diff --git a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt
index dde6c22..925d6eb 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt
@@ -21,6 +21,14 @@ Required on RK3066, RK3188 :
 Optional properties :
 
  - clock-frequency : SCL frequency to use (in Hz). If omitted, 100kHz is used.
+ - i2c-scl-rising-time-ns : Number of nanoseconds the signal takes to rise
+	(t(r) in i2c spec). If not specified this is assumed to be the max the
+	spec allows(1000 ns for standard mode, 300 ns for fast mode) which
+	might cause slightly slower communication.
+ - i2c-scl-falling-time-ns : Number of nanoseconds the signal takes to fall
+	(t(f) in the i2c0 spec).  If not specified this is assumed to be the
+	max the spec allows (300 ns) which might cause slightly slower
+	communication.
 
 Example:
 
@@ -39,4 +47,7 @@ i2c0: i2c@2002d000 {
 
 	clock-names = "i2c";
 	clocks = <&cru PCLK_I2C0>;
+
+	i2c-scl-rising-time-ns = <800>;
+	i2c-scl-falling-time-ns = <100>;
 };
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 0ee5802..50c1678 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -102,6 +102,8 @@ struct rk3x_i2c {
 
 	/* Settings */
 	unsigned int scl_frequency;
+	unsigned int rise_ns;
+	unsigned int fall_ns;
 
 	/* Synchronization & notification */
 	spinlock_t lock;
@@ -435,6 +437,8 @@ out:
  *
  * @clk_rate: I2C input clock rate
  * @scl_rate: Desired SCL rate
+ * @rise_ns: How many ns it takes for signals to rise.
+ * @fall_ns: How many ns it takes for signals to fall.
  * @div_low: Divider output for low
  * @div_high: Divider output for high
  *
@@ -443,11 +447,14 @@ out:
  * too high, we silently use the highest possible rate.
  */
 static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
+			      unsigned long rise_ns, unsigned long fall_ns,
 			      unsigned long *div_low, unsigned long *div_high)
 {
+	unsigned long spec_min_low_ns, spec_min_high_ns;
+	unsigned long spec_max_data_hold_ns;
+	unsigned long spec_data_hold_buffer_ns;
+
 	unsigned long min_low_ns, min_high_ns;
-	unsigned long max_data_hold_ns;
-	unsigned long data_hold_buffer_ns;
 	unsigned long max_low_ns, min_total_ns;
 
 	unsigned long clk_rate_khz, scl_rate_khz;
@@ -470,28 +477,30 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
 
 	/*
 	 * min_low_ns:  The minimum number of ns we need to hold low
-	 *		to meet i2c spec
+	 *		to meet i2c spec, should include fall time.
 	 * min_high_ns: The minimum number of ns we need to hold high
-	 *		to meet i2c spec
+	 *		to meet i2c spec, should include rise time.
 	 * max_low_ns:  The maximum number of ns we can hold low
-	 *		to meet i2c spec
+	 *		to meet i2c spec.
 	 *
 	 * Note: max_low_ns should be (max data hold time * 2 - buffer)
 	 *	 This is because the i2c host on Rockchip holds the data line
 	 *	 for half the low time.
 	 */
 	if (scl_rate <= 100000) {
-		min_low_ns = 4700;
-		min_high_ns = 4000;
-		max_data_hold_ns = 3450;
-		data_hold_buffer_ns = 50;
+		spec_min_low_ns = 4700;
+		spec_min_high_ns = 4000;
+		spec_max_data_hold_ns = 3450;
+		spec_data_hold_buffer_ns = 50;
 	} else {
-		min_low_ns = 1300;
-		min_high_ns = 600;
-		max_data_hold_ns = 900;
-		data_hold_buffer_ns = 50;
+		spec_min_low_ns = 1300;
+		spec_min_high_ns = 600;
+		spec_max_data_hold_ns = 900;
+		spec_data_hold_buffer_ns = 50;
 	}
-	max_low_ns = max_data_hold_ns * 2 - data_hold_buffer_ns;
+	min_low_ns = spec_min_low_ns + fall_ns;
+	min_high_ns = spec_min_high_ns + rise_ns;
+	max_low_ns = spec_max_data_hold_ns * 2 - spec_data_hold_buffer_ns;
 	min_total_ns = min_low_ns + min_high_ns;
 
 	/* Adjust to avoid overflow */
@@ -588,8 +597,8 @@ static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
 	u64 t_low_ns, t_high_ns;
 	int ret;
 
-	ret = rk3x_i2c_calc_divs(clk_rate, i2c->scl_frequency, &div_low,
-				 &div_high);
+	ret = rk3x_i2c_calc_divs(clk_rate, i2c->scl_frequency, i2c->rise_ns,
+				 i2c->fall_ns, &div_low, &div_high);
 
 	WARN_ONCE(ret != 0, "Could not reach SCL freq %u", i2c->scl_frequency);
 
@@ -633,9 +642,9 @@ static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
 	switch (event) {
 	case PRE_RATE_CHANGE:
 		if (rk3x_i2c_calc_divs(ndata->new_rate, i2c->scl_frequency,
-				      &div_low, &div_high) != 0) {
+				       i2c->rise_ns, i2c->fall_ns, &div_low,
+				       &div_high) != 0)
 			return NOTIFY_STOP;
-		}
 
 		/* scale up */
 		if (ndata->new_rate > ndata->old_rate)
@@ -859,6 +868,18 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 		i2c->scl_frequency = DEFAULT_SCL_RATE;
 	}
 
+	/* Read rise and fall ns; if not there use the default max from spec */
+	if (of_property_read_u32(pdev->dev.of_node, "i2c-scl-rising-time-ns",
+				 &i2c->rise_ns)) {
+		if (i2c->scl_frequency <= 100000)
+			i2c->rise_ns = 1000;
+		else
+			i2c->rise_ns = 300;
+	}
+	if (of_property_read_u32(pdev->dev.of_node, "i2c-scl-falling-time-ns",
+				 &i2c->fall_ns))
+		i2c->fall_ns = 300;
+
 	strlcpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name));
 	i2c->adap.owner = THIS_MODULE;
 	i2c->adap.algo = &rk3x_i2c_algorithm;
