[PATCH v2 0/5] Add Intel LJCA device driver

[PATCH v2 0/5] 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.

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

Ye Xiang (5):
  mfd: Add support for Intel 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
  Documentation: Add ABI doc for attributes of LJCA device

 .../ABI/testing/sysfs-bus-usb-devices-ljca    |  22 +
 drivers/gpio/Kconfig                          |  12 +
 drivers/gpio/Makefile                         |   1 +
 drivers/gpio/gpio-ljca.c                      | 454 ++++++++
 drivers/i2c/busses/Kconfig                    |  11 +
 drivers/i2c/busses/Makefile                   |   1 +
 drivers/i2c/busses/i2c-ljca.c                 | 357 +++++++
 drivers/mfd/Kconfig                           |  13 +
 drivers/mfd/Makefile                          |   1 +
 drivers/mfd/ljca.c                            | 969 ++++++++++++++++++
 drivers/spi/Kconfig                           |  11 +
 drivers/spi/Makefile                          |   1 +
 drivers/spi/spi-ljca.c                        | 291 ++++++
 include/linux/mfd/ljca.h                      |  95 ++
 14 files changed, 2239 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/mfd/ljca.c
 create mode 100644 drivers/spi/spi-ljca.c
 create mode 100644 include/linux/mfd/ljca.h

-- 
2.34.1

[PATCH v2 1/5] mfd: 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. The sub-module of
LJCA can use ljca_transfer() to issue a transfer between host
and hardware.

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/mfd/Kconfig      |  13 +
 drivers/mfd/Makefile     |   1 +
 drivers/mfd/ljca.c       | 969 +++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/ljca.h |  95 ++++
 4 files changed, 1078 insertions(+)
 create mode 100644 drivers/mfd/ljca.c
 create mode 100644 include/linux/mfd/ljca.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 30db49f31866..f74df74d7f30 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -411,6 +411,19 @@ config MFD_DLN2
 	  etc. must be enabled in order to use the functionality of
 	  the device.
 
+config MFD_LJCA
+	tristate "Intel La Jolla Cove Adapter support"
+	select MFD_CORE
+	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 ljca.
+
 config MFD_ENE_KB3930
 	tristate "ENE KB3930 Embedded Controller support"
 	depends on I2C
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 457471478a93..b1831cf4d6ed 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -237,6 +237,7 @@ obj-$(CONFIG_MFD_HI6421_PMIC)	+= hi6421-pmic-core.o
 obj-$(CONFIG_MFD_HI6421_SPMI)	+= hi6421-spmi-pmic.o
 obj-$(CONFIG_MFD_HI655X_PMIC)   += hi655x-pmic.o
 obj-$(CONFIG_MFD_DLN2)		+= dln2.o
+obj-$(CONFIG_MFD_LJCA) 		+= ljca.o
 obj-$(CONFIG_MFD_RT4831)	+= rt4831.o
 obj-$(CONFIG_MFD_RT5033)	+= rt5033.o
 obj-$(CONFIG_MFD_RT5120)	+= rt5120.o
diff --git a/drivers/mfd/ljca.c b/drivers/mfd/ljca.c
new file mode 100644
index 000000000000..e9520f3d2904
--- /dev/null
+++ b/drivers/mfd/ljca.c
@@ -0,0 +1,969 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel La Jolla Cove Adapter USB driver
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#include <linux/dev_printk.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/ljca.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/usb.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,
+};
+
+static struct mfd_cell_acpi_match ljca_acpi_match_gpio = {
+	.adr = LJCA_ACPI_MATCH_GPIO,
+};
+
+static struct mfd_cell_acpi_match ljca_acpi_match_i2cs[] = {
+	{
+		.adr = LJCA_ACPI_MATCH_I2C1,
+	},
+	{
+		.adr = LJCA_ACPI_MATCH_I2C2,
+	},
+};
+
+static struct mfd_cell_acpi_match ljca_acpi_match_spis[] = {
+	{
+		.adr = LJCA_ACPI_MATCH_SPI1,
+	},
+	{
+		.adr = LJCA_ACPI_MATCH_SPI2,
+	},
+};
+
+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_device *udev;
+	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;
+
+	bool started;
+	struct list_head stubs_list;
+
+	/* to wait for an ongoing write ack */
+	wait_queue_head_t ack_wq;
+
+	struct mfd_cell *cells;
+	int cell_count;
+	/* mutex to protect package transfer with LJCA device */
+	struct mutex mutex;
+};
+
+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 = 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 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) {
+		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(dev->udev, usb_sndbulkpipe(dev->udev, 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;
+		}
+	}
+
+	stub->ipacket.ibuf = NULL;
+	stub->ipacket.ibuf_len = NULL;
+	ret = 0;
+error_unlock:
+	mutex_unlock(&dev->mutex);
+error_put:
+	usb_autopm_put_interface(dev->intf);
+	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_stub_cleanup(struct ljca_dev *dev)
+{
+	struct ljca_stub *stub, *next;
+
+	list_for_each_entry_safe(stub, next, &dev->stubs_list, list) {
+		list_del_init(&stub->list);
+		kfree(stub);
+	}
+}
+
+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, dev->udev, usb_rcvbulkpipe(dev->udev, 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);
+
+	dev->started = true;
+	return ret;
+}
+
+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 int ljca_add_mfd_cell(struct ljca_dev *dev, struct mfd_cell *cell)
+{
+	struct mfd_cell *new_cells;
+
+	new_cells = krealloc_array(dev->cells, dev->cell_count + 1, sizeof(*new_cells), GFP_KERNEL);
+	if (!new_cells)
+		return -ENOMEM;
+
+	memcpy(&new_cells[dev->cell_count], cell, sizeof(*cell));
+	dev->cells = new_cells;
+	dev->cell_count++;
+
+	return 0;
+}
+
+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 mfd_cell cell = {};
+	struct ljca_stub *stub;
+	int gpio_num;
+	int i;
+
+	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);
+
+	cell.name = "ljca-gpio";
+	cell.platform_data = gpio_info;
+	cell.pdata_size = sizeof(*gpio_info);
+	cell.acpi_match = &ljca_acpi_match_gpio;
+
+	return ljca_add_mfd_cell(dev, &cell);
+}
+
+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++) {
+		struct mfd_cell cell = {};
+
+		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;
+
+		cell.name = "ljca-i2c";
+		cell.platform_data = &i2c_info[i];
+		cell.pdata_size = sizeof(i2c_info[i]);
+
+		if (i < ARRAY_SIZE(ljca_acpi_match_i2cs))
+			cell.acpi_match = &ljca_acpi_match_i2cs[i];
+
+		ret = ljca_add_mfd_cell(dev, &cell);
+		if (ret)
+			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++) {
+		struct mfd_cell cell = {};
+
+		spi_info[i].ljca = &stub->ljca;
+		spi_info[i].id = desc->info[i].id;
+		spi_info[i].capacity = desc->info[i].capacity;
+
+		cell.name = "ljca-spi";
+		cell.platform_data = &spi_info[i];
+		cell.pdata_size = sizeof(spi_info[i]);
+		if (i < ARRAY_SIZE(ljca_acpi_match_spis))
+			cell.acpi_match = &ljca_acpi_match_spis[i];
+
+		ret = ljca_add_mfd_cell(dev, &cell);
+		if (ret)
+			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 */
+	ljca_mng_enum_gpio(stub);
+	ljca_mng_enum_i2c(stub);
+	ljca_mng_enum_spi(stub);
+
+	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);
+	usb_put_dev(dev->udev);
+	kfree(dev->ibuf);
+	kfree(dev->cells);
+	kfree(dev);
+}
+
+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)
+{
+	dev->started = false;
+	usb_kill_urb(dev->in_urb);
+}
+
+static ssize_t cmd_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);
+	struct ljca_stub *diag_stub = ljca_stub_find(ljca_dev, LJCA_DIAG_STUB);
+
+	if (sysfs_streq(buf, "dfu"))
+		ljca_mng_set_dfu_mode(mng_stub);
+	else if (sysfs_streq(buf, "debug"))
+		ljca_diag_set_trace_level(diag_stub, 3);
+
+	return count;
+}
+
+static ssize_t cmd_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%s\n", "supported cmd: [dfu, debug]");
+}
+static DEVICE_ATTR_RW(cmd);
+
+static ssize_t 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(version);
+
+static struct attribute *ljca_attrs[] = {
+	&dev_attr_version.attr,
+	&dev_attr_cmd.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 = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	ljca_init(dev);
+	dev->udev = usb_get_dev(interface_to_usbdev(intf));
+	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 = kzalloc(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;
+	}
+
+	ret = mfd_add_hotplug_devices(&intf->dev, dev->cells, dev->cell_count);
+	if (ret) {
+		dev_err(&intf->dev, "failed to add mfd devices\n");
+		goto error_stop;
+	}
+
+	usb_enable_autosuspend(dev->udev);
+	return 0;
+error_stop:
+	ljca_stop(dev);
+error:
+	dev_err(&intf->dev, "LJCA USB device init failed\n");
+	/* this frees allocated memory */
+	ljca_stub_cleanup(dev);
+	ljca_delete(dev);
+	return ret;
+}
+
+static void ljca_disconnect(struct usb_interface *intf)
+{
+	struct ljca_dev *dev = usb_get_intfdata(intf);
+
+	ljca_stop(dev);
+	mfd_remove_devices(&intf->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/mfd/ljca.h b/include/linux/mfd/ljca.h
new file mode 100644
index 000000000000..9ae3ea242294
--- /dev/null
+++ b/include/linux/mfd/ljca.h
@@ -0,0 +1,95 @@
+/* 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);
+
+/**
+ * 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 v2 2/5] 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 | 454 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 467 insertions(+)
 create mode 100644 drivers/gpio/gpio-ljca.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e9917a45b005..8332af1f5025 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1257,6 +1257,18 @@ 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 MFD_LJCA
+	select GPIOLIB_IRQCHIP
+	default MFD_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 010587025fc8..4e2e2d44b820 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -78,6 +78,7 @@ 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..87863f0230f5
--- /dev/null
+++ b/drivers/gpio/gpio-ljca.c
@@ -0,0 +1,454 @@
+// 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/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/mfd/ljca.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.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 platform_device *pdev;
+	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->pdev->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 platform_device *pdev)
+{
+	struct ljca_gpio_dev *ljca_gpio;
+	struct gpio_irq_chip *girq;
+	int ret;
+
+	ljca_gpio = devm_kzalloc(&pdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
+	if (!ljca_gpio)
+		return -ENOMEM;
+
+	ljca_gpio->gpio_info = dev_get_platdata(&pdev->dev);
+	ljca_gpio->connect_mode = devm_kcalloc(&pdev->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->pdev = pdev;
+	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 = &pdev->dev;
+
+	ljca_gpio->gc.base = -1;
+	ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num;
+	ljca_gpio->gc.label = ACPI_COMPANION(&pdev->dev) ?
+			      acpi_dev_name(ACPI_COMPANION(&pdev->dev)) :
+			      dev_name(&pdev->dev);
+	ljca_gpio->gc.owner = THIS_MODULE;
+
+	platform_set_drvdata(pdev, 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 int ljca_gpio_remove(struct platform_device *pdev)
+{
+	struct ljca_gpio_dev *ljca_gpio = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&ljca_gpio->gc);
+	ljca_unregister_event_cb(ljca_gpio->gpio_info->ljca);
+	mutex_destroy(&ljca_gpio->irq_lock);
+	mutex_destroy(&ljca_gpio->trans_lock);
+	return 0;
+}
+
+#define LJCA_GPIO_DRV_NAME "ljca-gpio"
+static const struct platform_device_id ljca_gpio_id[] = {
+	{ LJCA_GPIO_DRV_NAME, 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, ljca_gpio_id);
+
+static struct platform_driver ljca_gpio_driver = {
+	.driver.name = LJCA_GPIO_DRV_NAME,
+	.probe = ljca_gpio_probe,
+	.remove = ljca_gpio_remove,
+};
+module_platform_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 v2 3/5] 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 | 357 ++++++++++++++++++++++++++++++++++
 3 files changed, 369 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-ljca.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index a7bfddf08fa7..f94e2ed32563 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1243,6 +1243,17 @@ 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 MFD_LJCA
+	default MFD_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 e73cdb1d2b5a..66a1fe79d0f6 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -131,6 +131,7 @@ obj-$(CONFIG_I2C_RCAR)		+= i2c-rcar.o
 # External I2C/SMBus adapter drivers
 obj-$(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..3250297c15b8
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ljca.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel La Jolla Cove Adapter USB-I2C driver
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/dev_printk.h>
+#include <linux/i2c.h>
+#include <linux/mfd/ljca.h>
+#include <linux/module.h>
+#include <linux/platform_device.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 platform_device *pdev;
+	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 platform_device *pdev)
+{
+	struct ljca_i2c_dev *ljca_i2c;
+	int ret;
+
+	ljca_i2c = devm_kzalloc(&pdev->dev, sizeof(*ljca_i2c), GFP_KERNEL);
+	if (!ljca_i2c)
+		return -ENOMEM;
+
+	ljca_i2c->pdev = pdev;
+	ljca_i2c->i2c_info = dev_get_platdata(&pdev->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 = &pdev->dev;
+	device_set_node(&ljca_i2c->adap.dev, dev_fwnode(&pdev->dev));
+	i2c_set_adapdata(&ljca_i2c->adap, ljca_i2c);
+	snprintf(ljca_i2c->adap.name, sizeof(ljca_i2c->adap.name), "%s-%s-%d",
+		 dev_name(&pdev->dev), dev_name(pdev->dev.parent),
+		 ljca_i2c->i2c_info->id);
+
+	platform_set_drvdata(pdev, ljca_i2c);
+
+	ret = ljca_i2c_init(ljca_i2c, ljca_i2c->i2c_info->id);
+	if (ret) {
+		dev_err(&pdev->dev, "i2c init failed id:%d\n", ljca_i2c->i2c_info->id);
+		return -EIO;
+	}
+
+	ret = devm_i2c_add_adapter(&pdev->dev, &ljca_i2c->adap);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+#define LJCA_I2C_DRV_NAME "ljca-i2c"
+static const struct platform_device_id ljca_i2c_id[] = {
+	{ LJCA_I2C_DRV_NAME, 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, ljca_i2c_id);
+
+static struct platform_driver ljca_i2c_driver = {
+	.driver.name = LJCA_I2C_DRV_NAME,
+	.probe = ljca_i2c_probe,
+};
+
+module_platform_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 v2 4/5] 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 | 291 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 303 insertions(+)
 create mode 100644 drivers/spi/spi-ljca.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 3b1c0878bb85..b7ce4cbeb024 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -396,6 +396,17 @@ 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 MFD_LJCA
+	default MFD_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 be9ba40ef8d0..871a088294cb 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -68,6 +68,7 @@ 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..d55c30954bb7
--- /dev/null
+++ b/drivers/spi/spi-ljca.c
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel La Jolla Cove Adapter USB-SPI driver
+ *
+ * Copyright (c) 2023, Intel Corporation.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/dev_printk.h>
+#include <linux/mfd/ljca.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.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)
+
+struct spi_init_packet {
+	u8 index;
+	u8 speed;
+	u8 mode;
+} __packed;
+
+#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_xfer_packet {
+	u8 indicator;
+	s8 len;
+	u8 data[];
+} __packed;
+
+struct ljca_spi_dev {
+	struct platform_device *pdev;
+	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);
+		*(u16 *)&w_packet->data[0] = 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 int ljca_spi_transfer(struct ljca_spi_dev *ljca_spi, const u8 *tx_data,
+			     u8 *rx_data, u16 len)
+{
+	int ret;
+	int remaining = len;
+	int offset = 0;
+	int cur_len;
+	int complete;
+	int i;
+	int cmd;
+
+	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->pdev->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->pdev->dev, "ljca spi transfer failed!\n");
+
+	return ret;
+}
+
+static int ljca_spi_probe(struct platform_device *pdev)
+{
+	struct spi_controller *controller;
+	struct ljca_spi_dev *ljca_spi;
+	int ret;
+
+	controller = devm_spi_alloc_master(&pdev->dev, sizeof(*ljca_spi));
+	if (!controller)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, controller);
+	ljca_spi = spi_controller_get_devdata(controller);
+
+	ljca_spi->spi_info = dev_get_platdata(&pdev->dev);
+	ljca_spi->controller = controller;
+	ljca_spi->pdev = pdev;
+	device_set_node(&ljca_spi->controller->dev, dev_fwnode(&pdev->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(&pdev->dev, "Failed to register controller\n");
+
+	return ret;
+}
+
+static int ljca_spi_dev_remove(struct platform_device *pdev)
+{
+	struct spi_controller *controller = platform_get_drvdata(pdev);
+	struct ljca_spi_dev *ljca_spi = spi_controller_get_devdata(controller);
+
+	spi_unregister_controller(controller);
+	ljca_spi_deinit(ljca_spi);
+	return 0;
+}
+
+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-spi"
+static const struct platform_device_id ljca_spi_id[] = {
+	{ LJCA_SPI_DRV_NAME, 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, ljca_spi_id);
+
+static struct platform_driver spi_ljca_driver = {
+	.driver = {
+		.name	= LJCA_SPI_DRV_NAME,
+		.pm	= &ljca_spi_pm,
+	},
+	.probe		= ljca_spi_probe,
+	.remove		= ljca_spi_dev_remove,
+};
+
+module_platform_driver(spi_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-SPI driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(LJCA);
-- 
2.34.1

[PATCH v2 5/5] 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    | 22 +++++++++++++++++++
 1 file changed, 22 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..43b95effdefc
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-usb-devices-ljca
@@ -0,0 +1,22 @@
+What:		/sys/bus/usb/.../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/.../cmd
+Date:		July 2023
+KernelVersion:	6.4
+Contact:	Ye Xiang <xiang.ye@intel.com>
+Description:
+		Commands supported by LJCA device.
+		When read, it will return valid commands.
+		When write with a command, it will execute the command.
+		Valid commands are [dfu, debug]
+		dfu:	Echo dfu to this file so as to put the device into
+			DFU mode so the firmware can be updated.
+		debug:	Enable debug logging.
-- 
2.34.1

Re: [PATCH v2 4/5] spi: Add support for Intel LJCA USB SPI driver

[Mark Brown]

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On Sat, Feb 25, 2023 at 10:01:17PM +0800, Ye Xiang wrote:

> +struct spi_xfer_packet {
> +	u8 indicator;
> +	s8 len;
> +	u8 data[];
> +} __packed;

> +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);
> +		*(u16 *)&w_packet->data[0] = len;

Are there no endianness considerations here?

> +static int ljca_spi_transfer(struct ljca_spi_dev *ljca_spi, const u8 *tx_data,
> +			     u8 *rx_data, u16 len)
> +{

This function has one caller with barely anything in it - perhaps just
inline it?

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Re: [PATCH v2 4/5] spi: Add support for Intel LJCA USB SPI driver

[Ye, Xiang]

Hi Mark,

Thanks for the review.
On Tue, Feb 28, 2023 at 01:23:09AM +0800, Mark Brown wrote:
> On Sat, Feb 25, 2023 at 10:01:17PM +0800, Ye Xiang wrote:
> 
> > +struct spi_xfer_packet {
> > +	u8 indicator;
> > +	s8 len;
> > +	u8 data[];
> > +} __packed;
> 
> > +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);
> > +		*(u16 *)&w_packet->data[0] = len;
> 
> Are there no endianness considerations here?
Yes, it should be little endian. Will address this.
> 
> > +static int ljca_spi_transfer(struct ljca_spi_dev *ljca_spi, const u8 *tx_data,
> > +			     u8 *rx_data, u16 len)
> > +{
> 
> This function has one caller with barely anything in it - perhaps just
> inline it?
Agree. Will make this function inline.

--
Thanks
Ye Xiang

Re: [PATCH v2 2/5] gpio: Add support for Intel LJCA USB GPIO driver

[Linus Walleij]

On Sat, Feb 25, 2023 at 3:01 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>

Looks good to me, also looks like a really helpful adapter.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

I would appreciate if Andy could ACK it too, as Intel engineer.

Yours,
Linus Walleij