9 files changed, 149 insertions, 19 deletions

diff --git a/Documentation/devicetree/bindings/regmap/regmap.txt b/Documentation/devicetree/bindings/regmap/regmap.txt
new file mode 100644
index 000000000000..b494f8b8ef72
--- /dev/null
+++ b/Documentation/devicetree/bindings/regmap/regmap.txt
@@ -0,0 +1,47 @@
+Device-Tree binding for regmap
+
+The endianness mode of CPU & Device scenarios:
+Index     Device     Endianness properties
+---------------------------------------------------
+1         BE         'big-endian'
+2         LE         'little-endian'
+
+For one device driver, which will run in different scenarios above
+on different SoCs using the devicetree, we need one way to simplify
+this.
+
+Required properties:
+- {big,little}-endian: these are boolean properties, if absent
+  meaning that the CPU and the Device are in the same endianness mode,
+  these properties are for register values and all the buffers only.
+
+Examples:
+Scenario 1 : CPU in LE mode & device in LE mode.
+dev: dev@40031000 {
+              compatible = "name";
+              reg = <0x40031000 0x1000>;
+              ...
+};
+
+Scenario 2 : CPU in LE mode & device in BE mode.
+dev: dev@40031000 {
+              compatible = "name";
+              reg = <0x40031000 0x1000>;
+              ...
+              big-endian;
+};
+
+Scenario 3 : CPU in BE mode & device in BE mode.
+dev: dev@40031000 {
+              compatible = "name";
+              reg = <0x40031000 0x1000>;
+              ...
+};
+
+Scenario 4 : CPU in BE mode & device in LE mode.
+dev: dev@40031000 {
+              compatible = "name";
+              reg = <0x40031000 0x1000>;
+              ...
+              little-endian;
+};
diff --git a/MAINTAINERS b/MAINTAINERS
index f107230fc73d..8d9567186aa9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7595,6 +7595,7 @@ F:	fs/reiserfs/
 
 REGISTER MAP ABSTRACTION
 M:      Mark Brown <broonie@kernel.org>
+L:      linux-kernel@vger.kernel.org
 T:      git git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git
 S:      Supported
 F:      drivers/base/regmap/
diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index 4251570610c9..8a3f51f7b1b9 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -11,12 +11,15 @@ config REGMAP
 
 config REGMAP_I2C
         tristate
+        depends on I2C
 
 config REGMAP_SPI
         tristate
+        depends on SPI
 
 config REGMAP_SPMI
         tristate
+        depends on SPMI
 
 config REGMAP_MMIO
         tristate
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index bfc90b8547f2..0da5865df5b1 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -49,8 +49,10 @@ struct regmap_async {
 };
 
 struct regmap {
-        struct mutex mutex;
-        spinlock_t spinlock;
+        union {
+                struct mutex mutex;
+                spinlock_t spinlock;
+        };
         unsigned long spinlock_flags;
         regmap_lock lock;
         regmap_unlock unlock;
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 5617da6dc898..f1280dc356d0 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -269,8 +269,11 @@ static int regcache_default_sync(struct regmap *map, unsigned int min,
                 map->cache_bypass = 1;
                 ret = _regmap_write(map, reg, val);
                 map->cache_bypass = 0;
-                if (ret)
+                if (ret) {
+                        dev_err(map->dev, "Unable to sync register %#x. %d\n",
+                                reg, ret);
                         return ret;
+                }
                 dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val);
         }
 
@@ -615,8 +618,11 @@ static int regcache_sync_block_single(struct regmap *map, void *block,
                 ret = _regmap_write(map, regtmp, val);
 
                 map->cache_bypass = 0;
-                if (ret != 0)
+                if (ret != 0) {
+                        dev_err(map->dev, "Unable to sync register %#x. %d\n",
+                                regtmp, ret);
                         return ret;
+                }
                 dev_dbg(map->dev, "Synced register %#x, value %#x\n",
                         regtmp, val);
         }
@@ -641,6 +647,9 @@ static int regcache_sync_block_raw_flush(struct regmap *map, const void **data,
         map->cache_bypass = 1;
 
         ret = _regmap_raw_write(map, base, *data, count * val_bytes);
+        if (ret)
+                dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n",
+                        base, cur - map->reg_stride, ret);
 
         map->cache_bypass = 0;
 
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index 0c94b661c16f..5799a0b9e6cc 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -473,6 +473,7 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
 {
         struct rb_node *next;
         struct regmap_range_node *range_node;
+        const char *devname = "dummy";
 
         /* If we don't have the debugfs root yet, postpone init */
         if (!regmap_debugfs_root) {
@@ -491,12 +492,15 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
         INIT_LIST_HEAD(&map->debugfs_off_cache);
         mutex_init(&map->cache_lock);
 
+        if (map->dev)
+                devname = dev_name(map->dev);
+
         if (name) {
                 map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
-                                              dev_name(map->dev), name);
+                                              devname, name);
                 name = map->debugfs_name;
         } else {
-                name = dev_name(map->dev);
+                name = devname;
         }
 
         map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c
index ca193d1ef47c..053150a7f9f2 100644
--- a/drivers/base/regmap/regmap-i2c.c
+++ b/drivers/base/regmap/regmap-i2c.c
@@ -168,6 +168,8 @@ static struct regmap_bus regmap_i2c = {
         .write = regmap_i2c_write,
         .gather_write = regmap_i2c_gather_write,
         .read = regmap_i2c_read,
+        .reg_format_endian_default = REGMAP_ENDIAN_BIG,
+        .val_format_endian_default = REGMAP_ENDIAN_BIG,
 };
 
 static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c,
diff --git a/drivers/base/regmap/regmap-spi.c b/drivers/base/regmap/regmap-spi.c
index 0eb3097c0d76..53d1148e80a0 100644
--- a/drivers/base/regmap/regmap-spi.c
+++ b/drivers/base/regmap/regmap-spi.c
@@ -109,6 +109,8 @@ static struct regmap_bus regmap_spi = {
         .async_alloc = regmap_spi_async_alloc,
         .read = regmap_spi_read,
         .read_flag_mask = 0x80,
+        .reg_format_endian_default = REGMAP_ENDIAN_BIG,
+        .val_format_endian_default = REGMAP_ENDIAN_BIG,
 };
 
 /**
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