i2c: mlxbf: I2C SMBus driver for Mellanox BlueField SoC

Add BlueField I2C driver to offer master and slave support for
Mellanox BlueField SoCs. The driver implements an SMBus adapter
and interfaces to multiple busses that can be probed using both
ACPI and Device Tree infrastructures.

The driver supports several SMBus operations to transfer data
back and forth from/to various I2C devices. It is mainly intended
to be consumed by userspace tools and utilities, such as i2c-tools
and decode-dimms to collect memory module information.

On the other hand, the driver has a slave function to support,
among others, an IPMB interface that requires both master and
slave functions to handle transfers between the BlueField SoC
and a board management controllers (e.g., BMC).

Signed-off-by: Khalil Blaiech <kblaiech@mellanox.com>
Reviewed-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

4 files changed, 2526 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index f0068bceeb61..8580de35179f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11071,6 +11071,12 @@ W:	http://www.melfas.com
 F:	Documentation/devicetree/bindings/input/touchscreen/melfas_mip4.txt
 F:	drivers/input/touchscreen/melfas_mip4.c
 
+MELLANOX BLUEFIELD I2C DRIVER
+M:	Khalil Blaiech <kblaiech@mellanox.com>
+L:	linux-i2c@vger.kernel.org
+S:	Supported
+F:	drivers/i2c/busses/i2c-mlxbf.c
+
 MELLANOX ETHERNET DRIVER (mlx4_en)
 M:	Tariq Toukan <tariqt@nvidia.com>
 L:	netdev@vger.kernel.org
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 2077ed8de681..96685b273f63 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -730,6 +730,19 @@ config I2C_LPC2K
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-lpc2k.
 
+config I2C_MLXBF
+        tristate "Mellanox BlueField I2C controller"
+        depends on ARM64
+        help
+          Enabling this option will add I2C SMBus support for Mellanox BlueField
+          system.
+
+          This driver can also be built as a module. If so, the module will be
+          called i2c-mlxbf.
+
+          This driver implements an I2C SMBus host controller and enables both
+          master and slave functions.
+
 config I2C_MESON
 	tristate "Amlogic Meson I2C controller"
 	depends on ARCH_MESON || COMPILE_TEST
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 19aff0e45cb5..683c49faca05 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -140,6 +140,7 @@ obj-$(CONFIG_I2C_BRCMSTB)	+= i2c-brcmstb.o
 obj-$(CONFIG_I2C_CROS_EC_TUNNEL)	+= i2c-cros-ec-tunnel.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
 obj-$(CONFIG_I2C_ICY)		+= i2c-icy.o
+obj-$(CONFIG_I2C_MLXBF)		+= i2c-mlxbf.o
 obj-$(CONFIG_I2C_MLXCPLD)	+= i2c-mlxcpld.o
 obj-$(CONFIG_I2C_OPAL)		+= i2c-opal.o
 obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o
diff --git a/drivers/i2c/busses/i2c-mlxbf.c b/drivers/i2c/busses/i2c-mlxbf.c
new file mode 100644
index 000000000000..ee59e0da082d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-mlxbf.c
@@ -0,0 +1,2506 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Mellanox BlueField I2C bus driver
+ *
+ *  Copyright (C) 2020 Mellanox Technologies, Ltd.
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+
+/* Defines what functionality is present. */
+#define MLXBF_I2C_FUNC_SMBUS_BLOCK \
+	(I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL)
+
+#define MLXBF_I2C_FUNC_SMBUS_DEFAULT \
+	(I2C_FUNC_SMBUS_BYTE      | I2C_FUNC_SMBUS_BYTE_DATA | \
+	 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK | \
+	 I2C_FUNC_SMBUS_PROC_CALL)
+
+#define MLXBF_I2C_FUNC_ALL \
+	(MLXBF_I2C_FUNC_SMBUS_DEFAULT | MLXBF_I2C_FUNC_SMBUS_BLOCK | \
+	 I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SLAVE)
+
+#define MLXBF_I2C_SMBUS_MAX        3
+
+/* Shared resources info in BlueField platforms. */
+
+#define MLXBF_I2C_COALESCE_TYU_ADDR    0x02801300
+#define MLXBF_I2C_COALESCE_TYU_SIZE    0x010
+
+#define MLXBF_I2C_GPIO_TYU_ADDR        0x02802000
+#define MLXBF_I2C_GPIO_TYU_SIZE        0x100
+
+#define MLXBF_I2C_COREPLL_TYU_ADDR     0x02800358
+#define MLXBF_I2C_COREPLL_TYU_SIZE     0x008
+
+#define MLXBF_I2C_COREPLL_YU_ADDR      0x02800c30
+#define MLXBF_I2C_COREPLL_YU_SIZE      0x00c
+
+#define MLXBF_I2C_SHARED_RES_MAX       3
+
+/*
+ * Note that the following SMBus, CAUSE, GPIO and PLL register addresses
+ * refer to their respective offsets relative to the corresponding
+ * memory-mapped region whose addresses are specified in either the DT or
+ * the ACPI tables or above.
+ */
+
+/*
+ * SMBus Master core clock frequency. Timing configurations are
+ * strongly dependent on the core clock frequency of the SMBus
+ * Master. Default value is set to 400MHz.
+ */
+#define MLXBF_I2C_TYU_PLL_OUT_FREQ  (400 * 1000 * 1000)
+/* Reference clock for Bluefield 1 - 156 MHz. */
+#define MLXBF_I2C_TYU_PLL_IN_FREQ   (156 * 1000 * 1000)
+/* Reference clock for BlueField 2 - 200 MHz. */
+#define MLXBF_I2C_YU_PLL_IN_FREQ    (200 * 1000 * 1000)
+
+/* Constant used to determine the PLL frequency. */
+#define MLNXBF_I2C_COREPLL_CONST    16384
+
+/* PLL registers. */
+#define MLXBF_I2C_CORE_PLL_REG0         0x0
+#define MLXBF_I2C_CORE_PLL_REG1         0x4
+#define MLXBF_I2C_CORE_PLL_REG2         0x8
+
+/* OR cause register. */
+#define MLXBF_I2C_CAUSE_OR_EVTEN0    0x14
+#define MLXBF_I2C_CAUSE_OR_CLEAR     0x18
+
+/* Arbiter Cause Register. */
+#define MLXBF_I2C_CAUSE_ARBITER      0x1c
+
+/*
+ * Cause Status flags. Note that those bits might be considered
+ * as interrupt enabled bits.
+ */
+
+/* Transaction ended with STOP. */
+#define MLXBF_I2C_CAUSE_TRANSACTION_ENDED  BIT(0)
+/* Master arbitration lost. */
+#define MLXBF_I2C_CAUSE_M_ARBITRATION_LOST BIT(1)
+/* Unexpected start detected. */
+#define MLXBF_I2C_CAUSE_UNEXPECTED_START   BIT(2)
+/* Unexpected stop detected. */
+#define MLXBF_I2C_CAUSE_UNEXPECTED_STOP    BIT(3)
+/* Wait for transfer continuation. */
+#define MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA   BIT(4)
+/* Failed to generate STOP. */
+#define MLXBF_I2C_CAUSE_PUT_STOP_FAILED    BIT(5)
+/* Failed to generate START. */
+#define MLXBF_I2C_CAUSE_PUT_START_FAILED   BIT(6)
+/* Clock toggle completed. */
+#define MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE    BIT(7)
+/* Transfer timeout occurred. */
+#define MLXBF_I2C_CAUSE_M_FW_TIMEOUT       BIT(8)
+/* Master busy bit reset. */
+#define MLXBF_I2C_CAUSE_M_GW_BUSY_FALL     BIT(9)
+
+#define MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK     GENMASK(9, 0)
+
+#define MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR \
+	(MLXBF_I2C_CAUSE_M_ARBITRATION_LOST | \
+	 MLXBF_I2C_CAUSE_UNEXPECTED_START | \
+	 MLXBF_I2C_CAUSE_UNEXPECTED_STOP | \
+	 MLXBF_I2C_CAUSE_PUT_STOP_FAILED | \
+	 MLXBF_I2C_CAUSE_PUT_START_FAILED | \
+	 MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE | \
+	 MLXBF_I2C_CAUSE_M_FW_TIMEOUT)
+
+/*
+ * Slave cause status flags. Note that those bits might be considered
+ * as interrupt enabled bits.
+ */
+
+/* Write transaction received successfully. */
+#define MLXBF_I2C_CAUSE_WRITE_SUCCESS         BIT(0)
+/* Read transaction received, waiting for response. */
+#define MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE BIT(13)
+/* Slave busy bit reset. */
+#define MLXBF_I2C_CAUSE_S_GW_BUSY_FALL        BIT(18)
+
+#define MLXBF_I2C_CAUSE_SLAVE_ARBITER_BITS_MASK     GENMASK(20, 0)
+
+/* Cause coalesce registers. */
+#define MLXBF_I2C_CAUSE_COALESCE_0        0x00
+#define MLXBF_I2C_CAUSE_COALESCE_1        0x04
+#define MLXBF_I2C_CAUSE_COALESCE_2        0x08
+
+#define MLXBF_I2C_CAUSE_TYU_SLAVE_BIT   MLXBF_I2C_SMBUS_MAX
+#define MLXBF_I2C_CAUSE_YU_SLAVE_BIT    1
+
+/* Functional enable register. */
+#define MLXBF_I2C_GPIO_0_FUNC_EN_0    0x28
+/* Force OE enable register. */
+#define MLXBF_I2C_GPIO_0_FORCE_OE_EN  0x30
+/*
+ * Note that Smbus GWs are on GPIOs 30:25. Two pins are used to control
+ * SDA/SCL lines:
+ *
+ *  SMBUS GW0 -> bits[26:25]
+ *  SMBUS GW1 -> bits[28:27]
+ *  SMBUS GW2 -> bits[30:29]
+ */
+#define MLXBF_I2C_GPIO_SMBUS_GW_PINS(num) (25 + ((num) << 1))
+
+/* Note that gw_id can be 0,1 or 2. */
+#define MLXBF_I2C_GPIO_SMBUS_GW_MASK(num) \
+	(0xffffffff & (~(0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num))))
+
+#define MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(num, val) \
+	((val) & MLXBF_I2C_GPIO_SMBUS_GW_MASK(num))
+
+#define MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(num, val) \
+	((val) | (0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num)))
+
+/* SMBus timing parameters. */
+#define MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH    0x00
+#define MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE     0x04
+#define MLXBF_I2C_SMBUS_TIMER_THOLD               0x08
+#define MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP   0x0c
+#define MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA         0x10
+#define MLXBF_I2C_SMBUS_THIGH_MAX_TBUF            0x14
+#define MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT           0x18
+
+enum {
+	MLXBF_I2C_TIMING_100KHZ = 100000,
+	MLXBF_I2C_TIMING_400KHZ = 400000,
+	MLXBF_I2C_TIMING_1000KHZ = 1000000,
+};
+
+/*
+ * Defines SMBus operating frequency and core clock frequency.
+ * According to ADB files, default values are compliant to 100KHz SMBus
+ * @ 400MHz core clock. The driver should be able to calculate core
+ * frequency based on PLL parameters.
+ */
+#define MLXBF_I2C_COREPLL_FREQ          MLXBF_I2C_TYU_PLL_OUT_FREQ
+
+/* Core PLL TYU configuration. */
+#define MLXBF_I2C_COREPLL_CORE_F_TYU_MASK   GENMASK(12, 0)
+#define MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK  GENMASK(3, 0)
+#define MLXBF_I2C_COREPLL_CORE_R_TYU_MASK   GENMASK(5, 0)
+
+#define MLXBF_I2C_COREPLL_CORE_F_TYU_SHIFT  3
+#define MLXBF_I2C_COREPLL_CORE_OD_TYU_SHIFT 16
+#define MLXBF_I2C_COREPLL_CORE_R_TYU_SHIFT  20
+
+/* Core PLL YU configuration. */
+#define MLXBF_I2C_COREPLL_CORE_F_YU_MASK    GENMASK(25, 0)
+#define MLXBF_I2C_COREPLL_CORE_OD_YU_MASK   GENMASK(3, 0)
+#define MLXBF_I2C_COREPLL_CORE_R_YU_MASK    GENMASK(5, 0)
+
+#define MLXBF_I2C_COREPLL_CORE_F_YU_SHIFT   0
+#define MLXBF_I2C_COREPLL_CORE_OD_YU_SHIFT  1
+#define MLXBF_I2C_COREPLL_CORE_R_YU_SHIFT   26
+
+/* Core PLL frequency. */
+static u64 mlxbf_i2c_corepll_frequency;
+
+/* SMBus Master GW. */
+#define MLXBF_I2C_SMBUS_MASTER_GW     0x200
+/* Number of bytes received and sent. */
+#define MLXBF_I2C_SMBUS_RS_BYTES      0x300
+/* Packet error check (PEC) value. */
+#define MLXBF_I2C_SMBUS_MASTER_PEC    0x304
+/* Status bits (ACK/NACK/FW Timeout). */
+#define MLXBF_I2C_SMBUS_MASTER_STATUS 0x308
+/* SMbus Master Finite State Machine. */
+#define MLXBF_I2C_SMBUS_MASTER_FSM    0x310
+
+/*
+ * When enabled, the master will issue a stop condition in case of
+ * timeout while waiting for FW response.
+ */
+#define MLXBF_I2C_SMBUS_EN_FW_TIMEOUT 0x31c
+
+/* SMBus master GW control bits offset in MLXBF_I2C_SMBUS_MASTER_GW[31:3]. */
+#define MLXBF_I2C_MASTER_LOCK_BIT         BIT(31) /* Lock bit. */
+#define MLXBF_I2C_MASTER_BUSY_BIT         BIT(30) /* Busy bit. */
+#define MLXBF_I2C_MASTER_START_BIT        BIT(29) /* Control start. */
+#define MLXBF_I2C_MASTER_CTL_WRITE_BIT    BIT(28) /* Control write phase. */
+#define MLXBF_I2C_MASTER_CTL_READ_BIT     BIT(19) /* Control read phase. */
+#define MLXBF_I2C_MASTER_STOP_BIT         BIT(3)  /* Control stop. */
+
+#define MLXBF_I2C_MASTER_ENABLE \
+	(MLXBF_I2C_MASTER_LOCK_BIT | MLXBF_I2C_MASTER_BUSY_BIT | \
+	 MLXBF_I2C_MASTER_START_BIT | MLXBF_I2C_MASTER_STOP_BIT)
+
+#define MLXBF_I2C_MASTER_ENABLE_WRITE \
+	(MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_WRITE_BIT)
+
+#define MLXBF_I2C_MASTER_ENABLE_READ \
+	(MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_READ_BIT)
+
+#define MLXBF_I2C_MASTER_SLV_ADDR_SHIFT   12 /* Slave address shift. */
+#define MLXBF_I2C_MASTER_WRITE_SHIFT      21 /* Control write bytes shift. */
+#define MLXBF_I2C_MASTER_SEND_PEC_SHIFT   20 /* Send PEC byte shift. */
+#define MLXBF_I2C_MASTER_PARSE_EXP_SHIFT  11 /* Parse expected bytes shift. */
+#define MLXBF_I2C_MASTER_READ_SHIFT       4  /* Control read bytes shift. */
+
+/* SMBus master GW Data descriptor. */
+#define MLXBF_I2C_MASTER_DATA_DESC_ADDR   0x280
+#define MLXBF_I2C_MASTER_DATA_DESC_SIZE   0x80 /* Size in bytes. */
+
+/* Maximum bytes to read/write per SMBus transaction. */
+#define MLXBF_I2C_MASTER_DATA_R_LENGTH  MLXBF_I2C_MASTER_DATA_DESC_SIZE
+#define MLXBF_I2C_MASTER_DATA_W_LENGTH (MLXBF_I2C_MASTER_DATA_DESC_SIZE - 1)
+
+/* All bytes were transmitted. */
+#define MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE      BIT(0)
+/* NACK received. */
+#define MLXBF_I2C_SMBUS_STATUS_NACK_RCV           BIT(1)
+/* Slave's byte count >128 bytes. */
+#define MLXBF_I2C_SMBUS_STATUS_READ_ERR           BIT(2)
+/* Timeout occurred. */
+#define MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT         BIT(3)
+
+#define MLXBF_I2C_SMBUS_MASTER_STATUS_MASK        GENMASK(3, 0)
+
+#define MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR \
+	(MLXBF_I2C_SMBUS_STATUS_NACK_RCV | \
+	 MLXBF_I2C_SMBUS_STATUS_READ_ERR | \
+	 MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT)
+
+#define MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK      BIT(31)
+#define MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK  BIT(15)
+
+/* SMBus slave GW. */
+#define MLXBF_I2C_SMBUS_SLAVE_GW              0x400
+/* Number of bytes received and sent from/to master. */
+#define MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES 0x500
+/* Packet error check (PEC) value. */
+#define MLXBF_I2C_SMBUS_SLAVE_PEC             0x504
+/* SMBus slave Finite State Machine (FSM). */
+#define MLXBF_I2C_SMBUS_SLAVE_FSM             0x510
+/*
+ * Should be set when all raised causes handled, and cleared by HW on
+ * every new cause.
+ */
+#define MLXBF_I2C_SMBUS_SLAVE_READY           0x52c
+
+/* SMBus slave GW control bits offset in MLXBF_I2C_SMBUS_SLAVE_GW[31:19]. */
+#define MLXBF_I2C_SLAVE_BUSY_BIT         BIT(30) /* Busy bit. */
+#define MLXBF_I2C_SLAVE_WRITE_BIT        BIT(29) /* Control write enable. */
+
+#define MLXBF_I2C_SLAVE_ENABLE \
+	(MLXBF_I2C_SLAVE_BUSY_BIT | MLXBF_I2C_SLAVE_WRITE_BIT)
+
+#define MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT 22 /* Number of bytes to write. */
+#define MLXBF_I2C_SLAVE_SEND_PEC_SHIFT    21 /* Send PEC byte shift. */
+
+/* SMBus slave GW Data descriptor. */
+#define MLXBF_I2C_SLAVE_DATA_DESC_ADDR   0x480
+#define MLXBF_I2C_SLAVE_DATA_DESC_SIZE   0x80 /* Size in bytes. */
+
+/* SMbus slave configuration registers. */
+#define MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG        0x514
+#define MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT        16
+#define MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT     7
+#define MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK       GENMASK(6, 0)
+
+#define MLXBF_I2C_SLAVE_ADDR_ENABLED(addr) \
+	((addr) & (1 << MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT))
+
+/*
+ * Timeout is given in microsends. Note also that timeout handling is not
+ * exact.
+ */
+#define MLXBF_I2C_SMBUS_TIMEOUT   (300 * 1000) /* 300ms */
+
+/* Encapsulates timing parameters. */
+struct mlxbf_i2c_timings {
+	u16 scl_high;		/* Clock high period. */
+	u16 scl_low;		/* Clock low period. */
+	u8 sda_rise;		/* Data rise time. */
+	u8 sda_fall;		/* Data fall time. */
+	u8 scl_rise;		/* Clock rise time. */
+	u8 scl_fall;		/* Clock fall time. */
+	u16 hold_start;		/* Hold time after (REPEATED) START. */
+	u16 hold_data;		/* Data hold time. */
+	u16 setup_start;	/* REPEATED START condition setup time. */
+	u16 setup_stop;		/* STOP condition setup time. */
+	u16 setup_data;		/* Data setup time. */
+	u16 pad;		/* Padding. */
+	u16 buf;		/* Bus free time between STOP and START. */
+	u16 thigh_max;		/* Thigh max. */
+	u32 timeout;		/* Detect clock low timeout. */
+};
+
+enum {
+	MLXBF_I2C_F_READ = BIT(0),
+	MLXBF_I2C_F_WRITE = BIT(1),
+	MLXBF_I2C_F_NORESTART = BIT(3),
+	MLXBF_I2C_F_SMBUS_OPERATION = BIT(4),
+	MLXBF_I2C_F_SMBUS_BLOCK = BIT(5),
+	MLXBF_I2C_F_SMBUS_PEC = BIT(6),
+	MLXBF_I2C_F_SMBUS_PROCESS_CALL = BIT(7),
+};
+
+struct mlxbf_i2c_smbus_operation {
+	u32 flags;
+	u32 length; /* Buffer length in bytes. */
+	u8 *buffer;
+};
+
+#define MLXBF_I2C_SMBUS_OP_CNT_1	1
+#define MLXBF_I2C_SMBUS_OP_CNT_2	2
+#define MLXBF_I2C_SMBUS_OP_CNT_3	3
+#define MLXBF_I2C_SMBUS_MAX_OP_CNT	MLXBF_I2C_SMBUS_OP_CNT_3
+
+struct mlxbf_i2c_smbus_request {
+	u8 slave;
+	u8 operation_cnt;
+	struct mlxbf_i2c_smbus_operation operation[MLXBF_I2C_SMBUS_MAX_OP_CNT];
+};
+
+struct mlxbf_i2c_resource {
+	void __iomem *io;
+	struct resource *params;
+	struct mutex *lock; /* Mutex to protect mlxbf_i2c_resource. */
+	u8 type;
+};
+
+/* List of chip resources that are being accessed by the driver. */
+enum {
+	MLXBF_I2C_SMBUS_RES,
+	MLXBF_I2C_MST_CAUSE_RES,
+	MLXBF_I2C_SLV_CAUSE_RES,
+	MLXBF_I2C_COALESCE_RES,
+	MLXBF_I2C_COREPLL_RES,
+	MLXBF_I2C_GPIO_RES,
+	MLXBF_I2C_END_RES,
+};
+
+/* Helper macro to define an I2C resource parameters. */
+#define MLXBF_I2C_RES_PARAMS(addr, size, str) \
+	{ \
+		.start = (addr), \
+		.end = (addr) + (size) - 1, \
+		.name = (str) \
+	}
+
+static struct resource mlxbf_i2c_coalesce_tyu_params =
+		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COALESCE_TYU_ADDR,
+				     MLXBF_I2C_COALESCE_TYU_SIZE,
+				     "COALESCE_MEM");
+static struct resource mlxbf_i2c_corepll_tyu_params =
+		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_TYU_ADDR,
+				     MLXBF_I2C_COREPLL_TYU_SIZE,
+				     "COREPLL_MEM");
+static struct resource mlxbf_i2c_corepll_yu_params =
+		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_YU_ADDR,
+				     MLXBF_I2C_COREPLL_YU_SIZE,
+				     "COREPLL_MEM");
+static struct resource mlxbf_i2c_gpio_tyu_params =
+		MLXBF_I2C_RES_PARAMS(MLXBF_I2C_GPIO_TYU_ADDR,
+				     MLXBF_I2C_GPIO_TYU_SIZE,
+				     "GPIO_MEM");
+
+static struct mutex mlxbf_i2c_coalesce_lock;
+static struct mutex mlxbf_i2c_corepll_lock;
+static struct mutex mlxbf_i2c_gpio_lock;
+
+/* Mellanox BlueField chip type. */
+enum mlxbf_i2c_chip_type {
+	MLXBF_I2C_CHIP_TYPE_1, /* Mellanox BlueField-1 chip. */
+	MLXBF_I2C_CHIP_TYPE_2, /* Mallanox BlueField-2 chip. */
+};
+
+struct mlxbf_i2c_chip_info {
+	enum mlxbf_i2c_chip_type type;
+	/* Chip shared resources that are being used by the I2C controller. */
+	struct mlxbf_i2c_resource *shared_res[MLXBF_I2C_SHARED_RES_MAX];
+
+	/* Callback to calculate the core PLL frequency. */
+	u64 (*calculate_freq)(struct mlxbf_i2c_resource *corepll_res);
+};
+
+struct mlxbf_i2c_priv {
+	const struct mlxbf_i2c_chip_info *chip;
+	struct i2c_adapter adap;
+	struct mlxbf_i2c_resource *smbus;
+	struct mlxbf_i2c_resource *mst_cause;
+	struct mlxbf_i2c_resource *slv_cause;
+	struct mlxbf_i2c_resource *coalesce;
+	u64 frequency; /* Core frequency in Hz. */
+	int bus; /* Physical bus identifier. */
+	int irq;
+	struct i2c_client *slave;
+};
+
+static struct mlxbf_i2c_resource mlxbf_i2c_coalesce_res[] = {
+	[MLXBF_I2C_CHIP_TYPE_1] = {
+		.params = &mlxbf_i2c_coalesce_tyu_params,
+		.lock = &mlxbf_i2c_coalesce_lock,
+		.type = MLXBF_I2C_COALESCE_RES
+	},
+	{}
+};
+
+static struct mlxbf_i2c_resource mlxbf_i2c_corepll_res[] = {
+	[MLXBF_I2C_CHIP_TYPE_1] = {
+		.params = &mlxbf_i2c_corepll_tyu_params,
+		.lock = &mlxbf_i2c_corepll_lock,
+		.type = MLXBF_I2C_COREPLL_RES
+	},
+	[MLXBF_I2C_CHIP_TYPE_2] = {
+		.params = &mlxbf_i2c_corepll_yu_params,
+		.lock = &mlxbf_i2c_corepll_lock,
+		.type = MLXBF_I2C_COREPLL_RES,
+	}
+};
+
+static struct mlxbf_i2c_resource mlxbf_i2c_gpio_res[] = {
+	[MLXBF_I2C_CHIP_TYPE_1] = {
+		.params = &mlxbf_i2c_gpio_tyu_params,
+		.lock = &mlxbf_i2c_gpio_lock,
+		.type = MLXBF_I2C_GPIO_RES
+	},
+	{}
+};
+
+static u8 mlxbf_i2c_bus_count;
+
+static struct mutex mlxbf_i2c_bus_lock;
+
+/* Polling frequency in microseconds. */
+#define MLXBF_I2C_POLL_FREQ_IN_USEC        200
+
+#define MLXBF_I2C_SHIFT_0   0
+#define MLXBF_I2C_SHIFT_8   8
+#define MLXBF_I2C_SHIFT_16  16
+#define MLXBF_I2C_SHIFT_24  24
+
+#define MLXBF_I2C_MASK_8    GENMASK(7, 0)
+#define MLXBF_I2C_MASK_16   GENMASK(15, 0)
+
+#define MLXBF_I2C_FREQUENCY_1GHZ  1000000000
+
+static void mlxbf_i2c_write(void __iomem *io, int reg, u32 val)
+{
+	writel(val, io + reg);
+}
+
+static u32 mlxbf_i2c_read(void __iomem *io, int reg)
+{
+	return readl(io + reg);
+}
+
+/*
+ * This function is used to read data from Master GW Data Descriptor.
+ * Data bytes in the Master GW Data Descriptor are shifted left so the
+ * data starts at the MSB of the descriptor registers as set by the
+ * underlying hardware. TYU_READ_DATA enables byte swapping while
+ * reading data bytes, and MUST be called by the SMBus read routines
+ * to copy data from the 32 * 32-bit HW Data registers a.k.a Master GW
+ * Data Descriptor.
+ */
+static u32 mlxbf_i2c_read_data(void __iomem *io, int reg)
+{
+	return (u32)be32_to_cpu(mlxbf_i2c_read(io, reg));
+}
+
+/*
+ * This function is used to write data to the Master GW Data Descriptor.
+ * Data copied to the Master GW Data Descriptor MUST be shifted left so
+ * the data starts at the MSB of the descriptor registers as required by
+ * the underlying hardware. TYU_WRITE_DATA enables byte swapping when
+ * writing data bytes, and MUST be called by the SMBus write routines to
+ * copy data to the 32 * 32-bit HW Data registers a.k.a Master GW Data
+ * Descriptor.
+ */
+static void mlxbf_i2c_write_data(void __iomem *io, int reg, u32 val)
+{
+	mlxbf_i2c_write(io, reg, (u32)cpu_to_be32(val));
+}
+
+/*
+ * Function to poll a set of bits at a specific address; it checks whether
+ * the bits are equal to zero when eq_zero is set to 'true', and not equal
+ * to zero when eq_zero is set to 'false'.
+ * Note that the timeout is given in microseconds.
+ */
+static u32 mlxbf_smbus_poll(void __iomem *io, u32 addr, u32 mask,
+			    bool eq_zero, u32  timeout)
+{
+	u32 bits;
+
+	timeout = (timeout / MLXBF_I2C_POLL_FREQ_IN_USEC) + 1;
+
+	do {
+		bits = mlxbf_i2c_read(io, addr) & mask;
+		if (eq_zero ? bits == 0 : bits != 0)
+			return eq_zero ? 1 : bits;
+		udelay(MLXBF_I2C_POLL_FREQ_IN_USEC);
+	} while (timeout-- != 0);
+
+	return 0;
+}
+
+/*
+ * SW must make sure that the SMBus Master GW is idle before starting
+ * a transaction. Accordingly, this function polls the Master FSM stop
+ * bit; it returns false when the bit is asserted, true if not.
+ */
+static bool mlxbf_smbus_master_wait_for_idle(struct mlxbf_i2c_priv *priv)
+{
+	u32 mask = MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK;
+	u32 addr = MLXBF_I2C_SMBUS_MASTER_FSM;
+	u32 timeout = MLXBF_I2C_SMBUS_TIMEOUT;
+
+	if (mlxbf_smbus_poll(priv->smbus->io, addr, mask, true, timeout))
+		return true;
+
+	return false;
+}
+
+static bool mlxbf_i2c_smbus_transaction_success(u32 master_status,
+						u32 cause_status)
+{
+	/*
+	 * When transaction ended with STOP, all bytes were transmitted,
+	 * and no NACK received, then the transaction ended successfully.
+	 * On the other hand, when the GW is configured with the stop bit
+	 * de-asserted then the SMBus expects the following GW configuration
+	 * for transfer continuation.
+	 */
+	if ((cause_status & MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA) ||
+	    ((cause_status & MLXBF_I2C_CAUSE_TRANSACTION_ENDED) &&
+	     (master_status & MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE) &&
+	     !(master_status & MLXBF_I2C_SMBUS_STATUS_NACK_RCV)))
+		return true;
+
+	return false;
+}
+
+/*
+ * Poll SMBus master status and return transaction status,
+ * i.e. whether succeeded or failed. I2C and SMBus fault codes
+ * are returned as negative numbers from most calls, with zero
+ * or some positive number indicating a non-fault return.
+ */
+static int mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv *priv)
+{
+	u32 master_status_bits;
+	u32 cause_status_bits;
+
+	/*
+	 * GW busy bit is raised by the driver and cleared by the HW
+	 * when the transaction is completed. The busy bit is a good
+	 * indicator of transaction status. So poll the busy bit, and
+	 * then read the cause and master status bits to determine if
+	 * errors occurred during the transaction.
+	 */
+	mlxbf_smbus_poll(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_GW,
+			 MLXBF_I2C_MASTER_BUSY_BIT, true,
+			 MLXBF_I2C_SMBUS_TIMEOUT);
+
+	/* Read cause status bits. */
+	cause_status_bits = mlxbf_i2c_read(priv->mst_cause->io,
+					   MLXBF_I2C_CAUSE_ARBITER);
+	cause_status_bits &= MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK;
+
+	/*
+	 * Parse both Cause and Master GW bits, then return transaction status.
+	 */
+
+	master_status_bits = mlxbf_i2c_read(priv->smbus->io,
+					    MLXBF_I2C_SMBUS_MASTER_STATUS);
+	master_status_bits &= MLXBF_I2C_SMBUS_MASTER_STATUS_MASK;
+
+	if (mlxbf_i2c_smbus_transaction_success(master_status_bits,
+						cause_status_bits))
+		return 0;
+
+	/*
+	 * In case of timeout on GW busy, the ISR will clear busy bit but
+	 * transaction ended bits cause will not be set so the transaction
+	 * fails. Then, we must check Master GW status bits.
+	 */
+	if ((master_status_bits & MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR) &&
+	    (cause_status_bits & (MLXBF_I2C_CAUSE_TRANSACTION_ENDED |
+				  MLXBF_I2C_CAUSE_M_GW_BUSY_FALL)))
+		return -EIO;
+
+	if (cause_status_bits & MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR)
+		return -EAGAIN;
+
+	return -ETIMEDOUT;
+}
+
+static void mlxbf_i2c_smbus_write_data(struct mlxbf_i2c_priv *priv,
+				       const u8 *data, u8 length, u32 addr)
+{
+	u8 offset, aligned_length;
+	u32 data32;
+
+	aligned_length = round_up(length, 4);
+
+	/* Copy data bytes from 4-byte aligned source buffer. */
+	for (offset = 0; offset < aligned_length; offset += sizeof(u32)) {
+		data32 = *((u32 *)(data + offset));
+		mlxbf_i2c_write_data(priv->smbus->io, addr + offset, data32);
+	}
+}
+
+static void mlxbf_i2c_smbus_read_data(struct mlxbf_i2c_priv *priv,
+				      u8 *data, u8 length, u32 addr)
+{
+	u32 data32, mask;
+	u8 byte, offset;
+
+	mask = sizeof(u32) - 1;
+
+	for (offset = 0; offset < (length & ~mask); offset += sizeof(u32)) {
+		data32 = mlxbf_i2c_read_data(priv->smbus->io, addr + offset);
+		*((u32 *)(data + offset)) = data32;
+	}
+
+	if (!(length & mask))
+		return;
+
+	data32 = mlxbf_i2c_read_data(priv->smbus->io, addr + offset);
+
+	for (byte = 0; byte < (length & mask); byte++) {
+		data[offset + byte] = data32 & GENMASK(7, 0);
+		data32 = ror32(data32, MLXBF_I2C_SHIFT_8);
+	}
+}
+
+static int mlxbf_i2c_smbus_enable(struct mlxbf_i2c_priv *priv, u8 slave,
+				  u8 len, u8 block_en, u8 pec_en, bool read)
+{
+	u32 command;
+
+	/* Set Master GW control word. */
+	if (read) {
+		command = MLXBF_I2C_MASTER_ENABLE_READ;
+		command |= rol32(len, MLXBF_I2C_MASTER_READ_SHIFT);
+	} else {
+		command = MLXBF_I2C_MASTER_ENABLE_WRITE;
+		command |= rol32(len, MLXBF_I2C_MASTER_WRITE_SHIFT);
+	}
+	command |= rol32(slave, MLXBF_I2C_MASTER_SLV_ADDR_SHIFT);
+	command |= rol32(block_en, MLXBF_I2C_MASTER_PARSE_EXP_SHIFT);
+	command |= rol32(pec_en, MLXBF_I2C_MASTER_SEND_PEC_SHIFT);
+
+	/* Clear status bits. */
+	mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_STATUS, 0x0);
+	/* Set the cause data. */
+	mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_CAUSE_OR_CLEAR, ~0x0);
+	/* Zero PEC byte. */
+	mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_PEC, 0x0);
+	/* Zero byte count. */
+	mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_RS_BYTES, 0x0);
+
+	/* GW activation. */
+	mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_GW, command);
+
+	/*
+	 * Poll master status and check status bits. An ACK is sent when
+	 * completing writing data to the bus (Master 'byte_count_done' bit
+	 * is set to 1).
+	 */
+	return mlxbf_i2c_smbus_check_status(priv);
+}
+
+static int
+mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv,
+				  struct mlxbf_i2c_smbus_request *request)
+{
+	u8 data_desc[MLXBF_I2C_MASTER_DATA_DESC_SIZE] = { 0 };
+	u8 op_idx, data_idx, data_len, write_len, read_len;
+	struct mlxbf_i2c_smbus_operation *operation;
+	u8 read_en, write_en, block_en, pec_en;
+	u8 slave, flags, addr;
+	u8 *read_buf;
+	int ret = 0;
+
+	if (request->operation_cnt > MLXBF_I2C_SMBUS_MAX_OP_CNT)
+		return -EINVAL;
+
+	read_buf = NULL;
+	data_idx = 0;
+	read_en = 0;
+	write_en = 0;
+	write_len = 0;
+	read_len = 0;
+	block_en = 0;
+	pec_en = 0;
+	slave = request->slave & GENMASK(6, 0);
+	addr = slave << 1;
+
+	/* First of all, check whether the HW is idle. */
+	if (WARN_ON(!mlxbf_smbus_master_wait_for_idle(priv)))
+		return -EBUSY;
+
+	/* Set first byte. */
+	data_desc[data_idx++] = addr;
+
+	for (op_idx = 0; op_idx < request->operation_cnt; op_idx++) {
+		operation = &request->operation[op_idx];
+		flags = operation->flags;
+
+		/*
+		 * Note that read and write operations might be handled by a
+		 * single command. If the MLXBF_I2C_F_SMBUS_OPERATION is set
+		 * then write command byte and set the optional SMBus specific
+		 * bits such as block_en and pec_en. These bits MUST be
+		 * submitted by the first operation only.
+		 */
+		if (op_idx == 0 && flags & MLXBF_I2C_F_SMBUS_OPERATION) {
+			block_en = flags & MLXBF_I2C_F_SMBUS_BLOCK;
+			pec_en = flags & MLXBF_I2C_F_SMBUS_PEC;
+		}
+
+		if (flags & MLXBF_I2C_F_WRITE) {
+			write_en = 1;
+			write_len += operation->length;
+			memcpy(data_desc + data_idx,
+			       operation->buffer, operation->length);
+			data_idx += operation->length;
+		}
+		/*
+		 * We assume that read operations are performed only once per
+		 * SMBus transaction. *TBD* protect this statement so it won't
+		 * be executed twice? or return an error if we try to read more
+		 * than once?
+		 */
+		if (flags & MLXBF_I2C_F_READ) {
+			read_en = 1;
+			/* Subtract 1 as required by HW. */
+			read_len = operation->length - 1;
+			read_buf = operation->buffer;
+		}
+	}
+
+	/* Set Master GW data descriptor. */
+	data_len = write_len + 1; /* Add one byte of the slave address. */
+	/*
+	 * Note that data_len cannot be 0. Indeed, the slave address byte
+	 * must be written to the data registers.
+	 */
+	mlxbf_i2c_smbus_write_data(priv, (const u8 *)data_desc, data_len,
+				   MLXBF_I2C_MASTER_DATA_DESC_ADDR);
+
+	if (write_en) {
+		ret = mlxbf_i2c_smbus_enable(priv, slave, write_len, block_en,
+					 pec_en, 0);
+		if (ret)
+			return ret;
+	}
+
+	if (read_en) {
+		/* Write slave address to Master GW data descriptor. */
+		mlxbf_i2c_smbus_write_data(priv, (const u8 *)&addr, 1,
+					   MLXBF_I2C_MASTER_DATA_DESC_ADDR);
+		ret = mlxbf_i2c_smbus_enable(priv, slave, read_len, block_en,
+					 pec_en, 1);
+		if (!ret) {
+			/* Get Master GW data descriptor. */
+			mlxbf_i2c_smbus_read_data(priv, data_desc, read_len + 1,
+					     MLXBF_I2C_MASTER_DATA_DESC_ADDR);
+
+			/* Get data from Master GW data descriptor. */
+			memcpy(read_buf, data_desc, read_len + 1);
+		}
+
+		/*
+		 * After a read operation the SMBus FSM ps (present state)
+		 * needs to be 'manually' reset. This should be removed in
+		 * next tag integration.
+		 */
+		mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_FSM,
+				MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK);
+	}
+
+	return ret;
+}
+
+/* I2C SMBus protocols. */
+
+static void
+mlxbf_i2c_smbus_quick_command(struct mlxbf_i2c_smbus_request *request,
+			      u8 read)
+{
+	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1;
+
+	request->operation[0].length = 0;
+	request->operation[0].flags = MLXBF_I2C_F_WRITE;
+	request->operation[0].flags |= read ? MLXBF_I2C_F_READ : 0;
+}
+
+static void mlxbf_i2c_smbus_byte_func(struct mlxbf_i2c_smbus_request *request,
+				      u8 *data, bool read, bool pec_check)
+{
+	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1;
+
+	request->operation[0].length = 1;
+	request->operation[0].length += pec_check;
+
+	request->operation[0].flags = MLXBF_I2C_F_SMBUS_OPERATION;
+	request->operation[0].flags |= read ?
+				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
+	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
+
+	request->operation[0].buffer = data;
+}
+
+static void
+mlxbf_i2c_smbus_data_byte_func(struct mlxbf_i2c_smbus_request *request,
+			       u8 *command, u8 *data, bool read, bool pec_check)
+{
+	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
+
+	request->operation[0].length = 1;
+	request->operation[0].flags =
+			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
+	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
+	request->operation[0].buffer = command;
+
+	request->operation[1].length = 1;
+	request->operation[1].length += pec_check;
+	request->operation[1].flags = read ?
+				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
+	request->operation[1].buffer = data;
+}
+
+static void
+mlxbf_i2c_smbus_data_word_func(struct mlxbf_i2c_smbus_request *request,
+			       u8 *command, u8 *data, bool read, bool pec_check)
+{
+	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
+
+	request->operation[0].length = 1;
+	request->operation[0].flags =
+			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
+	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
+	request->operation[0].buffer = command;
+
+	request->operation[1].length = 2;
+	request->operation[1].length += pec_check;
+	request->operation[1].flags = read ?
+				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
+	request->operation[1].buffer = data;
+}
+
+static void
+mlxbf_i2c_smbus_i2c_block_func(struct mlxbf_i2c_smbus_request *request,
+			       u8 *command, u8 *data, u8 *data_len, bool read,
+			       bool pec_check)
+{
+	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
+
+	request->operation[0].length = 1;
+	request->operation[0].flags =
+			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
+	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
+	request->operation[0].buffer = command;
+
+	/*
+	 * As specified in the standard, the max number of bytes to read/write
+	 * per block operation is 32 bytes. In Golan code, the controller can
+	 * read up to 128 bytes and write up to 127 bytes.
+	 */
+	request->operation[1].length =
+	    (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
+	    I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
+	request->operation[1].flags = read ?
+				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
+	/*
+	 * Skip the first data byte, which corresponds to the number of bytes
+	 * to read/write.
+	 */
+	request->operation[1].buffer = data + 1;
+
+	*data_len = request->operation[1].length;
+
+	/* Set the number of byte to read. This will be used by userspace. */
+	if (read)
+		data[0] = *data_len;
+}
+
+static void mlxbf_i2c_smbus_block_func(struct mlxbf_i2c_smbus_request *request,
+				       u8 *command, u8 *data, u8 *data_len,
+				       bool read, bool pec_check)
+{
+	request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2;
+
+	request->operation[0].length = 1;
+	request->operation[0].flags =
+			MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE;
+	request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK;
+	request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0;
+	request->operation[0].buffer = command;
+
+	request->operation[1].length =
+	    (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
+	    I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
+	request->operation[1].flags = read ?
+				MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE;
+	request->operation[1].buffer = data + 1;
+
+	*data_len = request->operation[1].length;
+
+	/* Set the number of bytes to read. This will be used by userspace. */
+	if (read)
+		data[0] = *data_len;
+}
+
+static void
+mlxbf_i2c_smbus_process_call_func(struct mlxbf_i2c_smbus_request *request,
+