]>
git.ipfire.org Git - thirdparty/u-boot.git/blob - include/i2c.h
1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
4 * Copyright (C) 2009 - 2013 Heiko Schocher <hs@denx.de>
5 * Changes for multibus/multiadapter I2C support.
8 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
10 * The original I2C interface was
11 * (C) 2000 by Paolo Scaffardi (arsenio@tin.it)
12 * AIRVENT SAM s.p.a - RIMINI(ITALY)
13 * but has been changed substantially.
20 * For now there are essentially two parts to this file - driver model
21 * here at the top, and the older code below (with CONFIG_SYS_I2C being
22 * most recent). The plan is to migrate everything to driver model.
23 * The driver model structures and API are separate as they are different
24 * enough as to be incompatible for compilation purposes.
27 enum dm_i2c_chip_flags
{
28 DM_I2C_CHIP_10BIT
= 1 << 0, /* Use 10-bit addressing */
29 DM_I2C_CHIP_RD_ADDRESS
= 1 << 1, /* Send address for each read byte */
30 DM_I2C_CHIP_WR_ADDRESS
= 1 << 2, /* Send address for each write byte */
35 * struct dm_i2c_chip - information about an i2c chip
37 * An I2C chip is a device on the I2C bus. It sits at a particular address
38 * and normally supports 7-bit or 10-bit addressing.
40 * To obtain this structure, use dev_get_parent_platdata(dev) where dev is
41 * the chip to examine.
43 * @chip_addr: Chip address on bus
44 * @offset_len: Length of offset in bytes. A single byte offset can
45 * represent up to 256 bytes. A value larger than 1 may be
46 * needed for larger devices.
47 * @flags: Flags for this chip (dm_i2c_chip_flags)
48 * @emul: Emulator for this chip address (only used for emulation)
61 * struct dm_i2c_bus- information about an i2c bus
63 * An I2C bus contains 0 or more chips on it, each at its own address. The
64 * bus can operate at different speeds (measured in Hz, typically 100KHz
67 * To obtain this structure, use dev_get_uclass_priv(bus) where bus is the
70 * @speed_hz: Bus speed in hertz (typically 100000)
77 * Not all of these flags are implemented in the U-Boot API
79 enum dm_i2c_msg_flags
{
80 I2C_M_TEN
= 0x0010, /* ten-bit chip address */
81 I2C_M_RD
= 0x0001, /* read data, from slave to master */
82 I2C_M_STOP
= 0x8000, /* send stop after this message */
83 I2C_M_NOSTART
= 0x4000, /* no start before this message */
84 I2C_M_REV_DIR_ADDR
= 0x2000, /* invert polarity of R/W bit */
85 I2C_M_IGNORE_NAK
= 0x1000, /* continue after NAK */
86 I2C_M_NO_RD_ACK
= 0x0800, /* skip the Ack bit on reads */
87 I2C_M_RECV_LEN
= 0x0400, /* length is first received byte */
91 * struct i2c_msg - an I2C message
93 * @addr: Slave address
94 * @flags: Flags (see enum dm_i2c_msg_flags)
95 * @len: Length of buffer in bytes, may be 0 for a probe
96 * @buf: Buffer to send/receive, or NULL if no data
106 * struct i2c_msg_list - a list of I2C messages
108 * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
109 * appropriate in U-Boot.
111 * @msg: Pointer to i2c_msg array
112 * @nmsgs: Number of elements in the array
114 struct i2c_msg_list
{
115 struct i2c_msg
*msgs
;
120 * dm_i2c_read() - read bytes from an I2C chip
122 * To obtain an I2C device (called a 'chip') given the I2C bus address you
123 * can use i2c_get_chip(). To obtain a bus by bus number use
124 * uclass_get_device_by_seq(UCLASS_I2C, <bus number>).
126 * To set the address length of a devce use i2c_set_addr_len(). It
129 * @dev: Chip to read from
130 * @offset: Offset within chip to start reading
131 * @buffer: Place to put data
132 * @len: Number of bytes to read
134 * @return 0 on success, -ve on failure
136 int dm_i2c_read(struct udevice
*dev
, uint offset
, uint8_t *buffer
, int len
);
139 * dm_i2c_write() - write bytes to an I2C chip
141 * See notes for dm_i2c_read() above.
143 * @dev: Chip to write to
144 * @offset: Offset within chip to start writing
145 * @buffer: Buffer containing data to write
146 * @len: Number of bytes to write
148 * @return 0 on success, -ve on failure
150 int dm_i2c_write(struct udevice
*dev
, uint offset
, const uint8_t *buffer
,
154 * dm_i2c_probe() - probe a particular chip address
156 * This can be useful to check for the existence of a chip on the bus.
157 * It is typically implemented by writing the chip address to the bus
158 * and checking that the chip replies with an ACK.
161 * @chip_addr: 7-bit address to probe (10-bit and others are not supported)
162 * @chip_flags: Flags for the probe (see enum dm_i2c_chip_flags)
163 * @devp: Returns the device found, or NULL if none
164 * @return 0 if a chip was found at that address, -ve if not
166 int dm_i2c_probe(struct udevice
*bus
, uint chip_addr
, uint chip_flags
,
167 struct udevice
**devp
);
170 * dm_i2c_reg_read() - Read a value from an I2C register
172 * This reads a single value from the given address in an I2C chip
174 * @dev: Device to use for transfer
175 * @addr: Address to read from
176 * @return value read, or -ve on error
178 int dm_i2c_reg_read(struct udevice
*dev
, uint offset
);
181 * dm_i2c_reg_write() - Write a value to an I2C register
183 * This writes a single value to the given address in an I2C chip
185 * @dev: Device to use for transfer
186 * @addr: Address to write to
187 * @val: Value to write (normally a byte)
188 * @return 0 on success, -ve on error
190 int dm_i2c_reg_write(struct udevice
*dev
, uint offset
, unsigned int val
);
193 * dm_i2c_xfer() - Transfer messages over I2C
195 * This transfers a raw message. It is best to use dm_i2c_reg_read/write()
198 * @dev: Device to use for transfer
199 * @msg: List of messages to transfer
200 * @nmsgs: Number of messages to transfer
201 * @return 0 on success, -ve on error
203 int dm_i2c_xfer(struct udevice
*dev
, struct i2c_msg
*msg
, int nmsgs
);
206 * dm_i2c_set_bus_speed() - set the speed of a bus
208 * @bus: Bus to adjust
209 * @speed: Requested speed in Hz
210 * @return 0 if OK, -EINVAL for invalid values
212 int dm_i2c_set_bus_speed(struct udevice
*bus
, unsigned int speed
);
215 * dm_i2c_get_bus_speed() - get the speed of a bus
218 * @return speed of selected I2C bus in Hz, -ve on error
220 int dm_i2c_get_bus_speed(struct udevice
*bus
);
223 * i2c_set_chip_flags() - set flags for a chip
225 * Typically addresses are 7 bits, but for 10-bit addresses you should set
226 * flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
228 * @dev: Chip to adjust
230 * @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
232 int i2c_set_chip_flags(struct udevice
*dev
, uint flags
);
235 * i2c_get_chip_flags() - get flags for a chip
237 * @dev: Chip to check
238 * @flagsp: Place to put flags
239 * @return 0 if OK, other -ve value on error
241 int i2c_get_chip_flags(struct udevice
*dev
, uint
*flagsp
);
244 * i2c_set_offset_len() - set the offset length for a chip
246 * The offset used to access a chip may be up to 4 bytes long. Typically it
247 * is only 1 byte, which is enough for chips with 256 bytes of memory or
248 * registers. The default value is 1, but you can call this function to
251 * @offset_len: New offset length value (typically 1 or 2)
253 int i2c_set_chip_offset_len(struct udevice
*dev
, uint offset_len
);
256 * i2c_get_offset_len() - get the offset length for a chip
258 * @return: Current offset length value (typically 1 or 2)
260 int i2c_get_chip_offset_len(struct udevice
*dev
);
263 * i2c_deblock() - recover a bus that is in an unknown state
265 * See the deblock() method in 'struct dm_i2c_ops' for full information
267 * @bus: Bus to recover
268 * @return 0 if OK, -ve on error
270 int i2c_deblock(struct udevice
*bus
);
272 #ifdef CONFIG_DM_I2C_COMPAT
274 * i2c_probe() - Compatibility function for driver model
276 * Calls dm_i2c_probe() on the current bus
278 int i2c_probe(uint8_t chip_addr
);
281 * i2c_read() - Compatibility function for driver model
283 * Calls dm_i2c_read() with the device corresponding to @chip_addr, and offset
284 * set to @addr. @alen must match the current setting for the device.
286 int i2c_read(uint8_t chip_addr
, unsigned int addr
, int alen
, uint8_t *buffer
,
290 * i2c_write() - Compatibility function for driver model
292 * Calls dm_i2c_write() with the device corresponding to @chip_addr, and offset
293 * set to @addr. @alen must match the current setting for the device.
295 int i2c_write(uint8_t chip_addr
, unsigned int addr
, int alen
, uint8_t *buffer
,
299 * i2c_get_bus_num_fdt() - Compatibility function for driver model
301 * @return the bus number associated with the given device tree node
303 int i2c_get_bus_num_fdt(int node
);
306 * i2c_get_bus_num() - Compatibility function for driver model
308 * @return the 'current' bus number
310 unsigned int i2c_get_bus_num(void);
313 * i2c_set_bus_num() - Compatibility function for driver model
315 * Sets the 'current' bus
317 int i2c_set_bus_num(unsigned int bus
);
319 static inline void I2C_SET_BUS(unsigned int bus
)
321 i2c_set_bus_num(bus
);
324 static inline unsigned int I2C_GET_BUS(void)
326 return i2c_get_bus_num();
330 * i2c_init() - Compatibility function for driver model
332 * This function does nothing.
334 void i2c_init(int speed
, int slaveaddr
);
337 * board_i2c_init() - Compatibility function for driver model
339 * @param blob Device tree blbo
340 * @return the number of I2C bus
342 void board_i2c_init(const void *blob
);
345 * Compatibility functions for driver model.
347 uint8_t i2c_reg_read(uint8_t addr
, uint8_t reg
);
348 void i2c_reg_write(uint8_t addr
, uint8_t reg
, uint8_t val
);
353 * struct dm_i2c_ops - driver operations for I2C uclass
355 * Drivers should support these operations unless otherwise noted. These
356 * operations are intended to be used by uclass code, not directly from
361 * xfer() - transfer a list of I2C messages
363 * @bus: Bus to read from
364 * @msg: List of messages to transfer
365 * @nmsgs: Number of messages in the list
366 * @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
367 * -ECOMM if the speed cannot be supported, -EPROTO if the chip
368 * flags cannot be supported, other -ve value on some other error
370 int (*xfer
)(struct udevice
*bus
, struct i2c_msg
*msg
, int nmsgs
);
373 * probe_chip() - probe for the presense of a chip address
375 * This function is optional. If omitted, the uclass will send a zero
376 * length message instead.
379 * @chip_addr: Chip address to probe
380 * @chip_flags: Probe flags (enum dm_i2c_chip_flags)
381 * @return 0 if chip was found, -EREMOTEIO if not, -ENOSYS to fall back
382 * to default probem other -ve value on error
384 int (*probe_chip
)(struct udevice
*bus
, uint chip_addr
, uint chip_flags
);
387 * set_bus_speed() - set the speed of a bus (optional)
389 * The bus speed value will be updated by the uclass if this function
390 * does not return an error. This method is optional - if it is not
391 * provided then the driver can read the speed from
392 * dev_get_uclass_priv(bus)->speed_hz
394 * @bus: Bus to adjust
395 * @speed: Requested speed in Hz
396 * @return 0 if OK, -EINVAL for invalid values
398 int (*set_bus_speed
)(struct udevice
*bus
, unsigned int speed
);
401 * get_bus_speed() - get the speed of a bus (optional)
403 * Normally this can be provided by the uclass, but if you want your
404 * driver to check the bus speed by looking at the hardware, you can
405 * implement that here. This method is optional. This method would
406 * normally be expected to return dev_get_uclass_priv(bus)->speed_hz.
409 * @return speed of selected I2C bus in Hz, -ve on error
411 int (*get_bus_speed
)(struct udevice
*bus
);
414 * set_flags() - set the flags for a chip (optional)
416 * This is generally implemented by the uclass, but drivers can
417 * check the value to ensure that unsupported options are not used.
418 * This method is optional. If provided, this method will always be
419 * called when the flags change.
421 * @dev: Chip to adjust
422 * @flags: New flags value
423 * @return 0 if OK, -EINVAL if value is unsupported
425 int (*set_flags
)(struct udevice
*dev
, uint flags
);
428 * deblock() - recover a bus that is in an unknown state
430 * I2C is a synchronous protocol and resets of the processor in the
431 * middle of an access can block the I2C Bus until a powerdown of
432 * the full unit is done. This is because slaves can be stuck
433 * waiting for addition bus transitions for a transaction that will
434 * never complete. Resetting the I2C master does not help. The only
435 * way is to force the bus through a series of transitions to make
436 * sure that all slaves are done with the transaction. This method
437 * performs this 'deblocking' if support by the driver.
439 * This method is optional.
441 int (*deblock
)(struct udevice
*bus
);
444 #define i2c_get_ops(dev) ((struct dm_i2c_ops *)(dev)->driver->ops)
447 * struct i2c_mux_ops - operations for an I2C mux
449 * The current mux state is expected to be stored in the mux itself since
450 * it is the only thing that knows how to make things work. The mux can
451 * record the current state and then avoid switching unless it is necessary.
452 * So select() can be skipped if the mux is already in the correct state.
453 * Also deselect() can be made a nop if required.
457 * select() - select one of of I2C buses attached to a mux
459 * This will be called when there is no bus currently selected by the
460 * mux. This method does not need to deselect the old bus since
461 * deselect() will be already have been called if necessary.
464 * @bus: I2C bus to select
465 * @channel: Channel number correponding to the bus to select
466 * @return 0 if OK, -ve on error
468 int (*select
)(struct udevice
*mux
, struct udevice
*bus
, uint channel
);
471 * deselect() - select one of of I2C buses attached to a mux
473 * This is used to deselect the currently selected I2C bus.
476 * @bus: I2C bus to deselect
477 * @channel: Channel number correponding to the bus to deselect
478 * @return 0 if OK, -ve on error
480 int (*deselect
)(struct udevice
*mux
, struct udevice
*bus
, uint channel
);
483 #define i2c_mux_get_ops(dev) ((struct i2c_mux_ops *)(dev)->driver->ops)
486 * i2c_get_chip() - get a device to use to access a chip on a bus
488 * This returns the device for the given chip address. The device can then
489 * be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc.
491 * @bus: Bus to examine
492 * @chip_addr: Chip address for the new device
493 * @offset_len: Length of a register offset in bytes (normally 1)
494 * @devp: Returns pointer to new device if found or -ENODEV if not
497 int i2c_get_chip(struct udevice
*bus
, uint chip_addr
, uint offset_len
,
498 struct udevice
**devp
);
501 * i2c_get_chip_for_busnum() - get a device to use to access a chip on
504 * This returns the device for the given chip address on a particular bus
507 * @busnum: Bus number to examine
508 * @chip_addr: Chip address for the new device
509 * @offset_len: Length of a register offset in bytes (normally 1)
510 * @devp: Returns pointer to new device if found or -ENODEV if not
513 int i2c_get_chip_for_busnum(int busnum
, int chip_addr
, uint offset_len
,
514 struct udevice
**devp
);
517 * i2c_chip_ofdata_to_platdata() - Decode standard I2C platform data
519 * This decodes the chip address from a device tree node and puts it into
520 * its dm_i2c_chip structure. This should be called in your driver's
521 * ofdata_to_platdata() method.
523 * @blob: Device tree blob
524 * @node: Node offset to read from
525 * @spi: Place to put the decoded information
527 int i2c_chip_ofdata_to_platdata(struct udevice
*dev
, struct dm_i2c_chip
*chip
);
530 * i2c_dump_msgs() - Dump a list of I2C messages
532 * This may be useful for debugging.
534 * @msg: Message list to dump
535 * @nmsgs: Number of messages
537 void i2c_dump_msgs(struct i2c_msg
*msg
, int nmsgs
);
539 #ifndef CONFIG_DM_I2C
542 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
544 * The implementation MUST NOT use static or global variables if the
545 * I2C routines are used to read SDRAM configuration information
546 * because this is done before the memories are initialized. Limited
547 * use of stack-based variables are OK (the initial stack size is
550 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
554 * Configuration items.
556 #define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
558 #if !defined(CONFIG_SYS_I2C_MAX_HOPS)
559 /* no muxes used bus = i2c adapters */
560 #define CONFIG_SYS_I2C_DIRECT_BUS 1
561 #define CONFIG_SYS_I2C_MAX_HOPS 0
562 #define CONFIG_SYS_NUM_I2C_BUSES ll_entry_count(struct i2c_adapter, i2c)
564 /* we use i2c muxes */
565 #undef CONFIG_SYS_I2C_DIRECT_BUS
568 /* define the I2C bus number for RTC and DTT if not already done */
569 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
570 #define CONFIG_SYS_RTC_BUS_NUM 0
572 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
573 #define CONFIG_SYS_SPD_BUS_NUM 0
577 void (*init
)(struct i2c_adapter
*adap
, int speed
,
579 int (*probe
)(struct i2c_adapter
*adap
, uint8_t chip
);
580 int (*read
)(struct i2c_adapter
*adap
, uint8_t chip
,
581 uint addr
, int alen
, uint8_t *buffer
,
583 int (*write
)(struct i2c_adapter
*adap
, uint8_t chip
,
584 uint addr
, int alen
, uint8_t *buffer
,
586 uint (*set_bus_speed
)(struct i2c_adapter
*adap
,
596 #define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
597 _set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
603 .set_bus_speed = _set_speed, \
605 .slaveaddr = _slaveaddr, \
607 .hwadapnr = _hwadapnr, \
611 #define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
612 _set_speed, _speed, _slaveaddr, _hwadapnr) \
613 ll_entry_declare(struct i2c_adapter, _name, i2c) = \
614 U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
615 _set_speed, _speed, _slaveaddr, _hwadapnr, _name);
617 struct i2c_adapter
*i2c_get_adapter(int index
);
619 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
625 struct i2c_next_hop
{
631 struct i2c_bus_hose
{
633 struct i2c_next_hop next_hop
[CONFIG_SYS_I2C_MAX_HOPS
];
635 #define I2C_NULL_HOP {{-1, ""}, 0, 0}
636 extern struct i2c_bus_hose i2c_bus
[];
638 #define I2C_ADAPTER(bus) i2c_bus[bus].adapter
640 #define I2C_ADAPTER(bus) bus
642 #define I2C_BUS gd->cur_i2c_bus
644 #define I2C_ADAP_NR(bus) i2c_get_adapter(I2C_ADAPTER(bus))
645 #define I2C_ADAP I2C_ADAP_NR(gd->cur_i2c_bus)
646 #define I2C_ADAP_HWNR (I2C_ADAP->hwadapnr)
648 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
649 #define I2C_MUX_PCA9540_ID 1
650 #define I2C_MUX_PCA9540 {I2C_MUX_PCA9540_ID, "PCA9540B"}
651 #define I2C_MUX_PCA9542_ID 2
652 #define I2C_MUX_PCA9542 {I2C_MUX_PCA9542_ID, "PCA9542A"}
653 #define I2C_MUX_PCA9544_ID 3
654 #define I2C_MUX_PCA9544 {I2C_MUX_PCA9544_ID, "PCA9544A"}
655 #define I2C_MUX_PCA9547_ID 4
656 #define I2C_MUX_PCA9547 {I2C_MUX_PCA9547_ID, "PCA9547A"}
657 #define I2C_MUX_PCA9548_ID 5
658 #define I2C_MUX_PCA9548 {I2C_MUX_PCA9548_ID, "PCA9548"}
661 #ifndef I2C_SOFT_DECLARATIONS
662 # if (defined(CONFIG_AT91RM9200) || \
663 defined(CONFIG_AT91SAM9260) || defined(CONFIG_AT91SAM9261) || \
664 defined(CONFIG_AT91SAM9263))
665 # define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) ATMEL_BASE_PIOA;
667 # define I2C_SOFT_DECLARATIONS
672 * Many boards/controllers/drivers don't support an I2C slave interface so
673 * provide a default slave address for them for use in common code. A real
674 * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
675 * support a slave interface.
677 #ifndef CONFIG_SYS_I2C_SLAVE
678 #define CONFIG_SYS_I2C_SLAVE 0xfe
682 * Initialization, must be called once on start up, may be called
683 * repeatedly to change the speed and slave addresses.
685 #ifdef CONFIG_SYS_I2C_EARLY_INIT
686 void i2c_early_init_f(void);
688 void i2c_init(int speed
, int slaveaddr
);
689 void i2c_init_board(void);
691 #ifdef CONFIG_SYS_I2C
695 * Returns index of currently active I2C bus. Zero-based.
697 unsigned int i2c_get_bus_num(void);
702 * Change the active I2C bus. Subsequent read/write calls will
705 * bus - bus index, zero based
707 * Returns: 0 on success, not 0 on failure
710 int i2c_set_bus_num(unsigned int bus
);
715 * Initializes all I2C adapters in the system. All i2c_adap structures must
716 * be initialized beforehead with function pointers and data, including
717 * speed and slaveaddr. Returns 0 on success, non-0 on failure.
719 void i2c_init_all(void);
722 * Probe the given I2C chip address. Returns 0 if a chip responded,
725 int i2c_probe(uint8_t chip
);
728 * Read/Write interface:
729 * chip: I2C chip address, range 0..127
730 * addr: Memory (register) address within the chip
731 * alen: Number of bytes to use for addr (typically 1, 2 for larger
732 * memories, 0 for register type devices with only one
734 * buffer: Where to read/write the data
735 * len: How many bytes to read/write
737 * Returns: 0 on success, not 0 on failure
739 int i2c_read(uint8_t chip
, unsigned int addr
, int alen
,
740 uint8_t *buffer
, int len
);
742 int i2c_write(uint8_t chip
, unsigned int addr
, int alen
,
743 uint8_t *buffer
, int len
);
746 * Utility routines to read/write registers.
748 uint8_t i2c_reg_read(uint8_t addr
, uint8_t reg
);
750 void i2c_reg_write(uint8_t addr
, uint8_t reg
, uint8_t val
);
755 * Change the speed of the active I2C bus
757 * speed - bus speed in Hz
759 * Returns: new bus speed
762 unsigned int i2c_set_bus_speed(unsigned int speed
);
767 * Returns speed of currently active I2C bus in Hz
770 unsigned int i2c_get_bus_speed(void);
775 * Probe the given I2C chip address. Returns 0 if a chip responded,
778 int i2c_probe(uchar chip
);
781 * Read/Write interface:
782 * chip: I2C chip address, range 0..127
783 * addr: Memory (register) address within the chip
784 * alen: Number of bytes to use for addr (typically 1, 2 for larger
785 * memories, 0 for register type devices with only one
787 * buffer: Where to read/write the data
788 * len: How many bytes to read/write
790 * Returns: 0 on success, not 0 on failure
792 int i2c_read(uchar chip
, uint addr
, int alen
, uchar
*buffer
, int len
);
793 int i2c_write(uchar chip
, uint addr
, int alen
, uchar
*buffer
, int len
);
796 * Utility routines to read/write registers.
798 static inline u8
i2c_reg_read(u8 addr
, u8 reg
)
803 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__
, addr
, reg
);
806 i2c_read(addr
, reg
, 1, &buf
, 1);
811 static inline void i2c_reg_write(u8 addr
, u8 reg
, u8 val
)
814 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
815 __func__
, addr
, reg
, val
);
818 i2c_write(addr
, reg
, 1, &val
, 1);
822 * Functions for setting the current I2C bus and its speed
828 * Change the active I2C bus. Subsequent read/write calls will
831 * bus - bus index, zero based
833 * Returns: 0 on success, not 0 on failure
836 int i2c_set_bus_num(unsigned int bus
);
841 * Returns index of currently active I2C bus. Zero-based.
844 unsigned int i2c_get_bus_num(void);
849 * Change the speed of the active I2C bus
851 * speed - bus speed in Hz
853 * Returns: 0 on success, not 0 on failure
856 int i2c_set_bus_speed(unsigned int);
861 * Returns speed of currently active I2C bus in Hz
864 unsigned int i2c_get_bus_speed(void);
865 #endif /* CONFIG_SYS_I2C */
868 * only for backwardcompatibility, should go away if we switched
869 * completely to new multibus support.
871 #if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)
872 # if !defined(CONFIG_SYS_MAX_I2C_BUS)
873 # define CONFIG_SYS_MAX_I2C_BUS 2
875 # define I2C_MULTI_BUS 1
877 # define CONFIG_SYS_MAX_I2C_BUS 1
878 # define I2C_MULTI_BUS 0
881 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
882 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline
));
883 static inline unsigned int I2C_GET_BUS(void)
885 return I2C_MULTI_BUS
? i2c_get_bus_num() : 0;
888 static inline void I2C_SET_BUS(unsigned int bus
) __attribute__((always_inline
));
889 static inline void I2C_SET_BUS(unsigned int bus
)
892 i2c_set_bus_num(bus
);
895 /* Multi I2C definitions */
897 I2C_0
, I2C_1
, I2C_2
, I2C_3
, I2C_4
, I2C_5
, I2C_6
, I2C_7
,
898 I2C_8
, I2C_9
, I2C_10
,
902 * Get FDT values for i2c bus.
904 * @param blob Device tree blbo
905 * @return the number of I2C bus
907 void board_i2c_init(const void *blob
);
910 * Find the I2C bus number by given a FDT I2C node.
912 * @param blob Device tree blbo
913 * @param node FDT I2C node to find
914 * @return the number of I2C bus (zero based), or -1 on error
916 int i2c_get_bus_num_fdt(int node
);
919 * Reset the I2C bus represented by the given a FDT I2C node.
921 * @param blob Device tree blbo
922 * @param node FDT I2C node to find
923 * @return 0 if port was reset, -1 if not found
925 int i2c_reset_port_fdt(const void *blob
, int node
);
927 #endif /* !CONFIG_DM_I2C */