--- /dev/null
+/*
+ * (C) Copyright 2009
+ * Heiko Schocher, DENX Software Engineering, hs@denx.de.
+ * Changes for multibus/multiadapter I2C support.
+ *
+ * (C) Copyright 2001, 2002
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This has been changed substantially by Gerald Van Baren, Custom IDEAS,
+ * vanbaren@cideas.com. It was heavily influenced by LiMon, written by
+ * Neil Russell.
+ */
+
+#include <common.h>
+#ifdef CONFIG_MPC8260 /* only valid for MPC8260 */
+#include <ioports.h>
+#include <asm/io.h>
+#endif
+#if defined(CONFIG_AVR32)
+#include <asm/arch/portmux.h>
+#endif
+#if defined(CONFIG_AT91FAMILY)
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/at91_pio.h>
+#ifdef CONFIG_ATMEL_LEGACY
+#include <asm/arch/gpio.h>
+#endif
+#endif
+#if defined(CONFIG_MPC852T) || defined(CONFIG_MPC866)
+#include <asm/io.h>
+#endif
+#include <i2c.h>
+
+#if defined(CONFIG_SOFT_I2C_GPIO_SCL)
+# include <asm/gpio.h>
+
+# ifndef I2C_GPIO_SYNC
+# define I2C_GPIO_SYNC
+# endif
+
+# ifndef I2C_INIT
+# define I2C_INIT \
+ do { \
+ gpio_request(CONFIG_SOFT_I2C_GPIO_SCL, "soft_i2c"); \
+ gpio_request(CONFIG_SOFT_I2C_GPIO_SDA, "soft_i2c"); \
+ } while (0)
+# endif
+
+# ifndef I2C_ACTIVE
+# define I2C_ACTIVE do { } while (0)
+# endif
+
+# ifndef I2C_TRISTATE
+# define I2C_TRISTATE do { } while (0)
+# endif
+
+# ifndef I2C_READ
+# define I2C_READ gpio_get_value(CONFIG_SOFT_I2C_GPIO_SDA)
+# endif
+
+# ifndef I2C_SDA
+# define I2C_SDA(bit) \
+ do { \
+ if (bit) \
+ gpio_direction_input(CONFIG_SOFT_I2C_GPIO_SDA); \
+ else \
+ gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SDA, 0); \
+ I2C_GPIO_SYNC; \
+ } while (0)
+# endif
+
+# ifndef I2C_SCL
+# define I2C_SCL(bit) \
+ do { \
+ gpio_direction_output(CONFIG_SOFT_I2C_GPIO_SCL, bit); \
+ I2C_GPIO_SYNC; \
+ } while (0)
+# endif
+
+# ifndef I2C_DELAY
+# define I2C_DELAY udelay(5) /* 1/4 I2C clock duration */
+# endif
+
+#endif
+
+/* #define DEBUG_I2C */
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifndef I2C_SOFT_DECLARATIONS
+# if defined(CONFIG_MPC8260)
+# define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = \
+ ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
+# elif defined(CONFIG_8xx)
+# define I2C_SOFT_DECLARATIONS volatile immap_t *immr = \
+ (immap_t *)CONFIG_SYS_IMMR;
+# else
+# define I2C_SOFT_DECLARATIONS
+# endif
+#endif
+
+#if !defined(CONFIG_SYS_I2C_SOFT_SPEED)
+#define CONFIG_SYS_I2C_SOFT_SPEED CONFIG_SYS_I2C_SPEED
+#endif
+#if !defined(CONFIG_SYS_I2C_SOFT_SLAVE)
+#define CONFIG_SYS_I2C_SOFT_SLAVE CONFIG_SYS_I2C_SLAVE
+#endif
+
+/*-----------------------------------------------------------------------
+ * Definitions
+ */
+#define RETRIES 0
+
+#define I2C_ACK 0 /* PD_SDA level to ack a byte */
+#define I2C_NOACK 1 /* PD_SDA level to noack a byte */
+
+
+#ifdef DEBUG_I2C
+#define PRINTD(fmt,args...) do { \
+ printf (fmt ,##args); \
+ } while (0)
+#else
+#define PRINTD(fmt,args...)
+#endif
+
+/*-----------------------------------------------------------------------
+ * Local functions
+ */
+#if !defined(CONFIG_SYS_I2C_INIT_BOARD)
+static void send_reset (void);
+#endif
+static void send_start (void);
+static void send_stop (void);
+static void send_ack (int);
+static int write_byte (uchar byte);
+static uchar read_byte (int);
+
+#if !defined(CONFIG_SYS_I2C_INIT_BOARD)
+/*-----------------------------------------------------------------------
+ * Send a reset sequence consisting of 9 clocks with the data signal high
+ * to clock any confused device back into an idle state. Also send a
+ * <stop> at the end of the sequence for belts & suspenders.
+ */
+static void send_reset(void)
+{
+ I2C_SOFT_DECLARATIONS /* intentional without ';' */
+ int j;
+
+ I2C_SCL(1);
+ I2C_SDA(1);
+#ifdef I2C_INIT
+ I2C_INIT;
+#endif
+ I2C_TRISTATE;
+ for(j = 0; j < 9; j++) {
+ I2C_SCL(0);
+ I2C_DELAY;
+ I2C_DELAY;
+ I2C_SCL(1);
+ I2C_DELAY;
+ I2C_DELAY;
+ }
+ send_stop();
+ I2C_TRISTATE;
+}
+#endif
+
+/*-----------------------------------------------------------------------
+ * START: High -> Low on SDA while SCL is High
+ */
+static void send_start(void)
+{
+ I2C_SOFT_DECLARATIONS /* intentional without ';' */
+
+ I2C_DELAY;
+ I2C_SDA(1);
+ I2C_ACTIVE;
+ I2C_DELAY;
+ I2C_SCL(1);
+ I2C_DELAY;
+ I2C_SDA(0);
+ I2C_DELAY;
+}
+
+/*-----------------------------------------------------------------------
+ * STOP: Low -> High on SDA while SCL is High
+ */
+static void send_stop(void)
+{
+ I2C_SOFT_DECLARATIONS /* intentional without ';' */
+
+ I2C_SCL(0);
+ I2C_DELAY;
+ I2C_SDA(0);
+ I2C_ACTIVE;
+ I2C_DELAY;
+ I2C_SCL(1);
+ I2C_DELAY;
+ I2C_SDA(1);
+ I2C_DELAY;
+ I2C_TRISTATE;
+}
+
+/*-----------------------------------------------------------------------
+ * ack should be I2C_ACK or I2C_NOACK
+ */
+static void send_ack(int ack)
+{
+ I2C_SOFT_DECLARATIONS /* intentional without ';' */
+
+ I2C_SCL(0);
+ I2C_DELAY;
+ I2C_ACTIVE;
+ I2C_SDA(ack);
+ I2C_DELAY;
+ I2C_SCL(1);
+ I2C_DELAY;
+ I2C_DELAY;
+ I2C_SCL(0);
+ I2C_DELAY;
+}
+
+/*-----------------------------------------------------------------------
+ * Send 8 bits and look for an acknowledgement.
+ */
+static int write_byte(uchar data)
+{
+ I2C_SOFT_DECLARATIONS /* intentional without ';' */
+ int j;
+ int nack;
+
+ I2C_ACTIVE;
+ for(j = 0; j < 8; j++) {
+ I2C_SCL(0);
+ I2C_DELAY;
+ I2C_SDA(data & 0x80);
+ I2C_DELAY;
+ I2C_SCL(1);
+ I2C_DELAY;
+ I2C_DELAY;
+
+ data <<= 1;
+ }
+
+ /*
+ * Look for an <ACK>(negative logic) and return it.
+ */
+ I2C_SCL(0);
+ I2C_DELAY;
+ I2C_SDA(1);
+ I2C_TRISTATE;
+ I2C_DELAY;
+ I2C_SCL(1);
+ I2C_DELAY;
+ I2C_DELAY;
+ nack = I2C_READ;
+ I2C_SCL(0);
+ I2C_DELAY;
+ I2C_ACTIVE;
+
+ return(nack); /* not a nack is an ack */
+}
+
+/*-----------------------------------------------------------------------
+ * if ack == I2C_ACK, ACK the byte so can continue reading, else
+ * send I2C_NOACK to end the read.
+ */
+static uchar read_byte(int ack)
+{
+ I2C_SOFT_DECLARATIONS /* intentional without ';' */
+ int data;
+ int j;
+
+ /*
+ * Read 8 bits, MSB first.
+ */
+ I2C_TRISTATE;
+ I2C_SDA(1);
+ data = 0;
+ for(j = 0; j < 8; j++) {
+ I2C_SCL(0);
+ I2C_DELAY;
+ I2C_SCL(1);
+ I2C_DELAY;
+ data <<= 1;
+ data |= I2C_READ;
+ I2C_DELAY;
+ }
+ send_ack(ack);
+
+ return(data);
+}
+
+/*-----------------------------------------------------------------------
+ * Initialization
+ */
+static void soft_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
+{
+#if defined(CONFIG_SYS_I2C_INIT_BOARD)
+ /* call board specific i2c bus reset routine before accessing the */
+ /* environment, which might be in a chip on that bus. For details */
+ /* about this problem see doc/I2C_Edge_Conditions. */
+ i2c_init_board();
+#else
+ /*
+ * WARNING: Do NOT save speed in a static variable: if the
+ * I2C routines are called before RAM is initialized (to read
+ * the DIMM SPD, for instance), RAM won't be usable and your
+ * system will crash.
+ */
+ send_reset ();
+#endif
+}
+
+/*-----------------------------------------------------------------------
+ * Probe to see if a chip is present. Also good for checking for the
+ * completion of EEPROM writes since the chip stops responding until
+ * the write completes (typically 10mSec).
+ */
+static int soft_i2c_probe(struct i2c_adapter *adap, uint8_t addr)
+{
+ int rc;
+
+ /*
+ * perform 1 byte write transaction with just address byte
+ * (fake write)
+ */
+ send_start();
+ rc = write_byte ((addr << 1) | 0);
+ send_stop();
+
+ return (rc ? 1 : 0);
+}
+
+/*-----------------------------------------------------------------------
+ * Read bytes
+ */
+static int soft_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
+ int alen, uchar *buffer, int len)
+{
+ int shift;
+ PRINTD("i2c_read: chip %02X addr %02X alen %d buffer %p len %d\n",
+ chip, addr, alen, buffer, len);
+
+#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
+ /*
+ * EEPROM chips that implement "address overflow" are ones
+ * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
+ * address and the extra bits end up in the "chip address"
+ * bit slots. This makes a 24WC08 (1Kbyte) chip look like
+ * four 256 byte chips.
+ *
+ * Note that we consider the length of the address field to
+ * still be one byte because the extra address bits are
+ * hidden in the chip address.
+ */
+ chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
+
+ PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n",
+ chip, addr);
+#endif
+
+ /*
+ * Do the addressing portion of a write cycle to set the
+ * chip's address pointer. If the address length is zero,
+ * don't do the normal write cycle to set the address pointer,
+ * there is no address pointer in this chip.
+ */
+ send_start();
+ if(alen > 0) {
+ if(write_byte(chip << 1)) { /* write cycle */
+ send_stop();
+ PRINTD("i2c_read, no chip responded %02X\n", chip);
+ return(1);
+ }
+ shift = (alen-1) * 8;
+ while(alen-- > 0) {
+ if(write_byte(addr >> shift)) {
+ PRINTD("i2c_read, address not <ACK>ed\n");
+ return(1);
+ }
+ shift -= 8;
+ }
+
+ /* Some I2C chips need a stop/start sequence here,
+ * other chips don't work with a full stop and need
+ * only a start. Default behaviour is to send the
+ * stop/start sequence.
+ */
+#ifdef CONFIG_SOFT_I2C_READ_REPEATED_START
+ send_start();
+#else
+ send_stop();
+ send_start();
+#endif
+ }
+ /*
+ * Send the chip address again, this time for a read cycle.
+ * Then read the data. On the last byte, we do a NACK instead
+ * of an ACK(len == 0) to terminate the read.
+ */
+ write_byte((chip << 1) | 1); /* read cycle */
+ while(len-- > 0) {
+ *buffer++ = read_byte(len == 0);
+ }
+ send_stop();
+ return(0);
+}
+
+/*-----------------------------------------------------------------------
+ * Write bytes
+ */
+static int soft_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
+ int alen, uchar *buffer, int len)
+{
+ int shift, failures = 0;
+
+ PRINTD("i2c_write: chip %02X addr %02X alen %d buffer %p len %d\n",
+ chip, addr, alen, buffer, len);
+
+ send_start();
+ if(write_byte(chip << 1)) { /* write cycle */
+ send_stop();
+ PRINTD("i2c_write, no chip responded %02X\n", chip);
+ return(1);
+ }
+ shift = (alen-1) * 8;
+ while(alen-- > 0) {
+ if(write_byte(addr >> shift)) {
+ PRINTD("i2c_write, address not <ACK>ed\n");
+ return(1);
+ }
+ shift -= 8;
+ }
+
+ while(len-- > 0) {
+ if(write_byte(*buffer++)) {
+ failures++;
+ }
+ }
+ send_stop();
+ return(failures);
+}
+
+/*
+ * Register soft i2c adapters
+ */
+U_BOOT_I2C_ADAP_COMPLETE(soft0, soft_i2c_init, soft_i2c_probe,
+ soft_i2c_read, soft_i2c_write, NULL,
+ CONFIG_SYS_I2C_SOFT_SPEED, CONFIG_SYS_I2C_SOFT_SLAVE,
+ 0)
+#if defined(I2C_SOFT_DECLARATIONS2)
+U_BOOT_I2C_ADAP_COMPLETE(soft1, soft_i2c_init, soft_i2c_probe,
+ soft_i2c_read, soft_i2c_write, NULL,
+ CONFIG_SYS_I2C_SOFT_SPEED_2,
+ CONFIG_SYS_I2C_SOFT_SLAVE_2,
+ 1)
+#endif
+#if defined(I2C_SOFT_DECLARATIONS3)
+U_BOOT_I2C_ADAP_COMPLETE(soft2, soft_i2c_init, soft_i2c_probe,
+ soft_i2c_read, soft_i2c_write, NULL,
+ CONFIG_SYS_I2C_SOFT_SPEED_3,
+ CONFIG_SYS_I2C_SOFT_SLAVE_3,
+ 2)
+#endif
+#if defined(I2C_SOFT_DECLARATIONS4)
+U_BOOT_I2C_ADAP_COMPLETE(soft3, soft_i2c_init, soft_i2c_probe,
+ soft_i2c_read, soft_i2c_write, NULL,
+ CONFIG_SYS_I2C_SOFT_SPEED_4,
+ CONFIG_SYS_I2C_SOFT_SLAVE_4,
+ 3)
+#endif
Code Review / kvmfornfv.git / blobdiff