283 lines
6.5 KiB
C
283 lines
6.5 KiB
C
/*
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* System Control Driver
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*
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* Copyright (C) 2012 Freescale Semiconductor, Inc.
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* Copyright (C) 2012 Linaro Ltd.
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*
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* Author: Dong Aisheng <dong.aisheng@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/err.h>
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#include <linux/hwspinlock.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_platform.h>
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#include <linux/platform_data/syscon.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/mfd/syscon.h>
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#include <linux/slab.h>
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static struct platform_driver syscon_driver;
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static DEFINE_SPINLOCK(syscon_list_slock);
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static LIST_HEAD(syscon_list);
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struct syscon {
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struct device_node *np;
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struct regmap *regmap;
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struct list_head list;
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};
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static const struct regmap_config syscon_regmap_config = {
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.reg_bits = 32,
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.val_bits = 32,
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.reg_stride = 4,
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};
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static struct syscon *of_syscon_register(struct device_node *np)
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{
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struct syscon *syscon;
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struct regmap *regmap;
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void __iomem *base;
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u32 reg_io_width;
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int ret;
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struct regmap_config syscon_config = syscon_regmap_config;
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struct resource res;
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if (!of_device_is_compatible(np, "syscon"))
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return ERR_PTR(-EINVAL);
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syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
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if (!syscon)
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return ERR_PTR(-ENOMEM);
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if (of_address_to_resource(np, 0, &res)) {
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ret = -ENOMEM;
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goto err_map;
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}
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base = ioremap(res.start, resource_size(&res));
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if (!base) {
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ret = -ENOMEM;
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goto err_map;
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}
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/* Parse the device's DT node for an endianness specification */
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if (of_property_read_bool(np, "big-endian"))
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syscon_config.val_format_endian = REGMAP_ENDIAN_BIG;
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else if (of_property_read_bool(np, "little-endian"))
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syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
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else if (of_property_read_bool(np, "native-endian"))
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syscon_config.val_format_endian = REGMAP_ENDIAN_NATIVE;
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/*
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* search for reg-io-width property in DT. If it is not provided,
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* default to 4 bytes. regmap_init_mmio will return an error if values
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* are invalid so there is no need to check them here.
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*/
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ret = of_property_read_u32(np, "reg-io-width", ®_io_width);
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if (ret)
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reg_io_width = 4;
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ret = of_hwspin_lock_get_id(np, 0);
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if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
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syscon_config.use_hwlock = true;
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syscon_config.hwlock_id = ret;
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syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
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} else if (ret < 0) {
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switch (ret) {
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case -ENOENT:
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/* Ignore missing hwlock, it's optional. */
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break;
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default:
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pr_err("Failed to retrieve valid hwlock: %d\n", ret);
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/* fall-through */
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case -EPROBE_DEFER:
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goto err_regmap;
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}
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}
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syscon_config.reg_stride = reg_io_width;
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syscon_config.val_bits = reg_io_width * 8;
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syscon_config.max_register = resource_size(&res) - reg_io_width;
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regmap = regmap_init_mmio(NULL, base, &syscon_config);
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if (IS_ERR(regmap)) {
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pr_err("regmap init failed\n");
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ret = PTR_ERR(regmap);
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goto err_regmap;
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}
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syscon->regmap = regmap;
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syscon->np = np;
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spin_lock(&syscon_list_slock);
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list_add_tail(&syscon->list, &syscon_list);
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spin_unlock(&syscon_list_slock);
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return syscon;
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err_regmap:
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iounmap(base);
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err_map:
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kfree(syscon);
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return ERR_PTR(ret);
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}
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struct regmap *syscon_node_to_regmap(struct device_node *np)
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{
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struct syscon *entry, *syscon = NULL;
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spin_lock(&syscon_list_slock);
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list_for_each_entry(entry, &syscon_list, list)
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if (entry->np == np) {
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syscon = entry;
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break;
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}
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spin_unlock(&syscon_list_slock);
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if (!syscon)
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syscon = of_syscon_register(np);
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if (IS_ERR(syscon))
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return ERR_CAST(syscon);
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return syscon->regmap;
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}
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EXPORT_SYMBOL_GPL(syscon_node_to_regmap);
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struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
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{
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struct device_node *syscon_np;
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struct regmap *regmap;
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syscon_np = of_find_compatible_node(NULL, NULL, s);
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if (!syscon_np)
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return ERR_PTR(-ENODEV);
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regmap = syscon_node_to_regmap(syscon_np);
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of_node_put(syscon_np);
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return regmap;
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}
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EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible);
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static int syscon_match_pdevname(struct device *dev, void *data)
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{
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return !strcmp(dev_name(dev), (const char *)data);
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}
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struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
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{
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struct device *dev;
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struct syscon *syscon;
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dev = driver_find_device(&syscon_driver.driver, NULL, (void *)s,
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syscon_match_pdevname);
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if (!dev)
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return ERR_PTR(-EPROBE_DEFER);
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syscon = dev_get_drvdata(dev);
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return syscon->regmap;
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}
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EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
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struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
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const char *property)
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{
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struct device_node *syscon_np;
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struct regmap *regmap;
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if (property)
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syscon_np = of_parse_phandle(np, property, 0);
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else
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syscon_np = np;
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if (!syscon_np)
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return ERR_PTR(-ENODEV);
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regmap = syscon_node_to_regmap(syscon_np);
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of_node_put(syscon_np);
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return regmap;
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}
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EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle);
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static int syscon_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct syscon_platform_data *pdata = dev_get_platdata(dev);
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struct syscon *syscon;
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struct regmap_config syscon_config = syscon_regmap_config;
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struct resource *res;
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void __iomem *base;
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syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
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if (!syscon)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENOENT;
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base = devm_ioremap(dev, res->start, resource_size(res));
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if (!base)
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return -ENOMEM;
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syscon_config.max_register = res->end - res->start - 3;
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if (pdata)
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syscon_config.name = pdata->label;
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syscon->regmap = devm_regmap_init_mmio(dev, base, &syscon_config);
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if (IS_ERR(syscon->regmap)) {
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dev_err(dev, "regmap init failed\n");
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return PTR_ERR(syscon->regmap);
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}
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platform_set_drvdata(pdev, syscon);
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dev_dbg(dev, "regmap %pR registered\n", res);
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return 0;
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}
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static const struct platform_device_id syscon_ids[] = {
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{ "syscon", },
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{ }
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};
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static struct platform_driver syscon_driver = {
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.driver = {
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.name = "syscon",
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},
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.probe = syscon_probe,
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.id_table = syscon_ids,
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};
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static int __init syscon_init(void)
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{
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return platform_driver_register(&syscon_driver);
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}
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postcore_initcall(syscon_init);
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static void __exit syscon_exit(void)
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{
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platform_driver_unregister(&syscon_driver);
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}
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module_exit(syscon_exit);
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MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>");
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MODULE_DESCRIPTION("System Control driver");
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MODULE_LICENSE("GPL v2");
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