diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-core.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-core.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index c41ca6354fc5..ad46616de29e 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -67,9 +67,12 @@ #define DW_IC_STATUS 0x70 #define DW_IC_TXFLR 0x74 #define DW_IC_RXFLR 0x78 +#define DW_IC_SDA_HOLD 0x7c #define DW_IC_TX_ABRT_SOURCE 0x80 #define DW_IC_ENABLE_STATUS 0x9c #define DW_IC_COMP_PARAM_1 0xf4 +#define DW_IC_COMP_VERSION 0xf8 +#define DW_IC_SDA_HOLD_MIN_VERS 0x3131312A #define DW_IC_COMP_TYPE 0xfc #define DW_IC_COMP_TYPE_VALUE 0x44570140 @@ -332,6 +335,16 @@ int i2c_dw_init(struct dw_i2c_dev *dev) dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT); dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); + /* Configure SDA Hold Time if required */ + if (dev->sda_hold_time) { + reg = dw_readl(dev, DW_IC_COMP_VERSION); + if (reg >= DW_IC_SDA_HOLD_MIN_VERS) + dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD); + else + dev_warn(dev->dev, + "Hardware too old to adjust SDA hold time."); + } + /* Configure Tx/Rx FIFO threshold levels */ dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL); dw_writel(dev, 0, DW_IC_RX_TL); @@ -580,14 +593,23 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) i2c_dw_xfer_init(dev); /* wait for tx to complete */ - ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ); + ret = wait_for_completion_timeout(&dev->cmd_complete, HZ); if (ret == 0) { dev_err(dev->dev, "controller timed out\n"); + /* i2c_dw_init implicitly disables the adapter */ i2c_dw_init(dev); ret = -ETIMEDOUT; goto done; - } else if (ret < 0) - goto done; + } + + /* + * We must disable the adapter before unlocking the &dev->lock mutex + * below. Otherwise the hardware might continue generating interrupts + * which in turn causes a race condition with the following transfer. + * Needs some more investigation if the additional interrupts are + * a hardware bug or this driver doesn't handle them correctly yet. + */ + __i2c_dw_enable(dev, false); if (dev->msg_err) { ret = dev->msg_err; @@ -596,8 +618,6 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) /* no error */ if (likely(!dev->cmd_err)) { - /* Disable the adapter */ - __i2c_dw_enable(dev, false); ret = num; goto done; } |