]> git.sur5r.net Git - u-boot/blobdiff - drivers/i2c/omap24xx_i2c.c
i2c: UniPhier: add driver for UniPhier i2c controller
[u-boot] / drivers / i2c / omap24xx_i2c.c
index 7dab78685dfb44102295a2cf138d49f48118b9ac..0f1e35c460ca375aa517dcb4a9d098927ef91d37 100644 (file)
  *
  * Adapted for OMAP2420 I2C, r-woodruff2@ti.com
  *
+ * Copyright (c) 2013 Lubomir Popov <lpopov@mm-sol.com>, MM Solutions
+ * New i2c_read, i2c_write and i2c_probe functions, tested on OMAP4
+ * (4430/60/70), OMAP5 (5430) and AM335X (3359); should work on older
+ * OMAPs and derivatives as well. The only anticipated exception would
+ * be the OMAP2420, which shall require driver modification.
+ * - Rewritten i2c_read to operate correctly with all types of chips
+ *   (old function could not read consistent data from some I2C slaves).
+ * - Optimized i2c_write.
+ * - New i2c_probe, performs write access vs read. The old probe could
+ *   hang the system under certain conditions (e.g. unconfigured pads).
+ * - The read/write/probe functions try to identify unconfigured bus.
+ * - Status functions now read irqstatus_raw as per TRM guidelines
+ *   (except for OMAP243X and OMAP34XX).
+ * - Driver now supports up to I2C5 (OMAP5).
+ *
+ * Copyright (c) 2014 Hannes Petermaier <oe5hpm@oevsv.at>, B&R
+ * - Added support for set_speed
+ *
  */
 
 #include <common.h>
-
-#ifdef CONFIG_DRIVER_OMAP24XX_I2C
+#include <i2c.h>
 
 #include <asm/arch/i2c.h>
 #include <asm/io.h>
 
-#define inw(a) __raw_readw(a)
-#define outw(a,v) __raw_writew(a,v)
+#include "omap24xx_i2c.h"
 
-static void wait_for_bb (void);
-static u16 wait_for_pin (void);
-static void flush_fifo(void);
+DECLARE_GLOBAL_DATA_PTR;
 
-void i2c_init (int speed, int slaveadd)
-{
-       u16 scl;
+#define I2C_TIMEOUT    1000
 
-       outw(0x2, I2C_SYSC); /* for ES2 after soft reset */
-       udelay(1000);
-       outw(0x0, I2C_SYSC); /* will probably self clear but */
+/* Absolutely safe for status update at 100 kHz I2C: */
+#define I2C_WAIT       200
 
-       if (inw (I2C_CON) & I2C_CON_EN) {
-               outw (0, I2C_CON);
-               udelay (50000);
+static int wait_for_bb(struct i2c_adapter *adap);
+static struct i2c *omap24_get_base(struct i2c_adapter *adap);
+static u16 wait_for_event(struct i2c_adapter *adap);
+static void flush_fifo(struct i2c_adapter *adap);
+static int omap24_i2c_findpsc(u32 *pscl, u32 *psch, uint speed)
+{
+       unsigned int sampleclk, prescaler;
+       int fsscll, fssclh;
+
+       speed <<= 1;
+       prescaler = 0;
+       /*
+        * some divisors may cause a precission loss, but shouldn't
+        * be a big thing, because i2c_clk is then allready very slow.
+        */
+       while (prescaler <= 0xFF) {
+               sampleclk = I2C_IP_CLK / (prescaler+1);
+
+               fsscll = sampleclk / speed;
+               fssclh = fsscll;
+               fsscll -= I2C_FASTSPEED_SCLL_TRIM;
+               fssclh -= I2C_FASTSPEED_SCLH_TRIM;
+
+               if (((fsscll > 0) && (fssclh > 0)) &&
+                   ((fsscll <= (255-I2C_FASTSPEED_SCLL_TRIM)) &&
+                   (fssclh <= (255-I2C_FASTSPEED_SCLH_TRIM)))) {
+                       if (pscl)
+                               *pscl = fsscll;
+                       if (psch)
+                               *psch = fssclh;
+
+                       return prescaler;
+               }
+               prescaler++;
        }
-
-       /* 12Mhz I2C module clock */
-       outw (0, I2C_PSC);
-       speed = speed/1000;                 /* 100 or 400 */
-       scl = ((12000/(speed*2)) - 7);  /* use 7 when PSC = 0 */
-       outw (scl, I2C_SCLL);
-       outw (scl, I2C_SCLH);
-       /* own address */
-       outw (slaveadd, I2C_OA);
-       outw (I2C_CON_EN, I2C_CON);
-
-       /* have to enable intrrupts or OMAP i2c module doesn't work */
-       outw (I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
-             I2C_IE_NACK_IE | I2C_IE_AL_IE, I2C_IE);
-       udelay (1000);
-       flush_fifo();
-       outw (0xFFFF, I2C_STAT);
-       outw (0, I2C_CNT);
+       return -1;
 }
-
-static int i2c_read_byte (u8 devaddr, u8 regoffset, u8 * value)
+static uint omap24_i2c_setspeed(struct i2c_adapter *adap, uint speed)
 {
-       int i2c_error = 0;
-       u16 status;
-
-       /* wait until bus not busy */
-       wait_for_bb ();
+       struct i2c *i2c_base = omap24_get_base(adap);
+       int psc, fsscll = 0, fssclh = 0;
+       int hsscll = 0, hssclh = 0;
+       u32 scll = 0, sclh = 0;
+
+       if (speed >= OMAP_I2C_HIGH_SPEED) {
+               /* High speed */
+               psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK;
+               psc -= 1;
+               if (psc < I2C_PSC_MIN) {
+                       printf("Error : I2C unsupported prescaler %d\n", psc);
+                       return -1;
+               }
 
-       /* one byte only */
-       outw (1, I2C_CNT);
-       /* set slave address */
-       outw (devaddr, I2C_SA);
-       /* no stop bit needed here */
-       outw (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX, I2C_CON);
+               /* For first phase of HS mode */
+               fsscll = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
 
-       status = wait_for_pin ();
+               fssclh = fsscll;
 
-       if (status & I2C_STAT_XRDY) {
-               /* Important: have to use byte access */
-               *(volatile u8 *) (I2C_DATA) = regoffset;
-               udelay (20000);
-               if (inw (I2C_STAT) & I2C_STAT_NACK) {
-                       i2c_error = 1;
+               fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM;
+               fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
+               if (((fsscll < 0) || (fssclh < 0)) ||
+                   ((fsscll > 255) || (fssclh > 255))) {
+                       puts("Error : I2C initializing first phase clock\n");
+                       return -1;
                }
-       } else {
-               i2c_error = 1;
-       }
 
-       if (!i2c_error) {
-               /* free bus, otherwise we can't use a combined transction */
-               outw (0, I2C_CON);
-               while (inw (I2C_STAT) || (inw (I2C_CON) & I2C_CON_MST)) {
-                       udelay (10000);
-                       /* Have to clear pending interrupt to clear I2C_STAT */
-                       outw (0xFFFF, I2C_STAT);
+               /* For second phase of HS mode */
+               hsscll = hssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
+
+               hsscll -= I2C_HIGHSPEED_PHASE_TWO_SCLL_TRIM;
+               hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
+               if (((fsscll < 0) || (fssclh < 0)) ||
+                   ((fsscll > 255) || (fssclh > 255))) {
+                       puts("Error : I2C initializing second phase clock\n");
+                       return -1;
                }
 
-               wait_for_bb ();
-               /* set slave address */
-               outw (devaddr, I2C_SA);
-               /* read one byte from slave */
-               outw (1, I2C_CNT);
-               /* need stop bit here */
-               outw (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP,
-                     I2C_CON);
+               scll = (unsigned int)hsscll << 8 | (unsigned int)fsscll;
+               sclh = (unsigned int)hssclh << 8 | (unsigned int)fssclh;
 
-               status = wait_for_pin ();
-               if (status & I2C_STAT_RRDY) {
-                       *value = inw (I2C_DATA);
-                       udelay (20000);
-               } else {
-                       i2c_error = 1;
+       } else {
+               /* Standard and fast speed */
+               psc = omap24_i2c_findpsc(&scll, &sclh, speed);
+               if (0 > psc) {
+                       puts("Error : I2C initializing clock\n");
+                       return -1;
                }
+       }
 
-               if (!i2c_error) {
-                       outw (I2C_CON_EN, I2C_CON);
-                       while (inw (I2C_STAT)
-                              || (inw (I2C_CON) & I2C_CON_MST)) {
-                               udelay (10000);
-                               outw (0xFFFF, I2C_STAT);
-                       }
-               }
+       adap->speed     = speed;
+       adap->waitdelay = (10000000 / speed) * 2; /* wait for 20 clkperiods */
+       writew(0, &i2c_base->con);
+       writew(psc, &i2c_base->psc);
+       writew(scll, &i2c_base->scll);
+       writew(sclh, &i2c_base->sclh);
+       writew(I2C_CON_EN, &i2c_base->con);
+       writew(0xFFFF, &i2c_base->stat);        /* clear all pending status */
+
+       return 0;
+}
+
+static void omap24_i2c_deblock(struct i2c_adapter *adap)
+{
+       struct i2c *i2c_base = omap24_get_base(adap);
+       int i;
+       u16 systest;
+       u16 orgsystest;
+
+       /* set test mode ST_EN = 1 */
+       orgsystest = readw(&i2c_base->systest);
+       systest = orgsystest;
+       /* enable testmode */
+       systest |= I2C_SYSTEST_ST_EN;
+       writew(systest, &i2c_base->systest);
+       systest &= ~I2C_SYSTEST_TMODE_MASK;
+       systest |= 3 << I2C_SYSTEST_TMODE_SHIFT;
+       writew(systest, &i2c_base->systest);
+
+       /* set SCL, SDA  = 1 */
+       systest |= I2C_SYSTEST_SCL_O | I2C_SYSTEST_SDA_O;
+       writew(systest, &i2c_base->systest);
+       udelay(10);
+
+       /* toggle scl 9 clocks */
+       for (i = 0; i < 9; i++) {
+               /* SCL = 0 */
+               systest &= ~I2C_SYSTEST_SCL_O;
+               writew(systest, &i2c_base->systest);
+               udelay(10);
+               /* SCL = 1 */
+               systest |= I2C_SYSTEST_SCL_O;
+               writew(systest, &i2c_base->systest);
+               udelay(10);
        }
-       flush_fifo();
-       outw (0xFFFF, I2C_STAT);
-       outw (0, I2C_CNT);
-       return i2c_error;
+
+       /* send stop */
+       systest &= ~I2C_SYSTEST_SDA_O;
+       writew(systest, &i2c_base->systest);
+       udelay(10);
+       systest |= I2C_SYSTEST_SCL_O | I2C_SYSTEST_SDA_O;
+       writew(systest, &i2c_base->systest);
+       udelay(10);
+
+       /* restore original mode */
+       writew(orgsystest, &i2c_base->systest);
 }
 
-static int i2c_write_byte (u8 devaddr, u8 regoffset, u8 value)
+static void omap24_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
 {
-       int i2c_error = 0;
-       u16 status, stat;
-
-       /* wait until bus not busy */
-       wait_for_bb ();
-
-       /* two bytes */
-       outw (2, I2C_CNT);
-       /* set slave address */
-       outw (devaddr, I2C_SA);
-       /* stop bit needed here */
-       outw (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
-             I2C_CON_STP, I2C_CON);
-
-       /* wait until state change */
-       status = wait_for_pin ();
-
-       if (status & I2C_STAT_XRDY) {
-               /* send out two bytes */
-               outw ((value << 8) + regoffset, I2C_DATA);
-               /* must have enough delay to allow BB bit to go low */
-               udelay (50000);
-               if (inw (I2C_STAT) & I2C_STAT_NACK) {
-                       i2c_error = 1;
-               }
-       } else {
-               i2c_error = 1;
+       struct i2c *i2c_base = omap24_get_base(adap);
+       int timeout = I2C_TIMEOUT;
+       int deblock = 1;
+
+retry:
+       if (readw(&i2c_base->con) & I2C_CON_EN) {
+               writew(0, &i2c_base->con);
+               udelay(50000);
        }
 
-       if (!i2c_error) {
-               int eout = 200;
+       writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
+       udelay(1000);
 
-               outw (I2C_CON_EN, I2C_CON);
-               while ((stat = inw (I2C_STAT)) || (inw (I2C_CON) & I2C_CON_MST)) {
-                       udelay (1000);
-                       /* have to read to clear intrrupt */
-                       outw (0xFFFF, I2C_STAT);
-                       if(--eout == 0) /* better leave with error than hang */
-                               break;
+       writew(I2C_CON_EN, &i2c_base->con);
+       while (!(readw(&i2c_base->syss) & I2C_SYSS_RDONE) && timeout--) {
+               if (timeout <= 0) {
+                       puts("ERROR: Timeout in soft-reset\n");
+                       return;
                }
+               udelay(1000);
        }
-       flush_fifo();
-       outw (0xFFFF, I2C_STAT);
-       outw (0, I2C_CNT);
-       return i2c_error;
+
+       if (0 != omap24_i2c_setspeed(adap, speed)) {
+               printf("ERROR: failed to setup I2C bus-speed!\n");
+               return;
+       }
+
+       /* own address */
+       writew(slaveadd, &i2c_base->oa);
+
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+       /*
+        * Have to enable interrupts for OMAP2/3, these IPs don't have
+        * an 'irqstatus_raw' register and we shall have to poll 'stat'
+        */
+       writew(I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
+              I2C_IE_NACK_IE | I2C_IE_AL_IE, &i2c_base->ie);
+#endif
+       udelay(1000);
+       flush_fifo(adap);
+       writew(0xFFFF, &i2c_base->stat);
+
+       /* Handle possible failed I2C state */
+       if (wait_for_bb(adap))
+               if (deblock == 1) {
+                       omap24_i2c_deblock(adap);
+                       deblock = 0;
+                       goto retry;
+               }
 }
 
-static void flush_fifo(void)
-{      u16 stat;
+static void flush_fifo(struct i2c_adapter *adap)
+{
+       struct i2c *i2c_base = omap24_get_base(adap);
+       u16 stat;
 
-       /* note: if you try and read data when its not there or ready
+       /*
+        * note: if you try and read data when its not there or ready
         * you get a bus error
         */
-       while(1){
-               stat = inw(I2C_STAT);
-               if(stat == I2C_STAT_RRDY){
-                       inw(I2C_DATA);
-                       outw(I2C_STAT_RRDY,I2C_STAT);
+       while (1) {
+               stat = readw(&i2c_base->stat);
+               if (stat == I2C_STAT_RRDY) {
+                       readb(&i2c_base->data);
+                       writew(I2C_STAT_RRDY, &i2c_base->stat);
                        udelay(1000);
-               }else
+               } else
                        break;
        }
 }
 
-int i2c_probe (uchar chip)
+/*
+ * i2c_probe: Use write access. Allows to identify addresses that are
+ *            write-only (like the config register of dual-port EEPROMs)
+ */
+static int omap24_i2c_probe(struct i2c_adapter *adap, uchar chip)
 {
+       struct i2c *i2c_base = omap24_get_base(adap);
+       u16 status;
        int res = 1; /* default = fail */
 
-       if (chip == inw (I2C_OA)) {
+       if (chip == readw(&i2c_base->oa))
+               return res;
+
+       /* Wait until bus is free */
+       if (wait_for_bb(adap))
                return res;
+
+       /* No data transfer, slave addr only */
+       writew(chip, &i2c_base->sa);
+       /* Stop bit needed here */
+       writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
+              I2C_CON_STP, &i2c_base->con);
+
+       status = wait_for_event(adap);
+
+       if ((status & ~I2C_STAT_XRDY) == 0 || (status & I2C_STAT_AL)) {
+               /*
+                * With current high-level command implementation, notifying
+                * the user shall flood the console with 127 messages. If
+                * silent exit is desired upon unconfigured bus, remove the
+                * following 'if' section:
+                */
+               if (status == I2C_STAT_XRDY)
+                       printf("i2c_probe: pads on bus %d probably not configured (status=0x%x)\n",
+                              adap->hwadapnr, status);
+
+               goto pr_exit;
        }
 
-       /* wait until bus not busy */
-       wait_for_bb ();
-
-       /* try to read one byte */
-       outw (1, I2C_CNT);
-       /* set slave address */
-       outw (chip, I2C_SA);
-       /* stop bit needed here */
-       outw (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP, I2C_CON);
-       /* enough delay for the NACK bit set */
-       udelay (50000);
-
-       if (!(inw (I2C_STAT) & I2C_STAT_NACK)) {
-               res = 0;      /* success case */
-               flush_fifo();
-               outw(0xFFFF, I2C_STAT);
-       } else {
-               outw(0xFFFF, I2C_STAT);  /* failue, clear sources*/
-               outw (inw (I2C_CON) | I2C_CON_STP, I2C_CON); /* finish up xfer */
-               udelay(20000);
-               wait_for_bb ();
+       /* Check for ACK (!NAK) */
+       if (!(status & I2C_STAT_NACK)) {
+               res = 0;                                /* Device found */
+               udelay(adap->waitdelay);/* Required by AM335X in SPL */
+               /* Abort transfer (force idle state) */
+               writew(I2C_CON_MST | I2C_CON_TRX, &i2c_base->con); /* Reset */
+               udelay(1000);
+               writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_TRX |
+                      I2C_CON_STP, &i2c_base->con);            /* STP */
        }
-       flush_fifo();
-       outw (0, I2C_CNT); /* don't allow any more data in...we don't want it.*/
-       outw(0xFFFF, I2C_STAT);
+pr_exit:
+       flush_fifo(adap);
+       writew(0xFFFF, &i2c_base->stat);
        return res;
 }
 
-int i2c_read (uchar chip, uint addr, int alen, uchar * buffer, int len)
+/*
+ * i2c_read: Function now uses a single I2C read transaction with bulk transfer
+ *           of the requested number of bytes (note that the 'i2c md' command
+ *           limits this to 16 bytes anyway). If CONFIG_I2C_REPEATED_START is
+ *           defined in the board config header, this transaction shall be with
+ *           Repeated Start (Sr) between the address and data phases; otherwise
+ *           Stop-Start (P-S) shall be used (some I2C chips do require a P-S).
+ *           The address (reg offset) may be 0, 1 or 2 bytes long.
+ *           Function now reads correctly from chips that return more than one
+ *           byte of data per addressed register (like TI temperature sensors),
+ *           or that do not need a register address at all (such as some clock
+ *           distributors).
+ */
+static int omap24_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
+                          int alen, uchar *buffer, int len)
 {
-       int i;
+       struct i2c *i2c_base = omap24_get_base(adap);
+       int i2c_error = 0;
+       u16 status;
 
-       if (alen > 1) {
-               printf ("I2C read: addr len %d not supported\n", alen);
+       if (alen < 0) {
+               puts("I2C read: addr len < 0\n");
+               return 1;
+       }
+       if (len < 0) {
+               puts("I2C read: data len < 0\n");
+               return 1;
+       }
+       if (buffer == NULL) {
+               puts("I2C read: NULL pointer passed\n");
                return 1;
        }
 
-       if (addr + len > 256) {
-               printf ("I2C read: address out of range\n");
+       if (alen > 2) {
+               printf("I2C read: addr len %d not supported\n", alen);
                return 1;
        }
 
-       for (i = 0; i < len; i++) {
-               if (i2c_read_byte (chip, addr + i, &buffer[i])) {
-                       printf ("I2C read: I/O error\n");
-                       i2c_init (CFG_I2C_SPEED, CFG_I2C_SLAVE);
-                       return 1;
+       if (addr + len > (1 << 16)) {
+               puts("I2C read: address out of range\n");
+               return 1;
+       }
+
+       /* Wait until bus not busy */
+       if (wait_for_bb(adap))
+               return 1;
+
+       /* Zero, one or two bytes reg address (offset) */
+       writew(alen, &i2c_base->cnt);
+       /* Set slave address */
+       writew(chip, &i2c_base->sa);
+
+       if (alen) {
+               /* Must write reg offset first */
+#ifdef CONFIG_I2C_REPEATED_START
+               /* No stop bit, use Repeated Start (Sr) */
+               writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
+                      I2C_CON_TRX, &i2c_base->con);
+#else
+               /* Stop - Start (P-S) */
+               writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP |
+                      I2C_CON_TRX, &i2c_base->con);
+#endif
+               /* Send register offset */
+               while (1) {
+                       status = wait_for_event(adap);
+                       /* Try to identify bus that is not padconf'd for I2C */
+                       if (status == I2C_STAT_XRDY) {
+                               i2c_error = 2;
+                               printf("i2c_read (addr phase): pads on bus %d probably not configured (status=0x%x)\n",
+                                      adap->hwadapnr, status);
+                               goto rd_exit;
+                       }
+                       if (status == 0 || (status & I2C_STAT_NACK)) {
+                               i2c_error = 1;
+                               printf("i2c_read: error waiting for addr ACK (status=0x%x)\n",
+                                      status);
+                               goto rd_exit;
+                       }
+                       if (alen) {
+                               if (status & I2C_STAT_XRDY) {
+                                       alen--;
+                                       /* Do we have to use byte access? */
+                                       writeb((addr >> (8 * alen)) & 0xff,
+                                              &i2c_base->data);
+                                       writew(I2C_STAT_XRDY, &i2c_base->stat);
+                               }
+                       }
+                       if (status & I2C_STAT_ARDY) {
+                               writew(I2C_STAT_ARDY, &i2c_base->stat);
+                               break;
+                       }
+               }
+       }
+       /* Set slave address */
+       writew(chip, &i2c_base->sa);
+       /* Read len bytes from slave */
+       writew(len, &i2c_base->cnt);
+       /* Need stop bit here */
+       writew(I2C_CON_EN | I2C_CON_MST |
+              I2C_CON_STT | I2C_CON_STP,
+              &i2c_base->con);
+
+       /* Receive data */
+       while (1) {
+               status = wait_for_event(adap);
+               /*
+                * Try to identify bus that is not padconf'd for I2C. This
+                * state could be left over from previous transactions if
+                * the address phase is skipped due to alen=0.
+                */
+               if (status == I2C_STAT_XRDY) {
+                       i2c_error = 2;
+                       printf("i2c_read (data phase): pads on bus %d probably not configured (status=0x%x)\n",
+                              adap->hwadapnr, status);
+                       goto rd_exit;
+               }
+               if (status == 0 || (status & I2C_STAT_NACK)) {
+                       i2c_error = 1;
+                       goto rd_exit;
+               }
+               if (status & I2C_STAT_RRDY) {
+                       *buffer++ = readb(&i2c_base->data);
+                       writew(I2C_STAT_RRDY, &i2c_base->stat);
+               }
+               if (status & I2C_STAT_ARDY) {
+                       writew(I2C_STAT_ARDY, &i2c_base->stat);
+                       break;
                }
        }
 
-       return 0;
+rd_exit:
+       flush_fifo(adap);
+       writew(0xFFFF, &i2c_base->stat);
+       return i2c_error;
 }
 
-int i2c_write (uchar chip, uint addr, int alen, uchar * buffer, int len)
+/* i2c_write: Address (reg offset) may be 0, 1 or 2 bytes long. */
+static int omap24_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
+                           int alen, uchar *buffer, int len)
 {
+       struct i2c *i2c_base = omap24_get_base(adap);
        int i;
+       u16 status;
+       int i2c_error = 0;
+       int timeout = I2C_TIMEOUT;
 
-       if (alen > 1) {
-               printf ("I2C read: addr len %d not supported\n", alen);
+       if (alen < 0) {
+               puts("I2C write: addr len < 0\n");
                return 1;
        }
 
-       if (addr + len > 256) {
-               printf ("I2C read: address out of range\n");
+       if (len < 0) {
+               puts("I2C write: data len < 0\n");
                return 1;
        }
 
+       if (buffer == NULL) {
+               puts("I2C write: NULL pointer passed\n");
+               return 1;
+       }
+
+       if (alen > 2) {
+               printf("I2C write: addr len %d not supported\n", alen);
+               return 1;
+       }
+
+       if (addr + len > (1 << 16)) {
+               printf("I2C write: address 0x%x + 0x%x out of range\n",
+                      addr, len);
+               return 1;
+       }
+
+       /* Wait until bus not busy */
+       if (wait_for_bb(adap))
+               return 1;
+
+       /* Start address phase - will write regoffset + len bytes data */
+       writew(alen + len, &i2c_base->cnt);
+       /* Set slave address */
+       writew(chip, &i2c_base->sa);
+       /* Stop bit needed here */
+       writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
+              I2C_CON_STP, &i2c_base->con);
+
+       while (alen) {
+               /* Must write reg offset (one or two bytes) */
+               status = wait_for_event(adap);
+               /* Try to identify bus that is not padconf'd for I2C */
+               if (status == I2C_STAT_XRDY) {
+                       i2c_error = 2;
+                       printf("i2c_write: pads on bus %d probably not configured (status=0x%x)\n",
+                              adap->hwadapnr, status);
+                       goto wr_exit;
+               }
+               if (status == 0 || (status & I2C_STAT_NACK)) {
+                       i2c_error = 1;
+                       printf("i2c_write: error waiting for addr ACK (status=0x%x)\n",
+                              status);
+                       goto wr_exit;
+               }
+               if (status & I2C_STAT_XRDY) {
+                       alen--;
+                       writeb((addr >> (8 * alen)) & 0xff, &i2c_base->data);
+                       writew(I2C_STAT_XRDY, &i2c_base->stat);
+               } else {
+                       i2c_error = 1;
+                       printf("i2c_write: bus not ready for addr Tx (status=0x%x)\n",
+                              status);
+                       goto wr_exit;
+               }
+       }
+       /* Address phase is over, now write data */
        for (i = 0; i < len; i++) {
-               if (i2c_write_byte (chip, addr + i, buffer[i])) {
-                       printf ("I2C read: I/O error\n");
-                       i2c_init (CFG_I2C_SPEED, CFG_I2C_SLAVE);
-                       return 1;
+               status = wait_for_event(adap);
+               if (status == 0 || (status & I2C_STAT_NACK)) {
+                       i2c_error = 1;
+                       printf("i2c_write: error waiting for data ACK (status=0x%x)\n",
+                              status);
+                       goto wr_exit;
+               }
+               if (status & I2C_STAT_XRDY) {
+                       writeb(buffer[i], &i2c_base->data);
+                       writew(I2C_STAT_XRDY, &i2c_base->stat);
+               } else {
+                       i2c_error = 1;
+                       printf("i2c_write: bus not ready for data Tx (i=%d)\n",
+                              i);
+                       goto wr_exit;
                }
        }
-
-       return 0;
+       /*
+        * poll ARDY bit for making sure that last byte really has been
+        * transferred on the bus.
+        */
+       do {
+               status = wait_for_event(adap);
+       } while (!(status & I2C_STAT_ARDY) && timeout--);
+       if (timeout <= 0)
+               printf("i2c_write: timed out writig last byte!\n");
+
+wr_exit:
+       flush_fifo(adap);
+       writew(0xFFFF, &i2c_base->stat);
+       return i2c_error;
 }
 
-static void wait_for_bb (void)
+/*
+ * Wait for the bus to be free by checking the Bus Busy (BB)
+ * bit to become clear
+ */
+static int wait_for_bb(struct i2c_adapter *adap)
 {
-       int timeout = 10;
+       struct i2c *i2c_base = omap24_get_base(adap);
+       int timeout = I2C_TIMEOUT;
        u16 stat;
 
-       outw(0xFFFF, I2C_STAT);  /* clear current interruts...*/
-       while ((stat = inw (I2C_STAT) & I2C_STAT_BB) && timeout--) {
-               outw (stat, I2C_STAT);
-               udelay (50000);
+       writew(0xFFFF, &i2c_base->stat);        /* clear current interrupts...*/
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+       while ((stat = readw(&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
+#else
+       /* Read RAW status */
+       while ((stat = readw(&i2c_base->irqstatus_raw) &
+               I2C_STAT_BB) && timeout--) {
+#endif
+               writew(stat, &i2c_base->stat);
+               udelay(adap->waitdelay);
        }
 
        if (timeout <= 0) {
-               printf ("timed out in wait_for_bb: I2C_STAT=%x\n",
-                       inw (I2C_STAT));
+               printf("Timed out in wait_for_bb: status=%04x\n",
+                      stat);
+               return 1;
        }
-       outw(0xFFFF, I2C_STAT);  /* clear delayed stuff*/
+       writew(0xFFFF, &i2c_base->stat);         /* clear delayed stuff*/
+       return 0;
 }
 
-static u16 wait_for_pin (void)
+/*
+ * Wait for the I2C controller to complete current action
+ * and update status
+ */
+static u16 wait_for_event(struct i2c_adapter *adap)
 {
+       struct i2c *i2c_base = omap24_get_base(adap);
        u16 status;
-       int timeout = 10;
+       int timeout = I2C_TIMEOUT;
 
        do {
-               udelay (1000);
-               status = inw (I2C_STAT);
-       } while (  !(status &
+               udelay(adap->waitdelay);
+#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
+               status = readw(&i2c_base->stat);
+#else
+               /* Read RAW status */
+               status = readw(&i2c_base->irqstatus_raw);
+#endif
+       } while (!(status &
                   (I2C_STAT_ROVR | I2C_STAT_XUDF | I2C_STAT_XRDY |
                    I2C_STAT_RRDY | I2C_STAT_ARDY | I2C_STAT_NACK |
                    I2C_STAT_AL)) && timeout--);
 
        if (timeout <= 0) {
-               printf ("timed out in wait_for_pin: I2C_STAT=%x\n",
-                       inw (I2C_STAT));
-                       outw(0xFFFF, I2C_STAT);
-}
+               printf("Timed out in wait_for_event: status=%04x\n",
+                      status);
+               /*
+                * If status is still 0 here, probably the bus pads have
+                * not been configured for I2C, and/or pull-ups are missing.
+                */
+               printf("Check if pads/pull-ups of bus %d are properly configured\n",
+                      adap->hwadapnr);
+               writew(0xFFFF, &i2c_base->stat);
+               status = 0;
+       }
+
        return status;
 }
 
-#endif /* CONFIG_DRIVER_OMAP24XX_I2C */
+static struct i2c *omap24_get_base(struct i2c_adapter *adap)
+{
+       switch (adap->hwadapnr) {
+       case 0:
+               return (struct i2c *)I2C_BASE1;
+               break;
+       case 1:
+               return (struct i2c *)I2C_BASE2;
+               break;
+#if (I2C_BUS_MAX > 2)
+       case 2:
+               return (struct i2c *)I2C_BASE3;
+               break;
+#if (I2C_BUS_MAX > 3)
+       case 3:
+               return (struct i2c *)I2C_BASE4;
+               break;
+#if (I2C_BUS_MAX > 4)
+       case 4:
+               return (struct i2c *)I2C_BASE5;
+               break;
+#endif
+#endif
+#endif
+       default:
+               printf("wrong hwadapnr: %d\n", adap->hwadapnr);
+               break;
+       }
+       return NULL;
+}
+
+#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED1)
+#define CONFIG_SYS_OMAP24_I2C_SPEED1 CONFIG_SYS_OMAP24_I2C_SPEED
+#endif
+#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE1)
+#define CONFIG_SYS_OMAP24_I2C_SLAVE1 CONFIG_SYS_OMAP24_I2C_SLAVE
+#endif
+
+U_BOOT_I2C_ADAP_COMPLETE(omap24_0, omap24_i2c_init, omap24_i2c_probe,
+                        omap24_i2c_read, omap24_i2c_write, omap24_i2c_setspeed,
+                        CONFIG_SYS_OMAP24_I2C_SPEED,
+                        CONFIG_SYS_OMAP24_I2C_SLAVE,
+                        0)
+U_BOOT_I2C_ADAP_COMPLETE(omap24_1, omap24_i2c_init, omap24_i2c_probe,
+                        omap24_i2c_read, omap24_i2c_write, omap24_i2c_setspeed,
+                        CONFIG_SYS_OMAP24_I2C_SPEED1,
+                        CONFIG_SYS_OMAP24_I2C_SLAVE1,
+                        1)
+#if (I2C_BUS_MAX > 2)
+#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED2)
+#define CONFIG_SYS_OMAP24_I2C_SPEED2 CONFIG_SYS_OMAP24_I2C_SPEED
+#endif
+#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE2)
+#define CONFIG_SYS_OMAP24_I2C_SLAVE2 CONFIG_SYS_OMAP24_I2C_SLAVE
+#endif
+
+U_BOOT_I2C_ADAP_COMPLETE(omap24_2, omap24_i2c_init, omap24_i2c_probe,
+                        omap24_i2c_read, omap24_i2c_write, NULL,
+                        CONFIG_SYS_OMAP24_I2C_SPEED2,
+                        CONFIG_SYS_OMAP24_I2C_SLAVE2,
+                        2)
+#if (I2C_BUS_MAX > 3)
+#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED3)
+#define CONFIG_SYS_OMAP24_I2C_SPEED3 CONFIG_SYS_OMAP24_I2C_SPEED
+#endif
+#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE3)
+#define CONFIG_SYS_OMAP24_I2C_SLAVE3 CONFIG_SYS_OMAP24_I2C_SLAVE
+#endif
+
+U_BOOT_I2C_ADAP_COMPLETE(omap24_3, omap24_i2c_init, omap24_i2c_probe,
+                        omap24_i2c_read, omap24_i2c_write, NULL,
+                        CONFIG_SYS_OMAP24_I2C_SPEED3,
+                        CONFIG_SYS_OMAP24_I2C_SLAVE3,
+                        3)
+#if (I2C_BUS_MAX > 4)
+#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED4)
+#define CONFIG_SYS_OMAP24_I2C_SPEED4 CONFIG_SYS_OMAP24_I2C_SPEED
+#endif
+#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE4)
+#define CONFIG_SYS_OMAP24_I2C_SLAVE4 CONFIG_SYS_OMAP24_I2C_SLAVE
+#endif
+
+U_BOOT_I2C_ADAP_COMPLETE(omap24_4, omap24_i2c_init, omap24_i2c_probe,
+                        omap24_i2c_read, omap24_i2c_write, NULL,
+                        CONFIG_SYS_OMAP24_I2C_SPEED4,
+                        CONFIG_SYS_OMAP24_I2C_SLAVE4,
+                        4)
+#endif
+#endif
+#endif