pinctrl: disallow map table entries with NULL dev_name field

Hog entries are mapping table entries with .ctrl_dev_name == .dev_name.
All other mapping table entries need .dev_name set so that they will
match some pinctrl_get() call. All extant PIN_MAP*() macros set
.dev_name.

So, there is no reason to allow mapping table entries without .dev_name
set. Update the code and documentation to disallow this.

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

1 files changed, 22 insertions, 51 deletions

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index fb3fbb76932e..5411e32bb3f6 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -479,24 +479,21 @@ EXPORT_SYMBOL_GPL(pinctrl_gpio_direction_output);
 static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name)
 {
         struct pinctrl_dev *pctldev = NULL;
-        const char *devname = NULL;
+        const char *devname;
         struct pinctrl *p;
-        bool found_map;
         unsigned num_maps = 0;
         int ret = -ENODEV;
         struct pinctrl_maps *maps_node;
         int i;
         struct pinctrl_map const *map;
 
-        /* We must have dev or ID or both */
-        if (!dev && !name)
+        /* We must have a dev name */
+        if (WARN_ON(!dev))
                 return ERR_PTR(-EINVAL);
 
-        if (dev)
-                devname = dev_name(dev);
+        devname = dev_name(dev);
 
-        pr_debug("get pin control handle %s for device %s\n", name,
-                 devname ? devname : "(none)");
+        pr_debug("get pin control handle device %s state %s\n", devname, name);
 
         /*
          * create the state cookie holder struct pinctrl for each
@@ -511,8 +508,6 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name)
 
         /* Iterate over the pin control maps to locate the right ones */
         for_each_maps(maps_node, i, map) {
-                found_map = false;
-
                 /*
                  * First, try to find the pctldev given in the map
                  */
@@ -529,6 +524,10 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name)
                 pr_debug("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;
+
                 /*
                  * If we're looking for a specific named map, this must match,
                  * else we loop and look for the next.
@@ -540,30 +539,12 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name)
                                 continue;
                 }
 
-                /*
-                 * This is for the case where no device name is given, we
-                 * already know that the function name matches from above
-                 * code.
-                 */
-                if (!map->dev_name && (name != NULL))
-                        found_map = true;
-
-                /* If the mapping has a device set up it must match */
-                if (map->dev_name &&
-                    (!devname || !strcmp(map->dev_name, devname)))
-                        /* MATCH! */
-                        found_map = true;
-
-                /* If this map is applicable, then apply it */
-                if (found_map) {
-                        ret = pinmux_apply_muxmap(pctldev, p, dev,
-                                                   devname, map);
-                        if (ret) {
-                                kfree(p);
-                                return ERR_PTR(ret);
-                        }
-                        num_maps++;
+                ret = pinmux_apply_muxmap(pctldev, p, dev, devname, map);
+                if (ret) {
+                        kfree(p);
+                        return ERR_PTR(ret);
                 }
+                num_maps++;
         }
 
         /*
@@ -578,9 +559,7 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name)
                 dev_info(dev, "zero maps found for mapping %s\n", name);
 
         pr_debug("found %u mux maps for device %s, UD %s\n",
-                 num_maps,
-                 devname ? devname : "(anonymous)",
-                 name ? name : "(undefined)");
+                 num_maps, devname, name ? name : "(undefined)");
 
         /* Add the pinmux to the global list */
         mutex_lock(&pinctrl_list_mutex);
@@ -707,14 +686,11 @@ int pinctrl_register_mappings(struct pinctrl_map const *maps,
                         return -EINVAL;
                 }
 
-                if (!maps[i].dev_name)
-                        pr_debug("add system map %s function %s with no device\n",
-                                 maps[i].name,
-                                 maps[i].function);
-                else
-                        pr_debug("register map %s, function %s\n",
-                                 maps[i].name,
-                                 maps[i].function);
+                if (!maps[i].dev_name) {
+                        pr_err("failed to register map %s (%d): no device given\n",
+                                        maps[i].name, i);
+                        return -EINVAL;
+                }
         }
 
         maps_node = kzalloc(sizeof(*maps_node), GFP_KERNEL);
@@ -938,13 +914,8 @@ static int pinctrl_maps_show(struct seq_file *s, void *what)
         mutex_lock(&pinctrl_maps_mutex);
         for_each_maps(maps_node, i, map) {
                 seq_printf(s, "%s:\n", map->name);
-                if (map->dev_name)
-                        seq_printf(s, "  device: %s\n",
-                                   map->dev_name);
-                else
-                        seq_printf(s, "  SYSTEM MUX\n");
-                seq_printf(s, "  controlling device %s\n",
-                           map->ctrl_dev_name);
+                seq_printf(s, "  device: %s\n", map->dev_name);
+                seq_printf(s, "  controlling device %s\n", map->ctrl_dev_name);
                 seq_printf(s, "  function: %s\n", map->function);
                 seq_printf(s, "  group: %s\n", map->group ? map->group :
                            "(default)");