OpenWrt – Blame information for rev 1
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Rev | Author | Line No. | Line |
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1 | office | 1 | From e53f712d8eac71f54399b61038ccf87d2cee99d7 Mon Sep 17 00:00:00 2001 |
2 | From: Bernhard Frauendienst <kernel@nospam.obeliks.de> |
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3 | Date: Sat, 25 Aug 2018 12:35:22 +0200 |
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4 | Subject: [PATCH 497/497] mtd: mtdconcat: add dt driver for concat devices |
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5 | |||
6 | Some mtd drivers like physmap variants have support for concatenating |
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7 | multiple mtd devices, but there is no generic way to define such a |
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8 | concat device from within the device tree. |
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9 | |||
10 | This is useful for some SoC boards that use multiple flash chips as |
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11 | memory banks of a single mtd device, with partitions spanning chip |
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12 | borders. |
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13 | |||
14 | This commit adds a driver for creating virtual mtd-concat devices. They |
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15 | must have a compatible = "mtd-concat" line, and define a list of devices |
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16 | to concat in the 'devices' property, for example: |
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17 | |||
18 | flash { |
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19 | compatible = "mtd-concat"; |
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20 | |||
21 | devices = <&flash0 &flash1>; |
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22 | |||
23 | partitions { |
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24 | ... |
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25 | }; |
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26 | }; |
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27 | |||
28 | The driver is added to the very end of the mtd Makefile to increase the |
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29 | likelyhood of all child devices already being loaded at the time of |
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30 | probing, preventing unnecessary deferred probes. |
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31 | |||
32 | Signed-off-by: Bernhard Frauendienst <kernel@nospam.obeliks.de> |
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33 | --- |
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34 | drivers/mtd/Kconfig | 2 + |
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35 | drivers/mtd/Makefile | 3 + |
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36 | drivers/mtd/composite/Kconfig | 12 +++ |
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37 | drivers/mtd/composite/Makefile | 6 ++ |
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38 | drivers/mtd/composite/virt_concat.c | 128 ++++++++++++++++++++++++++++ |
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39 | 5 files changed, 151 insertions(+) |
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40 | create mode 100644 drivers/mtd/composite/Kconfig |
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41 | create mode 100644 drivers/mtd/composite/Makefile |
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42 | create mode 100644 drivers/mtd/composite/virt_concat.c |
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43 | |||
44 | --- a/drivers/mtd/Kconfig |
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45 | +++ b/drivers/mtd/Kconfig |
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46 | @@ -377,4 +377,6 @@ source "drivers/mtd/spi-nor/Kconfig" |
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47 | |||
48 | source "drivers/mtd/ubi/Kconfig" |
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49 | |||
50 | +source "drivers/mtd/composite/Kconfig" |
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51 | + |
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52 | endif # MTD |
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53 | --- a/drivers/mtd/Makefile |
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54 | +++ b/drivers/mtd/Makefile |
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55 | @@ -39,3 +39,6 @@ obj-y += chips/ lpddr/ maps/ devices/ n |
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56 | |||
57 | obj-$(CONFIG_MTD_SPI_NOR) += spi-nor/ |
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58 | obj-$(CONFIG_MTD_UBI) += ubi/ |
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59 | + |
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60 | +# Composite drivers must be loaded last |
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61 | +obj-y += composite/ |
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62 | --- /dev/null |
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63 | +++ b/drivers/mtd/composite/Kconfig |
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64 | @@ -0,0 +1,12 @@ |
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65 | +menu "Composite MTD device drivers" |
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66 | + depends on MTD!=n |
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67 | + |
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68 | +config MTD_VIRT_CONCAT |
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69 | + tristate "Virtual concat MTD device" |
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70 | + help |
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71 | + This driver allows creation of a virtual MTD concat device, which |
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72 | + concatenates multiple underlying MTD devices to a single device. |
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73 | + This is required by some SoC boards where multiple memory banks are |
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74 | + used as one device with partitions spanning across device boundaries. |
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75 | + |
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76 | +endmenu |
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77 | --- /dev/null |
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78 | +++ b/drivers/mtd/composite/Makefile |
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79 | @@ -0,0 +1,6 @@ |
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80 | +# SPDX-License-Identifier: GPL-2.0 |
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81 | +# |
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82 | +# linux/drivers/mtd/composite/Makefile |
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83 | +# |
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84 | + |
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85 | +obj-$(CONFIG_MTD_VIRT_CONCAT) += virt_concat.o |
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86 | --- /dev/null |
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87 | +++ b/drivers/mtd/composite/virt_concat.c |
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88 | @@ -0,0 +1,128 @@ |
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89 | +// SPDX-License-Identifier: GPL-2.0+ |
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90 | +/* |
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91 | + * Virtual concat MTD device driver |
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92 | + * |
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93 | + * Copyright (C) 2018 Bernhard Frauendienst |
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94 | + * Author: Bernhard Frauendienst, kernel@nospam.obeliks.de |
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95 | + */ |
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96 | + |
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97 | +#include <linux/module.h> |
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98 | +#include <linux/device.h> |
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99 | +#include <linux/mtd/concat.h> |
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100 | +#include <linux/mtd/mtd.h> |
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101 | +#include <linux/mtd/partitions.h> |
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102 | +#include <linux/of.h> |
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103 | +#include <linux/of_platform.h> |
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104 | +#include <linux/slab.h> |
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105 | + |
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106 | +/* |
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107 | + * struct of_virt_concat - platform device driver data. |
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108 | + * @cmtd the final mtd_concat device |
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109 | + * @num_devices the number of devices in @devices |
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110 | + * @devices points to an array of devices already loaded |
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111 | + */ |
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112 | +struct of_virt_concat { |
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113 | + struct mtd_info *cmtd; |
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114 | + int num_devices; |
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115 | + struct mtd_info **devices; |
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116 | +}; |
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117 | + |
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118 | +static int virt_concat_remove(struct platform_device *pdev) |
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119 | +{ |
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120 | + struct of_virt_concat *info; |
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121 | + int i; |
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122 | + |
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123 | + info = platform_get_drvdata(pdev); |
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124 | + if (!info) |
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125 | + return 0; |
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126 | + |
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127 | + // unset data for when this is called after a probe error |
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128 | + platform_set_drvdata(pdev, NULL); |
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129 | + |
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130 | + if (info->cmtd) { |
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131 | + mtd_device_unregister(info->cmtd); |
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132 | + mtd_concat_destroy(info->cmtd); |
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133 | + } |
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134 | + |
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135 | + if (info->devices) { |
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136 | + for (i = 0; i < info->num_devices; i++) |
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137 | + put_mtd_device(info->devices[i]); |
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138 | + } |
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139 | + |
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140 | + return 0; |
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141 | +} |
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142 | + |
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143 | +static int virt_concat_probe(struct platform_device *pdev) |
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144 | +{ |
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145 | + struct device_node *node = pdev->dev.of_node; |
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146 | + struct of_phandle_iterator it; |
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147 | + struct of_virt_concat *info; |
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148 | + struct mtd_info *mtd; |
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149 | + int err = 0, count; |
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150 | + |
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151 | + count = of_count_phandle_with_args(node, "devices", NULL); |
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152 | + if (count <= 0) |
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153 | + return -EINVAL; |
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154 | + |
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155 | + info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL); |
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156 | + if (!info) |
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157 | + return -ENOMEM; |
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158 | + info->devices = devm_kcalloc(&pdev->dev, count, |
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159 | + sizeof(*(info->devices)), GFP_KERNEL); |
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160 | + if (!info->devices) { |
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161 | + err = -ENOMEM; |
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162 | + goto err_remove; |
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163 | + } |
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164 | + |
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165 | + platform_set_drvdata(pdev, info); |
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166 | + |
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167 | + of_for_each_phandle(&it, err, node, "devices", NULL, 0) { |
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168 | + mtd = get_mtd_device_by_node(it.node); |
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169 | + if (IS_ERR(mtd)) { |
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170 | + of_node_put(it.node); |
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171 | + err = -EPROBE_DEFER; |
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172 | + goto err_remove; |
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173 | + } |
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174 | + |
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175 | + info->devices[info->num_devices++] = mtd; |
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176 | + } |
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177 | + |
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178 | + info->cmtd = mtd_concat_create(info->devices, info->num_devices, |
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179 | + dev_name(&pdev->dev)); |
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180 | + if (!info->cmtd) { |
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181 | + err = -ENXIO; |
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182 | + goto err_remove; |
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183 | + } |
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184 | + |
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185 | + info->cmtd->dev.parent = &pdev->dev; |
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186 | + mtd_set_of_node(info->cmtd, node); |
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187 | + mtd_device_register(info->cmtd, NULL, 0); |
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188 | + |
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189 | + return 0; |
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190 | + |
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191 | +err_remove: |
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192 | + virt_concat_remove(pdev); |
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193 | + |
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194 | + return err; |
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195 | +} |
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196 | + |
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197 | +static const struct of_device_id virt_concat_of_match[] = { |
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198 | + { .compatible = "mtd-concat", }, |
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199 | + { /* sentinel */ } |
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200 | +}; |
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201 | +MODULE_DEVICE_TABLE(of, virt_concat_of_match); |
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202 | + |
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203 | +static struct platform_driver virt_concat_driver = { |
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204 | + .probe = virt_concat_probe, |
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205 | + .remove = virt_concat_remove, |
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206 | + .driver = { |
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207 | + .name = "virt-mtdconcat", |
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208 | + .of_match_table = virt_concat_of_match, |
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209 | + }, |
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210 | +}; |
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211 | + |
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212 | +module_platform_driver(virt_concat_driver); |
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213 | + |
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214 | +MODULE_LICENSE("GPL v2"); |
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215 | +MODULE_AUTHOR("Bernhard Frauendienst <kernel@nospam.obeliks.de>"); |
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216 | +MODULE_DESCRIPTION("Virtual concat MTD device driver"); |