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 #include <linker_lists.h>
20 
21 /*
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.
27  */
28 
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 */
33 };
34 
35 /** enum i2c_speed_mode - standard I2C speed modes */
36 enum i2c_speed_mode {
37 	IC_SPEED_MODE_STANDARD,
38 	IC_SPEED_MODE_FAST,
39 	IC_SPEED_MODE_FAST_PLUS,
40 	IC_SPEED_MODE_HIGH,
41 	IC_SPEED_MODE_FAST_ULTRA,
42 
43 	IC_SPEED_MODE_COUNT,
44 };
45 
46 /** enum i2c_speed_rate - standard I2C speeds in Hz */
47 enum i2c_speed_rate {
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,
53 };
54 
55 /** enum i2c_address_mode - available address modes */
56 enum i2c_address_mode {
57 	I2C_MODE_7_BIT,
58 	I2C_MODE_10_BIT
59 };
60 
61 /** enum i2c_device_t - Types of I2C devices, used for compatible strings */
62 enum i2c_device_t {
63 	I2C_DEVICE_GENERIC,
64 	I2C_DEVICE_HID_OVER_I2C,
65 };
66 
67 struct udevice;
68 /**
69  * struct dm_i2c_chip - information about an i2c chip
70  *
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.
73  *
74  * To obtain this structure, use dev_get_parent_plat(dev) where dev is
75  * the chip to examine.
76  *
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
91  *			   0x2d.
92  *			   A real world example is the Atmel AT24C04. It's
93  *			   datasheet explains it's usage of this addressing
94  *			   mode.
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.
98  */
99 struct dm_i2c_chip {
100 	uint chip_addr;
101 	uint offset_len;
102 	uint flags;
103 	uint chip_addr_offset_mask;
104 #ifdef CONFIG_SANDBOX
105 	struct udevice *emul;
106 	bool test_mode;
107 	int emul_idx;
108 #endif
109 };
110 
111 /**
112  * struct dm_i2c_bus- information about an i2c bus
113  *
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
116  * or 400KHz).
117  *
118  * To obtain this structure, use dev_get_uclass_priv(bus) where bus is the
119  * I2C bus udevice.
120  *
121  * @speed_hz: Bus speed in hertz (typically 100000)
122  * @max_transaction_bytes: Maximal size of single I2C transfer
123  */
124 struct dm_i2c_bus {
125 	int speed_hz;
126 	int max_transaction_bytes;
127 };
128 
129 /*
130  * Not all of these flags are implemented in the U-Boot API
131  */
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 */
141 };
142 
143 /**
144  * struct i2c_msg - an I2C message
145  *
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
150  */
151 struct i2c_msg {
152 	uint addr;
153 	uint flags;
154 	uint len;
155 	u8 *buf;
156 };
157 
158 /**
159  * struct i2c_msg_list - a list of I2C messages
160  *
161  * This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
162  * appropriate in U-Boot.
163  *
164  * @msg:	Pointer to i2c_msg array
165  * @nmsgs:	Number of elements in the array
166  */
167 struct i2c_msg_list {
168 	struct i2c_msg *msgs;
169 	uint nmsgs;
170 };
171 
172 /**
173  * dm_i2c_read() - read bytes from an I2C chip
174  *
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>).
178  *
179  * To set the address length of a devce use i2c_set_addr_len(). It
180  * defaults to 1.
181  *
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
186  *
187  * Return: 0 on success, -ve on failure
188  */
189 int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len);
190 
191 /**
192  * dm_i2c_write() - write bytes to an I2C chip
193  *
194  * See notes for dm_i2c_read() above.
195  *
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
200  *
201  * Return: 0 on success, -ve on failure
202  */
203 int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
204 		 int len);
205 
206 /**
207  * dm_i2c_probe() - probe a particular chip address
208  *
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.
212  *
213  * @bus:	Bus to probe
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
218  */
219 int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
220 		 struct udevice **devp);
221 
222 /**
223  * dm_i2c_reg_read() - Read a value from an I2C register
224  *
225  * This reads a single value from the given address in an I2C chip
226  *
227  * @dev:	Device to use for transfer
228  * @addr:	Address to read from
229  * Return: value read, or -ve on error
230  */
231 int dm_i2c_reg_read(struct udevice *dev, uint offset);
232 
233 /**
234  * dm_i2c_reg_write() - Write a value to an I2C register
235  *
236  * This writes a single value to the given address in an I2C chip
237  *
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
242  */
243 int dm_i2c_reg_write(struct udevice *dev, uint offset, unsigned int val);
244 
245 /**
246  * dm_i2c_reg_clrset() - Apply bitmask to an I2C register
247  *
248  * Read value, apply bitmask and write modified value back to the
249  * given address in an I2C chip
250  *
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
256  */
257 int dm_i2c_reg_clrset(struct udevice *dev, uint offset, u32 clr, u32 set);
258 
259 /**
260  * dm_i2c_xfer() - Transfer messages over I2C
261  *
262  * This transfers a raw message. It is best to use dm_i2c_reg_read/write()
263  * instead.
264  *
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
269  */
270 int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs);
271 
272 /**
273  * dm_i2c_set_bus_speed() - set the speed of a bus
274  *
275  * @bus:	Bus to adjust
276  * @speed:	Requested speed in Hz
277  * Return: 0 if OK, -EINVAL for invalid values
278  */
279 int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
280 
281 /**
282  * dm_i2c_get_bus_speed() - get the speed of a bus
283  *
284  * @bus:	Bus to check
285  * Return: speed of selected I2C bus in Hz, -ve on error
286  */
287 int dm_i2c_get_bus_speed(struct udevice *bus);
288 
289 /**
290  * i2c_set_chip_flags() - set flags for a chip
291  *
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.
294  *
295  * @dev:	Chip to adjust
296  * @flags:	New flags
297  * Return: 0 if OK, -EINVAL if value is unsupported, other -ve value on error
298  */
299 int i2c_set_chip_flags(struct udevice *dev, uint flags);
300 
301 /**
302  * i2c_get_chip_flags() - get flags for a chip
303  *
304  * @dev:	Chip to check
305  * @flagsp:	Place to put flags
306  * Return: 0 if OK, other -ve value on error
307  */
308 int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
309 
310 /**
311  * i2c_set_offset_len() - set the offset length for a chip
312  *
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
316  * change it.
317  *
318  * @offset_len:	New offset length value (typically 1 or 2)
319  */
320 int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
321 
322 /**
323  * i2c_get_offset_len() - get the offset length for a chip
324  *
325  * @return:	Current offset length value (typically 1 or 2)
326  */
327 int i2c_get_chip_offset_len(struct udevice *dev);
328 
329 /**
330  * i2c_set_chip_addr_offset_mask() - set mask of address bits usable by offset
331  *
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.
335  *
336  * @mask: The mask to be used for high offset bits within address
337  * Return: 0 if OK, other -ve value on error
338  */
339 int i2c_set_chip_addr_offset_mask(struct udevice *dev, uint mask);
340 
341 /*
342  * i2c_get_chip_addr_offset_mask() - get mask of address bits usable by offset
343  *
344  * Return: current chip addr offset mask
345  */
346 uint i2c_get_chip_addr_offset_mask(struct udevice *dev);
347 
348 /**
349  * i2c_deblock() - recover a bus that is in an unknown state
350  *
351  * See the deblock() method in 'struct dm_i2c_ops' for full information
352  *
353  * @bus:	Bus to recover
354  * Return: 0 if OK, -ve on error
355  */
356 int i2c_deblock(struct udevice *bus);
357 
358 /**
359  * i2c_deblock_gpio_loop() - recover a bus from an unknown state by toggling SDA/SCL
360  *
361  * This is the inner logic used for toggling I2C SDA/SCL lines as GPIOs
362  * for deblocking the I2C bus.
363  *
364  * @sda_pin:	SDA GPIO
365  * @scl_pin:	SCL GPIO
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
370  */
371 struct gpio_desc;
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,
374 			  unsigned int delay);
375 
376 /**
377  * struct dm_i2c_ops - driver operations for I2C uclass
378  *
379  * Drivers should support these operations unless otherwise noted. These
380  * operations are intended to be used by uclass code, not directly from
381  * other code.
382  */
383 struct dm_i2c_ops {
384 	/**
385 	 * xfer() - transfer a list of I2C messages
386 	 *
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
393 	 */
394 	int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
395 
396 	/**
397 	 * probe_chip() - probe for the presense of a chip address
398 	 *
399 	 * This function is optional. If omitted, the uclass will send a zero
400 	 * length message instead.
401 	 *
402 	 * @bus:	Bus to probe
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
407 	 */
408 	int (*probe_chip)(struct udevice *bus, uint chip_addr, uint chip_flags);
409 
410 	/**
411 	 * set_bus_speed() - set the speed of a bus (optional)
412 	 *
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
417 	 *
418 	 * @bus:	Bus to adjust
419 	 * @speed:	Requested speed in Hz
420 	 * @return 0 if OK, -EINVAL for invalid values
421 	 */
422 	int (*set_bus_speed)(struct udevice *bus, unsigned int speed);
423 
424 	/**
425 	 * get_bus_speed() - get the speed of a bus (optional)
426 	 *
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.
431 	 *
432 	 * @bus:	Bus to check
433 	 * @return speed of selected I2C bus in Hz, -ve on error
434 	 */
435 	int (*get_bus_speed)(struct udevice *bus);
436 
437 	/**
438 	 * set_flags() - set the flags for a chip (optional)
439 	 *
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.
444 	 *
445 	 * @dev:	Chip to adjust
446 	 * @flags:	New flags value
447 	 * @return 0 if OK, -EINVAL if value is unsupported
448 	 */
449 	int (*set_flags)(struct udevice *dev, uint flags);
450 
451 	/**
452 	 * deblock() - recover a bus that is in an unknown state
453 	 *
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.
462 	 *
463 	 * This method is optional.
464 	 */
465 	int (*deblock)(struct udevice *bus);
466 };
467 
468 #define i2c_get_ops(dev)	((struct dm_i2c_ops *)(dev)->driver->ops)
469 
470 /**
471  * struct i2c_mux_ops - operations for an I2C mux
472  *
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.
478  */
479 struct i2c_mux_ops {
480 	/**
481 	 * select() - select one of of I2C buses attached to a mux
482 	 *
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.
486 	 *
487 	 * @mux:	Mux device
488 	 * @bus:	I2C bus to select
489 	 * @channel:	Channel number correponding to the bus to select
490 	 * @return 0 if OK, -ve on error
491 	 */
492 	int (*select)(struct udevice *mux, struct udevice *bus, uint channel);
493 
494 	/**
495 	 * deselect() - select one of of I2C buses attached to a mux
496 	 *
497 	 * This is used to deselect the currently selected I2C bus.
498 	 *
499 	 * @mux:	Mux device
500 	 * @bus:	I2C bus to deselect
501 	 * @channel:	Channel number correponding to the bus to deselect
502 	 * @return 0 if OK, -ve on error
503 	 */
504 	int (*deselect)(struct udevice *mux, struct udevice *bus, uint channel);
505 };
506 
507 #define i2c_mux_get_ops(dev)	((struct i2c_mux_ops *)(dev)->driver->ops)
508 
509 /**
510  * i2c_get_chip() - get a device to use to access a chip on a bus
511  *
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.
514  *
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
519  *		found
520  */
521 int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
522 		 struct udevice **devp);
523 
524 /**
525  * i2c_get_chip_for_busnum() - get a device to use to access a chip on
526  *			       a bus number
527  *
528  * This returns the device for the given chip address on a particular bus
529  * number.
530  *
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
535  *		found
536  */
537 int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
538 			    struct udevice **devp);
539 
540 /**
541  * i2c_get_chip_by_phandle() - get a device to use to access a chip
542  *			       based on a phandle property pointing to it
543  *
544  * @parent: Parent device containing the phandle pointer
545  * @name:   Name of phandle property in the parent device node
546  * @devp:   Returns pointer to new device or NULL if not found
547  * Return:  0 on success, -ve on failure
548  */
549 int i2c_get_chip_by_phandle(const struct udevice *parent, const char *prop_name,
550 			    struct udevice **devp);
551 
552 /**
553  * i2c_chip_of_to_plat() - Decode standard I2C platform data
554  *
555  * This decodes the chip address from a device tree node and puts it into
556  * its dm_i2c_chip structure. This should be called in your driver's
557  * of_to_plat() method.
558  *
559  * @blob:	Device tree blob
560  * @node:	Node offset to read from
561  * @spi:	Place to put the decoded information
562  */
563 int i2c_chip_of_to_plat(struct udevice *dev, struct dm_i2c_chip *chip);
564 
565 /**
566  * i2c_dump_msgs() - Dump a list of I2C messages
567  *
568  * This may be useful for debugging.
569  *
570  * @msg:	Message list to dump
571  * @nmsgs:	Number of messages
572  */
573 void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs);
574 
575 /**
576  * i2c_emul_find() - Find an emulator for an i2c sandbox device
577  *
578  * This looks at the device's 'emul' phandle
579  *
580  * @dev: Device to find an emulator for
581  * @emulp: Returns the associated emulator, if found *
582  * Return: 0 if OK, -ENOENT or -ENODEV if not found
583  */
584 int i2c_emul_find(struct udevice *dev, struct udevice **emulp);
585 
586 /**
587  * i2c_emul_set_idx() - Set the emulator index for an i2c sandbox device
588  *
589  * With of-platdata we cannot find the emulator using the device tree, so rely
590  * on the bind() method of each i2c driver calling this function to tell us
591  * the of-platdata idx of the emulator
592  *
593  * @dev: i2c device to set the emulator for
594  * @emul_idx: of-platdata index for that emulator
595  */
596 void i2c_emul_set_idx(struct udevice *dev, int emul_idx);
597 
598 /**
599  * i2c_emul_get_device() - Find the device being emulated
600  *
601  * Given an emulator this returns the associated device
602  *
603  * @emul: Emulator for the device
604  * Return: device that @emul is emulating
605  */
606 struct udevice *i2c_emul_get_device(struct udevice *emul);
607 
608 /* ACPI operations for generic I2C devices */
609 extern struct acpi_ops i2c_acpi_ops;
610 
611 /**
612  * acpi_i2c_of_to_plat() - Read properties intended for ACPI
613  *
614  * This reads the generic I2C properties from the device tree, so that these
615  * can be used to create ACPI information for the device.
616  *
617  * See the i2c/generic-acpi.txt binding file for information about the
618  * properties.
619  *
620  * @dev: I2C device to process
621  * Return: 0 if OK, -EINVAL if acpi,hid is not present
622  */
623 int acpi_i2c_of_to_plat(struct udevice *dev);
624 
625 #ifdef CONFIG_SYS_I2C_EARLY_INIT
626 void i2c_early_init_f(void);
627 #endif
628 
629 #if !CONFIG_IS_ENABLED(DM_I2C)
630 
631 /*
632  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
633  *
634  * The implementation MUST NOT use static or global variables if the
635  * I2C routines are used to read SDRAM configuration information
636  * because this is done before the memories are initialized. Limited
637  * use of stack-based variables are OK (the initial stack size is
638  * limited).
639  *
640  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
641  */
642 
643 /*
644  * Configuration items.
645  */
646 #define I2C_RXTX_LEN	128	/* maximum tx/rx buffer length */
647 
648 /* no muxes used bus = i2c adapters */
649 #define CFG_SYS_NUM_I2C_BUSES	ll_entry_count(struct i2c_adapter, i2c)
650 
651 struct i2c_adapter {
652 	void		(*init)(struct i2c_adapter *adap, int speed,
653 				int slaveaddr);
654 	int		(*probe)(struct i2c_adapter *adap, uint8_t chip);
655 	int		(*read)(struct i2c_adapter *adap, uint8_t chip,
656 				uint addr, int alen, uint8_t *buffer,
657 				int len);
658 	int		(*write)(struct i2c_adapter *adap, uint8_t chip,
659 				uint addr, int alen, uint8_t *buffer,
660 				int len);
661 	uint		(*set_bus_speed)(struct i2c_adapter *adap,
662 				uint speed);
663 	int		speed;
664 	int		waitdelay;
665 	int		slaveaddr;
666 	int		init_done;
667 	int		hwadapnr;
668 	char		*name;
669 };
670 
671 #define U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
672 		_set_speed, _speed, _slaveaddr, _hwadapnr, _name) \
673 	{ \
674 		.init		=	_init, \
675 		.probe		=	_probe, \
676 		.read		=	_read, \
677 		.write		=	_write, \
678 		.set_bus_speed	=	_set_speed, \
679 		.speed		=	_speed, \
680 		.slaveaddr	=	_slaveaddr, \
681 		.init_done	=	0, \
682 		.hwadapnr	=	_hwadapnr, \
683 		.name		=	#_name \
684 };
685 
686 #define U_BOOT_I2C_ADAP_COMPLETE(_name, _init, _probe, _read, _write, \
687 			_set_speed, _speed, _slaveaddr, _hwadapnr) \
688 	ll_entry_declare(struct i2c_adapter, _name, i2c) = \
689 	U_BOOT_I2C_MKENT_COMPLETE(_init, _probe, _read, _write, \
690 		 _set_speed, _speed, _slaveaddr, _hwadapnr, _name);
691 
692 struct i2c_adapter *i2c_get_adapter(int index);
693 
694 #define I2C_ADAPTER(bus)	bus
695 #define	I2C_BUS			gd->cur_i2c_bus
696 
697 #define	I2C_ADAP_NR(bus)	i2c_get_adapter(I2C_ADAPTER(bus))
698 #define	I2C_ADAP		I2C_ADAP_NR(gd->cur_i2c_bus)
699 #define I2C_ADAP_HWNR		(I2C_ADAP->hwadapnr)
700 
701 #ifndef I2C_SOFT_DECLARATIONS
702 # if (defined(CONFIG_AT91RM9200) || \
703 	defined(CONFIG_AT91SAM9260) ||  defined(CONFIG_AT91SAM9261) || \
704 	defined(CONFIG_AT91SAM9263))
705 #  define I2C_SOFT_DECLARATIONS	at91_pio_t *pio	= (at91_pio_t *) ATMEL_BASE_PIOA;
706 # else
707 #  define I2C_SOFT_DECLARATIONS
708 # endif
709 #endif
710 
711 /*
712  * Initialization, must be called once on start up, may be called
713  * repeatedly to change the speed and slave addresses.
714  */
715 void i2c_init(int speed, int slaveaddr);
716 void i2c_init_board(void);
717 
718 #if CONFIG_IS_ENABLED(SYS_I2C_LEGACY)
719 /*
720  * i2c_get_bus_num:
721  *
722  *  Returns index of currently active I2C bus.  Zero-based.
723  */
724 unsigned int i2c_get_bus_num(void);
725 
726 /*
727  * i2c_set_bus_num:
728  *
729  *  Change the active I2C bus.  Subsequent read/write calls will
730  *  go to this one.
731  *
732  *	bus - bus index, zero based
733  *
734  *	Returns: 0 on success, not 0 on failure
735  *
736  */
737 int i2c_set_bus_num(unsigned int bus);
738 
739 /*
740  * i2c_init_all():
741  *
742  * Initializes all I2C adapters in the system. All i2c_adap structures must
743  * be initialized beforehead with function pointers and data, including
744  * speed and slaveaddr. Returns 0 on success, non-0 on failure.
745  */
746 void i2c_init_all(void);
747 
748 /*
749  * Probe the given I2C chip address.  Returns 0 if a chip responded,
750  * not 0 on failure.
751  */
752 int i2c_probe(uint8_t chip);
753 
754 /*
755  * Read/Write interface:
756  *   chip:    I2C chip address, range 0..127
757  *   addr:    Memory (register) address within the chip
758  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
759  *              memories, 0 for register type devices with only one
760  *              register)
761  *   buffer:  Where to read/write the data
762  *   len:     How many bytes to read/write
763  *
764  *   Returns: 0 on success, not 0 on failure
765  */
766 int i2c_read(uint8_t chip, unsigned int addr, int alen,
767 				uint8_t *buffer, int len);
768 
769 int i2c_write(uint8_t chip, unsigned int addr, int alen,
770 				uint8_t *buffer, int len);
771 
772 /*
773  * Utility routines to read/write registers.
774  */
775 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg);
776 
777 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val);
778 
779 /*
780  * i2c_set_bus_speed:
781  *
782  *  Change the speed of the active I2C bus
783  *
784  *	speed - bus speed in Hz
785  *
786  *	Returns: new bus speed
787  *
788  */
789 unsigned int i2c_set_bus_speed(unsigned int speed);
790 
791 /*
792  * i2c_get_bus_speed:
793  *
794  *  Returns speed of currently active I2C bus in Hz
795  */
796 
797 unsigned int i2c_get_bus_speed(void);
798 
799 #else
800 
801 /*
802  * Probe the given I2C chip address.  Returns 0 if a chip responded,
803  * not 0 on failure.
804  */
805 int i2c_probe(uchar chip);
806 
807 /*
808  * Read/Write interface:
809  *   chip:    I2C chip address, range 0..127
810  *   addr:    Memory (register) address within the chip
811  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
812  *              memories, 0 for register type devices with only one
813  *              register)
814  *   buffer:  Where to read/write the data
815  *   len:     How many bytes to read/write
816  *
817  *   Returns: 0 on success, not 0 on failure
818  */
819 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
820 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
821 
822 /*
823  * Utility routines to read/write registers.
824  */
i2c_reg_read(u8 addr,u8 reg)825 static inline u8 i2c_reg_read(u8 addr, u8 reg)
826 {
827 	u8 buf;
828 
829 #ifdef DEBUG
830 	printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
831 #endif
832 
833 	i2c_read(addr, reg, 1, &buf, 1);
834 
835 	return buf;
836 }
837 
i2c_reg_write(u8 addr,u8 reg,u8 val)838 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
839 {
840 #ifdef DEBUG
841 	printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
842 	       __func__, addr, reg, val);
843 #endif
844 
845 	i2c_write(addr, reg, 1, &val, 1);
846 }
847 
848 /*
849  * Functions for setting the current I2C bus and its speed
850  */
851 
852 /*
853  * i2c_set_bus_num:
854  *
855  *  Change the active I2C bus.  Subsequent read/write calls will
856  *  go to this one.
857  *
858  *	bus - bus index, zero based
859  *
860  *	Returns: 0 on success, not 0 on failure
861  *
862  */
863 int i2c_set_bus_num(unsigned int bus);
864 
865 /*
866  * i2c_get_bus_num:
867  *
868  *  Returns index of currently active I2C bus.  Zero-based.
869  */
870 
871 unsigned int i2c_get_bus_num(void);
872 
873 /*
874  * i2c_set_bus_speed:
875  *
876  *  Change the speed of the active I2C bus
877  *
878  *	speed - bus speed in Hz
879  *
880  *	Returns: 0 on success, not 0 on failure
881  *
882  */
883 int i2c_set_bus_speed(unsigned int);
884 
885 /*
886  * i2c_get_bus_speed:
887  *
888  *  Returns speed of currently active I2C bus in Hz
889  */
890 
891 unsigned int i2c_get_bus_speed(void);
892 #endif /* CONFIG_SYS_I2C_LEGACY */
893 
894 #endif /* !CONFIG_DM_I2C */
895 
896 #endif	/* _I2C_H_ */
897