TI Bluetooth serdev support

Add serial slave device binding for the TI WiLink series of Bluetooth/FM/GPS devices.

Signed-off-by Rob Herring <[email protected]>

Cc Mark Rutland <[email protected]>

Cc netdev at vger.kernel.org

Cc devicetree at vger.kernel.org

---
v3:
- rebase on bluetooth-next

 .../devicetree/bindings/net/ti,wilink-st.txt       | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/ti,wilink-st.txt

Documentation/devicetree/bindings/net/ti,wilink-st.txt new file +25 -0

new file mode 100644
index 000000000000..cbad73a84ac4
@@ -0,0 +1,35 @@
+TI WiLink 7/8 (wl12xx/wl18xx) Shared Transport BT/FM/GPS devices
+
+TI WiLink devices have a UART interface for providing Bluetooth, FM radio,
+and GPS over what's called "shared transport". The shared transport is
+standard BT HCI protocol with additional channels for the other functions.
+
+These devices also have a separate WiFi interface as described in
+wireless/ti,wlcore.txt.
+
+This bindings follows the UART slave device binding in
+../serial/slave-device.txt.
+
+Required properties:
+ - compatible: should be one of the following:
+    "ti,wl1271-st"
+    "ti,wl1273-st"
+    "ti,wl1831-st"
+    "ti,wl1835-st"
+    "ti,wl1837-st"
+
+Optional properties:
+ - enable-gpios : GPIO signal controlling enabling of BT. Active high.
+ - vio-supply : Vio input supply (1.8V)
+ - vbat-supply : Vbat input supply (2.9-4.8V)
+

On Apr 13, 2017 10:04 AM, "Rob Herring" <[email protected]> wrote:

Add serial slave device binding for the TI WiLink series of Bluetooth/FM/GPS devices.

Signed-off-by Rob Herring <[email protected]>

Cc Mark Rutland <[email protected]>

Cc netdev at vger.kernel.org

Cc devicetree at vger.kernel.org

---
v3:
- rebase on bluetooth-next

 .../devicetree/bindings/net/ti,wilink-st.txt       | 35
++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/ti,wilink-st.txt

Documentation/devicetree/bindings/net/ti,wilink-st.txt new file +20 -0

new file mode 100644
index 000000000000..cbad73a84ac4
@@ -0,0 +1,35 @@
+TI WiLink 7/8 (wl12xx/wl18xx) Shared Transport BT/FM/GPS devices
+
+TI WiLink devices have a UART interface for providing Bluetooth, FM radio,
+and GPS over what's called "shared transport". The shared transport is
+standard BT HCI protocol with additional channels for the other functions.
+
+These devices also have a separate WiFi interface as described in
+wireless/ti,wlcore.txt.
+
+This bindings follows the UART slave device binding in
+../serial/slave-device.txt.
+
+Required properties:
+ - compatible: should be one of the following:
+    "ti,wl1271-st"
+    "ti,wl1273-st"
+    "ti,wl1831-st"
+    "ti,wl1835-st"
+    "ti,wl1837-st"
+

Would you expect the wl1283 chipset too?

I can help test this if you like after the holiday weekend. I have a board with WL1283 and currently using pdata-quirks to support it.

drivers/bluetooth/hci_ll.c +9 -0

+	}
+	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;

Avoid NULL pointer dereference occurring due to freeing skb containing an error pointer. It can easily be triggered by using the driver with broken uart (i.e. due to misconfigured pinmuxing).

Fixes 371805522f87 ("bluetooth: hci_uart: add LL protocol serdev driver support")

Signed-off-by Sebastian Reichel <[email protected]>

---
drivers/bluetooth/hci_ll.c | 3 +--

1 file changed, 1 insertion(+), 2 deletions(-)

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.

Signed-off-by Rob Herring <[email protected]>

Cc Marcel Holtmann <[email protected]>

Cc Gustavo Padovan <[email protected]>

Cc Johan Hedberg <[email protected]>

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(-)

drivers/bluetooth/hci_ll.c +261 -2

index 02692fe30279..485e8eb04542 100644
@@ -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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Quoted 10 lines · Rob Herring

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?

Quoted 5 lines

drivers/bluetooth/hci_ll.c +5 -0

+static int hci_ti_probe(struct serdev_device *serdev)
+{
+       struct hci_uart *hu;
+       struct ll_device *lldev;
+       u32 max_speed = 3000000;

Quoted 2 lines

drivers/bluetooth/hci_ll.c +2 -0

+       of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
+       hci_uart_set_speeds(hu, 115200, max_speed);

This series adds serdev support to the HCI LL protocol used on TI BT modules and enables support on HiKey board with with the WL1835 module. With this the custom TI UIM daemon and btattach are no longer needed.

The series is available on this git branch[1]. This version is rebased on bluetooth-next tree containing its dependencies.

Rob

[1] git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git ti-bluetooth

Rob Herring (4):
dt-bindings: net: Add TI WiLink shared transport binding
bluetooth: hci_uart: remove unused hci_uart_init_tty
bluetooth: hci_uart: add LL protocol serdev driver support
arm64: dts: hikey: add WL1835 Bluetooth device node

.../devicetree/bindings/net/ti,wilink-st.txt       |  35 +++
arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts     |   5 +
drivers/bluetooth/hci_ldisc.c                      |  19 --
drivers/bluetooth/hci_ll.c                         | 262 ++++++++++++++++++++-
drivers/bluetooth/hci_uart.h                       |   1 -
5 files changed, 301 insertions(+), 21 deletions(-)

create mode 100644 Documentation/devicetree/bindings/net/ti,wilink-st.txt