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linux/drivers/i2c/busses/i2c-designware-core.h
Jarkko Nikula 197ecadad8 i2c: designware: Implement generic polling mode code for Wangxun 10Gb NIC 
I got an idea the i2c-designware should not need duplicated state
machines for the interrupt and polling modes. The IP is practically the
same and state transitions happens in response to the events that can be
observed from the DW_IC_RAW_INTR_STAT register. Either by interrupts or
by polling.

Another reasons are the interrupt mode is the most tested, has handling
for special cases as well as transmit abort handling and those are
missing from two polling mode quirks.

Patch implements a generic polling mode by using existing code for
interrupt mode. This is done by moving event handling from the
i2c_dw_isr() into a new i2c_dw_process_transfer() that will be called
both from the i2c_dw_isr() and a polling loop.

Polling loop is implemented in a new i2c_dw_wait_transfer() that is
shared between both modes. In interrupt mode it waits for the completion
object as before. In polling mode both completion object and
DW_IC_RAW_INTR_STAT are polled to determine completed transfer and state
transitions.

Loop tries to save power by sleeping "stetson guessed" range between
3 and 25 µS which falls between 10 cycles of High-speed mode 3.4 Mb/s
and Fast mode 400 kHz. With it the CPU usage was reduced under heavy
Fast mode I2C transfer without much increase in total transfer time but
otherwise no more effort has been put to optimize this.

I decided to convert the txgbe_i2c_dw_xfer_quirk() straight to generic
polling mode code in this patch. It doesn't have HW dependent quirks
like the amd_i2c_dw_xfer_quirk() does have and without users this patch
is needless.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
2024-02-27 01:51:35 +01:00

425 lines
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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Synopsys DesignWare I2C adapter driver.
*
* Based on the TI DAVINCI I2C adapter driver.
*
* Copyright (C) 2006 Texas Instruments.
* Copyright (C) 2007 MontaVista Software Inc.
* Copyright (C) 2009 Provigent Ltd.
*/
#include <linux/bits.h>
#include <linux/compiler_types.h>
#include <linux/completion.h>
#include <linux/dev_printk.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/types.h>
#define DW_IC_DEFAULT_FUNCTIONALITY (I2C_FUNC_I2C | \
I2C_FUNC_SMBUS_BYTE | \
I2C_FUNC_SMBUS_BYTE_DATA | \
I2C_FUNC_SMBUS_WORD_DATA | \
I2C_FUNC_SMBUS_BLOCK_DATA | \
I2C_FUNC_SMBUS_I2C_BLOCK)
#define DW_IC_CON_MASTER BIT(0)
#define DW_IC_CON_SPEED_STD (1 << 1)
#define DW_IC_CON_SPEED_FAST (2 << 1)
#define DW_IC_CON_SPEED_HIGH (3 << 1)
#define DW_IC_CON_SPEED_MASK GENMASK(2, 1)
#define DW_IC_CON_10BITADDR_SLAVE BIT(3)
#define DW_IC_CON_10BITADDR_MASTER BIT(4)
#define DW_IC_CON_RESTART_EN BIT(5)
#define DW_IC_CON_SLAVE_DISABLE BIT(6)
#define DW_IC_CON_STOP_DET_IFADDRESSED BIT(7)
#define DW_IC_CON_TX_EMPTY_CTRL BIT(8)
#define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL BIT(9)
#define DW_IC_CON_BUS_CLEAR_CTRL BIT(11)
#define DW_IC_DATA_CMD_DAT GENMASK(7, 0)
#define DW_IC_DATA_CMD_FIRST_DATA_BYTE BIT(11)
/*
* Registers offset
*/
#define DW_IC_CON 0x00
#define DW_IC_TAR 0x04
#define DW_IC_SAR 0x08
#define DW_IC_DATA_CMD 0x10
#define DW_IC_SS_SCL_HCNT 0x14
#define DW_IC_SS_SCL_LCNT 0x18
#define DW_IC_FS_SCL_HCNT 0x1c
#define DW_IC_FS_SCL_LCNT 0x20
#define DW_IC_HS_SCL_HCNT 0x24
#define DW_IC_HS_SCL_LCNT 0x28
#define DW_IC_INTR_STAT 0x2c
#define DW_IC_INTR_MASK 0x30
#define DW_IC_RAW_INTR_STAT 0x34
#define DW_IC_RX_TL 0x38
#define DW_IC_TX_TL 0x3c
#define DW_IC_CLR_INTR 0x40
#define DW_IC_CLR_RX_UNDER 0x44
#define DW_IC_CLR_RX_OVER 0x48
#define DW_IC_CLR_TX_OVER 0x4c
#define DW_IC_CLR_RD_REQ 0x50
#define DW_IC_CLR_TX_ABRT 0x54
#define DW_IC_CLR_RX_DONE 0x58
#define DW_IC_CLR_ACTIVITY 0x5c
#define DW_IC_CLR_STOP_DET 0x60
#define DW_IC_CLR_START_DET 0x64
#define DW_IC_CLR_GEN_CALL 0x68
#define DW_IC_ENABLE 0x6c
#define DW_IC_STATUS 0x70
#define DW_IC_TXFLR 0x74
#define DW_IC_RXFLR 0x78
#define DW_IC_SDA_HOLD 0x7c
#define DW_IC_TX_ABRT_SOURCE 0x80
#define DW_IC_ENABLE_STATUS 0x9c
#define DW_IC_CLR_RESTART_DET 0xa8
#define DW_IC_COMP_PARAM_1 0xf4
#define DW_IC_COMP_VERSION 0xf8
#define DW_IC_SDA_HOLD_MIN_VERS 0x3131312A /* "111*" == v1.11* */
#define DW_IC_COMP_TYPE 0xfc
#define DW_IC_COMP_TYPE_VALUE 0x44570140 /* "DW" + 0x0140 */
#define DW_IC_INTR_RX_UNDER BIT(0)
#define DW_IC_INTR_RX_OVER BIT(1)
#define DW_IC_INTR_RX_FULL BIT(2)
#define DW_IC_INTR_TX_OVER BIT(3)
#define DW_IC_INTR_TX_EMPTY BIT(4)
#define DW_IC_INTR_RD_REQ BIT(5)
#define DW_IC_INTR_TX_ABRT BIT(6)
#define DW_IC_INTR_RX_DONE BIT(7)
#define DW_IC_INTR_ACTIVITY BIT(8)
#define DW_IC_INTR_STOP_DET BIT(9)
#define DW_IC_INTR_START_DET BIT(10)
#define DW_IC_INTR_GEN_CALL BIT(11)
#define DW_IC_INTR_RESTART_DET BIT(12)
#define DW_IC_INTR_MST_ON_HOLD BIT(13)
#define DW_IC_INTR_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \
DW_IC_INTR_TX_ABRT | \
DW_IC_INTR_STOP_DET)
#define DW_IC_INTR_MASTER_MASK (DW_IC_INTR_DEFAULT_MASK | \
DW_IC_INTR_TX_EMPTY)
#define DW_IC_INTR_SLAVE_MASK (DW_IC_INTR_DEFAULT_MASK | \
DW_IC_INTR_RX_UNDER | \
DW_IC_INTR_RD_REQ)
#define DW_IC_ENABLE_ABORT BIT(1)
#define DW_IC_STATUS_ACTIVITY BIT(0)
#define DW_IC_STATUS_TFE BIT(2)
#define DW_IC_STATUS_RFNE BIT(3)
#define DW_IC_STATUS_MASTER_ACTIVITY BIT(5)
#define DW_IC_STATUS_SLAVE_ACTIVITY BIT(6)
#define DW_IC_SDA_HOLD_RX_SHIFT 16
#define DW_IC_SDA_HOLD_RX_MASK GENMASK(23, 16)
#define DW_IC_ERR_TX_ABRT 0x1
#define DW_IC_TAR_10BITADDR_MASTER BIT(12)
#define DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH (BIT(2) | BIT(3))
#define DW_IC_COMP_PARAM_1_SPEED_MODE_MASK GENMASK(3, 2)
/*
* Sofware status flags
*/
#define STATUS_ACTIVE BIT(0)
#define STATUS_WRITE_IN_PROGRESS BIT(1)
#define STATUS_READ_IN_PROGRESS BIT(2)
#define STATUS_MASK GENMASK(2, 0)
/*
* operation modes
*/
#define DW_IC_MASTER 0
#define DW_IC_SLAVE 1
/*
* Hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
*
* Only expected abort codes are listed here
* refer to the datasheet for the full list
*/
#define ABRT_7B_ADDR_NOACK 0
#define ABRT_10ADDR1_NOACK 1
#define ABRT_10ADDR2_NOACK 2
#define ABRT_TXDATA_NOACK 3
#define ABRT_GCALL_NOACK 4
#define ABRT_GCALL_READ 5
#define ABRT_SBYTE_ACKDET 7
#define ABRT_SBYTE_NORSTRT 9
#define ABRT_10B_RD_NORSTRT 10
#define ABRT_MASTER_DIS 11
#define ARB_LOST 12
#define ABRT_SLAVE_FLUSH_TXFIFO 13
#define ABRT_SLAVE_ARBLOST 14
#define ABRT_SLAVE_RD_INTX 15
#define DW_IC_TX_ABRT_7B_ADDR_NOACK BIT(ABRT_7B_ADDR_NOACK)
#define DW_IC_TX_ABRT_10ADDR1_NOACK BIT(ABRT_10ADDR1_NOACK)
#define DW_IC_TX_ABRT_10ADDR2_NOACK BIT(ABRT_10ADDR2_NOACK)
#define DW_IC_TX_ABRT_TXDATA_NOACK BIT(ABRT_TXDATA_NOACK)
#define DW_IC_TX_ABRT_GCALL_NOACK BIT(ABRT_GCALL_NOACK)
#define DW_IC_TX_ABRT_GCALL_READ BIT(ABRT_GCALL_READ)
#define DW_IC_TX_ABRT_SBYTE_ACKDET BIT(ABRT_SBYTE_ACKDET)
#define DW_IC_TX_ABRT_SBYTE_NORSTRT BIT(ABRT_SBYTE_NORSTRT)
#define DW_IC_TX_ABRT_10B_RD_NORSTRT BIT(ABRT_10B_RD_NORSTRT)
#define DW_IC_TX_ABRT_MASTER_DIS BIT(ABRT_MASTER_DIS)
#define DW_IC_TX_ARB_LOST BIT(ARB_LOST)
#define DW_IC_RX_ABRT_SLAVE_RD_INTX BIT(ABRT_SLAVE_RD_INTX)
#define DW_IC_RX_ABRT_SLAVE_ARBLOST BIT(ABRT_SLAVE_ARBLOST)
#define DW_IC_RX_ABRT_SLAVE_FLUSH_TXFIFO BIT(ABRT_SLAVE_FLUSH_TXFIFO)
#define DW_IC_TX_ABRT_NOACK (DW_IC_TX_ABRT_7B_ADDR_NOACK | \
DW_IC_TX_ABRT_10ADDR1_NOACK | \
DW_IC_TX_ABRT_10ADDR2_NOACK | \
DW_IC_TX_ABRT_TXDATA_NOACK | \
DW_IC_TX_ABRT_GCALL_NOACK)
struct clk;
struct device;
struct reset_control;
/**
* struct dw_i2c_dev - private i2c-designware data
* @dev: driver model device node
* @map: IO registers map
* @sysmap: System controller registers map
* @base: IO registers pointer
* @ext: Extended IO registers pointer
* @cmd_complete: tx completion indicator
* @clk: input reference clock
* @pclk: clock required to access the registers
* @rst: optional reset for the controller
* @slave: represent an I2C slave device
* @get_clk_rate_khz: callback to retrieve IP specific bus speed
* @cmd_err: run time hadware error code
* @msgs: points to an array of messages currently being transferred
* @msgs_num: the number of elements in msgs
* @msg_write_idx: the element index of the current tx message in the msgs array
* @tx_buf_len: the length of the current tx buffer
* @tx_buf: the current tx buffer
* @msg_read_idx: the element index of the current rx message in the msgs array
* @rx_buf_len: the length of the current rx buffer
* @rx_buf: the current rx buffer
* @msg_err: error status of the current transfer
* @status: i2c master status, one of STATUS_*
* @abort_source: copy of the TX_ABRT_SOURCE register
* @sw_mask: SW mask of DW_IC_INTR_MASK used in polling mode
* @irq: interrupt number for the i2c master
* @flags: platform specific flags like type of IO accessors or model
* @adapter: i2c subsystem adapter node
* @functionality: I2C_FUNC_* ORed bits to reflect what controller does support
* @master_cfg: configuration for the master device
* @slave_cfg: configuration for the slave device
* @tx_fifo_depth: depth of the hardware tx fifo
* @rx_fifo_depth: depth of the hardware rx fifo
* @rx_outstanding: current master-rx elements in tx fifo
* @timings: bus clock frequency, SDA hold and other timings
* @sda_hold_time: SDA hold value
* @ss_hcnt: standard speed HCNT value
* @ss_lcnt: standard speed LCNT value
* @fs_hcnt: fast speed HCNT value
* @fs_lcnt: fast speed LCNT value
* @fp_hcnt: fast plus HCNT value
* @fp_lcnt: fast plus LCNT value
* @hs_hcnt: high speed HCNT value
* @hs_lcnt: high speed LCNT value
* @acquire_lock: function to acquire a hardware lock on the bus
* @release_lock: function to release a hardware lock on the bus
* @semaphore_idx: Index of table with semaphore type attached to the bus. It's
* -1 if there is no semaphore.
* @shared_with_punit: true if this bus is shared with the SoCs PUNIT
* @disable: function to disable the controller
* @init: function to initialize the I2C hardware
* @set_sda_hold_time: callback to retrieve IP specific SDA hold timing
* @mode: operation mode - DW_IC_MASTER or DW_IC_SLAVE
* @rinfo: I²C GPIO recovery information
*
* HCNT and LCNT parameters can be used if the platform knows more accurate
* values than the one computed based only on the input clock frequency.
* Leave them to be %0 if not used.
*/
struct dw_i2c_dev {
struct device *dev;
struct regmap *map;
struct regmap *sysmap;
void __iomem *base;
void __iomem *ext;
struct completion cmd_complete;
struct clk *clk;
struct clk *pclk;
struct reset_control *rst;
struct i2c_client *slave;
u32 (*get_clk_rate_khz) (struct dw_i2c_dev *dev);
int cmd_err;
struct i2c_msg *msgs;
int msgs_num;
int msg_write_idx;
u32 tx_buf_len;
u8 *tx_buf;
int msg_read_idx;
u32 rx_buf_len;
u8 *rx_buf;
int msg_err;
unsigned int status;
unsigned int abort_source;
unsigned int sw_mask;
int irq;
u32 flags;
struct i2c_adapter adapter;
u32 functionality;
u32 master_cfg;
u32 slave_cfg;
unsigned int tx_fifo_depth;
unsigned int rx_fifo_depth;
int rx_outstanding;
struct i2c_timings timings;
u32 sda_hold_time;
u16 ss_hcnt;
u16 ss_lcnt;
u16 fs_hcnt;
u16 fs_lcnt;
u16 fp_hcnt;
u16 fp_lcnt;
u16 hs_hcnt;
u16 hs_lcnt;
int (*acquire_lock)(void);
void (*release_lock)(void);
int semaphore_idx;
bool shared_with_punit;
void (*disable)(struct dw_i2c_dev *dev);
int (*init)(struct dw_i2c_dev *dev);
int (*set_sda_hold_time)(struct dw_i2c_dev *dev);
int mode;
struct i2c_bus_recovery_info rinfo;
};
#define ACCESS_INTR_MASK BIT(0)
#define ACCESS_NO_IRQ_SUSPEND BIT(1)
#define ARBITRATION_SEMAPHORE BIT(2)
#define ACCESS_POLLING BIT(3)
#define MODEL_MSCC_OCELOT BIT(8)
#define MODEL_BAIKAL_BT1 BIT(9)
#define MODEL_AMD_NAVI_GPU BIT(10)
#define MODEL_WANGXUN_SP BIT(11)
#define MODEL_MASK GENMASK(11, 8)
/*
* Enable UCSI interrupt by writing 0xd at register
* offset 0x474 specified in hardware specification.
*/
#define AMD_UCSI_INTR_REG 0x474
#define AMD_UCSI_INTR_EN 0xd
#define TXGBE_TX_FIFO_DEPTH 4
#define TXGBE_RX_FIFO_DEPTH 1
struct i2c_dw_semaphore_callbacks {
int (*probe)(struct dw_i2c_dev *dev);
void (*remove)(struct dw_i2c_dev *dev);
};
int i2c_dw_init_regmap(struct dw_i2c_dev *dev);
u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset);
u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev);
u32 i2c_dw_clk_rate(struct dw_i2c_dev *dev);
int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare);
int i2c_dw_acquire_lock(struct dw_i2c_dev *dev);
void i2c_dw_release_lock(struct dw_i2c_dev *dev);
int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev);
int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev);
int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev);
u32 i2c_dw_func(struct i2c_adapter *adap);
void i2c_dw_disable(struct dw_i2c_dev *dev);
static inline void __i2c_dw_enable(struct dw_i2c_dev *dev)
{
dev->status |= STATUS_ACTIVE;
regmap_write(dev->map, DW_IC_ENABLE, 1);
}
static inline void __i2c_dw_disable_nowait(struct dw_i2c_dev *dev)
{
regmap_write(dev->map, DW_IC_ENABLE, 0);
dev->status &= ~STATUS_ACTIVE;
}
static inline void __i2c_dw_write_intr_mask(struct dw_i2c_dev *dev,
unsigned int intr_mask)
{
unsigned int val = dev->flags & ACCESS_POLLING ? 0 : intr_mask;
regmap_write(dev->map, DW_IC_INTR_MASK, val);
dev->sw_mask = intr_mask;
}
static inline void __i2c_dw_read_intr_mask(struct dw_i2c_dev *dev,
unsigned int *intr_mask)
{
if (!(dev->flags & ACCESS_POLLING))
regmap_read(dev->map, DW_IC_INTR_MASK, intr_mask);
else
*intr_mask = dev->sw_mask;
}
void __i2c_dw_disable(struct dw_i2c_dev *dev);
extern void i2c_dw_configure_master(struct dw_i2c_dev *dev);
extern int i2c_dw_probe_master(struct dw_i2c_dev *dev);
#if IS_ENABLED(CONFIG_I2C_DESIGNWARE_SLAVE)
extern void i2c_dw_configure_slave(struct dw_i2c_dev *dev);
extern int i2c_dw_probe_slave(struct dw_i2c_dev *dev);
#else
static inline void i2c_dw_configure_slave(struct dw_i2c_dev *dev) { }
static inline int i2c_dw_probe_slave(struct dw_i2c_dev *dev) { return -EINVAL; }
#endif
static inline int i2c_dw_probe(struct dw_i2c_dev *dev)
{
switch (dev->mode) {
case DW_IC_SLAVE:
return i2c_dw_probe_slave(dev);
case DW_IC_MASTER:
return i2c_dw_probe_master(dev);
default:
dev_err(dev->dev, "Wrong operation mode: %d\n", dev->mode);
return -EINVAL;
}
}
static inline void i2c_dw_configure(struct dw_i2c_dev *dev)
{
if (i2c_detect_slave_mode(dev->dev))
i2c_dw_configure_slave(dev);
else
i2c_dw_configure_master(dev);
}
#if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL)
int i2c_dw_baytrail_probe_lock_support(struct dw_i2c_dev *dev);
#endif
#if IS_ENABLED(CONFIG_I2C_DESIGNWARE_AMDPSP)
int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev);
#endif
int i2c_dw_validate_speed(struct dw_i2c_dev *dev);
void i2c_dw_adjust_bus_speed(struct dw_i2c_dev *dev);
#if IS_ENABLED(CONFIG_ACPI)
int i2c_dw_acpi_configure(struct device *device);
#else
static inline int i2c_dw_acpi_configure(struct device *device) { return -ENODEV; }
#endif
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