[PATCH 1/2] extcon: gpio: add device tree support for extcon-gpio

[Venkat Reddy Talla]

Adding device tree support for extcon-gpio driver.

Signed-off-by: Venkat Reddy Talla <vreddyta...@nvidia.com>
---
 drivers/extcon/extcon-gpio.c       | 80 +++++++++++++++++++++++++++++++++++---
 include/linux/extcon/extcon-gpio.h |  2 +
 2 files changed, 76 insertions(+), 6 deletions(-)

diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c
index d023789..b7fae7e 100644
--- a/drivers/extcon/extcon-gpio.c
+++ b/drivers/extcon/extcon-gpio.c
@@ -28,6 +28,8 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 
 struct gpio_extcon_data {
        struct extcon_dev *edev;
@@ -90,21 +92,79 @@ static int gpio_extcon_init(struct device *dev, struct 
gpio_extcon_data *data)
        return 0;
 }
 
+static struct gpio_extcon_pdata *gpio_extcon_of_pdata(
+               struct platform_device *pdev)
+{
+       struct gpio_extcon_pdata *pdata;
+       struct device_node *np = pdev->dev.of_node;
+       int gpio;
+       u32 pval;
+       int ret;
+
+       pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+       if (!pdata)
+               return ERR_PTR(-ENOMEM);
+
+       gpio = of_get_named_gpio(np, "gpio", 0);
+       if (gpio < 0)
+               return ERR_PTR(gpio);
+
+       pdata->gpio = gpio;
+
+       ret = of_property_read_u32(np, "extcon-gpio,irq-flags", &pval);
+       if (!ret)
+               pdata->irq_flags = pval;
+       else
+               pdata->irq_flags = IRQF_TRIGGER_RISING |
+                                               IRQF_TRIGGER_FALLING;
+
+       ret = of_property_read_u32(np, "extcon-gpio,debounce", &pval);
+       if (!ret)
+               pdata->debounce = pval;
+
+       pdata->gpio_active_low = of_property_read_bool(np,
+                               "extcon-gpio,connection-state-low");
+
+       pdata->extcon_cable_cnt = of_property_count_u32_elems(np,
+                                               "extcon-gpio,cable-names");
+       if (pdata->extcon_cable_cnt <= 0) {
+               dev_err(&pdev->dev, "not found out cable names\n");
+               return ERR_PTR(-EINVAL);
+       }
+
+       pdata->extcon_cable_names = devm_kzalloc(&pdev->dev,
+                       (pdata->extcon_cable_cnt) *
+                       sizeof(*pdata->extcon_cable_names), GFP_KERNEL);
+       if (!pdata->extcon_cable_names)
+               return ERR_PTR(-ENOMEM);
+
+       ret = of_property_read_u32_array(np, "extcon-gpio,cable-names",
+                       pdata->extcon_cable_names, pdata->extcon_cable_cnt);
+       if (ret)
+               return ERR_PTR(-EINVAL);
+
+       return pdata;
+}
+
 static int gpio_extcon_probe(struct platform_device *pdev)
 {
        struct gpio_extcon_pdata *pdata = dev_get_platdata(&pdev->dev);
        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);
        if (!data)
                return -ENOMEM;
+
+       if (!pdata && pdev->dev.of_node)
+               pdata = gpio_extcon_of_pdata(pdev);
+
+       if (IS_ERR(pdata))
+               return PTR_ERR(pdata);
+       if (!pdata->irq_flags || !pdata->extcon_cable_names)
+               return -EINVAL;
+
        data->pdata = pdata;
 
        /* Initialize the gpio */
@@ -113,7 +173,8 @@ 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,
+                               pdata->extcon_cable_names);
        if (IS_ERR(data->edev)) {
                dev_err(&pdev->dev, "failed to allocate extcon device\n");
                return -ENOMEM;
@@ -167,12 +228,19 @@ static int gpio_extcon_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
 
+static const struct of_device_id of_extcon_gpio_tbl[] = {
+       { .compatible = "extcon-gpio", },
+       { /* end */ }
+};
+MODULE_DEVICE_TABLE(of, of_extcon_gpio_tbl);
+
 static struct platform_driver gpio_extcon_driver = {
        .probe          = gpio_extcon_probe,
        .remove         = gpio_extcon_remove,
        .driver         = {
                .name   = "extcon-gpio",
                .pm     = &gpio_extcon_pm_ops,
+               .of_match_table = of_extcon_gpio_tbl,
        },
 };
 
diff --git a/include/linux/extcon/extcon-gpio.h 
b/include/linux/extcon/extcon-gpio.h
index 7cacafb..c27df9b 100644
--- a/include/linux/extcon/extcon-gpio.h
+++ b/include/linux/extcon/extcon-gpio.h
@@ -36,6 +36,8 @@
  */
 struct gpio_extcon_pdata {
        unsigned int extcon_id;
+       unsigned int *extcon_cable_names;
+       int extcon_cable_cnt;
        unsigned gpio;
        bool gpio_active_low;
        unsigned long debounce;
-- 
2.1.4