Hi Grygorii,

Grygorii Strashko [off-list ref] wrote on Wed, 1 Sep 2021
22:26:25 +0300:

On 25/08/2021 18:25, Miquel Raynal wrote:

quoted

Introduce a new compatible that has another set of driver data,
targeting am437x SoCs with a magnetic reader instead of the
touchscreen and a more featureful set of registers.

Co-developed-by: Jason Reeder <redacted>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Jason Reeder <redacted>
---
  drivers/mfd/ti_am335x_tscadc.c       | 43 ++++++++++++++++++++++------
  include/linux/mfd/ti_am335x_tscadc.h |  9 +++++-
  2 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index 1a30610dc65f..f4f6b9db4d2a 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c

@@ -122,9 +122,9 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
  	const __be32 *cur;
  	struct clk *clk;
  	u32 val;
-	bool use_tsc = false;
+	bool use_tsc = false, use_mag = false;
  	int tscmag_wires = 0, adc_channels = 0, readouts = 0, cell_idx = 0;
-	int total_channels, err;
+	int mag_tracks = 0, total_channels, err;  
  >   	/* Allocate memory for device */  
  	tscadc = devm_kzalloc(&pdev->dev, sizeof(*tscadc), GFP_KERNEL);

@@ -146,6 +146,12 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
  		of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
  		if (tscmag_wires)
  			use_tsc = true;
+	} else {
+		node = of_get_child_by_name(pdev->dev.of_node, "mag");
+		of_property_read_u32(node, "ti,tracks", &mag_tracks);  

"ti,tracks" seems undocumented?

Well that's true and almost on purpose, I am not focusing on the
magnetic reader feature, it is not supported, I don't have one, I don't
plan to add support for it. But in the driver I need to know how many
"tracks" are unavailable for the ADC in order to implement the entire
logic (this block comes from TI and the naming from Jason Reeder).

I am not comfortable writing a binding file for a device that I won't
use, it's the best way to miss something and have stable broken
bindings in the future. So I assumed it was not a big deal to have this
property in the code, which may be updated/removed/enhanced later if
needed without having to mess with the code too much. What do you think?

Thanks,
Miquèl