X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=drivers%2Fcore%2Fsyscon-uclass.c;h=303e166a69c1b769f5006712c06dc3d855e1c2c4;hb=9f9ce3c369b7fbcc47496331ff28fad80302a42c;hp=e03f46af5739d7156ad0270a438e4744496e535f;hpb=532f2435cfe94e54e01ba68572daa853d7752afa;p=u-boot

diff --git a/drivers/core/syscon-uclass.c b/drivers/core/syscon-uclass.c
index e03f46af57..303e166a69 100644
--- a/drivers/core/syscon-uclass.c
+++ b/drivers/core/syscon-uclass.c
@@ -1,8 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2015 Google, Inc
  * Written by Simon Glass <sjg@chromium.org>
- *
- * SPDX-License-Identifier:	GPL-2.0+
  */
 
 #include <common.h>
@@ -15,6 +14,15 @@
 #include <dm/root.h>
 #include <linux/err.h>
 
+/*
+ * Caution:
+ * This API requires the given device has alerady been bound to syscon driver.
+ * For example,
+ *    compatible = "syscon", "simple-mfd";
+ * works, but
+ *    compatible = "simple-mfd", "syscon";
+ * does not.  The behavior is different from Linux.
+ */
 struct regmap *syscon_get_regmap(struct udevice *dev)
 {
 	struct syscon_uc_info *priv;
@@ -29,7 +37,20 @@ static int syscon_pre_probe(struct udevice *dev)
 {
 	struct syscon_uc_info *priv = dev_get_uclass_priv(dev);
 
-	return regmap_init_mem(dev, &priv->regmap);
+	/*
+	 * With OF_PLATDATA we really have no way of knowing the format of
+	 * the device-specific platform data. So we assume that it starts with
+	 * a 'reg' member, and this holds a single address and size. Drivers
+	 * using OF_PLATDATA will need to ensure that this is true.
+	 */
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+	struct syscon_base_platdata *plat = dev_get_platdata(dev);
+
+	return regmap_init_mem_platdata(dev, plat->reg, ARRAY_SIZE(plat->reg),
+					&priv->regmap);
+#else
+	return regmap_init_mem(dev_ofnode(dev), &priv->regmap);
+#endif
 }
 
 int syscon_get_by_driver_data(ulong driver_data, struct udevice **devp)
@@ -82,3 +103,72 @@ UCLASS_DRIVER(syscon) = {
 	.per_device_auto_alloc_size = sizeof(struct syscon_uc_info),
 	.pre_probe = syscon_pre_probe,
 };
+
+static const struct udevice_id generic_syscon_ids[] = {
+	{ .compatible = "syscon" },
+	{ }
+};
+
+U_BOOT_DRIVER(generic_syscon) = {
+	.name	= "syscon",
+	.id	= UCLASS_SYSCON,
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+	.bind           = dm_scan_fdt_dev,
+#endif
+	.of_match = generic_syscon_ids,
+};
+
+/*
+ * Linux-compatible syscon-to-regmap
+ * The syscon node can be bound to another driver, but still works
+ * as a syscon provider.
+ */
+static LIST_HEAD(syscon_list);
+
+struct syscon {
+	ofnode node;
+	struct regmap *regmap;
+	struct list_head list;
+};
+
+static struct syscon *of_syscon_register(ofnode node)
+{
+	struct syscon *syscon;
+	int ret;
+
+	if (!ofnode_device_is_compatible(node, "syscon"))
+		return ERR_PTR(-EINVAL);
+
+	syscon = malloc(sizeof(*syscon));
+	if (!syscon)
+		return ERR_PTR(-ENOMEM);
+
+	ret = regmap_init_mem(node, &syscon->regmap);
+	if (ret) {
+		free(syscon);
+		return ERR_PTR(ret);
+	}
+
+	list_add_tail(&syscon->list, &syscon_list);
+
+	return syscon;
+}
+
+struct regmap *syscon_node_to_regmap(ofnode node)
+{
+	struct syscon *entry, *syscon = NULL;
+
+	list_for_each_entry(entry, &syscon_list, list)
+		if (ofnode_equal(entry->node, node)) {
+			syscon = entry;
+			break;
+		}
+
+	if (!syscon)
+		syscon = of_syscon_register(node);
+
+	if (IS_ERR(syscon))
+		return ERR_CAST(syscon);
+
+	return syscon->regmap;
+}