gpio: em: Add pinctrl support

Register the GPIO pin range, and request and free GPIO pins using the
pinctrl API. The pctl_name platform data member should be used by
platform devices to point out which pinctrl device to use.

Follows same style as "dc3465a gpio-rcar: Add pinctrl support",
by Laurent Pinchart, thanks to him.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

2 files changed, 26 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-em.c b/drivers/gpio/gpio-em.c
index 5cba855638bf..eca119b58c21 100644
--- a/drivers/gpio/gpio-em.c
+++ b/drivers/gpio/gpio-em.c
@@ -30,6 +30,7 @@
 #include <linux/gpio.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_data/gpio-em.h>
 
 struct em_gio_priv {
@@ -216,6 +217,21 @@ static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
         return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
 }
 
+static int em_gio_request(struct gpio_chip *chip, unsigned offset)
+{
+        return pinctrl_request_gpio(chip->base + offset);
+}
+
+static void em_gio_free(struct gpio_chip *chip, unsigned offset)
+{
+        pinctrl_free_gpio(chip->base + offset);
+
+        /* Set the GPIO as an input to ensure that the next GPIO request won't
+        * drive the GPIO pin as an output.
+        */
+        em_gio_direction_input(chip, offset);
+}
+
 static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int virq,
                                  irq_hw_number_t hw)
 {
@@ -308,6 +324,8 @@ static int em_gio_probe(struct platform_device *pdev)
         gpio_chip->direction_output = em_gio_direction_output;
         gpio_chip->set = em_gio_set;
         gpio_chip->to_irq = em_gio_to_irq;
+        gpio_chip->request = em_gio_request;
+        gpio_chip->free = em_gio_free;
         gpio_chip->label = name;
         gpio_chip->owner = THIS_MODULE;
         gpio_chip->base = pdata->gpio_base;
@@ -351,6 +369,13 @@ static int em_gio_probe(struct platform_device *pdev)
                 dev_err(&pdev->dev, "failed to add GPIO controller\n");
                 goto err1;
         }
+
+        if (pdata->pctl_name) {
+                ret = gpiochip_add_pin_range(gpio_chip, pdata->pctl_name, 0,
+                                             gpio_chip->base, gpio_chip->ngpio);
+                if (ret < 0)
+                        dev_warn(&pdev->dev, "failed to add pin range\n");
+        }
         return 0;
 
 err1:
diff --git a/include/linux/platform_data/gpio-em.h b/include/linux/platform_data/gpio-em.h
index 573edfb046c4..7c5a519d2dcd 100644
--- a/include/linux/platform_data/gpio-em.h
+++ b/include/linux/platform_data/gpio-em.h
@@ -5,6 +5,7 @@ struct gpio_em_config {
         unsigned int gpio_base;
         unsigned int irq_base;
         unsigned int number_of_pins;
+        const char *pctl_name;
 };
 
 #endif /* __GPIO_EM_H__ */