[PATCH v7 0/6] Add Intel LJCA device driver

[PATCH v7 0/6] Add Intel LJCA device driver

[Ye Xiang]

Add driver for Intel La Jolla Cove Adapter (LJCA) device.
This is a USB-GPIO, USB-I2C and USB-SPI device. We add 4
drivers to support this device: a USB driver, a GPIO chip
driver, a I2C controller driver and a SPI controller driver.

---
v7:
 - ljca: remove unused field `udev` in struct ljca_dev.
 - ljca: rename ljca module name to usb-ljca.
 - ljca: use CONFIG_ACPI to enclose acpi related code.
 - ljca/gpio/i2c/spi: aligh MACRO defination.

v6:
 - ljca: split LJCA USB driver into two commits: USB part and API part.
 - gpio/i2c/spi: use auxiliary bus for sub-module device enumeration instead of MFD.
 - move document patch for LJCA sysfs entry to the 3th patch of this patch series.
 - ljca: fix potential race condition when wait response timeout.
 - ljca: use devm_kzalloc to malloc ljca device struct. 

v5:
 - move ljca.h from drivers/include/mfd to drivers/include/usb.
 - ljca: fix a potential memory leak issue.
 - add a blank line before return to adust to kernel code style.
 - ljca: sysfs: split "cmd" to "ljca_dfu" and "ljca_trace_level".

v4:
 - move ljca.c from drivers/mfd to drivers/usb/misc folder.
 - fix index warning in sysfs-bus-devices-ljca.

v3:
 - spi: make ljca_spi_transfer inline and fix an endian issue.

v2:
 - ljca: remove reset command.
 - gpio/spi/i2c: add `default MFD_LJCA` in Kconfig.
 - gpio: add "select GPIOLIB_IRQCHIP" in Kconfig.

Ye Xiang (6):
  usb: Add support for Intel LJCA device
  usb: ljca: Add transport interfaces for sub-module drivers
  Documentation: Add ABI doc for attributes of LJCA device
  gpio: Add support for Intel LJCA USB GPIO driver
  i2c: Add support for Intel LJCA USB I2C driver
  spi: Add support for Intel LJCA USB SPI driver

 .../ABI/testing/sysfs-bus-usb-devices-ljca    |   36 +
 drivers/gpio/Kconfig                          |   12 +
 drivers/gpio/Makefile                         |    1 +
 drivers/gpio/gpio-ljca.c                      |  458 ++++++++
 drivers/i2c/busses/Kconfig                    |   11 +
 drivers/i2c/busses/Makefile                   |    1 +
 drivers/i2c/busses/i2c-ljca.c                 |  355 ++++++
 drivers/spi/Kconfig                           |   11 +
 drivers/spi/Makefile                          |    1 +
 drivers/spi/spi-ljca.c                        |  289 +++++
 drivers/usb/misc/Kconfig                      |   13 +
 drivers/usb/misc/Makefile                     |    1 +
 drivers/usb/misc/usb-ljca.c                   | 1027 +++++++++++++++++
 include/linux/usb/ljca.h                      |   95 ++
 14 files changed, 2311 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-usb-devices-ljca
 create mode 100644 drivers/gpio/gpio-ljca.c
 create mode 100644 drivers/i2c/busses/i2c-ljca.c
 create mode 100644 drivers/spi/spi-ljca.c
 create mode 100644 drivers/usb/misc/usb-ljca.c
 create mode 100644 include/linux/usb/ljca.h

-- 
2.34.1

[PATCH v7 1/6] usb: Add support for Intel LJCA device

[Ye Xiang]

This patch 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 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: Ye Xiang <xiang.ye@intel.com>
---
 drivers/usb/misc/Kconfig    |  13 +
 drivers/usb/misc/Makefile   |   1 +
 drivers/usb/misc/usb-ljca.c | 966 ++++++++++++++++++++++++++++++++++++
 include/linux/usb/ljca.h    |  43 ++
 4 files changed, 1023 insertions(+)
 create mode 100644 drivers/usb/misc/usb-ljca.c
 create mode 100644 include/linux/usb/ljca.h

diff --git a/drivers/usb/misc/Kconfig b/drivers/usb/misc/Kconfig
index a5f7652db7da..6566039b3e1c 100644
--- a/drivers/usb/misc/Kconfig
+++ b/drivers/usb/misc/Kconfig
@@ -273,6 +273,19 @@ config USB_LINK_LAYER_TEST
 	  Layer Test Device. Say Y only when you want to conduct USB Super Speed
 	  Link Layer Test for host controllers.
 
+config USB_LJCA
+	tristate "Intel La Jolla Cove Adapter support"
+	select AUXILIARY_BUS
+	depends on USB
+	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.
+
 config USB_CHAOSKEY
 	tristate "ChaosKey random number generator driver support"
 	depends on HW_RANDOM
diff --git a/drivers/usb/misc/Makefile b/drivers/usb/misc/Makefile
index 93581baec3a8..a41d02cc4f3e 100644
--- a/drivers/usb/misc/Makefile
+++ b/drivers/usb/misc/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_USB_HUB_USB251XB)		+= usb251xb.o
 obj-$(CONFIG_USB_HSIC_USB3503)		+= usb3503.o
 obj-$(CONFIG_USB_HSIC_USB4604)		+= usb4604.o
 obj-$(CONFIG_USB_CHAOSKEY)		+= chaoskey.o
+obj-$(CONFIG_USB_LJCA)			+= usb-ljca.o
 
 obj-$(CONFIG_USB_SISUSBVGA)		+= sisusbvga/
 obj-$(CONFIG_USB_LINK_LAYER_TEST)	+= lvstest.o
diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
new file mode 100644
index 000000000000..96e2b8c43c58
--- /dev/null
+++ b/drivers/usb/misc/usb-ljca.c
@@ -0,0 +1,966 @@
+// 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>
+
+enum ljca_acpi_match_adr {
+	LJCA_ACPI_MATCH_GPIO,
+	LJCA_ACPI_MATCH_I2C1,
+	LJCA_ACPI_MATCH_I2C2,
+	LJCA_ACPI_MATCH_SPI1,
+	LJCA_ACPI_MATCH_SPI2,
+	LJCA_ACPI_MATCH_MAX,
+};
+
+struct ljca_msg {
+	u8 type;
+	u8 cmd;
+	u8 flags;
+	u8 len;
+	u8 data[];
+} __packed;
+
+struct fw_version {
+	u8 major;
+	u8 minor;
+	__le16 patch;
+	__le16 build;
+} __packed;
+
+/**
+ * enum ljca_stub_type - Stub type supported by LJCA.
+ * @LJCA_MNG_STUB: Provides Management messages.
+ * @LJCA_DIAG_STUB: provides Diagnose messages.
+ * @LJCA_GPIO_STUB: provides GPIO functionality.
+ * @LJCA_I2C_STUB: provides I2C functionality.
+ * @LJCA_SPI_STUB: provides SPI functionality.
+ */
+enum ljca_stub_type {
+	LJCA_MNG_STUB = 1,
+	LJCA_DIAG_STUB,
+	LJCA_GPIO_STUB,
+	LJCA_I2C_STUB,
+	LJCA_SPI_STUB,
+};
+
+/* command Flags */
+#define LJCA_ACK_FLAG	BIT(0)
+#define LJCA_RESP_FLAG	BIT(1)
+#define LJCA_CMPL_FLAG	BIT(2)
+
+/* MNG stub commands */
+enum ljca_mng_cmd {
+	LJCA_MNG_GET_VERSION = 1,
+	LJCA_MNG_RESET_NOTIFY,
+	LJCA_MNG_RESET,
+	LJCA_MNG_ENUM_GPIO,
+	LJCA_MNG_ENUM_I2C,
+	LJCA_MNG_POWER_STATE_CHANGE,
+	LJCA_MNG_SET_DFU_MODE,
+	LJCA_MNG_ENUM_SPI,
+};
+
+/* DIAG commands */
+enum ljca_diag_cmd {
+	LJCA_DIAG_GET_STATE = 1,
+	LJCA_DIAG_GET_STATISTIC,
+	LJCA_DIAG_SET_TRACE_LEVEL,
+	LJCA_DIAG_SET_ECHO_MODE,
+	LJCA_DIAG_GET_FW_LOG,
+	LJCA_DIAG_GET_FW_COREDUMP,
+	LJCA_DIAG_TRIGGER_WDT,
+	LJCA_DIAG_TRIGGER_FAULT,
+	LJCA_DIAG_FEED_WDT,
+	LJCA_DIAG_GET_SECURE_STATE,
+};
+
+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;
+
+#define LJCA_MAX_PACKET_SIZE		64
+#define LJCA_MAX_PAYLOAD_SIZE		(LJCA_MAX_PACKET_SIZE - sizeof(struct ljca_msg))
+#define LJCA_USB_WRITE_TIMEOUT_MS	200
+#define LJCA_USB_WRITE_ACK_TIMEOUT_MS	500
+#define LJCA_USB_ENUM_STUB_TIMEOUT_MS	20
+
+struct ljca_event_cb_entry {
+	ljca_event_cb_t notify;
+	void *context;
+};
+
+struct ljca_dev {
+	struct usb_interface *intf;
+	u8 in_ep; /* the address of the bulk in endpoint */
+	u8 out_ep; /* the address of the bulk out endpoint */
+
+	/* the urb/buffer for read */
+	struct urb *in_urb;
+	unsigned char *ibuf;
+	size_t ibuf_len;
+
+	/* mutex to protect all fields in this structure */
+	struct mutex mutex;
+	bool started;
+	struct list_head stubs_list;
+
+	/* to wait for an ongoing write ack */
+	wait_queue_head_t ack_wq;
+
+	struct auxiliary_device auxdevs[LJCA_ACPI_MATCH_MAX];
+	int auxdev_count;
+};
+
+struct ljca {
+	u8 type;
+	struct ljca_dev *dev;
+};
+
+struct ljca_stub_packet {
+	unsigned int *ibuf_len;
+	u8 *ibuf;
+};
+
+struct ljca_stub {
+	struct list_head list;
+	struct usb_interface *intf;
+	struct ljca_stub_packet ipacket;
+	u8 type;
+
+	/* for identify ack */
+	bool acked;
+	int cur_cmd;
+
+	struct ljca_event_cb_entry event_entry;
+	/* lock to protect event_entry */
+	spinlock_t event_cb_lock;
+
+	struct ljca ljca;
+	unsigned long priv[];
+};
+
+static inline void *ljca_priv(struct ljca_stub *stub)
+{
+	return stub->priv;
+}
+
+static bool ljca_validate(struct ljca_msg *header, u32 data_len)
+{
+	return header->len + sizeof(*header) == data_len;
+}
+
+static struct ljca_stub *ljca_stub_alloc(struct ljca_dev *dev, u8 type, int priv_size)
+{
+	struct ljca_stub *stub;
+
+	stub = kzalloc(struct_size(stub, priv, priv_size), GFP_KERNEL);
+	if (!stub)
+		return ERR_PTR(-ENOMEM);
+
+	stub->type = type;
+	stub->intf = usb_get_intf(dev->intf);
+	stub->ljca.dev = dev;
+	stub->ljca.type = stub->type;
+	spin_lock_init(&stub->event_cb_lock);
+	list_add_tail(&stub->list, &dev->stubs_list);
+
+	return stub;
+}
+
+static void ljca_stub_destroy(struct ljca_stub *stub)
+{
+	usb_put_intf(stub->intf);
+	list_del_init(&stub->list);
+	kfree(stub);
+}
+
+static void ljca_stub_cleanup(struct ljca_dev *dev)
+{
+	struct ljca_stub *stub, *next;
+
+	list_for_each_entry_safe(stub, next, &dev->stubs_list, list) {
+		ljca_stub_destroy(stub);
+	}
+}
+
+static struct ljca_stub *ljca_stub_find(struct ljca_dev *dev, u8 type)
+{
+	struct ljca_stub *stub;
+
+	list_for_each_entry(stub, &dev->stubs_list, list) {
+		if (stub->type == type)
+			return stub;
+	}
+
+	dev_err(&dev->intf->dev, "USB stub not found, type:%d\n", type);
+
+	return ERR_PTR(-ENODEV);
+}
+
+static void ljca_stub_notify(struct ljca_stub *stub, u8 cmd, const void *evt_data, int len)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&stub->event_cb_lock, flags);
+	if (stub->event_entry.notify && stub->event_entry.context)
+		stub->event_entry.notify(stub->event_entry.context, cmd, evt_data, len);
+	spin_unlock_irqrestore(&stub->event_cb_lock, flags);
+}
+
+static int ljca_parse(struct ljca_dev *dev, struct ljca_msg *header)
+{
+	struct ljca_stub *stub;
+
+	stub = ljca_stub_find(dev, header->type);
+	if (IS_ERR(stub))
+		return PTR_ERR(stub);
+
+	if (!(header->flags & LJCA_ACK_FLAG)) {
+		ljca_stub_notify(stub, header->cmd, header->data, header->len);
+		return 0;
+	}
+
+	if (stub->cur_cmd != header->cmd) {
+		dev_err(&dev->intf->dev, "header and stub current command mismatch (%x vs %x)\n",
+			header->cmd, stub->cur_cmd);
+		return -EINVAL;
+	}
+
+	if (stub->ipacket.ibuf && stub->ipacket.ibuf_len) {
+		unsigned int newlen;
+
+		newlen = min_t(unsigned int, header->len, *stub->ipacket.ibuf_len);
+
+		*stub->ipacket.ibuf_len = newlen;
+		memcpy(stub->ipacket.ibuf, header->data, newlen);
+	}
+
+	stub->acked = true;
+	wake_up(&dev->ack_wq);
+
+	return 0;
+}
+
+static int ljca_stub_write(struct ljca_stub *stub, u8 cmd, const void *obuf, unsigned int obuf_len,
+			   void *ibuf, unsigned int *ibuf_len, bool wait_ack, unsigned long timeout)
+{
+	struct ljca_dev *dev = usb_get_intfdata(stub->intf);
+	u8 flags = LJCA_CMPL_FLAG;
+	struct ljca_msg *header;
+	unsigned int msg_len = sizeof(*header) + obuf_len;
+	int actual;
+	int ret;
+
+	if (msg_len > LJCA_MAX_PACKET_SIZE)
+		return -EINVAL;
+
+	if (wait_ack)
+		flags |= LJCA_ACK_FLAG;
+
+	header = kmalloc(msg_len, GFP_KERNEL);
+	if (!header)
+		return -ENOMEM;
+
+	header->type = stub->type;
+	header->cmd = cmd;
+	header->flags = flags;
+	header->len = obuf_len;
+
+	if (obuf)
+		memcpy(header->data, obuf, obuf_len);
+
+	dev_dbg(&dev->intf->dev, "send: type:%d cmd:%d flags:%d len:%d\n", header->type,
+		header->cmd, header->flags, header->len);
+
+	usb_autopm_get_interface(dev->intf);
+	if (!dev->started) {
+		kfree(header);
+		ret = -ENODEV;
+		goto error_put;
+	}
+
+	mutex_lock(&dev->mutex);
+	stub->cur_cmd = cmd;
+	stub->ipacket.ibuf = ibuf;
+	stub->ipacket.ibuf_len = ibuf_len;
+	stub->acked = false;
+	ret = usb_bulk_msg(interface_to_usbdev(dev->intf),
+			   usb_sndbulkpipe(interface_to_usbdev(dev->intf), dev->out_ep), header,
+			   msg_len, &actual, LJCA_USB_WRITE_TIMEOUT_MS);
+	kfree(header);
+	if (ret) {
+		dev_err(&dev->intf->dev, "bridge write failed ret:%d\n", ret);
+		goto error_unlock;
+	}
+
+	if (actual != msg_len) {
+		dev_err(&dev->intf->dev, "bridge write length mismatch (%d vs %d)\n", msg_len,
+			actual);
+		ret = -EINVAL;
+		goto error_unlock;
+	}
+
+	if (wait_ack) {
+		ret = wait_event_timeout(dev->ack_wq, stub->acked, msecs_to_jiffies(timeout));
+		if (!ret) {
+			dev_err(&dev->intf->dev, "acked wait timeout\n");
+			ret = -ETIMEDOUT;
+			goto error_unlock;
+		}
+	}
+
+	ret = 0;
+error_unlock:
+	stub->ipacket.ibuf = NULL;
+	stub->ipacket.ibuf_len = NULL;
+	mutex_unlock(&dev->mutex);
+error_put:
+	usb_autopm_put_interface(dev->intf);
+
+	return ret;
+}
+
+static void ljca_read_complete(struct urb *urb)
+{
+	struct ljca_msg *header = urb->transfer_buffer;
+	struct ljca_dev *dev = urb->context;
+	int len = urb->actual_length;
+	int ret;
+
+	WARN_ON_ONCE(!dev);
+	WARN_ON_ONCE(!header);
+
+	if (urb->status) {
+		/* sync/async unlink faults aren't errors */
+		if (urb->status == -ENOENT || urb->status == -ECONNRESET ||
+		    urb->status == -ESHUTDOWN)
+			return;
+
+		dev_err(&dev->intf->dev, "read bulk urb transfer failed: %d\n", urb->status);
+		goto resubmit;
+	}
+
+	dev_dbg(&dev->intf->dev, "receive: type:%d cmd:%d flags:%d len:%d\n", header->type,
+		header->cmd, header->flags, header->len);
+
+	if (!ljca_validate(header, len)) {
+		dev_err(&dev->intf->dev, "data not correct header->len:%d payload_len:%d\n ",
+			header->len, len);
+		goto resubmit;
+	}
+
+	ret = ljca_parse(dev, header);
+	if (ret)
+		dev_err(&dev->intf->dev, "failed to parse data: ret:%d type:%d len:%d\n", ret,
+			header->type, header->len);
+
+resubmit:
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret)
+		dev_err(&dev->intf->dev, "failed submitting read urb, error %d\n", ret);
+}
+
+static int ljca_start(struct ljca_dev *dev)
+{
+	int ret;
+
+	usb_fill_bulk_urb(dev->in_urb, interface_to_usbdev(dev->intf),
+			  usb_rcvbulkpipe(interface_to_usbdev(dev->intf), dev->in_ep), dev->ibuf,
+			  dev->ibuf_len, ljca_read_complete, dev);
+
+	ret = usb_submit_urb(dev->in_urb, GFP_KERNEL);
+	if (ret) {
+		dev_err(&dev->intf->dev, "failed submitting read urb, error %d\n", ret);
+		return ret;
+	}
+
+	mutex_lock(&dev->mutex);
+	dev->started = true;
+	mutex_unlock(&dev->mutex);
+
+	return 0;
+}
+
+struct ljca_mng_priv {
+	u32 reset_id;
+};
+
+static int ljca_mng_reset_handshake(struct ljca_stub *stub)
+{
+	struct ljca_mng_priv *priv;
+	__le32 reset_id;
+	__le32 reset_id_ret = 0;
+	unsigned int ilen = sizeof(__le32);
+	int ret;
+
+	priv = ljca_priv(stub);
+	reset_id = cpu_to_le32(priv->reset_id++);
+	ret = ljca_stub_write(stub, LJCA_MNG_RESET_NOTIFY, &reset_id, sizeof(reset_id),
+			      &reset_id_ret, &ilen, true, LJCA_USB_WRITE_ACK_TIMEOUT_MS);
+	if (ret)
+		return ret;
+
+	if (ilen != sizeof(reset_id_ret) || reset_id_ret != reset_id) {
+		dev_err(&stub->intf->dev, "mng reset notify failed reset_id:%u/%u\n",
+			le32_to_cpu(reset_id_ret), le32_to_cpu(reset_id));
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void ljca_aux_release(struct device *dev) {}
+
+#ifdef CONFIG_ACPI
+static void ljca_aux_dev_acpi_bind(struct ljca_dev *dev, struct auxiliary_device *auxdev,
+				   unsigned int adr)
+{
+	struct acpi_device *parent;
+	struct acpi_device *adev = NULL;
+
+	/* new auxiliary device bind to acpi device */
+	parent = ACPI_COMPANION(&dev->intf->dev);
+	adev = acpi_find_child_device(parent, adr, false);
+	ACPI_COMPANION_SET(&auxdev->dev, adev ?: parent);
+}
+#else
+static void ljca_aux_dev_acpi_bind(struct ljca_dev *dev, struct auxiliary_device *auxdev,
+				   unsigned int adr)
+{
+}
+#endif
+
+static int ljca_add_aux_dev(struct ljca_dev *dev, char *name, unsigned int id, unsigned int adr,
+			    void *data)
+{
+	struct auxiliary_device *auxdev;
+	int ret;
+
+	if (dev->auxdev_count >= ARRAY_SIZE(dev->auxdevs))
+		return -EINVAL;
+
+	auxdev = &dev->auxdevs[dev->auxdev_count];
+	auxdev->name = name;
+	auxdev->id = id;
+	auxdev->dev.platform_data = data;
+	auxdev->dev.parent = &dev->intf->dev;
+	auxdev->dev.release = ljca_aux_release;
+
+	ret = auxiliary_device_init(auxdev);
+	if (ret)
+		return ret;
+
+	ljca_aux_dev_acpi_bind(dev, auxdev, adr);
+
+	ret = auxiliary_device_add(auxdev);
+	if (ret) {
+		dev_err(&dev->intf->dev, "failed to add auxiliary dev %s.%d\n", name, id);
+		auxiliary_device_uninit(auxdev);
+		return ret;
+	}
+
+	dev->auxdev_count++;
+
+	return 0;
+}
+
+static void ljca_cleanup_aux_dev(struct ljca_dev *dev)
+{
+	int i;
+
+	for (i = 0; i < dev->auxdev_count; i++) {
+		auxiliary_device_delete(&dev->auxdevs[i]);
+		auxiliary_device_uninit(&dev->auxdevs[i]);
+	}
+}
+
+static int ljca_gpio_stub_init(struct ljca_dev *dev, struct ljca_gpio_descriptor *desc)
+{
+	u32 valid_pin[LJCA_MAX_GPIO_NUM / BITS_PER_TYPE(u32)];
+	struct ljca_gpio_info *gpio_info;
+	struct ljca_stub *stub;
+	int gpio_num;
+	int i;
+	int ret;
+
+	gpio_num = desc->pins_per_bank * desc->bank_num;
+	if (gpio_num > LJCA_MAX_GPIO_NUM)
+		return -EINVAL;
+
+	stub = ljca_stub_alloc(dev, LJCA_GPIO_STUB, sizeof(*gpio_info));
+	if (IS_ERR(stub))
+		return PTR_ERR(stub);
+
+	gpio_info = ljca_priv(stub);
+	gpio_info->ljca = &stub->ljca;
+	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_add_aux_dev(dev, "ljca-gpio", 0, LJCA_ACPI_MATCH_GPIO, gpio_info);
+	if (ret)
+		ljca_stub_destroy(stub);
+
+	return ret;
+}
+
+static int ljca_mng_enum_gpio(struct ljca_stub *stub)
+{
+	struct ljca_dev *dev = usb_get_intfdata(stub->intf);
+	char buf[LJCA_MAX_PAYLOAD_SIZE];
+	struct ljca_gpio_descriptor *desc;
+	unsigned int len = LJCA_MAX_PAYLOAD_SIZE;
+	int ret;
+
+	ret = ljca_stub_write(stub, LJCA_MNG_ENUM_GPIO, NULL, 0, buf, &len, true,
+			      LJCA_USB_ENUM_STUB_TIMEOUT_MS);
+	if (ret)
+		return ret;
+
+	desc = (struct ljca_gpio_descriptor *)buf;
+	if (len != struct_size(desc, bank_desc, desc->bank_num)) {
+		dev_err(&stub->intf->dev, "GPIO enumeration failed, len:%u bank_num:%u\n", len,
+			desc->bank_num);
+		return -EINVAL;
+	}
+
+	return ljca_gpio_stub_init(dev, desc);
+}
+
+static int ljca_i2c_stub_init(struct ljca_dev *dev, struct ljca_i2c_descriptor *desc)
+{
+	struct ljca_i2c_info *i2c_info;
+	struct ljca_stub *stub;
+	int ret;
+	int i;
+
+	stub = ljca_stub_alloc(dev, LJCA_I2C_STUB, size_mul(desc->num, sizeof(*i2c_info)));
+	if (IS_ERR(stub))
+		return PTR_ERR(stub);
+
+	i2c_info = ljca_priv(stub);
+
+	for (i = 0; i < desc->num; i++) {
+		i2c_info[i].ljca = &stub->ljca;
+		i2c_info[i].id = desc->info[i].id;
+		i2c_info[i].capacity = desc->info[i].capacity;
+		i2c_info[i].intr_pin = desc->info[i].intr_pin;
+
+		ret = ljca_add_aux_dev(dev, "ljca-i2c", i, LJCA_ACPI_MATCH_I2C1 + i,
+				       &i2c_info[i]);
+		if (ret) {
+			ljca_stub_destroy(stub);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int ljca_mng_enum_i2c(struct ljca_stub *stub)
+{
+	struct ljca_dev *dev = usb_get_intfdata(stub->intf);
+	char buf[LJCA_MAX_PAYLOAD_SIZE];
+	struct ljca_i2c_descriptor *desc;
+	unsigned int len = LJCA_MAX_PAYLOAD_SIZE;
+	int ret;
+
+	ret = ljca_stub_write(stub, LJCA_MNG_ENUM_I2C, NULL, 0, buf, &len, true,
+			      LJCA_USB_ENUM_STUB_TIMEOUT_MS);
+	if (ret) {
+		dev_err(&stub->intf->dev, "I2C enumeration failed, ret:%d len:%u\n", ret, len);
+		return ret;
+	}
+
+	desc = (struct ljca_i2c_descriptor *)buf;
+	return ljca_i2c_stub_init(dev, desc);
+}
+
+static int ljca_spi_stub_init(struct ljca_dev *dev, struct ljca_spi_descriptor *desc)
+{
+	struct ljca_spi_info *spi_info;
+	struct ljca_stub *stub;
+	int i;
+	int ret;
+
+	stub = ljca_stub_alloc(dev, LJCA_SPI_STUB, size_mul(desc->num, sizeof(*spi_info)));
+	if (IS_ERR(stub))
+		return PTR_ERR(stub);
+
+	spi_info = ljca_priv(stub);
+	for (i = 0; i < desc->num; i++) {
+		spi_info[i].ljca = &stub->ljca;
+		spi_info[i].id = desc->info[i].id;
+		spi_info[i].capacity = desc->info[i].capacity;
+
+		ret = ljca_add_aux_dev(dev, "ljca-spi", i, LJCA_ACPI_MATCH_SPI1 + i,
+				       &spi_info[i]);
+		if (ret) {
+			ljca_stub_destroy(stub);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int ljca_mng_enum_spi(struct ljca_stub *stub)
+{
+	struct ljca_dev *dev = usb_get_intfdata(stub->intf);
+	char buf[LJCA_MAX_PAYLOAD_SIZE];
+	struct ljca_spi_descriptor *desc;
+	unsigned int len = LJCA_MAX_PAYLOAD_SIZE;
+	int ret;
+
+	ret = ljca_stub_write(stub, LJCA_MNG_ENUM_SPI, NULL, 0, buf, &len, true,
+			      LJCA_USB_ENUM_STUB_TIMEOUT_MS);
+	if (ret) {
+		dev_err(&stub->intf->dev, "SPI enumeration failed, ret:%d len:%d\n", ret, len);
+		return ret;
+	}
+
+	desc = (struct ljca_spi_descriptor *)buf;
+	return ljca_spi_stub_init(dev, desc);
+}
+
+static int ljca_mng_get_version(struct ljca_stub *stub, char *buf)
+{
+	struct fw_version version = {};
+	unsigned int len = sizeof(version);
+	int ret;
+
+	ret = ljca_stub_write(stub, LJCA_MNG_GET_VERSION, NULL, 0, &version, &len, true,
+			      LJCA_USB_WRITE_ACK_TIMEOUT_MS);
+	if (ret)
+		return ret;
+
+	if (len != sizeof(version)) {
+		dev_err(&stub->intf->dev, "get version failed, len:%d\n", len);
+		return -EINVAL;
+	}
+
+	return sysfs_emit(buf, "%d.%d.%d.%d\n", version.major, version.minor,
+			  le16_to_cpu(version.patch), le16_to_cpu(version.build));
+}
+
+static inline int ljca_mng_set_dfu_mode(struct ljca_stub *stub)
+{
+	return ljca_stub_write(stub, LJCA_MNG_SET_DFU_MODE, NULL, 0, NULL, NULL, true,
+			       LJCA_USB_WRITE_ACK_TIMEOUT_MS);
+}
+
+static int ljca_mng_link(struct ljca_dev *dev, struct ljca_stub *stub)
+{
+	int ret;
+
+	ret = ljca_mng_reset_handshake(stub);
+	if (ret)
+		return ret;
+
+	/* try to enum all the stubs */
+	ret = ljca_mng_enum_gpio(stub);
+	if (ret)
+		dev_warn(&dev->intf->dev, "GPIO function does not support yet\n");
+
+	ret = ljca_mng_enum_i2c(stub);
+	if (ret)
+		dev_warn(&dev->intf->dev, "I2C function does not support yet\n");
+
+	ret = ljca_mng_enum_spi(stub);
+	if (ret)
+		dev_warn(&dev->intf->dev, "SPI function does not support yet\n");
+
+	return 0;
+}
+
+static int ljca_mng_init(struct ljca_dev *dev)
+{
+	struct ljca_stub *stub;
+	struct ljca_mng_priv *priv;
+	int ret;
+
+	stub = ljca_stub_alloc(dev, LJCA_MNG_STUB, sizeof(*priv));
+	if (IS_ERR(stub))
+		return PTR_ERR(stub);
+
+	priv = ljca_priv(stub);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->reset_id = 0;
+
+	ret = ljca_mng_link(dev, stub);
+	if (ret)
+		dev_err(&dev->intf->dev, "mng stub link failed, ret:%d\n", ret);
+
+	return ret;
+}
+
+static inline int ljca_diag_set_trace_level(struct ljca_stub *stub, u8 level)
+{
+	return ljca_stub_write(stub, LJCA_DIAG_SET_TRACE_LEVEL, &level, sizeof(level), NULL, NULL,
+			       true, LJCA_USB_WRITE_ACK_TIMEOUT_MS);
+}
+
+static int ljca_diag_init(struct ljca_dev *dev)
+{
+	struct ljca_stub *stub;
+
+	stub = ljca_stub_alloc(dev, LJCA_DIAG_STUB, 0);
+
+	return PTR_ERR_OR_ZERO(stub);
+}
+
+static void ljca_delete(struct ljca_dev *dev)
+{
+	mutex_destroy(&dev->mutex);
+	usb_free_urb(dev->in_urb);
+	usb_put_intf(dev->intf);
+}
+
+static int ljca_init(struct ljca_dev *dev)
+{
+	mutex_init(&dev->mutex);
+	init_waitqueue_head(&dev->ack_wq);
+	INIT_LIST_HEAD(&dev->stubs_list);
+
+	return 0;
+}
+
+static void ljca_stop(struct ljca_dev *dev)
+{
+	mutex_lock(&dev->mutex);
+	dev->started = false;
+	mutex_unlock(&dev->mutex);
+	usb_kill_urb(dev->in_urb);
+}
+
+static ssize_t ljca_enable_dfu_store(struct device *dev, struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ljca_dev *ljca_dev = usb_get_intfdata(intf);
+	struct ljca_stub *mng_stub = ljca_stub_find(ljca_dev, LJCA_MNG_STUB);
+	bool enable;
+	int ret;
+
+	ret = kstrtobool(buf, &enable);
+	if (ret)
+		return ret;
+
+	if (enable) {
+		ret = ljca_mng_set_dfu_mode(mng_stub);
+		if (ret)
+			return ret;
+	}
+
+	return count;
+}
+static DEVICE_ATTR_WO(ljca_enable_dfu);
+
+static ssize_t ljca_trace_level_store(struct device *dev, struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ljca_dev *ljca_dev = usb_get_intfdata(intf);
+	struct ljca_stub *diag_stub = ljca_stub_find(ljca_dev, LJCA_DIAG_STUB);
+	u8 level;
+	int ret;
+
+	if (kstrtou8(buf, 0, &level))
+		return -EINVAL;
+
+	ret = ljca_diag_set_trace_level(diag_stub, level);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_WO(ljca_trace_level);
+
+static ssize_t ljca_version_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ljca_dev *ljca_dev = usb_get_intfdata(intf);
+	struct ljca_stub *stub = ljca_stub_find(ljca_dev, LJCA_MNG_STUB);
+
+	return ljca_mng_get_version(stub, buf);
+}
+static DEVICE_ATTR_RO(ljca_version);
+
+static struct attribute *ljca_attrs[] = {
+	&dev_attr_ljca_version.attr,
+	&dev_attr_ljca_enable_dfu.attr,
+	&dev_attr_ljca_trace_level.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(ljca);
+
+static int ljca_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	struct ljca_dev *dev;
+	struct usb_endpoint_descriptor *bulk_in, *bulk_out;
+	int ret;
+
+	/* allocate memory for our device state and initialize it */
+	dev = devm_kzalloc(&intf->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	ljca_init(dev);
+	dev->intf = usb_get_intf(intf);
+
+	/* set up the endpoint information use only the first bulk-in and bulk-out endpoints */
+	ret = usb_find_common_endpoints(intf->cur_altsetting, &bulk_in, &bulk_out, NULL, NULL);
+	if (ret) {
+		dev_err(&intf->dev, "could not find both bulk-in and bulk-out endpoints\n");
+		goto error;
+	}
+
+	dev->ibuf_len = usb_endpoint_maxp(bulk_in);
+	dev->in_ep = bulk_in->bEndpointAddress;
+	dev->ibuf = devm_kzalloc(&intf->dev, dev->ibuf_len, GFP_KERNEL);
+	if (!dev->ibuf) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	dev->in_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!dev->in_urb) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	dev->out_ep = bulk_out->bEndpointAddress;
+	/* save our data pointer in this intf device */
+	usb_set_intfdata(intf, dev);
+	ret = ljca_start(dev);
+	if (ret) {
+		dev_err(&intf->dev, "bridge read start failed ret %d\n", ret);
+		goto error;
+	}
+
+	ret = ljca_mng_init(dev);
+	if (ret) {
+		dev_err(&intf->dev, "register mng stub failed ret %d\n", ret);
+		goto error_stop;
+	}
+
+	ret = ljca_diag_init(dev);
+	if (ret) {
+		dev_err(&intf->dev, "register diag stub failed ret %d\n", ret);
+		goto error_stop;
+	}
+
+	usb_enable_autosuspend(interface_to_usbdev(dev->intf));
+
+	return 0;
+
+error_stop:
+	ljca_stop(dev);
+	ljca_cleanup_aux_dev(dev);
+	ljca_stub_cleanup(dev);
+error:
+	dev_err(&intf->dev, "LJCA USB device init failed\n");
+	ljca_delete(dev);
+
+	return ret;
+}
+
+static void ljca_disconnect(struct usb_interface *intf)
+{
+	struct ljca_dev *dev = usb_get_intfdata(intf);
+
+	ljca_stop(dev);
+	ljca_cleanup_aux_dev(dev);
+	ljca_stub_cleanup(dev);
+	ljca_delete(dev);
+}
+
+static int ljca_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct ljca_dev *dev = usb_get_intfdata(intf);
+
+	ljca_stop(dev);
+
+	return 0;
+}
+
+static int ljca_resume(struct usb_interface *intf)
+{
+	struct ljca_dev *dev = usb_get_intfdata(intf);
+
+	return ljca_start(dev);
+}
+
+static const struct usb_device_id ljca_table[] = {
+	{USB_DEVICE(0x8086, 0x0b63)},
+	{}
+};
+MODULE_DEVICE_TABLE(usb, ljca_table);
+
+static struct usb_driver ljca_driver = {
+	.name = "ljca",
+	.probe = ljca_probe,
+	.disconnect = ljca_disconnect,
+	.suspend = ljca_suspend,
+	.resume = ljca_resume,
+	.id_table = ljca_table,
+	.dev_groups = ljca_groups,
+	.supports_autosuspend = 1,
+};
+module_usb_driver(ljca_driver);
+
+MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
+MODULE_AUTHOR("Wang Zhifeng <zhifeng.wang@intel.com>");
+MODULE_AUTHOR("Zhang Lixu <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 000000000000..843d9f79865a
--- /dev/null
+++ b/include/linux/usb/ljca.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _LINUX_USB_LJCA_H_
+#define _LINUX_USB_LJCA_H_
+
+#include <linux/types.h>
+
+struct ljca;
+
+#define LJCA_MAX_GPIO_NUM 64
+struct ljca_gpio_info {
+	struct ljca *ljca;
+	unsigned int num;
+	DECLARE_BITMAP(valid_pin_map, LJCA_MAX_GPIO_NUM);
+};
+
+struct ljca_i2c_info {
+	struct ljca *ljca;
+	u8 id;
+	u8 capacity;
+	u8 intr_pin;
+};
+
+struct ljca_spi_info {
+	struct ljca *ljca;
+	u8 id;
+	u8 capacity;
+};
+
+/**
+ * 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);
+
+#endif
-- 
2.34.1

[PATCH v7 2/6] usb: ljca: Add transport interfaces for sub-module drivers

[Ye Xiang]

This patch adds the transport interfaces for various LJCA
sub-module drivers to communicate with LJCA hardware. The
sub-module 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.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 drivers/usb/misc/usb-ljca.c | 61 +++++++++++++++++++++++++++++++++++++
 include/linux/usb/ljca.h    | 52 +++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+)

diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
index 96e2b8c43c58..a5312869693a 100644
--- a/drivers/usb/misc/usb-ljca.c
+++ b/drivers/usb/misc/usb-ljca.c
@@ -365,6 +365,67 @@ static int ljca_stub_write(struct ljca_stub *stub, u8 cmd, const void *obuf, uns
 	return ret;
 }
 
+static int ljca_transfer_internal(struct ljca *ljca, u8 cmd, const void *obuf,
+				  unsigned int obuf_len, void *ibuf, unsigned int *ibuf_len,
+				  bool wait_ack)
+{
+	struct ljca_stub *stub;
+
+	stub = ljca_stub_find(ljca->dev, ljca->type);
+	if (IS_ERR(stub))
+		return PTR_ERR(stub);
+
+	return ljca_stub_write(stub, cmd, obuf, obuf_len, ibuf, ibuf_len, wait_ack,
+			       LJCA_USB_WRITE_ACK_TIMEOUT_MS);
+}
+
+int ljca_transfer(struct ljca *ljca, u8 cmd, const void *obuf, unsigned int obuf_len, void *ibuf,
+		  unsigned int *ibuf_len)
+{
+	return ljca_transfer_internal(ljca, cmd, obuf, obuf_len, ibuf, ibuf_len, true);
+}
+EXPORT_SYMBOL_NS_GPL(ljca_transfer, LJCA);
+
+int ljca_transfer_noack(struct ljca *ljca, u8 cmd, const void *obuf, unsigned int obuf_len)
+{
+	return ljca_transfer_internal(ljca, cmd, obuf, obuf_len, NULL, NULL, false);
+}
+EXPORT_SYMBOL_NS_GPL(ljca_transfer_noack, LJCA);
+
+int ljca_register_event_cb(struct ljca *ljca, ljca_event_cb_t event_cb, void *context)
+{
+	struct ljca_stub *stub;
+	unsigned long flags;
+
+	stub = ljca_stub_find(ljca->dev, ljca->type);
+	if (IS_ERR(stub))
+		return PTR_ERR(stub);
+
+	spin_lock_irqsave(&stub->event_cb_lock, flags);
+	stub->event_entry.notify = event_cb;
+	stub->event_entry.context = context;
+	spin_unlock_irqrestore(&stub->event_cb_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(ljca_register_event_cb, LJCA);
+
+void ljca_unregister_event_cb(struct ljca *ljca)
+{
+	struct ljca_stub *stub;
+	unsigned long flags;
+
+	stub = ljca_stub_find(ljca->dev, ljca->type);
+	if (IS_ERR(stub))
+		return;
+
+	spin_lock_irqsave(&stub->event_cb_lock, flags);
+	stub->event_entry.notify = NULL;
+	stub->event_entry.context = NULL;
+	spin_unlock_irqrestore(&stub->event_cb_lock, flags);
+}
+EXPORT_SYMBOL_NS_GPL(ljca_unregister_event_cb, LJCA);
+
 static void ljca_read_complete(struct urb *urb)
 {
 	struct ljca_msg *header = urb->transfer_buffer;
diff --git a/include/linux/usb/ljca.h b/include/linux/usb/ljca.h
index 843d9f79865a..9ae3ea242294 100644
--- a/include/linux/usb/ljca.h
+++ b/include/linux/usb/ljca.h
@@ -40,4 +40,56 @@ struct ljca_spi_info {
  */
 typedef void (*ljca_event_cb_t)(void *context, u8 cmd, const void *evt_data, int len);
 
+/**
+ * ljca_register_event_cb - register a callback function to receive events
+ *
+ * @ljca: ljca device handle
+ * @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 *ljca, ljca_event_cb_t event_cb, void *context);
+
+/**
+ * ljca_unregister_event_cb - unregister the callback function for an event
+ *
+ * @ljca: ljca device handle
+ */
+void ljca_unregister_event_cb(struct ljca *ljca);
+
+/**
+ * ljca_transfer - issue a LJCA command and wait for a response and the
+ * associated data
+ *
+ * @ljca: ljca device handle
+ * @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; it will be modified
+ *	to indicate the actual data transferred; it shouldn't be NULL as well
+ *	when ibuf isn't NULL
+ *
+ * Return: 0 for success, negative value for errors
+ */
+int ljca_transfer(struct ljca *ljca, 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
+ *
+ * @ljca: ljca device handle
+ * @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 *ljca, u8 cmd, const void *obuf, unsigned int obuf_len);
+
 #endif
-- 
2.34.1

[PATCH v7 3/6] Documentation: Add ABI doc for attributes of LJCA device

[Ye Xiang]

Add sysfs attributes Documentation entries for LJCA device

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 .../ABI/testing/sysfs-bus-usb-devices-ljca    | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-usb-devices-ljca

diff --git a/Documentation/ABI/testing/sysfs-bus-usb-devices-ljca b/Documentation/ABI/testing/sysfs-bus-usb-devices-ljca
new file mode 100644
index 000000000000..16eecaf870e2
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-usb-devices-ljca
@@ -0,0 +1,36 @@
+What:		/sys/bus/usb/.../ljca_version
+Date:		July 2023
+KernelVersion:	6.4
+Contact:	Ye Xiang <xiang.ye@intel.com>
+Description:
+		Provides the current firmware version of LJCA device.
+		The format is Major.Minor.Patch.Build, where
+		Major, Minor, Patch, and Build are decimal numbers.
+		For example: 1.0.0.256
+
+What:		/sys/bus/usb/.../ljca_enable_dfu
+Date:		July 2023
+KernelVersion:	6.4
+Contact:	Ye Xiang <xiang.ye@intel.com>
+Description:
+		Writing 1 to this file to force the LJCA device into DFU
+		mode so the firmware can be updated. After firmware
+		updating has been done, the device will back to normal
+		working mode.
+
+What:		/sys/bus/usb/.../ljca_trace_level
+Date:		July 2023
+KernelVersion:	6.4
+Contact:	Ye Xiang <xiang.ye@intel.com>
+Description:
+		Writing N to this file to set firmware log level of LJCA
+		device. The log can be printed to another computer through
+		UART ports in LJCA device. Valid values:
+
+		  ==	==========
+		   0	LEVEL_ERROR
+		   1	LEVEL_WARNING
+		   2	LEVEL_INFO
+		   3	LEVEL_DEBUG
+		   4	LEVEL_OFF
+		  ==	==========
-- 
2.34.1

[PATCH v7 4/6] gpio: Add support for Intel LJCA USB GPIO driver

[Ye Xiang]

This patch implements the GPIO function of Intel USB-I2C/GPIO/SPI adapter
device named "La Jolla Cove Adapter" (LJCA). It communicate with LJCA
GPIO module with specific protocol through interfaces exported by LJCA USB
driver.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 drivers/gpio/Kconfig     |  12 +
 drivers/gpio/Makefile    |   1 +
 drivers/gpio/gpio-ljca.c | 458 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 471 insertions(+)
 create mode 100644 drivers/gpio/gpio-ljca.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 13be729710f2..70c57b3ccb22 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1253,6 +1253,18 @@ config GPIO_KEMPLD
 	  This driver can also be built as a module. If so, the module will be
 	  called gpio-kempld.
 
+config GPIO_LJCA
+	tristate "INTEL La Jolla Cove Adapter GPIO support"
+	depends on USB_LJCA
+	select GPIOLIB_IRQCHIP
+	default USB_LJCA
+	help
+	  Select this option to enable GPIO driver for the INTEL
+	  La Jolla Cove Adapter (LJCA) board.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called gpio-ljca.
+
 config GPIO_LP3943
 	tristate "TI/National Semiconductor LP3943 GPIO expander"
 	depends on MFD_LP3943
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index c048ba003367..eb59524d18c0 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_GPIO_IXP4XX)		+= gpio-ixp4xx.o
 obj-$(CONFIG_GPIO_JANZ_TTL)		+= gpio-janz-ttl.o
 obj-$(CONFIG_GPIO_KEMPLD)		+= gpio-kempld.o
 obj-$(CONFIG_GPIO_LATCH)		+= gpio-latch.o
+obj-$(CONFIG_GPIO_LJCA) 		+= gpio-ljca.o
 obj-$(CONFIG_GPIO_LOGICVC)		+= gpio-logicvc.o
 obj-$(CONFIG_GPIO_LOONGSON1)		+= gpio-loongson1.o
 obj-$(CONFIG_GPIO_LOONGSON)		+= gpio-loongson.o
diff --git a/drivers/gpio/gpio-ljca.c b/drivers/gpio/gpio-ljca.c
new file mode 100644
index 000000000000..08ba9b451b05
--- /dev/null
+++ b/drivers/gpio/gpio-ljca.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel La Jolla Cove Adapter USB-GPIO driver
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/dev_printk.h>
+#include <linux/gpio/driver.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/usb/ljca.h>
+
+/* GPIO commands */
+#define LJCA_GPIO_CONFIG		1
+#define LJCA_GPIO_READ			2
+#define LJCA_GPIO_WRITE			3
+#define LJCA_GPIO_INT_EVENT		4
+#define LJCA_GPIO_INT_MASK		5
+#define LJCA_GPIO_INT_UNMASK		6
+
+#define LJCA_GPIO_CONF_DISABLE		BIT(0)
+#define LJCA_GPIO_CONF_INPUT		BIT(1)
+#define LJCA_GPIO_CONF_OUTPUT		BIT(2)
+#define LJCA_GPIO_CONF_PULLUP		BIT(3)
+#define LJCA_GPIO_CONF_PULLDOWN		BIT(4)
+#define LJCA_GPIO_CONF_DEFAULT		BIT(5)
+#define LJCA_GPIO_CONF_INTERRUPT	BIT(6)
+#define LJCA_GPIO_INT_TYPE		BIT(7)
+
+#define LJCA_GPIO_CONF_EDGE		FIELD_PREP(LJCA_GPIO_INT_TYPE, 1)
+#define LJCA_GPIO_CONF_LEVEL		FIELD_PREP(LJCA_GPIO_INT_TYPE, 0)
+
+/* Intentional overlap with PULLUP / PULLDOWN */
+#define LJCA_GPIO_CONF_SET		BIT(3)
+#define LJCA_GPIO_CONF_CLR		BIT(4)
+
+struct gpio_op {
+	u8 index;
+	u8 value;
+} __packed;
+
+struct gpio_packet {
+	u8 num;
+	struct gpio_op item[];
+} __packed;
+
+#define LJCA_GPIO_BUF_SIZE 60
+struct ljca_gpio_dev {
+	struct auxiliary_device *auxdev;
+	struct gpio_chip gc;
+	struct ljca_gpio_info *gpio_info;
+	DECLARE_BITMAP(unmasked_irqs, LJCA_MAX_GPIO_NUM);
+	DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
+	DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
+	u8 *connect_mode;
+	/* mutex to protect irq bus */
+	struct mutex irq_lock;
+	struct work_struct work;
+	/* lock to protect package transfer to Hardware */
+	struct mutex trans_lock;
+
+	u8 obuf[LJCA_GPIO_BUF_SIZE];
+	u8 ibuf[LJCA_GPIO_BUF_SIZE];
+};
+
+static int gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id, u8 config)
+{
+	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
+	int ret;
+
+	mutex_lock(&ljca_gpio->trans_lock);
+	packet->item[0].index = gpio_id;
+	packet->item[0].value = config | ljca_gpio->connect_mode[gpio_id];
+	packet->num = 1;
+
+	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_CONFIG, packet,
+			    struct_size(packet, item, packet->num), NULL, NULL);
+	mutex_unlock(&ljca_gpio->trans_lock);
+	return ret;
+}
+
+static int ljca_gpio_read(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id)
+{
+	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
+	struct gpio_packet *ack_packet = (struct gpio_packet *)ljca_gpio->ibuf;
+	unsigned int ibuf_len = LJCA_GPIO_BUF_SIZE;
+	int ret;
+
+	mutex_lock(&ljca_gpio->trans_lock);
+	packet->num = 1;
+	packet->item[0].index = gpio_id;
+	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_READ, packet,
+			    struct_size(packet, item, packet->num), ljca_gpio->ibuf, &ibuf_len);
+	if (ret)
+		goto out_unlock;
+
+	if (!ibuf_len || ack_packet->num != packet->num) {
+		dev_err(&ljca_gpio->auxdev->dev, "failed gpio_id:%u %u", gpio_id, ack_packet->num);
+		ret = -EIO;
+	}
+
+out_unlock:
+	mutex_unlock(&ljca_gpio->trans_lock);
+	if (ret)
+		return ret;
+	return ack_packet->item[0].value > 0;
+}
+
+static int ljca_gpio_write(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
+			   int value)
+{
+	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
+	int ret;
+
+	mutex_lock(&ljca_gpio->trans_lock);
+	packet->num = 1;
+	packet->item[0].index = gpio_id;
+	packet->item[0].value = value & 1;
+
+	ret = ljca_transfer(ljca_gpio->gpio_info->ljca, LJCA_GPIO_WRITE, packet,
+			    struct_size(packet, item, packet->num), NULL, NULL);
+	mutex_unlock(&ljca_gpio->trans_lock);
+
+	return ret;
+}
+
+static int ljca_gpio_get_value(struct gpio_chip *chip, unsigned int offset)
+{
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
+
+	return ljca_gpio_read(ljca_gpio, offset);
+}
+
+static void ljca_gpio_set_value(struct gpio_chip *chip, unsigned int offset,
+				int val)
+{
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
+	int ret;
+
+	ret = ljca_gpio_write(ljca_gpio, offset, val);
+	if (ret)
+		dev_err(chip->parent, "offset:%u val:%d set value failed %d\n", offset, val, ret);
+}
+
+static int ljca_gpio_direction_input(struct gpio_chip *chip,
+				     unsigned int offset)
+{
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
+	u8 config = LJCA_GPIO_CONF_INPUT | LJCA_GPIO_CONF_CLR;
+
+	return gpio_config(ljca_gpio, offset, config);
+}
+
+static int ljca_gpio_direction_output(struct gpio_chip *chip,
+				      unsigned int offset, int val)
+{
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
+	u8 config = LJCA_GPIO_CONF_OUTPUT | LJCA_GPIO_CONF_CLR;
+	int ret;
+
+	ret = gpio_config(ljca_gpio, offset, config);
+	if (ret)
+		return ret;
+
+	ljca_gpio_set_value(chip, offset, val);
+
+	return 0;
+}
+
+static int ljca_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
+				unsigned long config)
+{
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
+
+	ljca_gpio->connect_mode[offset] = 0;
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_BIAS_PULL_UP:
+		ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLUP;
+		break;
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+		ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLDOWN;
+		break;
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+	case PIN_CONFIG_PERSIST_STATE:
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+static int ljca_gpio_init_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask,
+				     unsigned int ngpios)
+{
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
+
+	WARN_ON_ONCE(ngpios != ljca_gpio->gpio_info->num);
+	bitmap_copy(valid_mask, ljca_gpio->gpio_info->valid_pin_map, ngpios);
+
+	return 0;
+}
+
+static void ljca_gpio_irq_init_valid_mask(struct gpio_chip *chip, unsigned long *valid_mask,
+					  unsigned int ngpios)
+{
+	ljca_gpio_init_valid_mask(chip, valid_mask, ngpios);
+}
+
+static int ljca_enable_irq(struct ljca_gpio_dev *ljca_gpio, int gpio_id, bool enable)
+{
+	struct gpio_packet *packet = (struct gpio_packet *)ljca_gpio->obuf;
+	int ret;
+
+	mutex_lock(&ljca_gpio->trans_lock);
+	packet->num = 1;
+	packet->item[0].index = gpio_id;
+	packet->item[0].value = 0;
+
+	ret = ljca_transfer(ljca_gpio->gpio_info->ljca,
+			    enable ? LJCA_GPIO_INT_UNMASK : LJCA_GPIO_INT_MASK, packet,
+			    struct_size(packet, item, packet->num), NULL, NULL);
+	mutex_unlock(&ljca_gpio->trans_lock);
+
+	return ret;
+}
+
+static void ljca_gpio_async(struct work_struct *work)
+{
+	struct ljca_gpio_dev *ljca_gpio = container_of(work, struct ljca_gpio_dev, work);
+	int gpio_id;
+	int unmasked;
+
+	for_each_set_bit(gpio_id, ljca_gpio->reenable_irqs, ljca_gpio->gc.ngpio) {
+		clear_bit(gpio_id, ljca_gpio->reenable_irqs);
+		unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
+		if (unmasked)
+			ljca_enable_irq(ljca_gpio, gpio_id, true);
+	}
+}
+
+static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data, int len)
+{
+	const struct gpio_packet *packet = evt_data;
+	struct ljca_gpio_dev *ljca_gpio = context;
+	int i;
+	int irq;
+
+	if (cmd != LJCA_GPIO_INT_EVENT)
+		return;
+
+	for (i = 0; i < packet->num; i++) {
+		irq = irq_find_mapping(ljca_gpio->gc.irq.domain, packet->item[i].index);
+		if (!irq) {
+			dev_err(ljca_gpio->gc.parent, "gpio_id %u does not mapped to IRQ yet\n",
+				packet->item[i].index);
+			return;
+		}
+
+		generic_handle_domain_irq(ljca_gpio->gc.irq.domain, irq);
+		set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
+	}
+
+	schedule_work(&ljca_gpio->work);
+}
+
+static void ljca_irq_unmask(struct irq_data *irqd)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
+	int gpio_id = irqd_to_hwirq(irqd);
+
+	gpiochip_enable_irq(gc, gpio_id);
+	set_bit(gpio_id, ljca_gpio->unmasked_irqs);
+}
+
+static void ljca_irq_mask(struct irq_data *irqd)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
+	int gpio_id = irqd_to_hwirq(irqd);
+
+	clear_bit(gpio_id, ljca_gpio->unmasked_irqs);
+	gpiochip_disable_irq(gc, gpio_id);
+}
+
+static int ljca_irq_set_type(struct irq_data *irqd, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
+	int gpio_id = irqd_to_hwirq(irqd);
+
+	ljca_gpio->connect_mode[gpio_id] = LJCA_GPIO_CONF_INTERRUPT;
+	switch (type) {
+	case IRQ_TYPE_LEVEL_HIGH:
+		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLUP);
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLDOWN);
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLUP);
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		ljca_gpio->connect_mode[gpio_id] |= (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLDOWN);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void ljca_irq_bus_lock(struct irq_data *irqd)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
+
+	mutex_lock(&ljca_gpio->irq_lock);
+}
+
+static void ljca_irq_bus_unlock(struct irq_data *irqd)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
+	int gpio_id = irqd_to_hwirq(irqd);
+	int enabled;
+	int unmasked;
+
+	enabled = test_bit(gpio_id, ljca_gpio->enabled_irqs);
+	unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
+
+	if (enabled != unmasked) {
+		if (unmasked) {
+			gpio_config(ljca_gpio, gpio_id, 0);
+			ljca_enable_irq(ljca_gpio, gpio_id, true);
+			set_bit(gpio_id, ljca_gpio->enabled_irqs);
+		} else {
+			ljca_enable_irq(ljca_gpio, gpio_id, false);
+			clear_bit(gpio_id, ljca_gpio->enabled_irqs);
+		}
+	}
+
+	mutex_unlock(&ljca_gpio->irq_lock);
+}
+
+static const struct irq_chip ljca_gpio_irqchip = {
+	.name = "ljca-irq",
+	.irq_mask = ljca_irq_mask,
+	.irq_unmask = ljca_irq_unmask,
+	.irq_set_type = ljca_irq_set_type,
+	.irq_bus_lock = ljca_irq_bus_lock,
+	.irq_bus_sync_unlock = ljca_irq_bus_unlock,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static int ljca_gpio_probe(struct auxiliary_device *auxdev,
+			   const struct auxiliary_device_id *aux_dev_id)
+{
+	struct ljca_gpio_dev *ljca_gpio;
+	struct gpio_irq_chip *girq;
+	int ret;
+
+	ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
+	if (!ljca_gpio)
+		return -ENOMEM;
+
+	ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
+	ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev, ljca_gpio->gpio_info->num,
+					       sizeof(*ljca_gpio->connect_mode), GFP_KERNEL);
+	if (!ljca_gpio->connect_mode)
+		return -ENOMEM;
+
+	mutex_init(&ljca_gpio->irq_lock);
+	mutex_init(&ljca_gpio->trans_lock);
+	ljca_gpio->auxdev = auxdev;
+	ljca_gpio->gc.direction_input = ljca_gpio_direction_input;
+	ljca_gpio->gc.direction_output = ljca_gpio_direction_output;
+	ljca_gpio->gc.get = ljca_gpio_get_value;
+	ljca_gpio->gc.set = ljca_gpio_set_value;
+	ljca_gpio->gc.set_config = ljca_gpio_set_config;
+	ljca_gpio->gc.init_valid_mask = ljca_gpio_init_valid_mask;
+	ljca_gpio->gc.can_sleep = true;
+	ljca_gpio->gc.parent = &auxdev->dev;
+
+	ljca_gpio->gc.base = -1;
+	ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num;
+	ljca_gpio->gc.label = ACPI_COMPANION(&auxdev->dev) ?
+			      acpi_dev_name(ACPI_COMPANION(&auxdev->dev)) :
+			      dev_name(&auxdev->dev);
+	ljca_gpio->gc.owner = THIS_MODULE;
+
+	auxiliary_set_drvdata(auxdev, ljca_gpio);
+	ljca_register_event_cb(ljca_gpio->gpio_info->ljca, ljca_gpio_event_cb, ljca_gpio);
+
+	girq = &ljca_gpio->gc.irq;
+	gpio_irq_chip_set_chip(girq, &ljca_gpio_irqchip);
+	girq->parent_handler = NULL;
+	girq->num_parents = 0;
+	girq->parents = NULL;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_simple_irq;
+	girq->init_valid_mask = ljca_gpio_irq_init_valid_mask;
+
+	INIT_WORK(&ljca_gpio->work, ljca_gpio_async);
+	ret = gpiochip_add_data(&ljca_gpio->gc, ljca_gpio);
+	if (ret) {
+		ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
+		mutex_destroy(&ljca_gpio->irq_lock);
+		mutex_destroy(&ljca_gpio->trans_lock);
+	}
+
+	return ret;
+}
+
+static void ljca_gpio_remove(struct auxiliary_device *auxdev)
+{
+	struct ljca_gpio_dev *ljca_gpio = auxiliary_get_drvdata(auxdev);
+
+	gpiochip_remove(&ljca_gpio->gc);
+	ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
+	cancel_work_sync(&ljca_gpio->work);
+	mutex_destroy(&ljca_gpio->irq_lock);
+	mutex_destroy(&ljca_gpio->trans_lock);
+}
+
+#define LJCA_GPIO_DRV_NAME "ljca.ljca-gpio"
+static const struct auxiliary_device_id ljca_gpio_id_table[] = {
+	{ LJCA_GPIO_DRV_NAME, 0 },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(auxiliary, ljca_gpio_id_table);
+
+static struct auxiliary_driver ljca_gpio_driver = {
+	.probe = ljca_gpio_probe,
+	.remove = ljca_gpio_remove,
+	.id_table = ljca_gpio_id_table,
+};
+module_auxiliary_driver(ljca_gpio_driver);
+
+MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
+MODULE_AUTHOR("Wang Zhifeng <zhifeng.wang@intel.com>");
+MODULE_AUTHOR("Zhang Lixu <lixu.zhang@intel.com>");
+MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-GPIO driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LJCA);
-- 
2.34.1

[PATCH v7 5/6] i2c: Add support for Intel LJCA USB I2C driver

[Ye Xiang]

This patch implements the I2C function of Intel USB-I2C/GPIO/SPI adapter
device named "La Jolla Cove Adapter" (LJCA). It communicate with LJCA
I2c module with specific protocol through interfaces exported by LJCA USB
driver.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 drivers/i2c/busses/Kconfig    |  11 ++
 drivers/i2c/busses/Makefile   |   1 +
 drivers/i2c/busses/i2c-ljca.c | 355 ++++++++++++++++++++++++++++++++++
 3 files changed, 367 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-ljca.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 25eb4e8fd22f..37fed62797a9 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1261,6 +1261,17 @@ config I2C_DLN2
 	 This driver can also be built as a module.  If so, the module
 	 will be called i2c-dln2.
 
+config I2C_LJCA
+	tristate "I2C functionality of Intel La Jolla Cove Adapter"
+	depends on USB_LJCA
+	default USB_LJCA
+	help
+	  If you say yes to this option, I2C functionality support of Intel
+	  La Jolla Cove Adapter (LJCA) will be included.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-ljca.
+
 config I2C_CP2615
 	tristate "Silicon Labs CP2615 USB sound card and I2C adapter"
 	depends on USB
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index af56fe2c75c0..4af5b06ef288 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -133,6 +133,7 @@ obj-$(CONFIG_I2C_GXP)		+= i2c-gxp.o
 # External I2C/SMBus adapter drivers
 obj-$(CONFIG_I2C_DIOLAN_U2C)	+= i2c-diolan-u2c.o
 obj-$(CONFIG_I2C_DLN2)		+= i2c-dln2.o
+obj-$(CONFIG_I2C_LJCA) 		+= i2c-ljca.o
 obj-$(CONFIG_I2C_CP2615) += i2c-cp2615.o
 obj-$(CONFIG_I2C_PARPORT)	+= i2c-parport.o
 obj-$(CONFIG_I2C_PCI1XXXX)	+= i2c-mchp-pci1xxxx.o
diff --git a/drivers/i2c/busses/i2c-ljca.c b/drivers/i2c/busses/i2c-ljca.c
new file mode 100644
index 000000000000..1c96f2be104d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ljca.c
@@ -0,0 +1,355 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel La Jolla Cove Adapter USB-I2C driver
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/dev_printk.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/usb/ljca.h>
+
+/* I2C commands */
+enum ljca_i2c_cmd {
+	LJCA_I2C_INIT = 1,
+	LJCA_I2C_XFER,
+	LJCA_I2C_START,
+	LJCA_I2C_STOP,
+	LJCA_I2C_READ,
+	LJCA_I2C_WRITE,
+};
+
+enum ljca_xfer_type {
+	LJCA_I2C_READ_XFER_TYPE,
+	LJCA_I2C_WRITE_XFER_TYPE,
+};
+
+/* I2C r/w Flags */
+#define LJCA_I2C_SLAVE_TRANSFER_WRITE		0
+#define LJCA_I2C_SLAVE_TRANSFER_READ		1
+
+/* I2C init flags */
+#define LJCA_I2C_INIT_FLAG_MODE			BIT(0)
+#define LJCA_I2C_INIT_FLAG_MODE_POLLING		FIELD_PREP(LJCA_I2C_INIT_FLAG_MODE, 0)
+#define LJCA_I2C_INIT_FLAG_MODE_INTERRUPT	FIELD_PREP(LJCA_I2C_INIT_FLAG_MODE, 1)
+
+#define LJCA_I2C_INIT_FLAG_ADDR_16BIT		BIT(0)
+
+#define LJCA_I2C_INIT_FLAG_FREQ			GENMASK(2, 1)
+#define LJCA_I2C_INIT_FLAG_FREQ_100K		FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 0)
+#define LJCA_I2C_INIT_FLAG_FREQ_400K		FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 1)
+#define LJCA_I2C_INIT_FLAG_FREQ_1M		FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 2)
+
+/* I2C Transfer */
+struct i2c_xfer {
+	u8 id;
+	u8 slave;
+	u16 flag; /* speed, 8/16bit addr, addr increase, etc */
+	u16 addr;
+	u16 len;
+	u8 data[];
+} __packed;
+
+/* I2C raw commands: Init/Start/Read/Write/Stop */
+struct i2c_rw_packet {
+	u8 id;
+	__le16 len;
+	u8 data[];
+} __packed;
+
+#define LJCA_I2C_BUF_SIZE	60
+#define LJCA_I2C_MAX_XFER_SIZE	(LJCA_I2C_BUF_SIZE - sizeof(struct i2c_rw_packet))
+
+struct ljca_i2c_dev {
+	struct auxiliary_device *auxdev;
+	struct ljca_i2c_info *i2c_info;
+	struct i2c_adapter adap;
+
+	u8 obuf[LJCA_I2C_BUF_SIZE];
+	u8 ibuf[LJCA_I2C_BUF_SIZE];
+};
+
+static u8 ljca_i2c_format_slave_addr(u8 slave_addr, u8 type)
+{
+	return (slave_addr << 1) | (type == LJCA_I2C_READ_XFER_TYPE) ?
+		       LJCA_I2C_SLAVE_TRANSFER_READ :
+		       LJCA_I2C_SLAVE_TRANSFER_WRITE;
+}
+
+static int ljca_i2c_init(struct ljca_i2c_dev *ljca_i2c, u8 id)
+{
+	struct i2c_rw_packet *w_packet = (struct i2c_rw_packet *)ljca_i2c->obuf;
+
+	memset(w_packet, 0, sizeof(*w_packet));
+	w_packet->id = id;
+	w_packet->data[0] = LJCA_I2C_INIT_FLAG_FREQ_400K;
+	w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
+
+	return ljca_transfer(ljca_i2c->i2c_info->ljca, LJCA_I2C_INIT, w_packet,
+			     struct_size(w_packet, data, 1), NULL, NULL);
+}
+
+static int ljca_i2c_start(struct ljca_i2c_dev *ljca_i2c, u8 slave_addr, enum ljca_xfer_type type)
+{
+	struct i2c_rw_packet *w_packet = (struct i2c_rw_packet *)ljca_i2c->obuf;
+	struct i2c_rw_packet *r_packet = (struct i2c_rw_packet *)ljca_i2c->ibuf;
+	unsigned int ibuf_len = LJCA_I2C_BUF_SIZE;
+	int ret;
+	s16 rp_len;
+
+	memset(w_packet, 0, sizeof(*w_packet));
+	w_packet->id = ljca_i2c->i2c_info->id;
+	w_packet->data[0] = ljca_i2c_format_slave_addr(slave_addr, type);
+	w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
+
+	ret = ljca_transfer(ljca_i2c->i2c_info->ljca, LJCA_I2C_START, w_packet,
+			    struct_size(w_packet, data, 1), r_packet, &ibuf_len);
+	if (ret)
+		return ret;
+
+	if (ibuf_len < sizeof(*r_packet))
+		return -EIO;
+
+	rp_len = le16_to_cpu(r_packet->len);
+	if (rp_len < 0 || r_packet->id != w_packet->id) {
+		dev_err(&ljca_i2c->adap.dev, "i2c start failed len:%d id:%d %d\n", rp_len,
+			r_packet->id, w_packet->id);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int ljca_i2c_stop(struct ljca_i2c_dev *ljca_i2c, u8 slave_addr)
+{
+	struct i2c_rw_packet *w_packet = (struct i2c_rw_packet *)ljca_i2c->obuf;
+	struct i2c_rw_packet *r_packet = (struct i2c_rw_packet *)ljca_i2c->ibuf;
+	unsigned int ibuf_len = LJCA_I2C_BUF_SIZE;
+	int ret;
+	s16 rp_len;
+
+	memset(w_packet, 0, sizeof(*w_packet));
+	w_packet->id = ljca_i2c->i2c_info->id;
+	w_packet->data[0] = 0;
+	w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
+
+	ret = ljca_transfer(ljca_i2c->i2c_info->ljca, LJCA_I2C_STOP, w_packet,
+			    struct_size(w_packet, data, 1), r_packet, &ibuf_len);
+	if (ret)
+		return ret;
+
+	if (ibuf_len < sizeof(*r_packet))
+		return -EIO;
+
+	rp_len = le16_to_cpu(r_packet->len);
+	if (rp_len < 0 || r_packet->id != w_packet->id) {
+		dev_err(&ljca_i2c->adap.dev, "i2c stop failed len:%d id:%d %d\n", rp_len,
+			r_packet->id, w_packet->id);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int ljca_i2c_pure_read(struct ljca_i2c_dev *ljca_i2c, u8 *data, u8 len)
+{
+	struct i2c_rw_packet *w_packet = (struct i2c_rw_packet *)ljca_i2c->obuf;
+	struct i2c_rw_packet *r_packet = (struct i2c_rw_packet *)ljca_i2c->ibuf;
+	unsigned int ibuf_len = LJCA_I2C_BUF_SIZE;
+	int ret;
+	s16 rp_len;
+
+	if (len > LJCA_I2C_MAX_XFER_SIZE)
+		return -EINVAL;
+
+	memset(w_packet, 0, sizeof(*w_packet));
+	w_packet->id = ljca_i2c->i2c_info->id;
+	w_packet->len = cpu_to_le16(len);
+	w_packet->data[0] = 0;
+
+	ret = ljca_transfer(ljca_i2c->i2c_info->ljca, LJCA_I2C_READ, w_packet,
+			    struct_size(w_packet, data, 1), r_packet, &ibuf_len);
+	if (ret)
+		return ret;
+
+	if (ibuf_len < sizeof(*r_packet))
+		return -EIO;
+
+	rp_len = le16_to_cpu(r_packet->len);
+	if (rp_len != len || r_packet->id != w_packet->id) {
+		dev_err(&ljca_i2c->adap.dev, "i2c raw read failed len:%d id:%d %d\n", rp_len,
+			r_packet->id, w_packet->id);
+		return -EIO;
+	}
+
+	memcpy(data, r_packet->data, len);
+
+	return 0;
+}
+
+static int ljca_i2c_read(struct ljca_i2c_dev *ljca_i2c, u8 slave_addr, u8 *data,
+			 u8 len)
+{
+	int ret;
+
+	ret = ljca_i2c_start(ljca_i2c, slave_addr, LJCA_I2C_READ_XFER_TYPE);
+	if (ret)
+		goto out_stop;
+
+	ret = ljca_i2c_pure_read(ljca_i2c, data, len);
+
+out_stop:
+	ljca_i2c_stop(ljca_i2c, slave_addr);
+
+	return ret;
+}
+
+static int ljca_i2c_pure_write(struct ljca_i2c_dev *ljca_i2c, u8 *data, u8 len)
+{
+	struct i2c_rw_packet *w_packet = (struct i2c_rw_packet *)ljca_i2c->obuf;
+	struct i2c_rw_packet *r_packet = (struct i2c_rw_packet *)ljca_i2c->ibuf;
+	unsigned int ibuf_len = LJCA_I2C_BUF_SIZE;
+	s16 rplen;
+	int ret;
+
+	if (len > LJCA_I2C_MAX_XFER_SIZE)
+		return -EINVAL;
+
+	memset(w_packet, 0, sizeof(*w_packet));
+	w_packet->id = ljca_i2c->i2c_info->id;
+	w_packet->len = cpu_to_le16(len);
+	memcpy(w_packet->data, data, len);
+
+	ret = ljca_transfer(ljca_i2c->i2c_info->ljca, LJCA_I2C_WRITE, w_packet,
+			    struct_size(w_packet, data, len), r_packet, &ibuf_len);
+	if (ret)
+		return ret;
+
+	if (ibuf_len < sizeof(*r_packet))
+		return -EIO;
+
+	rplen = le16_to_cpu(r_packet->len);
+	if (rplen != len || r_packet->id != w_packet->id) {
+		dev_err(&ljca_i2c->adap.dev, "i2c write failed len:%d id:%d/%d\n", rplen,
+			r_packet->id, w_packet->id);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int ljca_i2c_write(struct ljca_i2c_dev *ljca_i2c, u8 slave_addr, u8 *data, u8 len)
+{
+	int ret;
+
+	if (!data)
+		return -EINVAL;
+
+	ret = ljca_i2c_start(ljca_i2c, slave_addr, LJCA_I2C_WRITE_XFER_TYPE);
+	if (ret)
+		goto out_stop;
+
+	ret = ljca_i2c_pure_write(ljca_i2c, data, len);
+
+out_stop:
+	ljca_i2c_stop(ljca_i2c, slave_addr);
+
+	return ret;
+}
+
+static int ljca_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msg, int num)
+{
+	struct ljca_i2c_dev *ljca_i2c;
+	struct i2c_msg *cur_msg;
+	int i, ret;
+
+	ljca_i2c = i2c_get_adapdata(adapter);
+	if (!ljca_i2c)
+		return -EINVAL;
+
+	for (i = 0; i < num; i++) {
+		cur_msg = &msg[i];
+		if (cur_msg->flags & I2C_M_RD)
+			ret = ljca_i2c_read(ljca_i2c, cur_msg->addr, cur_msg->buf, cur_msg->len);
+		else
+			ret = ljca_i2c_write(ljca_i2c, cur_msg->addr, cur_msg->buf, cur_msg->len);
+
+		if (ret)
+			return ret;
+	}
+
+	return num;
+}
+
+static u32 ljca_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_adapter_quirks ljca_i2c_quirks = {
+	.max_read_len = LJCA_I2C_MAX_XFER_SIZE,
+	.max_write_len = LJCA_I2C_MAX_XFER_SIZE,
+};
+
+static const struct i2c_algorithm ljca_i2c_algo = {
+	.master_xfer = ljca_i2c_xfer,
+	.functionality = ljca_i2c_func,
+};
+
+static int ljca_i2c_probe(struct auxiliary_device *auxdev,
+			  const struct auxiliary_device_id *aux_dev_id)
+{
+	struct ljca_i2c_dev *ljca_i2c;
+	int ret;
+
+	ljca_i2c = devm_kzalloc(&auxdev->dev, sizeof(*ljca_i2c), GFP_KERNEL);
+	if (!ljca_i2c)
+		return -ENOMEM;
+
+	ljca_i2c->auxdev = auxdev;
+	ljca_i2c->i2c_info = dev_get_platdata(&auxdev->dev);
+	ljca_i2c->adap.owner = THIS_MODULE;
+	ljca_i2c->adap.class = I2C_CLASS_HWMON;
+	ljca_i2c->adap.algo = &ljca_i2c_algo;
+	ljca_i2c->adap.quirks = &ljca_i2c_quirks;
+	ljca_i2c->adap.dev.parent = &auxdev->dev;
+	device_set_node(&ljca_i2c->adap.dev, dev_fwnode(&auxdev->dev));
+	i2c_set_adapdata(&ljca_i2c->adap, ljca_i2c);
+	snprintf(ljca_i2c->adap.name, sizeof(ljca_i2c->adap.name), "%s-%s-%d",
+		 dev_name(&auxdev->dev), dev_name(auxdev->dev.parent),
+		 ljca_i2c->i2c_info->id);
+
+	auxiliary_set_drvdata(auxdev, ljca_i2c);
+
+	ret = ljca_i2c_init(ljca_i2c, ljca_i2c->i2c_info->id);
+	if (ret) {
+		dev_err(&auxdev->dev, "i2c init failed id:%d\n", ljca_i2c->i2c_info->id);
+		return -EIO;
+	}
+
+	return devm_i2c_add_adapter(&auxdev->dev, &ljca_i2c->adap);
+}
+
+#define LJCA_I2C_DRV_NAME "ljca.ljca-i2c"
+static const struct auxiliary_device_id ljca_i2c_id_table[] = {
+	{ LJCA_I2C_DRV_NAME, 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(auxiliary, ljca_i2c_id_table);
+
+static struct auxiliary_driver ljca_i2c_driver = {
+	.probe = ljca_i2c_probe,
+	.id_table = ljca_i2c_id_table,
+};
+module_auxiliary_driver(ljca_i2c_driver);
+
+MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
+MODULE_AUTHOR("Wang Zhifeng <zhifeng.wang@intel.com>");
+MODULE_AUTHOR("Zhang Lixu <lixu.zhang@intel.com>");
+MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-I2C driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LJCA);
-- 
2.34.1

[PATCH v7 6/6] spi: Add support for Intel LJCA USB SPI driver

[Ye Xiang]

This patch implements the SPI function of Intel USB-I2C/GPIO/SPI adapter
device named "La Jolla Cove Adapter" (LJCA). It communicate with LJCA
SPI module with specific protocol through interfaces exported by LJCA USB
driver.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 drivers/spi/Kconfig    |  11 ++
 drivers/spi/Makefile   |   1 +
 drivers/spi/spi-ljca.c | 289 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 301 insertions(+)
 create mode 100644 drivers/spi/spi-ljca.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 47bbba04fe3a..c3de4e20531f 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -404,6 +404,17 @@ config SPI_HISI_SFC_V3XX
 	  This enables support for HiSilicon v3xx SPI NOR flash controller
 	  found in hi16xx chipsets.
 
+config SPI_LJCA
+	tristate "Intel La Jolla Cove Adapter SPI support"
+	depends on USB_LJCA
+	default USB_LJCA
+	help
+	  Select this option to enable SPI driver for the Intel
+	  La Jolla Cove Adapter (LJCA) board.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called spi-ljca.
+
 config SPI_NXP_FLEXSPI
 	tristate "NXP Flex SPI controller"
 	depends on ARCH_LAYERSCAPE || HAS_IOMEM
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index d87cf75bee6a..0d0cc1b0fb9b 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_SPI_INTEL_PCI)		+= spi-intel-pci.o
 obj-$(CONFIG_SPI_INTEL_PLATFORM)	+= spi-intel-platform.o
 obj-$(CONFIG_SPI_LANTIQ_SSC)		+= spi-lantiq-ssc.o
 obj-$(CONFIG_SPI_JCORE)			+= spi-jcore.o
+obj-$(CONFIG_SPI_LJCA) 			+= spi-ljca.o
 obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
 obj-$(CONFIG_SPI_LP8841_RTC)		+= spi-lp8841-rtc.o
 obj-$(CONFIG_SPI_MESON_SPICC)		+= spi-meson-spicc.o
diff --git a/drivers/spi/spi-ljca.c b/drivers/spi/spi-ljca.c
new file mode 100644
index 000000000000..7db2cb21999e
--- /dev/null
+++ b/drivers/spi/spi-ljca.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel La Jolla Cove Adapter USB-SPI driver
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/dev_printk.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/usb/ljca.h>
+
+/* SPI commands */
+enum ljca_spi_cmd {
+	LJCA_SPI_INIT = 1,
+	LJCA_SPI_READ,
+	LJCA_SPI_WRITE,
+	LJCA_SPI_WRITEREAD,
+	LJCA_SPI_DEINIT,
+};
+
+#define LJCA_SPI_BUS_MAX_HZ 48000000
+enum {
+	LJCA_SPI_BUS_SPEED_24M,
+	LJCA_SPI_BUS_SPEED_12M,
+	LJCA_SPI_BUS_SPEED_8M,
+	LJCA_SPI_BUS_SPEED_6M,
+	LJCA_SPI_BUS_SPEED_4_8M, /*4.8MHz*/
+	LJCA_SPI_BUS_SPEED_MIN = LJCA_SPI_BUS_SPEED_4_8M,
+};
+
+enum {
+	LJCA_SPI_CLOCK_LOW_POLARITY,
+	LJCA_SPI_CLOCK_HIGH_POLARITY,
+};
+
+enum {
+	LJCA_SPI_CLOCK_FIRST_PHASE,
+	LJCA_SPI_CLOCK_SECOND_PHASE,
+};
+
+#define LJCA_SPI_BUF_SIZE		60
+#define LJCA_SPI_MAX_XFER_SIZE		(LJCA_SPI_BUF_SIZE - sizeof(struct spi_xfer_packet))
+
+#define LJCA_SPI_CLK_MODE_POLARITY	BIT(0)
+#define LJCA_SPI_CLK_MODE_PHASE		BIT(1)
+
+#define LJCA_SPI_XFER_INDICATOR_ID	GENMASK(5, 0)
+#define LJCA_SPI_XFER_INDICATOR_CMPL	BIT(6)
+#define LJCA_SPI_XFER_INDICATOR_INDEX	BIT(7)
+
+struct spi_init_packet {
+	u8 index;
+	u8 speed;
+	u8 mode;
+} __packed;
+
+struct spi_xfer_packet {
+	u8 indicator;
+	s8 len;
+	u8 data[];
+} __packed;
+
+struct ljca_spi_dev {
+	struct auxiliary_device *auxdev;
+	struct spi_controller *controller;
+	struct ljca_spi_info *spi_info;
+	u8 speed;
+	u8 mode;
+
+	u8 obuf[LJCA_SPI_BUF_SIZE];
+	u8 ibuf[LJCA_SPI_BUF_SIZE];
+};
+
+static int ljca_spi_read_write(struct ljca_spi_dev *ljca_spi, const u8 *w_data, u8 *r_data, int len,
+			       int id, int complete, int cmd)
+{
+	struct spi_xfer_packet *w_packet = (struct spi_xfer_packet *)ljca_spi->obuf;
+	struct spi_xfer_packet *r_packet = (struct spi_xfer_packet *)ljca_spi->ibuf;
+	unsigned int ibuf_len = LJCA_SPI_BUF_SIZE;
+	int ret;
+
+	w_packet->indicator = FIELD_PREP(LJCA_SPI_XFER_INDICATOR_ID, id) |
+			      FIELD_PREP(LJCA_SPI_XFER_INDICATOR_CMPL, complete) |
+			      FIELD_PREP(LJCA_SPI_XFER_INDICATOR_INDEX,
+					 ljca_spi->spi_info->id);
+
+	if (cmd == LJCA_SPI_READ) {
+		w_packet->len = sizeof(u16);
+		*(__le16 *)&w_packet->data[0] = cpu_to_le16(len);
+	} else {
+		w_packet->len = len;
+		memcpy(w_packet->data, w_data, len);
+	}
+
+	ret = ljca_transfer(ljca_spi->spi_info->ljca, cmd, w_packet,
+			    struct_size(w_packet, data, w_packet->len), r_packet, &ibuf_len);
+	if (ret)
+		return ret;
+
+	if (ibuf_len < sizeof(*r_packet) || r_packet->len <= 0)
+		return -EIO;
+
+	if (r_data)
+		memcpy(r_data, r_packet->data, r_packet->len);
+
+	return 0;
+}
+
+static int ljca_spi_init(struct ljca_spi_dev *ljca_spi, u8 div, u8 mode)
+{
+	struct spi_init_packet w_packet = {};
+	int ret;
+
+	if (ljca_spi->mode == mode && ljca_spi->speed == div)
+		return 0;
+
+	w_packet.mode = FIELD_PREP(LJCA_SPI_CLK_MODE_POLARITY,
+				   (mode & SPI_CPOL) ? LJCA_SPI_CLOCK_HIGH_POLARITY :
+						       LJCA_SPI_CLOCK_LOW_POLARITY) |
+			FIELD_PREP(LJCA_SPI_CLK_MODE_PHASE,
+				   (mode & SPI_CPHA) ? LJCA_SPI_CLOCK_SECOND_PHASE :
+						       LJCA_SPI_CLOCK_FIRST_PHASE);
+
+	w_packet.index = ljca_spi->spi_info->id;
+	w_packet.speed = div;
+	ret = ljca_transfer(ljca_spi->spi_info->ljca, LJCA_SPI_INIT, &w_packet,
+			    sizeof(w_packet), NULL, NULL);
+	if (ret)
+		return ret;
+
+	ljca_spi->mode = mode;
+	ljca_spi->speed = div;
+
+	return 0;
+}
+
+static int ljca_spi_deinit(struct ljca_spi_dev *ljca_spi)
+{
+	struct spi_init_packet w_packet = {};
+
+	w_packet.index = ljca_spi->spi_info->id;
+	return ljca_transfer(ljca_spi->spi_info->ljca, LJCA_SPI_DEINIT, &w_packet, sizeof(w_packet),
+			     NULL, NULL);
+}
+
+static inline int ljca_spi_transfer(struct ljca_spi_dev *ljca_spi, const u8 *tx_data, u8 *rx_data,
+				    u16 len)
+{
+	int remaining = len;
+	int offset = 0;
+	int cur_len;
+	int complete;
+	int i;
+	int cmd;
+	int ret;
+
+	if (tx_data && rx_data)
+		cmd = LJCA_SPI_WRITEREAD;
+	else if (tx_data)
+		cmd = LJCA_SPI_WRITE;
+	else if (rx_data)
+		cmd = LJCA_SPI_READ;
+	else
+		return -EINVAL;
+
+	for (i = 0; remaining > 0; i++) {
+		cur_len = min_t(unsigned int, remaining, LJCA_SPI_MAX_XFER_SIZE);
+		complete = (cur_len == remaining);
+
+		ret = ljca_spi_read_write(ljca_spi,
+					  tx_data ? tx_data + offset : NULL,
+					  rx_data ? rx_data + offset : NULL,
+					  cur_len, i, complete, cmd);
+		if (ret)
+			return ret;
+
+		offset += cur_len;
+		remaining -= cur_len;
+	}
+
+	return 0;
+}
+
+static int ljca_spi_transfer_one(struct spi_controller *controller, struct spi_device *spi,
+				 struct spi_transfer *xfer)
+{
+	struct ljca_spi_dev *ljca_spi = spi_controller_get_devdata(controller);
+	int ret;
+	u8 div;
+
+	div = min_t(u8, LJCA_SPI_BUS_SPEED_MIN,
+		    DIV_ROUND_UP(controller->max_speed_hz, xfer->speed_hz) / 2 - 1);
+	ret = ljca_spi_init(ljca_spi, div, spi->mode);
+	if (ret) {
+		dev_err(&ljca_spi->auxdev->dev, "cannot initialize transfer ret %d\n", ret);
+		return ret;
+	}
+
+	ret = ljca_spi_transfer(ljca_spi, xfer->tx_buf, xfer->rx_buf, xfer->len);
+	if (ret)
+		dev_err(&ljca_spi->auxdev->dev, "ljca spi transfer failed!\n");
+
+	return ret;
+}
+
+static int ljca_spi_probe(struct auxiliary_device *auxdev,
+			  const struct auxiliary_device_id *aux_dev_id)
+{
+	struct spi_controller *controller;
+	struct ljca_spi_dev *ljca_spi;
+	int ret;
+
+	controller = devm_spi_alloc_master(&auxdev->dev, sizeof(*ljca_spi));
+	if (!controller)
+		return -ENOMEM;
+
+	auxiliary_set_drvdata(auxdev, controller);
+	ljca_spi = spi_controller_get_devdata(controller);
+
+	ljca_spi->spi_info = dev_get_platdata(&auxdev->dev);
+	ljca_spi->controller = controller;
+	ljca_spi->auxdev = auxdev;
+	device_set_node(&ljca_spi->controller->dev, dev_fwnode(&auxdev->dev));
+
+	controller->bus_num = -1;
+	controller->mode_bits = SPI_CPHA | SPI_CPOL;
+	controller->transfer_one = ljca_spi_transfer_one;
+	controller->auto_runtime_pm = false;
+	controller->max_speed_hz = LJCA_SPI_BUS_MAX_HZ;
+
+	ret = spi_register_controller(controller);
+	if (ret)
+		dev_err(&auxdev->dev, "Failed to register controller\n");
+
+	return ret;
+}
+
+static void ljca_spi_dev_remove(struct auxiliary_device *auxdev)
+{
+	struct spi_controller *controller = auxiliary_get_drvdata(auxdev);
+	struct ljca_spi_dev *ljca_spi = spi_controller_get_devdata(controller);
+
+	spi_unregister_controller(controller);
+	ljca_spi_deinit(ljca_spi);
+}
+
+static int ljca_spi_dev_suspend(struct device *dev)
+{
+	struct spi_controller *controller = dev_get_drvdata(dev);
+
+	return spi_controller_suspend(controller);
+}
+
+static int ljca_spi_dev_resume(struct device *dev)
+{
+	struct spi_controller *controller = dev_get_drvdata(dev);
+
+	return spi_controller_resume(controller);
+}
+
+static const struct dev_pm_ops ljca_spi_pm = {
+	SYSTEM_SLEEP_PM_OPS(ljca_spi_dev_suspend, ljca_spi_dev_resume)
+};
+
+#define LJCA_SPI_DRV_NAME "ljca.ljca-spi"
+static const struct auxiliary_device_id ljca_spi_id_table[] = {
+	{ LJCA_SPI_DRV_NAME, 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(auxiliary, ljca_spi_id_table);
+
+static struct auxiliary_driver ljca_spi_driver = {
+	.driver.pm	= &ljca_spi_pm,
+	.probe		= ljca_spi_probe,
+	.remove		= ljca_spi_dev_remove,
+	.id_table	= ljca_spi_id_table,
+};
+module_auxiliary_driver(ljca_spi_driver);
+
+MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
+MODULE_AUTHOR("Wang Zhifeng <zhifeng.wang@intel.com>");
+MODULE_AUTHOR("Zhang Lixu <lixu.zhang@intel.com>");
+MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-SPI driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LJCA);
-- 
2.34.1

Re: [PATCH v7 1/6] usb: Add support for Intel LJCA device

[Greg Kroah-Hartman]

On Sat, Mar 25, 2023 at 11:47:06PM +0800, Ye Xiang wrote:
> This patch 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 minimum code in ASL that covers this board is

As this requires ACPI, why are you not saying so in your Kconfig entry?
What good would this driver be without ACPI enabled?

thanks,

greg k-h

Re: [PATCH v7 1/6] usb: Add support for Intel LJCA device

[Ye, Xiang]

Hi Greg,

Thanks for the review.
On Sat, Mar 25, 2023 at 05:20:09PM +0100, Greg Kroah-Hartman wrote:
> On Sat, Mar 25, 2023 at 11:47:06PM +0800, Ye Xiang wrote:
> > This patch 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 minimum code in ASL that covers this board is
> 
> As this requires ACPI, why are you not saying so in your Kconfig entry?
I would add a `depends on ACPI` item on the Kconfig entry so that the
CONFI_ACPI macro can be removed from usb-ljca, because our use case with
LJCA currently needs the ACPI binding.
> What good would this driver be without ACPI enabled?
Before, I just tried to make it compatible with other platforms that
don't support ACPI but want to use LJCA device. But, We don't have
this use case until now.

Thanks
Ye Xiang

Re: [PATCH v7 1/6] usb: Add support for Intel LJCA device

[Greg Kroah-Hartman]

On Sun, Mar 26, 2023 at 01:26:55AM +0800, Ye, Xiang wrote:
> Hi Greg,
> 
> Thanks for the review.
> On Sat, Mar 25, 2023 at 05:20:09PM +0100, Greg Kroah-Hartman wrote:
> > On Sat, Mar 25, 2023 at 11:47:06PM +0800, Ye Xiang wrote:
> > > This patch 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 minimum code in ASL that covers this board is
> > 
> > As this requires ACPI, why are you not saying so in your Kconfig entry?
> I would add a `depends on ACPI` item on the Kconfig entry so that the
> CONFI_ACPI macro can be removed from usb-ljca, because our use case with
> LJCA currently needs the ACPI binding.

That would make more sense.

thanks,

greg k-h

Re: [PATCH v7 1/6] usb: Add support for Intel LJCA device

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 774 bytes --]

On Sun, Mar 26, 2023 at 01:26:55AM +0800, Ye, Xiang wrote:
> On Sat, Mar 25, 2023 at 05:20:09PM +0100, Greg Kroah-Hartman wrote:

> > As this requires ACPI, why are you not saying so in your Kconfig entry?

> I would add a `depends on ACPI` item on the Kconfig entry so that the
> CONFI_ACPI macro can be removed from usb-ljca, because our use case with

> LJCA currently needs the ACPI binding.

> > What good would this driver be without ACPI enabled?
> Before, I just tried to make it compatible with other platforms that
> don't support ACPI but want to use LJCA device. But, We don't have
> this use case until now.

If it builds without ACPI then making the dependency ACPI ||
COMPILE_TEST will help improve build coverage for people doing
treewide or subsystem work.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH v7 1/6] usb: Add support for Intel LJCA device

[Greg Kroah-Hartman]

On Sat, Mar 25, 2023 at 11:47:06PM +0800, Ye Xiang wrote:
> +static void ljca_aux_release(struct device *dev) {}

Sorry, but creating an empty release function just to shut the kernel up
is NOT how to properly do this, you all know better.  This is totally
broken.  The kernel was telling you what you had to do, don't think that
you are being smarter than it by doing this, otherwise we would have
never had the kernel spit out that error in the first place, right?

Now I will ask you to follow the proper Intel kernel review rules and
get proper approval for the patchset before submitting it to us again,
as basic things like this are not supposed to be caught by us, but by
your internal review process first.

good luck!

greg k-h

Re: [PATCH v7 1/6] usb: Add support for Intel LJCA device

[Ye, Xiang]

On Sat, Mar 25, 2023 at 11:27:03PM +0100, Greg Kroah-Hartman wrote:
> On Sat, Mar 25, 2023 at 11:47:06PM +0800, Ye Xiang wrote:
> > +static void ljca_aux_release(struct device *dev) {}
> 
> Sorry, but creating an empty release function just to shut the kernel up
> is NOT how to properly do this, you all know better.  This is totally
> broken.  The kernel was telling you what you had to do, don't think that
> you are being smarter than it by doing this, otherwise we would have
> never had the kernel spit out that error in the first place, right?
Got it. Will use the release callback to free memory used by the auxiliary
device instead.
> 
> Now I will ask you to follow the proper Intel kernel review rules and
> get proper approval for the patchset before submitting it to us again,
> as basic things like this are not supposed to be caught by us, but by
> your internal review process first.
Thanks. I will get approval on Intel's internal review first before sending
the next version out for review.

--
Thanks
Ye Xiang

Re: [PATCH v7 1/6] usb: Add support for Intel LJCA device

[Oliver Neukum]

On 25.03.23 16:47, Ye Xiang wrote:

Hi,

> +static int ljca_parse(struct ljca_dev *dev, struct ljca_msg *header)
> +{
> +	struct ljca_stub *stub;
> +
> +	stub = ljca_stub_find(dev, header->type);
> +	if (IS_ERR(stub))
> +		return PTR_ERR(stub);
> +
> +	if (!(header->flags & LJCA_ACK_FLAG)) {
> +		ljca_stub_notify(stub, header->cmd, header->data, header->len);
> +		return 0;
> +	}
> +
> +	if (stub->cur_cmd != header->cmd) {
> +		dev_err(&dev->intf->dev, "header and stub current command mismatch (%x vs %x)\n",
> +			header->cmd, stub->cur_cmd);
> +		return -EINVAL;
> +	}
> +
> +	if (stub->ipacket.ibuf && stub->ipacket.ibuf_len) {

Here you read those values from ipacket.

> +		unsigned int newlen;
> +
> +		newlen = min_t(unsigned int, header->len, *stub->ipacket.ibuf_len);

Here you read them again.

> +
> +		*stub->ipacket.ibuf_len = newlen;
> +		memcpy(stub->ipacket.ibuf, header->data, newlen);

And here you read them again. The compiler is free to generate a memory access for
ipacket.ibuf, which may read a new value from RAM. That means here you have a window
in which you can no longer guarantee stub->ipacket.ibuf != NULL,
if you set it to NULL elsewhere.

> +	}
> +
> +	stub->acked = true;
> +	wake_up(&dev->ack_wq);
> +
> +	return 0;
> +}
> +
> +static int ljca_stub_write(struct ljca_stub *stub, u8 cmd, const void *obuf, unsigned int obuf_len,
> +			   void *ibuf, unsigned int *ibuf_len, bool wait_ack, unsigned long timeout)
> +{
> +	struct ljca_dev *dev = usb_get_intfdata(stub->intf);
> +	u8 flags = LJCA_CMPL_FLAG;
> +	struct ljca_msg *header;
> +	unsigned int msg_len = sizeof(*header) + obuf_len;
> +	int actual;
> +	int ret;
> +
> +	if (msg_len > LJCA_MAX_PACKET_SIZE)
> +		return -EINVAL;
> +
> +	if (wait_ack)
> +		flags |= LJCA_ACK_FLAG;
> +
> +	header = kmalloc(msg_len, GFP_KERNEL);
> +	if (!header)
> +		return -ENOMEM;
> +
> +	header->type = stub->type;
> +	header->cmd = cmd;
> +	header->flags = flags;
> +	header->len = obuf_len;
> +
> +	if (obuf)
> +		memcpy(header->data, obuf, obuf_len);
> +
> +	dev_dbg(&dev->intf->dev, "send: type:%d cmd:%d flags:%d len:%d\n", header->type,
> +		header->cmd, header->flags, header->len);
> +
> +	usb_autopm_get_interface(dev->intf);
> +	if (!dev->started) {
> +		kfree(header);
> +		ret = -ENODEV;
> +		goto error_put;
> +	}
> +
> +	mutex_lock(&dev->mutex);
> +	stub->cur_cmd = cmd;
> +	stub->ipacket.ibuf = ibuf;
> +	stub->ipacket.ibuf_len = ibuf_len;
> +	stub->acked = false;
> +	ret = usb_bulk_msg(interface_to_usbdev(dev->intf),
> +			   usb_sndbulkpipe(interface_to_usbdev(dev->intf), dev->out_ep), header,
> +			   msg_len, &actual, LJCA_USB_WRITE_TIMEOUT_MS);
> +	kfree(header);
> +	if (ret) {
> +		dev_err(&dev->intf->dev, "bridge write failed ret:%d\n", ret);
> +		goto error_unlock;
> +	}
> +
> +	if (actual != msg_len) {
> +		dev_err(&dev->intf->dev, "bridge write length mismatch (%d vs %d)\n", msg_len,
> +			actual);
> +		ret = -EINVAL;
> +		goto error_unlock;
> +	}
> +
> +	if (wait_ack) {
> +		ret = wait_event_timeout(dev->ack_wq, stub->acked, msecs_to_jiffies(timeout));
> +		if (!ret) {
> +			dev_err(&dev->intf->dev, "acked wait timeout\n");
> +			ret = -ETIMEDOUT;
> +			goto error_unlock;
> +		}
> +	}
> +
> +	ret = 0;
> +error_unlock:
> +	stub->ipacket.ibuf = NULL;
> +	stub->ipacket.ibuf_len = NULL;

And here you set stub->ipacket.ibuf to NULL.
If you do that and want consistency, you'll need to use READ_ONCE
and a local variable if you read this in interrupt.

> +	mutex_unlock(&dev->mutex);
> +error_put:
> +	usb_autopm_put_interface(dev->intf);
> +
> +	return ret;
> +}
> +

	HTH,
		Oliver

Re: [PATCH v7 4/6] gpio: Add support for Intel LJCA USB GPIO driver

[Linus Walleij]

Hi Ye,

thanks for your patch!

On Sat, Mar 25, 2023 at 4:48 PM Ye Xiang <xiang.ye@intel.com> wrote:

> This patch implements the GPIO function of Intel USB-I2C/GPIO/SPI adapter
> device named "La Jolla Cove Adapter" (LJCA). It communicate with LJCA
> GPIO module with specific protocol through interfaces exported by LJCA USB
> driver.
>
> Signed-off-by: Ye Xiang <xiang.ye@intel.com>

Lots of improvements! here are some comments:

> @@ -1253,6 +1253,18 @@ config GPIO_KEMPLD
>           This driver can also be built as a module. If so, the module will be
>           called gpio-kempld.
>
> +config GPIO_LJCA
> +       tristate "INTEL La Jolla Cove Adapter GPIO support"
> +       depends on USB_LJCA
> +       select GPIOLIB_IRQCHIP
> +       default USB_LJCA
> +       help
> +         Select this option to enable GPIO driver for the INTEL
> +         La Jolla Cove Adapter (LJCA) board.
> +
> +         This driver can also be built as a module. If so, the module
> +         will be called gpio-ljca.

The GPIO Kconfig has a separate submenu for USB expanders, so
put this Kconfig in that submenu. This makes the choice come in
a more logical spot and not appear on configs that don't even
have USB.

(...)
> +       DECLARE_BITMAP(unmasked_irqs, LJCA_MAX_GPIO_NUM);
> +       DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
> +       DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
> +       u8 *connect_mode;
> +       /* mutex to protect irq bus */
> +       struct mutex irq_lock;
(...)

With IRQ code like this from a USB callback:

> +static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data, int len)
> +{
> +       const struct gpio_packet *packet = evt_data;
> +       struct ljca_gpio_dev *ljca_gpio = context;
> +       int i;
> +       int irq;
> +
> +       if (cmd != LJCA_GPIO_INT_EVENT)
> +               return;
> +
> +       for (i = 0; i < packet->num; i++) {
> +               irq = irq_find_mapping(ljca_gpio->gc.irq.domain, packet->item[i].index);
> +               if (!irq) {
> +                       dev_err(ljca_gpio->gc.parent, "gpio_id %u does not mapped to IRQ yet\n",
> +                               packet->item[i].index);
> +                       return;
> +               }
> +
> +               generic_handle_domain_irq(ljca_gpio->gc.irq.domain, irq);
> +               set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
> +       }
> +
> +       schedule_work(&ljca_gpio->work);
> +}

I don't feel comfortable merging this unless Marc Zyngier has looked at the
code first, so please CC him on this patch next time.

> +static const struct irq_chip ljca_gpio_irqchip = {
> +       .name = "ljca-irq",
> +       .irq_mask = ljca_irq_mask,
> +       .irq_unmask = ljca_irq_unmask,
> +       .irq_set_type = ljca_irq_set_type,
> +       .irq_bus_lock = ljca_irq_bus_lock,
> +       .irq_bus_sync_unlock = ljca_irq_bus_unlock,
> +       .flags = IRQCHIP_IMMUTABLE,
> +       GPIOCHIP_IRQ_RESOURCE_HELPERS,
> +};

Thanks for fixing the immutable irq chip!

> +       ljca_gpio->auxdev = auxdev;
> +       ljca_gpio->gc.direction_input = ljca_gpio_direction_input;
> +       ljca_gpio->gc.direction_output = ljca_gpio_direction_output;

Can you implement .get_direction()?

It's scanned on probe to determine the initial state of each
line so it is very nice to have.

Yours,
Linus Walleij

Re: [PATCH v7 3/6] Documentation: Add ABI doc for attributes of LJCA device

[Oliver Neukum]

On 25.03.23 16:47, Ye Xiang wrote:
> Add sysfs attributes Documentation entries for LJCA device

Hi,

do we really want each driver to have its own attribute for that?
It seems to me that that should be unified.

	Regards
		Oliver

> +
> +What:		/sys/bus/usb/.../ljca_enable_dfu
> +Date:		July 2023
> +KernelVersion:	6.4
> +Contact:	Ye Xiang<xiang.ye@intel.com>
> +Description:
> +		Writing 1 to this file to force the LJCA device into DFU
> +		mode so the firmware can be updated. After firmware
> +		updating has been done, the device will back to normal
> +		working mode.

Re: [PATCH v7 3/6] Documentation: Add ABI doc for attributes of LJCA device

[Ye, Xiang]

Hi Oliver

Thanks for the review.
On Tue, Apr 04, 2023 at 10:53:48AM +0200, Oliver Neukum wrote:
> 
> 
> On 25.03.23 16:47, Ye Xiang wrote:
> > Add sysfs attributes Documentation entries for LJCA device
> 
> Hi,
> 
> do we really want each driver to have its own attribute for that?
> It seems to me that that should be unified.
Three ABI entries are added in this patch: ljca_version, ljca_trace_level,
and ljca_enable_dfu. The first two items are specified for LJCA device and
I think they can be kept in sysfs-bus-usb-devices-ljca.

But for ljca_enable_dfu, I didn't see a unified DFU entry in sys-bus-usb.
I am not sure whether other USB devices have similar DFU mode or not.

Any suggestions?

Thanks
Ye Xiang
> 
> > +
> > +What:		/sys/bus/usb/.../ljca_enable_dfu
> > +Date:		July 2023
> > +KernelVersion:	6.4
> > +Contact:	Ye Xiang<xiang.ye@intel.com>
> > +Description:
> > +		Writing 1 to this file to force the LJCA device into DFU
> > +		mode so the firmware can be updated. After firmware
> > +		updating has been done, the device will back to normal
> > +		working mode.

Re: [PATCH v7 3/6] Documentation: Add ABI doc for attributes of LJCA device

[Oliver Neukum]

On 10.04.23 12:44, Ye, Xiang wrote:

Hi,

>> do we really want each driver to have its own attribute for that?
>> It seems to me that that should be unified.
> Three ABI entries are added in this patch: ljca_version, ljca_trace_level,
> and ljca_enable_dfu. The first two items are specified for LJCA device and
> I think they can be kept in sysfs-bus-usb-devices-ljca.
> 
> But for ljca_enable_dfu, I didn't see a unified DFU entry in sys-bus-usb.
> I am not sure whether other USB devices have similar DFU mode or not.
> 
> Any suggestions?

What exactly does this attribute do?
Is it in addition to the normal DFU_DETACH + reset sequence, is it
needed for DFU_DETACH to work, does it enable the
DFU class interface descriptor?

A point of DFU is rather that the capability should be announced
via descriptors. The answer would depend on what exactly this
attribute does.

	Regards
		Oliver