Re: [PATCH 3/3] max7359_keypad: implement DT bindings

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Thu, May 14, 2015 at 05:38:03AM +0300, Evgeniy Dushistov wrote:
> max7359_keypad: implement DT bindings
> 
> Signed-off-by: Evgeniy A. Dushistov <dushistov@mail.ru>
> ---
>  .../devicetree/bindings/input/max7359-keypad.txt   | 33 ++++++++++++
>  drivers/input/keyboard/max7359_keypad.c            | 60 ++++++++++++++++++++--
>  2 files changed, 90 insertions(+), 3 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/input/max7359-keypad.txt
> 
> diff --git a/Documentation/devicetree/bindings/input/max7359-keypad.txt b/Documentation/devicetree/bindings/input/max7359-keypad.txt
> new file mode 100644
> index 0000000..0a3c381
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/max7359-keypad.txt
> @@ -0,0 +1,33 @@
> +* MAX7359 keypda device tree bindings
> +
> +Required Properties:
> +- compatible:		Should be "maxim,max7359"
> +- linux,keymap:		The definition can be found at
> +			bindings/input/matrix-keymap.txt
> +
> +Optional Properties:
> +- maxim,debounce_reg: u8, in short allow control debounce,
> +see max7359 datasheet for details
> +- maxim,ports_reg: u8, in short allow control what pin used,
> +and what pins should be configured as GPIO
> +
> +Example:
> +	max7359_keypad@38 {
> +		compatible = "maxim,max7359";
> +		reg = <0x38>;
> +		interrupts = <28 IRQ_TYPE_LEVEL_LOW>;/*gpio_156*/
> +		interrupt-parent = <&gpio5>;
> +		maxim,debounce_reg = /bits/ 8 <0x5F>;
> +		maxim,ports_reg = /bits/ 8 <0xFF>;

Specifying exact size for properties is quite uncommon; I think the
usual recommendation is is to use the "standard" u32 and validate the
range in parser function.

> +		linux,keymap = <
> +		MATRIX_KEY(0, 0, KEY_RESERVED) /*row 0 not used*/
> +		MATRIX_KEY(0, 1, KEY_RESERVED)
> +		MATRIX_KEY(0, 2, KEY_RESERVED)
> +		MATRIX_KEY(0, 3, KEY_RESERVED)
> +		MATRIX_KEY(0, 4, KEY_RESERVED)
> +		MATRIX_KEY(0, 5, KEY_RESERVED)
> +		MATRIX_KEY(0, 6, KEY_RESERVED)
> +		MATRIX_KEY(0, 7, KEY_RESERVED)
> +		...

Indent one more level? Also, maybe fill with something other than
KEY_RESERVED?

> +		>;
> +	};
> diff --git a/drivers/input/keyboard/max7359_keypad.c b/drivers/input/keyboard/max7359_keypad.c
> index 5091133..0164f2e 100644
> --- a/drivers/input/keyboard/max7359_keypad.c
> +++ b/drivers/input/keyboard/max7359_keypad.c
> @@ -20,6 +20,7 @@
>  #include <linux/pm.h>
>  #include <linux/input.h>
>  #include <linux/input/matrix_keypad.h>
> +#include <linux/of.h>
>  
>  #define MAX7359_MAX_KEY_ROWS	8
>  #define MAX7359_MAX_KEY_COLS	8
> @@ -64,6 +65,11 @@ struct max7359_keypad {
>  	struct i2c_client *client;
>  };
>  
> +struct max7359_initial_state {
> +	u8 debounce_val;
> +	u8 ports_val;
> +};
> +
>  static int max7359_write_reg(struct i2c_client *client, u8 reg, u8 val)
>  {
>  	int ret = i2c_smbus_write_byte_data(client, reg, val);
> @@ -143,24 +149,54 @@ static void max7359_close(struct input_dev *dev)
>  	max7359_fall_deepsleep(keypad->client);
>  }
>  
> -static void max7359_initialize(struct i2c_client *client)
> +static void max7359_initialize(struct i2c_client *client,
> +			       const struct max7359_initial_state *init_state)
>  {
>  	max7359_write_reg(client, MAX7359_REG_CONFIG,
>  		MAX7359_CFG_KEY_RELEASE | /* Key release enable */
>  		MAX7359_CFG_WAKEUP); /* Key press wakeup enable */
>  
>  	/* Full key-scan functionality */
> -	max7359_write_reg(client, MAX7359_REG_DEBOUNCE, 0x1F);
> +	max7359_write_reg(client, MAX7359_REG_DEBOUNCE,
> +			  init_state->debounce_val);
>  
>  	/* nINT asserts every debounce cycles */
>  	max7359_write_reg(client, MAX7359_REG_INTERRUPT, 0x01);
> +	max7359_write_reg(client, MAX7359_REG_PORTS, init_state->ports_val);
>  
>  	max7359_fall_deepsleep(client);
>  }
>  
> +#ifdef CONFIG_OF
> +static int max7359_parse_dt(struct device *dev,
> +			    struct max7359_initial_state *init_state)
> +{
> +	struct device_node *np = dev->of_node;
> +	u8 prop;
> +
> +	if (!of_property_read_u8(np, "maxim,debounce_reg", &prop))
> +		init_state->debounce_val = prop;
> +
> +	if (!of_property_read_u8(np, "maxim,ports_reg", &prop))
> +		init_state->ports_val = prop;
> +
> +	return 0;
> +}
> +#else
> +static inline int max7359_parse_dt(struct device *dev,
> +				   struct max7359_initial_state *init_state)
> +{
> +	return -EINVAL;
> +}
> +#endif
> +
>  static int max7359_probe(struct i2c_client *client,
>  					const struct i2c_device_id *id)
>  {
> +	struct max7359_initial_state init_state = {
> +		.debounce_val = 0x1F,
> +		.ports_val = 0xFE,
> +	};
>  	const struct matrix_keymap_data *keymap_data =
>  			dev_get_platdata(&client->dev);
>  	struct max7359_keypad *keypad;
> @@ -181,6 +217,15 @@ static int max7359_probe(struct i2c_client *client,
>  	}
>  
>  	dev_dbg(&client->dev, "keys FIFO is 0x%02x\n", ret);
> +	if (!keymap_data) {
> +		error = max7359_parse_dt(&client->dev, &init_state);
> +		if (error) {
> +			dev_err(&client->dev, "platform data null, and no DT data\n");
> +			return error;

Both debounce and ports values are optional and we'll fail building
keymap if there are no platform data nor device tree data, so I would
drop this check and the stub for max7359_parse_dt() as well - we have
stubs for property parsing anyway.

> +		}
> +		dev_dbg(&client->dev, "Init vals: debounce %X, ports %X\n",
> +			init_state.debounce_val, init_state.ports_val);
> +	}
>  
>  	keypad = devm_kzalloc(&client->dev, sizeof(struct max7359_keypad),
>  			      GFP_KERNEL);
> @@ -239,7 +284,7 @@ static int max7359_probe(struct i2c_client *client,
>  	}
>  
>  	/* Initialize MAX7359 */
> -	max7359_initialize(client);
> +	max7359_initialize(client, &init_state);
>  
>  	i2c_set_clientdata(client, keypad);
>  	device_init_wakeup(&client->dev, 1);
> @@ -282,10 +327,19 @@ static const struct i2c_device_id max7359_ids[] = {
>  };
>  MODULE_DEVICE_TABLE(i2c, max7359_ids);
>  
> +#ifdef CONFIG_OF
> +static const struct of_device_id max7359_dt_match[] = {
> +	{ .compatible = "maxim,max7359" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, max7359_dt_match);
> +#endif
> +
>  static struct i2c_driver max7359_i2c_driver = {
>  	.driver = {
>  		.name = "max7359",
>  		.pm   = &max7359_pm,
> +		.of_match_table = of_match_ptr(max7359_dt_match),
>  	},
>  	.probe		= max7359_probe,
>  	.id_table	= max7359_ids,
> -- 
> 2.3.6
> 
> -- 
> /Evgeniy

Thanks.

-- 
Dmitry