2 files changed, 35 insertions, 18 deletions

diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index 8055cbd4cba1..5b6cb45da459 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -271,6 +271,17 @@ static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
 		 enable ? "en" : "dis");
 }
 
+static unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
+{
+	/*
+	 * Clock is not necessary if we got LCNT/HCNT values directly from
+	 * the platform code.
+	 */
+	if (WARN_ON_ONCE(!dev->get_clk_rate_khz))
+		return 0;
+	return dev->get_clk_rate_khz(dev);
+}
+
 /**
  * i2c_dw_init() - initialize the designware i2c master hardware
  * @dev: device private data
@@ -281,7 +292,6 @@ static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
  */
 int i2c_dw_init(struct dw_i2c_dev *dev)
 {
-	u32 input_clock_khz;
 	u32 hcnt, lcnt;
 	u32 reg;
 	u32 sda_falling_time, scl_falling_time;
@@ -295,8 +305,6 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 		}
 	}
 
-	input_clock_khz = dev->get_clk_rate_khz(dev);
-
 	reg = dw_readl(dev, DW_IC_COMP_TYPE);
 	if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
 		/* Configure register endianess access */
@@ -325,12 +333,12 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 		hcnt = dev->ss_hcnt;
 		lcnt = dev->ss_lcnt;
 	} else {
-		hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+		hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
 					4000,	/* tHD;STA = tHIGH = 4.0 us */
 					sda_falling_time,
 					0,	/* 0: DW default, 1: Ideal */
 					0);	/* No offset */
-		lcnt = i2c_dw_scl_lcnt(input_clock_khz,
+		lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
 					4700,	/* tLOW = 4.7 us */
 					scl_falling_time,
 					0);	/* No offset */
@@ -344,12 +352,12 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 		hcnt = dev->fs_hcnt;
 		lcnt = dev->fs_lcnt;
 	} else {
-		hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+		hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
 					600,	/* tHD;STA = tHIGH = 0.6 us */
 					sda_falling_time,
 					0,	/* 0: DW default, 1: Ideal */
 					0);	/* No offset */
-		lcnt = i2c_dw_scl_lcnt(input_clock_khz,
+		lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
 					1300,	/* tLOW = 1.3 us */
 					scl_falling_time,
 					0);	/* No offset */
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 8ffc36b8a6d3..965512c3b1cf 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -128,6 +128,18 @@ static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 }
 #endif
 
+static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
+{
+	if (IS_ERR(i_dev->clk))
+		return PTR_ERR(i_dev->clk);
+
+	if (prepare)
+		return clk_prepare_enable(i_dev->clk);
+
+	clk_disable_unprepare(i_dev->clk);
+	return 0;
+}
+
 static int dw_i2c_plat_probe(struct platform_device *pdev)
 {
 	struct dw_i2c_dev *dev;
@@ -205,16 +217,13 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 			DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
 
 	dev->clk = devm_clk_get(&pdev->dev, NULL);
-	dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
-	if (IS_ERR(dev->clk))
-		return PTR_ERR(dev->clk);
-	clk_prepare_enable(dev->clk);
+	if (!i2c_dw_plat_prepare_clk(dev, true)) {
+		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 
-	if (!dev->sda_hold_time && ht) {
-		u32 ic_clk = dev->get_clk_rate_khz(dev);
-
-		dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
-					     1000000);
+		if (!dev->sda_hold_time && ht)
+			dev->sda_hold_time = div_u64(
+				(u64)dev->get_clk_rate_khz(dev) * ht + 500000,
+				1000000);
 	}
 
 	if (!dev->tx_fifo_depth) {
@@ -297,7 +306,7 @@ static int dw_i2c_plat_suspend(struct device *dev)
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 
 	i2c_dw_disable(i_dev);
-	clk_disable_unprepare(i_dev->clk);
+	i2c_dw_plat_prepare_clk(i_dev, false);
 
 	return 0;
 }
@@ -307,7 +316,7 @@ static int dw_i2c_plat_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 
-	clk_prepare_enable(i_dev->clk);
+	i2c_dw_plat_prepare_clk(i_dev, true);
 
 	if (!i_dev->pm_runtime_disabled)
 		i2c_dw_init(i_dev);