diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-core.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-core.c | 39 |
1 files changed, 31 insertions, 8 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 94fd81875409..21fbb340ad66 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -68,6 +68,7 @@ #define DW_IC_TXFLR 0x74 #define DW_IC_RXFLR 0x78 #define DW_IC_TX_ABRT_SOURCE 0x80 +#define DW_IC_ENABLE_STATUS 0x9c #define DW_IC_COMP_PARAM_1 0xf4 #define DW_IC_COMP_TYPE 0xfc #define DW_IC_COMP_TYPE_VALUE 0x44570140 @@ -248,6 +249,27 @@ static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset) return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset; } +static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable) +{ + int timeout = 100; + + do { + dw_writel(dev, enable, DW_IC_ENABLE); + if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable) + return; + + /* + * Wait 10 times the signaling period of the highest I2C + * transfer supported by the driver (for 400KHz this is + * 25us) as described in the DesignWare I2C databook. + */ + usleep_range(25, 250); + } while (timeout--); + + dev_warn(dev->dev, "timeout in %sabling adapter\n", + enable ? "en" : "dis"); +} + /** * i2c_dw_init() - initialize the designware i2c master hardware * @dev: device private data @@ -278,7 +300,7 @@ int i2c_dw_init(struct dw_i2c_dev *dev) } /* Disable the adapter */ - dw_writel(dev, 0, DW_IC_ENABLE); + __i2c_dw_enable(dev, false); /* set standard and fast speed deviders for high/low periods */ @@ -333,7 +355,7 @@ static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev) return -ETIMEDOUT; } timeout--; - mdelay(1); + usleep_range(1000, 1100); } return 0; @@ -345,7 +367,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) u32 ic_con; /* Disable the adapter */ - dw_writel(dev, 0, DW_IC_ENABLE); + __i2c_dw_enable(dev, false); /* set the slave (target) address */ dw_writel(dev, msgs[dev->msg_write_idx].addr, DW_IC_TAR); @@ -359,7 +381,7 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) dw_writel(dev, ic_con, DW_IC_CON); /* Enable the adapter */ - dw_writel(dev, 1, DW_IC_ENABLE); + __i2c_dw_enable(dev, true); /* Enable interrupts */ dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK); @@ -565,7 +587,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) /* no error */ if (likely(!dev->cmd_err)) { /* Disable the adapter */ - dw_writel(dev, 0, DW_IC_ENABLE); + __i2c_dw_enable(dev, false); ret = num; goto done; } @@ -578,7 +600,8 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) ret = -EIO; done: - pm_runtime_put(dev->dev); + pm_runtime_mark_last_busy(dev->dev); + pm_runtime_put_autosuspend(dev->dev); mutex_unlock(&dev->lock); return ret; @@ -700,7 +723,7 @@ EXPORT_SYMBOL_GPL(i2c_dw_isr); void i2c_dw_enable(struct dw_i2c_dev *dev) { /* Enable the adapter */ - dw_writel(dev, 1, DW_IC_ENABLE); + __i2c_dw_enable(dev, true); } EXPORT_SYMBOL_GPL(i2c_dw_enable); @@ -713,7 +736,7 @@ EXPORT_SYMBOL_GPL(i2c_dw_is_enabled); void i2c_dw_disable(struct dw_i2c_dev *dev) { /* Disable controller */ - dw_writel(dev, 0, DW_IC_ENABLE); + __i2c_dw_enable(dev, false); /* Disable all interupts */ dw_writel(dev, 0, DW_IC_INTR_MASK); |