Hi Rob,

Thanks for the comments.

On Fri, Oct 19, 2012 at 18:27:21, Rob Herring wrote:

On 10/19/2012 02:06 AM, AnilKumar Ch wrote:

quoted

Add device tree support to matrix keypad driver and usage details
are added to device tree documentation. Driver was tested on AM335x
EVM.

Signed-off-by: AnilKumar Ch <redacted>
---
 .../devicetree/bindings/input/matrix-keypad.txt    |   52 ++++++++++
 drivers/input/keyboard/matrix_keypad.c             |  104 +++++++++++++++++++-
 2 files changed, 155 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/input/matrix-keypad.txt

diff --git a/Documentation/devicetree/bindings/input/matrix-keypad.txt b/Documentation/devicetree/bindings/input/matrix-keypad.txt
new file mode 100644
index 0000000..50aaa6e
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/matrix-keypad.txt

@@ -0,0 +1,52 @@
+* GPIO driven matrix keypad device tree bindings
+
+GPIO driven matrix keypad is used to interface a SoC with a matrix keypad.
+The matrix keypad supports multiple row and column lines, a key can be
+placed at each intersection of a unique row and a unique column. The matrix
+keypad can sense a key-press and key-release by means of GPIO lines and
+report the event using GPIO interrupts to the cpu.
+
+Required Properties:
+- compatible:		Should be "matix-keypad"

How about gpio-matrix-keypad?

More meaningful, changed

quoted

+- keypad,num-row-gpios:	Number of row lines connected to the keypad
+			controller.
+- keypad,num-col-gpios:	Number of column lines connected to the keypad
+			controller.

Isn't the number of gpios just the count of gpios listed below? So you
don't need these props.

Removed

quoted

+- row-gpios:		List of gpios used as row lines. The gpio specifier
+			for this property depends on the gpio controller to
+			which these row lines are connected.
+- col-gpios:		List of gpios used as column lines. The gpio specifier
+			for this property depends on the gpio controller to
+			which these column lines are connected.
+
+Optional Properties:
+- linux,no-autorepeat:	do no enable autorepeat feature.
+- linux,wakeup:		use any event on keypad as wakeup event.
+- debounce-delay-ms:	debounce interval in milliseconds
+- col-scan-delay-us:	delay, measured in microseconds, that is needed
+			before we can scan keypad after activating column gpio
+- clustered-irq:	have clustered irq number
+- clustered-irq-flags:	have clustered irq flags

It's not clear what clustered means here. If I have to go read Linux
code to understand, you are doing it wrong. Describe the h/w, not Linux
data structs.

I have added based on pdata of the driver, I am not using these
parameters because AM335x-EVM have different interrupts for all
gpio pins.

clustered-irq: combined irq source for the whole matrix keypad,
like all gpio keys are connected to a gpio expander

quoted

+
+Example:
+	matrix-keypad {
+		compatible = "matrix-keypad";
+		keypad,num-row-gpios = <3>;
+		keypad,num-col-gpios = <2>;
+		debounce-delay-ms = <5>;
+		col-scan-delay-us = <2>;
+
+		row-gpios = <&gpio2 25 0
+			     &gpio2 26 0
+			     &gpio2 27 0>;
+
+		col-gpios = <&gpio2 21 0
+			     &gpio2 22 0>;
+
+		linux,keymap = <0x0000008B
+				0x0100009E
+				0x02000069
+				0x0001006A
+				0x0101001C
+				0x0201006C>;
+	};

diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c
index 18b7237..39e480d 100644
--- a/drivers/input/keyboard/matrix_keypad.c
+++ b/drivers/input/keyboard/matrix_keypad.c

@@ -23,6 +23,9 @@
 #include <linux/gpio.h>
 #include <linux/input/matrix_keypad.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_platform.h>
 
 struct matrix_keypad {
 	const struct matrix_keypad_platform_data *pdata;

@@ -394,6 +397,91 @@ static void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
 		gpio_free(pdata->col_gpios[i]);
 }
 
+#ifdef CONFIG_OF
+static
+struct matrix_keypad_platform_data *matrix_keypad_parse_dt(struct device *dev)
+{
+	struct matrix_keypad_platform_data *pdata;
+	struct matrix_keymap_data *keymap_data;
+	struct device_node *np = dev->of_node;
+	struct property *prop;
+	int key_count = 0, length, row, col;
+	uint32_t *keymap;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata) {
+		dev_err(dev, "could not allocate memory for platform data\n");
+		return NULL;
+	}
+
+	of_property_read_u32(np, "keypad,num-row-gpios", &pdata->num_row_gpios);
+	of_property_read_u32(np, "keypad,num-col-gpios", &pdata->num_col_gpios);
+	if (!pdata->num_row_gpios || !pdata->num_col_gpios) {
+		dev_err(dev, "number of keypad rows/columns not specified\n");
+		return NULL;
+	}
+
+	keymap_data = devm_kzalloc(dev, sizeof(*keymap_data), GFP_KERNEL);
+	if (!keymap_data) {
+		dev_err(dev, "could not allocate memory for keymap data\n");
+		return NULL;
+	}
+	pdata->keymap_data = keymap_data;
+
+	prop = of_find_property(np, "linux,keymap", &length);
+	if (!prop)
+		return NULL;
+
+	key_count = length / sizeof(u32);
+	keymap_data->keymap_size = key_count;
+	keymap = devm_kzalloc(dev, sizeof(uint32_t) * key_count, GFP_KERNEL);
+	if (!keymap) {
+		dev_err(dev, "could not allocate memory for keymap\n");
+		return NULL;
+	}
+	keymap_data->keymap = keymap;
+
+	of_property_read_u32_array(np, "linux,keymap", keymap, key_count);

Can't you use matrix_keypad_parse_of_keymap?

To use this API matrix_keypad_build_keymap() in probe should
be removed if so non-dt case have the problem.

quoted

+
+	if (of_get_property(np, "linux,no-autorepeat", NULL))
+		pdata->no_autorepeat = true;
+	if (of_get_property(np, "linux,wakeup", NULL))
+		pdata->wakeup = true;
+	if (of_get_property(np, "gpio-activelow", NULL))
+		pdata->active_low = true;
+
+	of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
+	of_property_read_u32(np, "col-scan-delay-us",
+						&pdata->col_scan_delay_us);
+	of_property_read_u32(np, "clustered-irq", &pdata->clustered_irq);
+	of_property_read_u32(np, "clustered-irq-flags",
+						&pdata->clustered_irq_flags);
+
+	pdata->row_gpios = devm_kzalloc(dev, sizeof(unsigned int) *
+					pdata->num_row_gpios, GFP_KERNEL);
+	pdata->col_gpios = devm_kzalloc(dev, sizeof(unsigned int) *
+					pdata->num_col_gpios, GFP_KERNEL);

There's kind of a lot of allocations in this function. It would be good
to combine some of them.

These are non-const aliases, so these are required.

quoted

+	if (!pdata->row_gpios || !pdata->col_gpios) {
+		dev_err(dev, "could not allocate memory for gpios\n");
+		return NULL;
+	}
+
+	for (row = 0; row < pdata->num_row_gpios; row++)
+		pdata->row_gpios[row] = of_get_named_gpio(np, "row-gpios", row);
+
+	for (col = 0; col < pdata->num_col_gpios; col++)
+		pdata->col_gpios[col] = of_get_named_gpio(np, "col-gpios", col);
+
+	return pdata;
+}
+#else
+static
+struct matrix_keypad_platform_data *matrix_keypad_parse_dt(struct device *dev)
+{
+	return NULL;
+}
+#endif
+
 static int __devinit matrix_keypad_probe(struct platform_device *pdev)
 {
 	const struct matrix_keypad_platform_data *pdata;

@@ -404,7 +492,10 @@ static int __devinit matrix_keypad_probe(struct platform_device *pdev)
 	size_t keymap_size;
 	int err;
 
-	pdata = pdev->dev.platform_data;
+	if (pdev->dev.of_node)
+		pdata = matrix_keypad_parse_dt(&pdev->dev);
+	else
+		pdata = pdev->dev.platform_data;
 	if (!pdata) {
 		dev_err(&pdev->dev, "no platform data defined\n");
 		return -EINVAL;

@@ -488,6 +579,16 @@ static int __devexit matrix_keypad_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id matrix_keypad_dt_match[] = {
+	{ .compatible = "matrix-keypad" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
+#else
+#define matrix_keypad_dt_match NULL
+#endif

Use of_match_ptr() and remove the #else

Changed.

Thanks
AnilKumar