diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-omap.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 00fd02ec1b65..fdba13137daf 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -166,6 +166,8 @@ enum { #define SYSC_IDLEMODE_SMART 0x2 #define SYSC_CLOCKACTIVITY_FCLK 0x2 +/* Errata definitions */ +#define I2C_OMAP_ERRATA_I207 (1 << 0) struct omap_i2c_dev { struct device *dev; @@ -199,6 +201,7 @@ struct omap_i2c_dev { u16 bufstate; u16 syscstate; u16 westate; + u16 errata; }; const static u8 reg_map[] = { @@ -498,6 +501,11 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) /* Take the I2C module out of reset: */ omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); + dev->errata = 0; + + if (cpu_is_omap2430() || cpu_is_omap34xx()) + dev->errata |= I2C_OMAP_ERRATA_I207; + /* Enable interrupts */ dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | @@ -695,6 +703,34 @@ omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat) omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat); } +static inline void i2c_omap_errata_i207(struct omap_i2c_dev *dev, u16 stat) +{ + /* + * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8) + * Not applicable for OMAP4. + * Under certain rare conditions, RDR could be set again + * when the bus is busy, then ignore the interrupt and + * clear the interrupt. + */ + if (stat & OMAP_I2C_STAT_RDR) { + /* Step 1: If RDR is set, clear it */ + omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR); + + /* Step 2: */ + if (!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) + & OMAP_I2C_STAT_BB)) { + + /* Step 3: */ + if (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) + & OMAP_I2C_STAT_RDR) { + omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR); + dev_dbg(dev->dev, "RDR when bus is busy.\n"); + } + + } + } +} + /* rev1 devices are apparently only on some 15xx */ #ifdef CONFIG_ARCH_OMAP15XX @@ -834,6 +870,10 @@ complete: } if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) { u8 num_bytes = 1; + + if (dev->errata & I2C_OMAP_ERRATA_I207) + i2c_omap_errata_i207(dev, stat); + if (dev->fifo_size) { if (stat & OMAP_I2C_STAT_RRDY) num_bytes = dev->fifo_size; |