diff mbox

[v3,4/4] i2c: qup: Add command-line parameter to override SCL frequency

Message ID 1525968837-13381-5-git-send-email-austinwc@codeaurora.org (mailing list archive)
State Not Applicable, archived
Delegated to: Andy Gross
Headers show

Commit Message

Austin Christ May 10, 2018, 4:13 p.m. UTC 
Add a module parameter to override SCL frequency provided by firmware.
This can be useful when testing spec compliance for I2C modes or when
debugging issues across multiple operating frequencies.

Signed-off-by: Austin Christ <austinwc@codeaurora.org>
Reviewed-by: Sricharan R <sricharan@codeaurora.org>
---
v1:
	- Initial
v2:
	- No changes
v3:
	- No changes
---
 drivers/i2c/busses/i2c-qup.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

Comments

Andy Gross May 25, 2018, 8:30 p.m. UTC | #1 
On Thu, May 10, 2018 at 10:13:57AM -0600, Austin Christ wrote:
> Add a module parameter to override SCL frequency provided by firmware.
> This can be useful when testing spec compliance for I2C modes or when
> debugging issues across multiple operating frequencies.
> 
> Signed-off-by: Austin Christ <austinwc@codeaurora.org>
> Reviewed-by: Sricharan R <sricharan@codeaurora.org>
> ---

Looks good to me.

Reviewed-by: Andy Gross <andy.gross@linaro.org>
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diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index f87f29f..da4cc57 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -155,6 +155,10 @@ 
 /* TAG length for DATA READ in RX FIFO  */
 #define READ_RX_TAGS_LEN		2
 
+static unsigned int scl_freq;
+module_param_named(scl_freq, scl_freq, uint, 0444);
+MODULE_PARM_DESC(scl_freq, "SCL frequency override");
+
 /*
  * count: no of blocks
  * pos: current block number
@@ -1682,11 +1686,16 @@  static int qup_i2c_probe(struct platform_device *pdev)
 	init_completion(&qup->xfer);
 	platform_set_drvdata(pdev, qup);
 
-	ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq);
-	if (ret) {
-		dev_notice(qup->dev, "using default clock-frequency %d",
-			DEFAULT_CLK_FREQ);
-	}
+	if (scl_freq) {
+		dev_notice(qup->dev, "Using override frequency of %u\n", scl_freq);
+		clk_freq = scl_freq;
+	} else {
+		ret = device_property_read_u32(qup->dev, "clock-frequency", &clk_freq);
+		if (ret) {
+			dev_notice(qup->dev, "using default clock-frequency %d",
+				DEFAULT_CLK_FREQ);
+		}
+	}
 
 	if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-v1.1.1")) {
 		qup->adap.algo = &qup_i2c_algo;