*
* 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>
+#include <i2c.h>
#include <asm/arch/i2c.h>
#include <asm/io.h>
#define I2C_TIMEOUT 1000
-static void wait_for_bb (void);
-static u16 wait_for_pin (void);
-static void flush_fifo(void);
-
-static struct i2c *i2c_base = (struct i2c *)I2C_DEFAULT_BASE;
-
-static unsigned int bus_initialized[I2C_BUS_MAX];
-static unsigned int current_bus;
+/* Absolutely safe for status update at 100 kHz I2C: */
+#define I2C_WAIT 200
-void i2c_init (int speed, int slaveadd)
+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)
{
- int psc, fsscll, fssclh;
- int hsscll = 0, hssclh = 0;
- u32 scll, sclh;
- int timeout = I2C_TIMEOUT;
+ 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);
- /* Only handle standard, fast and high speeds */
- if ((speed != OMAP_I2C_STANDARD) &&
- (speed != OMAP_I2C_FAST_MODE) &&
- (speed != OMAP_I2C_HIGH_SPEED)) {
- printf("Error : I2C unsupported speed %d\n", speed);
- return;
- }
+ fsscll = sampleclk / speed;
+ fssclh = fsscll;
+ fsscll -= I2C_FASTSPEED_SCLL_TRIM;
+ fssclh -= I2C_FASTSPEED_SCLH_TRIM;
- psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK;
- psc -= 1;
- if (psc < I2C_PSC_MIN) {
- printf("Error : I2C unsupported prescalar %d\n", psc);
- return;
+ 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++;
}
+ return -1;
+}
+static uint omap24_i2c_setspeed(struct i2c_adapter *adap, uint speed)
+{
+ 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) {
+ 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;
+ }
/* For first phase of HS mode */
- fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK /
- (2 * OMAP_I2C_FAST_MODE);
+ fsscll = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
+
+ fssclh = fsscll;
fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM;
fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
if (((fsscll < 0) || (fssclh < 0)) ||
((fsscll > 255) || (fssclh > 255))) {
- printf("Error : I2C initializing first phase clock\n");
- return;
+ puts("Error : I2C initializing first phase clock\n");
+ return -1;
}
/* For second phase of HS mode */
hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
if (((fsscll < 0) || (fssclh < 0)) ||
((fsscll > 255) || (fssclh > 255))) {
- printf("Error : I2C initializing second phase clock\n");
- return;
+ puts("Error : I2C initializing second phase clock\n");
+ return -1;
}
scll = (unsigned int)hsscll << 8 | (unsigned int)fsscll;
} else {
/* Standard and fast speed */
- fsscll = fssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
-
- fsscll -= I2C_FASTSPEED_SCLL_TRIM;
- fssclh -= I2C_FASTSPEED_SCLH_TRIM;
- if (((fsscll < 0) || (fssclh < 0)) ||
- ((fsscll > 255) || (fssclh > 255))) {
- printf("Error : I2C initializing clock\n");
- return;
+ psc = omap24_i2c_findpsc(&scll, &sclh, speed);
+ if (0 > psc) {
+ puts("Error : I2C initializing clock\n");
+ return -1;
}
-
- scll = (unsigned int)fsscll;
- sclh = (unsigned int)fssclh;
- }
-
- if (readw (&i2c_base->con) & I2C_CON_EN) {
- writew (0, &i2c_base->con);
- udelay (50000);
- }
-
- writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
- udelay(1000);
-
- writew(I2C_CON_EN, &i2c_base->con);
- while (!(readw(&i2c_base->syss) & I2C_SYSS_RDONE) && timeout--) {
- if (timeout <= 0) {
- printf("ERROR: Timeout in soft-reset\n");
- return;
- }
- udelay(1000);
}
+ 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 */
- /* own address */
- writew (slaveadd, &i2c_base->oa);
- writew (I2C_CON_EN, &i2c_base->con);
-
- /* have to enable intrrupts or OMAP i2c module doesn't work */
- writew (I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
- I2C_IE_NACK_IE | I2C_IE_AL_IE, &i2c_base->ie);
- udelay (1000);
- flush_fifo();
- writew (0xFFFF, &i2c_base->stat);
- writew (0, &i2c_base->cnt);
-
- if (gd->flags & GD_FLG_RELOC)
- bus_initialized[current_bus] = 1;
+ return 0;
}
-static int i2c_read_byte (u8 devaddr, u8 regoffset, u8 * value)
+static void omap24_i2c_deblock(struct i2c_adapter *adap)
{
- int i2c_error = 0;
- u16 status;
-
- /* wait until bus not busy */
- wait_for_bb ();
-
- /* one byte only */
- writew (1, &i2c_base->cnt);
- /* set slave address */
- writew (devaddr, &i2c_base->sa);
- /* no stop bit needed here */
- writew (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX, &i2c_base->con);
-
- /* send register offset */
- while (1) {
- status = wait_for_pin();
- if (status == 0 || status & I2C_STAT_NACK) {
- i2c_error = 1;
- goto read_exit;
- }
- if (status & I2C_STAT_XRDY) {
- /* Important: have to use byte access */
- writeb(regoffset, &i2c_base->data);
- writew(I2C_STAT_XRDY, &i2c_base->stat);
- }
- if (status & I2C_STAT_ARDY) {
- writew(I2C_STAT_ARDY, &i2c_base->stat);
- break;
- }
+ 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);
}
- /* set slave address */
- writew(devaddr, &i2c_base->sa);
- /* read one byte from slave */
- writew(1, &i2c_base->cnt);
- /* need stop bit here */
- writew(I2C_CON_EN | I2C_CON_MST |
- I2C_CON_STT | I2C_CON_STP,
- &i2c_base->con);
+ /* 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);
- /* receive data */
- while (1) {
- status = wait_for_pin();
- if (status == 0 || status & I2C_STAT_NACK) {
- i2c_error = 1;
- goto read_exit;
- }
- if (status & I2C_STAT_RRDY) {
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
- defined(CONFIG_OMAP44XX)
- *value = readb(&i2c_base->data);
-#else
- *value = readw(&i2c_base->data);
-#endif
- writew(I2C_STAT_RRDY, &i2c_base->stat);
- }
- if (status & I2C_STAT_ARDY) {
- writew(I2C_STAT_ARDY, &i2c_base->stat);
- break;
- }
- }
-
-read_exit:
- flush_fifo();
- writew (0xFFFF, &i2c_base->stat);
- writew (0, &i2c_base->cnt);
- return i2c_error;
+ /* 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;
+ struct i2c *i2c_base = omap24_get_base(adap);
+ int timeout = I2C_TIMEOUT;
+ int deblock = 1;
- /* wait until bus not busy */
- wait_for_bb ();
+retry:
+ if (readw(&i2c_base->con) & I2C_CON_EN) {
+ writew(0, &i2c_base->con);
+ udelay(50000);
+ }
- /* two bytes */
- writew (2, &i2c_base->cnt);
- /* set slave address */
- writew (devaddr, &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);
+ writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
+ udelay(1000);
- while (1) {
- status = wait_for_pin();
- if (status == 0 || status & I2C_STAT_NACK) {
- i2c_error = 1;
- goto write_exit;
+ 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;
}
- if (status & I2C_STAT_XRDY) {
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
- defined(CONFIG_OMAP44XX)
- /* send register offset */
- writeb(regoffset, &i2c_base->data);
- writew(I2C_STAT_XRDY, &i2c_base->stat);
+ udelay(1000);
+ }
- while (1) {
- status = wait_for_pin();
- if (status == 0 || status & I2C_STAT_NACK) {
- i2c_error = 1;
- goto write_exit;
- }
- if (status & I2C_STAT_XRDY) {
- /* send data */
- writeb(value, &i2c_base->data);
- writew(I2C_STAT_XRDY, &i2c_base->stat);
- }
- if (status & I2C_STAT_ARDY) {
- writew(I2C_STAT_ARDY, &i2c_base->stat);
- break;
- }
- }
- break;
-#else
- /* send out two bytes */
- writew((value << 8) + regoffset, &i2c_base->data);
- writew(I2C_STAT_XRDY, &i2c_base->stat);
-#endif
- }
- if (status & I2C_STAT_ARDY) {
- writew(I2C_STAT_ARDY, &i2c_base->stat);
- break;
- }
+ if (0 != omap24_i2c_setspeed(adap, speed)) {
+ printf("ERROR: failed to setup I2C bus-speed!\n");
+ return;
}
- wait_for_bb();
+ /* own address */
+ writew(slaveadd, &i2c_base->oa);
- status = readw(&i2c_base->stat);
- if (status & I2C_STAT_NACK)
- i2c_error = 1;
+#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);
-write_exit:
- flush_fifo();
- writew (0xFFFF, &i2c_base->stat);
- writew (0, &i2c_base->cnt);
- return i2c_error;
+ /* 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){
+ while (1) {
stat = readw(&i2c_base->stat);
- if(stat == I2C_STAT_RRDY){
-#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \
- defined(CONFIG_OMAP44XX)
+ if (stat == I2C_STAT_RRDY) {
readb(&i2c_base->data);
-#else
- readw(&i2c_base->data);
-#endif
- writew(I2C_STAT_RRDY,&i2c_base->stat);
+ 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 == readw (&i2c_base->oa)) {
+ if (chip == readw(&i2c_base->oa))
return res;
- }
- /* wait until bus not busy */
- wait_for_bb ();
+ /* Wait until bus is free */
+ if (wait_for_bb(adap))
+ return res;
- /* try to write one byte */
- writew (1, &i2c_base->cnt);
- /* set slave address */
- writew (chip, &i2c_base->sa);
- /* stop bit needed here */
+ /* 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_pin();
+ status = wait_for_event(adap);
- /* check for ACK (!NAK) */
- if (!(status & I2C_STAT_NACK))
- res = 0;
+ 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);
- /* abort transfer (force idle state) */
- writew(0, &i2c_base->con);
+ goto pr_exit;
+ }
- flush_fifo();
- writew (0, &i2c_base->cnt); /* don't allow any more data in...we don't want it.*/
+ /* 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 */
+ }
+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 (CONFIG_SYS_I2C_SPEED, CONFIG_SYS_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);
- return 0;
+ /* 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;
+ }
+ }
+
+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 < 0) {
+ puts("I2C write: addr len < 0\n");
+ return 1;
+ }
- if (alen > 1) {
- printf ("I2C read: addr len %d not supported\n", alen);
+ if (len < 0) {
+ puts("I2C write: data len < 0\n");
return 1;
}
- if (addr + len > 256) {
- printf ("I2C read: address out of range\n");
+ 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 (CONFIG_SYS_I2C_SPEED, CONFIG_SYS_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;
}
}
+ /*
+ * 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");
- return 0;
+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)
{
+ struct i2c *i2c_base = omap24_get_base(adap);
int timeout = I2C_TIMEOUT;
u16 stat;
- writew(0xFFFF, &i2c_base->stat); /* clear current interruts...*/
- while ((stat = readw (&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
- writew (stat, &i2c_base->stat);
- udelay(1000);
+ 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",
- readw (&i2c_base->stat));
+ printf("Timed out in wait_for_bb: status=%04x\n",
+ stat);
+ return 1;
}
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 = I2C_TIMEOUT;
do {
- udelay (1000);
- status = readw (&i2c_base->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",
- readw (&i2c_base->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;
}
-int i2c_set_bus_num(unsigned int bus)
+static struct i2c *omap24_get_base(struct i2c_adapter *adap)
{
- if ((bus < 0) || (bus >= I2C_BUS_MAX)) {
- printf("Bad bus: %d\n", bus);
- return -1;
+ 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 I2C_BUS_MAX==3
- if (bus == 2)
- i2c_base = (struct i2c *)I2C_BASE3;
- else
+#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
- if (bus == 1)
- i2c_base = (struct i2c *)I2C_BASE2;
- else
- i2c_base = (struct i2c *)I2C_BASE1;
- current_bus = bus;
+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
- if(!bus_initialized[current_bus])
- i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
+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
- return 0;
-}
+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
-int i2c_get_bus_num(void)
-{
- return (int) current_bus;
-}
+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