pinctrl: add pin list based GPIO ranges

Traditionally, GPIO ranges are based on consecutive ranges of both GPIO
and pin numbers. This patch allows for GPIO ranges with arbitrary lists
of pin numbers.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index dca9208f54633dc404956a74a1afd39fe7f09e85..33710b5e7bb5b47f134401cfaec7ca333bab85f5 100644 (file)
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -282,6 +282,29 @@ static int pinctrl_register_pins(struct pinctrl_dev *pctldev,
        return 0;
 }
 
+/**
+ * gpio_to_pin() - GPIO range GPIO number to pin number translation
+ * @range: GPIO range used for the translation
+ * @gpio: gpio pin to translate to a pin number
+ *
+ * Finds the pin number for a given GPIO using the specified GPIO range
+ * as a base for translation. The distinction between linear GPIO ranges
+ * and pin list based GPIO ranges is managed correctly by this function.
+ *
+ * This function assumes the gpio is part of the specified GPIO range, use
+ * only after making sure this is the case (e.g. by calling it on the
+ * result of successful pinctrl_get_device_gpio_range calls)!
+ */
+static inline int gpio_to_pin(struct pinctrl_gpio_range *range,
+                               unsigned int gpio)
+{
+       unsigned int offset = gpio - range->base;
+       if (range->pins)
+               return range->pins[offset];
+       else
+               return range->pin_base + offset;
+}
+
 /**
  * pinctrl_match_gpio_range() - check if a certain GPIO pin is in range
  * @pctldev: pin controller device to check
@@ -448,8 +471,14 @@ pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev,
        /* Loop over the ranges */
        list_for_each_entry(range, &pctldev->gpio_ranges, node) {
                /* Check if we're in the valid range */
-               if (pin >= range->pin_base &&
-                   pin < range->pin_base + range->npins) {
+               if (range->pins) {
+                       int a;
+                       for (a = 0; a < range->npins; a++) {
+                               if (range->pins[a] == pin)
+                                       return range;
+                       }
+               } else if (pin >= range->pin_base &&
+                          pin < range->pin_base + range->npins) {
                        mutex_unlock(&pctldev->mutex);
                        return range;
                }
@@ -529,7 +558,7 @@ int pinctrl_request_gpio(unsigned gpio)
        }
 
        /* Convert to the pin controllers number space */
-       pin = gpio - range->base + range->pin_base;
+       pin = gpio_to_pin(range, gpio);
 
        ret = pinmux_request_gpio(pctldev, range, pin, gpio);
 
@@ -559,7 +588,7 @@ void pinctrl_free_gpio(unsigned gpio)
        mutex_lock(&pctldev->mutex);
 
        /* Convert to the pin controllers number space */
-       pin = gpio - range->base + range->pin_base;
+       pin = gpio_to_pin(range, gpio);
 
        pinmux_free_gpio(pctldev, pin, range);
 
@@ -582,7 +611,7 @@ static int pinctrl_gpio_direction(unsigned gpio, bool input)
        mutex_lock(&pctldev->mutex);
 
        /* Convert to the pin controllers number space */
-       pin = gpio - range->base + range->pin_base;
+       pin = gpio_to_pin(range, gpio);
        ret = pinmux_gpio_direction(pctldev, range, pin, input);
 
        mutex_unlock(&pctldev->mutex);
@@ -1349,11 +1378,21 @@ static int pinctrl_gpioranges_show(struct seq_file *s, void *what)
 
        /* Loop over the ranges */
        list_for_each_entry(range, &pctldev->gpio_ranges, node) {
-               seq_printf(s, "%u: %s GPIOS [%u - %u] PINS [%u - %u]\n",
-                          range->id, range->name,
-                          range->base, (range->base + range->npins - 1),
-                          range->pin_base,
-                          (range->pin_base + range->npins - 1));
+               if (range->pins) {
+                       int a;
+                       seq_printf(s, "%u: %s GPIOS [%u - %u] PINS {",
+                               range->id, range->name,
+                               range->base, (range->base + range->npins - 1));
+                       for (a = 0; a < range->npins - 1; a++)
+                               seq_printf(s, "%u, ", range->pins[a]);
+                       seq_printf(s, "%u}\n", range->pins[a]);
+               }
+               else
+                       seq_printf(s, "%u: %s GPIOS [%u - %u] PINS [%u - %u]\n",
+                               range->id, range->name,
+                               range->base, (range->base + range->npins - 1),
+                               range->pin_base,
+                               (range->pin_base + range->npins - 1));
        }
 
        mutex_unlock(&pctldev->mutex);

diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
index 2c2a9e8d8578310e453776e6668e9b6a915ac2c2..176a6c1b4e03b9683b0d12c84490df1baa375b56 100644 (file)
--- a/include/linux/pinctrl/pinctrl.h
+++ b/include/linux/pinctrl/pinctrl.h
@@ -49,7 +49,8 @@ struct pinctrl_pin_desc {
  * @name: a name for the chip in this range
  * @id: an ID number for the chip in this range
  * @base: base offset of the GPIO range
- * @pin_base: base pin number of the GPIO range
+ * @pin_base: base pin number of the GPIO range if pins != NULL
+ * @pins: enumeration of pins in GPIO range or NULL
  * @npins: number of pins in the GPIO range, including the base number
  * @gc: an optional pointer to a gpio_chip
  */
@@ -59,6 +60,7 @@ struct pinctrl_gpio_range {
        unsigned int id;
        unsigned int base;
        unsigned int pin_base;
+       unsigned const *pins;
        unsigned int npins;
        struct gpio_chip *gc;
 };