2 * Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
3 * Copyright (C) 2009 - 2013 Heiko Schocher <hs@denx.de>
4 * Changes for multibus/multiadapter I2C support.
7 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
9 * SPDX-License-Identifier: GPL-2.0+
11 * The original I2C interface was
12 * (C) 2000 by Paolo Scaffardi (arsenio@tin.it)
13 * AIRVENT SAM s.p.a - RIMINI(ITALY)
14 * but has been changed substantially.
21 * For now there are essentially two parts to this file - driver model
22 * here at the top, and the older code below (with CONFIG_SYS_I2C being
23 * most recent). The plan is to migrate everything to driver model.
24 * The driver model structures and API are separate as they are different
25 * enough as to be incompatible for compilation purposes.
28 enum dm_i2c_chip_flags {
29 DM_I2C_CHIP_10BIT = 1 << 0, /* Use 10-bit addressing */
30 DM_I2C_CHIP_RD_ADDRESS = 1 << 1, /* Send address for each read byte */
31 DM_I2C_CHIP_WR_ADDRESS = 1 << 2, /* Send address for each write byte */
36 * struct dm_i2c_chip - information about an i2c chip
38 * An I2C chip is a device on the I2C bus. It sits at a particular address
39 * and normally supports 7-bit or 10-bit addressing.
41 * To obtain this structure, use dev_get_parent_platdata(dev) where dev is
42 * the chip to examine.
44 * @chip_addr: Chip address on bus
45 * @offset_len: Length of offset in bytes. A single byte offset can
46 * represent up to 256 bytes. A value larger than 1 may be
47 * needed for larger devices.
48 * @flags: Flags for this chip (dm_i2c_chip_flags)
49 * @emul: Emulator for this chip address (only used for emulation)
62 * struct dm_i2c_bus- information about an i2c bus
64 * An I2C bus contains 0 or more chips on it, each at its own address. The
65 * bus can operate at different speeds (measured in Hz, typically 100KHz
68 * To obtain this structure, use dev_get_uclass_priv(bus) where bus is the
71 * @speed_hz: Bus speed in hertz (typically 100000)
78 * Not all of these flags are implemented in the U-Boot API
80 enum dm_i2c_msg_flags {
81 I2C_M_TEN = 0x0010, /* ten-bit chip address */
82 I2C_M_RD = 0x0001, /* read data, from slave to master */
83 I2C_M_STOP = 0x8000, /* send stop after this message */
84 I2C_M_NOSTART = 0x4000, /* no start before this message */
85 I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */
86 I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */
87 I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */
88 I2C_M_RECV_LEN = 0x0400, /* length is first received byte */
92 * struct i2c_msg - an I2C message
94 * @addr: Slave address
95 * @flags: Flags (see enum dm_i2c_msg_flags)
96 * @len: Length of buffer in bytes, may be 0 for a probe
97 * @buf: Buffer to send/receive, or NULL if no data
107 * struct i2c_msg_list - a list of I2C messages
109 * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
110 * appropriate in U-Boot.
112 * @msg: Pointer to i2c_msg array
113 * @nmsgs: Number of elements in the array
115 struct i2c_msg_list {
116 struct i2c_msg *msgs;
121 * dm_i2c_read() - read bytes from an I2C chip
123 * To obtain an I2C device (called a 'chip') given the I2C bus address you
124 * can use i2c_get_chip(). To obtain a bus by bus number use
125 * uclass_get_device_by_seq(UCLASS_I2C, <bus number>).
127 * To set the address length of a devce use i2c_set_addr_len(). It
130 * @dev: Chip to read from
131 * @offset: Offset within chip to start reading
132 * @buffer: Place to put data
133 * @len: Number of bytes to read
135 * @return 0 on success, -ve on failure
137 int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len);
140 * dm_i2c_write() - write bytes to an I2C chip
142 * See notes for dm_i2c_read() above.
144 * @dev: Chip to write to
145 * @offset: Offset within chip to start writing
146 * @buffer: Buffer containing data to write
147 * @len: Number of bytes to write
149 * @return 0 on success, -ve on failure
151 int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
155 * dm_i2c_probe() - probe a particular chip address
157 * This can be useful to check for the existence of a chip on the bus.
158 * It is typically implemented by writing the chip address to the bus
159 * and checking that the chip replies with an ACK.
162 * @chip_addr: 7-bit address to probe (10-bit and others are not supported)
163 * @chip_flags: Flags for the probe (see enum dm_i2c_chip_flags)
164 * @devp: Returns the device found, or NULL if none
165 * @return 0 if a chip was found at that address, -ve if not
167 int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
168 struct udevice **devp);
171 * dm_i2c_reg_read() - Read a value from an I2C register
173 * This reads a single value from the given address in an I2C chip
175 * @dev: Device to use for transfer
176 * @addr: Address to read from
177 * @return value read, or -ve on error
179 int dm_i2c_reg_read(struct udevice *dev, uint offset);
182 * dm_i2c_reg_write() - Write a value to an I2C register
184 * This writes a single value to the given address in an I2C chip
186 * @dev: Device to use for transfer
187 * @addr: Address to write to
188 * @val: Value to write (normally a byte)
189 * @return 0 on success, -ve on error
191 int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
194 * dm_i2c_xfer() - Transfer messages over I2C
196 * This transfers a raw message. It is best to use dm_i2c_reg_read/write()
199 * @dev: Device to use for transfer
200 * @msg: List of messages to transfer
201 * @nmsgs: Number of messages to transfer
202 * @return 0 on success, -ve on error
204 int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs);
207 * dm_i2c_set_bus_speed() - set the speed of a bus
209 * @bus: Bus to adjust
210 * @speed: Requested speed in Hz
211 * @return 0 if OK, -EINVAL for invalid values
213 int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
216 * dm_i2c_get_bus_speed() - get the speed of a bus
219 * @return speed of selected I2C bus in Hz, -ve on error
221 int dm_i2c_get_bus_speed(struct udevice *bus);
224 * i2c_set_chip_flags() - set flags for a chip
226 * Typically addresses are 7 bits, but for 10-bit addresses you should set
227 * flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
229 * @dev: Chip to adjust
231 * @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
233 int i2c_set_chip_flags(struct udevice *dev, uint flags);
236 * i2c_get_chip_flags() - get flags for a chip
238 * @dev: Chip to check
239 * @flagsp: Place to put flags
240 * @return 0 if OK, other -ve value on error
242 int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
245 * i2c_set_offset_len() - set the offset length for a chip
247 * The offset used to access a chip may be up to 4 bytes long. Typically it
248 * is only 1 byte, which is enough for chips with 256 bytes of memory or
249 * registers. The default value is 1, but you can call this function to
252 * @offset_len: New offset length value (typically 1 or 2)
254 int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
257 * i2c_get_offset_len() - get the offset length for a chip
259 * @return: Current offset length value (typically 1 or 2)
261 int i2c_get_chip_offset_len(struct udevice *dev);
264 * i2c_deblock() - recover a bus that is in an unknown state
266 * See the deblock() method in 'struct dm_i2c_ops' for full information
268 * @bus: Bus to recover
269 * @return 0 if OK, -ve on error
271 int i2c_deblock(struct udevice *bus);
273 #ifdef CONFIG_DM_I2C_COMPAT
275 * i2c_probe() - Compatibility function for driver model
277 * Calls dm_i2c_probe() on the current bus
279 int i2c_probe(uint8_t chip_addr);
282 * i2c_read() - Compatibility function for driver model
284 * Calls dm_i2c_read() with the device corresponding to @chip_addr, and offset
285 * set to @addr. @alen must match the current setting for the device.
287 int i2c_read(uint8_t chip_addr, unsigned int addr, int alen, uint8_t *buffer,
291 * i2c_write() - Compatibility function for driver model
293 * Calls dm_i2c_write() with the device corresponding to @chip_addr, and offset
294 * set to @addr. @alen must match the current setting for the device.
296 int i2c_write(uint8_t chip_addr, unsigned int addr, int alen, uint8_t *buffer,
300 * i2c_get_bus_num_fdt() - Compatibility function for driver model
302 * @return the bus number associated with the given device tree node
304 int i2c_get_bus_num_fdt(int node);
307 * i2c_get_bus_num() - Compatibility function for driver model
309 * @return the 'current' bus number
311 unsigned int i2c_get_bus_num(void);
314 * i2c_set_bus_num() - Compatibility function for driver model
316 * Sets the 'current' bus
318 int i2c_set_bus_num(unsigned int bus);
320 static inline void I2C_SET_BUS(unsigned int bus)
322 i2c_set_bus_num(bus);
325 static inline unsigned int I2C_GET_BUS(void)
327 return i2c_get_bus_num();
331 * i2c_init() - Compatibility function for driver model
333 * This function does nothing.
335 void i2c_init(int speed, int slaveaddr);
338 * board_i2c_init() - Compatibility function for driver model
340 * @param blob Device tree blbo
341 * @return the number of I2C bus
343 void board_i2c_init(const void *blob);
346 * Compatibility functions for driver model.
348 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
349 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
354 * struct dm_i2c_ops - driver operations for I2C uclass
356 * Drivers should support these operations unless otherwise noted. These
357 * operations are intended to be used by uclass code, not directly from
362 * xfer() - transfer a list of I2C messages
364 * @bus: Bus to read from
365 * @msg: List of messages to transfer
366 * @nmsgs: Number of messages in the list
367 * @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
368 * -ECOMM if the speed cannot be supported, -EPROTO if the chip
369 * flags cannot be supported, other -ve value on some other error
371 int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
374 * probe_chip() - probe for the presense of a chip address
376 * This function is optional. If omitted, the uclass will send a zero
377 * length message instead.
380 * @chip_addr: Chip address to probe
381 * @chip_flags: Probe flags (enum dm_i2c_chip_flags)
382 * @return 0 if chip was found, -EREMOTEIO if not, -ENOSYS to fall back
383 * to default probem other -ve value on error
385 int (*probe_chip)(struct udevice *bus, uint chip_addr, uint chip_flags);
388 * set_bus_speed() - set the speed of a bus (optional)
390 * The bus speed value will be updated by the uclass if this function
391 * does not return an error. This method is optional - if it is not
392 * provided then the driver can read the speed from
393 * dev_get_uclass_priv(bus)->speed_hz
395 * @bus: Bus to adjust
396 * @speed: Requested speed in Hz
397 * @return 0 if OK, -EINVAL for invalid values
399 int (*set_bus_speed)(struct udevice *bus, unsigned int speed);
402 * get_bus_speed() - get the speed of a bus (optional)
404 * Normally this can be provided by the uclass, but if you want your
405 * driver to check the bus speed by looking at the hardware, you can
406 * implement that here. This method is optional. This method would
407 * normally be expected to return dev_get_uclass_priv(bus)->speed_hz.
410 * @return speed of selected I2C bus in Hz, -ve on error
412 int (*get_bus_speed)(struct udevice *bus);
415 * set_flags() - set the flags for a chip (optional)
417 * This is generally implemented by the uclass, but drivers can
418 * check the value to ensure that unsupported options are not used.
419 * This method is optional. If provided, this method will always be
420 * called when the flags change.
422 * @dev: Chip to adjust
423 * @flags: New flags value
424 * @return 0 if OK, -EINVAL if value is unsupported
426 int (*set_flags)(struct udevice *dev, uint flags);
429 * deblock() - recover a bus that is in an unknown state
431 * I2C is a synchronous protocol and resets of the processor in the
432 * middle of an access can block the I2C Bus until a powerdown of
433 * the full unit is done. This is because slaves can be stuck
434 * waiting for addition bus transitions for a transaction that will
435 * never complete. Resetting the I2C master does not help. The only
436 * way is to force the bus through a series of transitions to make
437 * sure that all slaves are done with the transaction. This method
438 * performs this 'deblocking' if support by the driver.
440 * This method is optional.
442 int (*deblock)(struct udevice *bus);
445 #define i2c_get_ops(dev) ((struct dm_i2c_ops *)(dev)->driver->ops)
448 * struct i2c_mux_ops - operations for an I2C mux
450 * The current mux state is expected to be stored in the mux itself since
451 * it is the only thing that knows how to make things work. The mux can
452 * record the current state and then avoid switching unless it is necessary.
453 * So select() can be skipped if the mux is already in the correct state.
454 * Also deselect() can be made a nop if required.
458 * select() - select one of of I2C buses attached to a mux
460 * This will be called when there is no bus currently selected by the
461 * mux. This method does not need to deselect the old bus since
462 * deselect() will be already have been called if necessary.
465 * @bus: I2C bus to select
466 * @channel: Channel number correponding to the bus to select
467 * @return 0 if OK, -ve on error
469 int (*select)(struct udevice *mux, struct udevice *bus, uint channel);
472 * deselect() - select one of of I2C buses attached to a mux
474 * This is used to deselect the currently selected I2C bus.
477 * @bus: I2C bus to deselect
478 * @channel: Channel number correponding to the bus to deselect
479 * @return 0 if OK, -ve on error
481 int (*deselect)(struct udevice *mux, struct udevice *bus, uint channel);
484 #define i2c_mux_get_ops(dev) ((struct i2c_mux_ops *)(dev)->driver->ops)
487 * i2c_get_chip() - get a device to use to access a chip on a bus
489 * This returns the device for the given chip address. The device can then
490 * be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc.
492 * @bus: Bus to examine
493 * @chip_addr: Chip address for the new device
494 * @offset_len: Length of a register offset in bytes (normally 1)
495 * @devp: Returns pointer to new device if found or -ENODEV if not
498 int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
499 struct udevice **devp);
502 * i2c_get_chip_for_busnum() - get a device to use to access a chip on
505 * This returns the device for the given chip address on a particular bus
508 * @busnum: Bus number to examine
509 * @chip_addr: Chip address for the new device
510 * @offset_len: Length of a register offset in bytes (normally 1)
511 * @devp: Returns pointer to new device if found or -ENODEV if not
514 int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
515 struct udevice **devp);
518 * i2c_chip_ofdata_to_platdata() - Decode standard I2C platform data
520 * This decodes the chip address from a device tree node and puts it into
521 * its dm_i2c_chip structure. This should be called in your driver's
522 * ofdata_to_platdata() method.
524 * @blob: Device tree blob
525 * @node: Node offset to read from
526 * @spi: Place to put the decoded information
528 int i2c_chip_ofdata_to_platdata(struct udevice *dev, struct dm_i2c_chip *chip);
531 * i2c_dump_msgs() - Dump a list of I2C messages
533 * This may be useful for debugging.
535 * @msg: Message list to dump
536 * @nmsgs: Number of messages
538 void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs);
540 #ifndef CONFIG_DM_I2C
543 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
545 * The implementation MUST NOT use static or global variables if the
546 * I2C routines are used to read SDRAM configuration information
547 * because this is done before the memories are initialized. Limited
548 * use of stack-based variables are OK (the initial stack size is
551 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
555 * Configuration items.
557 #define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
559 #if !defined(CONFIG_SYS_I2C_MAX_HOPS)
560 /* no muxes used bus = i2c adapters */
561 #define CONFIG_SYS_I2C_DIRECT_BUS 1
562 #define CONFIG_SYS_I2C_MAX_HOPS 0
563 #define CONFIG_SYS_NUM_I2C_BUSES ll_entry_count(struct i2c_adapter, i2c)
565 /* we use i2c muxes */
566 #undef CONFIG_SYS_I2C_DIRECT_BUS
569 /* define the I2C bus number for RTC and DTT if not already done */
570 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
571 #define CONFIG_SYS_RTC_BUS_NUM 0
573 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
574 #define CONFIG_SYS_SPD_BUS_NUM 0
578 void (*init)(struct i2c_adapter *adap, int speed,
580 int (*probe)(struct i2c_adapter *adap, uint8_t chip);
581 int (*read)(struct i2c_adapter *adap, uint8_t chip,
582 uint addr, int alen, uint8_t *buffer,
584 int (*write)(struct i2c_adapter *adap, uint8_t chip,
585 uint addr, int alen, uint8_t *buffer,
587 uint (*set_bus_speed)(struct i2c_adapter *adap,
597 #define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
598 _set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
604 .set_bus_speed = _set_speed, \
606 .slaveaddr = _slaveaddr, \
608 .hwadapnr = _hwadapnr, \
612 #define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
613 _set_speed, _speed, _slaveaddr, _hwadapnr) \
614 ll_entry_declare(struct i2c_adapter, _name, i2c) = \
615 U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
616 _set_speed, _speed, _slaveaddr, _hwadapnr, _name);
618 struct i2c_adapter *i2c_get_adapter(int index);
620 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
626 struct i2c_next_hop {
632 struct i2c_bus_hose {
634 struct i2c_next_hop next_hop[CONFIG_SYS_I2C_MAX_HOPS];
636 #define I2C_NULL_HOP {{-1, ""}, 0, 0}
637 extern struct i2c_bus_hose i2c_bus[];
639 #define I2C_ADAPTER(bus) i2c_bus[bus].adapter
641 #define I2C_ADAPTER(bus) bus
643 #define I2C_BUS gd->cur_i2c_bus
645 #define I2C_ADAP_NR(bus) i2c_get_adapter(I2C_ADAPTER(bus))
646 #define I2C_ADAP I2C_ADAP_NR(gd->cur_i2c_bus)
647 #define I2C_ADAP_HWNR (I2C_ADAP->hwadapnr)
649 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
650 #define I2C_MUX_PCA9540_ID 1
651 #define I2C_MUX_PCA9540 {I2C_MUX_PCA9540_ID, "PCA9540B"}
652 #define I2C_MUX_PCA9542_ID 2
653 #define I2C_MUX_PCA9542 {I2C_MUX_PCA9542_ID, "PCA9542A"}
654 #define I2C_MUX_PCA9544_ID 3
655 #define I2C_MUX_PCA9544 {I2C_MUX_PCA9544_ID, "PCA9544A"}
656 #define I2C_MUX_PCA9547_ID 4
657 #define I2C_MUX_PCA9547 {I2C_MUX_PCA9547_ID, "PCA9547A"}
658 #define I2C_MUX_PCA9548_ID 5
659 #define I2C_MUX_PCA9548 {I2C_MUX_PCA9548_ID, "PCA9548"}
662 #ifndef I2C_SOFT_DECLARATIONS
663 # if (defined(CONFIG_AT91RM9200) || \
664 defined(CONFIG_AT91SAM9260) || defined(CONFIG_AT91SAM9261) || \
665 defined(CONFIG_AT91SAM9263))
666 # define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) ATMEL_BASE_PIOA;
668 # define I2C_SOFT_DECLARATIONS
673 * Many boards/controllers/drivers don't support an I2C slave interface so
674 * provide a default slave address for them for use in common code. A real
675 * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
676 * support a slave interface.
678 #ifndef CONFIG_SYS_I2C_SLAVE
679 #define CONFIG_SYS_I2C_SLAVE 0xfe
683 * Initialization, must be called once on start up, may be called
684 * repeatedly to change the speed and slave addresses.
686 #ifdef CONFIG_SYS_I2C_EARLY_INIT
687 void i2c_early_init_f(void);
689 void i2c_init(int speed, int slaveaddr);
690 void i2c_init_board(void);
692 #ifdef CONFIG_SYS_I2C
696 * Returns index of currently active I2C bus. Zero-based.
698 unsigned int i2c_get_bus_num(void);
703 * Change the active I2C bus. Subsequent read/write calls will
706 * bus - bus index, zero based
708 * Returns: 0 on success, not 0 on failure
711 int i2c_set_bus_num(unsigned int bus);
716 * Initializes all I2C adapters in the system. All i2c_adap structures must
717 * be initialized beforehead with function pointers and data, including
718 * speed and slaveaddr. Returns 0 on success, non-0 on failure.
720 void i2c_init_all(void);
723 * Probe the given I2C chip address. Returns 0 if a chip responded,
726 int i2c_probe(uint8_t chip);
729 * Read/Write interface:
730 * chip: I2C chip address, range 0..127
731 * addr: Memory (register) address within the chip
732 * alen: Number of bytes to use for addr (typically 1, 2 for larger
733 * memories, 0 for register type devices with only one
735 * buffer: Where to read/write the data
736 * len: How many bytes to read/write
738 * Returns: 0 on success, not 0 on failure
740 int i2c_read(uint8_t chip, unsigned int addr, int alen,
741 uint8_t *buffer, int len);
743 int i2c_write(uint8_t chip, unsigned int addr, int alen,
744 uint8_t *buffer, int len);
747 * Utility routines to read/write registers.
749 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
751 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
756 * Change the speed of the active I2C bus
758 * speed - bus speed in Hz
760 * Returns: new bus speed
763 unsigned int i2c_set_bus_speed(unsigned int speed);
768 * Returns speed of currently active I2C bus in Hz
771 unsigned int i2c_get_bus_speed(void);
776 * Probe the given I2C chip address. Returns 0 if a chip responded,
779 int i2c_probe(uchar chip);
782 * Read/Write interface:
783 * chip: I2C chip address, range 0..127
784 * addr: Memory (register) address within the chip
785 * alen: Number of bytes to use for addr (typically 1, 2 for larger
786 * memories, 0 for register type devices with only one
788 * buffer: Where to read/write the data
789 * len: How many bytes to read/write
791 * Returns: 0 on success, not 0 on failure
793 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
794 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
797 * Utility routines to read/write registers.
799 static inline u8 i2c_reg_read(u8 addr, u8 reg)
804 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
807 i2c_read(addr, reg, 1, &buf, 1);
812 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
815 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
816 __func__, addr, reg, val);
819 i2c_write(addr, reg, 1, &val, 1);
823 * Functions for setting the current I2C bus and its speed
829 * Change the active I2C bus. Subsequent read/write calls will
832 * bus - bus index, zero based
834 * Returns: 0 on success, not 0 on failure
837 int i2c_set_bus_num(unsigned int bus);
842 * Returns index of currently active I2C bus. Zero-based.
845 unsigned int i2c_get_bus_num(void);
850 * Change the speed of the active I2C bus
852 * speed - bus speed in Hz
854 * Returns: 0 on success, not 0 on failure
857 int i2c_set_bus_speed(unsigned int);
862 * Returns speed of currently active I2C bus in Hz
865 unsigned int i2c_get_bus_speed(void);
866 #endif /* CONFIG_SYS_I2C */
869 * only for backwardcompatibility, should go away if we switched
870 * completely to new multibus support.
872 #if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)
873 # if !defined(CONFIG_SYS_MAX_I2C_BUS)
874 # define CONFIG_SYS_MAX_I2C_BUS 2
876 # define I2C_MULTI_BUS 1
878 # define CONFIG_SYS_MAX_I2C_BUS 1
879 # define I2C_MULTI_BUS 0
882 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
883 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
884 static inline unsigned int I2C_GET_BUS(void)
886 return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
889 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
890 static inline void I2C_SET_BUS(unsigned int bus)
893 i2c_set_bus_num(bus);
896 /* Multi I2C definitions */
898 I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
899 I2C_8, I2C_9, I2C_10,
903 * Get FDT values for i2c bus.
905 * @param blob Device tree blbo
906 * @return the number of I2C bus
908 void board_i2c_init(const void *blob);
911 * Find the I2C bus number by given a FDT I2C node.
913 * @param blob Device tree blbo
914 * @param node FDT I2C node to find
915 * @return the number of I2C bus (zero based), or -1 on error
917 int i2c_get_bus_num_fdt(int node);
920 * Reset the I2C bus represented by the given a FDT I2C node.
922 * @param blob Device tree blbo
923 * @param node FDT I2C node to find
924 * @return 0 if port was reset, -1 if not found
926 int i2c_reset_port_fdt(const void *blob, int node);
928 #endif /* !CONFIG_DM_I2C */