diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/omap24xx_i2c.c | 42 |
1 files changed, 31 insertions, 11 deletions
diff --git a/drivers/i2c/omap24xx_i2c.c b/drivers/i2c/omap24xx_i2c.c index a7ffd95d5d..3a50417b59 100644 --- a/drivers/i2c/omap24xx_i2c.c +++ b/drivers/i2c/omap24xx_i2c.c @@ -255,23 +255,43 @@ int i2c_probe(uchar chip) /* wait until bus not busy */ wait_for_bb(); - /* try to write one byte */ + /* try to read one byte */ writew(1, &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); - - status = wait_for_pin(); + writew (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP, &i2c_base->con); - /* check for ACK (!NAK) */ - if (!(status & I2C_STAT_NACK)) - res = 0; - - /* abort transfer (force idle state) */ - writew(0, &i2c_base->con); + while (1) { + status = wait_for_pin(); + if (status == 0 || status & I2C_STAT_AL) { + res = 1; + goto probe_exit; + } + if (status & I2C_STAT_NACK) { + res = 1; + writew(0xff, &i2c_base->stat); + writew (readw (&i2c_base->con) | I2C_CON_STP, &i2c_base->con); + wait_for_bb (); + break; + } + if (status & I2C_STAT_ARDY) { + writew(I2C_STAT_ARDY, &i2c_base->stat); + break; + } + if (status & I2C_STAT_RRDY) { + res = 0; +#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX) || \ + defined(CONFIG_OMAP44XX) + readb(&i2c_base->data); +#else + readw(&i2c_base->data); +#endif + writew(I2C_STAT_RRDY, &i2c_base->stat); + } + } +probe_exit: flush_fifo(); /* don't allow any more data in... we don't want it. */ writew(0, &i2c_base->cnt); |