The values are already configurable from ACPI.
This patch makes the high count (HCNT) and low count (LCNT)
register values configurable through device tree.
Cc: xe-linux-exter...@cisco.com
Signed-off-by: Shikhar Dogra <shido...@cisco.com>
---
Documentation/devicetree/bindings/i2c/i2c-designware.txt | 16 ++++++++++++++++
drivers/i2c/busses/i2c-designware-platdrv.c | 12 ++++++++++++
2 files changed, 28 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
index fee26dc..2b9ddca 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
@@ -20,6 +20,18 @@ Optional properties :
- i2c-sda-falling-time-ns : should contain the SDA falling time in
nanoseconds.
This value which is by default 300ns is used to compute the tHIGH period.
+ - i2c-ss-hcnt : should contain the I2C controller standard speed HCNT value.
+ If this is not set we use the calculated and more conservative values.
+
+ - i2c-ss-lcnt : should contain the I2C controller standard speed LCNT value.
+ If this is not set we use the calculated and more conservative values.
+
+ - i2c-fs-hcnt : should contain the I2C controller fast speed HCNT value.
+ If this is not set we use the calculated and more conservative values.
+
+ - i2c-fs-lcnt : should contain the I2C controller fast speed LCNT value.
+ If this is not set we use the calculated and more conservative values.
+
Example :
i2c@f0000 {
@@ -42,4 +54,8 @@ Example :
i2c-sda-hold-time-ns = <300>;
i2c-sda-falling-time-ns = <300>;
i2c-scl-falling-time-ns = <300>;
+ i2c-ss-hcnt = /bits/ 16 <5000>;
+ i2c-ss-lcnt = /bits/ 16 <5000>;
+ i2c-fs-hcnt = /bits/ 16 <5000>;
+ i2c-fs-lcnt = /bits/ 16 <5000>;
};
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c
b/drivers/i2c/busses/i2c-designware-platdrv.c
index 6b00061c..25c3b0c 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -177,6 +177,18 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
of_property_read_u32(pdev->dev.of_node, "clock-frequency",
&clk_freq);
+ of_property_read_u16(pdev->dev.of_node,
+ "i2c-ss-hcnt", &dev->ss_hcnt);
+
+ of_property_read_u16(pdev->dev.of_node,
+ "i2c-ss-lcnt", &dev->ss_lcnt);
+
+ of_property_read_u16(pdev->dev.of_node,
+ "i2c-fs-hcnt", &dev->fs_hcnt);
+
+ of_property_read_u16(pdev->dev.of_node,
+ "i2c-fs-lcnt", &dev->fs_lcnt);
+
/* Only standard mode at 100kHz and fast mode at 400kHz
* are supported.
*/
--
2.7.4
