On Tue, Oct 28, 2008 at 11:51:23PM -0400, Dmitry Torokhov wrote:
> On Tue, Oct 28, 2008 at 07:18:57PM +0900, Paul Mundt wrote:
> > On Tue, Oct 21, 2008 at 05:38:16PM +0900, Paul Mundt wrote:
> > > This implements an optional polling mode for the gpio_keys driver,
> > > necessary for GPIOs that are not able to generate IRQs.
> > >
> > > Polling mode is done device granular, and can not be toggled for
> > > individual GPIOs in order to maintain simplicity. Platforms with both
> > > IRQ capable and incapable GPIOs are required to register multiple
> > > times, once for each case.
> > >
> > >
> > > - input_unregister_device(input);
> > > + if (pdata->polling)
> > > + input_unregister_polled_device(poll_dev);
>
> You also need to do input_free_polled_device (but not input_free_device
> - yeah, I know, its confusing... The reason is that input_dev is
> refcounted while input_polled_dev is not).
Thanks, fixed.
> > > + else
> > > + input_unregister_device(poll_dev->input);
> > >
>
> I also concerned with unconditionally polling INPUT_POLLDEV for all
> users of gpio-keys. Maybe we could make polling support optional?
>
I thought that was what my patch was doing? I couldn't think of a clean
way to do it on a per-gpio basis, so the cleanest way seemed to be to
regster in polled and non-polled blocks. ie, polled devices will set
pdata->polling and register those for gpio_keys to set up a polled dev.
Devices that do not set pdata->polling will remain unaffected.
If you have some suggestions on how to toggle this on a per-gpio basis,
I am quite happy to change the code. If your concern is the select of
INPUT_POLLDEV, I can just select it from my platform code if you prefer.
This does mean that we would need nopped definitions in
linux/input-polldev.h though, or litter gpio_keys with ifdefs, which is
what I was trying to avoid in the first place. Let me know what you
prefer here, and I'll update accordingly.
For now, here is an updated version..
Signed-off-by: Paul Mundt <lethal@xxxxxxxxxxxx>
---
drivers/input/keyboard/Kconfig | 1
drivers/input/keyboard/gpio_keys.c | 92 ++++++++++++++++++++++++++++---------
include/linux/gpio_keys.h | 1
3 files changed, 73 insertions(+), 21 deletions(-)
diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index efd70a9..a8cefe9 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -283,6 +283,7 @@ config KEYBOARD_AAED2000
config KEYBOARD_GPIO
tristate "GPIO Buttons"
depends on GENERIC_GPIO
+ select INPUT_POLLDEV
help
This driver implements support for buttons connected
to GPIO pins of various CPUs (and some other chips).
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 05f3f43..e7a46f8 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -1,7 +1,8 @@
/*
- * Driver for keys on GPIO lines capable of generating interrupts.
+ * Driver for keys on GPIO lines, either IRQ-driven or polled.
*
* Copyright 2005 Phil Blundell
+ * Copyright 2008 Paul Mundt
*
* 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
@@ -9,7 +10,6 @@
*/
#include <linux/module.h>
-
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
@@ -22,7 +22,7 @@
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/gpio_keys.h>
-
+#include <linux/input-polldev.h>
#include <asm/gpio.h>
struct gpio_button_data {
@@ -32,7 +32,8 @@ struct gpio_button_data {
};
struct gpio_keys_drvdata {
- struct input_dev *input;
+ struct gpio_keys_platform_data *pdata;
+ struct input_polled_dev *poll_dev;
struct gpio_button_data data[0];
};
@@ -54,6 +55,33 @@ static void gpio_check_button(unsigned long _data)
gpio_keys_report_event(data);
}
+static void gpio_handle_button_event(struct gpio_keys_button *button,
+ struct gpio_button_data *bdata)
+{
+ if (button->debounce_interval)
+ mod_timer(&bdata->timer,
+ jiffies + msecs_to_jiffies(button->debounce_interval));
+ else
+ gpio_keys_report_event(bdata);
+}
+
+static void gpio_keys_poll(struct input_polled_dev *dev)
+{
+ struct gpio_keys_drvdata *ddata = dev->private;
+ struct gpio_keys_platform_data *pdata = ddata->pdata;
+ int i;
+
+ for (i = 0; i < pdata->nbuttons; i++) {
+ struct gpio_keys_button *button = &pdata->buttons[i];
+ struct gpio_button_data *bdata = &ddata->data[i];
+
+ bdata->input = dev->input;
+ bdata->button = button;
+
+ gpio_handle_button_event(button, bdata);
+ }
+}
+
static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
{
struct gpio_button_data *bdata = dev_id;
@@ -61,11 +89,7 @@ static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
BUG_ON(irq != gpio_to_irq(button->gpio));
- if (button->debounce_interval)
- mod_timer(&bdata->timer,
- jiffies + msecs_to_jiffies(button->debounce_interval));
- else
- gpio_keys_report_event(bdata);
+ gpio_handle_button_event(button, bdata);
return IRQ_HANDLED;
}
@@ -74,6 +98,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
{
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
struct gpio_keys_drvdata *ddata;
+ struct input_polled_dev *poll_dev;
struct input_dev *input;
int i, error;
int wakeup = 0;
@@ -81,14 +106,19 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
pdata->nbuttons * sizeof(struct gpio_button_data),
GFP_KERNEL);
- input = input_allocate_device();
- if (!ddata || !input) {
+ poll_dev = input_allocate_polled_device();
+ if (!ddata || !poll_dev) {
error = -ENOMEM;
goto fail1;
}
platform_set_drvdata(pdev, ddata);
+ poll_dev->private = ddata;
+ poll_dev->poll = gpio_keys_poll;
+ poll_dev->poll_interval = 50; /* msec */
+
+ input = poll_dev->input;
input->name = pdev->name;
input->phys = "gpio-keys/input0";
input->dev.parent = &pdev->dev;
@@ -98,7 +128,8 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
input->id.product = 0x0001;
input->id.version = 0x0100;
- ddata->input = input;
+ ddata->poll_dev = poll_dev;
+ ddata->pdata = pdata;
for (i = 0; i < pdata->nbuttons; i++) {
struct gpio_keys_button *button = &pdata->buttons[i];
@@ -127,6 +158,15 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
goto fail2;
}
+ input_set_capability(input, type, button->code);
+
+ /*
+ * Skip the IRQ setup and wakeup source initialization if
+ * we are going to be polled.
+ */
+ if (pdata->polling)
+ continue;
+
irq = gpio_to_irq(button->gpio);
if (irq < 0) {
error = irq;
@@ -151,11 +191,12 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
if (button->wakeup)
wakeup = 1;
-
- input_set_capability(input, type, button->code);
}
- error = input_register_device(input);
+ if (pdata->polling)
+ error = input_register_polled_device(poll_dev);
+ else
+ error = input_register_device(input);
if (error) {
pr_err("gpio-keys: Unable to register input device, "
"error: %d\n", error);
@@ -168,7 +209,9 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
fail2:
while (--i >= 0) {
- free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
+ if (!pdata->polling)
+ free_irq(gpio_to_irq(pdata->buttons[i].gpio),
+ &ddata->data[i]);
if (pdata->buttons[i].debounce_interval)
del_timer_sync(&ddata->data[i].timer);
gpio_free(pdata->buttons[i].gpio);
@@ -176,7 +219,7 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, NULL);
fail1:
- input_free_device(input);
+ input_free_polled_device(poll_dev);
kfree(ddata);
return error;
@@ -186,20 +229,27 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev)
{
struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
- struct input_dev *input = ddata->input;
+ struct input_polled_dev *poll_dev = ddata->poll_dev;
int i;
device_init_wakeup(&pdev->dev, 0);
for (i = 0; i < pdata->nbuttons; i++) {
- int irq = gpio_to_irq(pdata->buttons[i].gpio);
- free_irq(irq, &ddata->data[i]);
+ if (!pdata->polling) {
+ int irq = gpio_to_irq(pdata->buttons[i].gpio);
+ free_irq(irq, &ddata->data[i]);
+ }
+
if (pdata->buttons[i].debounce_interval)
del_timer_sync(&ddata->data[i].timer);
gpio_free(pdata->buttons[i].gpio);
}
- input_unregister_device(input);
+ if (pdata->polling) {
+ input_unregister_polled_device(poll_dev);
+ input_free_polled_device(poll_dev);
+ } else
+ input_unregister_device(poll_dev->input);
return 0;
}
diff --git a/include/linux/gpio_keys.h b/include/linux/gpio_keys.h
index ec6ecd7..e869752 100644
--- a/include/linux/gpio_keys.h
+++ b/include/linux/gpio_keys.h
@@ -15,6 +15,7 @@ struct gpio_keys_button {
struct gpio_keys_platform_data {
struct gpio_keys_button *buttons;
int nbuttons;
+ int polling; /* force polling mode */
};
#endif
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