[PATCH] extcon: gpio: Add the support for Device tree bindings

From: Chanwoo Choi
Date: Fri Oct 02 2015 - 02:15:27 EST

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This patch adds the support for Device tree bindings of extcon-gpio driver.
The extcon-gpio device tree node must include the both 'extcon-id' and
'extcon-gpio' property.

For exmaple:
usb_cable: extcon-gpio-0 {
compatible = "extcon-gpio";
extcon-id = <1>; /* EXTCON_USB */
extcon-gpio = <&gpio6 1 GPIO_ACTIVE_HIGH>;
}

ta_cable: extcon-gpio-1 {
compatible = "extcon-gpio";
extcon-id = <3>; /* EXTCON_TA */
extcon-gpio = <&gpio3 2 GPIO_ACTIVE_LOW>;
debounce-ms = <50>; /* 50 millisecond */
wakeup-source;
}

&dwc3_usb {
extcon = <&usb_cable>;
};

&charger {
extcon = <&ta_cable>;
};

Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
---
.../devicetree/bindings/extcon/extcon-gpio.txt | 35 +++++++
drivers/extcon/extcon-gpio.c | 108 ++++++++++++++++-----
include/linux/extcon/extcon-gpio.h | 6 +-
3 files changed, 124 insertions(+), 25 deletions(-)
create mode 100644 Documentation/devicetree/bindings/extcon/extcon-gpio.txt

diff --git a/Documentation/devicetree/bindings/extcon/extcon-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt
new file mode 100644
index 000000000000..dc99a1d99b63
--- /dev/null
+++ b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt
@@ -0,0 +1,35 @@
+GPIO Extcon device
+
+Required properties:
+- compatible: Must be "extcon-gpio".
+- extcon-id: unique id for specific external connector.
+ See include/linux/extcon.h.
+- extcon-gpio: GPIO pin to detect the external connector. See gpio binding.
+
+Optional properties:
+- debounce-ms: the debounce dealy for GPIO pin in millisecond.
+- wakeup-source: Boolean, extcon can wake-up the system.
+
+Example: Examples of extcon-gpio node as listed below:
+
+ usb_cable: extcon-gpio-0 {
+ compatible = "extcon-gpio";
+ extcon-id = <1>; /* EXTCON_USB */
+ extcon-gpio = <&gpio6 1 GPIO_ACTIVE_HIGH>;
+ }
+
+ ta_cable: extcon-gpio-1 {
+ compatible = "extcon-gpio";
+ extcon-id = <3>; /* EXTCON_TA */
+ extcon-gpio = <&gpio3 2 GPIO_ACTIVE_LOW>;
+ debounce-ms = <50>; /* 50 millisecond */
+ wakeup-source;
+ }
+
+ &dwc3_usb {
+ extcon = <&usb_cable>;
+ };
+
+ &charger {
+ extcon = <&ta_cable>;
+ };
diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c
index 279ff8f6637d..611eb69392bb 100644
--- a/drivers/extcon/extcon-gpio.c
+++ b/drivers/extcon/extcon-gpio.c
@@ -1,8 +1,8 @@
/*
* extcon_gpio.c - Single-state GPIO extcon driver based on extcon class
*
- * Copyright (C) 2008 Google, Inc.
- * Author: Mike Lockwood <lockwood@xxxxxxxxxxx>
+ * Copyright (C) 2015 Chanwoo Choi <cw00.choi@xxxxxxxxxxx>, Samsung Electronics
+ * Copyright (C) 2008 Mike Lockwood <lockwood@xxxxxxxxxxx>, Google, Inc.
*
* Modified by MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx> to support extcon
* (originally switch class is supported)
@@ -26,12 +26,14 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/property.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

struct gpio_extcon_data {
struct extcon_dev *edev;
int irq;
+ bool irq_wakeup;
struct delayed_work work;
unsigned long debounce_jiffies;

@@ -61,19 +63,50 @@ static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}

-static int gpio_extcon_init(struct device *dev, struct gpio_extcon_data *data)
+static int gpio_extcon_parse_of(struct device *dev,
+ struct gpio_extcon_data *data)
{
- struct gpio_extcon_pdata *pdata = data->pdata;
+ struct gpio_extcon_pdata *pdata;
int ret;

- ret = devm_gpio_request_one(dev, pdata->gpio, GPIOF_DIR_IN,
- dev_name(dev));
+ pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ ret = device_property_read_u32(dev, "extcon-id", &pdata->extcon_id);
+ if (ret < 0)
+ return -EINVAL;
+
+ data->id_gpiod = devm_gpiod_get(dev, "extcon", GPIOD_IN);
if (ret < 0)
return ret;

- data->id_gpiod = gpio_to_desc(pdata->gpio);
- if (!data->id_gpiod)
- return -EINVAL;
+ data->irq_wakeup = device_property_read_bool(dev, "wakeup-source");
+
+ device_property_read_u32(dev, "debounce-ms", &pdata->debounce);
+
+ pdata->irq_flags = (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING
+ | IRQF_ONESHOT);
+
+ data->pdata = pdata;
+ return 0;
+}
+
+static int gpio_extcon_init(struct device *dev, struct gpio_extcon_data *data)
+{
+ struct gpio_extcon_pdata *pdata = data->pdata;
+ int ret;
+
+ if (!data->id_gpiod) {
+ ret = devm_gpio_request_one(dev, pdata->gpio, GPIOF_DIR_IN,
+ dev_name(dev));
+ if (ret < 0)
+ return ret;
+
+ data->id_gpiod = gpio_to_desc(pdata->gpio);
+ if (!data->id_gpiod)
+ return -EINVAL;
+ }

if (pdata->debounce) {
ret = gpiod_set_debounce(data->id_gpiod,
@@ -96,16 +129,20 @@ static int gpio_extcon_probe(struct platform_device *pdev)
struct gpio_extcon_data *data;
int ret;

- if (!pdata)
- return -EBUSY;
- if (!pdata->irq_flags || pdata->extcon_id > EXTCON_NONE)
- return -EINVAL;
-
- data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
- GFP_KERNEL);
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
- data->pdata = pdata;
+
+ if (!pdata) {
+ ret = gpio_extcon_parse_of(&pdev->dev, data);
+ if (ret < 0)
+ return ret;
+ } else {
+ data->pdata = pdata;
+ }
+
+ if (!data->pdata->irq_flags || data->pdata->extcon_id == EXTCON_NONE)
+ return -EINVAL;

/* Initialize the gpio */
ret = gpio_extcon_init(&pdev->dev, data);
@@ -113,7 +150,8 @@ static int gpio_extcon_probe(struct platform_device *pdev)
return ret;

/* Allocate the memory of extcon devie and register extcon device */
- data->edev = devm_extcon_dev_allocate(&pdev->dev, &pdata->extcon_id);
+ data->edev = devm_extcon_dev_allocate(&pdev->dev,
+ &data->pdata->extcon_id);
if (IS_ERR(data->edev)) {
dev_err(&pdev->dev, "failed to allocate extcon device\n");
return -ENOMEM;
@@ -130,7 +168,8 @@ static int gpio_extcon_probe(struct platform_device *pdev)
* is attached or detached.
*/
ret = devm_request_any_context_irq(&pdev->dev, data->irq,
- gpio_irq_handler, pdata->irq_flags,
+ gpio_irq_handler,
+ data->pdata->irq_flags,
pdev->name, data);
if (ret < 0)
return ret;
@@ -139,6 +178,8 @@ static int gpio_extcon_probe(struct platform_device *pdev)
/* Perform initial detection */
gpio_extcon_work(&data->work.work);

+ device_init_wakeup(&pdev->dev, data->irq_wakeup);
+
return 0;
}

@@ -152,11 +193,23 @@ static int gpio_extcon_remove(struct platform_device *pdev)
}

#ifdef CONFIG_PM_SLEEP
+static int gpio_extcon_suspend(struct device *dev)
+{
+ struct gpio_extcon_data *data = dev_get_drvdata(dev);
+
+ if (data->irq_wakeup)
+ enable_irq_wake(data->irq);
+
+ return 0;
+}
+
static int gpio_extcon_resume(struct device *dev)
{
- struct gpio_extcon_data *data;
+ struct gpio_extcon_data *data = dev_get_drvdata(dev);
+
+ if (data->irq_wakeup)
+ disable_irq_wake(data->irq);

- data = dev_get_drvdata(dev);
if (data->pdata->check_on_resume)
queue_delayed_work(system_power_efficient_wq,
&data->work, data->debounce_jiffies);
@@ -165,7 +218,16 @@ static int gpio_extcon_resume(struct device *dev)
}
#endif

-static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
+#if defined(CONFIG_OF)
+static const struct of_device_id gpio_extcon_of_match[] = {
+ { .compatible = "extcon-gpio", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, gpio_extcon_of_match);
+#endif
+
+static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops,
+ gpio_extcon_suspend, gpio_extcon_resume);

static struct platform_driver gpio_extcon_driver = {
.probe = gpio_extcon_probe,
@@ -173,11 +235,13 @@ static struct platform_driver gpio_extcon_driver = {
.driver = {
.name = "extcon-gpio",
.pm = &gpio_extcon_pm_ops,
+ .of_match_table = gpio_extcon_of_match,
},
};

module_platform_driver(gpio_extcon_driver);

+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@xxxxxxxxxxx>");
MODULE_AUTHOR("Mike Lockwood <lockwood@xxxxxxxxxxx>");
MODULE_DESCRIPTION("GPIO extcon driver");
MODULE_LICENSE("GPL");
diff --git a/include/linux/extcon/extcon-gpio.h b/include/linux/extcon/extcon-gpio.h
index 7cacafb78b09..bcc6d7f7116a 100644
--- a/include/linux/extcon/extcon-gpio.h
+++ b/include/linux/extcon/extcon-gpio.h
@@ -1,8 +1,8 @@
/*
* Single-state GPIO extcon driver based on extcon class
*
- * Copyright (C) 2012 Samsung Electronics
- * Author: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
+ * Copyright (C) 2015 Chanwoo Choi <cw00.choi@xxxxxxxxxxx>, Samsung Electronics
+ * Copyright (C) 2012 MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>, Samsung Electronics
*
* based on switch class driver
* Copyright (C) 2008 Google, Inc.
@@ -38,7 +38,7 @@ struct gpio_extcon_pdata {
unsigned int extcon_id;
unsigned gpio;
bool gpio_active_low;
- unsigned long debounce;
+ unsigned int debounce;
unsigned long irq_flags;

bool check_on_resume;
--
1.8.0

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Next message: Alexander Kapshuk: "Re: [PATCH] ver_linux: libcpp.patch"
Previous message: Meelis Roos: "Re: bisected: Re: 4.3.0-rc3-00042: ACPI Warning: AcpiEnable failed"
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