sh-pfc: Add DT support

Support device instantiation through the device tree. The compatible
property is used to select the SoC pinmux information.

Set the gpio_chip device field to the PFC device to enable automatic
GPIO OF support.

Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 116 insertions, 0 deletions

diff --git a/drivers/pinctrl/sh-pfc/pinctrl.c b/drivers/pinctrl/sh-pfc/pinctrl.c
index 3492ec9a33b7..7e32bb8c08dd 100644
--- a/drivers/pinctrl/sh-pfc/pinctrl.c
+++ b/drivers/pinctrl/sh-pfc/pinctrl.c
@@ -14,7 +14,9 @@
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/machine.h>
 #include <linux/pinctrl/pinconf.h>
 #include <linux/pinctrl/pinconf-generic.h>
 #include <linux/pinctrl/pinctrl.h>
@@ -72,11 +74,125 @@ static void sh_pfc_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
         seq_printf(s, "%s", DRV_NAME);
 }
 
+static int sh_pfc_dt_subnode_to_map(struct device *dev, struct device_node *np,
+                                    struct pinctrl_map **map,
+                                    unsigned int *num_maps, unsigned int *index)
+{
+        struct pinctrl_map *maps = *map;
+        unsigned int nmaps = *num_maps;
+        unsigned int idx = *index;
+        const char *function = NULL;
+        struct property *prop;
+        const char *group;
+        int ret;
+
+        /* Parse the function and configuration properties. At least a function
+         * or one configuration must be specified.
+         */
+        ret = of_property_read_string(np, "renesas,function", &function);
+        if (ret < 0 && ret != -EINVAL) {
+                dev_err(dev, "Invalid function in DT\n");
+                return ret;
+        }
+
+        if (!function) {
+                dev_err(dev, "DT node must contain at least one function\n");
+                goto done;
+        }
+
+        /* Count the number of groups and reallocate mappings. */
+        ret = of_property_count_strings(np, "renesas,groups");
+        if (ret < 0 && ret != -EINVAL) {
+                dev_err(dev, "Invalid pin groups list in DT\n");
+                goto done;
+        }
+
+        if (!ret) {
+                dev_err(dev, "No group provided in DT node\n");
+                ret = -ENODEV;
+                goto done;
+        }
+
+        nmaps += ret;
+
+        maps = krealloc(maps, sizeof(*maps) * nmaps, GFP_KERNEL);
+        if (maps == NULL) {
+                ret = -ENOMEM;
+                goto done;
+        }
+
+        *map = maps;
+        *num_maps = nmaps;
+
+        /* Iterate over pins and groups and create the mappings. */
+        of_property_for_each_string(np, "renesas,groups", prop, group) {
+                maps[idx].type = PIN_MAP_TYPE_MUX_GROUP;
+                maps[idx].data.mux.group = group;
+                maps[idx].data.mux.function = function;
+                idx++;
+        }
+
+        ret = 0;
+
+done:
+        *index = idx;
+        return ret;
+}
+
+static void sh_pfc_dt_free_map(struct pinctrl_dev *pctldev,
+                               struct pinctrl_map *map, unsigned num_maps)
+{
+        kfree(map);
+}
+
+static int sh_pfc_dt_node_to_map(struct pinctrl_dev *pctldev,
+                                 struct device_node *np,
+                                 struct pinctrl_map **map, unsigned *num_maps)
+{
+        struct sh_pfc_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+        struct device *dev = pmx->pfc->dev;
+        struct device_node *child;
+        unsigned int index;
+        int ret;
+
+        *map = NULL;
+        *num_maps = 0;
+        index = 0;
+
+        for_each_child_of_node(np, child) {
+                ret = sh_pfc_dt_subnode_to_map(dev, child, map, num_maps,
+                                               &index);
+                if (ret < 0)
+                        goto done;
+        }
+
+        /* If no mapping has been found in child nodes try the config node. */
+        if (*num_maps == 0) {
+                ret = sh_pfc_dt_subnode_to_map(dev, np, map, num_maps, &index);
+                if (ret < 0)
+                        goto done;
+        }
+
+        if (*num_maps)
+                return 0;
+
+        dev_err(dev, "no mapping found in node %s\n", np->full_name);
+        ret = -EINVAL;
+
+done:
+        if (ret < 0)
+                sh_pfc_dt_free_map(pctldev, *map, *num_maps);
+
+        return ret;
+}
+
 static const struct pinctrl_ops sh_pfc_pinctrl_ops = {
         .get_groups_count       = sh_pfc_get_groups_count,
         .get_group_name         = sh_pfc_get_group_name,
         .get_group_pins         = sh_pfc_get_group_pins,
         .pin_dbg_show           = sh_pfc_pin_dbg_show,
+        .dt_node_to_map         = sh_pfc_dt_node_to_map,
+        .dt_free_map            = sh_pfc_dt_free_map,
 };
 
 static int sh_pfc_get_functions_count(struct pinctrl_dev *pctldev)