4 files changed, 43 insertions, 28 deletions
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index 48914dfc8ce8..d1c93acabfcf 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -94,6 +94,40 @@ void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
 	}
 }
 
+/**
+ * i2c_dw_set_reg_access() - Set register access flags
+ * @dev: device private data
+ *
+ * Autodetects needed register access mode and sets access flags accordingly.
+ * This must be called before doing any other register access.
+ */
+int i2c_dw_set_reg_access(struct dw_i2c_dev *dev)
+{
+	u32 reg;
+	int ret;
+
+	ret = i2c_dw_acquire_lock(dev);
+	if (ret)
+		return ret;
+
+	reg = dw_readl(dev, DW_IC_COMP_TYPE);
+	i2c_dw_release_lock(dev);
+
+	if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
+		/* Configure register endianess access */
+		dev->flags |= ACCESS_SWAP;
+	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
+		/* Configure register access mode 16bit */
+		dev->flags |= ACCESS_16BIT;
+	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
+		dev_err(dev->dev,
+			"Unknown Synopsys component type: 0x%08x\n", reg);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
 {
 	/*
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index d690e648bc01..5d54f70710ad 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -295,6 +295,7 @@ struct dw_i2c_dev {
 
 u32 dw_readl(struct dw_i2c_dev *dev, int offset);
 void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset);
+int i2c_dw_set_reg_access(struct dw_i2c_dev *dev);
 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset);
 u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
 unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev);
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 27436a937492..3a7c184f24c8 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -64,20 +64,6 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev)
 	if (ret)
 		return ret;
 
-	reg = dw_readl(dev, DW_IC_COMP_TYPE);
-	if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
-		/* Configure register endianess access */
-		dev->flags |= ACCESS_SWAP;
-	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
-		/* Configure register access mode 16bit */
-		dev->flags |= ACCESS_16BIT;
-	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
-		dev_err(dev->dev,
-			"Unknown Synopsys component type: 0x%08x\n", reg);
-		i2c_dw_release_lock(dev);
-		return -ENODEV;
-	}
-
 	comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
 
 	/* Disable the adapter */
@@ -681,6 +667,10 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
 	dev->disable = i2c_dw_disable;
 	dev->disable_int = i2c_dw_disable_int;
 
+	ret = i2c_dw_set_reg_access(dev);
+	if (ret)
+		return ret;
+
 	ret = dev->init(dev);
 	if (ret)
 		return ret;
diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index 2036a579b5df..a1f802001e1f 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -58,20 +58,6 @@ static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
 	if (ret)
 		return ret;
 
-	reg = dw_readl(dev, DW_IC_COMP_TYPE);
-	if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
-		/* Configure register endianness access. */
-		dev->flags |= ACCESS_SWAP;
-	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
-		/* Configure register access mode 16bit. */
-		dev->flags |= ACCESS_16BIT;
-	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
-		dev_err(dev->dev,
-			"Unknown Synopsys component type: 0x%08x\n", reg);
-		i2c_dw_release_lock(dev);
-		return -ENODEV;
-	}
-
 	/* Disable the adapter. */
 	__i2c_dw_disable(dev);
 
@@ -297,6 +283,10 @@ int i2c_dw_probe_slave(struct dw_i2c_dev *dev)
 	dev->disable = i2c_dw_disable;
 	dev->disable_int = i2c_dw_disable_int;
 
+	ret = i2c_dw_set_reg_access(dev);
+	if (ret)
+		return ret;
+
 	ret = dev->init(dev);
 	if (ret)
 		return ret;