Merge tag 'regmap-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "The main update this time around is the addition of a standard DT
  binding for specifying the endianness of devices.  This allows drivers
  to support any endianness of device register map without any code,
  useful for configurable IP blocks.

  There's also a few bug fixes that I didn't get round to sending, none
  of them terribly severe or new, and a reduction in size for struct
  regmap"

* tag 'regmap-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: Fix debugfs-file 'registers' mode
  regmap: fix possible ZERO_SIZE_PTR pointer dereferencing error.
  regmap: debugfs: fix possbile NULL pointer dereference
  regmap: fix NULL pointer dereference in _regmap_write/read
  regmap: fix NULL pointer dereference in regmap_get_val_endian
  regmap: cache: Do not fail silently from regcache_sync calls
  regmap: change struct regmap's internal locks as union
  regmap: Split regmap_get_endian() in two functions
  regmap: of_regmap_get_endian() cleanup
  regmap: Fix DT endianess parsing logic
  regmap: Add explicit dependencies to catch "select" misuse
  regmap: Restore L: linux-kernel@vger.kernel.org entry
  regmap: Add the DT binding documentation for endianness
  regmap: add DT endianness binding support.

1 files changed, 73 insertions, 13 deletions

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 1cf427bc0d4a..d2f8a818d200 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -15,6 +15,7 @@
 #include <linux/export.h>
 #include <linux/mutex.h>
 #include <linux/err.h>
+#include <linux/of.h>
 #include <linux/rbtree.h>
 #include <linux/sched.h>
 
@@ -448,6 +449,71 @@ int regmap_attach_dev(struct device *dev, struct regmap *map,
 }
 EXPORT_SYMBOL_GPL(regmap_attach_dev);
 
+static enum regmap_endian regmap_get_reg_endian(const struct regmap_bus *bus,
+                                        const struct regmap_config *config)
+{
+        enum regmap_endian endian;
+
+        /* Retrieve the endianness specification from the regmap config */
+        endian = config->reg_format_endian;
+
+        /* If the regmap config specified a non-default value, use that */
+        if (endian != REGMAP_ENDIAN_DEFAULT)
+                return endian;
+
+        /* Retrieve the endianness specification from the bus config */
+        if (bus && bus->reg_format_endian_default)
+                endian = bus->reg_format_endian_default;
+
+        /* If the bus specified a non-default value, use that */
+        if (endian != REGMAP_ENDIAN_DEFAULT)
+                return endian;
+
+        /* Use this if no other value was found */
+        return REGMAP_ENDIAN_BIG;
+}
+
+static enum regmap_endian regmap_get_val_endian(struct device *dev,
+                                        const struct regmap_bus *bus,
+                                        const struct regmap_config *config)
+{
+        struct device_node *np;
+        enum regmap_endian endian;
+
+        /* Retrieve the endianness specification from the regmap config */
+        endian = config->val_format_endian;
+
+        /* If the regmap config specified a non-default value, use that */
+        if (endian != REGMAP_ENDIAN_DEFAULT)
+                return endian;
+
+        /* If the dev and dev->of_node exist try to get endianness from DT */
+        if (dev && dev->of_node) {
+                np = dev->of_node;
+
+                /* Parse the device's DT node for an endianness specification */
+                if (of_property_read_bool(np, "big-endian"))
+                        endian = REGMAP_ENDIAN_BIG;
+                else if (of_property_read_bool(np, "little-endian"))
+                        endian = REGMAP_ENDIAN_LITTLE;
+
+                /* If the endianness was specified in DT, use that */
+                if (endian != REGMAP_ENDIAN_DEFAULT)
+                        return endian;
+        }
+
+        /* Retrieve the endianness specification from the bus config */
+        if (bus && bus->val_format_endian_default)
+                endian = bus->val_format_endian_default;
+
+        /* If the bus specified a non-default value, use that */
+        if (endian != REGMAP_ENDIAN_DEFAULT)
+                return endian;
+
+        /* Use this if no other value was found */
+        return REGMAP_ENDIAN_BIG;
+}
+
 /**
  * regmap_init(): Initialise register map
  *
@@ -551,17 +617,8 @@ struct regmap *regmap_init(struct device *dev,
                 map->reg_read  = _regmap_bus_read;
         }
 
-        reg_endian = config->reg_format_endian;
-        if (reg_endian == REGMAP_ENDIAN_DEFAULT)
-                reg_endian = bus->reg_format_endian_default;
-        if (reg_endian == REGMAP_ENDIAN_DEFAULT)
-                reg_endian = REGMAP_ENDIAN_BIG;
-
-        val_endian = config->val_format_endian;
-        if (val_endian == REGMAP_ENDIAN_DEFAULT)
-                val_endian = bus->val_format_endian_default;
-        if (val_endian == REGMAP_ENDIAN_DEFAULT)
-                val_endian = REGMAP_ENDIAN_BIG;
+        reg_endian = regmap_get_reg_endian(bus, config);
+        val_endian = regmap_get_val_endian(dev, bus, config);
 
         switch (config->reg_bits + map->reg_shift) {
         case 2:
@@ -1408,7 +1465,7 @@ int _regmap_write(struct regmap *map, unsigned int reg,
         }
 
 #ifdef LOG_DEVICE
-        if (strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
+        if (map->dev && strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
                 dev_info(map->dev, "%x <= %x\n", reg, val);
 #endif
 
@@ -1659,6 +1716,9 @@ out:
         } else {
                 void *wval;
 
+                if (!val_count)
+                        return -EINVAL;
+
                 wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
                 if (!wval) {
                         dev_err(map->dev, "Error in memory allocation\n");
@@ -2058,7 +2118,7 @@ static int _regmap_read(struct regmap *map, unsigned int reg,
         ret = map->reg_read(context, reg, val);
         if (ret == 0) {
 #ifdef LOG_DEVICE
-                if (strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
+                if (map->dev && strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
                         dev_info(map->dev, "%x => %x\n", reg, *val);
 #endif