Initial revision
diff --git a/cpu/mpc8260/i2c.c b/cpu/mpc8260/i2c.c
new file mode 100644
index 0000000..8bfa2e8
--- /dev/null
+++ b/cpu/mpc8260/i2c.c
@@ -0,0 +1,733 @@
+/*
+ * (C) Copyright 2000
+ * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
+ *
+ * (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+
+#if defined(CONFIG_HARD_I2C)
+
+#include <asm/cpm_8260.h>
+#include <i2c.h>
+
+/* define to enable debug messages */
+#undef DEBUG_I2C
+
+/* uSec to wait between polls of the i2c */
+#define DELAY_US 100
+/* uSec to wait for the CPM to start processing the buffer */
+#define START_DELAY_US 1000
+
+/*
+ * tx/rx per-byte timeout: we delay DELAY_US uSec between polls so the
+ * timeout will be (tx_length + rx_length) * DELAY_US * TOUT_LOOP
+ */
+#define TOUT_LOOP 5
+
+/*-----------------------------------------------------------------------
+ * Set default values
+ */
+#ifndef CFG_I2C_SPEED
+#define CFG_I2C_SPEED 50000
+#endif
+
+#ifndef CFG_I2C_SLAVE
+#define CFG_I2C_SLAVE 0xFE
+#endif
+/*-----------------------------------------------------------------------
+ */
+
+typedef void (*i2c_ecb_t)(int, int); /* error callback function */
+
+/* This structure keeps track of the bd and buffer space usage. */
+typedef struct i2c_state {
+ int rx_idx; /* index to next free Rx BD */
+ int tx_idx; /* index to next free Tx BD */
+ void *rxbd; /* pointer to next free Rx BD */
+ void *txbd; /* pointer to next free Tx BD */
+ int tx_space; /* number of Tx bytes left */
+ unsigned char *tx_buf; /* pointer to free Tx area */
+ i2c_ecb_t err_cb; /* error callback function */
+} i2c_state_t;
+
+/* flags for i2c_send() and i2c_receive() */
+#define I2CF_ENABLE_SECONDARY 0x01 /* secondary_address is valid */
+#define I2CF_START_COND 0x02 /* tx: generate start condition */
+#define I2CF_STOP_COND 0x04 /* tx: generate stop condition */
+
+/* return codes */
+#define I2CERR_NO_BUFFERS 0x01 /* no more BDs or buffer space */
+#define I2CERR_MSG_TOO_LONG 0x02 /* tried to send/receive to much data */
+#define I2CERR_TIMEOUT 0x03 /* timeout in i2c_doio() */
+#define I2CERR_QUEUE_EMPTY 0x04 /* i2c_doio called without send/receive */
+
+/* error callback flags */
+#define I2CECB_RX_ERR 0x10 /* this is a receive error */
+#define I2CECB_RX_ERR_OV 0x02 /* receive overrun error */
+#define I2CECB_RX_MASK 0x0f /* mask for error bits */
+#define I2CECB_TX_ERR 0x20 /* this is a transmit error */
+#define I2CECB_TX_CL 0x01 /* transmit collision error */
+#define I2CECB_TX_UN 0x02 /* transmit underflow error */
+#define I2CECB_TX_NAK 0x04 /* transmit no ack error */
+#define I2CECB_TX_MASK 0x0f /* mask for error bits */
+#define I2CECB_TIMEOUT 0x40 /* this is a timeout error */
+
+#define ERROR_I2C_NONE 0
+#define ERROR_I2C_LENGTH 1
+
+#define I2C_WRITE_BIT 0x00
+#define I2C_READ_BIT 0x01
+
+#define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
+
+
+#define NUM_RX_BDS 4
+#define NUM_TX_BDS 4
+#define MAX_TX_SPACE 256
+
+typedef struct I2C_BD
+{
+ unsigned short status;
+ unsigned short length;
+ unsigned char *addr;
+} I2C_BD;
+#define BD_I2C_TX_START 0x0400 /* special status for i2c: Start condition */
+
+#define BD_I2C_TX_CL 0x0001 /* collision error */
+#define BD_I2C_TX_UN 0x0002 /* underflow error */
+#define BD_I2C_TX_NAK 0x0004 /* no acknowledge error */
+#define BD_I2C_TX_ERR (BD_I2C_TX_NAK|BD_I2C_TX_UN|BD_I2C_TX_CL)
+
+#define BD_I2C_RX_ERR BD_SC_OV
+
+#ifdef DEBUG_I2C
+#define PRINTD(x) printf x
+#else
+#define PRINTD(x)
+#endif
+
+/*
+ * Returns the best value of I2BRG to meet desired clock speed of I2C with
+ * input parameters (clock speed, filter, and predivider value).
+ * It returns computer speed value and the difference between it and desired
+ * speed.
+ */
+static inline int
+i2c_roundrate(int hz, int speed, int filter, int modval,
+ int *brgval, int *totspeed)
+{
+ int moddiv = 1 << (5-(modval & 3)), brgdiv, div;
+
+ PRINTD(("\t[I2C] trying hz=%d, speed=%d, filter=%d, modval=%d\n",
+ hz, speed, filter, modval));
+
+ div = moddiv * speed;
+ brgdiv = (hz + div - 1) / div;
+
+ PRINTD(("\t\tmoddiv=%d, brgdiv=%d\n", moddiv, brgdiv));
+
+ *brgval = (brgdiv / 2) - 3 - (2*filter);
+
+ if ((*brgval < 0) || (*brgval > 255)) {
+ PRINTD(("\t\trejected brgval=%d\n", *brgval));
+ return -1;
+ }
+
+ brgdiv = 2 * (*brgval + 3 + (2 * filter));
+ div = moddiv * brgdiv ;
+ *totspeed = (hz + div - 1) / div;
+
+ PRINTD(("\t\taccepted brgval=%d, totspeed=%d\n", *brgval, *totspeed));
+
+ return 0;
+}
+
+/*
+ * Sets the I2C clock predivider and divider to meet required clock speed.
+ */
+static int i2c_setrate(int hz, int speed)
+{
+ immap_t *immap = (immap_t *)CFG_IMMR ;
+ volatile i2c8260_t *i2c = (i2c8260_t *)&immap->im_i2c;
+ int brgval,
+ modval, /* 0-3 */
+ bestspeed_diff = speed,
+ bestspeed_brgval=0,
+ bestspeed_modval=0,
+ bestspeed_filter=0,
+ totspeed,
+ filter = 0; /* Use this fixed value */
+
+ for (modval = 0; modval < 4; modval++)
+ {
+ if (i2c_roundrate (hz, speed, filter, modval, &brgval, &totspeed) == 0)
+ {
+ int diff = speed - totspeed ;
+
+ if ((diff >= 0) && (diff < bestspeed_diff))
+ {
+ bestspeed_diff = diff ;
+ bestspeed_modval = modval;
+ bestspeed_brgval = brgval;
+ bestspeed_filter = filter;
+ }
+ }
+ }
+
+ PRINTD(("[I2C] Best is:\n"));
+ PRINTD(("[I2C] CPU=%dhz RATE=%d F=%d I2MOD=%08x I2BRG=%08x DIFF=%dhz\n",
+ hz, speed,
+ bestspeed_filter, bestspeed_modval, bestspeed_brgval,
+ bestspeed_diff));
+
+ i2c->i2c_i2mod |= ((bestspeed_modval & 3) << 1) | (bestspeed_filter << 3);
+ i2c->i2c_i2brg = bestspeed_brgval & 0xff;
+
+ PRINTD(("[I2C] i2mod=%08x i2brg=%08x\n", i2c->i2c_i2mod, i2c->i2c_i2brg));
+
+ return 1 ;
+}
+
+void i2c_init(int speed, int slaveadd)
+{
+ DECLARE_GLOBAL_DATA_PTR;
+
+ volatile immap_t *immap = (immap_t *)CFG_IMMR ;
+ volatile cpm8260_t *cp = (cpm8260_t *)&immap->im_cpm;
+ volatile i2c8260_t *i2c = (i2c8260_t *)&immap->im_i2c;
+ volatile iic_t *iip;
+ ulong rbase, tbase;
+ volatile I2C_BD *rxbd, *txbd;
+ uint dpaddr;
+
+ dpaddr = *((unsigned short*)(&immap->im_dprambase[PROFF_I2C_BASE]));
+ if (dpaddr == 0) {
+ /* need to allocate dual port ram */
+ dpaddr = m8260_cpm_dpalloc(64 +
+ (NUM_RX_BDS * sizeof(I2C_BD)) + (NUM_TX_BDS * sizeof(I2C_BD)) +
+ MAX_TX_SPACE, 64);
+ *((unsigned short*)(&immap->im_dprambase[PROFF_I2C_BASE])) = dpaddr;
+ }
+
+ /*
+ * initialise data in dual port ram:
+ *
+ * dpaddr -> parameter ram (64 bytes)
+ * rbase -> rx BD (NUM_RX_BDS * sizeof(I2C_BD) bytes)
+ * tbase -> tx BD (NUM_TX_BDS * sizeof(I2C_BD) bytes)
+ * tx buffer (MAX_TX_SPACE bytes)
+ */
+
+ iip = (iic_t *)&immap->im_dprambase[dpaddr];
+ memset((void*)iip, 0, sizeof(iic_t));
+
+ rbase = dpaddr + 64;
+ tbase = rbase + NUM_RX_BDS * sizeof(I2C_BD);
+
+ /* Disable interrupts */
+ i2c->i2c_i2mod = 0x00;
+ i2c->i2c_i2cmr = 0x00;
+ i2c->i2c_i2cer = 0xff;
+ i2c->i2c_i2add = slaveadd;
+
+ /*
+ * Set the I2C BRG Clock division factor from desired i2c rate
+ * and current CPU rate (we assume sccr dfbgr field is 0;
+ * divide BRGCLK by 1)
+ */
+ PRINTD(("[I2C] Setting rate...\n"));
+ i2c_setrate (gd->brg_clk, CFG_I2C_SPEED) ;
+
+ /* Set I2C controller in master mode */
+ i2c->i2c_i2com = 0x01;
+
+ /* Initialize Tx/Rx parameters */
+ iip->iic_rbase = rbase;
+ iip->iic_tbase = tbase;
+ rxbd = (I2C_BD *)((unsigned char *)&immap->im_dprambase[iip->iic_rbase]);
+ txbd = (I2C_BD *)((unsigned char *)&immap->im_dprambase[iip->iic_tbase]);
+
+ PRINTD(("[I2C] rbase = %04x\n", iip->iic_rbase));
+ PRINTD(("[I2C] tbase = %04x\n", iip->iic_tbase));
+ PRINTD(("[I2C] rxbd = %08x\n", (int)rxbd));
+ PRINTD(("[I2C] txbd = %08x\n", (int)txbd));
+
+ /* Set big endian byte order */
+ iip->iic_tfcr = 0x10;
+ iip->iic_rfcr = 0x10;
+
+ /* Set maximum receive size. */
+ iip->iic_mrblr = I2C_RXTX_LEN;
+
+ cp->cp_cpcr = mk_cr_cmd(CPM_CR_I2C_PAGE,
+ CPM_CR_I2C_SBLOCK,
+ 0x00,
+ CPM_CR_INIT_TRX) | CPM_CR_FLG;
+ do {
+ __asm__ __volatile__ ("eieio");
+ } while (cp->cp_cpcr & CPM_CR_FLG);
+
+ /* Clear events and interrupts */
+ i2c->i2c_i2cer = 0xff;
+ i2c->i2c_i2cmr = 0x00;
+}
+
+static
+void i2c_newio(i2c_state_t *state)
+{
+ volatile immap_t *immap = (immap_t *)CFG_IMMR ;
+ volatile iic_t *iip;
+ uint dpaddr;
+
+ PRINTD(("[I2C] i2c_newio\n"));
+
+ dpaddr = *((unsigned short*)(&immap->im_dprambase[PROFF_I2C_BASE]));
+ iip = (iic_t *)&immap->im_dprambase[dpaddr];
+ state->rx_idx = 0;
+ state->tx_idx = 0;
+ state->rxbd = (void*)&immap->im_dprambase[iip->iic_rbase];
+ state->txbd = (void*)&immap->im_dprambase[iip->iic_tbase];
+ state->tx_space = MAX_TX_SPACE;
+ state->tx_buf = (uchar*)state->txbd + NUM_TX_BDS * sizeof(I2C_BD);
+ state->err_cb = NULL;
+
+ PRINTD(("[I2C] rxbd = %08x\n", (int)state->rxbd));
+ PRINTD(("[I2C] txbd = %08x\n", (int)state->txbd));
+ PRINTD(("[I2C] tx_buf = %08x\n", (int)state->tx_buf));
+
+ /* clear the buffer memory */
+ memset((char *)state->tx_buf, 0, MAX_TX_SPACE);
+}
+
+static
+int i2c_send(i2c_state_t *state,
+ unsigned char address,
+ unsigned char secondary_address,
+ unsigned int flags,
+ unsigned short size,
+ unsigned char *dataout)
+{
+ volatile I2C_BD *txbd;
+ int i,j;
+
+ PRINTD(("[I2C] i2c_send add=%02d sec=%02d flag=%02d size=%d\n",
+ address, secondary_address, flags, size));
+
+ /* trying to send message larger than BD */
+ if (size > I2C_RXTX_LEN)
+ return I2CERR_MSG_TOO_LONG;
+
+ /* no more free bds */
+ if (state->tx_idx >= NUM_TX_BDS || state->tx_space < (2 + size))
+ return I2CERR_NO_BUFFERS;
+
+ txbd = (I2C_BD *)state->txbd;
+ txbd->addr = state->tx_buf;
+
+ PRINTD(("[I2C] txbd = %08x\n", (int)txbd));
+
+ if (flags & I2CF_START_COND)
+ {
+ PRINTD(("[I2C] Formatting addresses...\n"));
+ if (flags & I2CF_ENABLE_SECONDARY)
+ {
+ txbd->length = size + 2; /* Length of message plus dest addresses */
+ txbd->addr[0] = address << 1;
+ txbd->addr[1] = secondary_address;
+ i = 2;
+ }
+ else
+ {
+ txbd->length = size + 1; /* Length of message plus dest address */
+ txbd->addr[0] = address << 1; /* Write destination address to BD */
+ i = 1;
+ }
+ }
+ else
+ {
+ txbd->length = size; /* Length of message */
+ i = 0;
+ }
+
+ /* set up txbd */
+ txbd->status = BD_SC_READY;
+ if (flags & I2CF_START_COND)
+ txbd->status |= BD_I2C_TX_START;
+ if (flags & I2CF_STOP_COND)
+ txbd->status |= BD_SC_LAST | BD_SC_WRAP;
+
+ /* Copy data to send into buffer */
+ PRINTD(("[I2C] copy data...\n"));
+ for(j = 0; j < size; i++, j++)
+ txbd->addr[i] = dataout[j];
+
+ PRINTD(("[I2C] txbd: length=0x%04x status=0x%04x addr[0]=0x%02x addr[1]=0x%02x\n",
+ txbd->length,
+ txbd->status,
+ txbd->addr[0],
+ txbd->addr[1]));
+
+ /* advance state */
+ state->tx_buf += txbd->length;
+ state->tx_space -= txbd->length;
+ state->tx_idx++;
+ state->txbd = (void*)(txbd + 1);
+
+ return 0;
+}
+
+static
+int i2c_receive(i2c_state_t *state,
+ unsigned char address,
+ unsigned char secondary_address,
+ unsigned int flags,
+ unsigned short size_to_expect,
+ unsigned char *datain)
+{
+ volatile I2C_BD *rxbd, *txbd;
+
+ PRINTD(("[I2C] i2c_receive %02d %02d %02d\n", address, secondary_address, flags));
+
+ /* Expected to receive too much */
+ if (size_to_expect > I2C_RXTX_LEN)
+ return I2CERR_MSG_TOO_LONG;
+
+ /* no more free bds */
+ if (state->tx_idx >= NUM_TX_BDS || state->rx_idx >= NUM_RX_BDS
+ || state->tx_space < 2)
+ return I2CERR_NO_BUFFERS;
+
+ rxbd = (I2C_BD *)state->rxbd;
+ txbd = (I2C_BD *)state->txbd;
+
+ PRINTD(("[I2C] rxbd = %08x\n", (int)rxbd));
+ PRINTD(("[I2C] txbd = %08x\n", (int)txbd));
+
+ txbd->addr = state->tx_buf;
+
+ /* set up TXBD for destination address */
+ if (flags & I2CF_ENABLE_SECONDARY)
+ {
+ txbd->length = 2;
+ txbd->addr[0] = address << 1; /* Write data */
+ txbd->addr[1] = secondary_address; /* Internal address */
+ txbd->status = BD_SC_READY;
+ }
+ else
+ {
+ txbd->length = 1 + size_to_expect;
+ txbd->addr[0] = (address << 1) | 0x01;
+ txbd->status = BD_SC_READY;
+ memset(&txbd->addr[1], 0, txbd->length);
+ }
+
+ /* set up rxbd for reception */
+ rxbd->status = BD_SC_EMPTY;
+ rxbd->length = size_to_expect;
+ rxbd->addr = datain;
+
+ txbd->status |= BD_I2C_TX_START;
+ if (flags & I2CF_STOP_COND)
+ {
+ txbd->status |= BD_SC_LAST | BD_SC_WRAP;
+ rxbd->status |= BD_SC_WRAP;
+ }
+
+ PRINTD(("[I2C] txbd: length=0x%04x status=0x%04x addr[0]=0x%02x addr[1]=0x%02x\n",
+ txbd->length,
+ txbd->status,
+ txbd->addr[0],
+ txbd->addr[1]));
+ PRINTD(("[I2C] rxbd: length=0x%04x status=0x%04x addr[0]=0x%02x addr[1]=0x%02x\n",
+ rxbd->length,
+ rxbd->status,
+ rxbd->addr[0],
+ rxbd->addr[1]));
+
+ /* advance state */
+ state->tx_buf += txbd->length;
+ state->tx_space -= txbd->length;
+ state->tx_idx++;
+ state->txbd = (void*)(txbd + 1);
+ state->rx_idx++;
+ state->rxbd = (void*)(rxbd + 1);
+
+ return 0;
+}
+
+
+static
+int i2c_doio(i2c_state_t *state)
+{
+ volatile immap_t *immap = (immap_t *)CFG_IMMR ;
+ volatile iic_t *iip;
+ volatile i2c8260_t *i2c = (i2c8260_t *)&immap->im_i2c;
+ volatile I2C_BD *txbd, *rxbd;
+ int j;
+ int timeout;
+ uint dpaddr;
+
+ PRINTD(("[I2C] i2c_doio\n"));
+
+ timeout = TOUT_LOOP * 256; /* arbitrarily long */
+
+ if (state->tx_idx <= 0 && state->rx_idx <= 0) {
+ PRINTD(("[I2C] No I/O is queued\n"));
+ return I2CERR_QUEUE_EMPTY;
+ }
+
+ dpaddr = *((unsigned short*)(&immap->im_dprambase[PROFF_I2C_BASE]));
+ iip = (iic_t *)&immap->im_dprambase[dpaddr];
+ iip->iic_rbptr = iip->iic_rbase;
+ iip->iic_tbptr = iip->iic_tbase;
+
+ /* Enable I2C */
+ PRINTD(("[I2C] Enabling I2C...\n"));
+ i2c->i2c_i2mod |= 0x01;
+
+ /* Begin transmission */
+ i2c->i2c_i2com |= 0x80;
+
+ /* Loop until transmit & receive completed */
+
+ txbd = ((I2C_BD*)state->txbd) - 1;
+ j = 0;
+ if (state->tx_idx > 0) {
+ timeout = TOUT_LOOP * txbd->length;
+
+ PRINTD(("[I2C] Transmitting...(txbd=0x%08lx)\n", (ulong)txbd));
+ udelay(START_DELAY_US); /* give it time to start */
+ while((txbd->status & BD_SC_READY) && (j++ < timeout)) {
+ udelay(DELAY_US);
+ if (ctrlc())
+ return (-1);
+ __asm__ __volatile__ ("eieio");
+ }
+ }
+
+ rxbd = ((I2C_BD*)state->rxbd) - 1;
+ j = 0;
+ if ((state->rx_idx > 0) && (j < timeout)) {
+ timeout = TOUT_LOOP * rxbd->length;
+ PRINTD(("[I2C] Receiving...(rxbd=0x%08lx)\n", (ulong)rxbd));
+ udelay(START_DELAY_US); /* give it time to start */
+ while((rxbd->status & BD_SC_EMPTY) && (j++ < timeout)) {
+ udelay(DELAY_US);
+ if (ctrlc())
+ return (-1);
+ __asm__ __volatile__ ("eieio");
+ }
+ }
+
+ /* Turn off I2C */
+ i2c->i2c_i2mod &= ~0x01;
+
+ if (state->err_cb != NULL) {
+ int n, i, b;
+
+ /*
+ * if we have an error callback function, look at the
+ * error bits in the bd status and pass them back
+ */
+
+ if ((n = state->tx_idx) > 0) {
+ for (i = 0; i < n; i++) {
+ txbd = ((I2C_BD*)state->txbd) - (n - i);
+ if ((b = txbd->status & BD_I2C_TX_ERR) != 0)
+ (*state->err_cb)(I2CECB_TX_ERR|b, i);
+ }
+ }
+
+ if ((n = state->rx_idx) > 0) {
+ for (i = 0; i < n; i++) {
+ rxbd = ((I2C_BD*)state->rxbd) - (n - i);
+ if ((b = rxbd->status & BD_I2C_RX_ERR) != 0)
+ (*state->err_cb)(I2CECB_RX_ERR|b, i);
+ }
+ }
+
+ if (j >= timeout)
+ (*state->err_cb)(I2CECB_TIMEOUT, 0);
+ }
+
+ /* sort out errors and return appropriate good/error status */
+ if(j >= timeout)
+ return(I2CERR_TIMEOUT);
+ if((txbd->status & BD_I2C_TX_ERR) != 0)
+ return(I2CECB_TX_ERR | (txbd->status & I2CECB_TX_MASK));
+ if((rxbd->status & BD_I2C_RX_ERR) != 0)
+ return(I2CECB_RX_ERR | (rxbd->status & I2CECB_RX_MASK));
+
+ return(0);
+}
+
+static int had_tx_nak;
+
+static void
+i2c_test_callback(int flags, int xnum)
+{
+ if ((flags & I2CECB_TX_ERR) && (flags & I2CECB_TX_NAK))
+ had_tx_nak = 1;
+}
+
+int i2c_probe(uchar chip)
+{
+ i2c_state_t state;
+ int rc;
+ uchar buf[1];
+
+ i2c_newio(&state);
+
+ state.err_cb = i2c_test_callback;
+ had_tx_nak = 0;
+
+ rc = i2c_receive(&state, chip, 0, I2CF_START_COND|I2CF_STOP_COND, 1, buf);
+
+ if (rc != 0)
+ return (rc);
+
+ rc = i2c_doio(&state);
+
+ if ((rc != 0) && (rc != I2CERR_TIMEOUT))
+ return (rc);
+
+ return (had_tx_nak);
+}
+
+
+int
+i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+ i2c_state_t state;
+ uchar xaddr[4];
+ int rc;
+
+ xaddr[0] = (addr >> 24) & 0xFF;
+ xaddr[1] = (addr >> 16) & 0xFF;
+ xaddr[2] = (addr >> 8) & 0xFF;
+ xaddr[3] = addr & 0xFF;
+
+#ifdef CFG_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)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
+#endif
+
+ i2c_newio(&state);
+
+ rc = i2c_send(&state, chip, 0, I2CF_START_COND, alen, &xaddr[4-alen]);
+ if (rc != 0) {
+ printf("i2c_read: i2c_send failed (%d)\n", rc);
+ return 1;
+ }
+
+ rc = i2c_receive(&state, chip, 0, I2CF_STOP_COND, len, buffer);
+ if (rc != 0) {
+ printf("i2c_read: i2c_receive failed (%d)\n", rc);
+ return 1;
+ }
+
+ rc = i2c_doio(&state);
+ if (rc != 0) {
+ printf("i2c_read: i2c_doio failed (%d)\n", rc);
+ return 1;
+ }
+ return 0;
+}
+
+int
+i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+ i2c_state_t state;
+ uchar xaddr[4];
+ int rc;
+
+ xaddr[0] = (addr >> 24) & 0xFF;
+ xaddr[1] = (addr >> 16) & 0xFF;
+ xaddr[2] = (addr >> 8) & 0xFF;
+ xaddr[3] = addr & 0xFF;
+
+#ifdef CFG_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)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
+#endif
+
+ i2c_newio(&state);
+
+ rc = i2c_send(&state, chip, 0, I2CF_START_COND, alen, &xaddr[4-alen]);
+ if (rc != 0) {
+ printf("i2c_write: first i2c_send failed (%d)\n", rc);
+ return 1;
+ }
+
+ rc = i2c_send(&state, 0, 0, I2CF_STOP_COND, len, buffer);
+ if (rc != 0) {
+ printf("i2c_write: second i2c_send failed (%d)\n", rc);
+ return 1;
+ }
+
+ rc = i2c_doio(&state);
+ if (rc != 0) {
+ printf("i2c_write: i2c_doio failed (%d)\n", rc);
+ return 1;
+ }
+ return 0;
+}
+
+uchar
+i2c_reg_read(uchar chip, uchar reg)
+{
+ char buf;
+
+ i2c_read(chip, reg, 1, &buf, 1);
+
+ return (buf);
+}
+
+void
+i2c_reg_write(uchar chip, uchar reg, uchar val)
+{
+ i2c_write(chip, reg, 1, &val, 1);
+}
+
+#endif /* CONFIG_HARD_I2C */