On Mon, Jun 6, 2011 at 9:12 AM, David Jander <david@xxxxxxxxxxx> wrote:
> Signed-off-by: David Jander <david@xxxxxxxxxxx>
> ---
> .../devicetree/bindings/gpio/gpio_keys.txt | 49 ++++++++
> drivers/input/keyboard/gpio_keys.c | 131 ++++++++++++++++++++
> 2 files changed, 180 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/gpio/gpio_keys.txt
>
> diff --git a/Documentation/devicetree/bindings/gpio/gpio_keys.txt b/Documentation/devicetree/bindings/gpio/gpio_keys.txt
> new file mode 100644
> index 0000000..ff8ba2e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio_keys.txt
> @@ -0,0 +1,49 @@
> +Device-Tree bindings for input/gpio_keys.c keyboard driver
> +
> +Required properties:
> + - compatible = "linux,gpio-keys", "gpio-keys";
Drop linux,gpio-keys
> +
> +Optional properties:
> + - linux,autorepeat: Boolean, Enable auto repeat feature of Linux input
> + subsystem.
Drop the linux specific bits. Define the properties you need to
describe the behaviour or the keypad without making it linux-specific.
The binding should make sense regardless of either future changes to
the driver, or when using a different OS.
> +
> +Each button (key) is represented as a sub-node of "gpio-keys":
> +Subnode properties:
> +
> + - reg: GPIO number the key is bound to.
> + - label: Descriptive name of the key.
> + - linux,code: Keycode to emit.
Hmm, is there an OS-neutral way to specify this? There may not be,
but if there is then it should be looked at seriously.
> +
> +Optional subnode-properties:
> + - linux,active_low: Boolean flag to specify active-low GPIO input.
This isn't really a linux-specific thing. Perhaps use the name
"key-active-low".
Also, use '-' instead of '_' in property names.
> + - linux,input_type: Specify event type this button/key generates.
> + Default if unspecified is <1> == EV_KEY.
> + - linux,debounc_interval: Debouncing interval time in milliseconds.
> + Default if unspecified is 5.
Debounce is spelled with 2 'e's. :-) Also not linux specific.
Should be renamed. It would probably make sense to also allow a
debounce intervale property in the parent node. I suspect that a
single debounce interval value will simply be used by all keys in a
gpio-keys block.
> + - linux,can_disable: Boolean, specify if key can be disabled via
> + module parameter.
Is this really needed? Or even a good idea? It looks to be encoding
a driver-specific implementation detail that could potentially change
in the future.
> + - linux,wakeup: Boolean, button can wake-up the system.
Again, not linux-specific.
> +
> +Example nodes:
> +
> + gpio_keys {
> + compatible = "linux,gpio-keys", "gpio-keys";
> + #address-cells = <1>;
> + #size-cells = <0>;
> + linux,autorepeat;
> + button@20 {
> + label = "GPIO Key ESC";
> + linux,code = <1>;
> + reg = <0x20>;
> + linux,active_low;
> + linux,input_type = <1>;
> + };
> + button@21 {
> + label = "GPIO Key UP";
> + linux,code = <103>;
> + reg = <0x21>;
> + linux,active_low;
> + linux,input_type = <1>;
> + };
> + ...
> +
> diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
> index 987498e..4efd067 100644
> --- a/drivers/input/keyboard/gpio_keys.c
> +++ b/drivers/input/keyboard/gpio_keys.c
> @@ -3,6 +3,9 @@
> *
> * Copyright 2005 Phil Blundell
> *
> + * Added OF support:
> + * Copyright 2010 David Jander <david@xxxxxxxxxxx>
> + *
> * This program is free software; you can redistribute it and/or modify
> * it under the terms of the GNU General Public License version 2 as
> * published by the Free Software Foundation.
> @@ -25,6 +28,8 @@
> #include <linux/gpio_keys.h>
> #include <linux/workqueue.h>
> #include <linux/gpio.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
>
> struct gpio_button_data {
> struct gpio_keys_button *button;
> @@ -42,6 +47,7 @@ struct gpio_keys_drvdata {
> int (*enable)(struct device *dev);
> void (*disable)(struct device *dev);
> struct gpio_button_data data[0];
> + struct gpio_keys_platform_data *dyn_pdata;
> };
>
> /*
> @@ -442,18 +448,131 @@ static void gpio_keys_close(struct input_dev *input)
> ddata->disable(input->dev.parent);
> }
>
> +/*
> + * Handlers for alternative sources of platform_data
> + */
> +#ifdef CONFIG_OF
> +/*
> + * Translate OpenFirmware node properties into platform_data
> + */
> +static struct gpio_keys_platform_data *
> +gpio_keys_get_devtree_pdata(struct device *dev)
> +{
> + struct gpio_keys_platform_data *pdata;
> + struct device_node *node, *pp;
> + int i;
> + struct gpio_keys_button *buttons;
> + const u32 *reg;
> + int len;
> +
> + node = dev->of_node;
> + if (node == NULL)
> + return NULL;
> +
> + pdata = kzalloc(sizeof(struct gpio_keys_platform_data), GFP_KERNEL);
> + if (pdata == NULL) {
> + dev_err(dev, "Unable to allocate platform_data\n");
> + return NULL;
> + }
> +
> + pdata->rep = !!of_get_property(node, "linux,autorepeat", &len);
> +
> + /* First count the subnodes */
> + pdata->nbuttons = 0;
> + pp = NULL;
> + while ((pp = of_get_next_child(node, pp)))
> + pdata->nbuttons++;
> +
> + if (pdata->nbuttons == 0)
> + return NULL;
> +
> + buttons = kzalloc(pdata->nbuttons * sizeof(*buttons), GFP_KERNEL);
> + if (!buttons)
> + return NULL;
> +
> + pp = NULL;
> + i = 0;
> + while ((pp = of_get_next_child(node, pp))) {
> + const char *lbl;
> +
> + reg = of_get_property(pp, "reg", &len);
> + if (!reg) {
> + pdata->nbuttons--;
> + printk("Found button without reg\n");
> + continue;
> + }
> + buttons[i].gpio = reg[0];
> +
> + reg = of_get_property(pp, "linux,code", &len);
> + if (!reg) {
> + dev_err(dev, "Button without keycode: 0x%x\n", buttons[i].gpio);
> + return NULL;
> + }
> + buttons[i].code = reg[0];
> +
> + lbl = of_get_property(pp, "label", &len);
> + buttons[i].desc = (char *)lbl;
> +
> + buttons[i].active_low = !!of_get_property(pp, "linux,active_low", NULL);
> +
> + reg = of_get_property(pp, "linux,input_type", &len);
> + if (reg)
> + buttons[i].type = reg[0];
You need to do an endian conversion on device tree data. be32_to_cpup(reg);
> + else
> + buttons[i].type = EV_KEY;
> +
> + buttons[i].wakeup = !!of_get_property(pp, "linux,wakeup", NULL);
> +
> + reg = of_get_property(pp, "linux,debounc_interval", &len);
> + if (reg)
> + buttons[i].debounce_interval = reg[0];
> + else
> + buttons[i].debounce_interval = 5;
> +
> + buttons[i].can_disable = (bool)!!of_get_property(pp, "linux,can_disable", NULL);
> + i++;
> + }
> +
> + pdata->buttons = buttons;
> +
> + return pdata;
> +}
> +#else
> +static struct gpio_keys_platform_data *
> +gpio_keys_get_devtree_pdata(struct device *dev)
> +{
> + return NULL;
> +}
> +#endif
> +
> static int __devinit gpio_keys_probe(struct platform_device *pdev)
> {
> struct gpio_keys_drvdata *ddata;
> struct device *dev = &pdev->dev;
> struct gpio_keys_platform_data *pdata = dev->platform_data;
> + struct gpio_keys_platform_data *dyn_pdata = NULL;
> struct input_dev *input;
> int i, error;
> int wakeup = 0;
>
> + if (!pdata) {
> + pdata = gpio_keys_get_devtree_pdata(dev);
> + if (!pdata)
> + return -ENODEV;
> + /*
> + * Unlike normal platform_data, this is allocated
> + * dynamically and must be freed in the driver
> + */
> + dev->platform_data = pdata;
> + dyn_pdata = pdata;
> + }
> +
> ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
> pdata->nbuttons * sizeof(struct gpio_button_data),
> GFP_KERNEL);
> +
> + ddata->dyn_pdata = dyn_pdata;
> +
> input = input_allocate_device();
> if (!ddata || !input) {
> dev_err(dev, "failed to allocate state\n");
> @@ -565,12 +684,21 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev)
> cancel_work_sync(&ddata->data[i].work);
> gpio_free(pdata->buttons[i].gpio);
> }
> + if (ddata->dyn_pdata) {
> + kfree(pdata->buttons);
> + kfree(pdata);
> + }
>
> input_unregister_device(input);
>
> return 0;
> }
>
> +static struct of_device_id gpio_keys_of_match[] = {
> + { .compatible = "linux,gpio-keys", },
> + { .compatible = "gpio-keys", },
You don't need both values here. "gpio-keys" is fine.
> + {},
> +};
>
> #ifdef CONFIG_PM
> static int gpio_keys_suspend(struct device *dev)
> @@ -618,6 +746,8 @@ static const struct dev_pm_ops gpio_keys_pm_ops = {
> };
> #endif
>
> +MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
> +
> static struct platform_driver gpio_keys_device_driver = {
> .probe = gpio_keys_probe,
> .remove = __devexit_p(gpio_keys_remove),
> @@ -627,6 +757,7 @@ static struct platform_driver gpio_keys_device_driver = {
> #ifdef CONFIG_PM
> .pm = &gpio_keys_pm_ops,
> #endif
> + .of_match_table = gpio_keys_of_match,
> }
> };
>
> --
> 1.7.4.1
>
>
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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