix indent.

> + /* Unknown bootloader signature, skip without returning error */
> + return count;
> + }
> + }
> +
> + ps_start_timer(nxpdev);
> +
> + nxpdev->rx_skb = h4_recv_buf(nxpdev->hdev, nxpdev->rx_skb, data, count,
> + nxp_data->recv_pkts, nxp_data->recv_pkts_cnt);
> + if (IS_ERR(nxpdev->rx_skb)) {
> + int err = PTR_ERR(nxpdev->rx_skb);
> +
> + bt_dev_err(nxpdev->hdev, "Frame reassembly failed (%d)", err);
> + nxpdev->rx_skb = NULL;
> + return err;
> + }
> + nxpdev->hdev->stat.byte_rx += count;
> + return count;
> +}
> +
> +static void btnxpuart_write_wakeup(struct serdev_device *serdev)
> +{
> + serdev_device_write_wakeup(serdev);
> +}
> +
> +static const struct serdev_device_ops btnxpuart_client_ops = {
> + .receive_buf = btnxpuart_receive_buf,
> + .write_wakeup = btnxpuart_write_wakeup,
> +};
> +
> +static int nxp_serdev_probe(struct serdev_device *serdev)
> +{
> + struct hci_dev *hdev;
> + struct btnxpuart_dev *nxpdev;
> +
> + nxpdev = devm_kzalloc(&serdev->dev, sizeof(*nxpdev), GFP_KERNEL);
> + if (!nxpdev)
> + return -ENOMEM;
> +
> + memset(nxpdev, 0, sizeof(*nxpdev));

Memsetting kzalloc'ed mem.

> +
> + nxpdev->nxp_data = device_get_match_data(&serdev->dev);
> +
> + nxpdev->serdev = serdev;
> + serdev_device_set_drvdata(serdev, nxpdev);
> +
> + serdev_device_set_client_ops(serdev, &btnxpuart_client_ops);
> +
> + INIT_WORK(&nxpdev->tx_work, btnxpuart_tx_work);
> + skb_queue_head_init(&nxpdev->txq);
> +
> + /* Initialize and register HCI device */
> + hdev = hci_alloc_dev();
> + if (!hdev) {
> + dev_err(&serdev->dev, "Can't allocate HCI device\n");
> + return -ENOMEM;
> + }
> +
> + nxpdev->hdev = hdev;
> +
> + hdev->bus = HCI_UART;
> + hci_set_drvdata(hdev, nxpdev);
> +
> + /* Only when vendor specific setup callback is provided, consider
> + * the manufacturer information valid. This avoids filling in the
> + * value for NXP when nothing is specified.
> + */
> + if (nxpdev->nxp_data->setup)
> + hdev->manufacturer = nxpdev->nxp_data->manufacturer;
> +
> + hdev->open = btnxpuart_open;
> + hdev->close = btnxpuart_close;
> + hdev->flush = btnxpuart_flush;
> + hdev->setup = btnxpuart_setup;
> + hdev->send = btnxpuart_send_frame;
> + SET_HCIDEV_DEV(hdev, &serdev->dev);
> +
> + if (hci_register_dev(hdev) < 0) {
> + dev_err(&serdev->dev, "Can't register HCI device\n");
> + hci_free_dev(hdev);
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +static void nxp_serdev_remove(struct serdev_device *serdev)
> +{
> + struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
> + struct hci_dev *hdev = nxpdev->hdev;
> +
> + /* Restore FW baudrate to fw_init_baudrate if changed.
> + * This will ensure FW baudrate is in sync with
> + * driver baudrate in case this driver is re-inserted.
> + */
> + if (nxpdev->fw_init_baudrate != nxpdev->current_baudrate) {
> + nxpdev->new_baudrate = nxpdev->fw_init_baudrate;
> + nxp_set_baudrate_cmd(hdev, NULL);
> + }
> +
> + ps_cancel_timer(nxpdev);
> + hci_unregister_dev(hdev);
> + hci_free_dev(hdev);
> +}
> +
> +static const struct h4_recv_pkt nxp_recv_pkts[] = {
> + { H4_RECV_ACL, .recv = hci_recv_frame },
> + { H4_RECV_SCO, .recv = hci_recv_frame },
> + { H4_RECV_EVENT, .recv = hci_recv_frame },
> + { NXP_RECV_FW_REQ_V1, .recv = nxp_recv_fw_req_v1 },
> + { NXP_RECV_CHIP_VER_V3, .recv = nxp_recv_chip_ver_v3 },
> + { NXP_RECV_FW_REQ_V3, .recv = nxp_recv_fw_req_v3 },
> +};
> +
> +static const struct btnxpuart_data nxp_generic_data = {
> + .recv_pkts = nxp_recv_pkts,
> + .recv_pkts_cnt = ARRAY_SIZE(nxp_recv_pkts),
> + .manufacturer = 18,
> + .fw_dnld_pri_baudrate = 115200,
> + .fw_dnld_sec_baudrate = 3000000,
> + .fw_init_baudrate = 3000000,
> + .oper_speed = 3000000,
> + .setup = nxp_setup,
> + .enqueue = nxp_enqueue,
> + .dequeue = nxp_dequeue,
> +};
> +
> +static const struct btnxpuart_data nxp_legacy_data = {
> + .recv_pkts = nxp_recv_pkts,
> + .recv_pkts_cnt = ARRAY_SIZE(nxp_recv_pkts),
> + .manufacturer = 18,
> + .fw_dnld_pri_baudrate = 115200,
> + .fw_dnld_sec_baudrate = 3000000,
> + .fw_init_baudrate = 115200,
> + .oper_speed = 3000000,
> + .setup = nxp_setup,
> + .enqueue = nxp_enqueue,
> + .dequeue = nxp_dequeue,
> +};
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id nxpuart_of_match_table[] = {
> + { .compatible = "nxp,nxp-generic-bt-chip", .data = &nxp_generic_data },
> + { .compatible = "nxp,nxp-legacy-bt-chip", .data = &nxp_legacy_data },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, nxpuart_of_match_table);
> +#endif
> +
> +static struct serdev_device_driver nxp_serdev_driver = {
> + .probe = nxp_serdev_probe,
> + .remove = nxp_serdev_remove,
> + .driver = {
> + .name = "btnxpuart",
> + .of_match_table = of_match_ptr(nxpuart_of_match_table),
> + },
> +};
> +
> +module_serdev_device_driver(nxp_serdev_driver);
> +
> +MODULE_AUTHOR("Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>");
> +MODULE_DESCRIPTION("NXP Bluetooth Serial driver v1.0 ");
> +MODULE_VERSION("v1.0");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/bluetooth/btnxp.h b/drivers/bluetooth/btnxp.h
> new file mode 100644
> index 000000000000..23ab11c1ce8d
> --- /dev/null
> +++ b/drivers/bluetooth/btnxp.h
> @@ -0,0 +1,230 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + *
> + * NXP Bluetooth driver
> + * Copyright 2018-2023 NXP
> + *
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#ifndef BT_NXP_H_
> +#define BT_NXP_H_
> +
> +#define BT_FW_CONF_FILE "nxp/bt_mod_para.conf"
> +#define FW_NAME_TAG "fw_name"
> +#define OPER_SPEED_TAG "oper_speed"
> +#define FW_DL_PRI_BAUDRATE_TAG "fw_dl_pri_speed"
> +#define FW_DL_SEC_BAUDRATE_TAG "fw_dl_sec_speed"
> +#define FW_INIT_BAUDRATE "fw_init_speed"
> +
> +#define MAX_CHIP_NAME_LEN 20
> +#define MAX_FW_FILE_NAME_LEN 50
> +#define MAX_NO_OF_CHIPS_SUPPORT 20
> +
> +/* Default ps timeout period in milli-second */
> +#define PS_DEFAULT_TIMEOUT_PERIOD 2000
> +
> +/* wakeup methods */
> +#define WAKEUP_METHOD_DTR 0
> +#define WAKEUP_METHOD_BREAK 1
> +#define WAKEUP_METHOD_EXT_BREAK 2
> +#define WAKEUP_METHOD_RTS 3
> +#define WAKEUP_METHOD_INVALID 0xff
> +
> +/* power save mode status */
> +#define PS_MODE_DISABLE 0
> +#define PS_MODE_ENABLE 1
> +
> +/* Power Save Commands to ps_work_func */
> +#define PS_CMD_EXIT_PS 1
> +#define PS_CMD_ENTER_PS 2
> +
> +/* power save state */
> +#define PS_STATE_AWAKE 0
> +#define PS_STATE_SLEEP 1
> +
> +/* Bluetooth vendor command : Sleep mode */
> +#define HCI_NXP_AUTO_SLEEP_MODE 0xFC23

Try to change all hex letters to lowercase.

> +/* Bluetooth vendor command : Wakeup method */
> +#define HCI_NXP_WAKEUP_METHOD 0xFC53
> +/* Bluetooth vendor command : Set operational baudrate */
> +#define HCI_NXP_SET_OPER_SPEED 0xFC09
> +
> +/* Bluetooth Power State : Vendor cmd params */
> +#define BT_PS_ENABLE 0x02
> +#define BT_PS_DISABLE 0x03
> +
> +/* Bluetooth Host Wakeup Methods */
> +#define BT_HOST_WAKEUP_METHOD_NONE 0x00
> +#define BT_HOST_WAKEUP_METHOD_DTR 0x01
> +#define BT_HOST_WAKEUP_METHOD_BREAK 0x02
> +#define BT_HOST_WAKEUP_METHOD_GPIO 0x03
> +#define BT_HOST_WAKEUP_DEFAULT_GPIO 5
> +
> +/* Bluetooth Chip Wakeup Methods */
> +#define BT_CTRL_WAKEUP_METHOD_DSR 0x00
> +#define BT_CTRL_WAKEUP_METHOD_BREAK 0x01
> +#define BT_CTRL_WAKEUP_METHOD_GPIO 0x02
> +#define BT_CTRL_WAKEUP_METHOD_EXT_BREAK 0x04
> +#define BT_CTRL_WAKEUP_METHOD_RTS 0x05
> +#define BT_CTRL_WAKEUP_DEFAULT_GPIO 4
> +
> +struct ps_data {
> + u8 ps_mode;
> + u8 cur_psmode;
> + u8 ps_state;
> + u8 ps_cmd;
> + u8 wakeupmode;
> + u8 cur_wakeupmode;
> + u8 driver_sent_cmd;
> + u8 timer_on;
> + u32 interval;
> + struct hci_dev *hdev;
> + struct work_struct work;
> + struct timer_list ps_timer;
> +};
> +
> +struct btnxpuart_data {
> + const struct h4_recv_pkt *recv_pkts;
> + int recv_pkts_cnt;
> + unsigned int manufacturer;
> + int (*open)(struct hci_dev *hdev);
> + int (*close)(struct hci_dev *hdev);
> + int (*setup)(struct hci_dev *hdev);
> + int (*enqueue)(struct hci_dev *hdev, struct sk_buff *skb);
> + struct sk_buff *(*dequeue)(void *data);
> + u32 fw_dnld_pri_baudrate;
> + u32 fw_dnld_sec_baudrate;
> + u32 fw_init_baudrate;
> + u32 oper_speed;
> +};
> +
> +struct btnxpuart_dev {
> + struct hci_dev *hdev;
> + struct serdev_device *serdev;
> +
> + struct work_struct tx_work;
> + unsigned long tx_state;
> + struct sk_buff_head txq;
> + struct sk_buff *rx_skb;
> +
> + const struct firmware *fw;
> + const struct firmware *fw_config;
> + u8 fw_name[MAX_FW_FILE_NAME_LEN];
> + u32 fw_dnld_offset;
> + u32 fw_sent_bytes;
> + u32 fw_v3_offset_correction;
> + wait_queue_head_t suspend_wait_q;
> +
> + u32 fw_dnld_pri_baudrate;
> + u32 fw_dnld_sec_baudrate;
> + u32 fw_init_baudrate;
> + u32 oper_speed;
> + u32 new_baudrate;
> + u32 current_baudrate;
> +
> + struct ps_data *psdata;
> + const struct btnxpuart_data *nxp_data;
> +};
> +
> +struct chip_id_map_table {
> + u16 chip_id;
> + const u8 *chip_name;
> +};
> +
> +struct fw_params {
> + u16 chip_id;
> + u8 chip_name[MAX_CHIP_NAME_LEN];
> + u8 fw_name[MAX_FW_FILE_NAME_LEN];
> + u32 fw_dnld_pri_baudrate;
> + u32 fw_dnld_sec_baudrate;
> + u32 fw_init_baudrate;
> + u32 oper_speed;
> +};
> +
> +#define NXP_V1_FW_REQ_PKT 0xA5
> +#define NXP_V1_CHIP_VER_PKT 0xAA
> +#define NXP_V3_FW_REQ_PKT 0xA7
> +#define NXP_V3_CHIP_VER_PKT 0xAB
> +
> +#define NXP_ACK_V1 0x5A
> +#define NXP_NAK_V1 0xBF
> +#define NXP_ACK_V3 0x7A
> +#define NXP_NAK_V3 0x7B
> +#define NXP_CRC_ERROR_V3 0x7C
> +
> +#define HDR_LEN 16
> +
> +#define NXP_RECV_FW_REQ_V1 \
> + .type = NXP_V1_FW_REQ_PKT, \
> + .hlen = 4, \
> + .loff = 0, \
> + .lsize = 0, \
> + .maxlen = 4
> +
> +#define NXP_RECV_CHIP_VER_V3 \
> + .type = NXP_V3_CHIP_VER_PKT, \
> + .hlen = 4, \
> + .loff = 0, \
> + .lsize = 0, \
> + .maxlen = 4
> +
> +#define NXP_RECV_FW_REQ_V3 \
> + .type = NXP_V3_FW_REQ_PKT, \
> + .hlen = 9, \
> + .loff = 0, \
> + .lsize = 0, \
> + .maxlen = 9
> +
> +struct V1_DATA_REQ {
> + u16 len;
> + u16 len_comp;
> +} __packed;
> +
> +struct V3_DATA_REQ {
> + u16 len;
> + u32 offset;
> + u16 error;
> + u8 crc;
> +} __packed;
> +
> +struct V3_START_IND {
> + u16 chip_id;
> + u8 loader_ver;
> + u8 crc;
> +} __packed;

Struct names should be lowercased. Multibyte fields need to specify
byte-order?

> +/* UART register addresses of BT chip */
> +#define CLKDIVADDR 0x7f00008f
> +#define UARTDIVADDR 0x7f000090
> +#define UARTMCRADDR 0x7f000091
> +#define UARTREINITADDR 0x7f000092
> +#define UARTICRADDR 0x7f000093
> +#define UARTFCRADDR 0x7f000094
> +
> +#define MCR 0x00000022
> +#define INIT 0x00000001
> +#define ICR 0x000000c7
> +#define FCR 0x000000c7
> +
> +#define SWAPL(x) ((((x) >> 24) & 0xff) \
> + | (((x) >> 8) & 0xff00) \
> + | (((x) << 8) & 0xff0000L) \
> + | (((x) << 24) & 0xff000000L))

Perhaps something existing under include/ could do swap for you?

> +
> +#define POLYNOMIAL8 0x07
> +#define POLYNOMIAL32 0x04c11db7L
> +
> +static void btnxpuart_tx_wakeup(struct btnxpuart_dev *nxpdev);
> +
> +#endif
>

--
i.