Merge branch 'lsk-3.10-armlt-i2c' into integration-lsk-3.10-juno-android

6 files changed, 128 insertions, 23 deletions

diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
index e42a2ee233e6..5199b0c8cf7a 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
@@ -10,6 +10,16 @@ Recommended properties :
 
  - clock-frequency : desired I2C bus clock frequency in Hz.
 
+Optional properties :
+ - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds.
+   This option is only supported in hardware blocks version 1.11a or newer.
+
+ - i2c-scl-falling-time : should contain the SCL falling time in nanoseconds.
+   This value which is by default 300ns is used to compute the tLOW period.
+
+ - i2c-sda-falling-time : should contain the SDA falling time in nanoseconds.
+   This value which is by default 300ns is used to compute the tHIGH period.
+
 Example :
 
 	i2c@f0000 {
@@ -20,3 +30,16 @@ Example :
 		interrupts = <11>;
 		clock-frequency = <400000>;
 	};
+
+	i2c@1120000 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "snps,designware-i2c";
+		reg = <0x1120000 0x1000>;
+		interrupt-parent = <&ictl>;
+		interrupts = <12 1>;
+		clock-frequency = <400000>;
+		i2c-sda-hold-time-ns = <300>;
+		i2c-sda-falling-time-ns = <300>;
+		i2c-scl-falling-time-ns = <300>;
+	};
diff --git a/arch/arc/boot/dts/abilis_tb100_dvk.dts b/arch/arc/boot/dts/abilis_tb100_dvk.dts
index 0fa0d4abe795..ebc313a9f5b2 100644
--- a/arch/arc/boot/dts/abilis_tb100_dvk.dts
+++ b/arch/arc/boot/dts/abilis_tb100_dvk.dts
@@ -45,19 +45,19 @@
 		};
 
 		i2c0: i2c@FF120000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 		i2c1: i2c@FF121000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 		i2c2: i2c@FF122000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 		i2c3: i2c@FF123000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 		i2c4: i2c@FF124000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 
 		leds {
diff --git a/arch/arc/boot/dts/abilis_tb101_dvk.dts b/arch/arc/boot/dts/abilis_tb101_dvk.dts
index a4d80ce283ae..b204657993aa 100644
--- a/arch/arc/boot/dts/abilis_tb101_dvk.dts
+++ b/arch/arc/boot/dts/abilis_tb101_dvk.dts
@@ -45,19 +45,19 @@
 		};
 
 		i2c0: i2c@FF120000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 		i2c1: i2c@FF121000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 		i2c2: i2c@FF122000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 		i2c3: i2c@FF123000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 		i2c4: i2c@FF124000 {
-			sda-hold-time = <432>;
+			i2c-sda-hold-time-ns = <432>;
 		};
 
 		leds {
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c
index f24a7385260a..6a661052f7e1 100644
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -67,9 +67,12 @@
 #define DW_IC_STATUS		0x70
 #define DW_IC_TXFLR		0x74
 #define DW_IC_RXFLR		0x78
+#define DW_IC_SDA_HOLD		0x7c
 #define DW_IC_TX_ABRT_SOURCE	0x80
 #define DW_IC_ENABLE_STATUS	0x9c
 #define DW_IC_COMP_PARAM_1	0xf4
+#define DW_IC_COMP_VERSION	0xf8
+#define DW_IC_SDA_HOLD_MIN_VERS	0x3131312A
 #define DW_IC_COMP_TYPE		0xfc
 #define DW_IC_COMP_TYPE_VALUE	0x44570140
 
@@ -214,7 +217,7 @@ i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
 		 *
 		 * If your hardware is free from tHD;STA issue, try this one.
 		 */
-		return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset;
+		return (ic_clk * tSYMBOL + 500000) / 1000000 - 8 + offset;
 	else
 		/*
 		 * Conditional expression:
@@ -230,7 +233,8 @@ i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
 		 * The reason why we need to take into account "tf" here,
 		 * is the same as described in i2c_dw_scl_lcnt().
 		 */
-		return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset;
+		return (ic_clk * (tSYMBOL + tf) + 500000) / 1000000
+			- 3 + offset;
 }
 
 static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
@@ -246,7 +250,7 @@ static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
 	 * account the fall time of SCL signal (tf).  Default tf value
 	 * should be 0.3 us, for safety.
 	 */
-	return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset;
+	return ((ic_clk * (tLOW + tf) + 500000) / 1000000) - 1 + offset;
 }
 
 static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
@@ -283,6 +287,7 @@ 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;
 
 	input_clock_khz = dev->get_clk_rate_khz(dev);
 
@@ -304,36 +309,60 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 
 	/* set standard and fast speed deviders for high/low periods */
 
+	sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
+	scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
+
 	/* Standard-mode */
 	hcnt = i2c_dw_scl_hcnt(input_clock_khz,
-				40,	/* tHD;STA = tHIGH = 4.0 us */
-				3,	/* tf = 0.3 us */
+				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,
-				47,	/* tLOW = 4.7 us */
-				3,	/* tf = 0.3 us */
+				4700,	/* tLOW = 4.7 us */
+				scl_falling_time,
 				0);	/* No offset */
+
+	/* Allow platforms to specify the ideal HCNT and LCNT values */
+	if (dev->ss_hcnt && dev->ss_lcnt) {
+		hcnt = dev->ss_hcnt;
+		lcnt = dev->ss_lcnt;
+	}
 	dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
 	dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
 	dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
 
 	/* Fast-mode */
 	hcnt = i2c_dw_scl_hcnt(input_clock_khz,
-				6,	/* tHD;STA = tHIGH = 0.6 us */
-				3,	/* tf = 0.3 us */
+				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,
-				13,	/* tLOW = 1.3 us */
-				3,	/* tf = 0.3 us */
+				1300,	/* tLOW = 1.3 us */
+				scl_falling_time,
 				0);	/* No offset */
+
+	if (dev->fs_hcnt && dev->fs_lcnt) {
+		hcnt = dev->fs_hcnt;
+		lcnt = dev->fs_lcnt;
+	}
 	dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
 	dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
 	dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
 
+	/* Configure SDA Hold Time if required */
+	if (dev->sda_hold_time) {
+		reg = dw_readl(dev, DW_IC_COMP_VERSION);
+		if (reg >= DW_IC_SDA_HOLD_MIN_VERS)
+			dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
+		else
+			dev_warn(dev->dev,
+				"Hardware too old to adjust SDA hold time.");
+	}
+
 	/* Configure Tx/Rx FIFO threshold levels */
-	dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL);
+	dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
 	dw_writel(dev, 0, DW_IC_RX_TL);
 
 	/* configure the i2c master */
@@ -383,6 +412,9 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
 	/* enforce disabled interrupts (due to HW issues) */
 	i2c_dw_disable_int(dev);
 
+	/* enforce disabled interrupts (due to HW issues) */
+	i2c_dw_disable_int(dev);
+
 	/* Enable the adapter */
 	__i2c_dw_enable(dev, true);
 
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index e761ad18dd61..d66b6cbc9edc 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -61,6 +61,14 @@
  * @tx_fifo_depth: depth of the hardware tx fifo
  * @rx_fifo_depth: depth of the hardware rx fifo
  * @rx_outstanding: current master-rx elements in tx fifo
+ * @ss_hcnt: standard speed HCNT value
+ * @ss_lcnt: standard speed LCNT value
+ * @fs_hcnt: fast speed HCNT value
+ * @fs_lcnt: fast speed LCNT value
+ *
+ * HCNT and LCNT parameters can be used if the platform knows more accurate
+ * values than the one computed based only on the input clock frequency.
+ * Leave them to be %0 if not used.
  */
 struct dw_i2c_dev {
 	struct device		*dev;
@@ -90,6 +98,13 @@ struct dw_i2c_dev {
 	unsigned int		tx_fifo_depth;
 	unsigned int		rx_fifo_depth;
 	int			rx_outstanding;
+	u32			sda_hold_time;
+	u32			sda_falling_time;
+	u32			scl_falling_time;
+	u16			ss_hcnt;
+	u16			ss_lcnt;
+	u16			fs_hcnt;
+	u16			fs_lcnt;
 };
 
 #define ACCESS_SWAP		0x00000001
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 35b70a1edf57..2da574a9f03f 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -34,6 +34,7 @@
 #include <linux/sched.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
+#include <linux/of.h>
 #include <linux/of_i2c.h>
 #include <linux/platform_device.h>
 #include <linux/pm.h>
@@ -86,6 +87,7 @@ static int dw_i2c_probe(struct platform_device *pdev)
 	struct i2c_adapter *adap;
 	struct resource *mem;
 	int irq, r;
+	u32 bus_rate = DW_IC_CON_SPEED_STD;
 
 	/* NOTE: driver uses the static register mapping */
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -121,6 +123,39 @@ static int dw_i2c_probe(struct platform_device *pdev)
 		return PTR_ERR(dev->clk);
 	clk_prepare_enable(dev->clk);
 
+	if (pdev->dev.of_node) {
+		u32 ht = 0;
+		u32 ic_clk = dev->get_clk_rate_khz(dev);
+
+		of_property_read_u32(pdev->dev.of_node,
+					"i2c-sda-hold-time-ns", &ht);
+		dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
+					     1000000);
+
+		of_property_read_u32(pdev->dev.of_node,
+				     "i2c-sda-falling-time-ns",
+				     &dev->sda_falling_time);
+		of_property_read_u32(pdev->dev.of_node,
+				     "i2c-scl-falling-time-ns",
+				     &dev->scl_falling_time);
+
+		r = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+						&bus_rate);
+		if (r)
+			bus_rate = 400000; /* default clock rate */
+		switch (bus_rate) {
+		case 400000:
+			bus_rate = DW_IC_CON_SPEED_FAST;
+			break;
+		case 100000:
+			bus_rate = DW_IC_CON_SPEED_STD;
+			break;
+		default:
+			dev_err(&pdev->dev, "Invalid bus speed (not 100kHz or 400kHz)\n");
+			return -EINVAL;
+		}
+	}
+
 	dev->functionality =
 		I2C_FUNC_I2C |
 		I2C_FUNC_10BIT_ADDR |
@@ -129,7 +164,7 @@ static int dw_i2c_probe(struct platform_device *pdev)
 		I2C_FUNC_SMBUS_WORD_DATA |
 		I2C_FUNC_SMBUS_I2C_BLOCK;
 	dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
-		DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
+		DW_IC_CON_RESTART_EN | bus_rate;
 
 	/* Try first if we can configure the device from ACPI */
 	r = dw_i2c_acpi_configure(pdev);