first commit

1 files changed, 189 insertions, 0 deletions

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
new file mode 100644
index 000000000..962a6e17a
--- /dev/null
+++ b/drivers/mfd/syscon.c
@@ -0,0 +1,189 @@
+/*
+ * 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/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+static struct platform_driver syscon_driver;
+
+struct syscon {
+	void __iomem *base;
+	struct regmap *regmap;
+};
+
+static int syscon_match_node(struct device *dev, void *data)
+{
+	struct device_node *dn = data;
+
+	return (dev->of_node == dn) ? 1 : 0;
+}
+
+struct regmap *syscon_node_to_regmap(struct device_node *np)
+{
+	struct syscon *syscon;
+	struct device *dev;
+
+	dev = driver_find_device(&syscon_driver.driver, NULL, np,
+				 syscon_match_node);
+	if (!dev)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	syscon = dev_get_drvdata(dev);
+
+	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)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	const struct platform_device_id *id = platform_get_device_id(pdev);
+
+	if (id)
+		if (!strcmp(id->name, (const char *)data))
+			return 1;
+
+	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;
+
+	syscon_np = of_parse_phandle(np, property, 0);
+	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 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;
+	struct syscon *syscon;
+	struct resource *res;
+
+	syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
+	if (!syscon)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOENT;
+
+	syscon->base = devm_ioremap(dev, res->start, resource_size(res));
+	if (!syscon->base)
+		return -ENOMEM;
+
+	syscon_regmap_config.max_register = res->end - res->start - 3;
+	syscon->regmap = devm_regmap_init_mmio(dev, syscon->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_info(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",
+		.owner = THIS_MODULE,
+		.of_match_table = of_syscon_match,
+	},
+	.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");