diff mbox series

[v16,1/4] usb: Add support for Intel LJCA device

Message ID 1694569212-10080-2-git-send-email-wentong.wu@intel.com
State Superseded
Headers show
Series Add Intel LJCA device driver | expand

Commit Message

Wu, Wentong Sept. 13, 2023, 1:40 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 | 835 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/usb/ljca.h    | 145 ++++++++
 4 files changed, 995 insertions(+)
 create mode 100644 drivers/usb/misc/usb-ljca.c
 create mode 100644 include/linux/usb/ljca.h

Comments

kernel test robot Sept. 13, 2023, 6:12 a.m. UTC | #1
Hi Wentong,

kernel test robot noticed the following build warnings:

[auto build test WARNING on wsa/i2c/for-next]
[also build test WARNING on broonie-spi/for-next linus/master v6.6-rc1 next-20230912]
[cannot apply to usb/usb-testing usb/usb-next usb/usb-linus]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Wentong-Wu/usb-Add-support-for-Intel-LJCA-device/20230913-094239
base:   https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next
patch link:    https://lore.kernel.org/r/1694569212-10080-2-git-send-email-wentong.wu%40intel.com
patch subject: [PATCH v16 1/4] usb: Add support for Intel LJCA device
config: sparc-allyesconfig (https://download.01.org/0day-ci/archive/20230913/202309131427.AUBwVNBm-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230913/202309131427.AUBwVNBm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309131427.AUBwVNBm-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/usb/misc/usb-ljca.c: In function 'ljca_match_device_ids':
   drivers/usb/misc/usb-ljca.c:389:27: error: implicit declaration of function 'acpi_device_uid'; did you mean 'dmi_device_id'? [-Werror=implicit-function-declaration]
     389 |         const char *uid = acpi_device_uid(adev);
         |                           ^~~~~~~~~~~~~~~
         |                           dmi_device_id
>> drivers/usb/misc/usb-ljca.c:389:27: warning: initialization of 'const char *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   drivers/usb/misc/usb-ljca.c:391:13: error: implicit declaration of function 'acpi_match_device_ids'; did you mean 'ljca_match_device_ids'? [-Werror=implicit-function-declaration]
     391 |         if (acpi_match_device_ids(adev, wd->ids))
         |             ^~~~~~~~~~~~~~~~~~~~~
         |             ljca_match_device_ids
   drivers/usb/misc/usb-ljca.c: In function 'ljca_auxdev_acpi_bind':
   drivers/usb/misc/usb-ljca.c:429:16: error: implicit declaration of function 'acpi_find_child_device'; did you mean 'acpi_match_device'? [-Werror=implicit-function-declaration]
     429 |         adev = acpi_find_child_device(parent, adr, false);
         |                ^~~~~~~~~~~~~~~~~~~~~~
         |                acpi_match_device
>> drivers/usb/misc/usb-ljca.c:429:14: warning: assignment to 'struct acpi_device *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
     429 |         adev = acpi_find_child_device(parent, adr, false);
         |              ^
   drivers/usb/misc/usb-ljca.c:458:9: error: implicit declaration of function 'acpi_dev_for_each_child'; did you mean 'device_for_each_child'? [-Werror=implicit-function-declaration]
     458 |         acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
         |         ^~~~~~~~~~~~~~~~~~~~~~~
         |         device_for_each_child
   cc1: some warnings being treated as errors


vim +389 drivers/usb/misc/usb-ljca.c

   385	
   386	static int ljca_match_device_ids(struct acpi_device *adev, void *data)
   387	{
   388		struct ljca_match_ids_walk_data *wd = data;
 > 389		const char *uid = acpi_device_uid(adev);
   390	
   391		if (acpi_match_device_ids(adev, wd->ids))
   392			return 0;
   393	
   394		if (!wd->uid)
   395			goto match;
   396	
   397		if (!uid)
   398			uid = "0";
   399		else
   400			uid = strchr(uid, wd->uid[0]);
   401	
   402		if (!uid || strcmp(uid, wd->uid))
   403			return 0;
   404	
   405	match:
   406		wd->adev = adev;
   407	
   408		return 1;
   409	}
   410	
   411	/* bind auxiliary device to acpi device */
   412	static void ljca_auxdev_acpi_bind(struct ljca_adapter *adap,
   413					  struct auxiliary_device *auxdev,
   414					  u64 adr, u8 id)
   415	{
   416		struct ljca_match_ids_walk_data wd = { 0 };
   417		struct acpi_device *parent, *adev;
   418		struct device *dev = adap->dev;
   419		char uid[4];
   420	
   421		parent = ACPI_COMPANION(dev);
   422		if (!parent)
   423			return;
   424	
   425		/*
   426		 * get auxdev ACPI handle from the ACPI device directly
   427		 * under the parent that matches _ADR.
   428		 */
 > 429		adev = acpi_find_child_device(parent, adr, false);
   430		if (adev) {
   431			ACPI_COMPANION_SET(&auxdev->dev, adev);
   432			return;
   433		}
   434	
   435		/*
   436		 * _ADR is a grey area in the ACPI specification, some
   437		 * platforms use _HID to distinguish children devices.
   438		 */
   439		switch (adr) {
   440		case LJCA_GPIO_ACPI_ADR:
   441			wd.ids = ljca_gpio_hids;
   442			break;
   443		case LJCA_I2C1_ACPI_ADR:
   444		case LJCA_I2C2_ACPI_ADR:
   445			snprintf(uid, sizeof(uid), "%d", id);
   446			wd.uid = uid;
   447			wd.ids = ljca_i2c_hids;
   448			break;
   449		case LJCA_SPI1_ACPI_ADR:
   450		case LJCA_SPI2_ACPI_ADR:
   451			wd.ids = ljca_spi_hids;
   452			break;
   453		default:
   454			dev_warn(dev, "unsupported _ADR\n");
   455			return;
   456		}
   457	
   458		acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
   459		if (wd.adev) {
   460			ACPI_COMPANION_SET(&auxdev->dev, wd.adev);
   461			return;
   462		}
   463	
   464		parent = ACPI_COMPANION(dev->parent->parent);
   465		if (!parent)
   466			return;
   467	
   468		acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
   469		if (wd.adev)
   470			ACPI_COMPANION_SET(&auxdev->dev, wd.adev);
   471	}
   472
Hans de Goede Sept. 13, 2023, 7:26 a.m. UTC | #2
Hi,

On 9/13/23 08:12, kernel test robot wrote:
> Hi Wentong,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on wsa/i2c/for-next]
> [also build test WARNING on broonie-spi/for-next linus/master v6.6-rc1 next-20230912]
> [cannot apply to usb/usb-testing usb/usb-next usb/usb-linus]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Wentong-Wu/usb-Add-support-for-Intel-LJCA-device/20230913-094239
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next
> patch link:    https://lore.kernel.org/r/1694569212-10080-2-git-send-email-wentong.wu%40intel.com
> patch subject: [PATCH v16 1/4] usb: Add support for Intel LJCA device
> config: sparc-allyesconfig (https://download.01.org/0day-ci/archive/20230913/202309131427.AUBwVNBm-lkp@intel.com/config)
> compiler: sparc64-linux-gcc (GCC) 13.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230913/202309131427.AUBwVNBm-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202309131427.AUBwVNBm-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    drivers/usb/misc/usb-ljca.c: In function 'ljca_match_device_ids':
>    drivers/usb/misc/usb-ljca.c:389:27: error: implicit declaration of function 'acpi_device_uid'; did you mean 'dmi_device_id'? [-Werror=implicit-function-declaration]
>      389 |         const char *uid = acpi_device_uid(adev);
>          |                           ^~~~~~~~~~~~~~~
>          |                           dmi_device_id
>>> drivers/usb/misc/usb-ljca.c:389:27: warning: initialization of 'const char *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
>    drivers/usb/misc/usb-ljca.c:391:13: error: implicit declaration of function 'acpi_match_device_ids'; did you mean 'ljca_match_device_ids'? [-Werror=implicit-function-declaration]
>      391 |         if (acpi_match_device_ids(adev, wd->ids))
>          |             ^~~~~~~~~~~~~~~~~~~~~
>          |             ljca_match_device_ids
>    drivers/usb/misc/usb-ljca.c: In function 'ljca_auxdev_acpi_bind':
>    drivers/usb/misc/usb-ljca.c:429:16: error: implicit declaration of function 'acpi_find_child_device'; did you mean 'acpi_match_device'? [-Werror=implicit-function-declaration]
>      429 |         adev = acpi_find_child_device(parent, adr, false);
>          |                ^~~~~~~~~~~~~~~~~~~~~~
>          |                acpi_match_device
>>> drivers/usb/misc/usb-ljca.c:429:14: warning: assignment to 'struct acpi_device *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
>      429 |         adev = acpi_find_child_device(parent, adr, false);
>          |              ^
>    drivers/usb/misc/usb-ljca.c:458:9: error: implicit declaration of function 'acpi_dev_for_each_child'; did you mean 'device_for_each_child'? [-Werror=implicit-function-declaration]
>      458 |         acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
>          |         ^~~~~~~~~~~~~~~~~~~~~~~
>          |         device_for_each_child
>    cc1: some warnings being treated as errors

Ok, so this need to have a "depends on ACPI" added to its Kconfig
entry. There are other ways to fix it, but this driver will not
be functional without ACPI anyways so "depends on ACPI" seems
to be the best solution for this.

Regards,

Hans





> vim +389 drivers/usb/misc/usb-ljca.c
> 
>    385	
>    386	static int ljca_match_device_ids(struct acpi_device *adev, void *data)
>    387	{
>    388		struct ljca_match_ids_walk_data *wd = data;
>  > 389		const char *uid = acpi_device_uid(adev);
>    390	
>    391		if (acpi_match_device_ids(adev, wd->ids))
>    392			return 0;
>    393	
>    394		if (!wd->uid)
>    395			goto match;
>    396	
>    397		if (!uid)
>    398			uid = "0";
>    399		else
>    400			uid = strchr(uid, wd->uid[0]);
>    401	
>    402		if (!uid || strcmp(uid, wd->uid))
>    403			return 0;
>    404	
>    405	match:
>    406		wd->adev = adev;
>    407	
>    408		return 1;
>    409	}
>    410	
>    411	/* bind auxiliary device to acpi device */
>    412	static void ljca_auxdev_acpi_bind(struct ljca_adapter *adap,
>    413					  struct auxiliary_device *auxdev,
>    414					  u64 adr, u8 id)
>    415	{
>    416		struct ljca_match_ids_walk_data wd = { 0 };
>    417		struct acpi_device *parent, *adev;
>    418		struct device *dev = adap->dev;
>    419		char uid[4];
>    420	
>    421		parent = ACPI_COMPANION(dev);
>    422		if (!parent)
>    423			return;
>    424	
>    425		/*
>    426		 * get auxdev ACPI handle from the ACPI device directly
>    427		 * under the parent that matches _ADR.
>    428		 */
>  > 429		adev = acpi_find_child_device(parent, adr, false);
>    430		if (adev) {
>    431			ACPI_COMPANION_SET(&auxdev->dev, adev);
>    432			return;
>    433		}
>    434	
>    435		/*
>    436		 * _ADR is a grey area in the ACPI specification, some
>    437		 * platforms use _HID to distinguish children devices.
>    438		 */
>    439		switch (adr) {
>    440		case LJCA_GPIO_ACPI_ADR:
>    441			wd.ids = ljca_gpio_hids;
>    442			break;
>    443		case LJCA_I2C1_ACPI_ADR:
>    444		case LJCA_I2C2_ACPI_ADR:
>    445			snprintf(uid, sizeof(uid), "%d", id);
>    446			wd.uid = uid;
>    447			wd.ids = ljca_i2c_hids;
>    448			break;
>    449		case LJCA_SPI1_ACPI_ADR:
>    450		case LJCA_SPI2_ACPI_ADR:
>    451			wd.ids = ljca_spi_hids;
>    452			break;
>    453		default:
>    454			dev_warn(dev, "unsupported _ADR\n");
>    455			return;
>    456		}
>    457	
>    458		acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
>    459		if (wd.adev) {
>    460			ACPI_COMPANION_SET(&auxdev->dev, wd.adev);
>    461			return;
>    462		}
>    463	
>    464		parent = ACPI_COMPANION(dev->parent->parent);
>    465		if (!parent)
>    466			return;
>    467	
>    468		acpi_dev_for_each_child(parent, ljca_match_device_ids, &wd);
>    469		if (wd.adev)
>    470			ACPI_COMPANION_SET(&auxdev->dev, wd.adev);
>    471	}
>    472	
>
Oliver Neukum Sept. 13, 2023, 9:03 a.m. UTC | #3
On 13.09.23 03:40, Wentong Wu wrote:

> +struct ljca_bank_descriptor {
> +	u8 bank_id;
> +	u8 pin_num;
> +
> +	/* 1 bit for each gpio, 1 means valid */
> +	u32 valid_pins;

No endianness?

> +} __packed;

	Regards
		Oliver
Wu, Wentong Sept. 14, 2023, 1:05 a.m. UTC | #4
> From: Oliver Neukum <oneukum@suse.com>
>
> On 13.09.23 03:40, Wentong Wu wrote:
> 
> > +struct ljca_bank_descriptor {
> > +	u8 bank_id;
> > +	u8 pin_num;
> > +
> > +	/* 1 bit for each gpio, 1 means valid */
> > +	u32 valid_pins;
> 
> No endianness?

On both sides, the endianness is same.

BTW, the code has been tested on several real productions.

BR,
Wentong
> 
> > +} __packed;
> 
> 	Regards
> 		Oliver
Hans de Goede Sept. 14, 2023, 8:21 a.m. UTC | #5
Hi,

On 9/14/23 03:05, Wu, Wentong wrote:
>> From: Oliver Neukum <oneukum@suse.com>
>>
>> On 13.09.23 03:40, Wentong Wu wrote:
>>
>>> +struct ljca_bank_descriptor {
>>> +	u8 bank_id;
>>> +	u8 pin_num;
>>> +
>>> +	/* 1 bit for each gpio, 1 means valid */
>>> +	u32 valid_pins;
>>
>> No endianness?
> 
> On both sides, the endianness is same.

Right, but normally USB drivers are also written so that they can work on big-endian CPUs.

I realize that this driver will likely never be used with a big-endian CPU but still it is good practice to make the driver work on big-endian CPUs too. Even if it is just to set a good example when other drivers copy the code.

So this should be:

struct ljca_bank_descriptor {
	u8 bank_id;
	u8 pin_num;

	/* 1 bit for each gpio, 1 means valid */
	__le32 valid_pins;
} __packed;

And then when reading valid_pins you should use:

	u32 valid_pins = get_unaligned_le32(&ljca_bank_descriptor.valid_pins);

On x86_64 the compiler should optimize all of this away to
just a regular read.

Regards,

Hans
Wu, Wentong Sept. 14, 2023, 8:58 a.m. UTC | #6
> From: Hans de Goede <hdegoede@redhat.com>
> 
> Hi,
> 
> On 9/14/23 03:05, Wu, Wentong wrote:
> >> From: Oliver Neukum <oneukum@suse.com>
> >>
> >> On 13.09.23 03:40, Wentong Wu wrote:
> >>
> >>> +struct ljca_bank_descriptor {
> >>> +	u8 bank_id;
> >>> +	u8 pin_num;
> >>> +
> >>> +	/* 1 bit for each gpio, 1 means valid */
> >>> +	u32 valid_pins;
> >>
> >> No endianness?
> >
> > On both sides, the endianness is same.
> 
> Right, but normally USB drivers are also written so that they can work on big-
> endian CPUs.
> 
> I realize that this driver will likely never be used with a big-endian CPU but still it
> is good practice to make the driver work on big-endian CPUs too. Even if it is just
> to set a good example when other drivers copy the code.

Thanks, I agree the point here.

And I will update the driver after the test, thanks again.

BR,
Wentong
>
> 
> So this should be:
> 
> struct ljca_bank_descriptor {
> 	u8 bank_id;
> 	u8 pin_num;
> 
> 	/* 1 bit for each gpio, 1 means valid */
> 	__le32 valid_pins;
> } __packed;
> 
> And then when reading valid_pins you should use:
> 
> 	u32 valid_pins = get_unaligned_le32(&ljca_bank_descriptor.valid_pins);
> 
> On x86_64 the compiler should optimize all of this away to just a regular read.
> 
> Regards,
> 
> Hans
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..0d5a77d
--- /dev/null
+++ b/drivers/usb/misc/usb-ljca.c
@@ -0,0 +1,835 @@ 
+// 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/cleanup.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/spinlock.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 */
+	u8 *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;
+
+	/* disconnect ongoing or not */
+	bool disconnect;
+
+	/* used to reset firmware */
+	u32 reset_id;
+};
+
+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 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) {
+			scoped_guard(spinlock_irqsave, &client->event_cb_lock) {
+				client->event_cb(client->context, header->cmd,
+						 header->data, header->len);
+			}
+
+			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;
+	u8 *ibuf;
+
+	spin_lock_irqsave(&adap->lock, flags);
+
+	if (tx_header->type != header->type || tx_header->cmd != header->cmd) {
+		dev_err(adap->dev, "cmd ack mismatch error\n");
+		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) {
+			/*
+			 * directly complete the possible ongoing transfer
+			 * during disconnect
+			 */
+			if (adap->disconnect)
+				complete(&adap->cmd_completion);
+			return;
+		}
+
+		if (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 u8 *obuf, unsigned int obuf_len, u8 *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 int actual;
+	int ret = 0;
+
+	if (adap->disconnect)
+		return -ENODEV;
+
+	if (msg_len > adap->tx_buf_len)
+		return -EINVAL;
+
+	mutex_lock(&adap->mutex);
+
+	scoped_guard(spinlock_irqsave, &adap->lock) {
+		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;
+	}
+
+	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);
+
+	usb_autopm_put_interface(adap->intf);
+
+	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:
+	scoped_guard(spinlock_irqsave, &adap->lock) {
+		adap->ex_buf = NULL;
+		adap->ex_buf_len = 0;
+		memset(header, 0, sizeof(*header));
+	}
+
+	mutex_unlock(&adap->mutex);
+
+	return ret;
+}
+
+int ljca_transfer(struct ljca_client *client, u8 cmd, const u8 *obuf,
+		  unsigned int obuf_len, u8 *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 u8 *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)
+{
+	scoped_guard(spinlock_irqsave, &client->event_cb_lock) {
+		client->event_cb = NULL;
+		client->context = NULL;
+	}
+}
+EXPORT_SYMBOL_NS_GPL(ljca_unregister_event_cb, LJCA);
+
+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 = strchr(uid, wd->uid[0]);
+
+	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);
+}
+
+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, (u8 *)&reset_id,
+			sizeof(__le32), (u8 *)&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;
+
+	adap->disconnect = true;
+
+	usb_kill_urb(adap->rx_urb);
+
+	list_for_each_entry_safe_reverse(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..502fc8b
--- /dev/null
+++ b/include/linux/usb/ljca.h
@@ -0,0 +1,145 @@ 
+/* 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 - represent a ljca client device
+ *
+ * @type: ljca client type
+ * @id: ljca client id within same client type
+ * @link: ljca client on the same ljca adapter
+ * @auxdev: auxiliary device object
+ * @adapter: ljca adapter the ljca client sit on
+ * @context: the execution context of the event callback
+ * @event_cb: ljca client driver register this callback to get
+ *	firmware asynchronous rx buffer pending notifications
+ * @event_cb_lock: spinlock to protect event callback
+ */
+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 - ljca gpio client device info
+ *
+ * @num: ljca gpio client device pin number
+ * @valid_pin_map: ljca gpio client device valid pin mapping
+ */
+struct ljca_gpio_info {
+	unsigned int num;
+	DECLARE_BITMAP(valid_pin_map, LJCA_MAX_GPIO_NUM);
+};
+
+/**
+ * struct ljca_i2c_info - ljca i2c client device info
+ *
+ * @id: ljca i2c client device identification number
+ * @capacity: ljca i2c client device capacity
+ * @intr_pin: ljca i2c client device interrupt pin number if exists
+ */
+struct ljca_i2c_info {
+	u8 id;
+	u8 capacity;
+	u8 intr_pin;
+};
+
+/**
+ * struct ljca_spi_info - ljca spi client device info
+ *
+ * @id: ljca spi client device identification number
+ * @capacity: ljca spi client device capacity
+ */
+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 u8 *obuf,
+		  unsigned int obuf_len, u8 *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 u8 *obuf,
+			unsigned int obuf_len);
+
+#endif