[PATCH v3 3/4] bluetooth: hci_uart: add LL protocol serdev driver support
Adam Ford
aford173 at gmail.com
Mon Apr 17 16:11:52 EDT 2017
On Thu, Apr 13, 2017 at 10:03 AM, Rob Herring <robh at kernel.org> wrote:
> Turns out that the LL protocol and the TI-ST are the same thing AFAICT.
> The TI-ST adds firmware loading, GPIO control, and shared access for
> NFC, FM radio, etc. For now, we're only implementing what is needed for
> BT. This mirrors other drivers like BCM and Intel, but uses the new
> serdev bus.
>
> The firmware loading is greatly simplified by using existing
> infrastructure to send commands. It may be a bit slower than the
> original code using synchronous functions, but the real bottleneck is
> likely doing firmware load at 115.2kbps.
I am using pdata-quirks to drive my wl1283 Bluetooth on a DM3730. I
have the Bluetooth set to 3000000 baud in pdata quirks. Looking at
the binding, I don't see an option to set the baudrate. Is there (or
will there) be a way to set the baud rate of the Bluetooth?
adam
>
> Signed-off-by: Rob Herring <robh at kernel.org>
> Cc: Marcel Holtmann <marcel at holtmann.org>
> Cc: Gustavo Padovan <gustavo at padovan.org>
> Cc: Johan Hedberg <johan.hedberg at gmail.com>
> Cc: linux-bluetooth at vger.kernel.org
> ---
> v3:
> - rebase on bluetooth-next
> - Add explicit of.h include
> v2:
> - Use IS_ENABLED() to fix module build
>
> drivers/bluetooth/hci_ll.c | 262 ++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 261 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
> index 02692fe30279..485e8eb04542 100644
> --- a/drivers/bluetooth/hci_ll.c
> +++ b/drivers/bluetooth/hci_ll.c
> @@ -34,20 +34,24 @@
> #include <linux/sched.h>
> #include <linux/types.h>
> #include <linux/fcntl.h>
> +#include <linux/firmware.h>
> #include <linux/interrupt.h>
> #include <linux/ptrace.h>
> #include <linux/poll.h>
>
> #include <linux/slab.h>
> -#include <linux/tty.h>
> #include <linux/errno.h>
> #include <linux/string.h>
> #include <linux/signal.h>
> #include <linux/ioctl.h>
> +#include <linux/of.h>
> +#include <linux/serdev.h>
> #include <linux/skbuff.h>
> +#include <linux/ti_wilink_st.h>
>
> #include <net/bluetooth/bluetooth.h>
> #include <net/bluetooth/hci_core.h>
> +#include <linux/gpio/consumer.h>
>
> #include "hci_uart.h"
>
> @@ -76,6 +80,12 @@ struct hcill_cmd {
> u8 cmd;
> } __packed;
>
> +struct ll_device {
> + struct hci_uart hu;
> + struct serdev_device *serdev;
> + struct gpio_desc *enable_gpio;
> +};
> +
> struct ll_struct {
> unsigned long rx_state;
> unsigned long rx_count;
> @@ -136,6 +146,9 @@ static int ll_open(struct hci_uart *hu)
>
> hu->priv = ll;
>
> + if (hu->serdev)
> + serdev_device_open(hu->serdev);
> +
> return 0;
> }
>
> @@ -164,6 +177,13 @@ static int ll_close(struct hci_uart *hu)
>
> kfree_skb(ll->rx_skb);
>
> + if (hu->serdev) {
> + struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
> + gpiod_set_value_cansleep(lldev->enable_gpio, 0);
> +
> + serdev_device_close(hu->serdev);
> + }
> +
> hu->priv = NULL;
>
> kfree(ll);
> @@ -505,9 +525,245 @@ static struct sk_buff *ll_dequeue(struct hci_uart *hu)
> return skb_dequeue(&ll->txq);
> }
>
> +#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
> +static int read_local_version(struct hci_dev *hdev)
> +{
> + int err = 0;
> + unsigned short version = 0;
> + struct sk_buff *skb;
> + struct hci_rp_read_local_version *ver;
> +
> + skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL, HCI_INIT_TIMEOUT);
> + if (IS_ERR(skb)) {
> + bt_dev_err(hdev, "Reading TI version information failed (%ld)",
> + PTR_ERR(skb));
> + err = PTR_ERR(skb);
> + goto out;
> + }
> + if (skb->len != sizeof(*ver)) {
> + err = -EILSEQ;
> + goto out;
> + }
> +
> + ver = (struct hci_rp_read_local_version *)skb->data;
> + if (le16_to_cpu(ver->manufacturer) != 13) {
> + err = -ENODEV;
> + goto out;
> + }
> +
> + version = le16_to_cpu(ver->lmp_subver);
> +
> +out:
> + if (err) bt_dev_err(hdev, "Failed to read TI version info: %d", err);
> + kfree_skb(skb);
> + return err ? err : version;
> +}
> +
> +/**
> + * download_firmware -
> + * internal function which parses through the .bts firmware
> + * script file intreprets SEND, DELAY actions only as of now
> + */
> +static int download_firmware(struct ll_device *lldev)
> +{
> + unsigned short chip, min_ver, maj_ver;
> + int version, err, len;
> + unsigned char *ptr, *action_ptr;
> + unsigned char bts_scr_name[40]; /* 40 char long bts scr name? */
> + const struct firmware *fw;
> + struct sk_buff *skb;
> + struct hci_command *cmd;
> +
> + version = read_local_version(lldev->hu.hdev);
> + if (version < 0)
> + return version;
> +
> + chip = (version & 0x7C00) >> 10;
> + min_ver = (version & 0x007F);
> + maj_ver = (version & 0x0380) >> 7;
> + if (version & 0x8000)
> + maj_ver |= 0x0008;
> +
> + snprintf(bts_scr_name, sizeof(bts_scr_name),
> + "ti-connectivity/TIInit_%d.%d.%d.bts",
> + chip, maj_ver, min_ver);
> +
> + err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
> + if (err || !fw->data || !fw->size) {
> + bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
> + err, bts_scr_name);
> + return -EINVAL;
> + }
> + ptr = (void *)fw->data;
> + len = fw->size;
> + /* bts_header to remove out magic number and
> + * version
> + */
> + ptr += sizeof(struct bts_header);
> + len -= sizeof(struct bts_header);
> +
> + while (len > 0 && ptr) {
> + bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
> + ((struct bts_action *)ptr)->size,
> + ((struct bts_action *)ptr)->type);
> +
> + action_ptr = &(((struct bts_action *)ptr)->data[0]);
> +
> + switch (((struct bts_action *)ptr)->type) {
> + case ACTION_SEND_COMMAND: /* action send */
> + bt_dev_dbg(lldev->hu.hdev, "S");
> + cmd = (struct hci_command *)action_ptr;
> + if (cmd->opcode == 0xff36) {
> + /* ignore remote change
> + * baud rate HCI VS command */
> + bt_dev_warn(lldev->hu.hdev, "change remote baud rate command in firmware");
> + break;
> + }
> + if (cmd->prefix != 1)
> + bt_dev_dbg(lldev->hu.hdev, "command type %d\n", cmd->prefix);
> +
> + skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen, &cmd->speed, HCI_INIT_TIMEOUT);
> + if (IS_ERR(skb)) {
> + bt_dev_err(lldev->hu.hdev, "send command failed\n");
> + goto out_rel_fw;
> + }
> + kfree_skb(skb);
> + break;
> + case ACTION_WAIT_EVENT: /* wait */
> + /* no need to wait as command was synchronous */
> + bt_dev_dbg(lldev->hu.hdev, "W");
> + break;
> + case ACTION_DELAY: /* sleep */
> + bt_dev_info(lldev->hu.hdev, "sleep command in scr");
> + mdelay(((struct bts_action_delay *)action_ptr)->msec);
> + break;
> + }
> + len -= (sizeof(struct bts_action) +
> + ((struct bts_action *)ptr)->size);
> + ptr += sizeof(struct bts_action) +
> + ((struct bts_action *)ptr)->size;
> + }
> +
> +out_rel_fw:
> + /* fw download complete */
> + release_firmware(fw);
> + return err;
> +}
> +
> +static int ll_setup(struct hci_uart *hu)
> +{
> + int err, retry = 3;
> + struct ll_device *lldev;
> + struct serdev_device *serdev = hu->serdev;
> + u32 speed;
> +
> + if (!serdev)
> + return 0;
> +
> + lldev = serdev_device_get_drvdata(serdev);
> +
> + serdev_device_set_flow_control(serdev, true);
> +
> + do {
> + /* Configure BT_EN to HIGH state */
> + gpiod_set_value_cansleep(lldev->enable_gpio, 0);
> + msleep(5);
> + gpiod_set_value_cansleep(lldev->enable_gpio, 1);
> + msleep(100);
> +
> + err = download_firmware(lldev);
> + if (!err)
> + break;
> +
> + /* Toggle BT_EN and retry */
> + bt_dev_err(hu->hdev, "download firmware failed, retrying...");
> + } while (retry--);
> +
> + if (err)
> + return err;
> +
> + /* Operational speed if any */
> + if (hu->oper_speed)
> + speed = hu->oper_speed;
> + else if (hu->proto->oper_speed)
> + speed = hu->proto->oper_speed;
> + else
> + speed = 0;
> +
> + if (speed) {
> + struct sk_buff *skb = __hci_cmd_sync(hu->hdev, 0xff36, sizeof(speed), &speed, HCI_INIT_TIMEOUT);
> + if (!IS_ERR(skb)) {
> + kfree_skb(skb);
> + serdev_device_set_baudrate(serdev, speed);
> + }
> + }
> +
> + return 0;
> +}
> +
> +static const struct hci_uart_proto llp;
> +
> +static int hci_ti_probe(struct serdev_device *serdev)
> +{
> + struct hci_uart *hu;
> + struct ll_device *lldev;
> + u32 max_speed = 3000000;
> +
> + lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
> + if (!lldev)
> + return -ENOMEM;
> + hu = &lldev->hu;
> +
> + serdev_device_set_drvdata(serdev, lldev);
> + lldev->serdev = hu->serdev = serdev;
> +
> + lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev, "enable", GPIOD_OUT_LOW);
> + if (IS_ERR(lldev->enable_gpio))
> + return PTR_ERR(lldev->enable_gpio);
> +
> + of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
> + hci_uart_set_speeds(hu, 115200, max_speed);
> +
> + return hci_uart_register_device(hu, &llp);
> +}
> +
> +static void hci_ti_remove(struct serdev_device *serdev)
> +{
> + struct ll_device *lldev = serdev_device_get_drvdata(serdev);
> + struct hci_uart *hu = &lldev->hu;
> + struct hci_dev *hdev = hu->hdev;
> +
> + cancel_work_sync(&hu->write_work);
> +
> + hci_unregister_dev(hdev);
> + hci_free_dev(hdev);
> + hu->proto->close(hu);
> +}
> +
> +static const struct of_device_id hci_ti_of_match[] = {
> + { .compatible = "ti,wl1831-st" },
> + { .compatible = "ti,wl1835-st" },
> + { .compatible = "ti,wl1837-st" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, hci_ti_of_match);
> +
> +static struct serdev_device_driver hci_ti_drv = {
> + .driver = {
> + .name = "hci-ti",
> + .of_match_table = of_match_ptr(hci_ti_of_match),
> + },
> + .probe = hci_ti_probe,
> + .remove = hci_ti_remove,
> +};
> +#else
> +#define ll_setup NULL
> +#endif
> +
> static const struct hci_uart_proto llp = {
> .id = HCI_UART_LL,
> .name = "LL",
> + .setup = ll_setup,
> .open = ll_open,
> .close = ll_close,
> .recv = ll_recv,
> @@ -518,10 +774,14 @@ static const struct hci_uart_proto llp = {
>
> int __init ll_init(void)
> {
> + serdev_device_driver_register(&hci_ti_drv);
> +
> return hci_uart_register_proto(&llp);
> }
>
> int __exit ll_deinit(void)
> {
> + serdev_device_driver_unregister(&hci_ti_drv);
> +
> return hci_uart_unregister_proto(&llp);
> }
> --
> 2.11.0
>
>
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