• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
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.
6  *
7  * (C) Copyright 2001
8  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
9  *
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.
14  */
15 
16 #ifndef _I2C_H_
17 #define _I2C_H_
18 
19 /*
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.
25  */
26 
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 */
31 };
32 
33 struct udevice;
34 /**
35  * struct dm_i2c_chip - information about an i2c chip
36  *
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.
39  *
40  * To obtain this structure, use dev_get_parent_platdata(dev) where dev is
41  * the chip to examine.
42  *
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)
49  */
50 struct dm_i2c_chip {
51 	uint chip_addr;
52 	uint offset_len;
53 	uint flags;
54 #ifdef CONFIG_SANDBOX
55 	struct udevice *emul;
56 	bool test_mode;
57 #endif
58 };
59 
60 /**
61  * struct dm_i2c_bus- information about an i2c bus
62  *
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
65  * or 400KHz).
66  *
67  * To obtain this structure, use dev_get_uclass_priv(bus) where bus is the
68  * I2C bus udevice.
69  *
70  * @speed_hz: Bus speed in hertz (typically 100000)
71  * @max_transaction_bytes: Maximal size of single I2C transfer
72  */
73 struct dm_i2c_bus {
74 	int speed_hz;
75 	int max_transaction_bytes;
76 };
77 
78 /*
79  * Not all of these flags are implemented in the U-Boot API
80  */
81 enum dm_i2c_msg_flags {
82 	I2C_M_TEN		= 0x0010, /* ten-bit chip address */
83 	I2C_M_RD		= 0x0001, /* read data, from slave to master */
84 	I2C_M_STOP		= 0x8000, /* send stop after this message */
85 	I2C_M_NOSTART		= 0x4000, /* no start before this message */
86 	I2C_M_REV_DIR_ADDR	= 0x2000, /* invert polarity of R/W bit */
87 	I2C_M_IGNORE_NAK	= 0x1000, /* continue after NAK */
88 	I2C_M_NO_RD_ACK		= 0x0800, /* skip the Ack bit on reads */
89 	I2C_M_RECV_LEN		= 0x0400, /* length is first received byte */
90 };
91 
92 /**
93  * struct i2c_msg - an I2C message
94  *
95  * @addr:	Slave address
96  * @flags:	Flags (see enum dm_i2c_msg_flags)
97  * @len:	Length of buffer in bytes, may be 0 for a probe
98  * @buf:	Buffer to send/receive, or NULL if no data
99  */
100 struct i2c_msg {
101 	uint addr;
102 	uint flags;
103 	uint len;
104 	u8 *buf;
105 };
106 
107 /**
108  * struct i2c_msg_list - a list of I2C messages
109  *
110  * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
111  * appropriate in U-Boot.
112  *
113  * @msg:	Pointer to i2c_msg array
114  * @nmsgs:	Number of elements in the array
115  */
116 struct i2c_msg_list {
117 	struct i2c_msg *msgs;
118 	uint nmsgs;
119 };
120 
121 /**
122  * dm_i2c_read() - read bytes from an I2C chip
123  *
124  * To obtain an I2C device (called a 'chip') given the I2C bus address you
125  * can use i2c_get_chip(). To obtain a bus by bus number use
126  * uclass_get_device_by_seq(UCLASS_I2C, <bus number>).
127  *
128  * To set the address length of a devce use i2c_set_addr_len(). It
129  * defaults to 1.
130  *
131  * @dev:	Chip to read from
132  * @offset:	Offset within chip to start reading
133  * @buffer:	Place to put data
134  * @len:	Number of bytes to read
135  *
136  * @return 0 on success, -ve on failure
137  */
138 int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len);
139 
140 /**
141  * dm_i2c_write() - write bytes to an I2C chip
142  *
143  * See notes for dm_i2c_read() above.
144  *
145  * @dev:	Chip to write to
146  * @offset:	Offset within chip to start writing
147  * @buffer:	Buffer containing data to write
148  * @len:	Number of bytes to write
149  *
150  * @return 0 on success, -ve on failure
151  */
152 int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
153 		 int len);
154 
155 /**
156  * dm_i2c_probe() - probe a particular chip address
157  *
158  * This can be useful to check for the existence of a chip on the bus.
159  * It is typically implemented by writing the chip address to the bus
160  * and checking that the chip replies with an ACK.
161  *
162  * @bus:	Bus to probe
163  * @chip_addr:	7-bit address to probe (10-bit and others are not supported)
164  * @chip_flags:	Flags for the probe (see enum dm_i2c_chip_flags)
165  * @devp:	Returns the device found, or NULL if none
166  * @return 0 if a chip was found at that address, -ve if not
167  */
168 int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
169 		 struct udevice **devp);
170 
171 /**
172  * dm_i2c_reg_read() - Read a value from an I2C register
173  *
174  * This reads a single value from the given address in an I2C chip
175  *
176  * @dev:	Device to use for transfer
177  * @addr:	Address to read from
178  * @return value read, or -ve on error
179  */
180 int dm_i2c_reg_read(struct udevice *dev, uint offset);
181 
182 /**
183  * dm_i2c_reg_write() - Write a value to an I2C register
184  *
185  * This writes a single value to the given address in an I2C chip
186  *
187  * @dev:	Device to use for transfer
188  * @addr:	Address to write to
189  * @val:	Value to write (normally a byte)
190  * @return 0 on success, -ve on error
191  */
192 int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
193 
194 /**
195  * dm_i2c_xfer() - Transfer messages over I2C
196  *
197  * This transfers a raw message. It is best to use dm_i2c_reg_read/write()
198  * instead.
199  *
200  * @dev:	Device to use for transfer
201  * @msg:	List of messages to transfer
202  * @nmsgs:	Number of messages to transfer
203  * @return 0 on success, -ve on error
204  */
205 int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs);
206 
207 /**
208  * dm_i2c_set_bus_speed() - set the speed of a bus
209  *
210  * @bus:	Bus to adjust
211  * @speed:	Requested speed in Hz
212  * @return 0 if OK, -EINVAL for invalid values
213  */
214 int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
215 
216 /**
217  * dm_i2c_get_bus_speed() - get the speed of a bus
218  *
219  * @bus:	Bus to check
220  * @return speed of selected I2C bus in Hz, -ve on error
221  */
222 int dm_i2c_get_bus_speed(struct udevice *bus);
223 
224 /**
225  * i2c_set_chip_flags() - set flags for a chip
226  *
227  * Typically addresses are 7 bits, but for 10-bit addresses you should set
228  * flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
229  *
230  * @dev:	Chip to adjust
231  * @flags:	New flags
232  * @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
233  */
234 int i2c_set_chip_flags(struct udevice *dev, uint flags);
235 
236 /**
237  * i2c_get_chip_flags() - get flags for a chip
238  *
239  * @dev:	Chip to check
240  * @flagsp:	Place to put flags
241  * @return 0 if OK, other -ve value on error
242  */
243 int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
244 
245 /**
246  * i2c_set_offset_len() - set the offset length for a chip
247  *
248  * The offset used to access a chip may be up to 4 bytes long. Typically it
249  * is only 1 byte, which is enough for chips with 256 bytes of memory or
250  * registers. The default value is 1, but you can call this function to
251  * change it.
252  *
253  * @offset_len:	New offset length value (typically 1 or 2)
254  */
255 int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
256 
257 /**
258  * i2c_get_offset_len() - get the offset length for a chip
259  *
260  * @return:	Current offset length value (typically 1 or 2)
261  */
262 int i2c_get_chip_offset_len(struct udevice *dev);
263 
264 /**
265  * i2c_deblock() - recover a bus that is in an unknown state
266  *
267  * See the deblock() method in 'struct dm_i2c_ops' for full information
268  *
269  * @bus:	Bus to recover
270  * @return 0 if OK, -ve on error
271  */
272 int i2c_deblock(struct udevice *bus);
273 
274 /**
275  * struct dm_i2c_ops - driver operations for I2C uclass
276  *
277  * Drivers should support these operations unless otherwise noted. These
278  * operations are intended to be used by uclass code, not directly from
279  * other code.
280  */
281 struct dm_i2c_ops {
282 	/**
283 	 * xfer() - transfer a list of I2C messages
284 	 *
285 	 * @bus:	Bus to read from
286 	 * @msg:	List of messages to transfer
287 	 * @nmsgs:	Number of messages in the list
288 	 * @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
289 	 *	-ECOMM if the speed cannot be supported, -EPROTO if the chip
290 	 *	flags cannot be supported, other -ve value on some other error
291 	 */
292 	int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
293 
294 	/**
295 	 * probe_chip() - probe for the presense of a chip address
296 	 *
297 	 * This function is optional. If omitted, the uclass will send a zero
298 	 * length message instead.
299 	 *
300 	 * @bus:	Bus to probe
301 	 * @chip_addr:	Chip address to probe
302 	 * @chip_flags:	Probe flags (enum dm_i2c_chip_flags)
303 	 * @return 0 if chip was found, -EREMOTEIO if not, -ENOSYS to fall back
304 	 * to default probem other -ve value on error
305 	 */
306 	int (*probe_chip)(struct udevice *bus, uint chip_addr, uint chip_flags);
307 
308 	/**
309 	 * set_bus_speed() - set the speed of a bus (optional)
310 	 *
311 	 * The bus speed value will be updated by the uclass if this function
312 	 * does not return an error. This method is optional - if it is not
313 	 * provided then the driver can read the speed from
314 	 * dev_get_uclass_priv(bus)->speed_hz
315 	 *
316 	 * @bus:	Bus to adjust
317 	 * @speed:	Requested speed in Hz
318 	 * @return 0 if OK, -EINVAL for invalid values
319 	 */
320 	int (*set_bus_speed)(struct udevice *bus, unsigned int speed);
321 
322 	/**
323 	 * get_bus_speed() - get the speed of a bus (optional)
324 	 *
325 	 * Normally this can be provided by the uclass, but if you want your
326 	 * driver to check the bus speed by looking at the hardware, you can
327 	 * implement that here. This method is optional. This method would
328 	 * normally be expected to return dev_get_uclass_priv(bus)->speed_hz.
329 	 *
330 	 * @bus:	Bus to check
331 	 * @return speed of selected I2C bus in Hz, -ve on error
332 	 */
333 	int (*get_bus_speed)(struct udevice *bus);
334 
335 	/**
336 	 * set_flags() - set the flags for a chip (optional)
337 	 *
338 	 * This is generally implemented by the uclass, but drivers can
339 	 * check the value to ensure that unsupported options are not used.
340 	 * This method is optional. If provided, this method will always be
341 	 * called when the flags change.
342 	 *
343 	 * @dev:	Chip to adjust
344 	 * @flags:	New flags value
345 	 * @return 0 if OK, -EINVAL if value is unsupported
346 	 */
347 	int (*set_flags)(struct udevice *dev, uint flags);
348 
349 	/**
350 	 * deblock() - recover a bus that is in an unknown state
351 	 *
352 	 * I2C is a synchronous protocol and resets of the processor in the
353 	 * middle of an access can block the I2C Bus until a powerdown of
354 	 * the full unit is done. This is because slaves can be stuck
355 	 * waiting for addition bus transitions for a transaction that will
356 	 * never complete. Resetting the I2C master does not help. The only
357 	 * way is to force the bus through a series of transitions to make
358 	 * sure that all slaves are done with the transaction. This method
359 	 * performs this 'deblocking' if support by the driver.
360 	 *
361 	 * This method is optional.
362 	 */
363 	int (*deblock)(struct udevice *bus);
364 };
365 
366 #define i2c_get_ops(dev)	((struct dm_i2c_ops *)(dev)->driver->ops)
367 
368 /**
369  * struct i2c_mux_ops - operations for an I2C mux
370  *
371  * The current mux state is expected to be stored in the mux itself since
372  * it is the only thing that knows how to make things work. The mux can
373  * record the current state and then avoid switching unless it is necessary.
374  * So select() can be skipped if the mux is already in the correct state.
375  * Also deselect() can be made a nop if required.
376  */
377 struct i2c_mux_ops {
378 	/**
379 	 * select() - select one of of I2C buses attached to a mux
380 	 *
381 	 * This will be called when there is no bus currently selected by the
382 	 * mux. This method does not need to deselect the old bus since
383 	 * deselect() will be already have been called if necessary.
384 	 *
385 	 * @mux:	Mux device
386 	 * @bus:	I2C bus to select
387 	 * @channel:	Channel number correponding to the bus to select
388 	 * @return 0 if OK, -ve on error
389 	 */
390 	int (*select)(struct udevice *mux, struct udevice *bus, uint channel);
391 
392 	/**
393 	 * deselect() - select one of of I2C buses attached to a mux
394 	 *
395 	 * This is used to deselect the currently selected I2C bus.
396 	 *
397 	 * @mux:	Mux device
398 	 * @bus:	I2C bus to deselect
399 	 * @channel:	Channel number correponding to the bus to deselect
400 	 * @return 0 if OK, -ve on error
401 	 */
402 	int (*deselect)(struct udevice *mux, struct udevice *bus, uint channel);
403 };
404 
405 #define i2c_mux_get_ops(dev)	((struct i2c_mux_ops *)(dev)->driver->ops)
406 
407 /**
408  * i2c_get_chip() - get a device to use to access a chip on a bus
409  *
410  * This returns the device for the given chip address. The device can then
411  * be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc.
412  *
413  * @bus:	Bus to examine
414  * @chip_addr:	Chip address for the new device
415  * @offset_len:	Length of a register offset in bytes (normally 1)
416  * @devp:	Returns pointer to new device if found or -ENODEV if not
417  *		found
418  */
419 int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
420 		 struct udevice **devp);
421 
422 /**
423  * i2c_get_chip_for_busnum() - get a device to use to access a chip on
424  *			       a bus number
425  *
426  * This returns the device for the given chip address on a particular bus
427  * number.
428  *
429  * @busnum:	Bus number to examine
430  * @chip_addr:	Chip address for the new device
431  * @offset_len:	Length of a register offset in bytes (normally 1)
432  * @devp:	Returns pointer to new device if found or -ENODEV if not
433  *		found
434  */
435 int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
436 			    struct udevice **devp);
437 
438 /**
439  * i2c_chip_ofdata_to_platdata() - Decode standard I2C platform data
440  *
441  * This decodes the chip address from a device tree node and puts it into
442  * its dm_i2c_chip structure. This should be called in your driver's
443  * ofdata_to_platdata() method.
444  *
445  * @blob:	Device tree blob
446  * @node:	Node offset to read from
447  * @spi:	Place to put the decoded information
448  */
449 int i2c_chip_ofdata_to_platdata(struct udevice *dev, struct dm_i2c_chip *chip);
450 
451 /**
452  * i2c_dump_msgs() - Dump a list of I2C messages
453  *
454  * This may be useful for debugging.
455  *
456  * @msg:	Message list to dump
457  * @nmsgs:	Number of messages
458  */
459 void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs);
460 
461 /**
462  * i2c_emul_find() - Find an emulator for an i2c sandbox device
463  *
464  * This looks at the device's 'emul' phandle
465  *
466  * @dev: Device to find an emulator for
467  * @emulp: Returns the associated emulator, if found *
468  * @return 0 if OK, -ENOENT or -ENODEV if not found
469  */
470 int i2c_emul_find(struct udevice *dev, struct udevice **emulp);
471 
472 /**
473  * i2c_emul_get_device() - Find the device being emulated
474  *
475  * Given an emulator this returns the associated device
476  *
477  * @emul: Emulator for the device
478  * @return device that @emul is emulating
479  */
480 struct udevice *i2c_emul_get_device(struct udevice *emul);
481 
482 #ifndef CONFIG_DM_I2C
483 
484 /*
485  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
486  *
487  * The implementation MUST NOT use static or global variables if the
488  * I2C routines are used to read SDRAM configuration information
489  * because this is done before the memories are initialized. Limited
490  * use of stack-based variables are OK (the initial stack size is
491  * limited).
492  *
493  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
494  */
495 
496 /*
497  * Configuration items.
498  */
499 #define I2C_RXTX_LEN	128	/* maximum tx/rx buffer length */
500 
501 #if !defined(CONFIG_SYS_I2C_MAX_HOPS)
502 /* no muxes used bus = i2c adapters */
503 #define CONFIG_SYS_I2C_DIRECT_BUS	1
504 #define CONFIG_SYS_I2C_MAX_HOPS		0
505 #define CONFIG_SYS_NUM_I2C_BUSES	ll_entry_count(struct i2c_adapter, i2c)
506 #else
507 /* we use i2c muxes */
508 #undef CONFIG_SYS_I2C_DIRECT_BUS
509 #endif
510 
511 /* define the I2C bus number for RTC and DTT if not already done */
512 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
513 #define CONFIG_SYS_RTC_BUS_NUM		0
514 #endif
515 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
516 #define CONFIG_SYS_SPD_BUS_NUM		0
517 #endif
518 
519 struct i2c_adapter {
520 	void		(*init)(struct i2c_adapter *adap, int speed,
521 				int slaveaddr);
522 	int		(*probe)(struct i2c_adapter *adap, uint8_t chip);
523 	int		(*read)(struct i2c_adapter *adap, uint8_t chip,
524 				uint addr, int alen, uint8_t *buffer,
525 				int len);
526 	int		(*write)(struct i2c_adapter *adap, uint8_t chip,
527 				uint addr, int alen, uint8_t *buffer,
528 				int len);
529 	uint		(*set_bus_speed)(struct i2c_adapter *adap,
530 				uint speed);
531 	int		speed;
532 	int		waitdelay;
533 	int		slaveaddr;
534 	int		init_done;
535 	int		hwadapnr;
536 	char		*name;
537 };
538 
539 #define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
540 		_set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
541 	{ \
542 		.init		=	_init, \
543 		.probe		=	_probe, \
544 		.read		=	_read, \
545 		.write		=	_write, \
546 		.set_bus_speed	=	_set_speed, \
547 		.speed		=	_speed, \
548 		.slaveaddr	=	_slaveaddr, \
549 		.init_done	=	0, \
550 		.hwadapnr	=	_hwadapnr, \
551 		.name		=	#_name \
552 };
553 
554 #define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
555 			_set_speed, _speed, _slaveaddr, _hwadapnr) \
556 	ll_entry_declare(struct i2c_adapter, _name, i2c) = \
557 	U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
558 		 _set_speed, _speed, _slaveaddr, _hwadapnr, _name);
559 
560 struct i2c_adapter *i2c_get_adapter(int index);
561 
562 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
563 struct i2c_mux {
564 	int	id;
565 	char	name[16];
566 };
567 
568 struct i2c_next_hop {
569 	struct i2c_mux		mux;
570 	uint8_t		chip;
571 	uint8_t		channel;
572 };
573 
574 struct i2c_bus_hose {
575 	int	adapter;
576 	struct i2c_next_hop	next_hop[CONFIG_SYS_I2C_MAX_HOPS];
577 };
578 #define I2C_NULL_HOP	{{-1, ""}, 0, 0}
579 extern struct i2c_bus_hose	i2c_bus[];
580 
581 #define I2C_ADAPTER(bus)	i2c_bus[bus].adapter
582 #else
583 #define I2C_ADAPTER(bus)	bus
584 #endif
585 #define	I2C_BUS			gd->cur_i2c_bus
586 
587 #define	I2C_ADAP_NR(bus)	i2c_get_adapter(I2C_ADAPTER(bus))
588 #define	I2C_ADAP		I2C_ADAP_NR(gd->cur_i2c_bus)
589 #define I2C_ADAP_HWNR		(I2C_ADAP->hwadapnr)
590 
591 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
592 #define I2C_MUX_PCA9540_ID	1
593 #define I2C_MUX_PCA9540		{I2C_MUX_PCA9540_ID, "PCA9540B"}
594 #define I2C_MUX_PCA9542_ID	2
595 #define I2C_MUX_PCA9542		{I2C_MUX_PCA9542_ID, "PCA9542A"}
596 #define I2C_MUX_PCA9544_ID	3
597 #define I2C_MUX_PCA9544		{I2C_MUX_PCA9544_ID, "PCA9544A"}
598 #define I2C_MUX_PCA9547_ID	4
599 #define I2C_MUX_PCA9547		{I2C_MUX_PCA9547_ID, "PCA9547A"}
600 #define I2C_MUX_PCA9548_ID	5
601 #define I2C_MUX_PCA9548		{I2C_MUX_PCA9548_ID, "PCA9548"}
602 #endif
603 
604 #ifndef I2C_SOFT_DECLARATIONS
605 # if (defined(CONFIG_AT91RM9200) || \
606 	defined(CONFIG_AT91SAM9260) ||  defined(CONFIG_AT91SAM9261) || \
607 	defined(CONFIG_AT91SAM9263))
608 #  define I2C_SOFT_DECLARATIONS	at91_pio_t *pio	= (at91_pio_t *) ATMEL_BASE_PIOA;
609 # else
610 #  define I2C_SOFT_DECLARATIONS
611 # endif
612 #endif
613 
614 /*
615  * Many boards/controllers/drivers don't support an I2C slave interface so
616  * provide a default slave address for them for use in common code.  A real
617  * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
618  * support a slave interface.
619  */
620 #ifndef	CONFIG_SYS_I2C_SLAVE
621 #define	CONFIG_SYS_I2C_SLAVE	0xfe
622 #endif
623 
624 /*
625  * Initialization, must be called once on start up, may be called
626  * repeatedly to change the speed and slave addresses.
627  */
628 #ifdef CONFIG_SYS_I2C_EARLY_INIT
629 void i2c_early_init_f(void);
630 #endif
631 void i2c_init(int speed, int slaveaddr);
632 void i2c_init_board(void);
633 
634 #ifdef CONFIG_SYS_I2C
635 /*
636  * i2c_get_bus_num:
637  *
638  *  Returns index of currently active I2C bus.  Zero-based.
639  */
640 unsigned int i2c_get_bus_num(void);
641 
642 /*
643  * i2c_set_bus_num:
644  *
645  *  Change the active I2C bus.  Subsequent read/write calls will
646  *  go to this one.
647  *
648  *	bus - bus index, zero based
649  *
650  *	Returns: 0 on success, not 0 on failure
651  *
652  */
653 int i2c_set_bus_num(unsigned int bus);
654 
655 /*
656  * i2c_init_all():
657  *
658  * Initializes all I2C adapters in the system. All i2c_adap structures must
659  * be initialized beforehead with function pointers and data, including
660  * speed and slaveaddr. Returns 0 on success, non-0 on failure.
661  */
662 void i2c_init_all(void);
663 
664 /*
665  * Probe the given I2C chip address.  Returns 0 if a chip responded,
666  * not 0 on failure.
667  */
668 int i2c_probe(uint8_t chip);
669 
670 /*
671  * Read/Write interface:
672  *   chip:    I2C chip address, range 0..127
673  *   addr:    Memory (register) address within the chip
674  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
675  *              memories, 0 for register type devices with only one
676  *              register)
677  *   buffer:  Where to read/write the data
678  *   len:     How many bytes to read/write
679  *
680  *   Returns: 0 on success, not 0 on failure
681  */
682 int i2c_read(uint8_t chip, unsigned int addr, int alen,
683 				uint8_t *buffer, int len);
684 
685 int i2c_write(uint8_t chip, unsigned int addr, int alen,
686 				uint8_t *buffer, int len);
687 
688 /*
689  * Utility routines to read/write registers.
690  */
691 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
692 
693 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
694 
695 /*
696  * i2c_set_bus_speed:
697  *
698  *  Change the speed of the active I2C bus
699  *
700  *	speed - bus speed in Hz
701  *
702  *	Returns: new bus speed
703  *
704  */
705 unsigned int i2c_set_bus_speed(unsigned int speed);
706 
707 /*
708  * i2c_get_bus_speed:
709  *
710  *  Returns speed of currently active I2C bus in Hz
711  */
712 
713 unsigned int i2c_get_bus_speed(void);
714 
715 #else
716 
717 /*
718  * Probe the given I2C chip address.  Returns 0 if a chip responded,
719  * not 0 on failure.
720  */
721 int i2c_probe(uchar chip);
722 
723 /*
724  * Read/Write interface:
725  *   chip:    I2C chip address, range 0..127
726  *   addr:    Memory (register) address within the chip
727  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
728  *              memories, 0 for register type devices with only one
729  *              register)
730  *   buffer:  Where to read/write the data
731  *   len:     How many bytes to read/write
732  *
733  *   Returns: 0 on success, not 0 on failure
734  */
735 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
736 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
737 
738 /*
739  * Utility routines to read/write registers.
740  */
i2c_reg_read(u8 addr,u8 reg)741 static inline u8 i2c_reg_read(u8 addr, u8 reg)
742 {
743 	u8 buf;
744 
745 #ifdef DEBUG
746 	printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
747 #endif
748 
749 	i2c_read(addr, reg, 1, &buf, 1);
750 
751 	return buf;
752 }
753 
i2c_reg_write(u8 addr,u8 reg,u8 val)754 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
755 {
756 #ifdef DEBUG
757 	printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
758 	       __func__, addr, reg, val);
759 #endif
760 
761 	i2c_write(addr, reg, 1, &val, 1);
762 }
763 
764 /*
765  * Functions for setting the current I2C bus and its speed
766  */
767 
768 /*
769  * i2c_set_bus_num:
770  *
771  *  Change the active I2C bus.  Subsequent read/write calls will
772  *  go to this one.
773  *
774  *	bus - bus index, zero based
775  *
776  *	Returns: 0 on success, not 0 on failure
777  *
778  */
779 int i2c_set_bus_num(unsigned int bus);
780 
781 /*
782  * i2c_get_bus_num:
783  *
784  *  Returns index of currently active I2C bus.  Zero-based.
785  */
786 
787 unsigned int i2c_get_bus_num(void);
788 
789 /*
790  * i2c_set_bus_speed:
791  *
792  *  Change the speed of the active I2C bus
793  *
794  *	speed - bus speed in Hz
795  *
796  *	Returns: 0 on success, not 0 on failure
797  *
798  */
799 int i2c_set_bus_speed(unsigned int);
800 
801 /*
802  * i2c_get_bus_speed:
803  *
804  *  Returns speed of currently active I2C bus in Hz
805  */
806 
807 unsigned int i2c_get_bus_speed(void);
808 #endif /* CONFIG_SYS_I2C */
809 
810 /*
811  * only for backwardcompatibility, should go away if we switched
812  * completely to new multibus support.
813  */
814 #if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)
815 # if !defined(CONFIG_SYS_MAX_I2C_BUS)
816 #  define CONFIG_SYS_MAX_I2C_BUS		2
817 # endif
818 # define I2C_MULTI_BUS				1
819 #else
820 # define CONFIG_SYS_MAX_I2C_BUS		1
821 # define I2C_MULTI_BUS				0
822 #endif
823 
824 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
825 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
I2C_GET_BUS(void)826 static inline unsigned int I2C_GET_BUS(void)
827 {
828 	return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
829 }
830 
831 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
I2C_SET_BUS(unsigned int bus)832 static inline void I2C_SET_BUS(unsigned int bus)
833 {
834 	if (I2C_MULTI_BUS)
835 		i2c_set_bus_num(bus);
836 }
837 
838 /* Multi I2C definitions */
839 enum {
840 	I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
841 	I2C_8, I2C_9, I2C_10,
842 };
843 
844 /**
845  * Get FDT values for i2c bus.
846  *
847  * @param blob  Device tree blbo
848  * @return the number of I2C bus
849  */
850 void board_i2c_init(const void *blob);
851 
852 /**
853  * Find the I2C bus number by given a FDT I2C node.
854  *
855  * @param blob  Device tree blbo
856  * @param node  FDT I2C node to find
857  * @return the number of I2C bus (zero based), or -1 on error
858  */
859 int i2c_get_bus_num_fdt(int node);
860 
861 /**
862  * Reset the I2C bus represented by the given a FDT I2C node.
863  *
864  * @param blob  Device tree blbo
865  * @param node  FDT I2C node to find
866  * @return 0 if port was reset, -1 if not found
867  */
868 int i2c_reset_port_fdt(const void *blob, int node);
869 
870 #endif /* !CONFIG_DM_I2C */
871 
872 #endif	/* _I2C_H_ */
873