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linux/drivers/i2c/busses/i2c-mlxbf.c
Khalil Blaiech 54b9c3d0ce i2c: mlxbf: Update author and maintainer email info 
Correct the email addresses of the author and the maintainer
of the Mellanox BlueField I2C driver.

Fixes: b5b5b32081 ("i2c: mlxbf: I2C SMBus driver for Mellanox BlueField SoC")
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Khalil Blaiech <kblaiech@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-11-06 15:52:19 +01:00

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// 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 - 156 MHz. */
#define MLXBF_I2C_PLL_IN_FREQ (156 * 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
/*
* 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 = readl(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 = 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->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.
* 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));
iowrite32be(data32, priv->smbus->io + addr + offset);
}
}
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;
/*
* 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)) {
data32 = ioread32be(priv->smbus->io + addr + offset);
*((u32 *)(data + offset)) = data32;
}
if (!(length & mask))
return;
data32 = ioread32be(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. */
writel(0x0, priv->smbus->io + MLXBF_I2C_SMBUS_MASTER_STATUS);
/* Set the cause data. */
writel(~0x0, priv->smbus->io + MLXBF_I2C_CAUSE_OR_CLEAR);
/* Zero PEC byte. */
writel(0x0, priv->smbus->io + MLXBF_I2C_SMBUS_MASTER_PEC);
/* Zero byte count. */
writel(0x0, priv->smbus->io + MLXBF_I2C_SMBUS_RS_BYTES);
/* GW activation. */
writel(command, priv->smbus->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;
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.
*/
writel(MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK,
priv->smbus->io + MLXBF_I2C_SMBUS_MASTER_FSM);
}
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,
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->params = platform_get_resource(pdev, IORESOURCE_MEM, type);
if (!tmp_res->params) {
devm_kfree(dev, tmp_res);
return -EIO;
}
tmp_res->io = devm_ioremap_resource(dev, 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 = (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->smbus->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->smbus->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->smbus->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->smbus->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->smbus->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->smbus->io + MLXBF_I2C_SMBUS_THIGH_MAX_TBUF);
timer = timings->timeout;
writel(timer, priv->smbus->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,
};
/*
* Note that the mlxbf_i2c_timings->timeout value is not related to the
* bus frequency, it is impacted by the time it takes the driver to
* complete data transmission before transaction abort.
*/
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 = 5000,
.timeout = 106500
},
[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 = 5000,
.timeout = 106500
},
[MLXBF_I2C_TIMING_CONFIG_1000KHZ] = {
.scl_high = 600,
.scl_low = 1300,
.hold_start = 600,
.setup_start = 600,
.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 = 5000,
.timeout = 106500
}
};
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 = MLXBF_I2C_TIMING_100KHZ;
switch (config_khz) {
default:
/* Default settings is 100 KHz. */
pr_warn("Illegal value %d: defaulting to 100 KHz\n",
config_khz);
fallthrough;
case MLXBF_I2C_TIMING_100KHZ:
config_idx = MLXBF_I2C_TIMING_CONFIG_100KHZ;
break;
case MLXBF_I2C_TIMING_400KHZ:
config_idx = MLXBF_I2C_TIMING_CONFIG_400KHZ;
break;
case MLXBF_I2C_TIMING_1000KHZ:
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 (IS_ERR(gpio_res->io)) {
devm_release_mem_region(dev, params->start, size);
return PTR_ERR(gpio_res->io);
}
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 (IS_ERR(corepll_res->io)) {
devm_release_mem_region(dev, params->start, size);
return PTR_ERR(corepll_res->io);
}
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_calculate_freq_from_tyu(struct mlxbf_i2c_resource *corepll_res)
{
u64 core_frequency, pad_frequency;
u8 core_od, core_r;
u32 corepll_val;
u16 core_f;
pad_frequency = MLXBF_I2C_PLL_IN_FREQ;
corepll_val = readl(corepll_res->io + MLXBF_I2C_CORE_PLL_REG1);
/* Get Core PLL configuration bits. */
core_f = rol32(corepll_val, MLXBF_I2C_COREPLL_CORE_F_TYU_SHIFT) &
MLXBF_I2C_COREPLL_CORE_F_TYU_MASK;
core_od = rol32(corepll_val, MLXBF_I2C_COREPLL_CORE_OD_TYU_SHIFT) &
MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK;
core_r = rol32(corepll_val, MLXBF_I2C_COREPLL_CORE_R_TYU_SHIFT) &
MLXBF_I2C_COREPLL_CORE_R_TYU_MASK;
/*
* 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 = pad_frequency * (++core_f);
core_frequency /= (++core_r) * (++core_od);
return core_frequency;
}
static u64 mlxbf_calculate_freq_from_yu(struct mlxbf_i2c_resource *corepll_res)
{
u32 corepll_reg1_val, corepll_reg2_val;
u64 corepll_frequency, pad_frequency;
u8 core_od, core_r;
u32 core_f;
pad_frequency = MLXBF_I2C_PLL_IN_FREQ;
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 = rol32(corepll_reg1_val, MLXBF_I2C_COREPLL_CORE_F_YU_SHIFT) &
MLXBF_I2C_COREPLL_CORE_F_YU_MASK;
core_r = rol32(corepll_reg1_val, MLXBF_I2C_COREPLL_CORE_R_YU_SHIFT) &
MLXBF_I2C_COREPLL_CORE_R_YU_MASK;
core_od = rol32(corepll_reg2_val, MLXBF_I2C_COREPLL_CORE_OD_YU_SHIFT) &
MLXBF_I2C_COREPLL_CORE_OD_YU_MASK;
/*
* 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 = (pad_frequency * core_f) / MLNXBF_I2C_COREPLL_CONST;
corepll_frequency /= (++core_r) * (++core_od);
return corepll_frequency;
}
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_slave_enable(struct mlxbf_i2c_priv *priv, u8 addr)
{
u32 slave_reg, slave_reg_tmp, slave_reg_avail, slave_addr_mask;
u8 reg, reg_cnt, byte, addr_tmp, reg_avail, byte_avail;
bool avail, disabled;
disabled = false;
avail = false;
if (!priv)
return -EPERM;
reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2;
slave_addr_mask = MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK;
/*
* Read the slave registers. There are 4 * 32-bit slave registers.
* Each slave register can hold up to 4 * 8-bit slave configuration
* (7-bit address, 1 status bit (1 if enabled, 0 if not)).
*/
for (reg = 0; reg < reg_cnt; reg++) {
slave_reg = readl(priv->smbus->io +
MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4);
/*
* 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);
/*
* Mark the first available slave address slot, i.e. its
* enabled bit should be unset. This slot might be used
* later on to register our slave.
*/
if (!avail && !MLXBF_I2C_SLAVE_ADDR_ENABLED(addr_tmp)) {
avail = true;
reg_avail = reg;
byte_avail = byte;
slave_reg_avail = slave_reg;
}
/*
* Parse slave address bytes and check whether the
* slave address already exists and it's enabled,
* i.e. most significant bit is set.
*/
if ((addr_tmp & slave_addr_mask) == addr) {
if (MLXBF_I2C_SLAVE_ADDR_ENABLED(addr_tmp))
return 0;
disabled = true;
break;
}
/* Parse next byte. */
slave_reg_tmp >>= 8;
}
/* Exit the loop if the slave address is found. */
if (disabled)
break;
}
if (!avail && !disabled)
return -EINVAL; /* No room for a new slave address. */
if (avail && !disabled) {
reg = reg_avail;
byte = byte_avail;
/* Set the slave address. */
slave_reg_avail &= ~(slave_addr_mask << (byte * 8));
slave_reg_avail |= addr << (byte * 8);
slave_reg = slave_reg_avail;
}
/* Enable the slave address and update the register. */
slave_reg |= (1 << MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT) << (byte * 8);
writel(slave_reg, priv->smbus->io + MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
reg * 0x4);
return 0;
}
static int mlxbf_slave_disable(struct mlxbf_i2c_priv *priv)
{
u32 slave_reg, slave_reg_tmp, slave_addr_mask;
u8 addr, addr_tmp, reg, reg_cnt, slave_byte;
struct i2c_client *client = priv->slave;
bool exist;
exist = false;
addr = client->addr;
reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2;
slave_addr_mask = MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK;
/*
* Read the slave registers. There are 4 * 32-bit slave registers.
* Each slave register can hold up to 4 * 8-bit slave configuration
* (7-bit address, 1 status bit (1 if enabled, 0 if not)).
*/
for (reg = 0; reg < reg_cnt; reg++) {
slave_reg = readl(priv->smbus->io +
MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4);
/* Check whether the address slots are empty. */
if (slave_reg == 0)
continue;
/*
* 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;
slave_byte = 0;
while (slave_reg_tmp != 0) {
addr_tmp = slave_reg_tmp & slave_addr_mask;
/*
* Parse slave address bytes and check whether the
* slave address already exists.
*/
if (addr_tmp == addr) {
exist = true;
break;
}
/* Parse next byte. */
slave_reg_tmp >>= 8;
slave_byte += 1;
}
/* Exit the loop if the slave address is found. */
if (exist)
break;
}
if (!exist)
return 0; /* Slave is not registered, nothing to do. */
/* Cleanup the slave address slot. */
slave_reg &= ~(GENMASK(7, 0) << (slave_byte * 8));
writel(slave_reg, priv->smbus->io + MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG +
reg * 0x4);
return 0;
}
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 (IS_ERR(coalesce_res->io)) {
release_mem_region(params->start, size);
return PTR_ERR(coalesce_res->io);
}
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->smbus->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(0x1, priv->smbus->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(~0x0, priv->slv_cause->io + MLXBF_I2C_CAUSE_OR_CLEAR);
return true;
}
static bool mlxbf_smbus_slave_wait_for_idle(struct mlxbf_i2c_priv *priv,
u32 timeout)
{
u32 mask = MLXBF_I2C_CAUSE_S_GW_BUSY_FALL;
u32 addr = MLXBF_I2C_CAUSE_ARBITER;
if (mlxbf_smbus_poll(priv->slv_cause->io, addr, mask, false, timeout))
return true;
return false;
}
/* Send byte to 'external' smbus master. */
static int mlxbf_smbus_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, byte, value, byte_cnt, desc_size;
struct i2c_client *slave = priv->slave;
u32 control32, data32;
int ret;
if (!slave)
return -EINVAL;
addr = 0;
byte = 0;
desc_size = MLXBF_I2C_SLAVE_DATA_DESC_SIZE;
/*
* Read bytes received from the external master. These bytes should
* be located in the first data descriptor register of the slave GW.
* These bytes are the slave address byte and the internal register
* address, if supplied.
*/
if (recv_bytes > 0) {
data32 = ioread32be(priv->smbus->io +
MLXBF_I2C_SLAVE_DATA_DESC_ADDR);
/* Parse the received bytes. */
switch (recv_bytes) {
case 2:
byte = (data32 >> 8) & GENMASK(7, 0);
fallthrough;
case 1:
addr = (data32 & GENMASK(7, 0)) >> 1;
}
/* Check whether it's our slave address. */
if (slave->addr != addr)
return -EINVAL;
}
/*
* I2C read transactions may start by a WRITE followed by a READ.
* Indeed, most slave devices would expect the internal address
* following the slave address byte. So, write that byte first,
* and then, send the requested data bytes to the master.
*/
if (recv_bytes > 1) {
i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
value = byte;
ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED,
&value);
i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
if (ret < 0)
return ret;
}
/*
* Now, send data to the master; currently, the driver supports
* READ_BYTE, READ_WORD and BLOCK READ protocols. Note that the
* hardware can send up to 128 bytes per transfer. That is the
* size of its data registers.
*/
i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
for (byte_cnt = 0; byte_cnt < 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);
/* Handle the actual transfer. */
/* Set the number of bytes to write to master. */
write_size = (byte_cnt - 1) & 0x7f;
/* Write data to Slave GW data descriptor. */
mlxbf_i2c_smbus_write_data(priv, data_desc, byte_cnt,
MLXBF_I2C_SLAVE_DATA_DESC_ADDR);
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->smbus->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.
*/
mlxbf_smbus_slave_wait_for_idle(priv, MLXBF_I2C_SMBUS_TIMEOUT);
/* Release the Slave GW. */
writel(0x0, priv->smbus->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
writel(0x0, priv->smbus->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
writel(0x1, priv->smbus->io + MLXBF_I2C_SMBUS_SLAVE_READY);
return 0;
}
/* Receive bytes from 'external' smbus master. */
static int mlxbf_smbus_irq_recv(struct mlxbf_i2c_priv *priv, u8 recv_bytes)
{
u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 };
struct i2c_client *slave = priv->slave;
u8 value, byte, addr;
int ret = 0;
if (!slave)
return -EINVAL;
/* Read data from Slave GW data descriptor. */
mlxbf_i2c_smbus_read_data(priv, data_desc, recv_bytes,
MLXBF_I2C_SLAVE_DATA_DESC_ADDR);
/* Check whether its our slave address. */
addr = data_desc[0] >> 1;
if (slave->addr != addr)
return -EINVAL;
/*
* Notify the slave backend; another I2C master wants to write data
* to us. This event is sent once the slave address and the write bit
* is detected.
*/
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 condition to the backend. */
i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
/* Release the Slave GW. */
writel(0x0, priv->smbus->io + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES);
writel(0x0, priv->smbus->io + MLXBF_I2C_SMBUS_SLAVE_PEC);
writel(0x1, priv->smbus->io + MLXBF_I2C_SMBUS_SLAVE_READY);
return ret;
}
static irqreturn_t mlxbf_smbus_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->smbus->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_smbus_irq_send(priv, recv_bytes);
else
mlxbf_smbus_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",
read ? "read" : "write", 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",
read ? "read" : "write", 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",
read ? "read" : "write", 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",
read ? "read" : "write", 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",
read ? "read" : "write", 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);
int ret;
if (priv->slave)
return -EBUSY;
/*
* Do not support ten bit chip address and do not use Packet Error
* Checking (PEC).
*/
if (slave->flags & (I2C_CLIENT_TEN | I2C_CLIENT_PEC))
return -EAFNOSUPPORT;
ret = mlxbf_slave_enable(priv, slave->addr);
if (ret < 0)
return ret;
priv->slave = slave;
return 0;
}
static int mlxbf_i2c_unreg_slave(struct i2c_client *slave)
{
struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
int ret;
WARN_ON(!priv->slave);
/* Unregister slave, i.e. disable the slave address in hardware. */
ret = mlxbf_slave_disable(priv);
if (ret < 0)
return ret;
priv->slave = NULL;
return 0;
}
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_calculate_freq_from_tyu
},
[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_calculate_freq_from_yu
}
};
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 of_device_id mlxbf_i2c_dt_ids[] = {
{
.compatible = "mellanox,i2c-mlxbf1",
.data = &mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_1]
},
{
.compatible = "mellanox,i2c-mlxbf2",
.data = &mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_2]
},
{},
};
MODULE_DEVICE_TABLE(of, mlxbf_i2c_dt_ids);
#ifdef CONFIG_ACPI
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] },
{},
};
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;
struct acpi_device *adev;
unsigned long bus_id = 0;
const char *uid;
int ret;
if (acpi_disabled)
return -ENOENT;
adev = ACPI_COMPANION(dev);
if (!adev)
return -ENXIO;
aid = acpi_match_device(mlxbf_i2c_acpi_ids, dev);
if (!aid)
return -ENODEV;
priv->chip = (struct mlxbf_i2c_chip_info *)aid->driver_data;
uid = acpi_device_uid(adev);
if (!uid || !(*uid)) {
dev_err(dev, "Cannot retrieve UID\n");
return -ENODEV;
}
ret = kstrtoul(uid, 0, &bus_id);
if (!ret)
priv->bus = bus_id;
return ret;
}
#else
static int mlxbf_i2c_acpi_probe(struct device *dev, struct mlxbf_i2c_priv *priv)
{
return -ENOENT;
}
#endif /* CONFIG_ACPI */
static int mlxbf_i2c_of_probe(struct device *dev, struct mlxbf_i2c_priv *priv)
{
const struct of_device_id *oid;
int bus_id = -1;
if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
oid = of_match_node(mlxbf_i2c_dt_ids, dev->of_node);
if (!oid)
return -ENODEV;
priv->chip = oid->data;
bus_id = of_alias_get_id(dev->of_node, "i2c");
if (bus_id >= 0)
priv->bus = bus_id;
}
if (bus_id < 0) {
dev_err(dev, "Cannot get bus id");
return 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;
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 && ret != -ENOENT && ret != -ENXIO)
ret = mlxbf_i2c_of_probe(dev, priv);
if (ret < 0)
return ret;
ret = mlxbf_i2c_init_resource(pdev, &priv->smbus,
MLXBF_I2C_SMBUS_RES);
if (ret < 0) {
dev_err(dev, "Cannot fetch smbus resource info");
return ret;
}
ret = mlxbf_i2c_init_resource(pdev, &priv->mst_cause,
MLXBF_I2C_MST_CAUSE_RES);
if (ret < 0) {
dev_err(dev, "Cannot fetch cause master resource info");
return ret;
}
ret = mlxbf_i2c_init_resource(pdev, &priv->slv_cause,
MLXBF_I2C_SLV_CAUSE_RES);
if (ret < 0) {
dev_err(dev, "Cannot fetch cause slave resource info");
return ret;
}
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) {
dev_err(dev, "failed to initialize smbus master %d",
priv->bus);
return ret;
}
mlxbf_i2c_init_timings(pdev, priv);
mlxbf_i2c_init_slave(pdev, priv);
irq = platform_get_irq(pdev, 0);
ret = devm_request_irq(dev, irq, mlxbf_smbus_irq,
IRQF_ONESHOT | IRQF_SHARED | IRQF_PROBE_SHARED,
dev_name(dev), priv);
if (ret < 0) {
dev_err(dev, "Cannot get irq %d\n", irq);
return ret;
}
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 int mlxbf_i2c_remove(struct platform_device *pdev)
{
struct mlxbf_i2c_priv *priv = platform_get_drvdata(pdev);
struct device *dev = &pdev->dev;
struct resource *params;
params = priv->smbus->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);
return 0;
}
static struct platform_driver mlxbf_i2c_driver = {
.probe = mlxbf_i2c_probe,
.remove = mlxbf_i2c_remove,
.driver = {
.name = "i2c-mlxbf",
.of_match_table = mlxbf_i2c_dt_ids,
#ifdef CONFIG_ACPI
.acpi_match_table = ACPI_PTR(mlxbf_i2c_acpi_ids),
#endif /* CONFIG_ACPI */
},
};
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_LICENSE("GPL v2");
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