input: matrix-keymap: Add function to read the new DT binding

We now have a binding which adds two parameters to the matrix keypad DT
node. This is separate from the GPIO-driven matrix keypad binding, and
unfortunately incompatible, since that uses row-gpios/col-gpios for the
row and column counts.

So the easiest option here is to provide a function for non-GPIO drivers
to use to decode the binding.

Note: We could in fact create an entirely separate structure to hold
these two fields, but it does not seem worth it, yet. If we have more
parameters then we can add this, and then refactor each driver to hold
such a structure.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com> (v2)
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/input/keyboard/lpc32xx-keys.c b/drivers/input/keyboard/lpc32xx-keys.c
index 1b8add6cfb9d..42181435fe67 100644
--- a/drivers/input/keyboard/lpc32xx-keys.c
+++ b/drivers/input/keyboard/lpc32xx-keys.c
@@ -144,12 +144,13 @@ static int lpc32xx_parse_dt(struct device *dev,
 {
 	struct device_node *np = dev->of_node;
 	u32 rows = 0, columns = 0;
+	int err;
 
-	of_property_read_u32(np, "keypad,num-rows", &rows);
-	of_property_read_u32(np, "keypad,num-columns", &columns);
-	if (!rows || rows != columns) {
-		dev_err(dev,
-			"rows and columns must be specified and be equal!\n");
+	err = matrix_keypad_parse_of_params(dev, &rows, &columns);
+	if (err)
+		return err;
+	if (rows != columns) {
+		dev_err(dev, "rows and columns must be equal!\n");
 		return -EINVAL;
 	}