power: supply: gpio_charger: switch to using GPIO descriptors

The GPIO charger is using a mix of the legacy GPIO interface
and <linux/of_gpio.h> which is not the modern way to use GPIOs.

Refactor like this:

- Use a GPIO descriptor for the GPIO line used to monitor the
  charger.
- Fetch the descriptor with devm_gpiod_get() as the first
  method.
- If this fails and we are *not* using device tree, then
  start looking to see if we can use platform data instead.
- After looking up and requesting a GPIO number with the
  legacy API, convert it to a descriptor.

This way we can later isolate and drop the legacy code as
more platforms move over to using descriptors.

Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c
index c5869b1941acddbe75a1221527238d6641d6daf3..001731e88718e38cd31a0314a6e3409dad722684 100644 (file)
--- a/drivers/power/supply/gpio-charger.c
+++ b/drivers/power/supply/gpio-charger.c
@@ -14,7 +14,7 @@
  */
 
 #include <linux/device.h>
-#include <linux/gpio.h>
+#include <linux/gpio.h> /* For legacy platform data */
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
@@ -23,7 +23,7 @@
 #include <linux/power_supply.h>
 #include <linux/slab.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
 
 #include <linux/power/gpio-charger.h>
 
@@ -34,6 +34,8 @@ struct gpio_charger {
 
        struct power_supply *charger;
        struct power_supply_desc charger_desc;
+       struct gpio_desc *gpiod;
+       bool legacy_gpio_requested;
 };
 
 static irqreturn_t gpio_charger_irq(int irq, void *devid)
@@ -58,7 +60,8 @@ static int gpio_charger_get_property(struct power_supply *psy,
 
        switch (psp) {
        case POWER_SUPPLY_PROP_ONLINE:
-               val->intval = !!gpio_get_value_cansleep(pdata->gpio);
+               val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
+               /* This xor is only ever used with legacy pdata GPIO */
                val->intval ^= pdata->gpio_active_low;
                break;
        default:
@@ -78,7 +81,6 @@ struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
        struct device_node *np = dev->of_node;
        struct gpio_charger_platform_data *pdata;
        const char *chargetype;
-       enum of_gpio_flags flags;
        int ret;
 
        if (!np)
@@ -89,16 +91,6 @@ struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
                return ERR_PTR(-ENOMEM);
 
        pdata->name = np->name;
-
-       pdata->gpio = of_get_gpio_flags(np, 0, &flags);
-       if (pdata->gpio < 0) {
-               if (pdata->gpio != -EPROBE_DEFER)
-                       dev_err(dev, "could not get charger gpio\n");
-               return ERR_PTR(pdata->gpio);
-       }
-
-       pdata->gpio_active_low = !!(flags & OF_GPIO_ACTIVE_LOW);
-
        pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
        ret = of_property_read_string(np, "charger-type", &chargetype);
        if (ret >= 0) {
@@ -144,11 +136,6 @@ static int gpio_charger_probe(struct platform_device *pdev)
                }
        }
 
-       if (!gpio_is_valid(pdata->gpio)) {
-               dev_err(&pdev->dev, "Invalid gpio pin\n");
-               return -EINVAL;
-       }
-
        gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
                                        GFP_KERNEL);
        if (!gpio_charger) {
@@ -156,6 +143,45 @@ static int gpio_charger_probe(struct platform_device *pdev)
                return -ENOMEM;
        }
 
+       /*
+        * This will fetch a GPIO descriptor from device tree, ACPI or
+        * boardfile descriptor tables. It's good to try this first.
+        */
+       gpio_charger->gpiod = devm_gpiod_get(&pdev->dev, NULL, GPIOD_IN);
+
+       /*
+        * If this fails and we're not using device tree, try the
+        * legacy platform data method.
+        */
+       if (IS_ERR(gpio_charger->gpiod) && !pdev->dev.of_node) {
+               /* Non-DT: use legacy GPIO numbers */
+               if (!gpio_is_valid(pdata->gpio)) {
+                       dev_err(&pdev->dev, "Invalid gpio pin in pdata\n");
+                       return -EINVAL;
+               }
+               ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
+               if (ret) {
+                       dev_err(&pdev->dev, "Failed to request gpio pin: %d\n",
+                               ret);
+                       return ret;
+               }
+               gpio_charger->legacy_gpio_requested = true;
+               ret = gpio_direction_input(pdata->gpio);
+               if (ret) {
+                       dev_err(&pdev->dev, "Failed to set gpio to input: %d\n",
+                               ret);
+                       goto err_gpio_free;
+               }
+               /* Then convert this to gpiod for now */
+               gpio_charger->gpiod = gpio_to_desc(pdata->gpio);
+       } else if (IS_ERR(gpio_charger->gpiod)) {
+               /* Just try again if this happens */
+               if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER)
+                       return -EPROBE_DEFER;
+               dev_err(&pdev->dev, "error getting GPIO descriptor\n");
+               return PTR_ERR(gpio_charger->gpiod);
+       }
+
        charger_desc = &gpio_charger->charger_desc;
 
        charger_desc->name = pdata->name ? pdata->name : "gpio-charger";
@@ -169,17 +195,6 @@ static int gpio_charger_probe(struct platform_device *pdev)
        psy_cfg.of_node = pdev->dev.of_node;
        psy_cfg.drv_data = gpio_charger;
 
-       ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
-       if (ret) {
-               dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
-               goto err_free;
-       }
-       ret = gpio_direction_input(pdata->gpio);
-       if (ret) {
-               dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
-               goto err_gpio_free;
-       }
-
        gpio_charger->pdata = pdata;
 
        gpio_charger->charger = power_supply_register(&pdev->dev,
@@ -191,7 +206,7 @@ static int gpio_charger_probe(struct platform_device *pdev)
                goto err_gpio_free;
        }
 
-       irq = gpio_to_irq(pdata->gpio);
+       irq = gpiod_to_irq(gpio_charger->gpiod);
        if (irq > 0) {
                ret = request_any_context_irq(irq, gpio_charger_irq,
                                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
@@ -209,8 +224,8 @@ static int gpio_charger_probe(struct platform_device *pdev)
        return 0;
 
 err_gpio_free:
-       gpio_free(pdata->gpio);
-err_free:
+       if (gpio_charger->legacy_gpio_requested)
+               gpio_free(pdata->gpio);
        return ret;
 }
 
@@ -223,7 +238,8 @@ static int gpio_charger_remove(struct platform_device *pdev)
 
        power_supply_unregister(gpio_charger->charger);
 
-       gpio_free(gpio_charger->pdata->gpio);
+       if (gpio_charger->legacy_gpio_requested)
+               gpio_free(gpio_charger->pdata->gpio);
 
        return 0;
 }