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    SubjectRe: [PATCH] drivers: misc: add gpio wakeup driver
    Hi Fabio,

    On 01.10.2013 16:01, Fabio Estevam wrote:
    > On Tue, Oct 1, 2013 at 10:55 AM, Daniel Mack <zonque@gmail.com> wrote:
    >> This patch adds a very simple driver that enables GPIO lines as wakeup
    >> sources. It only operates on information passed in via DT, and depends
    >
    > Isn't it the same as the existing 'gpio-key,wakeup' ?

    Of course, I know the gpio-input driver can provide similar
    functionality. My intention was just provide a way to wake up the system
    without registering an input device for signals nobody is interested in
    eventually.

    Don't know if that's reason enough to add a new driver though.


    Thanks,
    Daniel



    >
    >> on CONFIG_OF && CONFIG_PM_SLEEP. It can for example be used to connect
    >> wake-on-LAN (WOL) signals or other electric wakeup networks.
    >>
    >> The driver accepts a list of GPIO nodes and claims them along with their
    >> interrupt line. During suspend, the interrupts will be enabled and
    >> selected as wakeup source. The driver doesn't do anything else with the
    >> GPIO lines, and will ignore occured interrupts silently.
    >>
    >> Signed-off-by: Daniel Mack <zonque@gmail.com>
    >> ---
    >> .../devicetree/bindings/misc/gpio-wakeup.txt | 16 ++
    >> drivers/misc/Kconfig | 8 +
    >> drivers/misc/Makefile | 1 +
    >> drivers/misc/gpio-wakeup.c | 162 +++++++++++++++++++++
    >> 4 files changed, 187 insertions(+)
    >> create mode 100644 Documentation/devicetree/bindings/misc/gpio-wakeup.txt
    >> create mode 100644 drivers/misc/gpio-wakeup.c
    >>
    >> diff --git a/Documentation/devicetree/bindings/misc/gpio-wakeup.txt b/Documentation/devicetree/bindings/misc/gpio-wakeup.txt
    >> new file mode 100644
    >> index 0000000..6aacd0f
    >> --- /dev/null
    >> +++ b/Documentation/devicetree/bindings/misc/gpio-wakeup.txt
    >> @@ -0,0 +1,16 @@
    >> +GPIO WAKEUP DRIVER BINDINGS
    >> +
    >> +Required:
    >> +
    >> + compatible: Must be "gpio-wakeup"
    >> + gpios: At list of GPIO nodes that are enabled as wakeup
    >> + sources.
    >> +
    >> +
    >> +Example:
    >> +
    >> + wake_up {
    >> + compatible = "gpio-wakeup";
    >> + gpios = <&gpio0 19 0>;
    >> + };
    >> +
    >> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
    >> index 8dacd4c..c089280 100644
    >> --- a/drivers/misc/Kconfig
    >> +++ b/drivers/misc/Kconfig
    >> @@ -528,6 +528,14 @@ config SRAM
    >> the genalloc API. It is supposed to be used for small on-chip SRAM
    >> areas found on many SoCs.
    >>
    >> +config GPIO_WAKEUP
    >> + tristate "GPIO wakeup driver"
    >> + depends on PM_SLEEP && OF
    >> + help
    >> + Say Y to build a driver that can wake up a system from GPIO
    >> + lines. See Documentation/devicetree/bindings/gpio-wakeup.txt
    >> + for binding details.
    >> +
    >> source "drivers/misc/c2port/Kconfig"
    >> source "drivers/misc/eeprom/Kconfig"
    >> source "drivers/misc/cb710/Kconfig"
    >> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
    >> index c235d5b..ee4df84 100644
    >> --- a/drivers/misc/Makefile
    >> +++ b/drivers/misc/Makefile
    >> @@ -53,3 +53,4 @@ obj-$(CONFIG_INTEL_MEI) += mei/
    >> obj-$(CONFIG_VMWARE_VMCI) += vmw_vmci/
    >> obj-$(CONFIG_LATTICE_ECP3_CONFIG) += lattice-ecp3-config.o
    >> obj-$(CONFIG_SRAM) += sram.o
    >> +obj-$(CONFIG_GPIO_WAKEUP) += gpio-wakeup.o
    >> diff --git a/drivers/misc/gpio-wakeup.c b/drivers/misc/gpio-wakeup.c
    >> new file mode 100644
    >> index 0000000..3c1ef88
    >> --- /dev/null
    >> +++ b/drivers/misc/gpio-wakeup.c
    >> @@ -0,0 +1,162 @@
    >> +/*
    >> + * Driver to select GPIO lines as wakeup sources from DT.
    >> + *
    >> + * Copyright 2013 Daniel Mack
    >> + *
    >> + * 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.
    >> + */
    >> +
    >> +#include <linux/module.h>
    >> +
    >> +#include <linux/init.h>
    >> +#include <linux/interrupt.h>
    >> +#include <linux/irq.h>
    >> +#include <linux/pm.h>
    >> +#include <linux/slab.h>
    >> +#include <linux/platform_device.h>
    >> +#include <linux/gpio.h>
    >> +#include <linux/of_platform.h>
    >> +#include <linux/of_gpio.h>
    >> +
    >> +struct gpio_wakeup_priv {
    >> + unsigned int count;
    >> + unsigned int irq[0];
    >> +};
    >> +
    >> +static irqreturn_t gpio_wakeup_isr(int irq, void *dev_id)
    >> +{
    >> + return IRQ_HANDLED;
    >> +}
    >> +
    >> +static int gpio_wakeup_probe(struct platform_device *pdev)
    >> +{
    >> + int ret, count, i;
    >> + struct gpio_wakeup_priv *priv;
    >> + struct device *dev = &pdev->dev;
    >> + struct device_node *np = dev->of_node;
    >> +
    >> + if (!np)
    >> + return -EINVAL;
    >> +
    >> + count = of_gpio_count(np);
    >> + if (count == 0)
    >> + return -EINVAL;
    >> +
    >> + priv = devm_kzalloc(dev, sizeof(*priv) +
    >> + sizeof(int) * count, GFP_KERNEL);
    >> + if (!priv)
    >> + return -ENOMEM;
    >> +
    >> + for (i = 0; i < count; i++) {
    >> + unsigned int gpio, irq;
    >> +
    >> + priv->irq[i] = -EINVAL;
    >> +
    >> + gpio = of_get_gpio(np, i);
    >> + if (gpio < 0) {
    >> + dev_warn(dev, "Unable to get gpio #%d\n", i);
    >> + continue;
    >> + }
    >> +
    >> + irq = gpio_to_irq(gpio);
    >> + if (irq < 0) {
    >> + dev_warn(dev, "Can't map GPIO %d to an IRQ\n", gpio);
    >> + continue;
    >> + }
    >> +
    >> + ret = devm_gpio_request_one(dev, gpio, GPIOF_IN, pdev->name);
    >> + if (ret < 0) {
    >> + dev_warn(dev, "Unable to request GPIO %d: %d\n",
    >> + gpio, ret);
    >> + continue;
    >> + }
    >> +
    >> + ret = devm_request_irq(dev, irq, gpio_wakeup_isr,
    >> + IRQF_TRIGGER_RISING |
    >> + IRQF_TRIGGER_FALLING,
    >> + pdev->name, NULL);
    >> + if (ret < 0) {
    >> + dev_warn(dev, "Unable to request IRQ %d\n", irq);
    >> + continue;
    >> + }
    >> +
    >> + disable_irq(irq);
    >> + priv->irq[i] = irq;
    >> +
    >> + dev_info(dev, "Adding GPIO %d (IRQ %d) to wakeup sources\n",
    >> + gpio, irq);
    >> + }
    >> +
    >> + priv->count = count;
    >> + device_init_wakeup(dev, 1);
    >> + platform_set_drvdata(pdev, priv);
    >> +
    >> + return 0;
    >> +}
    >> +
    >> +static int gpio_wakeup_suspend(struct device *dev)
    >> +{
    >> + struct gpio_wakeup_priv *priv = dev_get_drvdata(dev);
    >> + int i;
    >> +
    >> + for (i = 0; i < priv->count; i++)
    >> + if (priv->irq[i] >= 0) {
    >> + enable_irq(priv->irq[i]);
    >> + enable_irq_wake(priv->irq[i]);
    >> + }
    >> +
    >> + return 0;
    >> +}
    >> +
    >> +static int gpio_wakeup_resume(struct device *dev)
    >> +{
    >> + struct gpio_wakeup_priv *priv = dev_get_drvdata(dev);
    >> + int i;
    >> +
    >> + for (i = 0; i < priv->count; i++)
    >> + if (priv->irq[i] >= 0) {
    >> + disable_irq_wake(priv->irq[i]);
    >> + disable_irq(priv->irq[i]);
    >> + }
    >> +
    >> + return 0;
    >> +}
    >> +
    >> +static SIMPLE_DEV_PM_OPS(gpio_wakeup_pm_ops,
    >> + gpio_wakeup_suspend, gpio_wakeup_resume);
    >> +
    >> +static struct of_device_id gpio_wakeup_of_match[] = {
    >> + { .compatible = "gpio-wakeup", },
    >> + { },
    >> +};
    >> +MODULE_DEVICE_TABLE(of, gpio_wakeup_of_match);
    >> +
    >> +static struct platform_driver gpio_wakeup_driver = {
    >> + .probe = gpio_wakeup_probe,
    >> + .driver = {
    >> + .name = "gpio-wakeup",
    >> + .owner = THIS_MODULE,
    >> + .pm = &gpio_wakeup_pm_ops,
    >> + .of_match_table = of_match_ptr(gpio_wakeup_of_match),
    >> + }
    >> +};
    >> +
    >> +static int __init gpio_wakeup_init(void)
    >> +{
    >> + return platform_driver_register(&gpio_wakeup_driver);
    >> +}
    >> +
    >> +static void __exit gpio_wakeup_exit(void)
    >> +{
    >> + platform_driver_unregister(&gpio_wakeup_driver);
    >> +}
    >> +
    >> +late_initcall(gpio_wakeup_init);
    >> +module_exit(gpio_wakeup_exit);
    >> +
    >> +MODULE_LICENSE("GPL");
    >> +MODULE_AUTHOR("Daniel Mack <zonque@gmail.com>");
    >> +MODULE_DESCRIPTION("Driver to wake up systems from GPIOs");
    >> +MODULE_ALIAS("platform:gpio-wakeup");
    >> --
    >> 1.8.3.1
    >>
    >> --
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