Re: [PATCH v5] Bluetooth: NXP: Add protocol support for NXP Bluetooth chipsets

From: Greg KH
Date: Thu Feb 23 2023 - 05:48:22 EST


On Thu, Feb 23, 2023 at 04:06:14PM +0530, 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 an 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 over UART.
>
> This driver enables the power save feature by default by sending the vendor
> specific commands to the chip during setup.
>
> During setup, the driver checks if a FW is already running on the chip
> based on the CTS line, and downloads device specific FW file into the
> chip over UART.
>
> Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx>
> ---
> v2: Removed conf file support and added static data for each chip based on
> compatibility devices mentioned in DT bindings. Handled potential memory
> leaks and null pointer dereference issues, simplified FW download feature,
> handled byte-order and few cosmetic changes. (Ilpo Järvinen, Alok Tiwari,
> Hillf Danton)
> v3: Added conf file support necessary to support different vendor modules,
> moved .h file contents to .c, cosmetic changes. (Luiz Augusto von Dentz,
> Rob Herring, Leon Romanovsky)
> v4: Removed conf file support, optimized driver data, add logic to select
> FW name based on chip signature (Greg KH, Ilpo Jarvinen, Sherry Sun)
> v5: Replaced bt_dev_info() with bt_dev_dbg(), handled user-space cmd
> parsing in nxp_enqueue() in a better way. (Greg KH, Luiz Augusto
> von Dentz)
> ---
> MAINTAINERS | 1 +
> drivers/bluetooth/Kconfig | 11 +
> drivers/bluetooth/Makefile | 1 +
> drivers/bluetooth/btnxpuart.c | 1312 +++++++++++++++++++++++++++++++++
> 4 files changed, 1325 insertions(+)
> create mode 100644 drivers/bluetooth/btnxpuart.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 030ec6fe89df..fdb9b0788c89 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -22840,6 +22840,7 @@ M: Amitkumar Karwar <amitkumar.karwar@xxxxxxx>
> M: Neeraj Kale <neeraj.sanjaykale@xxxxxxx>
> S: Maintained
> F: Documentation/devicetree/bindings/net/bluetooth/nxp,88w8987-bt.yaml
> +F: drivers/bluetooth/btnxpuart.c
>
> THE REST
> M: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
> index 5a1a7bec3c42..359a4833e31f 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 (btnxpuart).
> +
> +
> endmenu
> diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
> index e0b261f24fc9..7a5967e9ac48 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) += btnxpuart.o
>
> obj-$(CONFIG_BT_HCIUART_NOKIA) += hci_nokia.o
>
> diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
> new file mode 100644
> index 000000000000..55f6bf7c5d87
> --- /dev/null
> +++ b/drivers/bluetooth/btnxpuart.c
> @@ -0,0 +1,1312 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * NXP Bluetooth driver
> + * Copyright 2018-2023 NXP
> + */
> +
> +#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 "h4_recv.h"
> +
> +#define MANUFACTURER_NXP 37
> +
> +#define BTNXPUART_TX_STATE_ACTIVE 1
> +#define BTNXPUART_FW_DOWNLOADING 2
> +
> +#define FIRMWARE_W8987 "nxp/uartuart8987_bt.bin"
> +#define FIRMWARE_W8997 "nxp/uartuart8997_bt_v4.bin"
> +#define FIRMWARE_W9098 "nxp/uartuart9098_bt_v1.bin"
> +#define FIRMWARE_IW416 "nxp/uartiw416_bt_v0.bin"
> +#define FIRMWARE_IW612 "nxp/uartspi_n61x_v1.bin.se"
> +
> +#define CHIP_ID_W9098 0x5c03
> +#define CHIP_ID_IW416 0x7201
> +#define CHIP_ID_IW612 0x7601
> +
> +#define HCI_NXP_PRI_BAUDRATE 115200
> +#define HCI_NXP_SEC_BAUDRATE 3000000
> +
> +#define MAX_FW_FILE_NAME_LEN 50
> +
> +/* 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
> +/* 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 vendor command: Independent Reset */
> +#define HCI_NXP_IND_RESET 0xfcfc
> +
> +/* 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
> +
> +/* 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 MAX_USER_PARAMS 10
> +
> +struct ps_data {
> + u8 ps_mode;
> + u8 cur_psmode;
> + u8 ps_state;
> + u8 ps_cmd;
> + u8 h2c_wakeupmode;
> + u8 cur_h2c_wakeupmode;
> + u8 c2h_wakeupmode;
> + u8 c2h_wakeup_gpio;
> + bool driver_sent_cmd;
> + bool timer_on;
> + u32 interval;
> + struct hci_dev *hdev;
> + struct work_struct work;
> + struct timer_list ps_timer;
> +};
> +
> +struct btnxpuart_data {
> + bool fw_dnld_use_high_baudrate;
> + const u8 *fw_name;
> +};
> +
> +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;
> + u8 fw_name[MAX_FW_FILE_NAME_LEN];
> + u32 fw_dnld_v1_offset;
> + u32 fw_v1_sent_bytes;
> + u32 fw_v3_offset_correction;
> + u32 fw_v1_expected_len;
> + wait_queue_head_t suspend_wait_q;
> +
> + u32 new_baudrate;
> + u32 current_baudrate;
> + bool timeout_changed;
> + bool baudrate_changed;
> +
> + struct ps_data *psdata;
> + struct btnxpuart_data *nxp_data;
> +};
> +
> +#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 {
> + __le16 len;
> + __le16 len_comp;
> +} __packed;
> +
> +struct v3_data_req {
> + __le16 len;
> + __le32 offset;
> + __le16 error;
> + u8 crc;
> +} __packed;
> +
> +struct v3_start_ind {
> + __le16 chip_id;
> + u8 loader_ver;
> + u8 crc;
> +} __packed;
> +
> +/* 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 POLYNOMIAL8 0x07
> +#define POLYNOMIAL32 0x04c11db7L
> +
> +struct uart_reg {
> + __le32 address;
> + __le32 value;
> +} __packed;
> +
> +struct uart_config {
> + struct uart_reg clkdiv;
> + struct uart_reg uartdiv;
> + struct uart_reg mcr;
> + struct uart_reg re_init;
> + struct uart_reg icr;
> + struct uart_reg fcr;
> + __le32 crc;
> +} __packed;
> +
> +struct nxp_bootloader_cmd {
> + __le32 header;
> + __le32 arg;
> + __le32 payload_len;
> + __le32 crc;
> +} __packed;
> +
> +static u8 crc8_table[CRC8_TABLE_SIZE];

Shouldn't this be initialized when the module is loaded and not at some
random time later on?

> +static unsigned long crc32_table[256];

Why do you hand-create this, don't we have kernel functions for this?

> +
> +/* Default Power Save configuration */
> +static int h2c_wakeupmode = WAKEUP_METHOD_BREAK;
> +static int ps_mode = PS_MODE_ENABLE;

This will not work.

> +
> +static int init_baudrate = 115200;

and neither will this, as you need to support multiple devices in the
system, your driver should never be only able to work with one device.
Please make these device-specific things, not the same for the whole
driver.

> +static int ps_wakeup(struct btnxpuart_dev *nxpdev)
> +{
> + struct ps_data *psdata = nxpdev->psdata;
> +
> + if (psdata->ps_state == PS_STATE_AWAKE)
> + return 0;
> + psdata->ps_cmd = PS_CMD_EXIT_PS;
> + schedule_work(&psdata->work);
> +
> + return 1;

Why is this function returning anything (and what does 0 and 1 mean?)
when you never actually check the return value of it?

thanks,

greg k-h