From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/mfd/syscon.c | 241 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 241 insertions(+) create mode 100644 drivers/mfd/syscon.c (limited to 'drivers/mfd/syscon.c') 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 + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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 "); +MODULE_DESCRIPTION("System Control driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3-54-g00ecf