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>

diff --git a/Documentation/pinctrl.txt b/Documentation/pinctrl.txt
index ee3266b..fa9163a 100644 (file)
--- a/Documentation/pinctrl.txt
+++ b/Documentation/pinctrl.txt
@@ -494,14 +494,10 @@ Definitions:
     {"map-i2c0", i2c0, pinctrl0, fi2c0, gi2c0}
   }
 
-  Every map must be assigned a symbolic name, pin controller and function.
-  The group is not compulsory - if it is omitted the first group presented by
-  the driver as applicable for the function will be selected, which is
-  useful for simple cases.
-
-  The device name is present in map entries tied to specific devices. Maps
-  without device names are referred to as SYSTEM pinmuxes, such as can be taken
-  by the machine implementation on boot and not tied to any specific device.
+  Every map must be assigned a state name, pin controller, device and
+  function. The group is not compulsory - if it is omitted the first group
+  presented by the driver as applicable for the function will be selected,
+  which is useful for simple cases.
 
   It is possible to map several groups to the same combination of device,
   pin controller and function. This is for cases where a certain function on
@@ -983,8 +979,7 @@ after this you should be able to see this in the debugfs listing of all pins.
 System pin control hogging
 ==========================
 
-A system pin control map entry, i.e. a pin control setting that does not have
-a device associated with it, can be hogged by the core when the pin controller
+Pin control map entries can be hogged by the core when the pin controller
 is registered. This means that the core will attempt to call pinctrl_get() and
 pinctrl_enable() on it immediately after the pin control device has been
 registered.

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index fb3fbb7..5411e32 100644 (file)
--- 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)");

diff --git a/include/linux/pinctrl/machine.h b/include/linux/pinctrl/machine.h
index af145d5..400f192 100644 (file)
--- a/include/linux/pinctrl/machine.h
+++ b/include/linux/pinctrl/machine.h
@@ -46,13 +46,6 @@ struct pinctrl_map {
        { .name = a, .ctrl_dev_name = b, .function = c, .dev_name = d }
 
 /*
- * Convenience macro to map a system function onto a certain pinctrl device.
- * System functions are not assigned to a particular device.
- */
-#define PIN_MAP_SYS(a, b, c) \
-       { .name = a, .ctrl_dev_name = b, .function = c }
-
-/*
  * Convenience macro to map a system function onto a certain pinctrl device,
  * to be hogged by the pin control core until the system shuts down.
  */