3 files changed, 66 insertions, 1 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 2eb71970488..b986b8660b0 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -45,6 +45,7 @@ struct regmap {
 	struct regmap_format format;  /* Buffer format */
 	const struct regmap_bus *bus;
 	void *bus_context;
+	const char *name;
 
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs;
diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index fc69d29d272..0d233cc1c7f 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -206,6 +206,8 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 	if (!d)
 		return -ENOMEM;
 
+	*data = d;
+
 	d->status_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 				GFP_KERNEL);
 	if (!d->status_buf)
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 35729490579..0bcda488f11 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -199,6 +199,15 @@ static void regmap_unlock_spinlock(struct regmap *map)
 	spin_unlock(&map->spinlock);
 }
 
+static void dev_get_regmap_release(struct device *dev, void *res)
+{
+	/*
+	 * We don't actually have anything to do here; the goal here
+	 * is not to manage the regmap but to provide a simple way to
+	 * get the regmap back given a struct device.
+	 */
+}
+
 /**
  * regmap_init(): Initialise register map
  *
@@ -216,7 +225,7 @@ struct regmap *regmap_init(struct device *dev,
 			   void *bus_context,
 			   const struct regmap_config *config)
 {
-	struct regmap *map;
+	struct regmap *map, **m;
 	int ret = -EINVAL;
 
 	if (!bus || !config)
@@ -257,6 +266,7 @@ struct regmap *regmap_init(struct device *dev,
 	map->volatile_reg = config->volatile_reg;
 	map->precious_reg = config->precious_reg;
 	map->cache_type = config->cache_type;
+	map->name = config->name;
 
 	if (config->read_flag_mask || config->write_flag_mask) {
 		map->read_flag_mask = config->read_flag_mask;
@@ -360,8 +370,19 @@ struct regmap *regmap_init(struct device *dev,
 	if (ret < 0)
 		goto err_free_workbuf;
 
+	/* Add a devres resource for dev_get_regmap() */
+	m = devres_alloc(dev_get_regmap_release, sizeof(*m), GFP_KERNEL);
+	if (!m) {
+		ret = -ENOMEM;
+		goto err_cache;
+	}
+	*m = map;
+	devres_add(dev, m);
+
 	return map;
 
+err_cache:
+	regcache_exit(map);
 err_free_workbuf:
 	kfree(map->work_buf);
 err_map:
@@ -465,6 +486,44 @@ void regmap_exit(struct regmap *map)
 }
 EXPORT_SYMBOL_GPL(regmap_exit);
 
+static int dev_get_regmap_match(struct device *dev, void *res, void *data)
+{
+	struct regmap **r = res;
+	if (!r || !*r) {
+		WARN_ON(!r || !*r);
+		return 0;
+	}
+
+	/* If the user didn't specify a name match any */
+	if (data)
+		return (*r)->name == data;
+	else
+		return 1;
+}
+
+/**
+ * dev_get_regmap(): Obtain the regmap (if any) for a device
+ *
+ * @dev: Device to retrieve the map for
+ * @name: Optional name for the register map, usually NULL.
+ *
+ * Returns the regmap for the device if one is present, or NULL.  If
+ * name is specified then it must match the name specified when
+ * registering the device, if it is NULL then the first regmap found
+ * will be used.  Devices with multiple register maps are very rare,
+ * generic code should normally not need to specify a name.
+ */
+struct regmap *dev_get_regmap(struct device *dev, const char *name)
+{
+	struct regmap **r = devres_find(dev, dev_get_regmap_release,
+					dev_get_regmap_match, (void *)name);
+
+	if (!r)
+		return NULL;
+	return *r;
+}
+EXPORT_SYMBOL_GPL(dev_get_regmap);
+
 static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 			     const void *val, size_t val_len)
 {
@@ -768,6 +827,9 @@ static int _regmap_read(struct regmap *map, unsigned int reg,
 		trace_regmap_reg_read(map->dev, reg, *val);
 	}
 
+	if (ret == 0 && !map->cache_bypass)
+		regcache_write(map, reg, *val);
+
 	return ret;
 }