pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c

This change separates two aspects of struct pinctrl:

a) The data representation of the parsed mapping table, into:

   1) The top-level struct pinctrl object, a single entity returned
      by pinctrl_get().

   2) The parsed version of each mapping table entry, struct
      pinctrl_setting, of which there is one per mapping table entry.

b) The code that handles this; the code for (1) above is in core.c, and
   the code to parse/execute each entry in (2) above is in pinmux.c, while
   the iteration over multiple settings is lifted to core.c.

This will allow the following future changes:

1) pinctrl_get() API rework, so that struct pinctrl represents all states
   for the device, and the device can select between them without calling
   put()/get() again.

2) To support that, a struct pinctrl_state object will be inserted into
   the data model between the struct pinctrl and struct pinctrl_setting.

3) The mapping table will be extended to allow specification of pin config
   settings too. To support this, struct pinctrl_setting will be enhanced
   to store either mux settings or config settings, and functions will be
   added to pinconf.c to parse/execute pin configuration settings.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

4 files changed, 197 insertions, 376 deletions

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index aefc3394db91..535f8d53c289 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -460,14 +460,15 @@ EXPORT_SYMBOL_GPL(pinctrl_gpio_direction_output);
 
 static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name)
 {
-        struct pinctrl_dev *pctldev = NULL;
+        struct pinctrl_dev *pctldev;
         const char *devname;
         struct pinctrl *p;
         unsigned num_maps = 0;
-        int ret = -ENODEV;
+        int ret;
         struct pinctrl_maps *maps_node;
         int i;
         struct pinctrl_map const *map;
+        struct pinctrl_setting *setting;
 
         /* We must have both a dev and state name */
         if (WARN_ON(!dev || !name))
@@ -487,39 +488,50 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name)
                 dev_err(dev, "failed to alloc struct pinctrl\n");
                 return ERR_PTR(-ENOMEM);
         }
-        pinmux_init_pinctrl_handle(p);
+        p->dev = dev;
+        p->state = name;
+        INIT_LIST_HEAD(&p->settings);
 
         /* Iterate over the pin control maps to locate the right ones */
         for_each_maps(maps_node, i, map) {
+                /* Map must be for this device */
+                if (strcmp(map->dev_name, devname))
+                        continue;
+
+                /* State name must be the one we're looking for */
+                if (strcmp(map->name, name))
+                        continue;
+
                 /*
-                 * First, try to find the pctldev given in the map
+                 * Try to find the pctldev given in the map
                  */
                 pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
                 if (!pctldev) {
                         dev_err(dev, "unknown pinctrl device %s in map entry",
                                 map->ctrl_dev_name);
-                        pinmux_put(p);
-                        kfree(p);
                         /* Eventually, this should trigger deferred probe */
-                        return ERR_PTR(-ENODEV);
+                        ret = -ENODEV;
+                        goto error;
                 }
 
                 dev_dbg(dev, "in map, found pctldev %s to handle function %s",
                         dev_name(pctldev->dev), map->function);
 
-                /* Map must be for this device */
-                if (strcmp(map->dev_name, devname))
-                        continue;
+                setting = kzalloc(sizeof(*setting), GFP_KERNEL);
+                if (setting == NULL) {
+                        dev_err(dev,
+                                "failed to alloc struct pinctrl_setting\n");
+                        ret = -ENOMEM;
+                        goto error;
+                }
 
-                /* State name must be the one we're looking for */
-                if (strcmp(map->name, name))
-                        continue;
+                setting->pctldev = pctldev;
+                ret = pinmux_map_to_setting(map, setting);
+                if (ret < 0)
+                        goto error;
+
+                list_add_tail(&setting->node, &p->settings);
 
-                ret = pinmux_apply_muxmap(pctldev, p, dev, devname, map);
-                if (ret) {
-                        kfree(p);
-                        return ERR_PTR(ret);
-                }
                 num_maps++;
         }
 
@@ -541,6 +553,14 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name)
         list_add_tail(&p->node, &pinctrl_list);
 
         return p;
+
+error:
+        list_for_each_entry(setting, &p->settings, node)
+                pinmux_free_setting(setting);
+
+        kfree(p);
+
+        return ERR_PTR(ret);
 }
 
 /**
@@ -564,13 +584,18 @@ EXPORT_SYMBOL_GPL(pinctrl_get);
 
 static void pinctrl_put_locked(struct pinctrl *p)
 {
+        struct pinctrl_setting *setting, *n;
+
         if (p == NULL)
                 return;
 
         if (p->usecount)
                 pr_warn("releasing pin control handle with active users!\n");
-        /* Free the groups and all acquired pins */
-        pinmux_put(p);
+        list_for_each_entry_safe(setting, n, &p->settings, node) {
+                pinmux_free_setting(setting);
+                list_del(&setting->node);
+                kfree(setting);
+        }
 
         /* Remove from list */
         list_del(&p->node);
@@ -592,18 +617,24 @@ EXPORT_SYMBOL_GPL(pinctrl_put);
 
 static int pinctrl_enable_locked(struct pinctrl *p)
 {
-        int ret = 0;
+        struct pinctrl_setting *setting;
+        int ret;
 
         if (p == NULL)
                 return -EINVAL;
 
         if (p->usecount++ == 0) {
-                ret = pinmux_enable(p);
-                if (ret)
-                        p->usecount--;
+                list_for_each_entry(setting, &p->settings, node) {
+                        ret = pinmux_enable_setting(setting);
+                        if (ret < 0) {
+                                /* FIXME: Difficult to return to prev state */
+                                p->usecount--;
+                                return ret;
+                        }
+                }
         }
 
-        return ret;
+        return 0;
 }
 
 /**
@@ -622,11 +653,14 @@ EXPORT_SYMBOL_GPL(pinctrl_enable);
 
 static void pinctrl_disable_locked(struct pinctrl *p)
 {
+        struct pinctrl_setting *setting;
+
         if (p == NULL)
                 return;
 
         if (--p->usecount == 0) {