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_LEGACY 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 {
61 /** enum i2c_device_t - Types of I2C devices, used for compatible strings */
64 I2C_DEVICE_HID_OVER_I2C,
69 * struct dm_i2c_chip - information about an i2c chip
71 * An I2C chip is a device on the I2C bus. It sits at a particular address
72 * and normally supports 7-bit or 10-bit addressing.
74 * To obtain this structure, use dev_get_parent_plat(dev) where dev is
75 * the chip to examine.
77 * @chip_addr: Chip address on bus
78 * @offset_len: Length of offset in bytes. A single byte offset can
79 * represent up to 256 bytes. A value larger than 1 may be
80 * needed for larger devices.
81 * @flags: Flags for this chip (dm_i2c_chip_flags)
82 * @chip_addr_offset_mask: Mask of offset bits within chip_addr. Used for
83 * devices which steal addresses as part of offset.
84 * If offset_len is zero, then the offset is encoded
85 * completely within the chip address itself.
86 * e.g. a devce with chip address of 0x2c with 512
87 * registers might use the bottom bit of the address
88 * to indicate which half of the address space is being
89 * accessed while still only using 1 byte offset.
90 * This means it will respond to chip address 0x2c and
92 * A real world example is the Atmel AT24C04. It's
93 * datasheet explains it's usage of this addressing
95 * @emul: Emulator for this chip address (only used for emulation)
96 * @emul_idx: Emulator index, used for of-platdata and set by each i2c chip's
97 * bind() method. This allows i2c_emul_find() to work with of-platdata.
103 uint chip_addr_offset_mask;
104 #ifdef CONFIG_SANDBOX
105 struct udevice *emul;
112 * struct dm_i2c_bus- information about an i2c bus
114 * An I2C bus contains 0 or more chips on it, each at its own address. The
115 * bus can operate at different speeds (measured in Hz, typically 100KHz
118 * To obtain this structure, use dev_get_uclass_priv(bus) where bus is the
121 * @speed_hz: Bus speed in hertz (typically 100000)
122 * @max_transaction_bytes: Maximal size of single I2C transfer
126 int max_transaction_bytes;
130 * Not all of these flags are implemented in the U-Boot API
132 enum dm_i2c_msg_flags {
133 I2C_M_TEN = 0x0010, /* ten-bit chip address */
134 I2C_M_RD = 0x0001, /* read data, from slave to master */
135 I2C_M_STOP = 0x8000, /* send stop after this message */
136 I2C_M_NOSTART = 0x4000, /* no start before this message */
137 I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */
138 I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */
139 I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */
140 I2C_M_RECV_LEN = 0x0400, /* length is first received byte */
144 * struct i2c_msg - an I2C message
146 * @addr: Slave address
147 * @flags: Flags (see enum dm_i2c_msg_flags)
148 * @len: Length of buffer in bytes, may be 0 for a probe
149 * @buf: Buffer to send/receive, or NULL if no data
159 * struct i2c_msg_list - a list of I2C messages
161 * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
162 * appropriate in U-Boot.
164 * @msg: Pointer to i2c_msg array
165 * @nmsgs: Number of elements in the array
167 struct i2c_msg_list {
168 struct i2c_msg *msgs;
173 * dm_i2c_read() - read bytes from an I2C chip
175 * To obtain an I2C device (called a 'chip') given the I2C bus address you
176 * can use i2c_get_chip(). To obtain a bus by bus number use
177 * uclass_get_device_by_seq(UCLASS_I2C, <bus number>).
179 * To set the address length of a devce use i2c_set_addr_len(). It
182 * @dev: Chip to read from
183 * @offset: Offset within chip to start reading
184 * @buffer: Place to put data
185 * @len: Number of bytes to read
187 * @return 0 on success, -ve on failure
189 int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len);
192 * dm_i2c_write() - write bytes to an I2C chip
194 * See notes for dm_i2c_read() above.
196 * @dev: Chip to write to
197 * @offset: Offset within chip to start writing
198 * @buffer: Buffer containing data to write
199 * @len: Number of bytes to write
201 * @return 0 on success, -ve on failure
203 int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
207 * dm_i2c_probe() - probe a particular chip address
209 * This can be useful to check for the existence of a chip on the bus.
210 * It is typically implemented by writing the chip address to the bus
211 * and checking that the chip replies with an ACK.
214 * @chip_addr: 7-bit address to probe (10-bit and others are not supported)
215 * @chip_flags: Flags for the probe (see enum dm_i2c_chip_flags)
216 * @devp: Returns the device found, or NULL if none
217 * @return 0 if a chip was found at that address, -ve if not
219 int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
220 struct udevice **devp);
223 * dm_i2c_reg_read() - Read a value from an I2C register
225 * This reads a single value from the given address in an I2C chip
227 * @dev: Device to use for transfer
228 * @addr: Address to read from
229 * @return value read, or -ve on error
231 int dm_i2c_reg_read(struct udevice *dev, uint offset);
234 * dm_i2c_reg_write() - Write a value to an I2C register
236 * This writes a single value to the given address in an I2C chip
238 * @dev: Device to use for transfer
239 * @addr: Address to write to
240 * @val: Value to write (normally a byte)
241 * @return 0 on success, -ve on error
243 int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
246 * dm_i2c_reg_clrset() - Apply bitmask to an I2C register
248 * Read value, apply bitmask and write modified value back to the
249 * given address in an I2C chip
251 * @dev: Device to use for transfer
252 * @offset: Address for the R/W operation
253 * @clr: Bitmask of bits that should be cleared
254 * @set: Bitmask of bits that should be set
255 * @return 0 on success, -ve on error
257 int dm_i2c_reg_clrset(struct udevice *dev, uint offset, u32 clr, u32 set);
260 * dm_i2c_xfer() - Transfer messages over I2C
262 * This transfers a raw message. It is best to use dm_i2c_reg_read/write()
265 * @dev: Device to use for transfer
266 * @msg: List of messages to transfer
267 * @nmsgs: Number of messages to transfer
268 * @return 0 on success, -ve on error
270 int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs);
273 * dm_i2c_set_bus_speed() - set the speed of a bus
275 * @bus: Bus to adjust
276 * @speed: Requested speed in Hz
277 * @return 0 if OK, -EINVAL for invalid values
279 int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
282 * dm_i2c_get_bus_speed() - get the speed of a bus
285 * @return speed of selected I2C bus in Hz, -ve on error
287 int dm_i2c_get_bus_speed(struct udevice *bus);
290 * i2c_set_chip_flags() - set flags for a chip
292 * Typically addresses are 7 bits, but for 10-bit addresses you should set
293 * flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
295 * @dev: Chip to adjust
297 * @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
299 int i2c_set_chip_flags(struct udevice *dev, uint flags);
302 * i2c_get_chip_flags() - get flags for a chip
304 * @dev: Chip to check
305 * @flagsp: Place to put flags
306 * @return 0 if OK, other -ve value on error
308 int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
311 * i2c_set_offset_len() - set the offset length for a chip
313 * The offset used to access a chip may be up to 4 bytes long. Typically it
314 * is only 1 byte, which is enough for chips with 256 bytes of memory or
315 * registers. The default value is 1, but you can call this function to
318 * @offset_len: New offset length value (typically 1 or 2)
320 int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
323 * i2c_get_offset_len() - get the offset length for a chip
325 * @return: Current offset length value (typically 1 or 2)
327 int i2c_get_chip_offset_len(struct udevice *dev);
330 * i2c_set_chip_addr_offset_mask() - set mask of address bits usable by offset
332 * Some devices listen on multiple chip addresses to achieve larger offsets
333 * than their single or multiple byte offsets would allow for. You can use this
334 * function to set the bits that are valid to be used for offset overflow.
336 * @mask: The mask to be used for high offset bits within address
337 * @return 0 if OK, other -ve value on error
339 int i2c_set_chip_addr_offset_mask(struct udevice *dev, uint mask);
342 * i2c_get_chip_addr_offset_mask() - get mask of address bits usable by offset
344 * @return current chip addr offset mask
346 uint i2c_get_chip_addr_offset_mask(struct udevice *dev);
349 * i2c_deblock() - recover a bus that is in an unknown state
351 * See the deblock() method in 'struct dm_i2c_ops' for full information
353 * @bus: Bus to recover
354 * @return 0 if OK, -ve on error
356 int i2c_deblock(struct udevice *bus);
359 * i2c_deblock_gpio_loop() - recover a bus from an unknown state by toggling SDA/SCL
361 * This is the inner logic used for toggling I2C SDA/SCL lines as GPIOs
362 * for deblocking the I2C bus.
366 * @scl_count: Number of SCL clock cycles generated to deblock SDA
367 * @start_count:Number of I2C start conditions sent after deblocking SDA
368 * @delay: Delay between SCL clock line changes
369 * @return 0 if OK, -ve on error
372 int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin, struct gpio_desc *scl_pin,
373 unsigned int scl_count, unsigned int start_count,
377 * struct dm_i2c_ops - driver operations for I2C uclass
379 * Drivers should support these operations unless otherwise noted. These
380 * operations are intended to be used by uclass code, not directly from
385 * xfer() - transfer a list of I2C messages
387 * @bus: Bus to read from
388 * @msg: List of messages to transfer
389 * @nmsgs: Number of messages in the list
390 * @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
391 * -ECOMM if the speed cannot be supported, -EPROTO if the chip
392 * flags cannot be supported, other -ve value on some other error
394 int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
397 * probe_chip() - probe for the presense of a chip address
399 * This function is optional. If omitted, the uclass will send a zero
400 * length message instead.
403 * @chip_addr: Chip address to probe
404 * @chip_flags: Probe flags (enum dm_i2c_chip_flags)
405 * @return 0 if chip was found, -EREMOTEIO if not, -ENOSYS to fall back
406 * to default probem other -ve value on error
408 int (*probe_chip)(struct udevice *bus, uint chip_addr, uint chip_flags);
411 * set_bus_speed() - set the speed of a bus (optional)
413 * The bus speed value will be updated by the uclass if this function
414 * does not return an error. This method is optional - if it is not
415 * provided then the driver can read the speed from
416 * dev_get_uclass_priv(bus)->speed_hz
418 * @bus: Bus to adjust
419 * @speed: Requested speed in Hz
420 * @return 0 if OK, -EINVAL for invalid values
422 int (*set_bus_speed)(struct udevice *bus, unsigned int speed);
425 * get_bus_speed() - get the speed of a bus (optional)
427 * Normally this can be provided by the uclass, but if you want your
428 * driver to check the bus speed by looking at the hardware, you can
429 * implement that here. This method is optional. This method would
430 * normally be expected to return dev_get_uclass_priv(bus)->speed_hz.
433 * @return speed of selected I2C bus in Hz, -ve on error
435 int (*get_bus_speed)(struct udevice *bus);
438 * set_flags() - set the flags for a chip (optional)
440 * This is generally implemented by the uclass, but drivers can
441 * check the value to ensure that unsupported options are not used.
442 * This method is optional. If provided, this method will always be
443 * called when the flags change.
445 * @dev: Chip to adjust
446 * @flags: New flags value
447 * @return 0 if OK, -EINVAL if value is unsupported
449 int (*set_flags)(struct udevice *dev, uint flags);
452 * deblock() - recover a bus that is in an unknown state
454 * I2C is a synchronous protocol and resets of the processor in the
455 * middle of an access can block the I2C Bus until a powerdown of
456 * the full unit is done. This is because slaves can be stuck
457 * waiting for addition bus transitions for a transaction that will
458 * never complete. Resetting the I2C master does not help. The only
459 * way is to force the bus through a series of transitions to make
460 * sure that all slaves are done with the transaction. This method
461 * performs this 'deblocking' if support by the driver.
463 * This method is optional.
465 int (*deblock)(struct udevice *bus);
468 #define i2c_get_ops(dev) ((struct dm_i2c_ops *)(dev)->driver->ops)
471 * struct i2c_mux_ops - operations for an I2C mux
473 * The current mux state is expected to be stored in the mux itself since
474 * it is the only thing that knows how to make things work. The mux can
475 * record the current state and then avoid switching unless it is necessary.
476 * So select() can be skipped if the mux is already in the correct state.
477 * Also deselect() can be made a nop if required.
481 * select() - select one of of I2C buses attached to a mux
483 * This will be called when there is no bus currently selected by the
484 * mux. This method does not need to deselect the old bus since
485 * deselect() will be already have been called if necessary.
488 * @bus: I2C bus to select
489 * @channel: Channel number correponding to the bus to select
490 * @return 0 if OK, -ve on error
492 int (*select)(struct udevice *mux, struct udevice *bus, uint channel);
495 * deselect() - select one of of I2C buses attached to a mux
497 * This is used to deselect the currently selected I2C bus.
500 * @bus: I2C bus to deselect
501 * @channel: Channel number correponding to the bus to deselect
502 * @return 0 if OK, -ve on error
504 int (*deselect)(struct udevice *mux, struct udevice *bus, uint channel);
507 #define i2c_mux_get_ops(dev) ((struct i2c_mux_ops *)(dev)->driver->ops)
510 * i2c_get_chip() - get a device to use to access a chip on a bus
512 * This returns the device for the given chip address. The device can then
513 * be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc.
515 * @bus: Bus to examine
516 * @chip_addr: Chip address for the new device
517 * @offset_len: Length of a register offset in bytes (normally 1)
518 * @devp: Returns pointer to new device if found or -ENODEV if not
521 int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
522 struct udevice **devp);
525 * i2c_get_chip_for_busnum() - get a device to use to access a chip on
528 * This returns the device for the given chip address on a particular bus
531 * @busnum: Bus number to examine
532 * @chip_addr: Chip address for the new device
533 * @offset_len: Length of a register offset in bytes (normally 1)
534 * @devp: Returns pointer to new device if found or -ENODEV if not
537 int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
538 struct udevice **devp);
541 * i2c_chip_of_to_plat() - Decode standard I2C platform data
543 * This decodes the chip address from a device tree node and puts it into
544 * its dm_i2c_chip structure. This should be called in your driver's
545 * of_to_plat() method.
547 * @blob: Device tree blob
548 * @node: Node offset to read from
549 * @spi: Place to put the decoded information
551 int i2c_chip_of_to_plat(struct udevice *dev, struct dm_i2c_chip *chip);
554 * i2c_dump_msgs() - Dump a list of I2C messages
556 * This may be useful for debugging.
558 * @msg: Message list to dump
559 * @nmsgs: Number of messages
561 void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs);
564 * i2c_emul_find() - Find an emulator for an i2c sandbox device
566 * This looks at the device's 'emul' phandle
568 * @dev: Device to find an emulator for
569 * @emulp: Returns the associated emulator, if found *
570 * @return 0 if OK, -ENOENT or -ENODEV if not found
572 int i2c_emul_find(struct udevice *dev, struct udevice **emulp);
575 * i2c_emul_set_idx() - Set the emulator index for an i2c sandbox device
577 * With of-platdata we cannot find the emulator using the device tree, so rely
578 * on the bind() method of each i2c driver calling this function to tell us
579 * the of-platdata idx of the emulator
581 * @dev: i2c device to set the emulator for
582 * @emul_idx: of-platdata index for that emulator
584 void i2c_emul_set_idx(struct udevice *dev, int emul_idx);
587 * i2c_emul_get_device() - Find the device being emulated
589 * Given an emulator this returns the associated device
591 * @emul: Emulator for the device
592 * @return device that @emul is emulating
594 struct udevice *i2c_emul_get_device(struct udevice *emul);
596 /* ACPI operations for generic I2C devices */
597 extern struct acpi_ops i2c_acpi_ops;
600 * acpi_i2c_of_to_plat() - Read properties intended for ACPI
602 * This reads the generic I2C properties from the device tree, so that these
603 * can be used to create ACPI information for the device.
605 * See the i2c/generic-acpi.txt binding file for information about the
608 * @dev: I2C device to process
609 * @return 0 if OK, -EINVAL if acpi,hid is not present
611 int acpi_i2c_of_to_plat(struct udevice *dev);
613 #ifdef CONFIG_SYS_I2C_EARLY_INIT
614 void i2c_early_init_f(void);
617 #if !CONFIG_IS_ENABLED(DM_I2C)
620 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
622 * The implementation MUST NOT use static or global variables if the
623 * I2C routines are used to read SDRAM configuration information
624 * because this is done before the memories are initialized. Limited
625 * use of stack-based variables are OK (the initial stack size is
628 * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
632 * Configuration items.
634 #define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
636 #if !defined(CONFIG_SYS_I2C_MAX_HOPS)
637 /* no muxes used bus = i2c adapters */
638 #define CONFIG_SYS_I2C_DIRECT_BUS 1
639 #define CONFIG_SYS_I2C_MAX_HOPS 0
640 #define CONFIG_SYS_NUM_I2C_BUSES ll_entry_count(struct i2c_adapter, i2c)
642 /* we use i2c muxes */
643 #undef CONFIG_SYS_I2C_DIRECT_BUS
646 /* define the I2C bus number for RTC and DTT if not already done */
647 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
648 #define CONFIG_SYS_RTC_BUS_NUM 0
650 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
651 #define CONFIG_SYS_SPD_BUS_NUM 0
655 void (*init)(struct i2c_adapter *adap, int speed,
657 int (*probe)(struct i2c_adapter *adap, uint8_t chip);
658 int (*read)(struct i2c_adapter *adap, uint8_t chip,
659 uint addr, int alen, uint8_t *buffer,
661 int (*write)(struct i2c_adapter *adap, uint8_t chip,
662 uint addr, int alen, uint8_t *buffer,
664 uint (*set_bus_speed)(struct i2c_adapter *adap,
674 #define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
675 _set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
681 .set_bus_speed = _set_speed, \
683 .slaveaddr = _slaveaddr, \
685 .hwadapnr = _hwadapnr, \
689 #define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
690 _set_speed, _speed, _slaveaddr, _hwadapnr) \
691 ll_entry_declare(struct i2c_adapter, _name, i2c) = \
692 U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
693 _set_speed, _speed, _slaveaddr, _hwadapnr, _name);
695 struct i2c_adapter *i2c_get_adapter(int index);
697 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
703 struct i2c_next_hop {
709 struct i2c_bus_hose {
711 struct i2c_next_hop next_hop[CONFIG_SYS_I2C_MAX_HOPS];
713 #define I2C_NULL_HOP {{-1, ""}, 0, 0}
714 extern struct i2c_bus_hose i2c_bus[];
716 #define I2C_ADAPTER(bus) i2c_bus[bus].adapter
718 #define I2C_ADAPTER(bus) bus
720 #define I2C_BUS gd->cur_i2c_bus
722 #define I2C_ADAP_NR(bus) i2c_get_adapter(I2C_ADAPTER(bus))
723 #define I2C_ADAP I2C_ADAP_NR(gd->cur_i2c_bus)
724 #define I2C_ADAP_HWNR (I2C_ADAP->hwadapnr)
726 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
727 #define I2C_MUX_PCA9540_ID 1
728 #define I2C_MUX_PCA9540 {I2C_MUX_PCA9540_ID, "PCA9540B"}
729 #define I2C_MUX_PCA9542_ID 2
730 #define I2C_MUX_PCA9542 {I2C_MUX_PCA9542_ID, "PCA9542A"}
731 #define I2C_MUX_PCA9544_ID 3
732 #define I2C_MUX_PCA9544 {I2C_MUX_PCA9544_ID, "PCA9544A"}
733 #define I2C_MUX_PCA9547_ID 4
734 #define I2C_MUX_PCA9547 {I2C_MUX_PCA9547_ID, "PCA9547A"}
735 #define I2C_MUX_PCA9548_ID 5
736 #define I2C_MUX_PCA9548 {I2C_MUX_PCA9548_ID, "PCA9548"}
739 #ifndef I2C_SOFT_DECLARATIONS
740 # if (defined(CONFIG_AT91RM9200) || \
741 defined(CONFIG_AT91SAM9260) || defined(CONFIG_AT91SAM9261) || \
742 defined(CONFIG_AT91SAM9263))
743 # define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) ATMEL_BASE_PIOA;
745 # define I2C_SOFT_DECLARATIONS
750 * Initialization, must be called once on start up, may be called
751 * repeatedly to change the speed and slave addresses.
753 void i2c_init(int speed, int slaveaddr);
754 void i2c_init_board(void);
756 #if CONFIG_IS_ENABLED(SYS_I2C_LEGACY)
760 * Returns index of currently active I2C bus. Zero-based.
762 unsigned int i2c_get_bus_num(void);
767 * Change the active I2C bus. Subsequent read/write calls will
770 * bus - bus index, zero based
772 * Returns: 0 on success, not 0 on failure
775 int i2c_set_bus_num(unsigned int bus);
780 * Initializes all I2C adapters in the system. All i2c_adap structures must
781 * be initialized beforehead with function pointers and data, including
782 * speed and slaveaddr. Returns 0 on success, non-0 on failure.
784 void i2c_init_all(void);
787 * Probe the given I2C chip address. Returns 0 if a chip responded,
790 int i2c_probe(uint8_t chip);
793 * Read/Write interface:
794 * chip: I2C chip address, range 0..127
795 * addr: Memory (register) address within the chip
796 * alen: Number of bytes to use for addr (typically 1, 2 for larger
797 * memories, 0 for register type devices with only one
799 * buffer: Where to read/write the data
800 * len: How many bytes to read/write
802 * Returns: 0 on success, not 0 on failure
804 int i2c_read(uint8_t chip, unsigned int addr, int alen,
805 uint8_t *buffer, int len);
807 int i2c_write(uint8_t chip, unsigned int addr, int alen,
808 uint8_t *buffer, int len);
811 * Utility routines to read/write registers.
813 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
815 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
820 * Change the speed of the active I2C bus
822 * speed - bus speed in Hz
824 * Returns: new bus speed
827 unsigned int i2c_set_bus_speed(unsigned int speed);
832 * Returns speed of currently active I2C bus in Hz
835 unsigned int i2c_get_bus_speed(void);
840 * Probe the given I2C chip address. Returns 0 if a chip responded,
843 int i2c_probe(uchar chip);
846 * Read/Write interface:
847 * chip: I2C chip address, range 0..127
848 * addr: Memory (register) address within the chip
849 * alen: Number of bytes to use for addr (typically 1, 2 for larger
850 * memories, 0 for register type devices with only one
852 * buffer: Where to read/write the data
853 * len: How many bytes to read/write
855 * Returns: 0 on success, not 0 on failure
857 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
858 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
861 * Utility routines to read/write registers.
863 static inline u8 i2c_reg_read(u8 addr, u8 reg)
868 printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
871 i2c_read(addr, reg, 1, &buf, 1);
876 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
879 printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
880 __func__, addr, reg, val);
883 i2c_write(addr, reg, 1, &val, 1);
887 * Functions for setting the current I2C bus and its speed
893 * Change the active I2C bus. Subsequent read/write calls will
896 * bus - bus index, zero based
898 * Returns: 0 on success, not 0 on failure
901 int i2c_set_bus_num(unsigned int bus);
906 * Returns index of currently active I2C bus. Zero-based.
909 unsigned int i2c_get_bus_num(void);
914 * Change the speed of the active I2C bus
916 * speed - bus speed in Hz
918 * Returns: 0 on success, not 0 on failure
921 int i2c_set_bus_speed(unsigned int);
926 * Returns speed of currently active I2C bus in Hz
929 unsigned int i2c_get_bus_speed(void);
930 #endif /* CONFIG_SYS_I2C_LEGACY */
933 * only for backwardcompatibility, should go away if we switched
934 * completely to new multibus support.
936 #if CONFIG_IS_ENABLED(SYS_I2C_LEGACY) || defined(CONFIG_I2C_MULTI_BUS)
937 # if !defined(CONFIG_SYS_MAX_I2C_BUS)
938 # define CONFIG_SYS_MAX_I2C_BUS 2
940 # define I2C_MULTI_BUS 1
942 # define CONFIG_SYS_MAX_I2C_BUS 1
943 # define I2C_MULTI_BUS 0
946 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
947 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
948 static inline unsigned int I2C_GET_BUS(void)
950 return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
953 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
954 static inline void I2C_SET_BUS(unsigned int bus)
957 i2c_set_bus_num(bus);
960 /* Multi I2C definitions */
962 I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
963 I2C_8, I2C_9, I2C_10,
967 * Get FDT values for i2c bus.
969 * @param blob Device tree blbo
970 * @return the number of I2C bus
972 void board_i2c_init(const void *blob);
975 * Find the I2C bus number by given a FDT I2C node.
977 * @param blob Device tree blbo
978 * @param node FDT I2C node to find
979 * @return the number of I2C bus (zero based), or -1 on error
981 int i2c_get_bus_num_fdt(int node);
984 * Reset the I2C bus represented by the given a FDT I2C node.
986 * @param blob Device tree blbo
987 * @param node FDT I2C node to find
988 * @return 0 if port was reset, -1 if not found
990 int i2c_reset_port_fdt(const void *blob, int node);
992 #endif /* !CONFIG_DM_I2C */