Dong Aisheng | 87d6873 | 2012-09-05 10:57:13 +0800 | [diff] [blame] | 1 | /* |
| 2 | * System Control Driver |
| 3 | * |
| 4 | * Copyright (C) 2012 Freescale Semiconductor, Inc. |
| 5 | * Copyright (C) 2012 Linaro Ltd. |
| 6 | * |
| 7 | * Author: Dong Aisheng <dong.aisheng@linaro.org> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/err.h> |
| 16 | #include <linux/io.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/of.h> |
| 19 | #include <linux/of_address.h> |
| 20 | #include <linux/of_platform.h> |
| 21 | #include <linux/platform_device.h> |
| 22 | #include <linux/regmap.h> |
| 23 | |
| 24 | static struct platform_driver syscon_driver; |
| 25 | |
| 26 | struct syscon { |
| 27 | struct device *dev; |
| 28 | void __iomem *base; |
| 29 | struct regmap *regmap; |
| 30 | }; |
| 31 | |
| 32 | static int syscon_match(struct device *dev, void *data) |
| 33 | { |
| 34 | struct syscon *syscon = dev_get_drvdata(dev); |
| 35 | struct device_node *dn = data; |
| 36 | |
| 37 | return (syscon->dev->of_node == dn) ? 1 : 0; |
| 38 | } |
| 39 | |
| 40 | struct regmap *syscon_node_to_regmap(struct device_node *np) |
| 41 | { |
| 42 | struct syscon *syscon; |
| 43 | struct device *dev; |
| 44 | |
| 45 | dev = driver_find_device(&syscon_driver.driver, NULL, np, |
| 46 | syscon_match); |
| 47 | if (!dev) |
| 48 | return ERR_PTR(-EPROBE_DEFER); |
| 49 | |
| 50 | syscon = dev_get_drvdata(dev); |
| 51 | |
| 52 | return syscon->regmap; |
| 53 | } |
| 54 | EXPORT_SYMBOL_GPL(syscon_node_to_regmap); |
| 55 | |
| 56 | struct regmap *syscon_regmap_lookup_by_compatible(const char *s) |
| 57 | { |
| 58 | struct device_node *syscon_np; |
| 59 | struct regmap *regmap; |
| 60 | |
| 61 | syscon_np = of_find_compatible_node(NULL, NULL, s); |
| 62 | if (!syscon_np) |
| 63 | return ERR_PTR(-ENODEV); |
| 64 | |
| 65 | regmap = syscon_node_to_regmap(syscon_np); |
| 66 | of_node_put(syscon_np); |
| 67 | |
| 68 | return regmap; |
| 69 | } |
| 70 | EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_compatible); |
| 71 | |
| 72 | struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np, |
| 73 | const char *property) |
| 74 | { |
| 75 | struct device_node *syscon_np; |
| 76 | struct regmap *regmap; |
| 77 | |
| 78 | syscon_np = of_parse_phandle(np, property, 0); |
| 79 | if (!syscon_np) |
| 80 | return ERR_PTR(-ENODEV); |
| 81 | |
| 82 | regmap = syscon_node_to_regmap(syscon_np); |
| 83 | of_node_put(syscon_np); |
| 84 | |
| 85 | return regmap; |
| 86 | } |
| 87 | EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle); |
| 88 | |
| 89 | static const struct of_device_id of_syscon_match[] = { |
| 90 | { .compatible = "syscon", }, |
| 91 | { }, |
| 92 | }; |
| 93 | |
| 94 | static struct regmap_config syscon_regmap_config = { |
| 95 | .reg_bits = 32, |
| 96 | .val_bits = 32, |
| 97 | .reg_stride = 4, |
| 98 | }; |
| 99 | |
| 100 | static int __devinit syscon_probe(struct platform_device *pdev) |
| 101 | { |
| 102 | struct device *dev = &pdev->dev; |
| 103 | struct device_node *np = dev->of_node; |
| 104 | struct syscon *syscon; |
| 105 | struct resource res; |
| 106 | int ret; |
| 107 | |
| 108 | if (!np) |
| 109 | return -ENOENT; |
| 110 | |
| 111 | syscon = devm_kzalloc(dev, sizeof(struct syscon), |
| 112 | GFP_KERNEL); |
| 113 | if (!syscon) |
| 114 | return -ENOMEM; |
| 115 | |
| 116 | syscon->base = of_iomap(np, 0); |
| 117 | if (!syscon->base) |
| 118 | return -EADDRNOTAVAIL; |
| 119 | |
| 120 | ret = of_address_to_resource(np, 0, &res); |
| 121 | if (ret) |
| 122 | return ret; |
| 123 | |
| 124 | syscon_regmap_config.max_register = res.end - res.start - 3; |
| 125 | syscon->regmap = devm_regmap_init_mmio(dev, syscon->base, |
| 126 | &syscon_regmap_config); |
| 127 | if (IS_ERR(syscon->regmap)) { |
| 128 | dev_err(dev, "regmap init failed\n"); |
| 129 | return PTR_ERR(syscon->regmap); |
| 130 | } |
| 131 | |
| 132 | syscon->dev = dev; |
| 133 | platform_set_drvdata(pdev, syscon); |
| 134 | |
| 135 | dev_info(dev, "syscon regmap start 0x%x end 0x%x registered\n", |
| 136 | res.start, res.end); |
| 137 | |
| 138 | return 0; |
| 139 | } |
| 140 | |
| 141 | static int __devexit syscon_remove(struct platform_device *pdev) |
| 142 | { |
| 143 | struct syscon *syscon; |
| 144 | |
| 145 | syscon = platform_get_drvdata(pdev); |
| 146 | iounmap(syscon->base); |
| 147 | platform_set_drvdata(pdev, NULL); |
| 148 | |
| 149 | return 0; |
| 150 | } |
| 151 | |
| 152 | static struct platform_driver syscon_driver = { |
| 153 | .driver = { |
| 154 | .name = "syscon", |
| 155 | .owner = THIS_MODULE, |
| 156 | .of_match_table = of_syscon_match, |
| 157 | }, |
| 158 | .probe = syscon_probe, |
Bill Pemberton | 8444921 | 2012-11-19 13:20:24 -0500 | [diff] [blame^] | 159 | .remove = syscon_remove, |
Dong Aisheng | 87d6873 | 2012-09-05 10:57:13 +0800 | [diff] [blame] | 160 | }; |
| 161 | |
| 162 | static int __init syscon_init(void) |
| 163 | { |
| 164 | return platform_driver_register(&syscon_driver); |
| 165 | } |
| 166 | postcore_initcall(syscon_init); |
| 167 | |
| 168 | static void __exit syscon_exit(void) |
| 169 | { |
| 170 | platform_driver_unregister(&syscon_driver); |
| 171 | } |
| 172 | module_exit(syscon_exit); |
| 173 | |
| 174 | MODULE_AUTHOR("Dong Aisheng <dong.aisheng@linaro.org>"); |
| 175 | MODULE_DESCRIPTION("System Control driver"); |
| 176 | MODULE_LICENSE("GPL v2"); |