// SPDX-License-Identifier: GPL-2.0
/*
* Mellanox BlueField I2C bus driver
*
* Copyright ( C ) 2020 Mellanox Technologies , Ltd .
*/
#include <linux/acpi.h>
#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/string.h>
#include <linux/string_choices.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)
/* Shared resources info in BlueField platforms. */
#define MLXBF_I2C_COALESCE_TYU_ADDR 0 x02801300
#define MLXBF_I2C_COALESCE_TYU_SIZE 0 x010
#define MLXBF_I2C_GPIO_TYU_ADDR 0 x02802000
#define MLXBF_I2C_GPIO_TYU_SIZE 0 x100
#define MLXBF_I2C_COREPLL_TYU_ADDR 0 x02800358
#define MLXBF_I2C_COREPLL_TYU_SIZE 0 x008
#define MLXBF_I2C_COREPLL_YU_ADDR 0 x02800c30
#define MLXBF_I2C_COREPLL_YU_SIZE 0 x00c
#define MLXBF_I2C_COREPLL_RSH_YU_ADDR 0 x13409824
#define MLXBF_I2C_COREPLL_RSH_YU_SIZE 0 x00c
#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 400 MHz .
*/
#define MLXBF_I2C_TYU_PLL_OUT_FREQ (400 * 1000 * 1000 )
/* Reference clock for Bluefield - 156 MHz. */
#define MLXBF_I2C_PLL_IN_FREQ 156250000 ULL
/* Constant used to determine the PLL frequency. */
#define MLNXBF_I2C_COREPLL_CONST 16384 ULL
#define MLXBF_I2C_FREQUENCY_1GHZ 1000000000 ULL
/* PLL registers. */
#define MLXBF_I2C_CORE_PLL_REG1 0 x4
#define MLXBF_I2C_CORE_PLL_REG2 0 x8
/* OR cause register. */
#define MLXBF_I2C_CAUSE_OR_EVTEN0 0 x14
#define MLXBF_I2C_CAUSE_OR_CLEAR 0 x18
/* Arbiter Cause Register. */
#define MLXBF_I2C_CAUSE_ARBITER 0 x1c
/*
* 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 )
/* Cause coalesce registers. */
#define MLXBF_I2C_CAUSE_COALESCE_0 0 x00
#define MLXBF_I2C_CAUSE_TYU_SLAVE_BIT 3
#define MLXBF_I2C_CAUSE_YU_SLAVE_BIT 1
/* Functional enable register. */
#define MLXBF_I2C_GPIO_0_FUNC_EN_0 0 x28
/* Force OE enable register. */
#define MLXBF_I2C_GPIO_0_FORCE_OE_EN 0 x30
/*
* 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) \
(0 xffffffff & (~(0 x3 << 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) | (0 x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num)))
/*
* Defines SMBus operating frequency and core clock frequency .
* According to ADB files , default values are compliant to 100 KHz SMBus
* @ 400 MHz 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(15 , 3 )
#define MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK GENMASK(19 , 16 )
#define MLXBF_I2C_COREPLL_CORE_R_TYU_MASK GENMASK(25 , 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(31 , 26 )
/* SMBus timing parameters. */
#define MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH 0 x00
#define MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE 0 x04
#define MLXBF_I2C_SMBUS_TIMER_THOLD 0 x08
#define MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP 0 x0c
#define MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA 0 x10
#define MLXBF_I2C_SMBUS_THIGH_MAX_TBUF 0 x14
#define MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT 0 x18
#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_MASK_32 GENMASK(31 , 0 )
#define MLXBF_I2C_MST_ADDR_OFFSET 0 x200
/* SMBus Master GW. */
#define MLXBF_I2C_SMBUS_MASTER_GW 0 x0
/* Number of bytes received and sent. */
#define MLXBF_I2C_YU_SMBUS_RS_BYTES 0 x100
#define MLXBF_I2C_RSH_YU_SMBUS_RS_BYTES 0 x10c
/* Packet error check (PEC) value. */
#define MLXBF_I2C_SMBUS_MASTER_PEC 0 x104
/* Status bits (ACK/NACK/FW Timeout). */
#define MLXBF_I2C_SMBUS_MASTER_STATUS 0 x108
/* SMbus Master Finite State Machine. */
#define MLXBF_I2C_YU_SMBUS_MASTER_FSM 0 x110
#define MLXBF_I2C_RSH_YU_SMBUS_MASTER_FSM 0 x100
/* 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)
#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_WRITE_SHIFT 21 /* Control write bytes */
#define MLXBF_I2C_MASTER_SEND_PEC_SHIFT 20 /* Send PEC byte when set to 1 */
#define MLXBF_I2C_MASTER_PARSE_EXP_SHIFT 11 /* Control parse expected bytes */
#define MLXBF_I2C_MASTER_SLV_ADDR_SHIFT 12 /* Slave address */
#define MLXBF_I2C_MASTER_READ_SHIFT 4 /* Control read bytes */
/* SMBus master GW Data descriptor. */
#define MLXBF_I2C_MASTER_DATA_DESC_ADDR 0 x80
#define MLXBF_I2C_MASTER_DATA_DESC_SIZE 0 x80 /* 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 )
#define MLXBF_I2C_SLV_ADDR_OFFSET 0 x400
/* SMBus slave GW. */
#define MLXBF_I2C_SMBUS_SLAVE_GW 0 x0
/* Number of bytes received and sent from/to master. */
#define MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES 0 x100
/* Packet error check (PEC) value. */
#define MLXBF_I2C_SMBUS_SLAVE_PEC 0 x104
/* SMBus slave Finite State Machine (FSM). */
#define MLXBF_I2C_SMBUS_SLAVE_FSM 0 x110
/*
* Should be set when all raised causes handled , and cleared by HW on
* every new cause .
*/
#define MLXBF_I2C_SMBUS_SLAVE_READY 0 x12c
/* 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 0 x80
#define MLXBF_I2C_SLAVE_DATA_DESC_SIZE 0 x80 /* Size in bytes. */
/* SMbus slave configuration registers. */
#define MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG 0 x114
#define MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT 16
#define MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT BIT(7 )
#define MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK GENMASK(6 , 0 )
/*
* Timeout is given in microsends . Note also that timeout handling is not
* exact .
*/
#define MLXBF_I2C_SMBUS_TIMEOUT (300 * 1000 ) /* 300ms */
#define MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT (300 * 1000 ) /* 300ms */
/* Polling frequency in microseconds. */
#define MLXBF_I2C_POLL_FREQ_IN_USEC 200
#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
/* Helper macro to define an I2C resource parameters. */
#define MLXBF_I2C_RES_PARAMS(addr, size, str) \
{ \
.start = (addr), \
.end = (addr) + (size) - 1 , \
.name = (str) \
}
enum {
MLXBF_I2C_TIMING_100KHZ = 100000 ,
MLXBF_I2C_TIMING_400KHZ = 400000 ,
MLXBF_I2C_TIMING_1000KHZ = 1000000 ,
};
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 ),
MLXBF_I2C_F_WRITE_WITHOUT_STOP = BIT(8 ),
};
/* Mellanox BlueField chip type. */
enum mlxbf_i2c_chip_type {
MLXBF_I2C_CHIP_TYPE_1, /* Mellanox BlueField-1 chip. */
MLXBF_I2C_CHIP_TYPE_2, /* Mellanox BlueField-2 chip. */
MLXBF_I2C_CHIP_TYPE_3 /* Mellanox BlueField-3 chip. */
};
/* 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_SMBUS_TIMER_RES,
MLXBF_I2C_SMBUS_MST_RES,
MLXBF_I2C_SMBUS_SLV_RES,
MLXBF_I2C_COREPLL_RES,
MLXBF_I2C_GPIO_RES,
MLXBF_I2C_END_RES
};
/* 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. */
};
struct mlxbf_i2c_smbus_operation {
u32 flags;
u32 length; /* Buffer length in bytes. */
u8 *buffer;
};
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;
};
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);
/* Registers' address offset */
u32 smbus_master_rs_bytes_off;
u32 smbus_master_fsm_off;
};
struct mlxbf_i2c_priv {
const struct mlxbf_i2c_chip_info *chip;
struct i2c_adapter adap;
struct mlxbf_i2c_resource *smbus;
struct mlxbf_i2c_resource *timer;
struct mlxbf_i2c_resource *mst;
struct mlxbf_i2c_resource *slv;
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[MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT];
u32 resource_version;
};
/* Core PLL frequency. */
static u64 mlxbf_i2c_corepll_frequency;
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_corepll_rsh_yu_params =
MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_RSH_YU_ADDR,
MLXBF_I2C_COREPLL_RSH_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;
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,
},
[MLXBF_I2C_CHIP_TYPE_3] = {
.params = &mlxbf_i2c_corepll_rsh_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;
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;
u32 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 .
*/
readl_poll_timeout_atomic(priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW,
bits, !(bits & MLXBF_I2C_MASTER_BUSY_BIT),
MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT);
/* Read cause status bits. */
cause_status_bits = readl(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 = readl(priv->mst->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,
bool is_master)
{
u8 offset, aligned_length;
u32 data32;
aligned_length = round_up(length, 4 );
/*
* Copy data bytes from 4 - byte aligned source buffer .
* 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 . Enable byte swapping
* when writing data bytes to the 32 * 32 - bit HW Data registers
* a . k . a Master GW Data Descriptor .
*/
for (offset = 0 ; offset < aligned_length; offset += sizeof (u32)) {
data32 = *((u32 *)(data + offset));
if (is_master)
iowrite32be(data32, priv->mst->io + addr + offset);
else
iowrite32be(data32, priv->slv->io + addr + offset);
}
}
static void mlxbf_i2c_smbus_read_data(struct mlxbf_i2c_priv *priv,
u8 *data, u8 length, u32 addr,
bool is_master)
{
u32 data32, mask;
u8 byte, offset;
mask = sizeof (u32) - 1 ;
/*
* 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 . Enable byte swapping while
* reading data bytes from the 32 * 32 - bit HW Data registers
* a . k . a Master GW Data Descriptor .
*/
for (offset = 0 ; offset < (length & ~mask); offset += sizeof (u32)) {
if (is_master)
data32 = ioread32be(priv->mst->io + addr + offset);
else
data32 = ioread32be(priv->slv->io + addr + offset);
*((u32 *)(data + offset)) = data32;
}
if (!(length & mask))
return ;
if (is_master)
data32 = ioread32be(priv->mst->io + addr + offset);
else
data32 = ioread32be(priv->slv->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,
bool stop)
{
u32 command = 0 ;
/* Set Master GW control word. */
if (stop)
command |= MLXBF_I2C_MASTER_STOP_BIT;
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. */
writel(0 x0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_STATUS);
/* Set the cause data. */
writel(~0 x0, priv->mst_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
/* Zero PEC byte. */
writel(0 x0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_PEC);
/* Zero byte count. */
writel(0 x0, priv->mst->io + priv->chip->smbus_master_rs_bytes_off);
/* GW activation. */
writel(command, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW);
/*
* 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;
bool stop_after_write = true ;
u8 slave, addr;
u8 *read_buf;
u32 flags;
u32 bits;
int ret;
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 ;
/*
* Try to acquire the smbus gw lock before any reads of the GW register since
* a read sets the lock .
*/
ret = readl_poll_timeout_atomic(priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW,
bits, !(bits & MLXBF_I2C_MASTER_LOCK_BIT),
MLXBF_I2C_POLL_FREQ_IN_USEC,
MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT);
if (WARN_ON(ret))
return -EBUSY;
/*
* SW must make sure that the SMBus Master GW is idle before starting
* a transaction . Accordingly , this call polls the Master FSM stop bit ;
* it returns - ETIMEDOUT when the bit is asserted , 0 if not .
*/
ret = readl_poll_timeout_atomic(priv->mst->io + priv->chip->smbus_master_fsm_off,
bits, !(bits & MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK),
MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT);
if (WARN_ON(ret)) {
ret = -EBUSY;
goto out_unlock;
}
/* 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;
if (data_idx + operation->length >
MLXBF_I2C_MASTER_DATA_DESC_SIZE) {
ret = -ENOBUFS;
goto out_unlock;
}
memcpy(data_desc + data_idx,
operation->buffer, operation->length);
data_idx += operation->length;
/*
* The stop condition can be skipped when writing on the bus
* to implement a repeated start condition on the next read
* as required for several SMBus and I2C operations .
*/
if (flags & MLXBF_I2C_F_WRITE_WITHOUT_STOP)
stop_after_write = false ;
}
/*
* 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, true );
if (write_en) {
ret = mlxbf_i2c_smbus_enable(priv, slave, write_len, block_en,
pec_en, 0 , stop_after_write);
if (ret)
goto out_unlock;
}
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, true );
ret = mlxbf_i2c_smbus_enable(priv, slave, read_len, block_en,
pec_en, 1 , true );
if (!ret) {
/* Get Master GW data descriptor. */
mlxbf_i2c_smbus_read_data(priv, data_desc, read_len + 1 ,
MLXBF_I2C_MASTER_DATA_DESC_ADDR, true );
/* 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 .
*/
writel(MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK,
priv->mst->io + priv->chip->smbus_master_fsm_off);
}
out_unlock:
/* Clear the gw to clear the lock */
writel(0 , priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW);
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;
if (read)
request->operation[0 ].flags |= MLXBF_I2C_F_WRITE_WITHOUT_STOP;
/*
* 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,
u8 *command, u8 *data, bool pec_check)
{
request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3;
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 = 2 ;
request->operation[1 ].flags = MLXBF_I2C_F_WRITE;
request->operation[1 ].buffer = data;
request->operation[2 ].length = 3 ;
request->operation[2 ].flags = MLXBF_I2C_F_READ;
request->operation[2 ].buffer = data;
}
static void
mlxbf_i2c_smbus_blk_process_call_func(struct mlxbf_i2c_smbus_request *request,
u8 *command, u8 *data, u8 *data_len,
bool pec_check)
{
u32 length;
request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3;
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;
length = (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ?
I2C_SMBUS_BLOCK_MAX : *data_len + pec_check;
request->operation[1 ].length = length - pec_check;
request->operation[1 ].flags = MLXBF_I2C_F_WRITE;
request->operation[1 ].buffer = data;
request->operation[2 ].length = length;
request->operation[2 ].flags = MLXBF_I2C_F_READ;
request->operation[2 ].buffer = data;
*data_len = length; /* including PEC byte. */
}
/* Initialization functions. */
static bool mlxbf_i2c_has_chip_type(struct mlxbf_i2c_priv *priv, u8 type)
{
return priv->chip->type == type;
}
static struct mlxbf_i2c_resource *
mlxbf_i2c_get_shared_resource(struct mlxbf_i2c_priv *priv, u8 type)
{
const struct mlxbf_i2c_chip_info *chip = priv->chip;
struct mlxbf_i2c_resource *res;
u8 res_idx = 0 ;
for (res_idx = 0 ; res_idx < MLXBF_I2C_SHARED_RES_MAX; res_idx++) {
res = chip->shared_res[res_idx];
if (res && res->type == type)
return res;
}
return NULL;
}
static int mlxbf_i2c_init_resource(struct platform_device *pdev,
struct mlxbf_i2c_resource **res,
u8 type)
{
struct mlxbf_i2c_resource *tmp_res;
struct device *dev = &pdev->dev;
if (!res || *res || type >= MLXBF_I2C_END_RES)
return -EINVAL;
tmp_res = devm_kzalloc(dev, sizeof (struct mlxbf_i2c_resource),
GFP_KERNEL);
if (!tmp_res)
return -ENOMEM;
tmp_res->io = devm_platform_get_and_ioremap_resource(pdev, type, &tmp_res->params);
if (IS_ERR(tmp_res->io)) {
devm_kfree(dev, tmp_res);
return PTR_ERR(tmp_res->io);
}
tmp_res->type = type;
*res = tmp_res;
return 0 ;
}
static u32 mlxbf_i2c_get_ticks(struct mlxbf_i2c_priv *priv, u64 nanoseconds,
bool minimum)
{
u64 frequency;
u32 ticks;
/*
* Compute ticks as follow :
*
* Ticks
* Time = - - - - - - - - - x 10 ^ 9 = > Ticks = Time x Frequency x 10 ^ - 9
* Frequency
*/
frequency = priv->frequency;
ticks = div_u64(nanoseconds * frequency, MLXBF_I2C_FREQUENCY_1GHZ);
/*
* The number of ticks is rounded down and if minimum is equal to 1
* then add one tick .
*/
if (minimum)
ticks++;
return ticks;
}
static u32 mlxbf_i2c_set_timer(struct mlxbf_i2c_priv *priv, u64 nsec, bool opt,
u32 mask, u8 shift)
{
u32 val = (mlxbf_i2c_get_ticks(priv, nsec, opt) & mask) << shift;
return val;
}
static void mlxbf_i2c_set_timings(struct mlxbf_i2c_priv *priv,
const struct mlxbf_i2c_timings *timings)
{
u32 timer;
timer = mlxbf_i2c_set_timer(priv, timings->scl_high,
false , MLXBF_I2C_MASK_16,
MLXBF_I2C_SHIFT_0);
timer |= mlxbf_i2c_set_timer(priv, timings->scl_low,
false , MLXBF_I2C_MASK_16,
MLXBF_I2C_SHIFT_16);
writel(timer, priv->timer->io +
MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH);
timer = mlxbf_i2c_set_timer(priv, timings->sda_rise, false ,
MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_0);
timer |= mlxbf_i2c_set_timer(priv, timings->sda_fall, false ,
MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_8);
timer |= mlxbf_i2c_set_timer(priv, timings->scl_rise, false ,
MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_16);
timer |= mlxbf_i2c_set_timer(priv, timings->scl_fall, false ,
MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_24);
writel(timer, priv->timer->io +
MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE);
timer = mlxbf_i2c_set_timer(priv, timings->hold_start, true ,
MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
timer |= mlxbf_i2c_set_timer(priv, timings->hold_data, true ,
MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_TIMER_THOLD);
timer = mlxbf_i2c_set_timer(priv, timings->setup_start, true ,
MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
timer |= mlxbf_i2c_set_timer(priv, timings->setup_stop, true ,
MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
writel(timer, priv->timer->io +
MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP);
timer = mlxbf_i2c_set_timer(priv, timings->setup_data, true ,
MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA);
timer = mlxbf_i2c_set_timer(priv, timings->buf, false ,
MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0);
timer |= mlxbf_i2c_set_timer(priv, timings->thigh_max, false ,
MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16);
writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_THIGH_MAX_TBUF);
timer = mlxbf_i2c_set_timer(priv, timings->timeout, false ,
MLXBF_I2C_MASK_32, MLXBF_I2C_SHIFT_0);
writel(timer, priv->timer->io + MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT);
}
enum mlxbf_i2c_timings_config {
MLXBF_I2C_TIMING_CONFIG_100KHZ,
MLXBF_I2C_TIMING_CONFIG_400KHZ,
MLXBF_I2C_TIMING_CONFIG_1000KHZ,
};
/* Timing values are in nanoseconds */
static const struct mlxbf_i2c_timings mlxbf_i2c_timings[] = {
[MLXBF_I2C_TIMING_CONFIG_100KHZ] = {
.scl_high = 4810 ,
.scl_low = 5000 ,
.hold_start = 4000 ,
.setup_start = 4800 ,
.setup_stop = 4000 ,
.setup_data = 250 ,
.sda_rise = 50 ,
.sda_fall = 50 ,
.scl_rise = 50 ,
.scl_fall = 50 ,
.hold_data = 300 ,
.buf = 20000 ,
.thigh_max = 50000 ,
.timeout = 35000000
},
[MLXBF_I2C_TIMING_CONFIG_400KHZ] = {
.scl_high = 1011 ,
.scl_low = 1300 ,
.hold_start = 600 ,
.setup_start = 700 ,
.setup_stop = 600 ,
.setup_data = 100 ,
.sda_rise = 50 ,
.sda_fall = 50 ,
.scl_rise = 50 ,
.scl_fall = 50 ,
.hold_data = 300 ,
.buf = 20000 ,
.thigh_max = 50000 ,
.timeout = 35000000
},
[MLXBF_I2C_TIMING_CONFIG_1000KHZ] = {
.scl_high = 383 ,
.scl_low = 460 ,
.hold_start = 600 ,
.setup_start = 260 ,
.setup_stop = 260 ,
.setup_data = 50 ,
.sda_rise = 50 ,
.sda_fall = 50 ,
.scl_rise = 50 ,
.scl_fall = 50 ,
.hold_data = 300 ,
.buf = 500 ,
.thigh_max = 50000 ,
.timeout = 35000000
}
};
static int mlxbf_i2c_init_timings(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
enum mlxbf_i2c_timings_config config_idx;
struct device *dev = &pdev->dev;
u32 config_khz;
int ret;
ret = device_property_read_u32(dev, "clock-frequency" , &config_khz);
if (ret < 0 )
config_khz = I2C_MAX_STANDARD_MODE_FREQ;
switch (config_khz) {
default :
/* Default settings is 100 KHz. */
pr_warn("Illegal value %d: defaulting to 100 KHz\n" ,
config_khz);
fallthrough;
case I2C_MAX_STANDARD_MODE_FREQ:
config_idx = MLXBF_I2C_TIMING_CONFIG_100KHZ;
break ;
case I2C_MAX_FAST_MODE_FREQ:
config_idx = MLXBF_I2C_TIMING_CONFIG_400KHZ;
break ;
case I2C_MAX_FAST_MODE_PLUS_FREQ:
config_idx = MLXBF_I2C_TIMING_CONFIG_1000KHZ;
break ;
}
mlxbf_i2c_set_timings(priv, &mlxbf_i2c_timings[config_idx]);
return 0 ;
}
static int mlxbf_i2c_get_gpio(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
struct mlxbf_i2c_resource *gpio_res;
struct device *dev = &pdev->dev;
struct resource *params;
resource_size_t size;
gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
if (!gpio_res)
return -EPERM;
/*
* The GPIO region in TYU space is shared among I2C busses .
* This function MUST be serialized to avoid racing when
* claiming the memory region and / or setting up the GPIO .
*/
lockdep_assert_held(gpio_res->lock);
/* Check whether the memory map exist. */
if (gpio_res->io)
return 0 ;
params = gpio_res->params;
size = resource_size(params);
if (!devm_request_mem_region(dev, params->start, size, params->name))
return -EFAULT;
gpio_res->io = devm_ioremap(dev, params->start, size);
if (!gpio_res->io) {
devm_release_mem_region(dev, params->start, size);
return -ENOMEM;
}
return 0 ;
}
static int mlxbf_i2c_release_gpio(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
struct mlxbf_i2c_resource *gpio_res;
struct device *dev = &pdev->dev;
struct resource *params;
gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
if (!gpio_res)
return 0 ;
mutex_lock(gpio_res->lock);
if (gpio_res->io) {
/* Release the GPIO resource. */
params = gpio_res->params;
devm_iounmap(dev, gpio_res->io);
devm_release_mem_region(dev, params->start,
resource_size(params));
}
mutex_unlock(gpio_res->lock);
return 0 ;
}
static int mlxbf_i2c_get_corepll(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
struct mlxbf_i2c_resource *corepll_res;
struct device *dev = &pdev->dev;
struct resource *params;
resource_size_t size;
corepll_res = mlxbf_i2c_get_shared_resource(priv,
MLXBF_I2C_COREPLL_RES);
if (!corepll_res)
return -EPERM;
/*
* The COREPLL region in TYU space is shared among I2C busses .
* This function MUST be serialized to avoid racing when
* claiming the memory region .
*/
lockdep_assert_held(corepll_res->lock);
/* Check whether the memory map exist. */
if (corepll_res->io)
return 0 ;
params = corepll_res->params;
size = resource_size(params);
if (!devm_request_mem_region(dev, params->start, size, params->name))
return -EFAULT;
corepll_res->io = devm_ioremap(dev, params->start, size);
if (!corepll_res->io) {
devm_release_mem_region(dev, params->start, size);
return -ENOMEM;
}
return 0 ;
}
static int mlxbf_i2c_release_corepll(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
struct mlxbf_i2c_resource *corepll_res;
struct device *dev = &pdev->dev;
struct resource *params;
corepll_res = mlxbf_i2c_get_shared_resource(priv,
MLXBF_I2C_COREPLL_RES);
mutex_lock(corepll_res->lock);
if (corepll_res->io) {
/* Release the CorePLL resource. */
params = corepll_res->params;
devm_iounmap(dev, corepll_res->io);
devm_release_mem_region(dev, params->start,
resource_size(params));
}
mutex_unlock(corepll_res->lock);
return 0 ;
}
static int mlxbf_i2c_init_master(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
struct mlxbf_i2c_resource *gpio_res;
struct device *dev = &pdev->dev;
u32 config_reg;
int ret;
/* This configuration is only needed for BlueField 1. */
if (!mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1))
return 0 ;
gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES);
if (!gpio_res)
return -EPERM;
/*
* The GPIO region in TYU space is shared among I2C busses .
* This function MUST be serialized to avoid racing when
* claiming the memory region and / or setting up the GPIO .
*/
mutex_lock(gpio_res->lock);
ret = mlxbf_i2c_get_gpio(pdev, priv);
if (ret < 0 ) {
dev_err(dev, "Failed to get gpio resource" );
mutex_unlock(gpio_res->lock);
return ret;
}
/*
* TYU - Configuration for GPIO pins . Those pins must be asserted in
* MLXBF_I2C_GPIO_0_FUNC_EN_0 , i . e . GPIO 0 is controlled by HW , and must
* be reset in MLXBF_I2C_GPIO_0_FORCE_OE_EN , i . e . GPIO_OE will be driven
* instead of HW_OE .
* For now , we do not reset the GPIO state when the driver is removed .
* First , it is not necessary to disable the bus since we are using
* the same busses . Then , some busses might be shared among Linux and
* platform firmware ; disabling the bus might compromise the system
* functionality .
*/
config_reg = readl(gpio_res->io + MLXBF_I2C_GPIO_0_FUNC_EN_0);
config_reg = MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(priv->bus,
config_reg);
writel(config_reg, gpio_res->io + MLXBF_I2C_GPIO_0_FUNC_EN_0);
config_reg = readl(gpio_res->io + MLXBF_I2C_GPIO_0_FORCE_OE_EN);
config_reg = MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(priv->bus,
config_reg);
writel(config_reg, gpio_res->io + MLXBF_I2C_GPIO_0_FORCE_OE_EN);
mutex_unlock(gpio_res->lock);
return 0 ;
}
static u64 mlxbf_i2c_calculate_freq_from_tyu(struct mlxbf_i2c_resource *corepll_res)
{
u64 core_frequency;
u8 core_od, core_r;
u32 corepll_val;
u16 core_f;
corepll_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
/* Get Core PLL configuration bits. */
core_f = FIELD_GET(MLXBF_I2C_COREPLL_CORE_F_TYU_MASK, corepll_val);
core_od = FIELD_GET(MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK, corepll_val);
core_r = FIELD_GET(MLXBF_I2C_COREPLL_CORE_R_TYU_MASK, corepll_val);
/*
* Compute PLL output frequency as follow :
*
* CORE_F + 1
* PLL_OUT_FREQ = PLL_IN_FREQ * - - - - - - - - - - - - - - - - - - - - - - - - - - - -
* ( CORE_R + 1 ) * ( CORE_OD + 1 )
*
* Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency
* and PadFrequency , respectively .
*/
core_frequency = MLXBF_I2C_PLL_IN_FREQ * (++core_f);
return div_u64(core_frequency, (++core_r) * (++core_od));
}
static u64 mlxbf_i2c_calculate_freq_from_yu(struct mlxbf_i2c_resource *corepll_res)
{
u32 corepll_reg1_val, corepll_reg2_val;
u64 corepll_frequency;
u8 core_od, core_r;
u32 core_f;
corepll_reg1_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
corepll_reg2_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG2);
/* Get Core PLL configuration bits */
core_f = FIELD_GET(MLXBF_I2C_COREPLL_CORE_F_YU_MASK, corepll_reg1_val);
core_r = FIELD_GET(MLXBF_I2C_COREPLL_CORE_R_YU_MASK, corepll_reg1_val);
core_od = FIELD_GET(MLXBF_I2C_COREPLL_CORE_OD_YU_MASK, corepll_reg2_val);
/*
* Compute PLL output frequency as follow :
*
* CORE_F / 16384
* PLL_OUT_FREQ = PLL_IN_FREQ * - - - - - - - - - - - - - - - - - - - - - - - - - - - -
* ( CORE_R + 1 ) * ( CORE_OD + 1 )
*
* Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency
* and PadFrequency , respectively .
*/
corepll_frequency = (MLXBF_I2C_PLL_IN_FREQ * core_f) / MLNXBF_I2C_COREPLL_CONST;
return div_u64(corepll_frequency, (++core_r) * (++core_od));
}
static int mlxbf_i2c_calculate_corepll_freq(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
const struct mlxbf_i2c_chip_info *chip = priv->chip;
struct mlxbf_i2c_resource *corepll_res;
struct device *dev = &pdev->dev;
u64 *freq = &priv->frequency;
int ret;
corepll_res = mlxbf_i2c_get_shared_resource(priv,
MLXBF_I2C_COREPLL_RES);
if (!corepll_res)
return -EPERM;
/*
* First , check whether the TYU core Clock frequency is set .
* The TYU core frequency is the same for all I2C busses ; when
* the first device gets probed the frequency is determined and
* stored into a globally visible variable . So , first of all ,
* check whether the frequency is already set . Here , we assume
* that the frequency is expected to be greater than 0 .
*/
mutex_lock(corepll_res->lock);
if (!mlxbf_i2c_corepll_frequency) {
if (!chip->calculate_freq) {
mutex_unlock(corepll_res->lock);
return -EPERM;
}
ret = mlxbf_i2c_get_corepll(pdev, priv);
if (ret < 0 ) {
dev_err(dev, "Failed to get corePLL resource" );
mutex_unlock(corepll_res->lock);
return ret;
}
mlxbf_i2c_corepll_frequency = chip->calculate_freq(corepll_res);
}
mutex_unlock(corepll_res->lock);
*freq = mlxbf_i2c_corepll_frequency;
return 0 ;
}
static int mlxbf_i2c_slave_enable(struct mlxbf_i2c_priv *priv,
struct i2c_client *slave)
{
u8 reg, reg_cnt, byte, addr_tmp;
u32 slave_reg, slave_reg_tmp;
if (!priv)
return -EPERM;
reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2 ;
/*
* Read the slave registers . There are 4 * 32 - bit slave registers .
* Each slave register can hold up to 4 * 8 - bit slave configuration :
* 1 ) A 7 - bit address
* 2 ) And a status bit ( 1 if enabled , 0 if not ) .
* Look for the next available slave register slot .
*/
for (reg = 0 ; reg < reg_cnt; reg++) {
slave_reg = readl(priv->slv->io +
MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0 x4);
/*
* Each register holds 4 slave addresses . So , we have to keep
* the byte order consistent with the value read in order to
* update the register correctly , if needed .
*/
slave_reg_tmp = slave_reg;
for (byte = 0 ; byte < 4 ; byte++) {
addr_tmp = slave_reg_tmp & GENMASK(7 , 0 );
/*
* If an enable bit is not set in the
* MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG register , then the
* slave address slot associated with that bit is
* free . So set the enable bit and write the
* slave address bits .
*/
if (!(addr_tmp & MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT)) {
slave_reg &= ~(MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK << (byte * 8 ));
slave_reg |= (slave->addr << (byte * 8 ));
slave_reg |= MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT << (byte * 8 );
writel(slave_reg, priv->slv->io +
MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
(reg * 0 x4));
/*
* Set the slave at the corresponding index .
*/
priv->slave[(reg * 4 ) + byte] = slave;
return 0 ;
}
/* Parse next byte. */
slave_reg_tmp >>= 8 ;
}
}
return -EBUSY;
}
static int mlxbf_i2c_slave_disable(struct mlxbf_i2c_priv *priv, u8 addr)
{
u8 addr_tmp, reg, reg_cnt, byte;
u32 slave_reg, slave_reg_tmp;
reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2 ;
/*
* Read the slave registers . There are 4 * 32 - bit slave registers .
* Each slave register can hold up to 4 * 8 - bit slave configuration :
* 1 ) A 7 - bit address
* 2 ) And a status bit ( 1 if enabled , 0 if not ) .
* Check if addr is present in the registers .
*/
for (reg = 0 ; reg < reg_cnt; reg++) {
slave_reg = readl(priv->slv->io +
MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0 x4);
/* Check whether the address slots are empty. */
if (!slave_reg)
continue ;
/*
* Check if addr matches any of the 4 slave addresses
* in the register .
*/
slave_reg_tmp = slave_reg;
for (byte = 0 ; byte < 4 ; byte++) {
addr_tmp = slave_reg_tmp & MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK;
/*
* Parse slave address bytes and check whether the
* slave address already exists .
*/
if (addr_tmp == addr) {
/* Clear the slave address slot. */
slave_reg &= ~(GENMASK(7 , 0 ) << (byte * 8 ));
writel(slave_reg, priv->slv->io +
MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
(reg * 0 x4));
/* Free slave at the corresponding index */
priv->slave[(reg * 4 ) + byte] = NULL;
return 0 ;
}
/* Parse next byte. */
slave_reg_tmp >>= 8 ;
}
}
return -ENXIO;
}
static int mlxbf_i2c_init_coalesce(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
struct mlxbf_i2c_resource *coalesce_res;
struct resource *params;
resource_size_t size;
int ret = 0 ;
/*
* Unlike BlueField - 1 platform , the coalesce registers is a dedicated
* resource in the next generations of BlueField .
*/
if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) {
coalesce_res = mlxbf_i2c_get_shared_resource(priv,
MLXBF_I2C_COALESCE_RES);
if (!coalesce_res)
return -EPERM;
/*
* The Cause Coalesce group in TYU space is shared among
* I2C busses . This function MUST be serialized to avoid
* racing when claiming the memory region .
*/
lockdep_assert_held(mlxbf_i2c_gpio_res->lock);
/* Check whether the memory map exist. */
if (coalesce_res->io) {
priv->coalesce = coalesce_res;
return 0 ;
}
params = coalesce_res->params;
size = resource_size(params);
if (!request_mem_region(params->start, size, params->name))
return -EFAULT;
coalesce_res->io = ioremap(params->start, size);
if (!coalesce_res->io) {
release_mem_region(params->start, size);
return -ENOMEM;
}
priv->coalesce = coalesce_res;
} else {
ret = mlxbf_i2c_init_resource(pdev, &priv->coalesce,
MLXBF_I2C_COALESCE_RES);
}
return ret;
}
static int mlxbf_i2c_release_coalesce(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
struct mlxbf_i2c_resource *coalesce_res;
struct device *dev = &pdev->dev;
struct resource *params;
resource_size_t size;
coalesce_res = priv->coalesce;
if (coalesce_res->io) {
params = coalesce_res->params;
size = resource_size(params);
if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) {
mutex_lock(coalesce_res->lock);
iounmap(coalesce_res->io);
release_mem_region(params->start, size);
mutex_unlock(coalesce_res->lock);
} else {
devm_release_mem_region(dev, params->start, size);
}
}
return 0 ;
}
static int mlxbf_i2c_init_slave(struct platform_device *pdev,
struct mlxbf_i2c_priv *priv)
{
struct device *dev = &pdev->dev;
u32 int_reg;
int ret;
/* Reset FSM. */
writel(0 , priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_FSM);
/*
* Enable slave cause interrupt bits . Drive
* MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE and
* MLXBF_I2C_CAUSE_WRITE_SUCCESS , these are enabled when an external
* masters issue a Read and Write , respectively . But , clear all
* interrupts first .
*/
writel(~0 , priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
int_reg = MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE;
int_reg |= MLXBF_I2C_CAUSE_WRITE_SUCCESS;
writel(int_reg, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_EVTEN0);
/* Finally, set the 'ready' bit to start handling transactions. */
writel(0 x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
/* Initialize the cause coalesce resource. */
ret = mlxbf_i2c_init_coalesce(pdev, priv);
if (ret < 0 ) {
dev_err(dev, "failed to initialize cause coalesce\n" );
return ret;
}
return 0 ;
}
static bool mlxbf_i2c_has_coalesce(struct mlxbf_i2c_priv *priv, bool *read,
bool *write)
{
const struct mlxbf_i2c_chip_info *chip = priv->chip;
u32 coalesce0_reg, cause_reg;
u8 slave_shift, is_set;
*write = false ;
*read = false ;
slave_shift = chip->type != MLXBF_I2C_CHIP_TYPE_1 ?
MLXBF_I2C_CAUSE_YU_SLAVE_BIT :
priv->bus + MLXBF_I2C_CAUSE_TYU_SLAVE_BIT;
coalesce0_reg = readl(priv->coalesce->io + MLXBF_I2C_CAUSE_COALESCE_0);
is_set = coalesce0_reg & (1 << slave_shift);
if (!is_set)
return false ;
/* Check the source of the interrupt, i.e. whether a Read or Write. */
cause_reg = readl(priv->slv_cause->io + MLXBF_I2C_CAUSE_ARBITER);
if (cause_reg & MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE)
*read = true ;
else if (cause_reg & MLXBF_I2C_CAUSE_WRITE_SUCCESS)
*write = true ;
/* Clear cause bits. */
writel(~0 x0, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
return true ;
}
static struct i2c_client *mlxbf_i2c_get_slave_from_addr(
struct mlxbf_i2c_priv *priv, u8 addr)
{
int i;
for (i = 0 ; i < MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT; i++) {
if (!priv->slave[i])
continue ;
if (priv->slave[i]->addr == addr)
return priv->slave[i];
}
return NULL;
}
/*
* Send byte to ' external ' smbus master . This function is executed when
* an external smbus master wants to read data from the BlueField .
*/
static int mlxbf_i2c_irq_send(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
{
u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
u8 write_size, pec_en, addr, value, byte_cnt;
struct i2c_client *slave;
u32 control32, data32;
int ret = 0 ;
/*
* Read the first byte received from the external master to
* determine the slave address . This byte is located in the
* first data descriptor register of the slave GW .
*/
data32 = ioread32be(priv->slv->io +
MLXBF_I2C_SLAVE_DATA_DESC_ADDR);
addr = (data32 & GENMASK(7 , 0 )) >> 1 ;
/*
* Check if the slave address received in the data descriptor register
* matches any of the slave addresses registered . If there is a match ,
* set the slave .
*/
slave = mlxbf_i2c_get_slave_from_addr(priv, addr);
if (!slave) {
ret = -ENXIO;
goto clear_csr;
}
/*
* An I2C read can consist of a WRITE bit transaction followed by
* a READ bit transaction . Indeed , slave devices often expect
* the slave address to be followed by the internal address .
* So , write the internal address byte first , and then , send the
* requested data to the master .
*/
if (recv_bytes > 1 ) {
i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
value = (data32 >> 8 ) & GENMASK(7 , 0 );
ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
&value);
i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
if (ret < 0 )
goto clear_csr;
}
/*
* Send data to the master . Currently , the driver supports
* READ_BYTE , READ_WORD and BLOCK READ protocols . The
* hardware can send up to 128 bytes per transfer which is
* the total size of the data registers .
*/
i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
for (byte_cnt = 0 ; byte_cnt < MLXBF_I2C_SLAVE_DATA_DESC_SIZE; byte_cnt++) {
data_desc[byte_cnt] = value;
i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value);
}
/* Send a stop condition to the backend. */
i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
/* Set the number of bytes to write to master. */
write_size = (byte_cnt - 1 ) & 0 x7f;
/* Write data to Slave GW data descriptor. */
mlxbf_i2c_smbus_write_data(priv, data_desc, byte_cnt,
MLXBF_I2C_SLAVE_DATA_DESC_ADDR, false );
pec_en = 0 ; /* Disable PEC since it is not supported. */
/* Prepare control word. */
control32 = MLXBF_I2C_SLAVE_ENABLE;
control32 |= rol32(write_size, MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT);
control32 |= rol32(pec_en, MLXBF_I2C_SLAVE_SEND_PEC_SHIFT);
writel(control32, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_GW);
/*
* Wait until the transfer is completed ; the driver will wait
* until the GW is idle , a cause will rise on fall of GW busy .
*/
readl_poll_timeout_atomic(priv->slv_cause->io + MLXBF_I2C_CAUSE_ARBITER,
data32, data32 & MLXBF_I2C_CAUSE_S_GW_BUSY_FALL,
MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT);
clear_csr:
/* Release the Slave GW. */
writel(0 x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
writel(0 x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
writel(0 x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
return ret;
}
/*
* Receive bytes from ' external ' smbus master . This function is executed when
* an external smbus master wants to write data to the BlueField .
*/
static int mlxbf_i2c_irq_recv(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
{
u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
struct i2c_client *slave;
u8 value, byte, addr;
int ret = 0 ;
/* Read data from Slave GW data descriptor. */
mlxbf_i2c_smbus_read_data(priv, data_desc, recv_bytes,
MLXBF_I2C_SLAVE_DATA_DESC_ADDR, false );
addr = data_desc[0 ] >> 1 ;
/*
* Check if the slave address received in the data descriptor register
* matches any of the slave addresses registered .
*/
slave = mlxbf_i2c_get_slave_from_addr(priv, addr);
if (!slave) {
ret = -EINVAL;
goto clear_csr;
}
/*
* Notify the slave backend that an smbus master wants to write data
* to the BlueField .
*/
i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
/* Send the received data to the slave backend. */
for (byte = 1 ; byte < recv_bytes; byte++) {
value = data_desc[byte];
ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
&value);
if (ret < 0 )
break ;
}
/*
* Send a stop event to the slave backend , to signal
* the end of the write transactions .
*/
i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
clear_csr:
/* Release the Slave GW. */
writel(0 x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
writel(0 x0, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
writel(0 x1, priv->slv->io + MLXBF_I2C_SMBUS_SLAVE_READY);
return ret;
}
static irqreturn_t mlxbf_i2c_irq(int irq, void *ptr)
{
struct mlxbf_i2c_priv *priv = ptr;
bool read, write, irq_is_set;
u32 rw_bytes_reg;
u8 recv_bytes;
/*
* Read TYU interrupt register and determine the source of the
* interrupt . Based on the source of the interrupt one of the
* following actions are performed :
* - Receive data and send response to master .
* - Send data and release slave GW .
*
* Handle read / write transaction only . CRmaster and Iarp requests
* are ignored for now .
*/
irq_is_set = mlxbf_i2c_has_coalesce(priv, &read, &write);
if (!irq_is_set || (!read && !write)) {
/* Nothing to do here, interrupt was not from this device. */
return IRQ_NONE;
}
/*
* The MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES includes the number of
* bytes from / to master . These are defined by 8 - bits each . If the lower
* 8 bits are set , then the master expect to read N bytes from the
* slave , if the higher 8 bits are sent then the slave expect N bytes
* from the master .
*/
rw_bytes_reg = readl(priv->slv->io +
MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
recv_bytes = (rw_bytes_reg >> 8 ) & GENMASK(7 , 0 );
/*
* For now , the slave supports 128 bytes transfer . Discard remaining
* data bytes if the master wrote more than
* MLXBF_I2C_SLAVE_DATA_DESC_SIZE , i . e , the actual size of the slave
* data descriptor .
*
* Note that we will never expect to transfer more than 128 bytes ; as
* specified in the SMBus standard , block transactions cannot exceed
* 32 bytes .
*/
recv_bytes = recv_bytes > MLXBF_I2C_SLAVE_DATA_DESC_SIZE ?
MLXBF_I2C_SLAVE_DATA_DESC_SIZE : recv_bytes;
if (read)
mlxbf_i2c_irq_send(priv, recv_bytes);
else
mlxbf_i2c_irq_recv(priv, recv_bytes);
return IRQ_HANDLED;
}
/* Return negative errno on error. */
static s32 mlxbf_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size,
union i2c_smbus_data *data)
{
struct mlxbf_i2c_smbus_request request = { 0 };
struct mlxbf_i2c_priv *priv;
bool read, pec;
u8 byte_cnt;
request.slave = addr;
read = (read_write == I2C_SMBUS_READ);
pec = flags & I2C_FUNC_SMBUS_PEC;
switch (size) {
case I2C_SMBUS_QUICK:
mlxbf_i2c_smbus_quick_command(&request, read);
dev_dbg(&adap->dev, "smbus quick, slave 0x%02x\n" , addr);
break ;
case I2C_SMBUS_BYTE:
mlxbf_i2c_smbus_byte_func(&request,
read ? &data->byte : &command, read,
pec);
dev_dbg(&adap->dev, "smbus %s byte, slave 0x%02x.\n" ,
str_read_write(read), addr);
break ;
case I2C_SMBUS_BYTE_DATA:
mlxbf_i2c_smbus_data_byte_func(&request, &command, &data->byte,
read, pec);
dev_dbg(&adap->dev, "smbus %s byte data at 0x%02x, slave 0x%02x.\n" ,
str_read_write(read), command, addr);
break ;
case I2C_SMBUS_WORD_DATA:
mlxbf_i2c_smbus_data_word_func(&request, &command,
(u8 *)&data->word, read, pec);
dev_dbg(&adap->dev, "smbus %s word data at 0x%02x, slave 0x%02x.\n" ,
str_read_write(read), command, addr);
break ;
case I2C_SMBUS_I2C_BLOCK_DATA:
byte_cnt = data->block[0 ];
mlxbf_i2c_smbus_i2c_block_func(&request, &command, data->block,
&byte_cnt, read, pec);
dev_dbg(&adap->dev, "i2c %s block data, %d bytes at 0x%02x, slave 0x%02x.\n" ,
str_read_write(read), byte_cnt, command, addr);
break ;
case I2C_SMBUS_BLOCK_DATA:
byte_cnt = read ? I2C_SMBUS_BLOCK_MAX : data->block[0 ];
mlxbf_i2c_smbus_block_func(&request, &command, data->block,
&byte_cnt, read, pec);
dev_dbg(&adap->dev, "smbus %s block data, %d bytes at 0x%02x, slave 0x%02x.\n" ,
str_read_write(read), byte_cnt, command, addr);
break ;
case I2C_FUNC_SMBUS_PROC_CALL:
mlxbf_i2c_smbus_process_call_func(&request, &command,
(u8 *)&data->word, pec);
dev_dbg(&adap->dev, "process call, wr/rd at 0x%02x, slave 0x%02x.\n" ,
command, addr);
break ;
case I2C_FUNC_SMBUS_BLOCK_PROC_CALL:
byte_cnt = data->block[0 ];
mlxbf_i2c_smbus_blk_process_call_func(&request, &command,
data->block, &byte_cnt,
pec);
dev_dbg(&adap->dev, "block process call, wr/rd %d bytes, slave 0x%02x.\n" ,
byte_cnt, addr);
break ;
default :
dev_dbg(&adap->dev, "Unsupported I2C/SMBus command %d\n" ,
size);
return -EOPNOTSUPP;
}
priv = i2c_get_adapdata(adap);
return mlxbf_i2c_smbus_start_transaction(priv, &request);
}
static int mlxbf_i2c_reg_slave(struct i2c_client *slave)
{
struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
struct device *dev = &slave->dev;
int ret;
/*
* Do not support ten bit chip address and do not use Packet Error
* Checking ( PEC ) .
*/
if (slave->flags & (I2C_CLIENT_TEN | I2C_CLIENT_PEC)) {
dev_err(dev, "SMBus PEC and 10 bit address not supported\n" );
return -EAFNOSUPPORT;
}
ret = mlxbf_i2c_slave_enable(priv, slave);
if (ret)
dev_err(dev, "Surpassed max number of registered slaves allowed\n" );
return 0 ;
}
static int mlxbf_i2c_unreg_slave(struct i2c_client *slave)
{
struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
struct device *dev = &slave->dev;
int ret;
/*
* Unregister slave by :
* 1 ) Disabling the slave address in hardware
* 2 ) Freeing priv - > slave at the corresponding index
*/
ret = mlxbf_i2c_slave_disable(priv, slave->addr);
if (ret)
dev_err(dev, "Unable to find slave 0x%x\n" , slave->addr);
return ret;
}
static u32 mlxbf_i2c_functionality(struct i2c_adapter *adap)
{
return MLXBF_I2C_FUNC_ALL;
}
static struct mlxbf_i2c_chip_info mlxbf_i2c_chip[] = {
[MLXBF_I2C_CHIP_TYPE_1] = {
.type = MLXBF_I2C_CHIP_TYPE_1,
.shared_res = {
[0 ] = &mlxbf_i2c_coalesce_res[MLXBF_I2C_CHIP_TYPE_1],
[1 ] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_1],
[2 ] = &mlxbf_i2c_gpio_res[MLXBF_I2C_CHIP_TYPE_1]
},
.calculate_freq = mlxbf_i2c_calculate_freq_from_tyu,
.smbus_master_rs_bytes_off = MLXBF_I2C_YU_SMBUS_RS_BYTES,
.smbus_master_fsm_off = MLXBF_I2C_YU_SMBUS_MASTER_FSM
},
[MLXBF_I2C_CHIP_TYPE_2] = {
.type = MLXBF_I2C_CHIP_TYPE_2,
.shared_res = {
[0 ] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_2]
},
.calculate_freq = mlxbf_i2c_calculate_freq_from_yu,
.smbus_master_rs_bytes_off = MLXBF_I2C_YU_SMBUS_RS_BYTES,
.smbus_master_fsm_off = MLXBF_I2C_YU_SMBUS_MASTER_FSM
},
[MLXBF_I2C_CHIP_TYPE_3] = {
.type = MLXBF_I2C_CHIP_TYPE_3,
.shared_res = {
[0 ] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_3]
},
.calculate_freq = mlxbf_i2c_calculate_freq_from_yu,
.smbus_master_rs_bytes_off = MLXBF_I2C_RSH_YU_SMBUS_RS_BYTES,
.smbus_master_fsm_off = MLXBF_I2C_RSH_YU_SMBUS_MASTER_FSM
}
};
static const struct i2c_algorithm mlxbf_i2c_algo = {
.smbus_xfer = mlxbf_i2c_smbus_xfer,
.functionality = mlxbf_i2c_functionality,
.reg_slave = mlxbf_i2c_reg_slave,
.unreg_slave = mlxbf_i2c_unreg_slave,
};
static struct i2c_adapter_quirks mlxbf_i2c_quirks = {
.max_read_len = MLXBF_I2C_MASTER_DATA_R_LENGTH,
.max_write_len = MLXBF_I2C_MASTER_DATA_W_LENGTH,
};
static const struct acpi_device_id mlxbf_i2c_acpi_ids[] = {
{ "MLNXBF03" , (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_1] },
{ "MLNXBF23" , (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_2] },
{ "MLNXBF31" , (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_3] },
{},
};
MODULE_DEVICE_TABLE(acpi, mlxbf_i2c_acpi_ids);
static int mlxbf_i2c_acpi_probe(struct device *dev, struct mlxbf_i2c_priv *priv)
{
const struct acpi_device_id *aid;
u64 bus_id;
int ret;
if (acpi_disabled)
return -ENOENT;
aid = acpi_match_device(mlxbf_i2c_acpi_ids, dev);
if (!aid)
return -ENODEV;
priv->chip = (struct mlxbf_i2c_chip_info *)aid->driver_data;
ret = acpi_dev_uid_to_integer(ACPI_COMPANION(dev), &bus_id);
if (ret) {
dev_err(dev, "Cannot retrieve UID\n" );
return ret;
}
priv->bus = bus_id;
return 0 ;
}
static int mlxbf_i2c_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct mlxbf_i2c_priv *priv;
struct i2c_adapter *adap;
u32 resource_version;
int irq, ret;
priv = devm_kzalloc(dev, sizeof (struct mlxbf_i2c_priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
ret = mlxbf_i2c_acpi_probe(dev, priv);
if (ret < 0 )
return ret;
/* This property allows the driver to stay backward compatible with older
* ACPI tables .
* Starting BlueField - 3 SoC , the " smbus " resource was broken down into 3
* separate resources " timer " , " master " and " slave " .
*/
if (device_property_read_u32(dev, "resource_version" , &resource_version))
resource_version = 0 ;
priv->resource_version = resource_version;
if (priv->chip->type < MLXBF_I2C_CHIP_TYPE_3 && resource_version == 0 ) {
priv->timer = devm_kzalloc(dev, sizeof (struct mlxbf_i2c_resource), GFP_KERNEL);
if (!priv->timer)
return -ENOMEM;
priv->mst = devm_kzalloc(dev, sizeof (struct mlxbf_i2c_resource), GFP_KERNEL);
if (!priv->mst)
return -ENOMEM;
priv->slv = devm_kzalloc(dev, sizeof (struct mlxbf_i2c_resource), GFP_KERNEL);
if (!priv->slv)
return -ENOMEM;
ret = mlxbf_i2c_init_resource(pdev, &priv->smbus,
MLXBF_I2C_SMBUS_RES);
if (ret < 0 )
return dev_err_probe(dev, ret, "Cannot fetch smbus resource info" );
priv->timer->io = priv->smbus->io;
priv->mst->io = priv->smbus->io + MLXBF_I2C_MST_ADDR_OFFSET;
priv->slv->io = priv->smbus->io + MLXBF_I2C_SLV_ADDR_OFFSET;
} else {
ret = mlxbf_i2c_init_resource(pdev, &priv->timer,
MLXBF_I2C_SMBUS_TIMER_RES);
if (ret < 0 )
return dev_err_probe(dev, ret, "Cannot fetch timer resource info" );
ret = mlxbf_i2c_init_resource(pdev, &priv->mst,
MLXBF_I2C_SMBUS_MST_RES);
if (ret < 0 )
return dev_err_probe(dev, ret, "Cannot fetch master resource info" );
ret = mlxbf_i2c_init_resource(pdev, &priv->slv,
MLXBF_I2C_SMBUS_SLV_RES);
if (ret < 0 )
return dev_err_probe(dev, ret, "Cannot fetch slave resource info" );
}
ret = mlxbf_i2c_init_resource(pdev, &priv->mst_cause,
MLXBF_I2C_MST_CAUSE_RES);
if (ret < 0 )
return dev_err_probe(dev, ret, "Cannot fetch cause master resource info" );
ret = mlxbf_i2c_init_resource(pdev, &priv->slv_cause,
MLXBF_I2C_SLV_CAUSE_RES);
if (ret < 0 )
return dev_err_probe(dev, ret, "Cannot fetch cause slave resource info" );
adap = &priv->adap;
adap->owner = THIS_MODULE;
adap->class = I2C_CLASS_HWMON;
adap->algo = &mlxbf_i2c_algo;
adap->quirks = &mlxbf_i2c_quirks;
adap->dev.parent = dev;
adap->dev.of_node = dev->of_node;
adap->nr = priv->bus;
snprintf(adap->name, sizeof (adap->name), "i2c%d" , adap->nr);
i2c_set_adapdata(adap, priv);
/* Read Core PLL frequency. */
ret = mlxbf_i2c_calculate_corepll_freq(pdev, priv);
if (ret < 0 ) {
dev_err(dev, "cannot get core clock frequency\n" );
/* Set to default value. */
priv->frequency = MLXBF_I2C_COREPLL_FREQ;
}
/*
* Initialize master .
* Note that a physical bus might be shared among Linux and firmware
* ( e . g . , ATF ) . Thus , the bus should be initialized and ready and
* bus initialization would be unnecessary . This requires additional
* knowledge about physical busses . But , since an extra initialization
* does not really hurt , then keep the code as is .
*/
ret = mlxbf_i2c_init_master(pdev, priv);
if (ret < 0 )
return dev_err_probe(dev, ret, "failed to initialize smbus master %d" ,
priv->bus);
mlxbf_i2c_init_timings(pdev, priv);
mlxbf_i2c_init_slave(pdev, priv);
irq = platform_get_irq(pdev, 0 );
if (irq < 0 )
return irq;
ret = devm_request_irq(dev, irq, mlxbf_i2c_irq,
IRQF_SHARED | IRQF_PROBE_SHARED,
dev_name(dev), priv);
if (ret < 0 )
return dev_err_probe(dev, ret, "Cannot get irq %d\n" , irq);
priv->irq = irq;
platform_set_drvdata(pdev, priv);
ret = i2c_add_numbered_adapter(adap);
if (ret < 0 )
return ret;
mutex_lock(&mlxbf_i2c_bus_lock);
mlxbf_i2c_bus_count++;
mutex_unlock(&mlxbf_i2c_bus_lock);
return 0 ;
}
static void mlxbf_i2c_remove(struct platform_device *pdev)
{
struct mlxbf_i2c_priv *priv = platform_get_drvdata(pdev);
struct device *dev = &pdev->dev;
struct resource *params;
if (priv->chip->type < MLXBF_I2C_CHIP_TYPE_3 && priv->resource_version == 0 ) {
params = priv->smbus->params;
devm_release_mem_region(dev, params->start, resource_size(params));
} else {
params = priv->timer->params;
devm_release_mem_region(dev, params->start, resource_size(params));
params = priv->mst->params;
devm_release_mem_region(dev, params->start, resource_size(params));
params = priv->slv->params;
devm_release_mem_region(dev, params->start, resource_size(params));
}
params = priv->mst_cause->params;
devm_release_mem_region(dev, params->start, resource_size(params));
params = priv->slv_cause->params;
devm_release_mem_region(dev, params->start, resource_size(params));
/*
* Release shared resources . This should be done when releasing
* the I2C controller .
*/
mutex_lock(&mlxbf_i2c_bus_lock);
if (--mlxbf_i2c_bus_count == 0 ) {
mlxbf_i2c_release_coalesce(pdev, priv);
mlxbf_i2c_release_corepll(pdev, priv);
mlxbf_i2c_release_gpio(pdev, priv);
}
mutex_unlock(&mlxbf_i2c_bus_lock);
devm_free_irq(dev, priv->irq, priv);
i2c_del_adapter(&priv->adap);
}
static struct platform_driver mlxbf_i2c_driver = {
.probe = mlxbf_i2c_probe,
.remove = mlxbf_i2c_remove,
.driver = {
.name = "i2c-mlxbf" ,
.acpi_match_table = ACPI_PTR(mlxbf_i2c_acpi_ids),
},
};
static int __init mlxbf_i2c_init(void )
{
mutex_init(&mlxbf_i2c_coalesce_lock);
mutex_init(&mlxbf_i2c_corepll_lock);
mutex_init(&mlxbf_i2c_gpio_lock);
mutex_init(&mlxbf_i2c_bus_lock);
return platform_driver_register(&mlxbf_i2c_driver);
}
module_init(mlxbf_i2c_init);
static void __exit mlxbf_i2c_exit(void )
{
platform_driver_unregister(&mlxbf_i2c_driver);
mutex_destroy(&mlxbf_i2c_bus_lock);
mutex_destroy(&mlxbf_i2c_gpio_lock);
mutex_destroy(&mlxbf_i2c_corepll_lock);
mutex_destroy(&mlxbf_i2c_coalesce_lock);
}
module_exit(mlxbf_i2c_exit);
MODULE_DESCRIPTION("Mellanox BlueField I2C bus driver" );
MODULE_AUTHOR("Khalil Blaiech <kblaiech@nvidia.com>" );
MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>" );
MODULE_LICENSE("GPL v2" );
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