Hi
On 10/25/2017 09:50 PM, Shikhar Dogra wrote:
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-external@xxxxxxxxx
Signed-off-by: Shikhar Dogra <shidogra@xxxxxxxxx>
---
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.
+
Worth to add also properties for high-speed while at it.
Out of curiosity, are calculated values by using
"i2c-sda-falling-time-ns" and "i2c-scl-falling-time-ns" properties
non-optimal on your platform and controller clock?
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);
+
This patch is against old kernel. These were converted near 2 years ago
by the commit 4c5301abbf81 ("i2c: designware: Convert to use unified
device property API")
--
Jarkko
