diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index 6c8b38fd6e64..e4b1c4c71b62 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -145,7 +145,8 @@ struct aspeed_i2c_bus {
 	spinlock_t			lock;
 	struct completion		cmd_complete;
 	u32				(*get_clk_reg_val)(struct device *dev,
-							   u32 divisor);
+							   u32 divisor,
+							   u32 base_clk_div);
 	unsigned long			parent_clk_frequency;
 	u32				bus_frequency;
 	/* Transaction state. */
@@ -778,9 +779,10 @@ static const struct i2c_algorithm aspeed_i2c_algo = {
 
 static u32 aspeed_i2c_get_clk_reg_val(struct device *dev,
 				      u32 clk_high_low_mask,
-				      u32 divisor)
+				      u32 divisor,
+				      u32 base_clk_divisor)
 {
-	u32 base_clk_divisor, clk_high_low_max, clk_high, clk_low, tmp;
+	u32 clk_high_low_max, clk_high, clk_low, tmp;
 
 	/*
 	 * SCL_high and SCL_low represent a value 1 greater than what is stored
@@ -809,10 +811,12 @@ static u32 aspeed_i2c_get_clk_reg_val(struct device *dev,
 	 *		((1 << base_clk_divisor) * (clk_high + 1 + clk_low + 1))
 	 * The documentation recommends clk_high >= clk_high_max / 2 and
 	 * clk_low >= clk_low_max / 2 - 1 when possible; this last constraint
-	 * gives us the following solution:
+	 * gives us the following solution (unless base_clk_divisor is manually
+	 * configured in device tree):
 	 */
-	base_clk_divisor = divisor > clk_high_low_max ?
-			ilog2((divisor - 1) / clk_high_low_max) + 1 : 0;
+	if (base_clk_divisor > ASPEED_I2CD_TIME_BASE_DIVISOR_MASK)
+		base_clk_divisor = divisor > clk_high_low_max ?
+				ilog2((divisor - 1) / clk_high_low_max) + 1 : 0;
 
 	if (base_clk_divisor > ASPEED_I2CD_TIME_BASE_DIVISOR_MASK) {
 		base_clk_divisor = ASPEED_I2CD_TIME_BASE_DIVISOR_MASK;
@@ -843,35 +847,49 @@ static u32 aspeed_i2c_get_clk_reg_val(struct device *dev,
 			   & ASPEED_I2CD_TIME_BASE_DIVISOR_MASK);
 }
 
-static u32 aspeed_i2c_24xx_get_clk_reg_val(struct device *dev, u32 divisor)
+static u32 aspeed_i2c_24xx_get_clk_reg_val(struct device *dev,
+					   u32 divisor,
+					   u32 base_clk_divisor)
 {
 	/*
 	 * clk_high and clk_low are each 3 bits wide, so each can hold a max
 	 * value of 8 giving a clk_high_low_max of 16.
 	 */
-	return aspeed_i2c_get_clk_reg_val(dev, GENMASK(2, 0), divisor);
+	return aspeed_i2c_get_clk_reg_val(dev, GENMASK(2, 0), divisor,
+					  base_clk_divisor);
 }
 
-static u32 aspeed_i2c_25xx_get_clk_reg_val(struct device *dev, u32 divisor)
+static u32 aspeed_i2c_25xx_get_clk_reg_val(struct device *dev,
+					   u32 divisor,
+					   u32 base_clk_divisor)
 {
 	/*
 	 * clk_high and clk_low are each 4 bits wide, so each can hold a max
 	 * value of 16 giving a clk_high_low_max of 32.
 	 */
-	return aspeed_i2c_get_clk_reg_val(dev, GENMASK(3, 0), divisor);
+	return aspeed_i2c_get_clk_reg_val(dev, GENMASK(3, 0), divisor,
+					  base_clk_divisor);
 }
 
 /* precondition: bus.lock has been acquired. */
-static int aspeed_i2c_init_clk(struct aspeed_i2c_bus *bus)
+static int aspeed_i2c_init_clk(struct aspeed_i2c_bus *bus,
+			       struct platform_device *pdev)
 {
-	u32 divisor, clk_reg_val;
+	int ret;
+	u32 divisor, clk_reg_val, base_clk_divisor;
+
+	ret = of_property_read_u32(pdev->dev.of_node, "base-clock-divisor",
+				   &base_clk_divisor);
+	if (ret < 0)
+		base_clk_divisor = (u32)-1;
 
 	divisor = DIV_ROUND_UP(bus->parent_clk_frequency, bus->bus_frequency);
 	clk_reg_val = readl(bus->base + ASPEED_I2C_AC_TIMING_REG1);
 	clk_reg_val &= (ASPEED_I2CD_TIME_TBUF_MASK |
 			ASPEED_I2CD_TIME_THDSTA_MASK |
 			ASPEED_I2CD_TIME_TACST_MASK);
-	clk_reg_val |= bus->get_clk_reg_val(bus->dev, divisor);
+	clk_reg_val |= bus->get_clk_reg_val(bus->dev, divisor,
+					    base_clk_divisor);
 	writel(clk_reg_val, bus->base + ASPEED_I2C_AC_TIMING_REG1);
 	writel(ASPEED_NO_TIMEOUT_CTRL, bus->base + ASPEED_I2C_AC_TIMING_REG2);
 
@@ -888,7 +906,7 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus *bus,
 	/* Disable everything. */
 	writel(0, bus->base + ASPEED_I2C_FUN_CTRL_REG);
 
-	ret = aspeed_i2c_init_clk(bus);
+	ret = aspeed_i2c_init_clk(bus, pdev);
 	if (ret < 0)
 		return ret;
 
@@ -989,7 +1007,7 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
 	if (!match)
 		bus->get_clk_reg_val = aspeed_i2c_24xx_get_clk_reg_val;
 	else
-		bus->get_clk_reg_val = (u32 (*)(struct device *, u32))
+		bus->get_clk_reg_val = (u32 (*)(struct device *, u32, u32))
 				match->data;
 
 	/* Initialize the I2C adapter */
