Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 769 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/i2c.c b/drivers/net/ethernet/mellanox/mlxsw/i2c.c
new file mode 100644
index 0000000000..d23f293e28
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlxsw/i2c.c
@@ -0,0 +1,769 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/* Copyright (c) 2016-2018 Mellanox Technologies. All rights reserved */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_data/mlxreg.h>
+#include <linux/slab.h>
+
+#include "cmd.h"
+#include "core.h"
+#include "i2c.h"
+#include "resources.h"
+
+#define MLXSW_I2C_CIR2_BASE		0x72000
+#define MLXSW_I2C_CIR_STATUS_OFF	0x18
+#define MLXSW_I2C_CIR2_OFF_STATUS	(MLXSW_I2C_CIR2_BASE + \
+					 MLXSW_I2C_CIR_STATUS_OFF)
+#define MLXSW_I2C_OPMOD_SHIFT		12
+#define MLXSW_I2C_EVENT_BIT_SHIFT	22
+#define MLXSW_I2C_GO_BIT_SHIFT		23
+#define MLXSW_I2C_CIR_CTRL_STATUS_SHIFT	24
+#define MLXSW_I2C_EVENT_BIT		BIT(MLXSW_I2C_EVENT_BIT_SHIFT)
+#define MLXSW_I2C_GO_BIT		BIT(MLXSW_I2C_GO_BIT_SHIFT)
+#define MLXSW_I2C_GO_OPMODE		BIT(MLXSW_I2C_OPMOD_SHIFT)
+#define MLXSW_I2C_SET_IMM_CMD		(MLXSW_I2C_GO_OPMODE | \
+					 MLXSW_CMD_OPCODE_QUERY_FW)
+#define MLXSW_I2C_PUSH_IMM_CMD		(MLXSW_I2C_GO_BIT | \
+					 MLXSW_I2C_SET_IMM_CMD)
+#define MLXSW_I2C_SET_CMD		(MLXSW_CMD_OPCODE_ACCESS_REG)
+#define MLXSW_I2C_PUSH_CMD		(MLXSW_I2C_GO_BIT | MLXSW_I2C_SET_CMD)
+#define MLXSW_I2C_TLV_HDR_SIZE		0x10
+#define MLXSW_I2C_ADDR_WIDTH		4
+#define MLXSW_I2C_PUSH_CMD_SIZE		(MLXSW_I2C_ADDR_WIDTH + 4)
+#define MLXSW_I2C_SET_EVENT_CMD		(MLXSW_I2C_EVENT_BIT)
+#define MLXSW_I2C_PUSH_EVENT_CMD	(MLXSW_I2C_GO_BIT | \
+					 MLXSW_I2C_SET_EVENT_CMD)
+#define MLXSW_I2C_READ_SEMA_SIZE	4
+#define MLXSW_I2C_PREP_SIZE		(MLXSW_I2C_ADDR_WIDTH + 28)
+#define MLXSW_I2C_MBOX_SIZE		20
+#define MLXSW_I2C_MBOX_OUT_PARAM_OFF	12
+#define MLXSW_I2C_MBOX_OFFSET_BITS	20
+#define MLXSW_I2C_MBOX_SIZE_BITS	12
+#define MLXSW_I2C_ADDR_BUF_SIZE		4
+#define MLXSW_I2C_BLK_DEF		32
+#define MLXSW_I2C_BLK_MAX		100
+#define MLXSW_I2C_RETRY			5
+#define MLXSW_I2C_TIMEOUT_MSECS		5000
+#define MLXSW_I2C_MAX_DATA_SIZE		256
+
+/* Driver can be initialized by kernel platform driver or from the user
+ * space. In the first case IRQ line number is passed through the platform
+ * data, otherwise default IRQ line is to be used. Default IRQ is relevant
+ * only for specific I2C slave address, allowing 3.4 MHz I2C path to the chip
+ * (special hardware feature for I2C acceleration).
+ */
+#define MLXSW_I2C_DEFAULT_IRQ		17
+#define MLXSW_FAST_I2C_SLAVE		0x37
+
+/**
+ * struct mlxsw_i2c - device private data:
+ * @cmd: command attributes;
+ * @cmd.mb_size_in: input mailbox size;
+ * @cmd.mb_off_in: input mailbox offset in register space;
+ * @cmd.mb_size_out: output mailbox size;
+ * @cmd.mb_off_out: output mailbox offset in register space;
+ * @cmd.lock: command execution lock;
+ * @dev: I2C device;
+ * @core: switch core pointer;
+ * @bus_info: bus info block;
+ * @block_size: maximum block size allowed to pass to under layer;
+ * @pdata: device platform data;
+ * @irq_work: interrupts work item;
+ * @irq: IRQ line number;
+ */
+struct mlxsw_i2c {
+	struct {
+		u32 mb_size_in;
+		u32 mb_off_in;
+		u32 mb_size_out;
+		u32 mb_off_out;
+		struct mutex lock;
+	} cmd;
+	struct device *dev;
+	struct mlxsw_core *core;
+	struct mlxsw_bus_info bus_info;
+	u16 block_size;
+	struct mlxreg_core_hotplug_platform_data *pdata;
+	struct work_struct irq_work;
+	int irq;
+};
+
+#define MLXSW_I2C_READ_MSG(_client, _addr_buf, _buf, _len) {	\
+	{ .addr = (_client)->addr,				\
+	  .buf = (_addr_buf),					\
+	  .len = MLXSW_I2C_ADDR_BUF_SIZE,			\
+	  .flags = 0 },						\
+	{ .addr = (_client)->addr,				\
+	  .buf = (_buf),					\
+	  .len = (_len),					\
+	  .flags = I2C_M_RD } }
+
+#define MLXSW_I2C_WRITE_MSG(_client, _buf, _len)		\
+	{ .addr = (_client)->addr,				\
+	  .buf = (u8 *)(_buf),					\
+	  .len = (_len),					\
+	  .flags = 0 }
+
+/* Routine converts in and out mail boxes offset and size. */
+static inline void
+mlxsw_i2c_convert_mbox(struct mlxsw_i2c *mlxsw_i2c, u8 *buf)
+{
+	u32 tmp;
+
+	/* Local in/out mailboxes: 20 bits for offset, 12 for size */
+	tmp = be32_to_cpup((__be32 *) buf);
+	mlxsw_i2c->cmd.mb_off_in = tmp &
+				   GENMASK(MLXSW_I2C_MBOX_OFFSET_BITS - 1, 0);
+	mlxsw_i2c->cmd.mb_size_in = (tmp & GENMASK(31,
+					MLXSW_I2C_MBOX_OFFSET_BITS)) >>
+					MLXSW_I2C_MBOX_OFFSET_BITS;
+
+	tmp = be32_to_cpup((__be32 *) (buf + MLXSW_I2C_ADDR_WIDTH));
+	mlxsw_i2c->cmd.mb_off_out = tmp &
+				    GENMASK(MLXSW_I2C_MBOX_OFFSET_BITS - 1, 0);
+	mlxsw_i2c->cmd.mb_size_out = (tmp & GENMASK(31,
+					MLXSW_I2C_MBOX_OFFSET_BITS)) >>
+					MLXSW_I2C_MBOX_OFFSET_BITS;
+}
+
+/* Routine obtains register size from mail box buffer. */
+static inline int mlxsw_i2c_get_reg_size(u8 *in_mbox)
+{
+	u16  tmp = be16_to_cpup((__be16 *) (in_mbox + MLXSW_I2C_TLV_HDR_SIZE));
+
+	return (tmp & 0x7ff) * 4 + MLXSW_I2C_TLV_HDR_SIZE;
+}
+
+/* Routine sets I2C device internal offset in the transaction buffer. */
+static inline void mlxsw_i2c_set_slave_addr(u8 *buf, u32 off)
+{
+	__be32 *val = (__be32 *) buf;
+
+	*val = htonl(off);
+}
+
+/* Routine waits until go bit is cleared. */
+static int mlxsw_i2c_wait_go_bit(struct i2c_client *client,
+				 struct mlxsw_i2c *mlxsw_i2c, u8 *p_status)
+{
+	u8 addr_buf[MLXSW_I2C_ADDR_BUF_SIZE];
+	u8 buf[MLXSW_I2C_READ_SEMA_SIZE];
+	int len = MLXSW_I2C_READ_SEMA_SIZE;
+	struct i2c_msg read_sema[] =
+		MLXSW_I2C_READ_MSG(client, addr_buf, buf, len);
+	bool wait_done = false;
+	unsigned long end;
+	int i = 0, err;
+
+	mlxsw_i2c_set_slave_addr(addr_buf, MLXSW_I2C_CIR2_OFF_STATUS);
+
+	end = jiffies + msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS);
+	do {
+		u32 ctrl;
+
+		err = i2c_transfer(client->adapter, read_sema,
+				   ARRAY_SIZE(read_sema));
+
+		ctrl = be32_to_cpu(*(__be32 *) buf);
+		if (err == ARRAY_SIZE(read_sema)) {
+			if (!(ctrl & MLXSW_I2C_GO_BIT)) {
+				wait_done = true;
+				*p_status = ctrl >>
+					    MLXSW_I2C_CIR_CTRL_STATUS_SHIFT;
+				break;
+			}
+		}
+		cond_resched();
+	} while ((time_before(jiffies, end)) || (i++ < MLXSW_I2C_RETRY));
+
+	if (wait_done) {
+		if (*p_status)
+			err = -EIO;
+	} else {
+		return -ETIMEDOUT;
+	}
+
+	return err > 0 ? 0 : err;
+}
+
+/* Routine posts a command to ASIC through mail box. */
+static int mlxsw_i2c_write_cmd(struct i2c_client *client,
+			       struct mlxsw_i2c *mlxsw_i2c,
+			       int immediate)
+{
+	__be32 push_cmd_buf[MLXSW_I2C_PUSH_CMD_SIZE / 4] = {
+		0, cpu_to_be32(MLXSW_I2C_PUSH_IMM_CMD)
+	};
+	__be32 prep_cmd_buf[MLXSW_I2C_PREP_SIZE / 4] = {
+		0, 0, 0, 0, 0, 0,
+		cpu_to_be32(client->adapter->nr & 0xffff),
+		cpu_to_be32(MLXSW_I2C_SET_IMM_CMD)
+	};
+	struct i2c_msg push_cmd =
+		MLXSW_I2C_WRITE_MSG(client, push_cmd_buf,
+				    MLXSW_I2C_PUSH_CMD_SIZE);
+	struct i2c_msg prep_cmd =
+		MLXSW_I2C_WRITE_MSG(client, prep_cmd_buf, MLXSW_I2C_PREP_SIZE);
+	int err;
+
+	if (!immediate) {
+		push_cmd_buf[1] = cpu_to_be32(MLXSW_I2C_PUSH_CMD);
+		prep_cmd_buf[7] = cpu_to_be32(MLXSW_I2C_SET_CMD);
+	}
+	mlxsw_i2c_set_slave_addr((u8 *)prep_cmd_buf,
+				 MLXSW_I2C_CIR2_BASE);
+	mlxsw_i2c_set_slave_addr((u8 *)push_cmd_buf,
+				 MLXSW_I2C_CIR2_OFF_STATUS);
+
+	/* Prepare Command Interface Register for transaction */
+	err = i2c_transfer(client->adapter, &prep_cmd, 1);
+	if (err < 0)
+		return err;
+	else if (err != 1)
+		return -EIO;
+
+	/* Write out Command Interface Register GO bit to push transaction */
+	err = i2c_transfer(client->adapter, &push_cmd, 1);
+	if (err < 0)
+		return err;
+	else if (err != 1)
+		return -EIO;
+
+	return 0;
+}
+
+/* Routine posts initialization command to ASIC through mail box. */
+static int
+mlxsw_i2c_write_init_cmd(struct i2c_client *client,
+			 struct mlxsw_i2c *mlxsw_i2c, u16 opcode, u32 in_mod)
+{
+	__be32 push_cmd_buf[MLXSW_I2C_PUSH_CMD_SIZE / 4] = {
+		0, cpu_to_be32(MLXSW_I2C_PUSH_EVENT_CMD)
+	};
+	__be32 prep_cmd_buf[MLXSW_I2C_PREP_SIZE / 4] = {
+		0, 0, 0, 0, 0, 0,
+		cpu_to_be32(client->adapter->nr & 0xffff),
+		cpu_to_be32(MLXSW_I2C_SET_EVENT_CMD)
+	};
+	struct i2c_msg push_cmd =
+		MLXSW_I2C_WRITE_MSG(client, push_cmd_buf,
+				    MLXSW_I2C_PUSH_CMD_SIZE);
+	struct i2c_msg prep_cmd =
+		MLXSW_I2C_WRITE_MSG(client, prep_cmd_buf, MLXSW_I2C_PREP_SIZE);
+	u8 status;
+	int err;
+
+	push_cmd_buf[1] = cpu_to_be32(MLXSW_I2C_PUSH_EVENT_CMD | opcode);
+	prep_cmd_buf[3] = cpu_to_be32(in_mod);
+	prep_cmd_buf[7] = cpu_to_be32(MLXSW_I2C_GO_BIT | opcode);
+	mlxsw_i2c_set_slave_addr((u8 *)prep_cmd_buf,
+				 MLXSW_I2C_CIR2_BASE);
+	mlxsw_i2c_set_slave_addr((u8 *)push_cmd_buf,
+				 MLXSW_I2C_CIR2_OFF_STATUS);
+
+	/* Prepare Command Interface Register for transaction */
+	err = i2c_transfer(client->adapter, &prep_cmd, 1);
+	if (err < 0)
+		return err;
+	else if (err != 1)
+		return -EIO;
+
+	/* Write out Command Interface Register GO bit to push transaction */
+	err = i2c_transfer(client->adapter, &push_cmd, 1);
+	if (err < 0)
+		return err;
+	else if (err != 1)
+		return -EIO;
+
+	/* Wait until go bit is cleared. */
+	err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, &status);
+	if (err) {
+		dev_err(&client->dev, "HW semaphore is not released");
+		return err;
+	}
+
+	/* Validate transaction completion status. */
+	if (status) {
+		dev_err(&client->dev, "Bad transaction completion status %x\n",
+			status);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/* Routine obtains mail box offsets from ASIC register space. */
+static int mlxsw_i2c_get_mbox(struct i2c_client *client,
+			      struct mlxsw_i2c *mlxsw_i2c)
+{
+	u8 addr_buf[MLXSW_I2C_ADDR_BUF_SIZE];
+	u8 buf[MLXSW_I2C_MBOX_SIZE];
+	struct i2c_msg mbox_cmd[] =
+		MLXSW_I2C_READ_MSG(client, addr_buf, buf, MLXSW_I2C_MBOX_SIZE);
+	int err;
+
+	/* Read mail boxes offsets. */
+	mlxsw_i2c_set_slave_addr(addr_buf, MLXSW_I2C_CIR2_BASE);
+	err = i2c_transfer(client->adapter, mbox_cmd, 2);
+	if (err != 2) {
+		dev_err(&client->dev, "Could not obtain mail boxes\n");
+		if (!err)
+			return -EIO;
+		else
+			return err;
+	}
+
+	/* Convert mail boxes. */
+	mlxsw_i2c_convert_mbox(mlxsw_i2c, &buf[MLXSW_I2C_MBOX_OUT_PARAM_OFF]);
+
+	return err;
+}
+
+/* Routine sends I2C write transaction to ASIC device. */
+static int
+mlxsw_i2c_write(struct device *dev, size_t in_mbox_size, u8 *in_mbox, int num,
+		u8 *p_status)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client);
+	unsigned long timeout = msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS);
+	int off = mlxsw_i2c->cmd.mb_off_in, chunk_size, i, j;
+	unsigned long end;
+	u8 *tran_buf;
+	struct i2c_msg write_tran =
+		MLXSW_I2C_WRITE_MSG(client, NULL, MLXSW_I2C_PUSH_CMD_SIZE);
+	int err;
+
+	tran_buf = kmalloc(mlxsw_i2c->block_size + MLXSW_I2C_ADDR_BUF_SIZE,
+			   GFP_KERNEL);
+	if (!tran_buf)
+		return -ENOMEM;
+
+	write_tran.buf = tran_buf;
+	for (i = 0; i < num; i++) {
+		chunk_size = (in_mbox_size > mlxsw_i2c->block_size) ?
+			     mlxsw_i2c->block_size : in_mbox_size;
+		write_tran.len = MLXSW_I2C_ADDR_WIDTH + chunk_size;
+		mlxsw_i2c_set_slave_addr(tran_buf, off);
+		memcpy(&tran_buf[MLXSW_I2C_ADDR_BUF_SIZE], in_mbox +
+		       mlxsw_i2c->block_size * i, chunk_size);
+
+		j = 0;
+		end = jiffies + timeout;
+		do {
+			err = i2c_transfer(client->adapter, &write_tran, 1);
+			if (err == 1)
+				break;
+
+			cond_resched();
+		} while ((time_before(jiffies, end)) ||
+			 (j++ < MLXSW_I2C_RETRY));
+
+		if (err != 1) {
+			if (!err) {
+				err = -EIO;
+				goto mlxsw_i2c_write_exit;
+			}
+		}
+
+		off += chunk_size;
+		in_mbox_size -= chunk_size;
+	}
+
+	/* Prepare and write out Command Interface Register for transaction. */
+	err = mlxsw_i2c_write_cmd(client, mlxsw_i2c, 0);
+	if (err) {
+		dev_err(&client->dev, "Could not start transaction");
+		err = -EIO;
+		goto mlxsw_i2c_write_exit;
+	}
+
+	/* Wait until go bit is cleared. */
+	err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, p_status);
+	if (err) {
+		dev_err(&client->dev, "HW semaphore is not released");
+		goto mlxsw_i2c_write_exit;
+	}
+
+	/* Validate transaction completion status. */
+	if (*p_status) {
+		dev_err(&client->dev, "Bad transaction completion status %x\n",
+			*p_status);
+		err = -EIO;
+	}
+
+mlxsw_i2c_write_exit:
+	kfree(tran_buf);
+	return err;
+}
+
+/* Routine executes I2C command. */
+static int
+mlxsw_i2c_cmd(struct device *dev, u16 opcode, u32 in_mod, size_t in_mbox_size,
+	      u8 *in_mbox, size_t out_mbox_size, u8 *out_mbox, u8 *status)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client);
+	unsigned long timeout = msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS);
+	u8 tran_buf[MLXSW_I2C_ADDR_BUF_SIZE];
+	int num, chunk_size, reg_size, i, j;
+	int off = mlxsw_i2c->cmd.mb_off_out;
+	unsigned long end;
+	struct i2c_msg read_tran[] =
+		MLXSW_I2C_READ_MSG(client, tran_buf, NULL, 0);
+	int err;
+
+	WARN_ON(in_mbox_size % sizeof(u32) || out_mbox_size % sizeof(u32));
+
+	if (in_mbox) {
+		reg_size = mlxsw_i2c_get_reg_size(in_mbox);
+		num = reg_size / mlxsw_i2c->block_size;
+		if (reg_size % mlxsw_i2c->block_size)
+			num++;
+
+		if (mutex_lock_interruptible(&mlxsw_i2c->cmd.lock) < 0) {
+			dev_err(&client->dev, "Could not acquire lock");
+			return -EINVAL;
+		}
+
+		err = mlxsw_i2c_write(dev, reg_size, in_mbox, num, status);
+		if (err)
+			goto cmd_fail;
+
+		/* No out mailbox is case of write transaction. */
+		if (!out_mbox) {
+			mutex_unlock(&mlxsw_i2c->cmd.lock);
+			return 0;
+		}
+	} else {
+		/* No input mailbox is case of initialization query command. */
+		reg_size = MLXSW_I2C_MAX_DATA_SIZE;
+		num = DIV_ROUND_UP(reg_size, mlxsw_i2c->block_size);
+
+		if (mutex_lock_interruptible(&mlxsw_i2c->cmd.lock) < 0) {
+			dev_err(&client->dev, "Could not acquire lock");
+			return -EINVAL;
+		}
+
+		err = mlxsw_i2c_write_init_cmd(client, mlxsw_i2c, opcode,
+					       in_mod);
+		if (err)
+			goto cmd_fail;
+	}
+
+	/* Send read transaction to get output mailbox content. */
+	read_tran[1].buf = out_mbox;
+	for (i = 0; i < num; i++) {
+		chunk_size = (reg_size > mlxsw_i2c->block_size) ?
+			     mlxsw_i2c->block_size : reg_size;
+		read_tran[1].len = chunk_size;
+		mlxsw_i2c_set_slave_addr(tran_buf, off);
+
+		j = 0;
+		end = jiffies + timeout;
+		do {
+			err = i2c_transfer(client->adapter, read_tran,
+					   ARRAY_SIZE(read_tran));
+			if (err == ARRAY_SIZE(read_tran))
+				break;
+
+			cond_resched();
+		} while ((time_before(jiffies, end)) ||
+			 (j++ < MLXSW_I2C_RETRY));
+
+		if (err != ARRAY_SIZE(read_tran)) {
+			if (!err)
+				err = -EIO;
+
+			goto cmd_fail;
+		}
+
+		off += chunk_size;
+		reg_size -= chunk_size;
+		read_tran[1].buf += chunk_size;
+	}
+
+	mutex_unlock(&mlxsw_i2c->cmd.lock);
+
+	return 0;
+
+cmd_fail:
+	mutex_unlock(&mlxsw_i2c->cmd.lock);
+	return err;
+}
+
+static int mlxsw_i2c_cmd_exec(void *bus_priv, u16 opcode, u8 opcode_mod,
+			      u32 in_mod, bool out_mbox_direct,
+			      char *in_mbox, size_t in_mbox_size,
+			      char *out_mbox, size_t out_mbox_size,
+			      u8 *status)
+{
+	struct mlxsw_i2c *mlxsw_i2c = bus_priv;
+
+	return mlxsw_i2c_cmd(mlxsw_i2c->dev, opcode, in_mod, in_mbox_size,
+			     in_mbox, out_mbox_size, out_mbox, status);
+}
+
+static bool mlxsw_i2c_skb_transmit_busy(void *bus_priv,
+					const struct mlxsw_tx_info *tx_info)
+{
+	return false;
+}
+
+static int mlxsw_i2c_skb_transmit(void *bus_priv, struct sk_buff *skb,
+				  const struct mlxsw_tx_info *tx_info)
+{
+	return 0;
+}
+
+static int
+mlxsw_i2c_init(void *bus_priv, struct mlxsw_core *mlxsw_core,
+	       const struct mlxsw_config_profile *profile,
+	       struct mlxsw_res *res)
+{
+	struct mlxsw_i2c *mlxsw_i2c = bus_priv;
+	char *mbox;
+	int err;
+
+	mlxsw_i2c->core = mlxsw_core;
+
+	mbox = mlxsw_cmd_mbox_alloc();
+	if (!mbox)
+		return -ENOMEM;
+
+	err = mlxsw_cmd_query_fw(mlxsw_core, mbox);
+	if (err)
+		goto mbox_put;
+
+	mlxsw_i2c->bus_info.fw_rev.major =
+		mlxsw_cmd_mbox_query_fw_fw_rev_major_get(mbox);
+	mlxsw_i2c->bus_info.fw_rev.minor =
+		mlxsw_cmd_mbox_query_fw_fw_rev_minor_get(mbox);
+	mlxsw_i2c->bus_info.fw_rev.subminor =
+		mlxsw_cmd_mbox_query_fw_fw_rev_subminor_get(mbox);
+
+	err = mlxsw_core_resources_query(mlxsw_core, mbox, res);
+
+mbox_put:
+	mlxsw_cmd_mbox_free(mbox);
+	return err;
+}
+
+static void mlxsw_i2c_fini(void *bus_priv)
+{
+	struct mlxsw_i2c *mlxsw_i2c = bus_priv;
+
+	mlxsw_i2c->core = NULL;
+}
+
+static void mlxsw_i2c_work_handler(struct work_struct *work)
+{
+	struct mlxsw_i2c *mlxsw_i2c;
+
+	mlxsw_i2c = container_of(work, struct mlxsw_i2c, irq_work);
+	mlxsw_core_irq_event_handlers_call(mlxsw_i2c->core);
+}
+
+static irqreturn_t mlxsw_i2c_irq_handler(int irq, void *dev)
+{
+	struct mlxsw_i2c *mlxsw_i2c = dev;
+
+	mlxsw_core_schedule_work(&mlxsw_i2c->irq_work);
+
+	/* Interrupt handler shares IRQ line with 'main' interrupt handler.
+	 * Return here IRQ_NONE, while main handler will return IRQ_HANDLED.
+	 */
+	return IRQ_NONE;
+}
+
+static int mlxsw_i2c_irq_init(struct mlxsw_i2c *mlxsw_i2c, u8 addr)
+{
+	int err;
+
+	/* Initialize interrupt handler if system hotplug driver is reachable,
+	 * otherwise interrupt line is not enabled and interrupts will not be
+	 * raised to CPU. Also request_irq() call will be not valid.
+	 */
+	if (!IS_REACHABLE(CONFIG_MLXREG_HOTPLUG))
+		return 0;
+
+	/* Set default interrupt line. */
+	if (mlxsw_i2c->pdata && mlxsw_i2c->pdata->irq)
+		mlxsw_i2c->irq = mlxsw_i2c->pdata->irq;
+	else if (addr == MLXSW_FAST_I2C_SLAVE)
+		mlxsw_i2c->irq = MLXSW_I2C_DEFAULT_IRQ;
+
+	if (!mlxsw_i2c->irq)
+		return 0;
+
+	INIT_WORK(&mlxsw_i2c->irq_work, mlxsw_i2c_work_handler);
+	err = request_irq(mlxsw_i2c->irq, mlxsw_i2c_irq_handler,
+			  IRQF_TRIGGER_FALLING | IRQF_SHARED, "mlxsw-i2c",
+			  mlxsw_i2c);
+	if (err) {
+		dev_err(mlxsw_i2c->bus_info.dev, "Failed to request irq: %d\n",
+			err);
+		return err;
+	}
+
+	return 0;
+}
+
+static void mlxsw_i2c_irq_fini(struct mlxsw_i2c *mlxsw_i2c)
+{
+	if (!IS_REACHABLE(CONFIG_MLXREG_HOTPLUG) || !mlxsw_i2c->irq)
+		return;
+	cancel_work_sync(&mlxsw_i2c->irq_work);
+	free_irq(mlxsw_i2c->irq, mlxsw_i2c);
+}
+
+static const struct mlxsw_bus mlxsw_i2c_bus = {
+	.kind			= "i2c",
+	.init			= mlxsw_i2c_init,
+	.fini			= mlxsw_i2c_fini,
+	.skb_transmit_busy	= mlxsw_i2c_skb_transmit_busy,
+	.skb_transmit		= mlxsw_i2c_skb_transmit,
+	.cmd_exec		= mlxsw_i2c_cmd_exec,
+};
+
+static int mlxsw_i2c_probe(struct i2c_client *client)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	const struct i2c_adapter_quirks *quirks = client->adapter->quirks;
+	struct mlxsw_i2c *mlxsw_i2c;
+	u8 status;
+	int err;
+
+	mlxsw_i2c = devm_kzalloc(&client->dev, sizeof(*mlxsw_i2c), GFP_KERNEL);
+	if (!mlxsw_i2c)
+		return -ENOMEM;
+
+	if (quirks) {
+		if ((quirks->max_read_len &&
+		     quirks->max_read_len < MLXSW_I2C_BLK_DEF) ||
+		    (quirks->max_write_len &&
+		     quirks->max_write_len < MLXSW_I2C_BLK_DEF)) {
+			dev_err(&client->dev, "Insufficient transaction buffer length\n");
+			return -EOPNOTSUPP;
+		}
+
+		mlxsw_i2c->block_size = min_t(u16, MLXSW_I2C_BLK_MAX,
+					      min_t(u16, quirks->max_read_len,
+						    quirks->max_write_len));
+	} else {
+		mlxsw_i2c->block_size = MLXSW_I2C_BLK_DEF;
+	}
+
+	i2c_set_clientdata(client, mlxsw_i2c);
+	mutex_init(&mlxsw_i2c->cmd.lock);
+
+	/* In order to use mailboxes through the i2c, special area is reserved
+	 * on the i2c address space that can be used for input and output
+	 * mailboxes. Such mailboxes are called local mailboxes. When using a
+	 * local mailbox, software should specify 0 as the Input/Output
+	 * parameters. The location of the Local Mailbox addresses on the i2c
+	 * space can be retrieved through the QUERY_FW command.
+	 * For this purpose QUERY_FW is to be issued with opcode modifier equal
+	 * 0x01. For such command the output parameter is an immediate value.
+	 * Here QUERY_FW command is invoked for ASIC probing and for getting
+	 * local mailboxes addresses from immedate output parameters.
+	 */
+
+	/* Prepare and write out Command Interface Register for transaction */
+	err = mlxsw_i2c_write_cmd(client, mlxsw_i2c, 1);
+	if (err) {
+		dev_err(&client->dev, "Could not start transaction");
+		goto errout;
+	}
+
+	/* Wait until go bit is cleared. */
+	err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, &status);
+	if (err) {
+		dev_err(&client->dev, "HW semaphore is not released");
+		goto errout;
+	}
+
+	/* Validate transaction completion status. */
+	if (status) {
+		dev_err(&client->dev, "Bad transaction completion status %x\n",
+			status);
+		err = -EIO;
+		goto errout;
+	}
+
+	/* Get mailbox offsets. */
+	err = mlxsw_i2c_get_mbox(client, mlxsw_i2c);
+	if (err < 0) {
+		dev_err(&client->dev, "Fail to get mailboxes\n");
+		goto errout;
+	}
+
+	dev_info(&client->dev, "%s mb size=%x off=0x%08x out mb size=%x off=0x%08x\n",
+		 id->name, mlxsw_i2c->cmd.mb_size_in,
+		 mlxsw_i2c->cmd.mb_off_in, mlxsw_i2c->cmd.mb_size_out,
+		 mlxsw_i2c->cmd.mb_off_out);
+
+	/* Register device bus. */
+	mlxsw_i2c->bus_info.device_kind = id->name;
+	mlxsw_i2c->bus_info.device_name = client->name;
+	mlxsw_i2c->bus_info.dev = &client->dev;
+	mlxsw_i2c->bus_info.low_frequency = true;
+	mlxsw_i2c->dev = &client->dev;
+	mlxsw_i2c->pdata = client->dev.platform_data;
+
+	err = mlxsw_i2c_irq_init(mlxsw_i2c, client->addr);
+	if (err)
+		goto errout;
+
+	err = mlxsw_core_bus_device_register(&mlxsw_i2c->bus_info,
+					     &mlxsw_i2c_bus, mlxsw_i2c, false,
+					     NULL, NULL);
+	if (err) {
+		dev_err(&client->dev, "Fail to register core bus\n");
+		goto err_bus_device_register;
+	}
+
+	return 0;
+
+err_bus_device_register:
+	mlxsw_i2c_irq_fini(mlxsw_i2c);
+errout:
+	mutex_destroy(&mlxsw_i2c->cmd.lock);
+	i2c_set_clientdata(client, NULL);
+
+	return err;
+}
+
+static void mlxsw_i2c_remove(struct i2c_client *client)
+{
+	struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client);
+
+	mlxsw_core_bus_device_unregister(mlxsw_i2c->core, false);
+	mlxsw_i2c_irq_fini(mlxsw_i2c);
+	mutex_destroy(&mlxsw_i2c->cmd.lock);
+}
+
+int mlxsw_i2c_driver_register(struct i2c_driver *i2c_driver)
+{
+	i2c_driver->probe = mlxsw_i2c_probe;
+	i2c_driver->remove = mlxsw_i2c_remove;
+	return i2c_add_driver(i2c_driver);
+}
+EXPORT_SYMBOL(mlxsw_i2c_driver_register);
+
+void mlxsw_i2c_driver_unregister(struct i2c_driver *i2c_driver)
+{
+	i2c_del_driver(i2c_driver);
+}
+EXPORT_SYMBOL(mlxsw_i2c_driver_unregister);
+
+MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
+MODULE_DESCRIPTION("Mellanox switch I2C interface driver");
+MODULE_LICENSE("Dual BSD/GPL");