summaryrefslogtreecommitdiff
path: root/arch/powerpc/cpu/mpc8xx/i2c.c
diff options
context:
space:
mode:
authorStefan Roese <sr@denx.de>2010-04-15 16:07:28 +0200
committerWolfgang Denk <wd@denx.de>2010-04-21 23:42:38 +0200
commita47a12becf66f02a56da91c161e2edb625e9f20c (patch)
tree6efae7137d26d1e610c5fd56b7aaa3c043ad2b71 /arch/powerpc/cpu/mpc8xx/i2c.c
parent254ab7bd464657600aba69d840406f9358f3e116 (diff)
Move arch/ppc to arch/powerpc
As discussed on the list, move "arch/ppc" to "arch/powerpc" to better match the Linux directory structure. Please note that this patch also changes the "ppc" target in MAKEALL to "powerpc" to match this new infrastructure. But "ppc" is kept as an alias for now, to not break compatibility with scripts using this name. Signed-off-by: Stefan Roese <sr@denx.de> Acked-by: Wolfgang Denk <wd@denx.de> Acked-by: Detlev Zundel <dzu@denx.de> Acked-by: Kim Phillips <kim.phillips@freescale.com> Cc: Peter Tyser <ptyser@xes-inc.com> Cc: Anatolij Gustschin <agust@denx.de>
Diffstat (limited to 'arch/powerpc/cpu/mpc8xx/i2c.c')
-rw-r--r--arch/powerpc/cpu/mpc8xx/i2c.c707
1 files changed, 707 insertions, 0 deletions
diff --git a/arch/powerpc/cpu/mpc8xx/i2c.c b/arch/powerpc/cpu/mpc8xx/i2c.c
new file mode 100644
index 0000000000..338cababe8
--- /dev/null
+++ b/arch/powerpc/cpu/mpc8xx/i2c.c
@@ -0,0 +1,707 @@
+/*
+ * (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
+ *
+ * Back ported to the 8xx platform (from the 8260 platform) by
+ * Murray.Jensen@cmst.csiro.au, 27-Jan-01.
+ */
+
+#include <common.h>
+
+#ifdef CONFIG_HARD_I2C
+
+#include <commproc.h>
+#include <i2c.h>
+#ifdef CONFIG_LWMON
+#include <watchdog.h>
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* define to enable debug messages */
+#undef DEBUG_I2C
+
+/* tx/rx timeout (we need the i2c early, so we don't use get_timer()) */
+#define TOUT_LOOP 1000000
+
+#define NUM_RX_BDS 4
+#define NUM_TX_BDS 4
+#define MAX_TX_SPACE 256
+#define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
+
+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
+
+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 */
+
+#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 + 1) / 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;
+
+ 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 *) CONFIG_SYS_IMMR;
+ volatile i2c8xx_t *i2c = (i2c8xx_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 slaveaddr)
+{
+ volatile immap_t *immap = (immap_t *)CONFIG_SYS_IMMR ;
+ volatile cpm8xx_t *cp = (cpm8xx_t *)&immap->im_cpm;
+ volatile i2c8xx_t *i2c = (i2c8xx_t *)&immap->im_i2c;
+ volatile iic_t *iip = (iic_t *)&cp->cp_dparam[PROFF_IIC];
+ ulong rbase, tbase;
+ volatile I2C_BD *rxbd, *txbd;
+ uint dpaddr;
+
+#ifdef 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();
+#endif
+
+#ifdef CONFIG_SYS_I2C_UCODE_PATCH
+ iip = (iic_t *)&cp->cp_dpmem[iip->iic_rpbase];
+#else
+ /* Disable relocation */
+ iip->iic_rpbase = 0;
+#endif
+
+#ifdef CONFIG_SYS_ALLOC_DPRAM
+ dpaddr = iip->iic_rbase;
+ if (dpaddr == 0) {
+ /* need to allocate dual port ram */
+ dpaddr = dpram_alloc_align(
+ (NUM_RX_BDS * sizeof(I2C_BD)) + (NUM_TX_BDS * sizeof(I2C_BD)) +
+ MAX_TX_SPACE, 8);
+ }
+#else
+ dpaddr = CPM_I2C_BASE;
+#endif
+
+ /*
+ * initialise data in dual port ram:
+ *
+ * dpaddr->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)
+ */
+
+ rbase = dpaddr;
+ tbase = rbase + NUM_RX_BDS * sizeof(I2C_BD);
+
+ /* Initialize Port B I2C pins. */
+ cp->cp_pbpar |= 0x00000030;
+ cp->cp_pbdir |= 0x00000030;
+ cp->cp_pbodr |= 0x00000030;
+
+ /* Disable interrupts */
+ i2c->i2c_i2mod = 0x00;
+ i2c->i2c_i2cmr = 0x00;
+ i2c->i2c_i2cer = 0xff;
+ i2c->i2c_i2add = slaveaddr;
+
+ /*
+ * 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->cpu_clk, CONFIG_SYS_I2C_SPEED) ;
+
+ /* Set I2C controller in master mode */
+ i2c->i2c_i2com = 0x01;
+
+ /* Set SDMA bus arbitration level to 5 (SDCR) */
+ immap->im_siu_conf.sc_sdcr = 0x0001 ;
+
+ /* Initialize Tx/Rx parameters */
+ iip->iic_rbase = rbase;
+ iip->iic_tbase = tbase;
+ rxbd = (I2C_BD *)((unsigned char *)&cp->cp_dpmem[iip->iic_rbase]);
+ txbd = (I2C_BD *)((unsigned char *)&cp->cp_dpmem[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;
+
+#ifdef CONFIG_SYS_I2C_UCODE_PATCH
+ /*
+ * Initialize required parameters if using microcode patch.
+ */
+ iip->iic_rbptr = iip->iic_rbase;
+ iip->iic_tbptr = iip->iic_tbase;
+ iip->iic_rstate = 0;
+ iip->iic_tstate = 0;
+#else
+ cp->cp_cpcr = mk_cr_cmd(CPM_CR_CH_I2C, CPM_CR_INIT_TRX) | CPM_CR_FLG;
+ do {
+ __asm__ __volatile__ ("eieio");
+ } while (cp->cp_cpcr & CPM_CR_FLG);
+#endif
+
+ /* 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 *)CONFIG_SYS_IMMR ;
+ volatile cpm8xx_t *cp = (cpm8xx_t *)&immap->im_cpm;
+ volatile iic_t *iip = (iic_t *)&cp->cp_dparam[PROFF_IIC];
+
+ PRINTD(("[I2C] i2c_newio\n"));
+
+#ifdef CONFIG_SYS_I2C_UCODE_PATCH
+ iip = (iic_t *)&cp->cp_dpmem[iip->iic_rpbase];
+#endif
+ state->rx_idx = 0;
+ state->tx_idx = 0;
+ state->rxbd = (void*)&cp->cp_dpmem[iip->iic_rbase];
+ state->txbd = (void*)&cp->cp_dpmem[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 msg + dest addr */
+ txbd->addr[0] = address << 1;
+ txbd->addr[1] = secondary_address;
+ i = 2;
+ } else {
+ txbd->length = size + 1; /* Length of msg + dest addr */
+ txbd->addr[0] = address << 1; /* Write dest addr 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 *)CONFIG_SYS_IMMR ;
+ volatile cpm8xx_t *cp = (cpm8xx_t *)&immap->im_cpm;
+ volatile i2c8xx_t *i2c = (i2c8xx_t *)&immap->im_i2c;
+ volatile iic_t *iip = (iic_t *)&cp->cp_dparam[PROFF_IIC];
+ volatile I2C_BD *txbd, *rxbd;
+ volatile int j = 0;
+
+ PRINTD(("[I2C] i2c_doio\n"));
+
+#ifdef CONFIG_SYS_I2C_UCODE_PATCH
+ iip = (iic_t *)&cp->cp_dpmem[iip->iic_rpbase];
+#endif
+
+ if (state->tx_idx <= 0 && state->rx_idx <= 0) {
+ PRINTD(("[I2C] No I/O is queued\n"));
+ return I2CERR_QUEUE_EMPTY;
+ }
+
+ 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 */
+
+ if (state->tx_idx > 0) {
+ txbd = ((I2C_BD*)state->txbd) - 1;
+ PRINTD(("[I2C] Transmitting...(txbd=0x%08lx)\n", (ulong)txbd));
+ while((txbd->status & BD_SC_READY) && (j++ < TOUT_LOOP)) {
+ if (ctrlc()) {
+ return (-1);
+ }
+ __asm__ __volatile__ ("eieio");
+ }
+ }
+
+ if ((state->rx_idx > 0) && (j < TOUT_LOOP)) {
+ rxbd = ((I2C_BD*)state->rxbd) - 1;
+ PRINTD(("[I2C] Receiving...(rxbd=0x%08lx)\n", (ulong)rxbd));
+ while((rxbd->status & BD_SC_EMPTY) && (j++ < TOUT_LOOP)) {
+ 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 >= TOUT_LOOP)
+ (*state->err_cb)(I2CECB_TIMEOUT, 0);
+ }
+
+ return (j >= TOUT_LOOP) ? I2CERR_TIMEOUT : 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_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
+
+ 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;
+
+#ifdef CONFIG_LWMON
+ WATCHDOG_RESET();
+#endif
+
+ xaddr[0] = (addr >> 24) & 0xFF;
+ xaddr[1] = (addr >> 16) & 0xFF;
+ xaddr[2] = (addr >> 8) & 0xFF;
+ xaddr[3] = addr & 0xFF;
+
+#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);
+#endif
+
+ i2c_newio(&state);
+
+ rc = i2c_send(&state, chip, 0, I2CF_START_COND, alen, &xaddr[4-alen]);
+ if (rc != 0) {
+ if (gd->have_console)
+ 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) {
+ if (gd->have_console)
+ printf("i2c_read: i2c_receive failed (%d)\n", rc);
+ return 1;
+ }
+
+ rc = i2c_doio(&state);
+ if (rc != 0) {
+ if (gd->have_console)
+ 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 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);
+#endif
+
+ i2c_newio(&state);
+
+ rc = i2c_send(&state, chip, 0, I2CF_START_COND, alen, &xaddr[4-alen]);
+ if (rc != 0) {
+ if (gd->have_console)
+ 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) {
+ if (gd->have_console)
+ printf("i2c_write: second i2c_send failed (%d)\n", rc);
+ return 1;
+ }
+
+ rc = i2c_doio(&state);
+ if (rc != 0) {
+ if (gd->have_console)
+ printf("i2c_write: i2c_doio failed (%d)\n", rc);
+ return 1;
+ }
+ return 0;
+}
+
+#endif /* CONFIG_HARD_I2C */