Initial import

1 files changed, 241 insertions, 0 deletions

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
new file mode 100644
index 000000000..176bf0fa2
--- /dev/null
+++ b/drivers/mfd/syscon.c
@@ -0,0 +1,241 @@
+/*
+ * System Control Driver
+ *
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ * Copyright (C) 2012 Linaro Ltd.
+ *
+ * Author: Dong Aisheng <dong.aisheng@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#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>
+#include <linux/platform_data/syscon.h>
+#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 struct syscon *of_syscon_register(struct device_node *np)
+{
+	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 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 *entry, *syscon = NULL;
+
+	spin_lock(&syscon_list_slock);
+
+	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;
+}
+EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
+
+struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
+{
+	struct device_node *syscon_np;
+	struct regmap *regmap;
+
+	syscon_np = of_find_compatible_node(NULL, NULL, s);
+	if (!syscon_np)
+		return ERR_PTR(-ENODEV);
+
+	regmap = syscon_node_to_regmap(syscon_np);
+	of_node_put(syscon_np);
+
+	return regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
+
+static int syscon_match_pdevname(struct device *dev, void *data)
+{
+	return !strcmp(dev_name(dev), (const char *)data);
+}
+
+struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
+{
+	struct device *dev;
+	struct syscon *syscon;
+
+	dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
+				 syscon_match_pdevname);
+	if (!dev)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	syscon = dev_get_drvdata(dev);
+
+	return syscon->regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
+
+struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
+					const char *property)
+{
+	struct device_node *syscon_np;
+	struct regmap *regmap;
+
+	if (property)
+		syscon_np = of_parse_phandle(np, property, 0);
+	else
+		syscon_np = np;
+
+	if (!syscon_np)
+		return ERR_PTR(-ENODEV);
+
+	regmap = syscon_node_to_regmap(syscon_np);
+	of_node_put(syscon_np);
+
+	return regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
+
+static int syscon_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct syscon_platform_data *pdata = dev_get_platdata(dev);
+	struct syscon *syscon;
+	struct resource *res;
+	void __iomem *base;
+
+	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
+	if (!syscon)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOENT;
+
+	base = devm_ioremap(dev, res->start, resource_size(res));
+	if (!base)
+		return -ENOMEM;
+
+	syscon_regmap_config.max_register = res->end - res->start - 3;
+	if (pdata)
+		syscon_regmap_config.name = pdata->label;
+	syscon->regmap = devm_regmap_init_mmio(dev, base,
+					&syscon_regmap_config);
+	if (IS_ERR(syscon->regmap)) {
+		dev_err(dev, "regmap init failed\n");
+		return PTR_ERR(syscon->regmap);
+	}
+
+	platform_set_drvdata(pdev, syscon);
+
+	dev_dbg(dev, "regmap %pR registered\n", res);
+
+	return 0;
+}
+
+static const struct platform_device_id syscon_ids[] = {
+	{ "syscon", },
+	{ }
+};
+
+static struct platform_driver syscon_driver = {
+	.driver = {
+		.name = "syscon",
+	},
+	.probe		= syscon_probe,
+	.id_table	= syscon_ids,
+};
+
+static int __init syscon_init(void)
+{
+	return platform_driver_register(&syscon_driver);
+}
+postcore_initcall(syscon_init);
+
+static void __exit syscon_exit(void)
+{
+	platform_driver_unregister(&syscon_driver);
+}
+module_exit(syscon_exit);
+
+MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
+MODULE_DESCRIPTION("System Control driver");
+MODULE_LICENSE("GPL v2");