pinctrl/gpio: non-linear GPIO ranges accesible from gpiolib

This patch adds the infrastructure required to register non-linear gpio
ranges through gpiolib and the standard GPIO device tree bindings.

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

diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index 6cec6ff20d2e576ff51010389bcb494c4d2cd225..0c85bb6e3a80282edce785cad57468c6e11cfae0 100644 (file)
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -87,8 +87,10 @@ controllers. The gpio-ranges property described below represents this, and
 contains information structures as follows:
 
        gpio-range-list ::= <single-gpio-range> [gpio-range-list]
-       single-gpio-range ::=
+       single-gpio-range ::= <numeric-gpio-range> | <named-gpio-range>
+       numeric-gpio-range ::=
                        <pinctrl-phandle> <gpio-base> <pinctrl-base> <count>
+       named-gpio-range ::= <pinctrl-phandle> <gpio-base> '<0 0>'
        gpio-phandle : phandle to pin controller node.
        gpio-base : Base GPIO ID in the GPIO controller
        pinctrl-base : Base pinctrl pin ID in the pin controller
@@ -97,6 +99,19 @@ contains information structures as follows:
 The "pin controller node" mentioned above must conform to the bindings
 described in ../pinctrl/pinctrl-bindings.txt.
 
+In case named gpio ranges are used (ranges with both <pinctrl-base> and
+<count> set to 0), the property gpio-ranges-group-names contains one string
+for every single-gpio-range in gpio-ranges:
+       gpiorange-names-list ::= <gpiorange-name> [gpiorange-names-list]
+       gpiorange-name : Name of the pingroup associated to the GPIO range in
+                       the respective pin controller.
+
+Elements of gpiorange-names-list corresponding to numeric ranges contain
+the empty string. Elements of gpiorange-names-list corresponding to named
+ranges contain the name of a pin group defined in the respective pin
+controller. The number of pins/GPIOs in the range is the number of pins in
+that pin group.
+
 Previous versions of this binding required all pin controller nodes that
 were referenced by any gpio-ranges property to contain a property named
 #gpio-range-cells with value <3>. This requirement is now deprecated.
@@ -104,7 +119,7 @@ However, that property may still exist in older device trees for
 compatibility reasons, and would still be required even in new device
 trees that need to be compatible with older software.
 
-Example:
+Example 1:
 
        qe_pio_e: gpio-controller@1460 {
                #gpio-cells = <2>;
@@ -117,3 +132,24 @@ Example:
 Here, a single GPIO controller has GPIOs 0..9 routed to pin controller
 pinctrl1's pins 20..29, and GPIOs 10..19 routed to pin controller pinctrl2's
 pins 50..59.
+
+Example 2:
+
+       gpio_pio_i: gpio-controller@14B0 {
+               #gpio-cells = <2>;
+               compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank";
+               reg = <0x1480 0x18>;
+               gpio-controller;
+               gpio-ranges =                   <&pinctrl1 0 20 10>,
+                                               <&pinctrl2 10 0 0>,
+                                               <&pinctrl1 15 0 10>,
+                                               <&pinctrl2 25 0 0>;
+               gpio-ranges-group-names =       "",
+                                               "foo",
+                                               "",
+                                               "bar";
+       };
+
+Here, three GPIO ranges are defined wrt. two pin controllers. pinctrl1 GPIO
+ranges are defined using pin numbers whereas the GPIO ranges wrt. pinctrl2
+are named "foo" and "bar".

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 0dfaf20e4dad4175fc7d5f49e6989d609876b123..e78760921bd72d9631ad89814f23fd15faf2331a 100644 (file)
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -190,10 +190,15 @@ static void of_gpiochip_add_pin_range(struct gpio_chip *chip)
        struct of_phandle_args pinspec;
        struct pinctrl_dev *pctldev;
        int index = 0, ret;
+       const char *name;
+       static const char group_names_propname[] = "gpio-ranges-group-names";
+       struct property *group_names;
 
        if (!np)
                return;
 
+       group_names = of_find_property(np, group_names_propname, NULL);
+
        for (;; index++) {
                ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
                                index, &pinspec);
@@ -204,14 +209,56 @@ static void of_gpiochip_add_pin_range(struct gpio_chip *chip)
                if (!pctldev)
                        break;
 
-               ret = gpiochip_add_pin_range(chip,
-                                            pinctrl_dev_get_devname(pctldev),
-                                            pinspec.args[0],
-                                            pinspec.args[1],
-                                            pinspec.args[2]);
-
-               if (ret)
-                       break;
+               if (pinspec.args[2]) {
+                       if (group_names) {
+                               ret = of_property_read_string_index(np,
+                                               group_names_propname,
+                                               index, &name);
+                               if (strlen(name)) {
+                                       pr_err("%s: Group name of numeric GPIO ranges must be the empty string.\n",
+                                               np->full_name);
+                                       break;
+                               }
+                       }
+                       /* npins != 0: linear range */
+                       ret = gpiochip_add_pin_range(chip,
+                                       pinctrl_dev_get_devname(pctldev),
+                                       pinspec.args[0],
+                                       pinspec.args[1],
+                                       pinspec.args[2]);
+                       if (ret)
+                               break;
+               } else {
+                       /* npins == 0: special range */
+                       if (pinspec.args[1]) {
+                               pr_err("%s: Illegal gpio-range format.\n",
+                                       np->full_name);
+                               break;
+                       }
+
+                       if (!group_names) {
+                               pr_err("%s: GPIO group range requested but no %s property.\n",
+                                       np->full_name, group_names_propname);
+                               break;
+                       }
+
+                       ret = of_property_read_string_index(np,
+                                               group_names_propname,
+                                               index, &name);
+                       if (ret)
+                               break;
+
+                       if (!strlen(name)) {
+                               pr_err("%s: Group name of GPIO group range cannot be the empty string.\n",
+                               np->full_name);
+                               break;
+                       }
+
+                       ret = gpiochip_add_pingroup_range(chip, pctldev,
+                                               pinspec.args[0], name);
+                       if (ret)
+                               break;
+               }
        }
 }
 

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 86ef3461ec0647b42f1e1ff94a9f47225151f7f6..b83b7e491f760a1d549d420f872c1c35a2872df8 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1319,6 +1319,53 @@ EXPORT_SYMBOL_GPL(gpiochip_find);
 
 #ifdef CONFIG_PINCTRL
 
+/**
+ * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
+ * @chip: the gpiochip to add the range for
+ * @pinctrl: the dev_name() of the pin controller to map to
+ * @gpio_offset: the start offset in the current gpio_chip number space
+ * @pin_group: name of the pin group inside the pin controller
+ */
+int gpiochip_add_pingroup_range(struct gpio_chip *chip,
+                       struct pinctrl_dev *pctldev,
+                       unsigned int gpio_offset, const char *pin_group)
+{
+       struct gpio_pin_range *pin_range;
+       int ret;
+
+       pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
+       if (!pin_range) {
+               pr_err("%s: GPIO chip: failed to allocate pin ranges\n",
+                               chip->label);
+               return -ENOMEM;
+       }
+
+       /* Use local offset as range ID */
+       pin_range->range.id = gpio_offset;
+       pin_range->range.gc = chip;
+       pin_range->range.name = chip->label;
+       pin_range->range.base = chip->base + gpio_offset;
+       pin_range->pctldev = pctldev;
+
+       ret = pinctrl_get_group_pins(pctldev, pin_group,
+                                       &pin_range->range.pins,
+                                       &pin_range->range.npins);
+       if (ret < 0)
+               return ret;
+
+       pinctrl_add_gpio_range(pctldev, &pin_range->range);
+
+       pr_debug("GPIO chip %s: created GPIO range %d->%d ==> %s PINGRP %s\n",
+                chip->label, gpio_offset,
+                gpio_offset + pin_range->range.npins - 1,
+                pinctrl_dev_get_devname(pctldev), pin_group);
+
+       list_add_tail(&pin_range->node, &chip->pin_ranges);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
+
 /**
  * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
  * @chip: the gpiochip to add the range for

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 92f86ab30a1385993ccaaf4b17018f9dad26f9ad..5ee61a470016fa8f2753cf21fc2e6ff0966d8d78 100644 (file)
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -462,6 +462,20 @@ struct pinctrl_dev *pinctrl_find_and_add_gpio_range(const char *devname,
 }
 EXPORT_SYMBOL_GPL(pinctrl_find_and_add_gpio_range);
 
+int pinctrl_get_group_pins(struct pinctrl_dev *pctldev, const char *pin_group,
+                               const unsigned **pins, unsigned *num_pins)
+{
+       const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+       int gs;
+
+       gs = pinctrl_get_group_selector(pctldev, pin_group);
+       if (gs < 0)
+               return gs;
+
+       return pctlops->get_group_pins(pctldev, gs, pins, num_pins);
+}
+EXPORT_SYMBOL_GPL(pinctrl_get_group_pins);
+
 /**
  * pinctrl_find_gpio_range_from_pin() - locate the GPIO range for a pin
  * @pctldev: the pin controller device to look in

diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index bde646995d10ab7c214b69fd818ae8328aa6b319..523f4052553574082a256a239f3a573432e501e9 100644 (file)
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -228,6 +228,9 @@ struct gpio_pin_range {
 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
                           unsigned int gpio_offset, unsigned int pin_offset,
                           unsigned int npins);
+int gpiochip_add_pingroup_range(struct gpio_chip *chip,
+                       struct pinctrl_dev *pctldev,
+                       unsigned int gpio_offset, const char *pin_group);
 void gpiochip_remove_pin_ranges(struct gpio_chip *chip);
 
 #else
@@ -239,6 +242,13 @@ gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
 {
        return 0;
 }
+static inline int
+gpiochip_add_pingroup_range(struct gpio_chip *chip,
+                       struct pinctrl_dev *pctldev,
+                       unsigned int gpio_offset, const char *pin_group)
+{
+       return 0;
+}
 
 static inline void
 gpiochip_remove_pin_ranges(struct gpio_chip *chip)

diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 552e3f46e4a33f5b4915c86182c13cf0c876233a..b8d0e53a802f0eacadcd44f4f3fba8ec1163eda5 100644 (file)
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -80,6 +80,7 @@ static inline int irq_to_gpio(unsigned int irq)
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/bug.h>
+#include <linux/pinctrl/pinctrl.h>
 
 struct device;
 struct gpio_chip;
@@ -220,6 +221,15 @@ gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
        return -EINVAL;
 }
 
+static inline int
+gpiochip_add_pingroup_range(struct gpio_chip *chip,
+                       struct pinctrl_dev *pctldev,
+                       unsigned int gpio_offset, const char *pin_group)
+{
+       WARN_ON(1);
+       return -EINVAL;
+}
+
 static inline void
 gpiochip_remove_pin_ranges(struct gpio_chip *chip)
 {

diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
index 5979147d2bda99587e07cc52e1fc4f0f3fd771f0..fefb88663975a363f42d15d05d2787fe7cbea1d7 100644 (file)
--- a/include/linux/pinctrl/pinctrl.h
+++ b/include/linux/pinctrl/pinctrl.h
@@ -144,6 +144,9 @@ extern struct pinctrl_dev *pinctrl_find_and_add_gpio_range(const char *devname,
 extern struct pinctrl_gpio_range *
 pinctrl_find_gpio_range_from_pin(struct pinctrl_dev *pctldev,
                                 unsigned int pin);
+extern int pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
+                               const char *pin_group, const unsigned **pins,
+                               unsigned *num_pins);
 
 #ifdef CONFIG_OF
 extern struct pinctrl_dev *of_pinctrl_get(struct device_node *np);