xref: /openbmc/u-boot/include/i2c.h (revision f9a4c2da)
1 /*
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.
5  *
6  * (C) Copyright 2001
7  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
8  *
9  * SPDX-License-Identifier:	GPL-2.0+
10  *
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.
15  */
16 
17 #ifndef _I2C_H_
18 #define _I2C_H_
19 
20 /*
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.
26  */
27 
28 #ifdef CONFIG_DM_I2C
29 
30 enum dm_i2c_chip_flags {
31 	DM_I2C_CHIP_10BIT	= 1 << 0, /* Use 10-bit addressing */
32 	DM_I2C_CHIP_RD_ADDRESS	= 1 << 1, /* Send address for each read byte */
33 	DM_I2C_CHIP_WR_ADDRESS	= 1 << 2, /* Send address for each write byte */
34 };
35 
36 /**
37  * struct dm_i2c_chip - information about an i2c chip
38  *
39  * An I2C chip is a device on the I2C bus. It sits at a particular address
40  * and normally supports 7-bit or 10-bit addressing.
41  *
42  * To obtain this structure, use dev_get_parentdata(dev) where dev is the
43  * chip to examine.
44  *
45  * @chip_addr:	Chip address on bus
46  * @offset_len: Length of offset in bytes. A single byte offset can
47  *		represent up to 256 bytes. A value larger than 1 may be
48  *		needed for larger devices.
49  * @flags:	Flags for this chip (dm_i2c_chip_flags)
50  * @emul: Emulator for this chip address (only used for emulation)
51  */
52 struct dm_i2c_chip {
53 	uint chip_addr;
54 	uint offset_len;
55 	uint flags;
56 #ifdef CONFIG_SANDBOX
57 	struct udevice *emul;
58 #endif
59 };
60 
61 /**
62  * struct dm_i2c_bus- information about an i2c bus
63  *
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
66  * or 400KHz).
67  *
68  * To obtain this structure, use bus->uclass_priv where bus is the I2C
69  * bus udevice.
70  *
71  * @speed_hz: Bus speed in hertz (typically 100000)
72  */
73 struct dm_i2c_bus {
74 	int speed_hz;
75 };
76 
77 /**
78  * dm_i2c_read() - read bytes from an I2C chip
79  *
80  * To obtain an I2C device (called a 'chip') given the I2C bus address you
81  * can use i2c_get_chip(). To obtain a bus by bus number use
82  * uclass_get_device_by_seq(UCLASS_I2C, <bus number>).
83  *
84  * To set the address length of a devce use i2c_set_addr_len(). It
85  * defaults to 1.
86  *
87  * @dev:	Chip to read from
88  * @offset:	Offset within chip to start reading
89  * @buffer:	Place to put data
90  * @len:	Number of bytes to read
91  *
92  * @return 0 on success, -ve on failure
93  */
94 int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len);
95 
96 /**
97  * dm_i2c_write() - write bytes to an I2C chip
98  *
99  * See notes for dm_i2c_read() above.
100  *
101  * @dev:	Chip to write to
102  * @offset:	Offset within chip to start writing
103  * @buffer:	Buffer containing data to write
104  * @len:	Number of bytes to write
105  *
106  * @return 0 on success, -ve on failure
107  */
108 int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
109 		 int len);
110 
111 /**
112  * dm_i2c_probe() - probe a particular chip address
113  *
114  * This can be useful to check for the existence of a chip on the bus.
115  * It is typically implemented by writing the chip address to the bus
116  * and checking that the chip replies with an ACK.
117  *
118  * @bus:	Bus to probe
119  * @chip_addr:	7-bit address to probe (10-bit and others are not supported)
120  * @chip_flags:	Flags for the probe (see enum dm_i2c_chip_flags)
121  * @devp:	Returns the device found, or NULL if none
122  * @return 0 if a chip was found at that address, -ve if not
123  */
124 int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
125 		 struct udevice **devp);
126 
127 /**
128  * i2c_set_bus_speed() - set the speed of a bus
129  *
130  * @bus:	Bus to adjust
131  * @speed:	Requested speed in Hz
132  * @return 0 if OK, -EINVAL for invalid values
133  */
134 int i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
135 
136 /**
137  * i2c_get_bus_speed() - get the speed of a bus
138  *
139  * @bus:	Bus to check
140  * @return speed of selected I2C bus in Hz, -ve on error
141  */
142 int i2c_get_bus_speed(struct udevice *bus);
143 
144 /**
145  * i2c_set_chip_flags() - set flags for a chip
146  *
147  * Typically addresses are 7 bits, but for 10-bit addresses you should set
148  * flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
149  *
150  * @dev:	Chip to adjust
151  * @flags:	New flags
152  * @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
153  */
154 int i2c_set_chip_flags(struct udevice *dev, uint flags);
155 
156 /**
157  * i2c_get_chip_flags() - get flags for a chip
158  *
159  * @dev:	Chip to check
160  * @flagsp:	Place to put flags
161  * @return 0 if OK, other -ve value on error
162  */
163 int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
164 
165 /**
166  * i2c_set_offset_len() - set the offset length for a chip
167  *
168  * The offset used to access a chip may be up to 4 bytes long. Typically it
169  * is only 1 byte, which is enough for chips with 256 bytes of memory or
170  * registers. The default value is 1, but you can call this function to
171  * change it.
172  *
173  * @offset_len:	New offset length value (typically 1 or 2)
174  */
175 
176 int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
177 /**
178  * i2c_deblock() - recover a bus that is in an unknown state
179  *
180  * See the deblock() method in 'struct dm_i2c_ops' for full information
181  *
182  * @bus:	Bus to recover
183  * @return 0 if OK, -ve on error
184  */
185 int i2c_deblock(struct udevice *bus);
186 
187 /*
188  * Not all of these flags are implemented in the U-Boot API
189  */
190 enum dm_i2c_msg_flags {
191 	I2C_M_TEN		= 0x0010, /* ten-bit chip address */
192 	I2C_M_RD		= 0x0001, /* read data, from slave to master */
193 	I2C_M_STOP		= 0x8000, /* send stop after this message */
194 	I2C_M_NOSTART		= 0x4000, /* no start before this message */
195 	I2C_M_REV_DIR_ADDR	= 0x2000, /* invert polarity of R/W bit */
196 	I2C_M_IGNORE_NAK	= 0x1000, /* continue after NAK */
197 	I2C_M_NO_RD_ACK		= 0x0800, /* skip the Ack bit on reads */
198 	I2C_M_RECV_LEN		= 0x0400, /* length is first received byte */
199 };
200 
201 /**
202  * struct i2c_msg - an I2C message
203  *
204  * @addr:	Slave address
205  * @flags:	Flags (see enum dm_i2c_msg_flags)
206  * @len:	Length of buffer in bytes, may be 0 for a probe
207  * @buf:	Buffer to send/receive, or NULL if no data
208  */
209 struct i2c_msg {
210 	uint addr;
211 	uint flags;
212 	uint len;
213 	u8 *buf;
214 };
215 
216 /**
217  * struct i2c_msg_list - a list of I2C messages
218  *
219  * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
220  * appropriate in U-Boot.
221  *
222  * @msg:	Pointer to i2c_msg array
223  * @nmsgs:	Number of elements in the array
224  */
225 struct i2c_msg_list {
226 	struct i2c_msg *msgs;
227 	uint nmsgs;
228 };
229 
230 /**
231  * struct dm_i2c_ops - driver operations for I2C uclass
232  *
233  * Drivers should support these operations unless otherwise noted. These
234  * operations are intended to be used by uclass code, not directly from
235  * other code.
236  */
237 struct dm_i2c_ops {
238 	/**
239 	 * xfer() - transfer a list of I2C messages
240 	 *
241 	 * @bus:	Bus to read from
242 	 * @msg:	List of messages to transfer
243 	 * @nmsgs:	Number of messages in the list
244 	 * @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
245 	 *	-ECOMM if the speed cannot be supported, -EPROTO if the chip
246 	 *	flags cannot be supported, other -ve value on some other error
247 	 */
248 	int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
249 
250 	/**
251 	 * probe_chip() - probe for the presense of a chip address
252 	 *
253 	 * This function is optional. If omitted, the uclass will send a zero
254 	 * length message instead.
255 	 *
256 	 * @bus:	Bus to probe
257 	 * @chip_addr:	Chip address to probe
258 	 * @chip_flags:	Probe flags (enum dm_i2c_chip_flags)
259 	 * @return 0 if chip was found, -EREMOTEIO if not, -ENOSYS to fall back
260 	 * to default probem other -ve value on error
261 	 */
262 	int (*probe_chip)(struct udevice *bus, uint chip_addr, uint chip_flags);
263 
264 	/**
265 	 * set_bus_speed() - set the speed of a bus (optional)
266 	 *
267 	 * The bus speed value will be updated by the uclass if this function
268 	 * does not return an error. This method is optional - if it is not
269 	 * provided then the driver can read the speed from
270 	 * bus->uclass_priv->speed_hz
271 	 *
272 	 * @bus:	Bus to adjust
273 	 * @speed:	Requested speed in Hz
274 	 * @return 0 if OK, -EINVAL for invalid values
275 	 */
276 	int (*set_bus_speed)(struct udevice *bus, unsigned int speed);
277 
278 	/**
279 	 * get_bus_speed() - get the speed of a bus (optional)
280 	 *
281 	 * Normally this can be provided by the uclass, but if you want your
282 	 * driver to check the bus speed by looking at the hardware, you can
283 	 * implement that here. This method is optional. This method would
284 	 * normally be expected to return bus->uclass_priv->speed_hz.
285 	 *
286 	 * @bus:	Bus to check
287 	 * @return speed of selected I2C bus in Hz, -ve on error
288 	 */
289 	int (*get_bus_speed)(struct udevice *bus);
290 
291 	/**
292 	 * set_flags() - set the flags for a chip (optional)
293 	 *
294 	 * This is generally implemented by the uclass, but drivers can
295 	 * check the value to ensure that unsupported options are not used.
296 	 * This method is optional. If provided, this method will always be
297 	 * called when the flags change.
298 	 *
299 	 * @dev:	Chip to adjust
300 	 * @flags:	New flags value
301 	 * @return 0 if OK, -EINVAL if value is unsupported
302 	 */
303 	int (*set_flags)(struct udevice *dev, uint flags);
304 
305 	/**
306 	 * deblock() - recover a bus that is in an unknown state
307 	 *
308 	 * I2C is a synchronous protocol and resets of the processor in the
309 	 * middle of an access can block the I2C Bus until a powerdown of
310 	 * the full unit is done. This is because slaves can be stuck
311 	 * waiting for addition bus transitions for a transaction that will
312 	 * never complete. Resetting the I2C master does not help. The only
313 	 * way is to force the bus through a series of transitions to make
314 	 * sure that all slaves are done with the transaction. This method
315 	 * performs this 'deblocking' if support by the driver.
316 	 *
317 	 * This method is optional.
318 	 */
319 	int (*deblock)(struct udevice *bus);
320 };
321 
322 #define i2c_get_ops(dev)	((struct dm_i2c_ops *)(dev)->driver->ops)
323 
324 /**
325  * i2c_get_chip() - get a device to use to access a chip on a bus
326  *
327  * This returns the device for the given chip address. The device can then
328  * be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc.
329  *
330  * @bus:	Bus to examine
331  * @chip_addr:	Chip address for the new device
332  * @devp:	Returns pointer to new device if found or -ENODEV if not
333  *		found
334  */
335 int i2c_get_chip(struct udevice *bus, uint chip_addr, struct udevice **devp);
336 
337 /**
338  * i2c_get_chip() - get a device to use to access a chip on a bus number
339  *
340  * This returns the device for the given chip address on a particular bus
341  * number.
342  *
343  * @busnum:	Bus number to examine
344  * @chip_addr:	Chip address for the new device
345  * @devp:	Returns pointer to new device if found or -ENODEV if not
346  *		found
347  */
348 int i2c_get_chip_for_busnum(int busnum, int chip_addr, struct udevice **devp);
349 
350 /**
351  * i2c_chip_ofdata_to_platdata() - Decode standard I2C platform data
352  *
353  * This decodes the chip address from a device tree node and puts it into
354  * its dm_i2c_chip structure. This should be called in your driver's
355  * ofdata_to_platdata() method.
356  *
357  * @blob:	Device tree blob
358  * @node:	Node offset to read from
359  * @spi:	Place to put the decoded information
360  */
361 int i2c_chip_ofdata_to_platdata(const void *blob, int node,
362 				struct dm_i2c_chip *chip);
363 
364 #endif
365 
366 #ifndef CONFIG_DM_I2C
367 
368 /*
369  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
370  *
371  * The implementation MUST NOT use static or global variables if the
372  * I2C routines are used to read SDRAM configuration information
373  * because this is done before the memories are initialized. Limited
374  * use of stack-based variables are OK (the initial stack size is
375  * limited).
376  *
377  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
378  */
379 
380 /*
381  * Configuration items.
382  */
383 #define I2C_RXTX_LEN	128	/* maximum tx/rx buffer length */
384 
385 #if !defined(CONFIG_SYS_I2C_MAX_HOPS)
386 /* no muxes used bus = i2c adapters */
387 #define CONFIG_SYS_I2C_DIRECT_BUS	1
388 #define CONFIG_SYS_I2C_MAX_HOPS		0
389 #define CONFIG_SYS_NUM_I2C_BUSES	ll_entry_count(struct i2c_adapter, i2c)
390 #else
391 /* we use i2c muxes */
392 #undef CONFIG_SYS_I2C_DIRECT_BUS
393 #endif
394 
395 /* define the I2C bus number for RTC and DTT if not already done */
396 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
397 #define CONFIG_SYS_RTC_BUS_NUM		0
398 #endif
399 #if !defined(CONFIG_SYS_DTT_BUS_NUM)
400 #define CONFIG_SYS_DTT_BUS_NUM		0
401 #endif
402 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
403 #define CONFIG_SYS_SPD_BUS_NUM		0
404 #endif
405 
406 struct i2c_adapter {
407 	void		(*init)(struct i2c_adapter *adap, int speed,
408 				int slaveaddr);
409 	int		(*probe)(struct i2c_adapter *adap, uint8_t chip);
410 	int		(*read)(struct i2c_adapter *adap, uint8_t chip,
411 				uint addr, int alen, uint8_t *buffer,
412 				int len);
413 	int		(*write)(struct i2c_adapter *adap, uint8_t chip,
414 				uint addr, int alen, uint8_t *buffer,
415 				int len);
416 	uint		(*set_bus_speed)(struct i2c_adapter *adap,
417 				uint speed);
418 	int		speed;
419 	int		waitdelay;
420 	int		slaveaddr;
421 	int		init_done;
422 	int		hwadapnr;
423 	char		*name;
424 };
425 
426 #define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
427 		_set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
428 	{ \
429 		.init		=	_init, \
430 		.probe		=	_probe, \
431 		.read		=	_read, \
432 		.write		=	_write, \
433 		.set_bus_speed	=	_set_speed, \
434 		.speed		=	_speed, \
435 		.slaveaddr	=	_slaveaddr, \
436 		.init_done	=	0, \
437 		.hwadapnr	=	_hwadapnr, \
438 		.name		=	#_name \
439 };
440 
441 #define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
442 			_set_speed, _speed, _slaveaddr, _hwadapnr) \
443 	ll_entry_declare(struct i2c_adapter, _name, i2c) = \
444 	U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
445 		 _set_speed, _speed, _slaveaddr, _hwadapnr, _name);
446 
447 struct i2c_adapter *i2c_get_adapter(int index);
448 
449 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
450 struct i2c_mux {
451 	int	id;
452 	char	name[16];
453 };
454 
455 struct i2c_next_hop {
456 	struct i2c_mux		mux;
457 	uint8_t		chip;
458 	uint8_t		channel;
459 };
460 
461 struct i2c_bus_hose {
462 	int	adapter;
463 	struct i2c_next_hop	next_hop[CONFIG_SYS_I2C_MAX_HOPS];
464 };
465 #define I2C_NULL_HOP	{{-1, ""}, 0, 0}
466 extern struct i2c_bus_hose	i2c_bus[];
467 
468 #define I2C_ADAPTER(bus)	i2c_bus[bus].adapter
469 #else
470 #define I2C_ADAPTER(bus)	bus
471 #endif
472 #define	I2C_BUS			gd->cur_i2c_bus
473 
474 #define	I2C_ADAP_NR(bus)	i2c_get_adapter(I2C_ADAPTER(bus))
475 #define	I2C_ADAP		I2C_ADAP_NR(gd->cur_i2c_bus)
476 #define I2C_ADAP_HWNR		(I2C_ADAP->hwadapnr)
477 
478 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
479 #define I2C_MUX_PCA9540_ID	1
480 #define I2C_MUX_PCA9540		{I2C_MUX_PCA9540_ID, "PCA9540B"}
481 #define I2C_MUX_PCA9542_ID	2
482 #define I2C_MUX_PCA9542		{I2C_MUX_PCA9542_ID, "PCA9542A"}
483 #define I2C_MUX_PCA9544_ID	3
484 #define I2C_MUX_PCA9544		{I2C_MUX_PCA9544_ID, "PCA9544A"}
485 #define I2C_MUX_PCA9547_ID	4
486 #define I2C_MUX_PCA9547		{I2C_MUX_PCA9547_ID, "PCA9547A"}
487 #define I2C_MUX_PCA9548_ID	5
488 #define I2C_MUX_PCA9548		{I2C_MUX_PCA9548_ID, "PCA9548"}
489 #endif
490 
491 #ifndef I2C_SOFT_DECLARATIONS
492 # if defined(CONFIG_MPC8260)
493 #  define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
494 # elif defined(CONFIG_8xx)
495 #  define I2C_SOFT_DECLARATIONS	volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
496 
497 # elif (defined(CONFIG_AT91RM9200) || \
498 	defined(CONFIG_AT91SAM9260) ||  defined(CONFIG_AT91SAM9261) || \
499 	defined(CONFIG_AT91SAM9263))
500 #  define I2C_SOFT_DECLARATIONS	at91_pio_t *pio	= (at91_pio_t *) ATMEL_BASE_PIOA;
501 # else
502 #  define I2C_SOFT_DECLARATIONS
503 # endif
504 #endif
505 
506 #ifdef CONFIG_8xx
507 /* Set default value for the I2C bus speed on 8xx. In the
508  * future, we'll define these in all 8xx board config files.
509  */
510 #ifndef	CONFIG_SYS_I2C_SPEED
511 #define	CONFIG_SYS_I2C_SPEED	50000
512 #endif
513 #endif
514 
515 /*
516  * Many boards/controllers/drivers don't support an I2C slave interface so
517  * provide a default slave address for them for use in common code.  A real
518  * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
519  * support a slave interface.
520  */
521 #ifndef	CONFIG_SYS_I2C_SLAVE
522 #define	CONFIG_SYS_I2C_SLAVE	0xfe
523 #endif
524 
525 /*
526  * Initialization, must be called once on start up, may be called
527  * repeatedly to change the speed and slave addresses.
528  */
529 void i2c_init(int speed, int slaveaddr);
530 void i2c_init_board(void);
531 #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
532 void i2c_board_late_init(void);
533 #endif
534 
535 #ifdef CONFIG_SYS_I2C
536 /*
537  * i2c_get_bus_num:
538  *
539  *  Returns index of currently active I2C bus.  Zero-based.
540  */
541 unsigned int i2c_get_bus_num(void);
542 
543 /*
544  * i2c_set_bus_num:
545  *
546  *  Change the active I2C bus.  Subsequent read/write calls will
547  *  go to this one.
548  *
549  *	bus - bus index, zero based
550  *
551  *	Returns: 0 on success, not 0 on failure
552  *
553  */
554 int i2c_set_bus_num(unsigned int bus);
555 
556 /*
557  * i2c_init_all():
558  *
559  * Initializes all I2C adapters in the system. All i2c_adap structures must
560  * be initialized beforehead with function pointers and data, including
561  * speed and slaveaddr. Returns 0 on success, non-0 on failure.
562  */
563 void i2c_init_all(void);
564 
565 /*
566  * Probe the given I2C chip address.  Returns 0 if a chip responded,
567  * not 0 on failure.
568  */
569 int i2c_probe(uint8_t chip);
570 
571 /*
572  * Read/Write interface:
573  *   chip:    I2C chip address, range 0..127
574  *   addr:    Memory (register) address within the chip
575  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
576  *              memories, 0 for register type devices with only one
577  *              register)
578  *   buffer:  Where to read/write the data
579  *   len:     How many bytes to read/write
580  *
581  *   Returns: 0 on success, not 0 on failure
582  */
583 int i2c_read(uint8_t chip, unsigned int addr, int alen,
584 				uint8_t *buffer, int len);
585 
586 int i2c_write(uint8_t chip, unsigned int addr, int alen,
587 				uint8_t *buffer, int len);
588 
589 /*
590  * Utility routines to read/write registers.
591  */
592 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
593 
594 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
595 
596 /*
597  * i2c_set_bus_speed:
598  *
599  *  Change the speed of the active I2C bus
600  *
601  *	speed - bus speed in Hz
602  *
603  *	Returns: new bus speed
604  *
605  */
606 unsigned int i2c_set_bus_speed(unsigned int speed);
607 
608 /*
609  * i2c_get_bus_speed:
610  *
611  *  Returns speed of currently active I2C bus in Hz
612  */
613 
614 unsigned int i2c_get_bus_speed(void);
615 
616 /*
617  * i2c_reloc_fixup:
618  *
619  * Adjusts I2C pointers after U-Boot is relocated to DRAM
620  */
621 void i2c_reloc_fixup(void);
622 #if defined(CONFIG_SYS_I2C_SOFT)
623 void i2c_soft_init(void);
624 void i2c_soft_active(void);
625 void i2c_soft_tristate(void);
626 int i2c_soft_read(void);
627 void i2c_soft_sda(int bit);
628 void i2c_soft_scl(int bit);
629 void i2c_soft_delay(void);
630 #endif
631 #else
632 
633 /*
634  * Probe the given I2C chip address.  Returns 0 if a chip responded,
635  * not 0 on failure.
636  */
637 int i2c_probe(uchar chip);
638 
639 /*
640  * Read/Write interface:
641  *   chip:    I2C chip address, range 0..127
642  *   addr:    Memory (register) address within the chip
643  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
644  *              memories, 0 for register type devices with only one
645  *              register)
646  *   buffer:  Where to read/write the data
647  *   len:     How many bytes to read/write
648  *
649  *   Returns: 0 on success, not 0 on failure
650  */
651 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
652 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
653 
654 /*
655  * Utility routines to read/write registers.
656  */
657 static inline u8 i2c_reg_read(u8 addr, u8 reg)
658 {
659 	u8 buf;
660 
661 #ifdef CONFIG_8xx
662 	/* MPC8xx needs this.  Maybe one day we can get rid of it. */
663 	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
664 #endif
665 
666 #ifdef DEBUG
667 	printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
668 #endif
669 
670 	i2c_read(addr, reg, 1, &buf, 1);
671 
672 	return buf;
673 }
674 
675 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
676 {
677 #ifdef CONFIG_8xx
678 	/* MPC8xx needs this.  Maybe one day we can get rid of it. */
679 	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
680 #endif
681 
682 #ifdef DEBUG
683 	printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
684 	       __func__, addr, reg, val);
685 #endif
686 
687 	i2c_write(addr, reg, 1, &val, 1);
688 }
689 
690 /*
691  * Functions for setting the current I2C bus and its speed
692  */
693 
694 /*
695  * i2c_set_bus_num:
696  *
697  *  Change the active I2C bus.  Subsequent read/write calls will
698  *  go to this one.
699  *
700  *	bus - bus index, zero based
701  *
702  *	Returns: 0 on success, not 0 on failure
703  *
704  */
705 int i2c_set_bus_num(unsigned int bus);
706 
707 /*
708  * i2c_get_bus_num:
709  *
710  *  Returns index of currently active I2C bus.  Zero-based.
711  */
712 
713 unsigned int i2c_get_bus_num(void);
714 
715 /*
716  * i2c_set_bus_speed:
717  *
718  *  Change the speed of the active I2C bus
719  *
720  *	speed - bus speed in Hz
721  *
722  *	Returns: 0 on success, not 0 on failure
723  *
724  */
725 int i2c_set_bus_speed(unsigned int);
726 
727 /*
728  * i2c_get_bus_speed:
729  *
730  *  Returns speed of currently active I2C bus in Hz
731  */
732 
733 unsigned int i2c_get_bus_speed(void);
734 #endif /* CONFIG_SYS_I2C */
735 
736 /*
737  * only for backwardcompatibility, should go away if we switched
738  * completely to new multibus support.
739  */
740 #if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)
741 # if !defined(CONFIG_SYS_MAX_I2C_BUS)
742 #  define CONFIG_SYS_MAX_I2C_BUS		2
743 # endif
744 # define I2C_MULTI_BUS				1
745 #else
746 # define CONFIG_SYS_MAX_I2C_BUS		1
747 # define I2C_MULTI_BUS				0
748 #endif
749 
750 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
751 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
752 static inline unsigned int I2C_GET_BUS(void)
753 {
754 	return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
755 }
756 
757 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
758 static inline void I2C_SET_BUS(unsigned int bus)
759 {
760 	if (I2C_MULTI_BUS)
761 		i2c_set_bus_num(bus);
762 }
763 
764 /* Multi I2C definitions */
765 enum {
766 	I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
767 	I2C_8, I2C_9, I2C_10,
768 };
769 
770 /* Multi I2C busses handling */
771 #ifdef CONFIG_SOFT_I2C_MULTI_BUS
772 extern int get_multi_scl_pin(void);
773 extern int get_multi_sda_pin(void);
774 extern int multi_i2c_init(void);
775 #endif
776 
777 /**
778  * Get FDT values for i2c bus.
779  *
780  * @param blob  Device tree blbo
781  * @return the number of I2C bus
782  */
783 void board_i2c_init(const void *blob);
784 
785 /**
786  * Find the I2C bus number by given a FDT I2C node.
787  *
788  * @param blob  Device tree blbo
789  * @param node  FDT I2C node to find
790  * @return the number of I2C bus (zero based), or -1 on error
791  */
792 int i2c_get_bus_num_fdt(int node);
793 
794 /**
795  * Reset the I2C bus represented by the given a FDT I2C node.
796  *
797  * @param blob  Device tree blbo
798  * @param node  FDT I2C node to find
799  * @return 0 if port was reset, -1 if not found
800  */
801 int i2c_reset_port_fdt(const void *blob, int node);
802 
803 #endif /* !CONFIG_DM_I2C */
804 
805 #endif	/* _I2C_H_ */
806