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_ATMEL_LEGACY
29 #include <asm/arch/gpio.h>
32 #if defined(CONFIG_MPC852T) || defined(CONFIG_MPC866)
37 #if defined(CONFIG_SOFT_I2C_GPIO_SCL)
38 # include <asm/gpio.h>
40 # ifndef I2C_GPIO_SYNC
41 # define I2C_GPIO_SYNC
47 gpio_request(CONFIG_SOFT_I2C_GPIO_SCL, "soft_i2c"); \
48 gpio_request(CONFIG_SOFT_I2C_GPIO_SDA, "soft_i2c"); \
53 # define I2C_ACTIVE do { } while (0)
57 # define I2C_TRISTATE do { } while (0)
61 # define I2C_READ gpio_get_value(CONFIG_SOFT_I2C_GPIO_SDA)
65 # define I2C_SDA(bit) \
68 gpio_direction_input(CONFIG_SOFT_I2C_GPIO_SDA); \
70 gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SDA, 0); \
76 # define I2C_SCL(bit) \
78 gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SCL, bit); \
84 # define I2C_DELAY udelay(5) /* 1/4 I2C clock duration */
89 /* #define DEBUG_I2C */
91 DECLARE_GLOBAL_DATA_PTR;
93 #ifndef I2C_SOFT_DECLARATIONS
94 # if defined(CONFIG_MPC8260)
95 # define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = \
96 ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
97 # elif defined(CONFIG_8xx)
98 # define I2C_SOFT_DECLARATIONS volatile immap_t *immr = \
99 (immap_t *)CONFIG_SYS_IMMR;
101 # define I2C_SOFT_DECLARATIONS
105 #if !defined(CONFIG_SYS_I2C_SOFT_SPEED)
106 #define CONFIG_SYS_I2C_SOFT_SPEED CONFIG_SYS_I2C_SPEED
108 #if !defined(CONFIG_SYS_I2C_SOFT_SLAVE)
109 #define CONFIG_SYS_I2C_SOFT_SLAVE CONFIG_SYS_I2C_SLAVE
112 /*-----------------------------------------------------------------------
117 #define I2C_ACK 0 /* PD_SDA level to ack a byte */
118 #define I2C_NOACK 1 /* PD_SDA level to noack a byte */
122 #define PRINTD(fmt,args...) do { \
123 printf (fmt ,##args); \
126 #define PRINTD(fmt,args...)
129 /*-----------------------------------------------------------------------
132 #if !defined(CONFIG_SYS_I2C_INIT_BOARD)
133 static void send_reset (void);
135 static void send_start (void);
136 static void send_stop (void);
137 static void send_ack (int);
138 static int write_byte (uchar byte);
139 static uchar read_byte (int);
141 #if !defined(CONFIG_SYS_I2C_INIT_BOARD)
142 /*-----------------------------------------------------------------------
143 * Send a reset sequence consisting of 9 clocks with the data signal high
144 * to clock any confused device back into an idle state. Also send a
145 * <stop> at the end of the sequence for belts & suspenders.
147 static void send_reset(void)
149 I2C_SOFT_DECLARATIONS /* intentional without ';' */
158 for(j = 0; j < 9; j++) {
171 /*-----------------------------------------------------------------------
172 * START: High -> Low on SDA while SCL is High
174 static void send_start(void)
176 I2C_SOFT_DECLARATIONS /* intentional without ';' */
188 /*-----------------------------------------------------------------------
189 * STOP: Low -> High on SDA while SCL is High
191 static void send_stop(void)
193 I2C_SOFT_DECLARATIONS /* intentional without ';' */
207 /*-----------------------------------------------------------------------
208 * ack should be I2C_ACK or I2C_NOACK
210 static void send_ack(int ack)
212 I2C_SOFT_DECLARATIONS /* intentional without ';' */
226 /*-----------------------------------------------------------------------
227 * Send 8 bits and look for an acknowledgement.
229 static int write_byte(uchar data)
231 I2C_SOFT_DECLARATIONS /* intentional without ';' */
236 for(j = 0; j < 8; j++) {
239 I2C_SDA(data & 0x80);
249 * Look for an <ACK>(negative logic) and return it.
264 return(nack); /* not a nack is an ack */
267 /*-----------------------------------------------------------------------
268 * if ack == I2C_ACK, ACK the byte so can continue reading, else
269 * send I2C_NOACK to end the read.
271 static uchar read_byte(int ack)
273 I2C_SOFT_DECLARATIONS /* intentional without ';' */
278 * Read 8 bits, MSB first.
283 for(j = 0; j < 8; j++) {
297 /*-----------------------------------------------------------------------
300 static void soft_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
302 #if defined(CONFIG_SYS_I2C_INIT_BOARD)
303 /* call board specific i2c bus reset routine before accessing the */
304 /* environment, which might be in a chip on that bus. For details */
305 /* about this problem see doc/I2C_Edge_Conditions. */
309 * WARNING: Do NOT save speed in a static variable: if the
310 * I2C routines are called before RAM is initialized (to read
311 * the DIMM SPD, for instance), RAM won't be usable and your
318 /*-----------------------------------------------------------------------
319 * Probe to see if a chip is present. Also good for checking for the
320 * completion of EEPROM writes since the chip stops responding until
321 * the write completes (typically 10mSec).
323 static int soft_i2c_probe(struct i2c_adapter *adap, uint8_t addr)
328 * perform 1 byte write transaction with just address byte
332 rc = write_byte ((addr << 1) | 0);
338 /*-----------------------------------------------------------------------
341 static int soft_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
342 int alen, uchar *buffer, int len)
345 PRINTD("i2c_read: chip %02X addr %02X alen %d buffer %p len %d\n",
346 chip, addr, alen, buffer, len);
348 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
350 * EEPROM chips that implement "address overflow" are ones
351 * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
352 * address and the extra bits end up in the "chip address"
353 * bit slots. This makes a 24WC08 (1Kbyte) chip look like
354 * four 256 byte chips.
356 * Note that we consider the length of the address field to
357 * still be one byte because the extra address bits are
358 * hidden in the chip address.
360 chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
362 PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n",
367 * Do the addressing portion of a write cycle to set the
368 * chip's address pointer. If the address length is zero,
369 * don't do the normal write cycle to set the address pointer,
370 * there is no address pointer in this chip.
374 if(write_byte(chip << 1)) { /* write cycle */
376 PRINTD("i2c_read, no chip responded %02X\n", chip);
379 shift = (alen-1) * 8;
381 if(write_byte(addr >> shift)) {
382 PRINTD("i2c_read, address not <ACK>ed\n");
388 /* Some I2C chips need a stop/start sequence here,
389 * other chips don't work with a full stop and need
390 * only a start. Default behaviour is to send the
391 * stop/start sequence.
393 #ifdef CONFIG_SOFT_I2C_READ_REPEATED_START
401 * Send the chip address again, this time for a read cycle.
402 * Then read the data. On the last byte, we do a NACK instead
403 * of an ACK(len == 0) to terminate the read.
405 write_byte((chip << 1) | 1); /* read cycle */
407 *buffer++ = read_byte(len == 0);
413 /*-----------------------------------------------------------------------
416 static int soft_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
417 int alen, uchar *buffer, int len)
419 int shift, failures = 0;
421 PRINTD("i2c_write: chip %02X addr %02X alen %d buffer %p len %d\n",
422 chip, addr, alen, buffer, len);
425 if(write_byte(chip << 1)) { /* write cycle */
427 PRINTD("i2c_write, no chip responded %02X\n", chip);
430 shift = (alen-1) * 8;
432 if(write_byte(addr >> shift)) {
433 PRINTD("i2c_write, address not <ACK>ed\n");
440 if(write_byte(*buffer++)) {
449 * Register soft i2c adapters
451 U_BOOT_I2C_ADAP_COMPLETE(soft0, soft_i2c_init, soft_i2c_probe,
452 soft_i2c_read, soft_i2c_write, NULL,
453 CONFIG_SYS_I2C_SOFT_SPEED, CONFIG_SYS_I2C_SOFT_SLAVE,
455 #if defined(I2C_SOFT_DECLARATIONS2)
456 U_BOOT_I2C_ADAP_COMPLETE(soft1, soft_i2c_init, soft_i2c_probe,
457 soft_i2c_read, soft_i2c_write, NULL,
458 CONFIG_SYS_I2C_SOFT_SPEED_2,
459 CONFIG_SYS_I2C_SOFT_SLAVE_2,
462 #if defined(I2C_SOFT_DECLARATIONS3)
463 U_BOOT_I2C_ADAP_COMPLETE(soft2, soft_i2c_init, soft_i2c_probe,
464 soft_i2c_read, soft_i2c_write, NULL,
465 CONFIG_SYS_I2C_SOFT_SPEED_3,
466 CONFIG_SYS_I2C_SOFT_SLAVE_3,
469 #if defined(I2C_SOFT_DECLARATIONS4)
470 U_BOOT_I2C_ADAP_COMPLETE(soft3, soft_i2c_init, soft_i2c_probe,
471 soft_i2c_read, soft_i2c_write, NULL,
472 CONFIG_SYS_I2C_SOFT_SPEED_4,
473 CONFIG_SYS_I2C_SOFT_SLAVE_4,