3 * Heiko Schocher, DENX Software Engineering, hs@denx.de.
4 * Changes for multibus/multiadapter I2C support.
6 * (C) Copyright 2001, 2002
7 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
9 * SPDX-License-Identifier: GPL-2.0+
11 * This has been changed substantially by Gerald Van Baren, Custom IDEAS,
12 * vanbaren@cideas.com. It was heavily influenced by LiMon, written by
17 #ifdef CONFIG_MPC8260 /* only valid for MPC8260 */
21 #if defined(CONFIG_AVR32)
22 #include <asm/arch/portmux.h>
24 #if defined(CONFIG_AT91FAMILY)
26 #include <asm/arch/hardware.h>
27 #include <asm/arch/at91_pio.h>
28 #ifdef CONFIG_AT91_LEGACY
29 #include <asm/arch/gpio.h>
32 #ifdef CONFIG_IXP425 /* only valid for IXP425 */
33 #include <asm/arch/ixp425.h>
35 #if defined(CONFIG_MPC852T) || defined(CONFIG_MPC866)
40 #if defined(CONFIG_SOFT_I2C_GPIO_SCL)
41 # include <asm/gpio.h>
43 # ifndef I2C_GPIO_SYNC
44 # define I2C_GPIO_SYNC
50 gpio_request(CONFIG_SOFT_I2C_GPIO_SCL, "soft_i2c"); \
51 gpio_request(CONFIG_SOFT_I2C_GPIO_SDA, "soft_i2c"); \
56 # define I2C_ACTIVE do { } while (0)
60 # define I2C_TRISTATE do { } while (0)
64 # define I2C_READ gpio_get_value(CONFIG_SOFT_I2C_GPIO_SDA)
68 # define I2C_SDA(bit) \
71 gpio_direction_input(CONFIG_SOFT_I2C_GPIO_SDA); \
73 gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SDA, 0); \
79 # define I2C_SCL(bit) \
81 gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SCL, bit); \
87 # define I2C_DELAY udelay(5) /* 1/4 I2C clock duration */
92 /* #define DEBUG_I2C */
94 DECLARE_GLOBAL_DATA_PTR;
96 #ifndef I2C_SOFT_DECLARATIONS
97 # if defined(CONFIG_MPC8260)
98 # define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = \
99 ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
100 # elif defined(CONFIG_8xx)
101 # define I2C_SOFT_DECLARATIONS volatile immap_t *immr = \
102 (immap_t *)CONFIG_SYS_IMMR;
104 # define I2C_SOFT_DECLARATIONS
108 #if !defined(CONFIG_SYS_SOFT_I2C_SPEED)
109 #define CONFIG_SYS_SOFT_I2C_SPEED CONFIG_SYS_I2C_SPEED
111 #if !defined(CONFIG_SYS_SOFT_I2C_SLAVE)
112 #define CONFIG_SYS_SOFT_I2C_SLAVE CONFIG_SYS_I2C_SLAVE
115 /*-----------------------------------------------------------------------
120 #define I2C_ACK 0 /* PD_SDA level to ack a byte */
121 #define I2C_NOACK 1 /* PD_SDA level to noack a byte */
125 #define PRINTD(fmt,args...) do { \
126 printf (fmt ,##args); \
129 #define PRINTD(fmt,args...)
132 /*-----------------------------------------------------------------------
135 #if !defined(CONFIG_SYS_I2C_INIT_BOARD)
136 static void send_reset (void);
138 static void send_start (void);
139 static void send_stop (void);
140 static void send_ack (int);
141 static int write_byte (uchar byte);
142 static uchar read_byte (int);
144 #if !defined(CONFIG_SYS_I2C_INIT_BOARD)
145 /*-----------------------------------------------------------------------
146 * Send a reset sequence consisting of 9 clocks with the data signal high
147 * to clock any confused device back into an idle state. Also send a
148 * <stop> at the end of the sequence for belts & suspenders.
150 static void send_reset(void)
152 I2C_SOFT_DECLARATIONS /* intentional without ';' */
161 for(j = 0; j < 9; j++) {
174 /*-----------------------------------------------------------------------
175 * START: High -> Low on SDA while SCL is High
177 static void send_start(void)
179 I2C_SOFT_DECLARATIONS /* intentional without ';' */
191 /*-----------------------------------------------------------------------
192 * STOP: Low -> High on SDA while SCL is High
194 static void send_stop(void)
196 I2C_SOFT_DECLARATIONS /* intentional without ';' */
210 /*-----------------------------------------------------------------------
211 * ack should be I2C_ACK or I2C_NOACK
213 static void send_ack(int ack)
215 I2C_SOFT_DECLARATIONS /* intentional without ';' */
229 /*-----------------------------------------------------------------------
230 * Send 8 bits and look for an acknowledgement.
232 static int write_byte(uchar data)
234 I2C_SOFT_DECLARATIONS /* intentional without ';' */
239 for(j = 0; j < 8; j++) {
242 I2C_SDA(data & 0x80);
252 * Look for an <ACK>(negative logic) and return it.
267 return(nack); /* not a nack is an ack */
270 /*-----------------------------------------------------------------------
271 * if ack == I2C_ACK, ACK the byte so can continue reading, else
272 * send I2C_NOACK to end the read.
274 static uchar read_byte(int ack)
276 I2C_SOFT_DECLARATIONS /* intentional without ';' */
281 * Read 8 bits, MSB first.
286 for(j = 0; j < 8; j++) {
300 /*-----------------------------------------------------------------------
303 static void soft_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
305 #if defined(CONFIG_SYS_I2C_INIT_BOARD)
306 /* call board specific i2c bus reset routine before accessing the */
307 /* environment, which might be in a chip on that bus. For details */
308 /* about this problem see doc/I2C_Edge_Conditions. */
312 * WARNING: Do NOT save speed in a static variable: if the
313 * I2C routines are called before RAM is initialized (to read
314 * the DIMM SPD, for instance), RAM won't be usable and your
321 /*-----------------------------------------------------------------------
322 * Probe to see if a chip is present. Also good for checking for the
323 * completion of EEPROM writes since the chip stops responding until
324 * the write completes (typically 10mSec).
326 static int soft_i2c_probe(struct i2c_adapter *adap, uint8_t addr)
331 * perform 1 byte write transaction with just address byte
335 rc = write_byte ((addr << 1) | 0);
341 /*-----------------------------------------------------------------------
344 static int soft_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
345 int alen, uchar *buffer, int len)
348 PRINTD("i2c_read: chip %02X addr %02X alen %d buffer %p len %d\n",
349 chip, addr, alen, buffer, len);
351 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
353 * EEPROM chips that implement "address overflow" are ones
354 * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
355 * address and the extra bits end up in the "chip address"
356 * bit slots. This makes a 24WC08 (1Kbyte) chip look like
357 * four 256 byte chips.
359 * Note that we consider the length of the address field to
360 * still be one byte because the extra address bits are
361 * hidden in the chip address.
363 chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
365 PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n",
370 * Do the addressing portion of a write cycle to set the
371 * chip's address pointer. If the address length is zero,
372 * don't do the normal write cycle to set the address pointer,
373 * there is no address pointer in this chip.
377 if(write_byte(chip << 1)) { /* write cycle */
379 PRINTD("i2c_read, no chip responded %02X\n", chip);
382 shift = (alen-1) * 8;
384 if(write_byte(addr >> shift)) {
385 PRINTD("i2c_read, address not <ACK>ed\n");
391 /* Some I2C chips need a stop/start sequence here,
392 * other chips don't work with a full stop and need
393 * only a start. Default behaviour is to send the
394 * stop/start sequence.
396 #ifdef CONFIG_SOFT_I2C_READ_REPEATED_START
404 * Send the chip address again, this time for a read cycle.
405 * Then read the data. On the last byte, we do a NACK instead
406 * of an ACK(len == 0) to terminate the read.
408 write_byte((chip << 1) | 1); /* read cycle */
410 *buffer++ = read_byte(len == 0);
416 /*-----------------------------------------------------------------------
419 static int soft_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
420 int alen, uchar *buffer, int len)
422 int shift, failures = 0;
424 PRINTD("i2c_write: chip %02X addr %02X alen %d buffer %p len %d\n",
425 chip, addr, alen, buffer, len);
428 if(write_byte(chip << 1)) { /* write cycle */
430 PRINTD("i2c_write, no chip responded %02X\n", chip);
433 shift = (alen-1) * 8;
435 if(write_byte(addr >> shift)) {
436 PRINTD("i2c_write, address not <ACK>ed\n");
443 if(write_byte(*buffer++)) {
452 * Register soft i2c adapters
454 U_BOOT_I2C_ADAP_COMPLETE(soft0, soft_i2c_init, soft_i2c_probe,
455 soft_i2c_read, soft_i2c_write, NULL,
456 CONFIG_SYS_I2C_SOFT_SPEED, CONFIG_SYS_I2C_SOFT_SLAVE,
458 #if defined(I2C_SOFT_DECLARATIONS2)
459 U_BOOT_I2C_ADAP_COMPLETE(soft1, soft_i2c_init, soft_i2c_probe,
460 soft_i2c_read, soft_i2c_write, NULL,
461 CONFIG_SYS_I2C_SOFT_SPEED_2,
462 CONFIG_SYS_I2C_SOFT_SLAVE_2,
465 #if defined(I2C_SOFT_DECLARATIONS3)
466 U_BOOT_I2C_ADAP_COMPLETE(soft2, soft_i2c_init, soft_i2c_probe,
467 soft_i2c_read, soft_i2c_write, NULL,
468 CONFIG_SYS_I2C_SOFT_SPEED_3,
469 CONFIG_SYS_I2C_SOFT_SLAVE_3,
472 #if defined(I2C_SOFT_DECLARATIONS4)
473 U_BOOT_I2C_ADAP_COMPLETE(soft3, soft_i2c_init, soft_i2c_probe,
474 soft_i2c_read, soft_i2c_write, NULL,
475 CONFIG_SYS_I2C_SOFT_SPEED_4,
476 CONFIG_SYS_I2C_SOFT_SLAVE_4,