1 files changed, 74 insertions, 22 deletions

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index ca15878ce5c0..72373b113885 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/list.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_platform.h>
@@ -22,31 +23,94 @@
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
+#include <linux/slab.h>
 
 static struct platform_driver syscon_driver;
 
+static DEFINE_SPINLOCK(syscon_list_slock);
+static LIST_HEAD(syscon_list);
+
 struct syscon {
+        struct device_node *np;
         struct regmap *regmap;
+        struct list_head list;
+};
+
+static struct regmap_config syscon_regmap_config = {
+        .reg_bits = 32,
+        .val_bits = 32,
+        .reg_stride = 4,
 };
 
-static int syscon_match_node(struct device *dev, void *data)
+static struct syscon *of_syscon_register(struct device_node *np)
 {
-        struct device_node *dn = data;
+        struct syscon *syscon;
+        struct regmap *regmap;
+        void __iomem *base;
+        int ret;
+        struct regmap_config syscon_config = syscon_regmap_config;
+
+        if (!of_device_is_compatible(np, "syscon"))
+                return ERR_PTR(-EINVAL);
+
+        syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
+        if (!syscon)
+                return ERR_PTR(-ENOMEM);
+
+        base = of_iomap(np, 0);
+        if (!base) {
+                ret = -ENOMEM;
+                goto err_map;
+        }
+
+        /* Parse the device's DT node for an endianness specification */
+        if (of_property_read_bool(np, "big-endian"))
+                syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
+         else if (of_property_read_bool(np, "little-endian"))
+                syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
+
+        regmap = regmap_init_mmio(NULL, base, &syscon_config);
+        if (IS_ERR(regmap)) {
+                pr_err("regmap init failed\n");
+                ret = PTR_ERR(regmap);
+                goto err_regmap;
+        }
+
+        syscon->regmap = regmap;
+        syscon->np = np;
+
+        spin_lock(&syscon_list_slock);
+        list_add_tail(&syscon->list, &syscon_list);
+        spin_unlock(&syscon_list_slock);
 
-        return (dev->of_node == dn) ? 1 : 0;
+        return syscon;
+
+err_regmap:
+        iounmap(base);
+err_map:
+        kfree(syscon);
+        return ERR_PTR(ret);
 }
 
 struct regmap *syscon_node_to_regmap(struct device_node *np)
 {
-        struct syscon *syscon;
-        struct device *dev;
+        struct syscon *entry, *syscon = NULL;
 
-        dev = driver_find_device(&syscon_driver.driver, NULL, np,
-                                 syscon_match_node);
-        if (!dev)
-                return ERR_PTR(-EPROBE_DEFER);
+        spin_lock(&syscon_list_slock);
 
-        syscon = dev_get_drvdata(dev);
+        list_for_each_entry(entry, &syscon_list, list)
+                if (entry->np == np) {
+                        syscon = entry;
+                        break;
+                }
+
+        spin_unlock(&syscon_list_slock);
+
+        if (!syscon)
+                syscon = of_syscon_register(np);
+
+        if (IS_ERR(syscon))
+                return ERR_CAST(syscon);
 
         return syscon->regmap;
 }
@@ -110,17 +174,6 @@ struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
 }
 EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
 
-static const struct of_device_id of_syscon_match[] = {
-        { .compatible = "syscon", },
-        { },
-};
-
-static struct regmap_config syscon_regmap_config = {
-        .reg_bits = 32,
-        .val_bits = 32,
-        .reg_stride = 4,
-};
-
 static int syscon_probe(struct platform_device *pdev)
 {
         struct device *dev = &pdev->dev;
@@ -167,7 +220,6 @@ static struct platform_driver syscon_driver = {
         .driver = {
                 .name = "syscon",
                 .owner = THIS_MODULE,
-                .of_match_table = of_syscon_match,
         },
         .probe          = syscon_probe,
         .id_table       = syscon_ids,