[PATCH v5 6/7] Bluetooth: mediatek: Add protocol support for MediaTek serial devices

Sean Wang
2018-07-15T05:53:04Z

On Sat, 2018-07-14 at 18:32 +0200, Marcel Holtmann wrote:
> Hi Sean,
>
> > This adds a driver to run on the top of btuart driver for the MediaTek
> > serial protocol based on running H:4, which can enable the built-in
> > Bluetooth device inside MT7622 SoC.
> >
> > Signed-off-by: Sean Wang <sean.wang@mediatek.com>
> > ---
> > drivers/bluetooth/Kconfig | 11 ++
> > drivers/bluetooth/Makefile | 2 +
> > drivers/bluetooth/btmtkuart.c | 352 ++++++++++++++++++++++++++++++++++++++++++
> > drivers/bluetooth/btmtkuart.h | 116 ++++++++++++++
> > drivers/bluetooth/btuart.c | 18 +++
> > 5 files changed, 499 insertions(+)
> > create mode 100644 drivers/bluetooth/btmtkuart.c
> > create mode 100644 drivers/bluetooth/btmtkuart.h
> >
> > diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
> > index 00fdf5f..4d7d640 100644
> > --- a/drivers/bluetooth/Kconfig
> > +++ b/drivers/bluetooth/Kconfig
> > @@ -85,6 +85,17 @@ config BT_HCIBTUART
> > Say Y here to compile support for Bluetooth UART devices into the
> > kernel or say M to compile it as module (btuart).
> >
> > +config BT_HCIBTUART_MTK
> > + tristate "MediaTek HCI UART driver"
> > + depends on BT_HCIBTUART
> > + help
> > + MediaTek Bluetooth HCI UART driver.
> > + This driver is required if you want to use MediaTek Bluetooth
> > + with serial interface.
> > +
> > + Say Y here to compile support for MediaTek Bluetooth UART devices
> > + into the kernel or say M to compile it as module (btmtkuart).
> > +
> > config BT_HCIUART
> > tristate "HCI UART driver"
> > depends on SERIAL_DEV_BUS || !SERIAL_DEV_BUS
> > diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
> > index 60a19cb..c9a8926 100644
> > --- a/drivers/bluetooth/Makefile
> > +++ b/drivers/bluetooth/Makefile
> > @@ -26,6 +26,8 @@ obj-$(CONFIG_BT_BCM) += btbcm.o
> > obj-$(CONFIG_BT_RTL) += btrtl.o
> > obj-$(CONFIG_BT_QCA) += btqca.o
> >
> > +obj-$(CONFIG_BT_HCIBTUART_MTK) += btmtkuart.o
> > +
> > obj-$(CONFIG_BT_HCIUART_NOKIA) += hci_nokia.o
> >
> > obj-$(CONFIG_BT_HCIRSI) += btrsi.o
> > diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
> > new file mode 100644
> > index 0000000..9eed21c
> > --- /dev/null
> > +++ b/drivers/bluetooth/btmtkuart.c
> > @@ -0,0 +1,352 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// Copyright (c) 2018 MediaTek Inc.
> > +
> > +/*
> > + * Bluetooth support for MediaTek serial devices
> > + *
> > + * Author: Sean Wang <sean.wang@mediatek.com>
> > + *
> > + */
> > +
> > +#include <asm/unaligned.h>
> > +#include <linux/atomic.h>
> > +#include <linux/clk.h>
> > +#include <linux/firmware.h>
> > +#include <linux/module.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/serdev.h>
> > +
> > +#include <net/bluetooth/bluetooth.h>
> > +#include <net/bluetooth/hci_core.h>
> > +
> > +#include "btmtkuart.h"
> > +#include "btuart.h"
> > +#include "h4_recv.h"
> > +
> > +static void mtk_stp_reset(struct mtk_stp_splitter *sp)
> > +{
> > + sp->cursor = 2;
> > + sp->dlen = 0;
> > +}
> > +
> > +static const unsigned char *
> > +mtk_stp_split(struct btuart_dev *bdev, struct mtk_stp_splitter *sp,
> > + const unsigned char *data, int count, int *sz_h4)
> > +{
> > + struct mtk_stp_hdr *shdr;
> > +
> > + /* The cursor is reset when all the data of STP is consumed out. */
> > + if (!sp->dlen && sp->cursor >= 6)
> > + sp->cursor = 0;
> > +
> > + /* Filling pad until all STP info is obtained. */
> > + while (sp->cursor < 6 && count > 0) {
> > + sp->pad[sp->cursor] = *data;
> > + sp->cursor++;
> > + data++;
> > + count--;
> > + }
> > +
> > + /* Retrieve STP info and have a sanity check. */
> > + if (!sp->dlen && sp->cursor >= 6) {
> > + shdr = (struct mtk_stp_hdr *)&sp->pad[2];
> > + sp->dlen = shdr->dlen1 << 8 | shdr->dlen2;
> > +
> > + /* Resync STP when unexpected data is being read. */
> > + if (shdr->prefix != 0x80 || sp->dlen > 2048) {
> > + bt_dev_err(bdev->hdev, "stp format unexpect (%d, %d)",
> > + shdr->prefix, sp->dlen);
> > + mtk_stp_reset(sp);
> > + }
> > + }
> > +
> > + /* Directly quit when there's no data found for H4 can process. */
> > + if (count <= 0)
> > + return NULL;
> > +
> > + /* Tranlate to how much the size of data H4 can handle so far. */
> > + *sz_h4 = min_t(int, count, sp->dlen);
> > + /* Update the remaining size of STP packet. */
> > + sp->dlen -= *sz_h4;
> > +
> > + /* Data points to STP payload which can be handled by H4. */
> > + return data;
> > +}
> > +
> > +static int mtk_stp_send(struct btuart_dev *bdev, struct sk_buff *skb)
> > +{
> > + struct mtk_stp_hdr *shdr;
> > + struct sk_buff *new_skb;
> > + int dlen;
> > +
> > + memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
> > + dlen = skb->len;
> > +
> > + /* Make sure of STP header at least has 4-bytes free space to fill. */
> > + if (unlikely(skb_headroom(skb) < sizeof(*shdr))) {
> > + new_skb = skb_realloc_headroom(skb, sizeof(*shdr));
> > + kfree_skb(skb);
> > + skb = new_skb;
> > + }
> > +
> > + /* Build for STP packet format. */
> > + shdr = skb_push(skb, sizeof(*shdr));
> > + mtk_make_stp_hdr(shdr, 0, dlen);
> > + skb_put_zero(skb, MTK_STP_TLR_SIZE);
> > +
> > + skb_queue_tail(&bdev->txq, skb);
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_hci_wmt_sync(struct hci_dev *hdev, u8 opcode, u8 flag,
> > + u16 plen, const void *param)
> > +{
> > + struct mtk_hci_wmt_cmd wc;
> > + struct mtk_wmt_hdr *hdr;
> > + struct sk_buff *skb;
> > + u32 hlen;
> > +
> > + hlen = sizeof(*hdr) + plen;
> > + if (hlen > 255)
> > + return -EINVAL;
> > +
> > + hdr = (struct mtk_wmt_hdr *)&wc;
> > + mtk_make_wmt_hdr(hdr, opcode, plen, flag);
> > + memcpy(wc.data, param, plen);
> > +
> > + atomic_inc(&hdev->cmd_cnt);
> > +
> > + skb = __hci_cmd_sync_ev(hdev, 0xfc6f, hlen, &wc, HCI_VENDOR_PKT,
> > + HCI_INIT_TIMEOUT);
>
> you have two spaces between = and __hci..

thanks! it'll be fixed in the next version.

> > +
> > + if (IS_ERR(skb)) {
> > + int err = PTR_ERR(skb);
> > +
> > + bt_dev_err(hdev, "Failed to send wmt cmd (%d)\n", err);
>
> No \n here since bt_dev_err already adds it.
>

\n will be removed in the next version

> > + return err;
> > + }
> > +
> > + kfree_skb(skb);
> > +
> > + return 0;
> > +}
> > +
> > +static int mtk_setup_fw(struct hci_dev *hdev)
> > +{
> > + const struct firmware *fw;
> > + const char *fwname;
> > + const u8 *fw_ptr;
> > + size_t fw_size;
> > + int err, dlen;
> > + u8 flag;
> > +
> > + fwname = FIRMWARE_MT7622;
> > +
> > + err = request_firmware(&fw, fwname, &hdev->dev);
> > + if (err < 0) {
> > + bt_dev_err(hdev, "Failed to load firmware file (%d)", err);
> > + return err;
> > + }
> > +
> > + fw_ptr = fw->data;
> > + fw_size = fw->size;
> > +
> > + /* The size of patch header is 30 bytes, should be skip. */
> > + if (fw_size < 30)
> > + return -EINVAL;
> > +
> > + fw_size -= 30;
> > + fw_ptr += 30;
> > +
> > + while (fw_size > 0) {
> > + dlen = min_t(int, 250, fw_size);
> > +
> > + /* Tell deivice the position in sequence. */
> > + flag = (fw_size - dlen <= 0) ? 3 :
> > + (fw_size < fw->size - 30) ? 2 : 1;
>
> Use an if statement here. It is easier to read.
>

thanks, the if statement would be used instead in the next version.

> > +
> > + err = mtk_hci_wmt_sync(hdev, MTK_WMT_PATCH_DWNLD, flag, dlen,
> > + fw_ptr);
> > + if (err < 0)
> > + break;
> > +
> > + fw_size -= dlen;
> > + fw_ptr += dlen;
> > + }
> > +
> > + release_firmware(fw);
> > +
> > + return err;
> > +}
> > +
> > +void *mtk_btuart_init(struct device *dev)
> > +{
> > + struct mtk_bt_dev *soc;
> > +
> > + soc = devm_kzalloc(dev, sizeof(*soc), GFP_KERNEL);
> > + if (!soc)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + soc->sp = devm_kzalloc(dev, sizeof(*soc->sp), GFP_KERNEL);
> > + if (!soc->sp)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + soc->clk = devm_clk_get(dev, "ref");
> > + if (IS_ERR(soc->clk))
> > + return ERR_CAST(soc->clk);
> > +
> > + return soc;
> > +}
> > +EXPORT_SYMBOL_GPL(mtk_btuart_init);
> > +
> > +int mtk_btuart_send(struct hci_dev *hdev, struct sk_buff *skb)
> > +{
> > + struct btuart_dev *bdev = hci_get_drvdata(hdev);
> > +
> > + return mtk_stp_send(bdev, skb);
> > +}
> > +EXPORT_SYMBOL_GPL(mtk_btuart_send);
> > +
> > +int mtk_btuart_hci_frame(struct hci_dev *hdev, struct sk_buff *skb)
> > +{
> > + struct hci_event_hdr *hdr = (void *)skb->data;
> > +
> > + /* Fix up the vendor event id with HCI_VENDOR_PKT instead of
> > + * 0xe4 so that btmon can parse the kind of vendor event properly.
> > + */
> > + if (hdr->evt == 0xe4)
> > + hdr->evt = HCI_VENDOR_PKT;
> > +
> > + /* Each HCI event would go through the core. */
> > + return hci_recv_frame(hdev, skb);
> > +}
> > +EXPORT_SYMBOL_GPL(mtk_btuart_hci_frame);
> > +
> > +int mtk_btuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
> > +{
> > + struct btuart_dev *bdev = hci_get_drvdata(hdev);
> > + const unsigned char *p_left = data, *p_h4;
> > + const struct btuart_vnd *vnd = bdev->vnd;
> > + struct mtk_bt_dev *soc = bdev->data;
> > + int sz_left = count, sz_h4, adv;
> > + int err;
> > +
> > + while (sz_left > 0) {
> > + /* The serial data received from MT7622 BT controller is
> > + * at all time padded around with the STP header and tailer.
> > + *
> > + * A full STP packet is looking like
> > + * -----------------------------------
> > + * | STP header | H:4 | STP tailer |
> > + * -----------------------------------
> > + * but it don't guarantee to contain a full H:4 packet which
> > + * means that it's possible for multiple STP packets forms a
> > + * full H:4 packet and whose length recorded in STP header can
> > + * shows up the most length the H:4 engine can handle in one
> > + * time.
> > + */
> > +
> > + p_h4 = mtk_stp_split(bdev, soc->sp, p_left, sz_left, &sz_h4);
> > + if (!p_h4)
> > + break;
> > +
> > + adv = p_h4 - p_left;
> > + sz_left -= adv;
> > + p_left += adv;
> > +
> > + bdev->rx_skb = h4_recv_buf(bdev->hdev, bdev->rx_skb, p_h4,
> > + sz_h4, vnd->recv_pkts,
> > + vnd->recv_pkts_cnt);
> > + if (IS_ERR(bdev->rx_skb)) {
> > + err = PTR_ERR(bdev->rx_skb);
> > + bt_dev_err(bdev->hdev,
> > + "Frame reassembly failed (%d)", err);
> > + bdev->rx_skb = NULL;
> > + return err;
> > + }
> > +
> > + sz_left -= sz_h4;
> > + p_left += sz_h4;
> > + }
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(mtk_btuart_recv);
> > +
> > +int mtk_btuart_setup(struct hci_dev *hdev)
> > +{
> > + struct btuart_dev *bdev = hci_get_drvdata(hdev);
> > + struct mtk_bt_dev *soc = bdev->data;
> > + struct device *dev;
> > + u8 param = 0x1;
> > + int err = 0;
> > +
> > + dev = &bdev->serdev->dev;
> > +
> > + mtk_stp_reset(soc->sp);
> > +
> > + /* Enable the power domain and clock the device requires. */
> > + pm_runtime_enable(dev);
> > + err = pm_runtime_get_sync(dev);
> > + if (err < 0) {
> > + pm_runtime_put_noidle(dev);
> > + goto err_disable_rpm;
> > + }
> > +
> > + err = clk_prepare_enable(soc->clk);
> > + if (err < 0)
> > + goto err_put_rpm;
> > +
> > + /* Setup a firmware which the device definitely requires. */
> > + err = mtk_setup_fw(hdev);
> > + if (err < 0)
> > + goto err_clk;
> > +
> > + /* Activate funciton the firmware providing to. */
> > + err = mtk_hci_wmt_sync(hdev, MTK_WMT_RST, 0x4, 0, 0);
> > + if (err < 0)
> > + goto err_clk;
> > +
> > + /* Enable Bluetooth protocol. */
> > + err = mtk_hci_wmt_sync(hdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
> > + &param);
> > + if (err < 0)
> > + goto err_clk;
> > +
> > + set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
> > +
> > + return 0;
> > +err_clk:
> > + clk_disable_unprepare(soc->clk);
> > +err_put_rpm:
> > + pm_runtime_put_sync(dev);
> > +err_disable_rpm:
> > + pm_runtime_disable(dev);
> > +
> > + return err;
> > +}
> > +EXPORT_SYMBOL_GPL(mtk_btuart_setup);
> > +
> > +int mtk_btuart_shutdown(struct hci_dev *hdev)
> > +{
> > + struct btuart_dev *bdev = hci_get_drvdata(hdev);
> > + struct device *dev = &bdev->serdev->dev;
> > + struct mtk_bt_dev *soc = bdev->data;
> > + u8 param = 0x0;
> > +
> > + /* Disable the device. */
> > + mtk_hci_wmt_sync(hdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param), &param);
> > +
> > + /* Shutdown the clock and power domain the device requires. */
> > + clk_disable_unprepare(soc->clk);
> > + pm_runtime_put_sync(dev);
> > + pm_runtime_disable(dev);
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(mtk_btuart_shutdown);
> > +
> > +MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
> > +MODULE_DESCRIPTION("Bluetooth Support for MediaTek Serial Devices");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/drivers/bluetooth/btmtkuart.h b/drivers/bluetooth/btmtkuart.h
> > new file mode 100644
> > index 0000000..4c2c24e
> > --- /dev/null
> > +++ b/drivers/bluetooth/btmtkuart.h
> > @@ -0,0 +1,116 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (c) 2018 MediaTek Inc.
> > + *
> > + * Bluetooth support for MediaTek serial devices
> > + *
> > + * Author: Sean Wang <sean.wang@mediatek.com>
> > + *
> > + */
> > +
> > +#define FIRMWARE_MT7622 "mediatek/mt7622pr2h.bin"
> > +
> > +#define MTK_STP_TLR_SIZE 2
> > +
> > +enum {
> > + MTK_WMT_PATCH_DWNLD = 0x1,
> > + MTK_WMT_FUNC_CTRL = 0x6,
> > + MTK_WMT_RST = 0x7
> > +};
> > +
> > +struct mtk_stp_hdr {
> > + u8 prefix;
> > + u8 dlen1:4;
> > + u8 type:4;
> > + u8 dlen2;
> > + u8 cs;
> > +} __packed;
> > +
> > +struct mtk_wmt_hdr {
> > + u8 dir;
> > + u8 op;
> > + __le16 dlen;
> > + u8 flag;
> > +} __packed;
> > +
> > +struct mtk_hci_wmt_cmd {
> > + struct mtk_wmt_hdr hdr;
> > + u8 data[256];
> > +} __packed;
> > +
> > +struct mtk_stp_splitter {
> > + u8 pad[6];
> > + u8 cursor;
> > + u16 dlen;
> > +};
> > +
> > +struct mtk_bt_dev {
> > + struct clk *clk;
> > + struct completion wmt_cmd;
> > + struct mtk_stp_splitter *sp;
> > +};
> > +
> > +static inline void
> > +mtk_make_stp_hdr(struct mtk_stp_hdr *hdr, u8 type, u32 dlen)
> > +{
> > + u8 *p = (u8 *)hdr;
> > +
> > + hdr->prefix = 0x80;
> > + hdr->dlen1 = (dlen & 0xf00) >> 8;
> > + hdr->type = type;
> > + hdr->dlen2 = dlen & 0xff;
> > + hdr->cs = p[0] + p[1] + p[2];
> > +}
> > +
> > +static inline void
> > +mtk_make_wmt_hdr(struct mtk_wmt_hdr *hdr, u8 op, u16 plen, u8 flag)
> > +{
> > + hdr->dir = 1;
> > + hdr->op = op;
> > + hdr->dlen = cpu_to_le16(plen + 1);
> > + hdr->flag = flag;
> > +}
> > +
> > +#if IS_ENABLED(CONFIG_BT_HCIBTUART_MTK)
> > +
> > +void *mtk_btuart_init(struct device *dev);
> > +int mtk_btuart_setup(struct hci_dev *hdev);
> > +int mtk_btuart_shutdown(struct hci_dev *hdev);
> > +int mtk_btuart_send(struct hci_dev *hdev, struct sk_buff *skb);
> > +int mtk_btuart_hci_frame(struct hci_dev *hdev, struct sk_buff *skb);
> > +int mtk_btuart_recv(struct hci_dev *hdev, const u8 *data, size_t count);
> > +
> > +#else
> > +
> > +static void *mtk_btuart_init(struct device *dev)
> > +{
> > + return 0;
> > +}
> > +
> > +static inline int mtk_btuart_setup(struct hci_dev *hdev)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static inline int mtk_btuart_shutdown(struct hci_dev *hdev)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static inline int mtk_btuart_send(struct hci_dev *hdev, struct sk_buff *skb)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static int mtk_btuart_hci_frame(struct hci_dev *hdev, struct sk_buff *skb)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static inline int mtk_btuart_recv(struct hci_dev *hdev, const u8 *data,
> > + size_t count)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +#endif
> > diff --git a/drivers/bluetooth/btuart.c b/drivers/bluetooth/btuart.c
> > index 65d0086..2e715a5 100644
> > --- a/drivers/bluetooth/btuart.c
> > +++ b/drivers/bluetooth/btuart.c
> > @@ -35,6 +35,7 @@
> > #include "h4_recv.h"
> > #include "btuart.h"
> > #include "btbcm.h"
> > +#include "btmtkuart.h"
> >
> > #define VERSION "1.0"
> >
> > @@ -396,6 +397,12 @@ static const struct h4_recv_pkt bcm_recv_pkts[] = {
> > { BCM_RECV_NULL, .recv = hci_recv_diag },
> > };
> >
> > +static const struct h4_recv_pkt mtk_recv_pkts[] = {
> > + { H4_RECV_ACL, .recv = hci_recv_frame },
> > + { H4_RECV_SCO, .recv = hci_recv_frame },
> > + { H4_RECV_EVENT, .recv = mtk_btuart_hci_frame },
> > +};
> > +
> > static const struct btuart_vnd bcm_vnd = {
> > .recv_pkts = bcm_recv_pkts,
> > .recv_pkts_cnt = ARRAY_SIZE(bcm_recv_pkts),
> > @@ -403,6 +410,16 @@ static const struct btuart_vnd bcm_vnd = {
> > .setup = bcm_setup,
> > };
> >
> > +static const struct btuart_vnd mtk_vnd = {
> > + .recv_pkts = mtk_recv_pkts,
> > + .recv_pkts_cnt = ARRAY_SIZE(mtk_recv_pkts),
> > + .init = mtk_btuart_init,
> > + .setup = mtk_btuart_setup,
> > + .shutdown = mtk_btuart_shutdown,
> > + .send = mtk_btuart_send,
> > + .recv = mtk_btuart_recv,
> > +};
> > +
> > static const struct h4_recv_pkt default_recv_pkts[] = {
> > { H4_RECV_ACL, .recv = hci_recv_frame },
> > { H4_RECV_SCO, .recv = hci_recv_frame },
> > @@ -487,6 +504,7 @@ static void btuart_remove(struct serdev_device *serdev)
> > #ifdef CONFIG_OF
> > static const struct of_device_id btuart_of_match_table[] = {
> > { .compatible = "brcm,bcm43438-bt", .data = &bcm_vnd },
> > + { .compatible = "mediatek,mt7622-bluetooth", .data = &mtk_vnd },
> > { }
> > };
> > MODULE_DEVICE_TABLE(of, btuart_of_match_table);
>
> Regards
>
> Marcel
>