diff mbox series

[v14,1/4] usb: Add support for Intel LJCA device

Message ID 1693806261-12958-2-git-send-email-wentong.wu@intel.com (mailing list archive)
State Superseded
Headers show
Series Add Intel LJCA device driver | expand

Commit Message

Wu, Wentong Sept. 4, 2023, 5:44 a.m. UTC
Implements the USB part of Intel USB-I2C/GPIO/SPI adapter device
named "La Jolla Cove Adapter" (LJCA).

The communication between the various LJCA module drivers and the
hardware will be muxed/demuxed by this driver. Three modules (
I2C, GPIO, and SPI) are supported currently.

Each sub-module of LJCA device is identified by type field within
the LJCA message header.

The sub-modules of LJCA can use ljca_transfer() to issue a transfer
between host and hardware. And ljca_register_event_cb is exported
to LJCA sub-module drivers for hardware event subscription.

The minimum code in ASL that covers this board is
Scope (\_SB.PCI0.DWC3.RHUB.HS01)
    {
        Device (GPIO)
        {
            Name (_ADR, Zero)
            Name (_STA, 0x0F)
        }

        Device (I2C)
        {
            Name (_ADR, One)
            Name (_STA, 0x0F)
        }

        Device (SPI)
        {
            Name (_ADR, 0x02)
            Name (_STA, 0x0F)
        }
    }

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/usb/misc/Kconfig    |  14 +
 drivers/usb/misc/Makefile   |   1 +
 drivers/usb/misc/usb-ljca.c | 834 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/usb/ljca.h    | 113 ++++++
 4 files changed, 962 insertions(+)
 create mode 100644 drivers/usb/misc/usb-ljca.c
 create mode 100644 include/linux/usb/ljca.h

Comments

Hans de Goede Sept. 4, 2023, 7:45 a.m. UTC | #1
Hi,

On 9/4/23 07:44, Wentong Wu wrote:
> Implements the USB part of Intel USB-I2C/GPIO/SPI adapter device
> named "La Jolla Cove Adapter" (LJCA).
> 
> The communication between the various LJCA module drivers and the
> hardware will be muxed/demuxed by this driver. Three modules (
> I2C, GPIO, and SPI) are supported currently.
> 
> Each sub-module of LJCA device is identified by type field within
> the LJCA message header.
> 
> The sub-modules of LJCA can use ljca_transfer() to issue a transfer
> between host and hardware. And ljca_register_event_cb is exported
> to LJCA sub-module drivers for hardware event subscription.
> 
> The minimum code in ASL that covers this board is
> Scope (\_SB.PCI0.DWC3.RHUB.HS01)
>     {
>         Device (GPIO)
>         {
>             Name (_ADR, Zero)
>             Name (_STA, 0x0F)
>         }
> 
>         Device (I2C)
>         {
>             Name (_ADR, One)
>             Name (_STA, 0x0F)
>         }
> 
>         Device (SPI)
>         {
>             Name (_ADR, 0x02)
>             Name (_STA, 0x0F)
>         }
>     }
> 
> Signed-off-by: Wentong Wu <wentong.wu@intel.com>
> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
> Tested-by: Hans de Goede <hdegoede@redhat.com>
> ---

<snip>

> +#ifdef CONFIG_ACPI
> +struct ljca_match_ids_walk_data {
> +	const struct acpi_device_id *ids;
> +	const char *uid;
> +	struct acpi_device *adev;
> +};
> +
> +static const struct acpi_device_id ljca_gpio_hids[] = {
> +	{ "INTC1074" },
> +	{ "INTC1096" },
> +	{ "INTC100B" },
> +	{ "INTC10D1" },
> +	{},
> +};
> +
> +static const struct acpi_device_id ljca_i2c_hids[] = {
> +	{ "INTC1075" },
> +	{ "INTC1097" },
> +	{ "INTC100C" },
> +	{ "INTC10D2" },
> +	{},
> +};
> +
> +static const struct acpi_device_id ljca_spi_hids[] = {
> +	{ "INTC1091" },
> +	{ "INTC1098" },
> +	{ "INTC100D" },
> +	{ "INTC10D3" },
> +	{},
> +};
> +
> +static int ljca_match_device_ids(struct acpi_device *adev, void *data)
> +{
> +	struct ljca_match_ids_walk_data *wd = data;
> +	const char *uid = acpi_device_uid(adev);
> +
> +	if (acpi_match_device_ids(adev, wd->ids))
> +		return 0;
> +
> +	if (!wd->uid)
> +		goto match;
> +
> +	if (!uid)
> +		uid = "0";
> +	else
> +		uid = memchr(uid, wd->uid[0], strlen(uid));

Note this line can be simplified to:

		uid = strchr(uid, wd->uid[0]);

Regards,

Hans
Wu, Wentong Sept. 4, 2023, 7:52 a.m. UTC | #2
> From: Hans de Goede <hdegoede@redhat.com>
> 
> Hi,
> 
> On 9/4/23 07:44, Wentong Wu wrote:
> > Implements the USB part of Intel USB-I2C/GPIO/SPI adapter device named
> > "La Jolla Cove Adapter" (LJCA).
> >
> > The communication between the various LJCA module drivers and the
> > hardware will be muxed/demuxed by this driver. Three modules ( I2C,
> > GPIO, and SPI) are supported currently.
> >
> > Each sub-module of LJCA device is identified by type field within the
> > LJCA message header.
> >
> > The sub-modules of LJCA can use ljca_transfer() to issue a transfer
> > between host and hardware. And ljca_register_event_cb is exported to
> > LJCA sub-module drivers for hardware event subscription.
> >
> > The minimum code in ASL that covers this board is Scope
> > (\_SB.PCI0.DWC3.RHUB.HS01)
> >     {
> >         Device (GPIO)
> >         {
> >             Name (_ADR, Zero)
> >             Name (_STA, 0x0F)
> >         }
> >
> >         Device (I2C)
> >         {
> >             Name (_ADR, One)
> >             Name (_STA, 0x0F)
> >         }
> >
> >         Device (SPI)
> >         {
> >             Name (_ADR, 0x02)
> >             Name (_STA, 0x0F)
> >         }
> >     }
> >
> > Signed-off-by: Wentong Wu <wentong.wu@intel.com>
> > Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
> > Tested-by: Hans de Goede <hdegoede@redhat.com>
> > ---
> > +
> > +static int ljca_match_device_ids(struct acpi_device *adev, void
> > +*data) {
> > +	struct ljca_match_ids_walk_data *wd = data;
> > +	const char *uid = acpi_device_uid(adev);
> > +
> > +	if (acpi_match_device_ids(adev, wd->ids))
> > +		return 0;
> > +
> > +	if (!wd->uid)
> > +		goto match;
> > +
> > +	if (!uid)
> > +		uid = "0";
> > +	else
> > +		uid = memchr(uid, wd->uid[0], strlen(uid));
> 
> Note this line can be simplified to:
> 
> 		uid = strchr(uid, wd->uid[0]);

Ack, this will be included in next version, thanks.

BR,
Wentong 
> 
> Regards,
> 
> Hans
Oliver Neukum Sept. 4, 2023, 10:33 a.m. UTC | #3
On 04.09.23 07:44, Wentong Wu wrote:

> +static int ljca_send(struct ljca_adapter *adap, u8 type, u8 cmd,
> +		     const void *obuf, unsigned int obuf_len, void *ibuf,
> +		     unsigned int ibuf_len, bool ack, unsigned long timeout)
> +{
> +	unsigned int msg_len = sizeof(struct ljca_msg) + obuf_len;
> +	struct ljca_msg *header = adap->tx_buf;
> +	unsigned long flags;
> +	unsigned int actual;
> +	int ret = 0;
> +
> +	if (msg_len > adap->tx_buf_len)
> +		return -EINVAL;
> +
> +	mutex_lock(&adap->mutex);
> +
> +	spin_lock_irqsave(&adap->lock, flags);
> +
> +	header->type = type;
> +	header->cmd = cmd;
> +	header->len = obuf_len;
> +	if (obuf)
> +		memcpy(header->data, obuf, obuf_len);
> +
> +	header->flags = LJCA_CMPL_FLAG | (ack ? LJCA_ACK_FLAG : 0);
> +
> +	adap->ex_buf = ibuf;
> +	adap->ex_buf_len = ibuf_len;
> +	adap->actual_length = 0;
> +
> +	spin_unlock_irqrestore(&adap->lock, flags);
> +
> +	reinit_completion(&adap->cmd_completion);
> +
> +	usb_autopm_get_interface(adap->intf);
> +
> +	ret = usb_bulk_msg(adap->usb_dev, adap->tx_pipe, header,
> +			   msg_len, &actual, LJCA_WRITE_TIMEOUT_MS);
> +	if (!ret && ack) {
> +		ret = wait_for_completion_timeout(&adap->cmd_completion,
> +						  timeout);

Let's suppose we are here, when a device is unplugged.
timeout is arbitrary as it is passed down to us.

> +		if (ret < 0) {
> +			goto out;
> +		} if (!ret) {
> +			ret = -ETIMEDOUT;
> +			goto out;
> +		}
> +	}
> +	ret = adap->actual_length;
> +
> +out:
> +	spin_lock_irqsave(&adap->lock, flags);
> +	adap->ex_buf = NULL;
> +	adap->ex_buf_len = 0;
> +
> +	memset(header, 0, sizeof(*header));
> +	spin_unlock_irqrestore(&adap->lock, flags);
> +
> +	usb_autopm_put_interface(adap->intf);
> +
> +	mutex_unlock(&adap->mutex);
> +
> +	return ret;
> +}
> +

[..]

> +static void ljca_disconnect(struct usb_interface *interface)
> +{
> +	struct ljca_adapter *adap = usb_get_intfdata(interface);
> +	struct ljca_client *client, *next;
> +
> +	usb_kill_urb(adap->rx_urb);
> +
> +	list_for_each_entry_safe(client, next, &adap->client_list, link) {
> +		auxiliary_device_delete(&client->auxdev);
> +		auxiliary_device_uninit(&client->auxdev);
> +
> +		list_del_init(&client->link);
> +		kfree(client);
> +	}
> +
> +	usb_free_urb(adap->rx_urb);
> +
> +	usb_put_intf(adap->intf);
> +
> +	mutex_destroy(&adap->mutex);
> +}

And we execute this. rx_urb is killed and does nothing.
I see nothing that terminates the waiting if you hit the wrong window.
It seems like this needs to complete the waiting.

	Regards
		Oliver
Wu, Wentong Sept. 4, 2023, 1:52 p.m. UTC | #4
> From: Oliver Neukum <oneukum@suse.com>
> 
> On 04.09.23 07:44, Wentong Wu wrote:
> 
> > +static int ljca_send(struct ljca_adapter *adap, u8 type, u8 cmd,
> > +		     const void *obuf, unsigned int obuf_len, void *ibuf,
> > +		     unsigned int ibuf_len, bool ack, unsigned long timeout) {
> > +	unsigned int msg_len = sizeof(struct ljca_msg) + obuf_len;
> > +	struct ljca_msg *header = adap->tx_buf;
> > +	unsigned long flags;
> > +	unsigned int actual;
> > +	int ret = 0;
> > +
> > +	if (msg_len > adap->tx_buf_len)
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&adap->mutex);
> > +
> > +	spin_lock_irqsave(&adap->lock, flags);
> > +
> > +	header->type = type;
> > +	header->cmd = cmd;
> > +	header->len = obuf_len;
> > +	if (obuf)
> > +		memcpy(header->data, obuf, obuf_len);
> > +
> > +	header->flags = LJCA_CMPL_FLAG | (ack ? LJCA_ACK_FLAG : 0);
> > +
> > +	adap->ex_buf = ibuf;
> > +	adap->ex_buf_len = ibuf_len;
> > +	adap->actual_length = 0;
> > +
> > +	spin_unlock_irqrestore(&adap->lock, flags);
> > +
> > +	reinit_completion(&adap->cmd_completion);
> > +
> > +	usb_autopm_get_interface(adap->intf);
> > +
> > +	ret = usb_bulk_msg(adap->usb_dev, adap->tx_pipe, header,
> > +			   msg_len, &actual, LJCA_WRITE_TIMEOUT_MS);
> > +	if (!ret && ack) {
> > +		ret = wait_for_completion_timeout(&adap->cmd_completion,
> > +						  timeout);
> 
> Let's suppose we are here, when a device is unplugged.
> timeout is arbitrary as it is passed down to us.
> 
> > +		if (ret < 0) {
> > +			goto out;
> > +		} if (!ret) {
> > +			ret = -ETIMEDOUT;
> > +			goto out;
> > +		}
> > +	}
> > +	ret = adap->actual_length;
> > +
> > +out:
> > +	spin_lock_irqsave(&adap->lock, flags);
> > +	adap->ex_buf = NULL;
> > +	adap->ex_buf_len = 0;
> > +
> > +	memset(header, 0, sizeof(*header));
> > +	spin_unlock_irqrestore(&adap->lock, flags);
> > +
> > +	usb_autopm_put_interface(adap->intf);
> > +
> > +	mutex_unlock(&adap->mutex);
> > +
> > +	return ret;
> > +}
> > +
> 
> [..]
> 
> > +static void ljca_disconnect(struct usb_interface *interface) {
> > +	struct ljca_adapter *adap = usb_get_intfdata(interface);
> > +	struct ljca_client *client, *next;
> > +
> > +	usb_kill_urb(adap->rx_urb);
> > +
> > +	list_for_each_entry_safe(client, next, &adap->client_list, link) {
> > +		auxiliary_device_delete(&client->auxdev);
> > +		auxiliary_device_uninit(&client->auxdev);
> > +
> > +		list_del_init(&client->link);
> > +		kfree(client);
> > +	}
> > +
> > +	usb_free_urb(adap->rx_urb);
> > +
> > +	usb_put_intf(adap->intf);
> > +
> > +	mutex_destroy(&adap->mutex);
> > +}
> 
> And we execute this. rx_urb is killed and does nothing.
> I see nothing that terminates the waiting if you hit the wrong window.

I think the auxiliary_device_delete will trigger the remove function of ljca
client in his own sub system, and the delete() or remove() of every subsystem
will not return until the ongoing transfer(probably blocked by above
cmd_completion) complete. And that also makes sure no more transfers
comes to there.

BR,
Wentong
> It seems like this needs to complete the waiting.
> 
> 	Regards
> 		Oliver
Oliver Neukum Sept. 4, 2023, 2:06 p.m. UTC | #5
On 04.09.23 15:52, Wu, Wentong wrote:
>> From: Oliver Neukum <oneukum@suse.com>

>> And we execute this. rx_urb is killed and does nothing.
>> I see nothing that terminates the waiting if you hit the wrong window.
> 
> I think the auxiliary_device_delete will trigger the remove function of ljca
> client in his own sub system, and the delete() or remove() of every subsystem
> will not return until the ongoing transfer(probably blocked by above
> cmd_completion) complete. And that also makes sure no more transfers
> comes to there.

Sure, you will not free used memory. But what allows you to be sure that you
make any progress at all? That is that you will hang arbitrarily long in
disconnect?

	Regards
		Oliver
Wu, Wentong Sept. 5, 2023, 2:20 a.m. UTC | #6
Hi Oliver,

Thanks for your review

> From: Oliver Neukum <oneukum@suse.com>
> On 04.09.23 15:52, Wu, Wentong wrote:
> >> From: Oliver Neukum <oneukum@suse.com>
> 
> >> And we execute this. rx_urb is killed and does nothing.
> >> I see nothing that terminates the waiting if you hit the wrong window.
> >
> > I think the auxiliary_device_delete will trigger the remove function
> > of ljca client in his own sub system, and the delete() or remove() of
> > every subsystem will not return until the ongoing transfer(probably
> > blocked by above
> > cmd_completion) complete. And that also makes sure no more transfers
> > comes to there.
> 
> Sure, you will not free used memory. But what allows you to be sure that you make any progress at all? 
>
> That is that you will hang arbitrarily long in disconnect?
This routine isn't called in an interrupt context, and it allows sleep or wait
something before the real shutdown like many drivers' remove() or
disconnect() do.

If we want to speed up the disconnect(), below changes is to complete the
cmd_completion if usb_kill_urb() has been called, but there is still possibility
ljca client init one more transfer before auxiliary_device_delete()

@@ -206,7 +206,11 @@ static void ljca_recv(struct urb *urb)
 
        if (urb->status) {
                /* sync/async unlink faults aren't errors */
-               if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
+               if (urb->status == -ENOENT) {
+                       complete(&adap->cmd_completion);
+                       return;
+               }
+               if (urb->status == -ECONNRESET ||
                    urb->status == -ESHUTDOWN)
                        return;

perhaps we could add one more 'status' field in ljca_adapter to represent
disconnect() happen or not, and it will be checked in the beginning of
ljca_send() to avoid any new transfer.

BR,
Wentong

> 
> 	Regards
> 		Oliver
Oliver Neukum Sept. 5, 2023, 8:46 a.m. UTC | #7
On 05.09.23 04:20, Wu, Wentong wrote:

Hi,

>> That is that you will hang arbitrarily long in disconnect?
> This routine isn't called in an interrupt context, and it allows sleep or wait
> something before the real shutdown like many drivers' remove() or
> disconnect() do.

It is, however, in the context of a kernel thread. We can wait, but not for
arbitrary periods.

> If we want to speed up the disconnect(), below changes is to complete the
> cmd_completion if usb_kill_urb() has been called, but there is still possibility
> ljca client init one more transfer before auxiliary_device_delete()
> 
> @@ -206,7 +206,11 @@ static void ljca_recv(struct urb *urb)
>   
>          if (urb->status) {
>                  /* sync/async unlink faults aren't errors */
> -               if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
> +               if (urb->status == -ENOENT) {
> +                       complete(&adap->cmd_completion);
> +                       return;

I'd say you'd break suspend() by such a change.
You cannot complete in the interrupt handler, unless you can determine
why the URB is killed.
  
> +               }
> +               if (urb->status == -ECONNRESET ||
>                      urb->status == -ESHUTDOWN)
>                          return;
> 
> perhaps we could add one more 'status' field in ljca_adapter to represent
> disconnect() happen or not, and it will be checked in the beginning of
> ljca_send() to avoid any new transfer.

That would be a solution.


	Regards
		Oliver
Wu, Wentong Sept. 5, 2023, 8:53 a.m. UTC | #8
> From: Oliver Neukum <oneukum@suse.com>
> 
> On 05.09.23 04:20, Wu, Wentong wrote:
> 
> Hi,
> 
> >> That is that you will hang arbitrarily long in disconnect?
> > This routine isn't called in an interrupt context, and it allows sleep
> > or wait something before the real shutdown like many drivers' remove()
> > or
> > disconnect() do.
> 
> It is, however, in the context of a kernel thread. We can wait, but not for
> arbitrary periods.

AFAIK, this is very common.

> 
> > If we want to speed up the disconnect(), below changes is to complete
> > the cmd_completion if usb_kill_urb() has been called, but there is
> > still possibility ljca client init one more transfer before
> > auxiliary_device_delete()
> >
> > @@ -206,7 +206,11 @@ static void ljca_recv(struct urb *urb)
> >
> >          if (urb->status) {
> >                  /* sync/async unlink faults aren't errors */
> > -               if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
> > +               if (urb->status == -ENOENT) {
> > +                       complete(&adap->cmd_completion);
> > +                       return;
> 
> I'd say you'd break suspend() by such a change.
> You cannot complete in the interrupt handler, unless you can determine why the
> URB is killed.

With below status field in ljca_adapter to determine if it's killed by disconnect().

If this is preferred, I could cook the patch for review.

If this is fixed, could you please help merge this usb-ljca driver so that it won't
block others which depends on this driver?

BR,
Wentong
> 
> > +               }
> > +               if (urb->status == -ECONNRESET ||
> >                      urb->status == -ESHUTDOWN)
> >                          return;
> >
> > perhaps we could add one more 'status' field in ljca_adapter to
> > represent
> > disconnect() happen or not, and it will be checked in the beginning of
> > ljca_send() to avoid any new transfer.
> 
> That would be a solution.
> 
> 
> 	Regards
> 		Oliver
Greg KH Sept. 5, 2023, 10:04 a.m. UTC | #9
On Tue, Sep 05, 2023 at 08:53:43AM +0000, Wu, Wentong wrote:
> > From: Oliver Neukum <oneukum@suse.com>
> > 
> > On 05.09.23 04:20, Wu, Wentong wrote:
> > 
> > Hi,
> > 
> > >> That is that you will hang arbitrarily long in disconnect?
> > > This routine isn't called in an interrupt context, and it allows sleep
> > > or wait something before the real shutdown like many drivers' remove()
> > > or
> > > disconnect() do.
> > 
> > It is, however, in the context of a kernel thread. We can wait, but not for
> > arbitrary periods.
> 
> AFAIK, this is very common.
> 
> > 
> > > If we want to speed up the disconnect(), below changes is to complete
> > > the cmd_completion if usb_kill_urb() has been called, but there is
> > > still possibility ljca client init one more transfer before
> > > auxiliary_device_delete()
> > >
> > > @@ -206,7 +206,11 @@ static void ljca_recv(struct urb *urb)
> > >
> > >          if (urb->status) {
> > >                  /* sync/async unlink faults aren't errors */
> > > -               if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
> > > +               if (urb->status == -ENOENT) {
> > > +                       complete(&adap->cmd_completion);
> > > +                       return;
> > 
> > I'd say you'd break suspend() by such a change.
> > You cannot complete in the interrupt handler, unless you can determine why the
> > URB is killed.
> 
> With below status field in ljca_adapter to determine if it's killed by disconnect().
> 
> If this is preferred, I could cook the patch for review.
> 
> If this is fixed, could you please help merge this usb-ljca driver so that it won't
> block others which depends on this driver?

Please relax, we can't do anything until after -rc1 is out, and for me,
that includes reviewing the code.

There is no rush, or deadline, here at all.  It will be merged when it
is acceptable.

thanks,

greg k-h
Wu, Wentong Sept. 6, 2023, 3:29 a.m. UTC | #10
> From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>
> On Tue, Sep 05, 2023 at 08:53:43AM +0000, Wu, Wentong wrote:
> > > From: Oliver Neukum <oneukum@suse.com>
> > >
> > > On 05.09.23 04:20, Wu, Wentong wrote:
> > >
> > > Hi,
> > >
> > > >> That is that you will hang arbitrarily long in disconnect?
> > > > This routine isn't called in an interrupt context, and it allows
> > > > sleep or wait something before the real shutdown like many
> > > > drivers' remove() or
> > > > disconnect() do.
> > >
> > > It is, however, in the context of a kernel thread. We can wait, but
> > > not for arbitrary periods.
> >
> > AFAIK, this is very common.
> >
> > >
> > > > If we want to speed up the disconnect(), below changes is to
> > > > complete the cmd_completion if usb_kill_urb() has been called, but
> > > > there is still possibility ljca client init one more transfer
> > > > before
> > > > auxiliary_device_delete()
> > > >
> > > > @@ -206,7 +206,11 @@ static void ljca_recv(struct urb *urb)
> > > >
> > > >          if (urb->status) {
> > > >                  /* sync/async unlink faults aren't errors */
> > > > -               if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
> > > > +               if (urb->status == -ENOENT) {
> > > > +                       complete(&adap->cmd_completion);
> > > > +                       return;
> > >
> > > I'd say you'd break suspend() by such a change.
> > > You cannot complete in the interrupt handler, unless you can
> > > determine why the URB is killed.
> >
> > With below status field in ljca_adapter to determine if it's killed by disconnect().
> >
> > If this is preferred, I could cook the patch for review.
> >
> > If this is fixed, could you please help merge this usb-ljca driver so
> > that it won't block others which depends on this driver?
> 
> Please relax, we can't do anything until after -rc1 is out, and for me, that
> includes reviewing the code.

Thanks for your review.

> 
> There is no rush, or deadline, here at all.  It will be merged when it is acceptable.

Understood, thanks

BR,
Wentong
> 
> thanks,
> 
> greg k-h
diff mbox series

Patch

diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index 99b15b7..999193e 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -165,6 +165,20 @@  config APPLE_MFI_FASTCHARGE
 
 	  It is safe to say M here.
 
+config USB_LJCA
+	tristate "Intel La Jolla Cove Adapter support"
+	select AUXILIARY_BUS
+	depends on USB
+	depends on ACPI || COMPILE_TEST
+	help
+	  This adds support for Intel La Jolla Cove USB-I2C/SPI/GPIO
+	  Master Adapter (LJCA). Additional drivers such as I2C_LJCA,
+	  GPIO_LJCA and SPI_LJCA must be enabled in order to use the
+	  functionality of the device.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called usb-ljca.
+
 source "drivers/usb/misc/sisusbvga/Kconfig"
 
 config USB_LD
diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
index 1992cc2..0bc732bc 100644
--- a/drivers/usb/misc/Makefile
+++ b/drivers/usb/misc/Makefile
@@ -11,6 +11,7 @@  obj-$(CONFIG_USB_EMI26)			+= emi26.o
 obj-$(CONFIG_USB_EMI62)			+= emi62.o
 obj-$(CONFIG_USB_EZUSB_FX2)		+= ezusb.o
 obj-$(CONFIG_APPLE_MFI_FASTCHARGE)	+= apple-mfi-fastcharge.o
+obj-$(CONFIG_USB_LJCA)			+= usb-ljca.o
 obj-$(CONFIG_USB_IDMOUSE)		+= idmouse.o
 obj-$(CONFIG_USB_IOWARRIOR)		+= iowarrior.o
 obj-$(CONFIG_USB_ISIGHTFW)		+= isight_firmware.o
diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
new file mode 100644
index 0000000..942e850
--- /dev/null
+++ b/drivers/usb/misc/usb-ljca.c
@@ -0,0 +1,834 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel La Jolla Cove Adapter USB driver
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/dev_printk.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/usb.h>
+#include <linux/usb/ljca.h>
+
+/* command flags */
+#define LJCA_ACK_FLAG			BIT(0)
+#define LJCA_RESP_FLAG			BIT(1)
+#define LJCA_CMPL_FLAG			BIT(2)
+
+#define LJCA_MAX_PACKET_SIZE		64u
+#define LJCA_MAX_PAYLOAD_SIZE		\
+		(LJCA_MAX_PACKET_SIZE - sizeof(struct ljca_msg))
+
+#define LJCA_WRITE_TIMEOUT_MS		200
+#define LJCA_WRITE_ACK_TIMEOUT_MS	500
+#define LJCA_ENUM_CLIENT_TIMEOUT_MS	20
+
+/* ljca client type */
+enum ljca_client_type {
+	LJCA_CLIENT_MNG = 1,
+	LJCA_CLIENT_GPIO = 3,
+	LJCA_CLIENT_I2C = 4,
+	LJCA_CLIENT_SPI = 5,
+};
+
+/* MNG client commands */
+enum ljca_mng_cmd {
+	LJCA_MNG_RESET = 2,
+	LJCA_MNG_ENUM_GPIO = 4,
+	LJCA_MNG_ENUM_I2C = 5,
+	LJCA_MNG_ENUM_SPI = 8,
+};
+
+/* ljca client acpi _ADR */
+enum ljca_client_acpi_adr {
+	LJCA_GPIO_ACPI_ADR,
+	LJCA_I2C1_ACPI_ADR,
+	LJCA_I2C2_ACPI_ADR,
+	LJCA_SPI1_ACPI_ADR,
+	LJCA_SPI2_ACPI_ADR,
+	LJCA_CLIENT_ACPI_ADR_MAX,
+};
+
+/* ljca cmd message structure */
+struct ljca_msg {
+	u8 type;
+	u8 cmd;
+	u8 flags;
+	u8 len;
+	u8 data[];
+} __packed;
+
+struct ljca_i2c_ctr_info {
+	u8 id;
+	u8 capacity;
+	u8 intr_pin;
+} __packed;
+
+struct ljca_i2c_descriptor {
+	u8 num;
+	struct ljca_i2c_ctr_info info[];
+} __packed;
+
+struct ljca_spi_ctr_info {
+	u8 id;
+	u8 capacity;
+} __packed;
+
+struct ljca_spi_descriptor {
+	u8 num;
+	struct ljca_spi_ctr_info info[];
+} __packed;
+
+struct ljca_bank_descriptor {
+	u8 bank_id;
+	u8 pin_num;
+
+	/* 1 bit for each gpio, 1 means valid */
+	u32 valid_pins;
+} __packed;
+
+struct ljca_gpio_descriptor {
+	u8 pins_per_bank;
+	u8 bank_num;
+	struct ljca_bank_descriptor bank_desc[];
+} __packed;
+
+struct ljca_adapter {
+	struct usb_interface *intf;
+	struct usb_device *usb_dev;
+	struct device *dev;
+
+	unsigned int rx_pipe;
+	unsigned int tx_pipe;
+
+	/* urb for recv */
+	struct urb *rx_urb;
+	/* buffer for recv */
+	void *rx_buf;
+	unsigned int rx_len;
+
+	/* external buffer for recv */
+	void *ex_buf;
+	unsigned int ex_buf_len;
+	/* actual data length copied to external buffer */
+	unsigned int actual_length;
+
+	/* buffer for send */
+	void *tx_buf;
+	unsigned int tx_buf_len;
+
+	/* lock to protect tx_buf and ex_buf */
+	spinlock_t lock;
+
+	struct completion cmd_completion;
+
+	/* mutex to protect command download */
+	struct mutex mutex;
+
+	/* client device list */
+	struct list_head client_list;
+
+	/* used to reset firmware */
+	u32 reset_id;
+};
+
+static void ljca_handle_event(struct ljca_adapter *adap,
+			      struct ljca_msg *header)
+{
+	struct ljca_client *client;
+
+	list_for_each_entry(client, &adap->client_list, link) {
+		/*
+		 * FIXME: currently only GPIO register event callback.
+		 * firmware message structure should include id when
+		 * multiple same type clients register event callback.
+		 */
+		if (client->type == header->type) {
+			unsigned long flags;
+
+			spin_lock_irqsave(&client->event_cb_lock, flags);
+			client->event_cb(client->context, header->cmd,
+					 header->data, header->len);
+			spin_unlock_irqrestore(&client->event_cb_lock, flags);
+
+			break;
+		}
+	}
+}
+
+/* process command ack */
+static void ljca_handle_cmd_ack(struct ljca_adapter *adap,
+				struct ljca_msg *header)
+{
+	struct ljca_msg *tx_header = adap->tx_buf;
+	unsigned int actual_len = 0;
+	unsigned int ibuf_len;
+	unsigned long flags;
+	void *ibuf;
+
+	spin_lock_irqsave(&adap->lock, flags);
+
+	if (tx_header->type != header->type || tx_header->cmd != header->cmd) {
+		spin_unlock_irqrestore(&adap->lock, flags);
+
+		return;
+	}
+
+	ibuf_len = adap->ex_buf_len;
+	ibuf = adap->ex_buf;
+
+	if (ibuf && ibuf_len) {
+		actual_len = min_t(unsigned int, header->len, ibuf_len);
+
+		/* copy received data to external buffer */
+		memcpy(ibuf, header->data, actual_len);
+	}
+	/* update copied data length */
+	adap->actual_length = actual_len;
+
+	spin_unlock_irqrestore(&adap->lock, flags);
+
+	complete(&adap->cmd_completion);
+}
+
+static void ljca_recv(struct urb *urb)
+{
+	struct ljca_msg *header = urb->transfer_buffer;
+	struct ljca_adapter *adap = urb->context;
+	int ret;
+
+	if (urb->status) {
+		/* sync/async unlink faults aren't errors */
+		if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
+		    urb->status == -ESHUTDOWN)
+			return;
+
+		dev_err(adap->dev, "recv urb error: %d\n", urb->status);
+		goto resubmit;
+	}
+
+	if (header->len + sizeof(*header) != urb->actual_length)
+		goto resubmit;
+
+	if (header->flags & LJCA_ACK_FLAG)
+		ljca_handle_cmd_ack(adap, header);
+	else
+		ljca_handle_event(adap, header);
+
+resubmit:
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret && ret != -EPERM)
+		dev_err(adap->dev, "resubmit recv urb error %d\n", ret);
+}
+
+static int ljca_send(struct ljca_adapter *adap, u8 type, u8 cmd,
+		     const void *obuf, unsigned int obuf_len, void *ibuf,
+		     unsigned int ibuf_len, bool ack, unsigned long timeout)
+{
+	unsigned int msg_len = sizeof(struct ljca_msg) + obuf_len;
+	struct ljca_msg *header = adap->tx_buf;
+	unsigned long flags;
+	unsigned int actual;
+	int ret = 0;
+
+	if (msg_len > adap->tx_buf_len)
+		return -EINVAL;
+
+	mutex_lock(&adap->mutex);
+
+	spin_lock_irqsave(&adap->lock, flags);
+
+	header->type = type;
+	header->cmd = cmd;
+	header->len = obuf_len;
+	if (obuf)
+		memcpy(header->data, obuf, obuf_len);
+
+	header->flags = LJCA_CMPL_FLAG | (ack ? LJCA_ACK_FLAG : 0);
+
+	adap->ex_buf = ibuf;
+	adap->ex_buf_len = ibuf_len;
+	adap->actual_length = 0;
+
+	spin_unlock_irqrestore(&adap->lock, flags);
+
+	reinit_completion(&adap->cmd_completion);
+
+	usb_autopm_get_interface(adap->intf);
+
+	ret = usb_bulk_msg(adap->usb_dev, adap->tx_pipe, header,
+			   msg_len, &actual, LJCA_WRITE_TIMEOUT_MS);
+	if (!ret && ack) {
+		ret = wait_for_completion_timeout(&adap->cmd_completion,
+						  timeout);
+		if (ret < 0) {
+			goto out;
+		} if (!ret) {
+			ret = -ETIMEDOUT;
+			goto out;
+		}
+	}
+	ret = adap->actual_length;
+
+out:
+	spin_lock_irqsave(&adap->lock, flags);
+	adap->ex_buf = NULL;
+	adap->ex_buf_len = 0;
+
+	memset(header, 0, sizeof(*header));
+	spin_unlock_irqrestore(&adap->lock, flags);
+
+	usb_autopm_put_interface(adap->intf);
+
+	mutex_unlock(&adap->mutex);
+
+	return ret;
+}
+
+int ljca_transfer(struct ljca_client *client, u8 cmd, const void *obuf,
+		  unsigned int obuf_len, void *ibuf, unsigned int ibuf_len)
+{
+	return ljca_send(client->adapter, client->type, cmd,
+			 obuf, obuf_len, ibuf, ibuf_len, true,
+			 LJCA_WRITE_ACK_TIMEOUT_MS);
+}
+EXPORT_SYMBOL_NS_GPL(ljca_transfer, LJCA);
+
+int ljca_transfer_noack(struct ljca_client *client, u8 cmd, const void *obuf,
+			unsigned int obuf_len)
+{
+	return ljca_send(client->adapter, client->type, cmd, obuf,
+			 obuf_len, NULL, 0, false, LJCA_WRITE_ACK_TIMEOUT_MS);
+}
+EXPORT_SYMBOL_NS_GPL(ljca_transfer_noack, LJCA);
+
+int ljca_register_event_cb(struct ljca_client *client, ljca_event_cb_t event_cb,
+			   void *context)
+{
+	unsigned long flags;
+
+	if (!event_cb)
+		return -EINVAL;
+
+	spin_lock_irqsave(&client->event_cb_lock, flags);
+
+	if (client->event_cb) {
+		spin_unlock_irqrestore(&client->event_cb_lock, flags);
+		return -EALREADY;
+	}
+
+	client->event_cb = event_cb;
+	client->context = context;
+
+	spin_unlock_irqrestore(&client->event_cb_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(ljca_register_event_cb, LJCA);
+
+void ljca_unregister_event_cb(struct ljca_client *client)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&client->event_cb_lock, flags);
+
+	client->event_cb = NULL;
+	client->context = NULL;
+
+	spin_unlock_irqrestore(&client->event_cb_lock, flags);
+}
+EXPORT_SYMBOL_NS_GPL(ljca_unregister_event_cb, LJCA);
+
+#ifdef CONFIG_ACPI
+struct ljca_match_ids_walk_data {
+	const struct acpi_device_id *ids;
+	const char *uid;
+	struct acpi_device *adev;
+};
+
+static const struct acpi_device_id ljca_gpio_hids[] = {
+	{ "INTC1074" },
+	{ "INTC1096" },
+	{ "INTC100B" },
+	{ "INTC10D1" },
+	{},
+};
+
+static const struct acpi_device_id ljca_i2c_hids[] = {
+	{ "INTC1075" },
+	{ "INTC1097" },
+	{ "INTC100C" },
+	{ "INTC10D2" },
+	{},
+};
+
+static const struct acpi_device_id ljca_spi_hids[] = {
+	{ "INTC1091" },
+	{ "INTC1098" },
+	{ "INTC100D" },
+	{ "INTC10D3" },
+	{},
+};
+
+static int ljca_match_device_ids(struct acpi_device *adev, void *data)
+{
+	struct ljca_match_ids_walk_data *wd = data;
+	const char *uid = acpi_device_uid(adev);
+
+	if (acpi_match_device_ids(adev, wd->ids))
+		return 0;
+
+	if (!wd->uid)
+		goto match;
+
+	if (!uid)
+		uid = "0";
+	else
+		uid = memchr(uid, wd->uid[0], strlen(uid));
+
+	if (!uid || strcmp(uid, wd->uid))
+		return 0;
+
+match:
+	wd->adev = adev;
+
+	return 1;
+}
+
+/* bind auxiliary device to acpi device */
+static void ljca_auxdev_acpi_bind(struct ljca_adapter *adap,
+				  struct auxiliary_device *auxdev,
+				  u64 adr, u8 id)
+{
+	struct ljca_match_ids_walk_data wd = { 0 };
+	struct acpi_device *parent, *adev;
+	struct device *dev = adap->dev;
+	char uid[4];
+
+	parent = ACPI_COMPANION(dev);
+	if (!parent)
+		return;
+
+	/*
+	 * get auxdev ACPI handle from the ACPI device directly
+	 * under the parent that matches _ADR.
+	 */
+	adev = acpi_find_child_device(parent, adr, false);
+	if (adev) {
+		ACPI_COMPANION_SET(&auxdev->dev, adev);
+		return;
+	}
+
+	/*
+	 * _ADR is a grey area in the ACPI specification, some
+	 * platforms use _HID to distinguish children devices.
+	 */
+	switch (adr) {
+	case LJCA_GPIO_ACPI_ADR:
+		wd.ids = ljca_gpio_hids;
+		break;
+	case LJCA_I2C1_ACPI_ADR:
+	case LJCA_I2C2_ACPI_ADR:
+		snprintf(uid, sizeof(uid), "%d", id);
+		wd.uid = uid;
+		wd.ids = ljca_i2c_hids;
+		break;
+	case LJCA_SPI1_ACPI_ADR:
+	case LJCA_SPI2_ACPI_ADR:
+		wd.ids = ljca_spi_hids;
+		break;
+	default:
+		dev_warn(dev, "unsupported _ADR\n");
+		return;
+	}
+
+	acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
+	if (wd.adev) {
+		ACPI_COMPANION_SET(&auxdev->dev, wd.adev);
+		return;
+	}
+
+	parent = ACPI_COMPANION(dev->parent->parent);
+	if (!parent)
+		return;
+
+	acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
+	if (wd.adev)
+		ACPI_COMPANION_SET(&auxdev->dev, wd.adev);
+}
+#else
+static void ljca_auxdev_acpi_bind(struct ljca_adapter *adap,
+				  struct auxiliary_device *auxdev,
+				  u64 adr, u8 id)
+{
+}
+#endif
+
+static void ljca_auxdev_release(struct device *dev)
+{
+	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
+
+	kfree(auxdev->dev.platform_data);
+}
+
+static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
+				  char *name, void *data, u64 adr)
+{
+	struct auxiliary_device *auxdev;
+	struct ljca_client *client;
+	int ret;
+
+	client = kzalloc(sizeof *client, GFP_KERNEL);
+	if (!client)
+		return -ENOMEM;
+
+	client->type = type;
+	client->id = id;
+	client->adapter = adap;
+	spin_lock_init(&client->event_cb_lock);
+
+	auxdev = &client->auxdev;
+	auxdev->name = name;
+	auxdev->id = id;
+
+	auxdev->dev.parent = adap->dev;
+	auxdev->dev.platform_data = data;
+	auxdev->dev.release = ljca_auxdev_release;
+
+	ret = auxiliary_device_init(auxdev);
+	if (ret)
+		goto err_free;
+
+	ljca_auxdev_acpi_bind(adap, auxdev, adr, id);
+
+	ret = auxiliary_device_add(auxdev);
+	if (ret)
+		goto err_uninit;
+
+	list_add_tail(&client->link, &adap->client_list);
+
+	return 0;
+
+err_uninit:
+	auxiliary_device_uninit(auxdev);
+
+err_free:
+	kfree(client);
+
+	return ret;
+}
+
+static int ljca_enumerate_gpio(struct ljca_adapter *adap)
+{
+	u32 valid_pin[LJCA_MAX_GPIO_NUM / BITS_PER_TYPE(u32)];
+	struct ljca_gpio_descriptor *desc;
+	struct ljca_gpio_info *gpio_info;
+	u8 buf[LJCA_MAX_PAYLOAD_SIZE];
+	int ret, gpio_num;
+	unsigned int i;
+
+	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_ENUM_GPIO, NULL, 0, buf,
+			sizeof(buf), true, LJCA_ENUM_CLIENT_TIMEOUT_MS);
+	if (ret < 0)
+		return ret;
+
+	/* check firmware response */
+	desc = (struct ljca_gpio_descriptor *)buf;
+	if (ret != struct_size(desc, bank_desc, desc->bank_num))
+		return -EINVAL;
+
+	gpio_num = desc->pins_per_bank * desc->bank_num;
+	if (gpio_num > LJCA_MAX_GPIO_NUM)
+		return -EINVAL;
+
+	/* construct platform data */
+	gpio_info = kzalloc(sizeof *gpio_info, GFP_KERNEL);
+	if (!gpio_info)
+		return -ENOMEM;
+	gpio_info->num = gpio_num;
+
+	for (i = 0; i < desc->bank_num; i++)
+		valid_pin[i] = desc->bank_desc[i].valid_pins;
+	bitmap_from_arr32(gpio_info->valid_pin_map, valid_pin, gpio_num);
+
+	ret = ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
+				     gpio_info, LJCA_GPIO_ACPI_ADR);
+	if (ret)
+		kfree(gpio_info);
+
+	return ret;
+}
+
+static int ljca_enumerate_i2c(struct ljca_adapter *adap)
+{
+	struct ljca_i2c_descriptor *desc;
+	struct ljca_i2c_info *i2c_info;
+	u8 buf[LJCA_MAX_PAYLOAD_SIZE];
+	unsigned int i;
+	int ret;
+
+	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_ENUM_I2C, NULL, 0, buf,
+			sizeof(buf), true, LJCA_ENUM_CLIENT_TIMEOUT_MS);
+	if (ret < 0)
+		return ret;
+
+	/* check firmware response */
+	desc = (struct ljca_i2c_descriptor *)buf;
+	if (ret != struct_size(desc, info, desc->num))
+		return -EINVAL;
+
+	for (i = 0; i < desc->num; i++) {
+		/* construct platform data */
+		i2c_info = kzalloc(sizeof *i2c_info, GFP_KERNEL);
+		if (!i2c_info)
+			return -ENOMEM;
+
+		i2c_info->id = desc->info[i].id;
+		i2c_info->capacity = desc->info[i].capacity;
+		i2c_info->intr_pin = desc->info[i].intr_pin;
+
+		ret = ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
+					     "ljca-i2c", i2c_info,
+					     LJCA_I2C1_ACPI_ADR + i);
+		if (ret) {
+			kfree(i2c_info);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int ljca_enumerate_spi(struct ljca_adapter *adap)
+{
+	struct ljca_spi_descriptor *desc;
+	struct ljca_spi_info *spi_info;
+	u8 buf[LJCA_MAX_PAYLOAD_SIZE];
+	unsigned int i;
+	int ret;
+
+	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_ENUM_SPI, NULL, 0, buf,
+			sizeof(buf), true, LJCA_ENUM_CLIENT_TIMEOUT_MS);
+	if (ret < 0)
+		return ret;
+
+	desc = (struct ljca_spi_descriptor *)buf;
+	for (i = 0; i < desc->num; i++) {
+		/* construct platform data */
+		spi_info = kzalloc(sizeof *spi_info, GFP_KERNEL);
+		if (!spi_info)
+			return -ENOMEM;
+
+		spi_info->id = desc->info[i].id;
+		spi_info->capacity = desc->info[i].capacity;
+
+		ret = ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
+					     "ljca-spi", spi_info,
+					     LJCA_SPI1_ACPI_ADR + i);
+		if (ret) {
+			kfree(spi_info);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int ljca_reset_handshake(struct ljca_adapter *adap)
+{
+	__le32 reset_id = cpu_to_le32(adap->reset_id);
+	__le32 reset_id_ret = 0;
+	int ret;
+
+	adap->reset_id++;
+
+	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_RESET, &reset_id,
+			sizeof(__le32), &reset_id_ret, sizeof(__le32), true,
+			LJCA_WRITE_ACK_TIMEOUT_MS);
+	if (ret < 0)
+		return ret;
+
+	if (reset_id_ret != reset_id)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ljca_enumerate_clients(struct ljca_adapter *adap)
+{
+	int ret;
+
+	ret = ljca_reset_handshake(adap);
+	if (ret)
+		return ret;
+
+	ret = ljca_enumerate_gpio(adap);
+	if (ret)
+		dev_warn(adap->dev, "enumerate GPIO error\n");
+
+	ret = ljca_enumerate_i2c(adap);
+	if (ret)
+		dev_warn(adap->dev, "enumerate I2C error\n");
+
+	ret = ljca_enumerate_spi(adap);
+	if (ret)
+		dev_warn(adap->dev, "enumerate SPI error\n");
+
+	return 0;
+}
+
+static int ljca_probe(struct usb_interface *interface,
+		      const struct usb_device_id *id)
+{
+	struct usb_device *usb_dev = interface_to_usbdev(interface);
+	struct usb_host_interface *alt = interface->cur_altsetting;
+	struct usb_endpoint_descriptor *ep_in, *ep_out;
+	struct device *dev = &interface->dev;
+	struct ljca_adapter *adap;
+	int ret;
+
+	adap = devm_kzalloc(dev, sizeof(*adap), GFP_KERNEL);
+	if (!adap)
+		return -ENOMEM;
+
+	/* separate tx buffer allocation for alignment */
+	adap->tx_buf = devm_kzalloc(dev, LJCA_MAX_PACKET_SIZE, GFP_KERNEL);
+	if (!adap->tx_buf)
+		return -ENOMEM;
+	adap->tx_buf_len = LJCA_MAX_PACKET_SIZE;
+
+	mutex_init(&adap->mutex);
+	spin_lock_init(&adap->lock);
+	init_completion(&adap->cmd_completion);
+	INIT_LIST_HEAD(&adap->client_list);
+
+	adap->intf = usb_get_intf(interface);
+	adap->usb_dev = usb_dev;
+	adap->dev = dev;
+
+	/*
+	 * find the first bulk in and out endpoints.
+	 * ignore any others.
+	 */
+	ret = usb_find_common_endpoints(alt, &ep_in, &ep_out, NULL, NULL);
+	if (ret) {
+		dev_err(dev, "bulk endpoints not found\n");
+		goto err;
+	}
+	adap->rx_pipe = usb_rcvbulkpipe(usb_dev, usb_endpoint_num(ep_in));
+	adap->tx_pipe = usb_sndbulkpipe(usb_dev, usb_endpoint_num(ep_out));
+
+	/* setup rx buffer */
+	adap->rx_len = usb_endpoint_maxp(ep_in);
+	adap->rx_buf = devm_kzalloc(dev, adap->rx_len, GFP_KERNEL);
+	if (!adap->rx_buf) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	/* alloc rx urb */
+	adap->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!adap->rx_urb) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	usb_fill_bulk_urb(adap->rx_urb, usb_dev, adap->rx_pipe,
+			  adap->rx_buf, adap->rx_len, ljca_recv, adap);
+
+	usb_set_intfdata(interface, adap);
+
+	/* submit rx urb before enumerate clients */
+	ret = usb_submit_urb(adap->rx_urb, GFP_KERNEL);
+	if (ret) {
+		dev_err(dev, "submit rx urb failed: %d\n", ret);
+		goto err_free;
+	}
+
+	ret = ljca_enumerate_clients(adap);
+	if (ret)
+		goto err_kill;
+
+	usb_enable_autosuspend(usb_dev);
+
+	return 0;
+
+err_kill:
+	usb_kill_urb(adap->rx_urb);
+
+err_free:
+	usb_free_urb(adap->rx_urb);
+
+err:
+	usb_put_intf(adap->intf);
+	mutex_destroy(&adap->mutex);
+
+	return ret;
+}
+
+static void ljca_disconnect(struct usb_interface *interface)
+{
+	struct ljca_adapter *adap = usb_get_intfdata(interface);
+	struct ljca_client *client, *next;
+
+	usb_kill_urb(adap->rx_urb);
+
+	list_for_each_entry_safe(client, next, &adap->client_list, link) {
+		auxiliary_device_delete(&client->auxdev);
+		auxiliary_device_uninit(&client->auxdev);
+
+		list_del_init(&client->link);
+		kfree(client);
+	}
+
+	usb_free_urb(adap->rx_urb);
+
+	usb_put_intf(adap->intf);
+
+	mutex_destroy(&adap->mutex);
+}
+
+static int ljca_suspend(struct usb_interface *interface, pm_message_t message)
+{
+	struct ljca_adapter *adap = usb_get_intfdata(interface);
+
+	usb_kill_urb(adap->rx_urb);
+
+	return 0;
+}
+
+static int ljca_resume(struct usb_interface *interface)
+{
+	struct ljca_adapter *adap = usb_get_intfdata(interface);
+
+	return usb_submit_urb(adap->rx_urb, GFP_KERNEL);
+}
+
+static const struct usb_device_id ljca_table[] = {
+	{ USB_DEVICE(0x8086, 0x0b63) },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(usb, ljca_table);
+
+static struct usb_driver ljca_driver = {
+	.name = "ljca",
+	.id_table = ljca_table,
+	.probe = ljca_probe,
+	.disconnect = ljca_disconnect,
+	.suspend = ljca_suspend,
+	.resume = ljca_resume,
+	.supports_autosuspend = 1,
+};
+module_usb_driver(ljca_driver);
+
+MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
+MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
+MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");
+MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/usb/ljca.h b/include/linux/usb/ljca.h
new file mode 100644
index 0000000..6eadd43
--- /dev/null
+++ b/include/linux/usb/ljca.h
@@ -0,0 +1,113 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2023, Intel Corporation. All rights reserved.
+ */
+#ifndef _LINUX_USB_LJCA_H_
+#define _LINUX_USB_LJCA_H_
+
+#include <linux/auxiliary_bus.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#define LJCA_MAX_GPIO_NUM 64
+
+#define auxiliary_dev_to_ljca_client(auxiliary_dev)			\
+		container_of(auxiliary_dev, struct ljca_client, auxdev)
+
+struct ljca_adapter;
+
+/**
+ * typedef ljca_event_cb_t - event callback function signature
+ *
+ * @context: the execution context of who registered this callback
+ * @cmd: the command from device for this event
+ * @evt_data: the event data payload
+ * @len: the event data payload length
+ *
+ * The callback function is called in interrupt context and the data payload is
+ * only valid during the call. If the user needs later access of the data, it
+ * must copy it.
+ */
+typedef void (*ljca_event_cb_t)(void *context, u8 cmd, const void *evt_data, int len);
+
+struct ljca_client {
+	u8 type;
+	u8 id;
+	struct list_head link;
+	struct auxiliary_device auxdev;
+	struct ljca_adapter *adapter;
+
+	void *context;
+	ljca_event_cb_t event_cb;
+	/* lock to protect event_cb */
+	spinlock_t event_cb_lock;
+};
+
+struct ljca_gpio_info {
+	unsigned int num;
+	DECLARE_BITMAP(valid_pin_map, LJCA_MAX_GPIO_NUM);
+};
+
+struct ljca_i2c_info {
+	u8 id;
+	u8 capacity;
+	u8 intr_pin;
+};
+
+struct ljca_spi_info {
+	u8 id;
+	u8 capacity;
+};
+
+/**
+ * ljca_register_event_cb - register a callback function to receive events
+ *
+ * @client: ljca client device
+ * @event_cb: callback function
+ * @context: execution context of event callback
+ *
+ * Return: 0 in case of success, negative value in case of error
+ */
+int ljca_register_event_cb(struct ljca_client *client, ljca_event_cb_t event_cb, void *context);
+
+/**
+ * ljca_unregister_event_cb - unregister the callback function for an event
+ *
+ * @client: ljca client device
+ */
+void ljca_unregister_event_cb(struct ljca_client *client);
+
+/**
+ * ljca_transfer - issue a LJCA command and wait for a response
+ *
+ * @client: ljca client device
+ * @cmd: the command to be sent to the device
+ * @obuf: the buffer to be sent to the device; it can be NULL if the user
+ *	doesn't need to transmit data with this command
+ * @obuf_len: the size of the buffer to be sent to the device; it should
+ *	be 0 when obuf is NULL
+ * @ibuf: any data associated with the response will be copied here; it can be
+ *	NULL if the user doesn't need the response data
+ * @ibuf_len: must be initialized to the input buffer size
+ *
+ * Return: the actual length data transferred for success, negative value for errors
+ */
+int ljca_transfer(struct ljca_client *client, u8 cmd, const void *obuf,
+		  unsigned int obuf_len, void *ibuf, unsigned int ibuf_len);
+
+/**
+ * ljca_transfer_noack - issue a LJCA command without a response
+ *
+ * @client: ljca client device
+ * @cmd: the command to be sent to the device
+ * @obuf: the buffer to be sent to the device; it can be NULL if the user
+ *	doesn't need to transmit data with this command
+ * @obuf_len: the size of the buffer to be sent to the device
+ *
+ * Return: 0 for success, negative value for errors
+ */
+int ljca_transfer_noack(struct ljca_client *client, u8 cmd, const void *obuf,
+			unsigned int obuf_len);
+
+#endif