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.
19 #include <linker_lists.h>
22 * For now there are essentially two parts to this file - driver model
23 * here at the top, and the older code below (with CONFIG_SYS_I2C being
24 * most recent). The plan is to migrate everything to driver model.
25 * The driver model structures and API are separate as they are different
26 * enough as to be incompatible for compilation purposes.
29 enum dm_i2c_chip_flags {
30 DM_I2C_CHIP_10BIT = 1 << 0, /* Use 10-bit addressing */
31 DM_I2C_CHIP_RD_ADDRESS = 1 << 1, /* Send address for each read byte */
32 DM_I2C_CHIP_WR_ADDRESS = 1 << 2, /* Send address for each write byte */
35 /** enum i2c_speed_mode - standard I2C speed modes */
37 IC_SPEED_MODE_STANDARD,
39 IC_SPEED_MODE_FAST_PLUS,
41 IC_SPEED_MODE_FAST_ULTRA,
46 /** enum i2c_speed_rate - standard I2C speeds in Hz */
48 I2C_SPEED_STANDARD_RATE = 100000,
49 I2C_SPEED_FAST_RATE = 400000,
50 I2C_SPEED_FAST_PLUS_RATE = 1000000,
51 I2C_SPEED_HIGH_RATE = 3400000,
52 I2C_SPEED_FAST_ULTRA_RATE = 5000000,
55 /** enum i2c_address_mode - available address modes */
56 enum i2c_address_mode {
63 * struct dm_i2c_chip - information about an i2c chip
65 * An I2C chip is a device on the I2C bus. It sits at a particular address
66 * and normally supports 7-bit or 10-bit addressing.
68 * To obtain this structure, use dev_get_parent_platdata(dev) where dev is
69 * the chip to examine.
71 * @chip_addr: Chip address on bus
72 * @offset_len: Length of offset in bytes. A single byte offset can
73 * represent up to 256 bytes. A value larger than 1 may be
74 * needed for larger devices.
75 * @flags: Flags for this chip (dm_i2c_chip_flags)
76 * @chip_addr_offset_mask: Mask of offset bits within chip_addr. Used for
77 * devices which steal addresses as part of offset.
78 * If offset_len is zero, then the offset is encoded
79 * completely within the chip address itself.
80 * e.g. a devce with chip address of 0x2c with 512
81 * registers might use the bottom bit of the address
82 * to indicate which half of the address space is being
83 * accessed while still only using 1 byte offset.
84 * This means it will respond to chip address 0x2c and
86 * A real world example is the Atmel AT24C04. It's
87 * datasheet explains it's usage of this addressing
89 * @emul: Emulator for this chip address (only used for emulation)
95 uint chip_addr_offset_mask;
103 * struct dm_i2c_bus- information about an i2c bus
105 * An I2C bus contains 0 or more chips on it, each at its own address. The
106 * bus can operate at different speeds (measured in Hz, typically 100KHz
109 * To obtain this structure, use dev_get_uclass_priv(bus) where bus is the
112 * @speed_hz: Bus speed in hertz (typically 100000)
113 * @max_transaction_bytes: Maximal size of single I2C transfer
117 int max_transaction_bytes;
121 * Not all of these flags are implemented in the U-Boot API
123 enum dm_i2c_msg_flags {
124 I2C_M_TEN = 0x0010, /* ten-bit chip address */
125 I2C_M_RD = 0x0001, /* read data, from slave to master */
126 I2C_M_STOP = 0x8000, /* send stop after this message */
127 I2C_M_NOSTART = 0x4000, /* no start before this message */
128 I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */
129 I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */
130 I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */
131 I2C_M_RECV_LEN = 0x0400, /* length is first received byte */
135 * struct i2c_msg - an I2C message
137 * @addr: Slave address
138 * @flags: Flags (see enum dm_i2c_msg_flags)
139 * @len: Length of buffer in bytes, may be 0 for a probe
140 * @buf: Buffer to send/receive, or NULL if no data
150 * struct i2c_msg_list - a list of I2C messages
152 * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
153 * appropriate in U-Boot.
155 * @msg: Pointer to i2c_msg array
156 * @nmsgs: Number of elements in the array
158 struct i2c_msg_list {
159 struct i2c_msg *msgs;
164 * dm_i2c_read() - read bytes from an I2C chip
166 * To obtain an I2C device (called a 'chip') given the I2C bus address you
167 * can use i2c_get_chip(). To obtain a bus by bus number use
168 * uclass_get_device_by_seq(UCLASS_I2C, <bus number>).
170 * To set the address length of a devce use i2c_set_addr_len(). It
173 * @dev: Chip to read from
174 * @offset: Offset within chip to start reading
175 * @buffer: Place to put data
176 * @len: Number of bytes to read
178 * @return 0 on success, -ve on failure
180 int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len);
183 * dm_i2c_write() - write bytes to an I2C chip
185 * See notes for dm_i2c_read() above.
187 * @dev: Chip to write to
188 * @offset: Offset within chip to start writing
189 * @buffer: Buffer containing data to write
190 * @len: Number of bytes to write
192 * @return 0 on success, -ve on failure
194 int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
198 * dm_i2c_probe() - probe a particular chip address
200 * This can be useful to check for the existence of a chip on the bus.
201 * It is typically implemented by writing the chip address to the bus
202 * and checking that the chip replies with an ACK.
205 * @chip_addr: 7-bit address to probe (10-bit and others are not supported)
206 * @chip_flags: Flags for the probe (see enum dm_i2c_chip_flags)
207 * @devp: Returns the device found, or NULL if none
208 * @return 0 if a chip was found at that address, -ve if not
210 int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
211 struct udevice **devp);
214 * dm_i2c_reg_read() - Read a value from an I2C register
216 * This reads a single value from the given address in an I2C chip
218 * @dev: Device to use for transfer
219 * @addr: Address to read from
220 * @return value read, or -ve on error
222 int dm_i2c_reg_read(struct udevice *dev, uint offset);
225 * dm_i2c_reg_write() - Write a value to an I2C register
227 * This writes a single value to the given address in an I2C chip
229 * @dev: Device to use for transfer
230 * @addr: Address to write to
231 * @val: Value to write (normally a byte)
232 * @return 0 on success, -ve on error
234 int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
237 * dm_i2c_xfer() - Transfer messages over I2C
239 * This transfers a raw message. It is best to use dm_i2c_reg_read/write()
242 * @dev: Device to use for transfer
243 * @msg: List of messages to transfer
244 * @nmsgs: Number of messages to transfer
245 * @return 0 on success, -ve on error
247 int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs);
250 * dm_i2c_set_bus_speed() - set the speed of a bus
252 * @bus: Bus to adjust
253 * @speed: Requested speed in Hz
254 * @return 0 if OK, -EINVAL for invalid values
256 int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
259 * dm_i2c_get_bus_speed() - get the speed of a bus
262 * @return speed of selected I2C bus in Hz, -ve on error
264 int dm_i2c_get_bus_speed(struct udevice *bus);
267 * i2c_set_chip_flags() - set flags for a chip
269 * Typically addresses are 7 bits, but for 10-bit addresses you should set
270 * flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
272 * @dev: Chip to adjust
274 * @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
276 int i2c_set_chip_flags(struct udevice *dev, uint flags);
279 * i2c_get_chip_flags() - get flags for a chip
281 * @dev: Chip to check
282 * @flagsp: Place to put flags
283 * @return 0 if OK, other -ve value on error
285 int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
288 * i2c_set_offset_len() - set the offset length for a chip
290 * The offset used to access a chip may be up to 4 bytes long. Typically it
291 * is only 1 byte, which is enough for chips with 256 bytes of memory or
292 * registers. The default value is 1, but you can call this function to
295 * @offset_len: New offset length value (typically 1 or 2)
297 int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
300 * i2c_get_offset_len() - get the offset length for a chip
302 * @return: Current offset length value (typically 1 or 2)
304 int i2c_get_chip_offset_len(struct udevice *dev);
307 * i2c_set_chip_addr_offset_mask() - set mask of address bits usable by offset
309 * Some devices listen on multiple chip addresses to achieve larger offsets
310 * than their single or multiple byte offsets would allow for. You can use this
311 * function to set the bits that are valid to be used for offset overflow.
313 * @mask: The mask to be used for high offset bits within address
314 * @return 0 if OK, other -ve value on error
316 int i2c_set_chip_addr_offset_mask(struct udevice *dev, uint mask);
319 * i2c_get_chip_addr_offset_mask() - get mask of address bits usable by offset
321 * @return current chip addr offset mask
323 uint i2c_get_chip_addr_offset_mask(struct udevice *dev);
326 * i2c_deblock() - recover a bus that is in an unknown state
328 * See the deblock() method in 'struct dm_i2c_ops' for full information
330 * @bus: Bus to recover
331 * @return 0 if OK, -ve on error
333 int i2c_deblock(struct udevice *bus);
336 * i2c_deblock_gpio_loop() - recover a bus from an unknown state by toggling SDA/SCL
338 * This is the inner logic used for toggling I2C SDA/SCL lines as GPIOs
339 * for deblocking the I2C bus.
343 * @scl_count: Number of SCL clock cycles generated to deblock SDA
344 * @start_count:Number of I2C start conditions sent after deblocking SDA
345 * @delay: Delay between SCL clock line changes
346 * @return 0 if OK, -ve on error
349 int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin, struct gpio_desc *scl_pin,
350 unsigned int scl_count, unsigned int start_count,
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);
541 * i2c_emul_find() - Find an emulator for an i2c sandbox device
543 * This looks at the device's 'emul' phandle
545 * @dev: Device to find an emulator for
546 * @emulp: Returns the associated emulator, if found *
547 * @return 0 if OK, -ENOENT or -ENODEV if not found
549 int i2c_emul_find(struct udevice *dev, struct udevice **emulp);
552 * i2c_emul_get_device() - Find the device being emulated
554 * Given an emulator this returns the associated device
556 * @emul: Emulator for the device
557 * @return device that @emul is emulating
559 struct udevice *i2c_emul_get_device(struct udevice *emul);
561 #ifndef CONFIG_DM_I2C
564 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
566 * The implementation MUST NOT use static or global variables if the
567 * I2C routines are used to read SDRAM configuration information
568 * because this is done before the memories are initialized. Limited
569 * use of stack-based variables are OK (the initial stack size is
572 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
576 * Configuration items.
578 #define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
580 #if !defined(CONFIG_SYS_I2C_MAX_HOPS)
581 /* no muxes used bus = i2c adapters */
582 #define CONFIG_SYS_I2C_DIRECT_BUS 1
583 #define CONFIG_SYS_I2C_MAX_HOPS 0
584 #define CONFIG_SYS_NUM_I2C_BUSES ll_entry_count(struct i2c_adapter, i2c)
586 /* we use i2c muxes */
587 #undef CONFIG_SYS_I2C_DIRECT_BUS
590 /* define the I2C bus number for RTC and DTT if not already done */
591 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
592 #define CONFIG_SYS_RTC_BUS_NUM 0
594 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
595 #define CONFIG_SYS_SPD_BUS_NUM 0
599 void (*init)(struct i2c_adapter *adap, int speed,
601 int (*probe)(struct i2c_adapter *adap, uint8_t chip);
602 int (*read)(struct i2c_adapter *adap, uint8_t chip,
603 uint addr, int alen, uint8_t *buffer,
605 int (*write)(struct i2c_adapter *adap, uint8_t chip,
606 uint addr, int alen, uint8_t *buffer,
608 uint (*set_bus_speed)(struct i2c_adapter *adap,
618 #define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
619 _set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
625 .set_bus_speed = _set_speed, \
627 .slaveaddr = _slaveaddr, \
629 .hwadapnr = _hwadapnr, \
633 #define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
634 _set_speed, _speed, _slaveaddr, _hwadapnr) \
635 ll_entry_declare(struct i2c_adapter, _name, i2c) = \
636 U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
637 _set_speed, _speed, _slaveaddr, _hwadapnr, _name);
639 struct i2c_adapter *i2c_get_adapter(int index);
641 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
647 struct i2c_next_hop {
653 struct i2c_bus_hose {
655 struct i2c_next_hop next_hop[CONFIG_SYS_I2C_MAX_HOPS];
657 #define I2C_NULL_HOP {{-1, ""}, 0, 0}
658 extern struct i2c_bus_hose i2c_bus[];
660 #define I2C_ADAPTER(bus) i2c_bus[bus].adapter
662 #define I2C_ADAPTER(bus) bus
664 #define I2C_BUS gd->cur_i2c_bus
666 #define I2C_ADAP_NR(bus) i2c_get_adapter(I2C_ADAPTER(bus))
667 #define I2C_ADAP I2C_ADAP_NR(gd->cur_i2c_bus)
668 #define I2C_ADAP_HWNR (I2C_ADAP->hwadapnr)
670 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
671 #define I2C_MUX_PCA9540_ID 1
672 #define I2C_MUX_PCA9540 {I2C_MUX_PCA9540_ID, "PCA9540B"}
673 #define I2C_MUX_PCA9542_ID 2
674 #define I2C_MUX_PCA9542 {I2C_MUX_PCA9542_ID, "PCA9542A"}
675 #define I2C_MUX_PCA9544_ID 3
676 #define I2C_MUX_PCA9544 {I2C_MUX_PCA9544_ID, "PCA9544A"}
677 #define I2C_MUX_PCA9547_ID 4
678 #define I2C_MUX_PCA9547 {I2C_MUX_PCA9547_ID, "PCA9547A"}
679 #define I2C_MUX_PCA9548_ID 5
680 #define I2C_MUX_PCA9548 {I2C_MUX_PCA9548_ID, "PCA9548"}
683 #ifndef I2C_SOFT_DECLARATIONS
684 # if (defined(CONFIG_AT91RM9200) || \
685 defined(CONFIG_AT91SAM9260) || defined(CONFIG_AT91SAM9261) || \
686 defined(CONFIG_AT91SAM9263))
687 # define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) ATMEL_BASE_PIOA;
689 # define I2C_SOFT_DECLARATIONS
694 * Many boards/controllers/drivers don't support an I2C slave interface so
695 * provide a default slave address for them for use in common code. A real
696 * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
697 * support a slave interface.
699 #ifndef CONFIG_SYS_I2C_SLAVE
700 #define CONFIG_SYS_I2C_SLAVE 0xfe
704 * Initialization, must be called once on start up, may be called
705 * repeatedly to change the speed and slave addresses.
707 #ifdef CONFIG_SYS_I2C_EARLY_INIT
708 void i2c_early_init_f(void);
710 void i2c_init(int speed, int slaveaddr);
711 void i2c_init_board(void);
713 #ifdef CONFIG_SYS_I2C
717 * Returns index of currently active I2C bus. Zero-based.
719 unsigned int i2c_get_bus_num(void);
724 * Change the active I2C bus. Subsequent read/write calls will
727 * bus - bus index, zero based
729 * Returns: 0 on success, not 0 on failure
732 int i2c_set_bus_num(unsigned int bus);
737 * Initializes all I2C adapters in the system. All i2c_adap structures must
738 * be initialized beforehead with function pointers and data, including
739 * speed and slaveaddr. Returns 0 on success, non-0 on failure.
741 void i2c_init_all(void);
744 * Probe the given I2C chip address. Returns 0 if a chip responded,
747 int i2c_probe(uint8_t chip);
750 * Read/Write interface:
751 * chip: I2C chip address, range 0..127
752 * addr: Memory (register) address within the chip
753 * alen: Number of bytes to use for addr (typically 1, 2 for larger
754 * memories, 0 for register type devices with only one
756 * buffer: Where to read/write the data
757 * len: How many bytes to read/write
759 * Returns: 0 on success, not 0 on failure
761 int i2c_read(uint8_t chip, unsigned int addr, int alen,
762 uint8_t *buffer, int len);
764 int i2c_write(uint8_t chip, unsigned int addr, int alen,
765 uint8_t *buffer, int len);
768 * Utility routines to read/write registers.
770 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
772 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
777 * Change the speed of the active I2C bus
779 * speed - bus speed in Hz
781 * Returns: new bus speed
784 unsigned int i2c_set_bus_speed(unsigned int speed);
789 * Returns speed of currently active I2C bus in Hz
792 unsigned int i2c_get_bus_speed(void);
797 * Probe the given I2C chip address. Returns 0 if a chip responded,
800 int i2c_probe(uchar chip);
803 * Read/Write interface:
804 * chip: I2C chip address, range 0..127
805 * addr: Memory (register) address within the chip
806 * alen: Number of bytes to use for addr (typically 1, 2 for larger
807 * memories, 0 for register type devices with only one
809 * buffer: Where to read/write the data
810 * len: How many bytes to read/write
812 * Returns: 0 on success, not 0 on failure
814 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
815 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
818 * Utility routines to read/write registers.
820 static inline u8 i2c_reg_read(u8 addr, u8 reg)
825 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
828 i2c_read(addr, reg, 1, &buf, 1);
833 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
836 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
837 __func__, addr, reg, val);
840 i2c_write(addr, reg, 1, &val, 1);
844 * Functions for setting the current I2C bus and its speed
850 * Change the active I2C bus. Subsequent read/write calls will
853 * bus - bus index, zero based
855 * Returns: 0 on success, not 0 on failure
858 int i2c_set_bus_num(unsigned int bus);
863 * Returns index of currently active I2C bus. Zero-based.
866 unsigned int i2c_get_bus_num(void);
871 * Change the speed of the active I2C bus
873 * speed - bus speed in Hz
875 * Returns: 0 on success, not 0 on failure
878 int i2c_set_bus_speed(unsigned int);
883 * Returns speed of currently active I2C bus in Hz
886 unsigned int i2c_get_bus_speed(void);
887 #endif /* CONFIG_SYS_I2C */
890 * only for backwardcompatibility, should go away if we switched
891 * completely to new multibus support.
893 #if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)
894 # if !defined(CONFIG_SYS_MAX_I2C_BUS)
895 # define CONFIG_SYS_MAX_I2C_BUS 2
897 # define I2C_MULTI_BUS 1
899 # define CONFIG_SYS_MAX_I2C_BUS 1
900 # define I2C_MULTI_BUS 0
903 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
904 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
905 static inline unsigned int I2C_GET_BUS(void)
907 return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
910 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
911 static inline void I2C_SET_BUS(unsigned int bus)
914 i2c_set_bus_num(bus);
917 /* Multi I2C definitions */
919 I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
920 I2C_8, I2C_9, I2C_10,
924 * Get FDT values for i2c bus.
926 * @param blob Device tree blbo
927 * @return the number of I2C bus
929 void board_i2c_init(const void *blob);
932 * Find the I2C bus number by given a FDT I2C node.
934 * @param blob Device tree blbo
935 * @param node FDT I2C node to find
936 * @return the number of I2C bus (zero based), or -1 on error
938 int i2c_get_bus_num_fdt(int node);
941 * Reset the I2C bus represented by the given a FDT I2C node.
943 * @param blob Device tree blbo
944 * @param node FDT I2C node to find
945 * @return 0 if port was reset, -1 if not found
947 int i2c_reset_port_fdt(const void *blob, int node);
949 #endif /* !CONFIG_DM_I2C */