Re: [PATCH] drivers: misc: add gpio wakeup driver

From: Fabio Estevam
Date: Tue Oct 01 2013 - 10:01:24 EST


Hi Daniel,

On Tue, Oct 1, 2013 at 10:55 AM, Daniel Mack <zonque@xxxxxxxxx> 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' ?

Please see Documentation/devicetree/bindings/gpio/gpio_keys.txt.

Regards,

Fabio Estevam


> 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@xxxxxxxxx>
> ---
> .../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@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Driver to wake up systems from GPIOs");
> +MODULE_ALIAS("platform:gpio-wakeup");
> --
> 1.8.3.1
>
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