u-boot/include/i2c.h

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2002-03-10 22:37:15 +08:00
/*
* Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
* Copyright (C) 2009 - 2013 Heiko Schocher <hs@denx.de>
* Changes for multibus/multiadapter I2C support.
*
2002-03-10 22:37:15 +08:00
* (C) Copyright 2001
* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
*
* SPDX-License-Identifier: GPL-2.0+
2002-03-10 22:37:15 +08:00
*
* The original I2C interface was
* (C) 2000 by Paolo Scaffardi (arsenio@tin.it)
* AIRVENT SAM s.p.a - RIMINI(ITALY)
* but has been changed substantially.
*/
#ifndef _I2C_H_
#define _I2C_H_
/*
* For now there are essentially two parts to this file - driver model
* here at the top, and the older code below (with CONFIG_SYS_I2C being
* most recent). The plan is to migrate everything to driver model.
* The driver model structures and API are separate as they are different
* enough as to be incompatible for compilation purposes.
*/
enum dm_i2c_chip_flags {
DM_I2C_CHIP_10BIT = 1 << 0, /* Use 10-bit addressing */
DM_I2C_CHIP_RD_ADDRESS = 1 << 1, /* Send address for each read byte */
DM_I2C_CHIP_WR_ADDRESS = 1 << 2, /* Send address for each write byte */
};
struct udevice;
/**
* struct dm_i2c_chip - information about an i2c chip
*
* An I2C chip is a device on the I2C bus. It sits at a particular address
* and normally supports 7-bit or 10-bit addressing.
*
* To obtain this structure, use dev_get_parent_platdata(dev) where dev is
* the chip to examine.
*
* @chip_addr: Chip address on bus
* @offset_len: Length of offset in bytes. A single byte offset can
* represent up to 256 bytes. A value larger than 1 may be
* needed for larger devices.
* @flags: Flags for this chip (dm_i2c_chip_flags)
* @emul: Emulator for this chip address (only used for emulation)
*/
struct dm_i2c_chip {
uint chip_addr;
uint offset_len;
uint flags;
#ifdef CONFIG_SANDBOX
struct udevice *emul;
bool test_mode;
#endif
};
/**
* struct dm_i2c_bus- information about an i2c bus
*
* An I2C bus contains 0 or more chips on it, each at its own address. The
* bus can operate at different speeds (measured in Hz, typically 100KHz
* or 400KHz).
*
* To obtain this structure, use dev_get_uclass_priv(bus) where bus is the
* I2C bus udevice.
*
* @speed_hz: Bus speed in hertz (typically 100000)
*/
struct dm_i2c_bus {
int speed_hz;
};
/*
* Not all of these flags are implemented in the U-Boot API
*/
enum dm_i2c_msg_flags {
I2C_M_TEN = 0x0010, /* ten-bit chip address */
I2C_M_RD = 0x0001, /* read data, from slave to master */
I2C_M_STOP = 0x8000, /* send stop after this message */
I2C_M_NOSTART = 0x4000, /* no start before this message */
I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */
I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */
I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */
I2C_M_RECV_LEN = 0x0400, /* length is first received byte */
};
/**
* struct i2c_msg - an I2C message
*
* @addr: Slave address
* @flags: Flags (see enum dm_i2c_msg_flags)
* @len: Length of buffer in bytes, may be 0 for a probe
* @buf: Buffer to send/receive, or NULL if no data
*/
struct i2c_msg {
uint addr;
uint flags;
uint len;
u8 *buf;
};
/**
* struct i2c_msg_list - a list of I2C messages
*
* This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
* appropriate in U-Boot.
*
* @msg: Pointer to i2c_msg array
* @nmsgs: Number of elements in the array
*/
struct i2c_msg_list {
struct i2c_msg *msgs;
uint nmsgs;
};
/**
* dm_i2c_read() - read bytes from an I2C chip
*
* To obtain an I2C device (called a 'chip') given the I2C bus address you
* can use i2c_get_chip(). To obtain a bus by bus number use
* uclass_get_device_by_seq(UCLASS_I2C, <bus number>).
*
* To set the address length of a devce use i2c_set_addr_len(). It
* defaults to 1.
*
* @dev: Chip to read from
* @offset: Offset within chip to start reading
* @buffer: Place to put data
* @len: Number of bytes to read
*
* @return 0 on success, -ve on failure
*/
int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len);
/**
* dm_i2c_write() - write bytes to an I2C chip
*
* See notes for dm_i2c_read() above.
*
* @dev: Chip to write to
* @offset: Offset within chip to start writing
* @buffer: Buffer containing data to write
* @len: Number of bytes to write
*
* @return 0 on success, -ve on failure
*/
int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
int len);
/**
* dm_i2c_probe() - probe a particular chip address
*
* This can be useful to check for the existence of a chip on the bus.
* It is typically implemented by writing the chip address to the bus
* and checking that the chip replies with an ACK.
*
* @bus: Bus to probe
* @chip_addr: 7-bit address to probe (10-bit and others are not supported)
* @chip_flags: Flags for the probe (see enum dm_i2c_chip_flags)
* @devp: Returns the device found, or NULL if none
* @return 0 if a chip was found at that address, -ve if not
*/
int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
struct udevice **devp);
/**
* dm_i2c_reg_read() - Read a value from an I2C register
*
* This reads a single value from the given address in an I2C chip
*
* @dev: Device to use for transfer
* @addr: Address to read from
* @return value read, or -ve on error
*/
int dm_i2c_reg_read(struct udevice *dev, uint offset);
/**
* dm_i2c_reg_write() - Write a value to an I2C register
*
* This writes a single value to the given address in an I2C chip
*
* @dev: Device to use for transfer
* @addr: Address to write to
* @val: Value to write (normally a byte)
* @return 0 on success, -ve on error
*/
int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
/**
* dm_i2c_xfer() - Transfer messages over I2C
*
* This transfers a raw message. It is best to use dm_i2c_reg_read/write()
* instead.
*
* @dev: Device to use for transfer
* @msg: List of messages to transfer
* @nmsgs: Number of messages to transfer
* @return 0 on success, -ve on error
*/
int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs);
/**
* dm_i2c_set_bus_speed() - set the speed of a bus
*
* @bus: Bus to adjust
* @speed: Requested speed in Hz
* @return 0 if OK, -EINVAL for invalid values
*/
int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
/**
* dm_i2c_get_bus_speed() - get the speed of a bus
*
* @bus: Bus to check
* @return speed of selected I2C bus in Hz, -ve on error
*/
int dm_i2c_get_bus_speed(struct udevice *bus);
/**
* i2c_set_chip_flags() - set flags for a chip
*
* Typically addresses are 7 bits, but for 10-bit addresses you should set
* flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
*
* @dev: Chip to adjust
* @flags: New flags
* @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
*/
int i2c_set_chip_flags(struct udevice *dev, uint flags);
/**
* i2c_get_chip_flags() - get flags for a chip
*
* @dev: Chip to check
* @flagsp: Place to put flags
* @return 0 if OK, other -ve value on error
*/
int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
/**
* i2c_set_offset_len() - set the offset length for a chip
*
* The offset used to access a chip may be up to 4 bytes long. Typically it
* is only 1 byte, which is enough for chips with 256 bytes of memory or
* registers. The default value is 1, but you can call this function to
* change it.
*
* @offset_len: New offset length value (typically 1 or 2)
*/
int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
/**
* i2c_get_offset_len() - get the offset length for a chip
*
* @return: Current offset length value (typically 1 or 2)
*/
int i2c_get_chip_offset_len(struct udevice *dev);
/**
* i2c_deblock() - recover a bus that is in an unknown state
*
* See the deblock() method in 'struct dm_i2c_ops' for full information
*
* @bus: Bus to recover
* @return 0 if OK, -ve on error
*/
int i2c_deblock(struct udevice *bus);
#ifdef CONFIG_DM_I2C_COMPAT
/**
* i2c_probe() - Compatibility function for driver model
*
* Calls dm_i2c_probe() on the current bus
*/
int i2c_probe(uint8_t chip_addr);
/**
* i2c_read() - Compatibility function for driver model
*
* Calls dm_i2c_read() with the device corresponding to @chip_addr, and offset
* set to @addr. @alen must match the current setting for the device.
*/
int i2c_read(uint8_t chip_addr, unsigned int addr, int alen, uint8_t *buffer,
int len);
/**
* i2c_write() - Compatibility function for driver model
*
* Calls dm_i2c_write() with the device corresponding to @chip_addr, and offset
* set to @addr. @alen must match the current setting for the device.
*/
int i2c_write(uint8_t chip_addr, unsigned int addr, int alen, uint8_t *buffer,
int len);
/**
* i2c_get_bus_num_fdt() - Compatibility function for driver model
*
* @return the bus number associated with the given device tree node
*/
int i2c_get_bus_num_fdt(int node);
/**
* i2c_get_bus_num() - Compatibility function for driver model
*
* @return the 'current' bus number
*/
unsigned int i2c_get_bus_num(void);
/**
* i2c_set_bus_num() - Compatibility function for driver model
*
* Sets the 'current' bus
*/
int i2c_set_bus_num(unsigned int bus);
static inline void I2C_SET_BUS(unsigned int bus)
{
i2c_set_bus_num(bus);
}
static inline unsigned int I2C_GET_BUS(void)
{
return i2c_get_bus_num();
}
/**
* i2c_init() - Compatibility function for driver model
*
* This function does nothing.
*/
void i2c_init(int speed, int slaveaddr);
/**
* board_i2c_init() - Compatibility function for driver model
*
* @param blob Device tree blbo
* @return the number of I2C bus
*/
void board_i2c_init(const void *blob);
/*
* Compatibility functions for driver model.
*/
uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
#endif
/**
* struct dm_i2c_ops - driver operations for I2C uclass
*
* Drivers should support these operations unless otherwise noted. These
* operations are intended to be used by uclass code, not directly from
* other code.
*/
struct dm_i2c_ops {
/**
* xfer() - transfer a list of I2C messages
*
* @bus: Bus to read from
* @msg: List of messages to transfer
* @nmsgs: Number of messages in the list
* @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
* -ECOMM if the speed cannot be supported, -EPROTO if the chip
* flags cannot be supported, other -ve value on some other error
*/
int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
/**
* probe_chip() - probe for the presense of a chip address
*
* This function is optional. If omitted, the uclass will send a zero
* length message instead.
*
* @bus: Bus to probe
* @chip_addr: Chip address to probe
* @chip_flags: Probe flags (enum dm_i2c_chip_flags)
* @return 0 if chip was found, -EREMOTEIO if not, -ENOSYS to fall back
* to default probem other -ve value on error
*/
int (*probe_chip)(struct udevice *bus, uint chip_addr, uint chip_flags);
/**
* set_bus_speed() - set the speed of a bus (optional)
*
* The bus speed value will be updated by the uclass if this function
* does not return an error. This method is optional - if it is not
* provided then the driver can read the speed from
* dev_get_uclass_priv(bus)->speed_hz
*
* @bus: Bus to adjust
* @speed: Requested speed in Hz
* @return 0 if OK, -EINVAL for invalid values
*/
int (*set_bus_speed)(struct udevice *bus, unsigned int speed);
/**
* get_bus_speed() - get the speed of a bus (optional)
*
* Normally this can be provided by the uclass, but if you want your
* driver to check the bus speed by looking at the hardware, you can
* implement that here. This method is optional. This method would
* normally be expected to return dev_get_uclass_priv(bus)->speed_hz.
*
* @bus: Bus to check
* @return speed of selected I2C bus in Hz, -ve on error
*/
int (*get_bus_speed)(struct udevice *bus);
/**
* set_flags() - set the flags for a chip (optional)
*
* This is generally implemented by the uclass, but drivers can
* check the value to ensure that unsupported options are not used.
* This method is optional. If provided, this method will always be
* called when the flags change.
*
* @dev: Chip to adjust
* @flags: New flags value
* @return 0 if OK, -EINVAL if value is unsupported
*/
int (*set_flags)(struct udevice *dev, uint flags);
/**
* deblock() - recover a bus that is in an unknown state
*
* I2C is a synchronous protocol and resets of the processor in the
* middle of an access can block the I2C Bus until a powerdown of
* the full unit is done. This is because slaves can be stuck
* waiting for addition bus transitions for a transaction that will
* never complete. Resetting the I2C master does not help. The only
* way is to force the bus through a series of transitions to make
* sure that all slaves are done with the transaction. This method
* performs this 'deblocking' if support by the driver.
*
* This method is optional.
*/
int (*deblock)(struct udevice *bus);
};
#define i2c_get_ops(dev) ((struct dm_i2c_ops *)(dev)->driver->ops)
/**
* struct i2c_mux_ops - operations for an I2C mux
*
* The current mux state is expected to be stored in the mux itself since
* it is the only thing that knows how to make things work. The mux can
* record the current state and then avoid switching unless it is necessary.
* So select() can be skipped if the mux is already in the correct state.
* Also deselect() can be made a nop if required.
*/
struct i2c_mux_ops {
/**
* select() - select one of of I2C buses attached to a mux
*
* This will be called when there is no bus currently selected by the
* mux. This method does not need to deselect the old bus since
* deselect() will be already have been called if necessary.
*
* @mux: Mux device
* @bus: I2C bus to select
* @channel: Channel number correponding to the bus to select
* @return 0 if OK, -ve on error
*/
int (*select)(struct udevice *mux, struct udevice *bus, uint channel);
/**
* deselect() - select one of of I2C buses attached to a mux
*
* This is used to deselect the currently selected I2C bus.
*
* @mux: Mux device
* @bus: I2C bus to deselect
* @channel: Channel number correponding to the bus to deselect
* @return 0 if OK, -ve on error
*/
int (*deselect)(struct udevice *mux, struct udevice *bus, uint channel);
};
#define i2c_mux_get_ops(dev) ((struct i2c_mux_ops *)(dev)->driver->ops)
/**
* i2c_get_chip() - get a device to use to access a chip on a bus
*
* This returns the device for the given chip address. The device can then
* be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc.
*
* @bus: Bus to examine
* @chip_addr: Chip address for the new device
* @offset_len: Length of a register offset in bytes (normally 1)
* @devp: Returns pointer to new device if found or -ENODEV if not
* found
*/
int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
struct udevice **devp);
/**
* i2c_get_chip_for_busnum() - get a device to use to access a chip on
* a bus number
*
* This returns the device for the given chip address on a particular bus
* number.
*
* @busnum: Bus number to examine
* @chip_addr: Chip address for the new device
* @offset_len: Length of a register offset in bytes (normally 1)
* @devp: Returns pointer to new device if found or -ENODEV if not
* found
*/
int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
struct udevice **devp);
/**
* i2c_chip_ofdata_to_platdata() - Decode standard I2C platform data
*
* This decodes the chip address from a device tree node and puts it into
* its dm_i2c_chip structure. This should be called in your driver's
* ofdata_to_platdata() method.
*
* @blob: Device tree blob
* @node: Node offset to read from
* @spi: Place to put the decoded information
*/
int i2c_chip_ofdata_to_platdata(struct udevice *dev, struct dm_i2c_chip *chip);
/**
* i2c_dump_msgs() - Dump a list of I2C messages
*
* This may be useful for debugging.
*
* @msg: Message list to dump
* @nmsgs: Number of messages
*/
void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs);
#ifndef CONFIG_DM_I2C
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/*
* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
*
* The implementation MUST NOT use static or global variables if the
* I2C routines are used to read SDRAM configuration information
* because this is done before the memories are initialized. Limited
* use of stack-based variables are OK (the initial stack size is
* limited).
*
* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
*/
/*
* Configuration items.
*/
#define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
#if !defined(CONFIG_SYS_I2C_MAX_HOPS)
/* no muxes used bus = i2c adapters */
#define CONFIG_SYS_I2C_DIRECT_BUS 1
#define CONFIG_SYS_I2C_MAX_HOPS 0
#define CONFIG_SYS_NUM_I2C_BUSES ll_entry_count(struct i2c_adapter, i2c)
#else
/* we use i2c muxes */
#undef CONFIG_SYS_I2C_DIRECT_BUS
#endif
/* define the I2C bus number for RTC and DTT if not already done */
#if !defined(CONFIG_SYS_RTC_BUS_NUM)
#define CONFIG_SYS_RTC_BUS_NUM 0
#endif
#if !defined(CONFIG_SYS_SPD_BUS_NUM)
#define CONFIG_SYS_SPD_BUS_NUM 0
#endif
struct i2c_adapter {
void (*init)(struct i2c_adapter *adap, int speed,
int slaveaddr);
int (*probe)(struct i2c_adapter *adap, uint8_t chip);
int (*read)(struct i2c_adapter *adap, uint8_t chip,
uint addr, int alen, uint8_t *buffer,
int len);
int (*write)(struct i2c_adapter *adap, uint8_t chip,
uint addr, int alen, uint8_t *buffer,
int len);
uint (*set_bus_speed)(struct i2c_adapter *adap,
uint speed);
int speed;
int waitdelay;
int slaveaddr;
int init_done;
int hwadapnr;
char *name;
};
#define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
_set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
{ \
.init = _init, \
.probe = _probe, \
.read = _read, \
.write = _write, \
.set_bus_speed = _set_speed, \
.speed = _speed, \
.slaveaddr = _slaveaddr, \
.init_done = 0, \
.hwadapnr = _hwadapnr, \
.name = #_name \
};
#define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
_set_speed, _speed, _slaveaddr, _hwadapnr) \
ll_entry_declare(struct i2c_adapter, _name, i2c) = \
U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
_set_speed, _speed, _slaveaddr, _hwadapnr, _name);
struct i2c_adapter *i2c_get_adapter(int index);
#ifndef CONFIG_SYS_I2C_DIRECT_BUS
struct i2c_mux {
int id;
char name[16];
};
struct i2c_next_hop {
struct i2c_mux mux;
uint8_t chip;
uint8_t channel;
};
struct i2c_bus_hose {
int adapter;
struct i2c_next_hop next_hop[CONFIG_SYS_I2C_MAX_HOPS];
};
#define I2C_NULL_HOP {{-1, ""}, 0, 0}
extern struct i2c_bus_hose i2c_bus[];
#define I2C_ADAPTER(bus) i2c_bus[bus].adapter
#else
#define I2C_ADAPTER(bus) bus
#endif
#define I2C_BUS gd->cur_i2c_bus
#define I2C_ADAP_NR(bus) i2c_get_adapter(I2C_ADAPTER(bus))
#define I2C_ADAP I2C_ADAP_NR(gd->cur_i2c_bus)
#define I2C_ADAP_HWNR (I2C_ADAP->hwadapnr)
#ifndef CONFIG_SYS_I2C_DIRECT_BUS
#define I2C_MUX_PCA9540_ID 1
#define I2C_MUX_PCA9540 {I2C_MUX_PCA9540_ID, "PCA9540B"}
#define I2C_MUX_PCA9542_ID 2
#define I2C_MUX_PCA9542 {I2C_MUX_PCA9542_ID, "PCA9542A"}
#define I2C_MUX_PCA9544_ID 3
#define I2C_MUX_PCA9544 {I2C_MUX_PCA9544_ID, "PCA9544A"}
#define I2C_MUX_PCA9547_ID 4
#define I2C_MUX_PCA9547 {I2C_MUX_PCA9547_ID, "PCA9547A"}
#define I2C_MUX_PCA9548_ID 5
#define I2C_MUX_PCA9548 {I2C_MUX_PCA9548_ID, "PCA9548"}
#endif
#ifndef I2C_SOFT_DECLARATIONS
# if (defined(CONFIG_AT91RM9200) || \
defined(CONFIG_AT91SAM9260) || defined(CONFIG_AT91SAM9261) || \
defined(CONFIG_AT91SAM9263))
# define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) ATMEL_BASE_PIOA;
# else
# define I2C_SOFT_DECLARATIONS
# endif
#endif
/*
* Many boards/controllers/drivers don't support an I2C slave interface so
* provide a default slave address for them for use in common code. A real
* value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
* support a slave interface.
*/
#ifndef CONFIG_SYS_I2C_SLAVE
#define CONFIG_SYS_I2C_SLAVE 0xfe
#endif
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/*
* Initialization, must be called once on start up, may be called
* repeatedly to change the speed and slave addresses.
*/
#ifdef CONFIG_SYS_I2C_EARLY_INIT
void i2c_early_init_f(void);
#endif
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void i2c_init(int speed, int slaveaddr);
void i2c_init_board(void);
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#ifdef CONFIG_SYS_I2C
/*
* i2c_get_bus_num:
*
* Returns index of currently active I2C bus. Zero-based.
*/
unsigned int i2c_get_bus_num(void);
/*
* i2c_set_bus_num:
*
* Change the active I2C bus. Subsequent read/write calls will
* go to this one.
*
* bus - bus index, zero based
*
* Returns: 0 on success, not 0 on failure
*
*/
int i2c_set_bus_num(unsigned int bus);
/*
* i2c_init_all():
*
* Initializes all I2C adapters in the system. All i2c_adap structures must
* be initialized beforehead with function pointers and data, including
* speed and slaveaddr. Returns 0 on success, non-0 on failure.
*/
void i2c_init_all(void);
/*
* Probe the given I2C chip address. Returns 0 if a chip responded,
* not 0 on failure.
*/
int i2c_probe(uint8_t chip);
/*
* Read/Write interface:
* chip: I2C chip address, range 0..127
* addr: Memory (register) address within the chip
* alen: Number of bytes to use for addr (typically 1, 2 for larger
* memories, 0 for register type devices with only one
* register)
* buffer: Where to read/write the data
* len: How many bytes to read/write
*
* Returns: 0 on success, not 0 on failure
*/
int i2c_read(uint8_t chip, unsigned int addr, int alen,
uint8_t *buffer, int len);
int i2c_write(uint8_t chip, unsigned int addr, int alen,
uint8_t *buffer, int len);
/*
* Utility routines to read/write registers.
*/
uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
/*
* i2c_set_bus_speed:
*
* Change the speed of the active I2C bus
*
* speed - bus speed in Hz
*
* Returns: new bus speed
*
*/
unsigned int i2c_set_bus_speed(unsigned int speed);
/*
* i2c_get_bus_speed:
*
* Returns speed of currently active I2C bus in Hz
*/
unsigned int i2c_get_bus_speed(void);
#else
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/*
* Probe the given I2C chip address. Returns 0 if a chip responded,
* not 0 on failure.
*/
int i2c_probe(uchar chip);
/*
* Read/Write interface:
* chip: I2C chip address, range 0..127
* addr: Memory (register) address within the chip
* alen: Number of bytes to use for addr (typically 1, 2 for larger
* memories, 0 for register type devices with only one
* register)
* buffer: Where to read/write the data
* len: How many bytes to read/write
*
* Returns: 0 on success, not 0 on failure
*/
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
/*
* Utility routines to read/write registers.
*/
static inline u8 i2c_reg_read(u8 addr, u8 reg)
{
u8 buf;
#ifdef DEBUG
printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
#endif
i2c_read(addr, reg, 1, &buf, 1);
return buf;
}
static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
{
#ifdef DEBUG
printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
__func__, addr, reg, val);
#endif
i2c_write(addr, reg, 1, &val, 1);
}
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/*
* Functions for setting the current I2C bus and its speed
*/
/*
* i2c_set_bus_num:
*
* Change the active I2C bus. Subsequent read/write calls will
* go to this one.
*
* bus - bus index, zero based
*
* Returns: 0 on success, not 0 on failure
*
*/
int i2c_set_bus_num(unsigned int bus);
/*
* i2c_get_bus_num:
*
* Returns index of currently active I2C bus. Zero-based.
*/
unsigned int i2c_get_bus_num(void);
/*
* i2c_set_bus_speed:
*
* Change the speed of the active I2C bus
*
* speed - bus speed in Hz
*
* Returns: 0 on success, not 0 on failure
*
*/
int i2c_set_bus_speed(unsigned int);
/*
* i2c_get_bus_speed:
*
* Returns speed of currently active I2C bus in Hz
*/
unsigned int i2c_get_bus_speed(void);
#endif /* CONFIG_SYS_I2C */
/*
* only for backwardcompatibility, should go away if we switched
* completely to new multibus support.
*/
#if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)
# if !defined(CONFIG_SYS_MAX_I2C_BUS)
# define CONFIG_SYS_MAX_I2C_BUS 2
# endif
# define I2C_MULTI_BUS 1
#else
# define CONFIG_SYS_MAX_I2C_BUS 1
# define I2C_MULTI_BUS 0
#endif
/* NOTE: These two functions MUST be always_inline to avoid code growth! */
static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
static inline unsigned int I2C_GET_BUS(void)
{
return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
}
static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
static inline void I2C_SET_BUS(unsigned int bus)
{
if (I2C_MULTI_BUS)
i2c_set_bus_num(bus);
}
/* Multi I2C definitions */
enum {
I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
I2C_8, I2C_9, I2C_10,
};
/**
* Get FDT values for i2c bus.
*
* @param blob Device tree blbo
* @return the number of I2C bus
*/
void board_i2c_init(const void *blob);
/**
* Find the I2C bus number by given a FDT I2C node.
*
* @param blob Device tree blbo
* @param node FDT I2C node to find
* @return the number of I2C bus (zero based), or -1 on error
*/
int i2c_get_bus_num_fdt(int node);
/**
* Reset the I2C bus represented by the given a FDT I2C node.
*
* @param blob Device tree blbo
* @param node FDT I2C node to find
* @return 0 if port was reset, -1 if not found
*/
int i2c_reset_port_fdt(const void *blob, int node);
#endif /* !CONFIG_DM_I2C */
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#endif /* _I2C_H_ */