xref: /openbmc/u-boot/include/i2c.h (revision 60570df1)
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 enum dm_i2c_chip_flags {
29 	DM_I2C_CHIP_10BIT	= 1 << 0, /* Use 10-bit addressing */
30 	DM_I2C_CHIP_RD_ADDRESS	= 1 << 1, /* Send address for each read byte */
31 	DM_I2C_CHIP_WR_ADDRESS	= 1 << 2, /* Send address for each write byte */
32 };
33 
34 struct udevice;
35 /**
36  * struct dm_i2c_chip - information about an i2c chip
37  *
38  * An I2C chip is a device on the I2C bus. It sits at a particular address
39  * and normally supports 7-bit or 10-bit addressing.
40  *
41  * To obtain this structure, use dev_get_parent_platdata(dev) where dev is
42  * the chip to examine.
43  *
44  * @chip_addr:	Chip address on bus
45  * @offset_len: Length of offset in bytes. A single byte offset can
46  *		represent up to 256 bytes. A value larger than 1 may be
47  *		needed for larger devices.
48  * @flags:	Flags for this chip (dm_i2c_chip_flags)
49  * @emul: Emulator for this chip address (only used for emulation)
50  */
51 struct dm_i2c_chip {
52 	uint chip_addr;
53 	uint offset_len;
54 	uint flags;
55 #ifdef CONFIG_SANDBOX
56 	struct udevice *emul;
57 	bool test_mode;
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 dev_get_uclass_priv(bus) where bus is the
69  * I2C 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  * dm_i2c_reg_read() - Read a value from an I2C register
129  *
130  * This reads a single value from the given address in an I2C chip
131  *
132  * @addr:	Address to read from
133  * @return value read, or -ve on error
134  */
135 int dm_i2c_reg_read(struct udevice *dev, uint offset);
136 
137 /**
138  * dm_i2c_reg_write() - Write a value to an I2C register
139  *
140  * This writes a single value to the given address in an I2C chip
141  *
142  * @addr:	Address to write to
143  * @val:	Value to write (normally a byte)
144  * @return 0 on success, -ve on error
145  */
146 int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
147 
148 /**
149  * dm_i2c_set_bus_speed() - set the speed of a bus
150  *
151  * @bus:	Bus to adjust
152  * @speed:	Requested speed in Hz
153  * @return 0 if OK, -EINVAL for invalid values
154  */
155 int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
156 
157 /**
158  * dm_i2c_get_bus_speed() - get the speed of a bus
159  *
160  * @bus:	Bus to check
161  * @return speed of selected I2C bus in Hz, -ve on error
162  */
163 int dm_i2c_get_bus_speed(struct udevice *bus);
164 
165 /**
166  * i2c_set_chip_flags() - set flags for a chip
167  *
168  * Typically addresses are 7 bits, but for 10-bit addresses you should set
169  * flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
170  *
171  * @dev:	Chip to adjust
172  * @flags:	New flags
173  * @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
174  */
175 int i2c_set_chip_flags(struct udevice *dev, uint flags);
176 
177 /**
178  * i2c_get_chip_flags() - get flags for a chip
179  *
180  * @dev:	Chip to check
181  * @flagsp:	Place to put flags
182  * @return 0 if OK, other -ve value on error
183  */
184 int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
185 
186 /**
187  * i2c_set_offset_len() - set the offset length for a chip
188  *
189  * The offset used to access a chip may be up to 4 bytes long. Typically it
190  * is only 1 byte, which is enough for chips with 256 bytes of memory or
191  * registers. The default value is 1, but you can call this function to
192  * change it.
193  *
194  * @offset_len:	New offset length value (typically 1 or 2)
195  */
196 
197 int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
198 /**
199  * i2c_deblock() - recover a bus that is in an unknown state
200  *
201  * See the deblock() method in 'struct dm_i2c_ops' for full information
202  *
203  * @bus:	Bus to recover
204  * @return 0 if OK, -ve on error
205  */
206 int i2c_deblock(struct udevice *bus);
207 
208 #ifdef CONFIG_DM_I2C_COMPAT
209 /**
210  * i2c_probe() - Compatibility function for driver model
211  *
212  * Calls dm_i2c_probe() on the current bus
213  */
214 int i2c_probe(uint8_t chip_addr);
215 
216 /**
217  * i2c_read() - Compatibility function for driver model
218  *
219  * Calls dm_i2c_read() with the device corresponding to @chip_addr, and offset
220  * set to @addr. @alen must match the current setting for the device.
221  */
222 int i2c_read(uint8_t chip_addr, unsigned int addr, int alen, uint8_t *buffer,
223 	     int len);
224 
225 /**
226  * i2c_write() - Compatibility function for driver model
227  *
228  * Calls dm_i2c_write() with the device corresponding to @chip_addr, and offset
229  * set to @addr. @alen must match the current setting for the device.
230  */
231 int i2c_write(uint8_t chip_addr, unsigned int addr, int alen, uint8_t *buffer,
232 	      int len);
233 
234 /**
235  * i2c_get_bus_num_fdt() - Compatibility function for driver model
236  *
237  * @return the bus number associated with the given device tree node
238  */
239 int i2c_get_bus_num_fdt(int node);
240 
241 /**
242  * i2c_get_bus_num() - Compatibility function for driver model
243  *
244  * @return the 'current' bus number
245  */
246 unsigned int i2c_get_bus_num(void);
247 
248 /**
249  * i2c_set_bus_num() - Compatibility function for driver model
250  *
251  * Sets the 'current' bus
252  */
253 int i2c_set_bus_num(unsigned int bus);
254 
255 static inline void I2C_SET_BUS(unsigned int bus)
256 {
257 	i2c_set_bus_num(bus);
258 }
259 
260 static inline unsigned int I2C_GET_BUS(void)
261 {
262 	return i2c_get_bus_num();
263 }
264 
265 /**
266  * i2c_init() - Compatibility function for driver model
267  *
268  * This function does nothing.
269  */
270 void i2c_init(int speed, int slaveaddr);
271 
272 /**
273  * board_i2c_init() - Compatibility function for driver model
274  *
275  * @param blob  Device tree blbo
276  * @return the number of I2C bus
277  */
278 void board_i2c_init(const void *blob);
279 
280 #endif
281 
282 /*
283  * Not all of these flags are implemented in the U-Boot API
284  */
285 enum dm_i2c_msg_flags {
286 	I2C_M_TEN		= 0x0010, /* ten-bit chip address */
287 	I2C_M_RD		= 0x0001, /* read data, from slave to master */
288 	I2C_M_STOP		= 0x8000, /* send stop after this message */
289 	I2C_M_NOSTART		= 0x4000, /* no start before this message */
290 	I2C_M_REV_DIR_ADDR	= 0x2000, /* invert polarity of R/W bit */
291 	I2C_M_IGNORE_NAK	= 0x1000, /* continue after NAK */
292 	I2C_M_NO_RD_ACK		= 0x0800, /* skip the Ack bit on reads */
293 	I2C_M_RECV_LEN		= 0x0400, /* length is first received byte */
294 };
295 
296 /**
297  * struct i2c_msg - an I2C message
298  *
299  * @addr:	Slave address
300  * @flags:	Flags (see enum dm_i2c_msg_flags)
301  * @len:	Length of buffer in bytes, may be 0 for a probe
302  * @buf:	Buffer to send/receive, or NULL if no data
303  */
304 struct i2c_msg {
305 	uint addr;
306 	uint flags;
307 	uint len;
308 	u8 *buf;
309 };
310 
311 /**
312  * struct i2c_msg_list - a list of I2C messages
313  *
314  * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
315  * appropriate in U-Boot.
316  *
317  * @msg:	Pointer to i2c_msg array
318  * @nmsgs:	Number of elements in the array
319  */
320 struct i2c_msg_list {
321 	struct i2c_msg *msgs;
322 	uint nmsgs;
323 };
324 
325 /**
326  * struct dm_i2c_ops - driver operations for I2C uclass
327  *
328  * Drivers should support these operations unless otherwise noted. These
329  * operations are intended to be used by uclass code, not directly from
330  * other code.
331  */
332 struct dm_i2c_ops {
333 	/**
334 	 * xfer() - transfer a list of I2C messages
335 	 *
336 	 * @bus:	Bus to read from
337 	 * @msg:	List of messages to transfer
338 	 * @nmsgs:	Number of messages in the list
339 	 * @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
340 	 *	-ECOMM if the speed cannot be supported, -EPROTO if the chip
341 	 *	flags cannot be supported, other -ve value on some other error
342 	 */
343 	int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
344 
345 	/**
346 	 * probe_chip() - probe for the presense of a chip address
347 	 *
348 	 * This function is optional. If omitted, the uclass will send a zero
349 	 * length message instead.
350 	 *
351 	 * @bus:	Bus to probe
352 	 * @chip_addr:	Chip address to probe
353 	 * @chip_flags:	Probe flags (enum dm_i2c_chip_flags)
354 	 * @return 0 if chip was found, -EREMOTEIO if not, -ENOSYS to fall back
355 	 * to default probem other -ve value on error
356 	 */
357 	int (*probe_chip)(struct udevice *bus, uint chip_addr, uint chip_flags);
358 
359 	/**
360 	 * set_bus_speed() - set the speed of a bus (optional)
361 	 *
362 	 * The bus speed value will be updated by the uclass if this function
363 	 * does not return an error. This method is optional - if it is not
364 	 * provided then the driver can read the speed from
365 	 * dev_get_uclass_priv(bus)->speed_hz
366 	 *
367 	 * @bus:	Bus to adjust
368 	 * @speed:	Requested speed in Hz
369 	 * @return 0 if OK, -EINVAL for invalid values
370 	 */
371 	int (*set_bus_speed)(struct udevice *bus, unsigned int speed);
372 
373 	/**
374 	 * get_bus_speed() - get the speed of a bus (optional)
375 	 *
376 	 * Normally this can be provided by the uclass, but if you want your
377 	 * driver to check the bus speed by looking at the hardware, you can
378 	 * implement that here. This method is optional. This method would
379 	 * normally be expected to return dev_get_uclass_priv(bus)->speed_hz.
380 	 *
381 	 * @bus:	Bus to check
382 	 * @return speed of selected I2C bus in Hz, -ve on error
383 	 */
384 	int (*get_bus_speed)(struct udevice *bus);
385 
386 	/**
387 	 * set_flags() - set the flags for a chip (optional)
388 	 *
389 	 * This is generally implemented by the uclass, but drivers can
390 	 * check the value to ensure that unsupported options are not used.
391 	 * This method is optional. If provided, this method will always be
392 	 * called when the flags change.
393 	 *
394 	 * @dev:	Chip to adjust
395 	 * @flags:	New flags value
396 	 * @return 0 if OK, -EINVAL if value is unsupported
397 	 */
398 	int (*set_flags)(struct udevice *dev, uint flags);
399 
400 	/**
401 	 * deblock() - recover a bus that is in an unknown state
402 	 *
403 	 * I2C is a synchronous protocol and resets of the processor in the
404 	 * middle of an access can block the I2C Bus until a powerdown of
405 	 * the full unit is done. This is because slaves can be stuck
406 	 * waiting for addition bus transitions for a transaction that will
407 	 * never complete. Resetting the I2C master does not help. The only
408 	 * way is to force the bus through a series of transitions to make
409 	 * sure that all slaves are done with the transaction. This method
410 	 * performs this 'deblocking' if support by the driver.
411 	 *
412 	 * This method is optional.
413 	 */
414 	int (*deblock)(struct udevice *bus);
415 };
416 
417 #define i2c_get_ops(dev)	((struct dm_i2c_ops *)(dev)->driver->ops)
418 
419 /**
420  * i2c_get_chip() - get a device to use to access a chip on a bus
421  *
422  * This returns the device for the given chip address. The device can then
423  * be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc.
424  *
425  * @bus:	Bus to examine
426  * @chip_addr:	Chip address for the new device
427  * @offset_len:	Length of a register offset in bytes (normally 1)
428  * @devp:	Returns pointer to new device if found or -ENODEV if not
429  *		found
430  */
431 int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
432 		 struct udevice **devp);
433 
434 /**
435  * i2c_get_chip() - get a device to use to access a chip on a bus number
436  *
437  * This returns the device for the given chip address on a particular bus
438  * number.
439  *
440  * @busnum:	Bus number to examine
441  * @chip_addr:	Chip address for the new device
442  * @offset_len:	Length of a register offset in bytes (normally 1)
443  * @devp:	Returns pointer to new device if found or -ENODEV if not
444  *		found
445  */
446 int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
447 			    struct udevice **devp);
448 
449 /**
450  * i2c_chip_ofdata_to_platdata() - Decode standard I2C platform data
451  *
452  * This decodes the chip address from a device tree node and puts it into
453  * its dm_i2c_chip structure. This should be called in your driver's
454  * ofdata_to_platdata() method.
455  *
456  * @blob:	Device tree blob
457  * @node:	Node offset to read from
458  * @spi:	Place to put the decoded information
459  */
460 int i2c_chip_ofdata_to_platdata(const void *blob, int node,
461 				struct dm_i2c_chip *chip);
462 
463 #ifndef CONFIG_DM_I2C
464 
465 /*
466  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
467  *
468  * The implementation MUST NOT use static or global variables if the
469  * I2C routines are used to read SDRAM configuration information
470  * because this is done before the memories are initialized. Limited
471  * use of stack-based variables are OK (the initial stack size is
472  * limited).
473  *
474  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
475  */
476 
477 /*
478  * Configuration items.
479  */
480 #define I2C_RXTX_LEN	128	/* maximum tx/rx buffer length */
481 
482 #if !defined(CONFIG_SYS_I2C_MAX_HOPS)
483 /* no muxes used bus = i2c adapters */
484 #define CONFIG_SYS_I2C_DIRECT_BUS	1
485 #define CONFIG_SYS_I2C_MAX_HOPS		0
486 #define CONFIG_SYS_NUM_I2C_BUSES	ll_entry_count(struct i2c_adapter, i2c)
487 #else
488 /* we use i2c muxes */
489 #undef CONFIG_SYS_I2C_DIRECT_BUS
490 #endif
491 
492 /* define the I2C bus number for RTC and DTT if not already done */
493 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
494 #define CONFIG_SYS_RTC_BUS_NUM		0
495 #endif
496 #if !defined(CONFIG_SYS_DTT_BUS_NUM)
497 #define CONFIG_SYS_DTT_BUS_NUM		0
498 #endif
499 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
500 #define CONFIG_SYS_SPD_BUS_NUM		0
501 #endif
502 
503 struct i2c_adapter {
504 	void		(*init)(struct i2c_adapter *adap, int speed,
505 				int slaveaddr);
506 	int		(*probe)(struct i2c_adapter *adap, uint8_t chip);
507 	int		(*read)(struct i2c_adapter *adap, uint8_t chip,
508 				uint addr, int alen, uint8_t *buffer,
509 				int len);
510 	int		(*write)(struct i2c_adapter *adap, uint8_t chip,
511 				uint addr, int alen, uint8_t *buffer,
512 				int len);
513 	uint		(*set_bus_speed)(struct i2c_adapter *adap,
514 				uint speed);
515 	int		speed;
516 	int		waitdelay;
517 	int		slaveaddr;
518 	int		init_done;
519 	int		hwadapnr;
520 	char		*name;
521 };
522 
523 #define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
524 		_set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
525 	{ \
526 		.init		=	_init, \
527 		.probe		=	_probe, \
528 		.read		=	_read, \
529 		.write		=	_write, \
530 		.set_bus_speed	=	_set_speed, \
531 		.speed		=	_speed, \
532 		.slaveaddr	=	_slaveaddr, \
533 		.init_done	=	0, \
534 		.hwadapnr	=	_hwadapnr, \
535 		.name		=	#_name \
536 };
537 
538 #define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
539 			_set_speed, _speed, _slaveaddr, _hwadapnr) \
540 	ll_entry_declare(struct i2c_adapter, _name, i2c) = \
541 	U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
542 		 _set_speed, _speed, _slaveaddr, _hwadapnr, _name);
543 
544 struct i2c_adapter *i2c_get_adapter(int index);
545 
546 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
547 struct i2c_mux {
548 	int	id;
549 	char	name[16];
550 };
551 
552 struct i2c_next_hop {
553 	struct i2c_mux		mux;
554 	uint8_t		chip;
555 	uint8_t		channel;
556 };
557 
558 struct i2c_bus_hose {
559 	int	adapter;
560 	struct i2c_next_hop	next_hop[CONFIG_SYS_I2C_MAX_HOPS];
561 };
562 #define I2C_NULL_HOP	{{-1, ""}, 0, 0}
563 extern struct i2c_bus_hose	i2c_bus[];
564 
565 #define I2C_ADAPTER(bus)	i2c_bus[bus].adapter
566 #else
567 #define I2C_ADAPTER(bus)	bus
568 #endif
569 #define	I2C_BUS			gd->cur_i2c_bus
570 
571 #define	I2C_ADAP_NR(bus)	i2c_get_adapter(I2C_ADAPTER(bus))
572 #define	I2C_ADAP		I2C_ADAP_NR(gd->cur_i2c_bus)
573 #define I2C_ADAP_HWNR		(I2C_ADAP->hwadapnr)
574 
575 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
576 #define I2C_MUX_PCA9540_ID	1
577 #define I2C_MUX_PCA9540		{I2C_MUX_PCA9540_ID, "PCA9540B"}
578 #define I2C_MUX_PCA9542_ID	2
579 #define I2C_MUX_PCA9542		{I2C_MUX_PCA9542_ID, "PCA9542A"}
580 #define I2C_MUX_PCA9544_ID	3
581 #define I2C_MUX_PCA9544		{I2C_MUX_PCA9544_ID, "PCA9544A"}
582 #define I2C_MUX_PCA9547_ID	4
583 #define I2C_MUX_PCA9547		{I2C_MUX_PCA9547_ID, "PCA9547A"}
584 #define I2C_MUX_PCA9548_ID	5
585 #define I2C_MUX_PCA9548		{I2C_MUX_PCA9548_ID, "PCA9548"}
586 #endif
587 
588 #ifndef I2C_SOFT_DECLARATIONS
589 # if defined(CONFIG_MPC8260)
590 #  define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
591 # elif defined(CONFIG_8xx)
592 #  define I2C_SOFT_DECLARATIONS	volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
593 
594 # elif (defined(CONFIG_AT91RM9200) || \
595 	defined(CONFIG_AT91SAM9260) ||  defined(CONFIG_AT91SAM9261) || \
596 	defined(CONFIG_AT91SAM9263))
597 #  define I2C_SOFT_DECLARATIONS	at91_pio_t *pio	= (at91_pio_t *) ATMEL_BASE_PIOA;
598 # else
599 #  define I2C_SOFT_DECLARATIONS
600 # endif
601 #endif
602 
603 #ifdef CONFIG_8xx
604 /* Set default value for the I2C bus speed on 8xx. In the
605  * future, we'll define these in all 8xx board config files.
606  */
607 #ifndef	CONFIG_SYS_I2C_SPEED
608 #define	CONFIG_SYS_I2C_SPEED	50000
609 #endif
610 #endif
611 
612 /*
613  * Many boards/controllers/drivers don't support an I2C slave interface so
614  * provide a default slave address for them for use in common code.  A real
615  * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
616  * support a slave interface.
617  */
618 #ifndef	CONFIG_SYS_I2C_SLAVE
619 #define	CONFIG_SYS_I2C_SLAVE	0xfe
620 #endif
621 
622 /*
623  * Initialization, must be called once on start up, may be called
624  * repeatedly to change the speed and slave addresses.
625  */
626 void i2c_init(int speed, int slaveaddr);
627 void i2c_init_board(void);
628 #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
629 void i2c_board_late_init(void);
630 #endif
631 
632 #ifdef CONFIG_SYS_I2C
633 /*
634  * i2c_get_bus_num:
635  *
636  *  Returns index of currently active I2C bus.  Zero-based.
637  */
638 unsigned int i2c_get_bus_num(void);
639 
640 /*
641  * i2c_set_bus_num:
642  *
643  *  Change the active I2C bus.  Subsequent read/write calls will
644  *  go to this one.
645  *
646  *	bus - bus index, zero based
647  *
648  *	Returns: 0 on success, not 0 on failure
649  *
650  */
651 int i2c_set_bus_num(unsigned int bus);
652 
653 /*
654  * i2c_init_all():
655  *
656  * Initializes all I2C adapters in the system. All i2c_adap structures must
657  * be initialized beforehead with function pointers and data, including
658  * speed and slaveaddr. Returns 0 on success, non-0 on failure.
659  */
660 void i2c_init_all(void);
661 
662 /*
663  * Probe the given I2C chip address.  Returns 0 if a chip responded,
664  * not 0 on failure.
665  */
666 int i2c_probe(uint8_t chip);
667 
668 /*
669  * Read/Write interface:
670  *   chip:    I2C chip address, range 0..127
671  *   addr:    Memory (register) address within the chip
672  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
673  *              memories, 0 for register type devices with only one
674  *              register)
675  *   buffer:  Where to read/write the data
676  *   len:     How many bytes to read/write
677  *
678  *   Returns: 0 on success, not 0 on failure
679  */
680 int i2c_read(uint8_t chip, unsigned int addr, int alen,
681 				uint8_t *buffer, int len);
682 
683 int i2c_write(uint8_t chip, unsigned int addr, int alen,
684 				uint8_t *buffer, int len);
685 
686 /*
687  * Utility routines to read/write registers.
688  */
689 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
690 
691 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
692 
693 /*
694  * i2c_set_bus_speed:
695  *
696  *  Change the speed of the active I2C bus
697  *
698  *	speed - bus speed in Hz
699  *
700  *	Returns: new bus speed
701  *
702  */
703 unsigned int i2c_set_bus_speed(unsigned int speed);
704 
705 /*
706  * i2c_get_bus_speed:
707  *
708  *  Returns speed of currently active I2C bus in Hz
709  */
710 
711 unsigned int i2c_get_bus_speed(void);
712 
713 /*
714  * i2c_reloc_fixup:
715  *
716  * Adjusts I2C pointers after U-Boot is relocated to DRAM
717  */
718 void i2c_reloc_fixup(void);
719 #if defined(CONFIG_SYS_I2C_SOFT)
720 void i2c_soft_init(void);
721 void i2c_soft_active(void);
722 void i2c_soft_tristate(void);
723 int i2c_soft_read(void);
724 void i2c_soft_sda(int bit);
725 void i2c_soft_scl(int bit);
726 void i2c_soft_delay(void);
727 #endif
728 #else
729 
730 /*
731  * Probe the given I2C chip address.  Returns 0 if a chip responded,
732  * not 0 on failure.
733  */
734 int i2c_probe(uchar chip);
735 
736 /*
737  * Read/Write interface:
738  *   chip:    I2C chip address, range 0..127
739  *   addr:    Memory (register) address within the chip
740  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
741  *              memories, 0 for register type devices with only one
742  *              register)
743  *   buffer:  Where to read/write the data
744  *   len:     How many bytes to read/write
745  *
746  *   Returns: 0 on success, not 0 on failure
747  */
748 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
749 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
750 
751 /*
752  * Utility routines to read/write registers.
753  */
754 static inline u8 i2c_reg_read(u8 addr, u8 reg)
755 {
756 	u8 buf;
757 
758 #ifdef CONFIG_8xx
759 	/* MPC8xx needs this.  Maybe one day we can get rid of it. */
760 	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
761 #endif
762 
763 #ifdef DEBUG
764 	printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
765 #endif
766 
767 	i2c_read(addr, reg, 1, &buf, 1);
768 
769 	return buf;
770 }
771 
772 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
773 {
774 #ifdef CONFIG_8xx
775 	/* MPC8xx needs this.  Maybe one day we can get rid of it. */
776 	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
777 #endif
778 
779 #ifdef DEBUG
780 	printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
781 	       __func__, addr, reg, val);
782 #endif
783 
784 	i2c_write(addr, reg, 1, &val, 1);
785 }
786 
787 /*
788  * Functions for setting the current I2C bus and its speed
789  */
790 
791 /*
792  * i2c_set_bus_num:
793  *
794  *  Change the active I2C bus.  Subsequent read/write calls will
795  *  go to this one.
796  *
797  *	bus - bus index, zero based
798  *
799  *	Returns: 0 on success, not 0 on failure
800  *
801  */
802 int i2c_set_bus_num(unsigned int bus);
803 
804 /*
805  * i2c_get_bus_num:
806  *
807  *  Returns index of currently active I2C bus.  Zero-based.
808  */
809 
810 unsigned int i2c_get_bus_num(void);
811 
812 /*
813  * i2c_set_bus_speed:
814  *
815  *  Change the speed of the active I2C bus
816  *
817  *	speed - bus speed in Hz
818  *
819  *	Returns: 0 on success, not 0 on failure
820  *
821  */
822 int i2c_set_bus_speed(unsigned int);
823 
824 /*
825  * i2c_get_bus_speed:
826  *
827  *  Returns speed of currently active I2C bus in Hz
828  */
829 
830 unsigned int i2c_get_bus_speed(void);
831 #endif /* CONFIG_SYS_I2C */
832 
833 /*
834  * only for backwardcompatibility, should go away if we switched
835  * completely to new multibus support.
836  */
837 #if defined(CONFIG_SYS_I2C) || defined(CONFIG_I2C_MULTI_BUS)
838 # if !defined(CONFIG_SYS_MAX_I2C_BUS)
839 #  define CONFIG_SYS_MAX_I2C_BUS		2
840 # endif
841 # define I2C_MULTI_BUS				1
842 #else
843 # define CONFIG_SYS_MAX_I2C_BUS		1
844 # define I2C_MULTI_BUS				0
845 #endif
846 
847 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
848 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
849 static inline unsigned int I2C_GET_BUS(void)
850 {
851 	return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
852 }
853 
854 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
855 static inline void I2C_SET_BUS(unsigned int bus)
856 {
857 	if (I2C_MULTI_BUS)
858 		i2c_set_bus_num(bus);
859 }
860 
861 /* Multi I2C definitions */
862 enum {
863 	I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
864 	I2C_8, I2C_9, I2C_10,
865 };
866 
867 /* Multi I2C busses handling */
868 #ifdef CONFIG_SOFT_I2C_MULTI_BUS
869 extern int get_multi_scl_pin(void);
870 extern int get_multi_sda_pin(void);
871 extern int multi_i2c_init(void);
872 #endif
873 
874 /**
875  * Get FDT values for i2c bus.
876  *
877  * @param blob  Device tree blbo
878  * @return the number of I2C bus
879  */
880 void board_i2c_init(const void *blob);
881 
882 /**
883  * Find the I2C bus number by given a FDT I2C node.
884  *
885  * @param blob  Device tree blbo
886  * @param node  FDT I2C node to find
887  * @return the number of I2C bus (zero based), or -1 on error
888  */
889 int i2c_get_bus_num_fdt(int node);
890 
891 /**
892  * Reset the I2C bus represented by the given a FDT I2C node.
893  *
894  * @param blob  Device tree blbo
895  * @param node  FDT I2C node to find
896  * @return 0 if port was reset, -1 if not found
897  */
898 int i2c_reset_port_fdt(const void *blob, int node);
899 
900 #endif /* !CONFIG_DM_I2C */
901 
902 #endif	/* _I2C_H_ */
903