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1// SPDX-License-Identifier: GPL-2.0-or-later2/* drivers/mtd/maps/plat-ram.c3 *4 * (c) 2004-2005 Simtec Electronics5 * http://www.simtec.co.uk/products/SWLINUX/6 * Ben Dooks <ben@simtec.co.uk>7 *8 * Generic platform device based RAM map9*/10 11#include <linux/module.h>12#include <linux/types.h>13#include <linux/kernel.h>14#include <linux/string.h>15#include <linux/ioport.h>16#include <linux/device.h>17#include <linux/slab.h>18#include <linux/platform_device.h>19 20#include <linux/mtd/mtd.h>21#include <linux/mtd/map.h>22#include <linux/mtd/partitions.h>23#include <linux/mtd/plat-ram.h>24 25#include <asm/io.h>26 27/* private structure for each mtd platform ram device created */28 29struct platram_info {30 struct device *dev;31 struct mtd_info *mtd;32 struct map_info map;33 struct platdata_mtd_ram *pdata;34};35 36/* to_platram_info()37 *38 * device private data to struct platram_info conversion39*/40 41static inline struct platram_info *to_platram_info(struct platform_device *dev)42{43 return platform_get_drvdata(dev);44}45 46/* platram_setrw47 *48 * call the platform device's set rw/ro control49 *50 * to = 0 => read-only51 * = 1 => read-write52*/53 54static inline void platram_setrw(struct platram_info *info, int to)55{56 if (info->pdata == NULL)57 return;58 59 if (info->pdata->set_rw != NULL)60 (info->pdata->set_rw)(info->dev, to);61}62 63/* platram_remove64 *65 * called to remove the device from the driver's control66*/67 68static void platram_remove(struct platform_device *pdev)69{70 struct platram_info *info = to_platram_info(pdev);71 72 dev_dbg(&pdev->dev, "removing device\n");73 74 if (info == NULL)75 return;76 77 if (info->mtd) {78 mtd_device_unregister(info->mtd);79 map_destroy(info->mtd);80 }81 82 /* ensure ram is left read-only */83 84 platram_setrw(info, PLATRAM_RO);85 86 kfree(info);87}88 89/* platram_probe90 *91 * called from device drive system when a device matching our92 * driver is found.93*/94 95static int platram_probe(struct platform_device *pdev)96{97 struct platdata_mtd_ram *pdata;98 struct platram_info *info;99 struct resource *res;100 int err = 0;101 102 dev_dbg(&pdev->dev, "probe entered\n");103 104 if (dev_get_platdata(&pdev->dev) == NULL) {105 dev_err(&pdev->dev, "no platform data supplied\n");106 err = -ENOENT;107 goto exit_error;108 }109 110 pdata = dev_get_platdata(&pdev->dev);111 112 info = kzalloc(sizeof(*info), GFP_KERNEL);113 if (info == NULL) {114 err = -ENOMEM;115 goto exit_error;116 }117 118 platform_set_drvdata(pdev, info);119 120 info->dev = &pdev->dev;121 info->pdata = pdata;122 123 /* get the resource for the memory mapping */124 info->map.virt = devm_platform_get_and_ioremap_resource(pdev, 0, &res);125 if (IS_ERR(info->map.virt)) {126 err = PTR_ERR(info->map.virt);127 goto exit_free;128 }129 130 dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res,131 (unsigned long long)res->start);132 133 /* setup map parameters */134 135 info->map.phys = res->start;136 info->map.size = resource_size(res);137 info->map.name = pdata->mapname != NULL ?138 (char *)pdata->mapname : (char *)pdev->name;139 info->map.bankwidth = pdata->bankwidth;140 141 dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);142 143 simple_map_init(&info->map);144 145 dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");146 147 /* probe for the right mtd map driver148 * supplied by the platform_data struct */149 150 if (pdata->map_probes) {151 const char * const *map_probes = pdata->map_probes;152 153 for ( ; !info->mtd && *map_probes; map_probes++)154 info->mtd = do_map_probe(*map_probes , &info->map);155 }156 /* fallback to map_ram */157 else158 info->mtd = do_map_probe("map_ram", &info->map);159 160 if (info->mtd == NULL) {161 dev_err(&pdev->dev, "failed to probe for map_ram\n");162 err = -ENOMEM;163 goto exit_free;164 }165 166 info->mtd->dev.parent = &pdev->dev;167 168 platram_setrw(info, PLATRAM_RW);169 170 /* check to see if there are any available partitions, or whether171 * to add this device whole */172 173 err = mtd_device_parse_register(info->mtd, pdata->probes, NULL,174 pdata->partitions,175 pdata->nr_partitions);176 if (err) {177 dev_err(&pdev->dev, "failed to register mtd device\n");178 goto exit_free;179 }180 181 dev_info(&pdev->dev, "registered mtd device\n");182 183 if (pdata->nr_partitions) {184 /* add the whole device. */185 err = mtd_device_register(info->mtd, NULL, 0);186 if (err) {187 dev_err(&pdev->dev,188 "failed to register the entire device\n");189 goto exit_free;190 }191 }192 193 return 0;194 195 exit_free:196 platram_remove(pdev);197 exit_error:198 return err;199}200 201/* device driver info */202 203/* work with hotplug and coldplug */204MODULE_ALIAS("platform:mtd-ram");205 206static struct platform_driver platram_driver = {207 .probe = platram_probe,208 .remove_new = platram_remove,209 .driver = {210 .name = "mtd-ram",211 },212};213 214module_platform_driver(platram_driver);215 216MODULE_LICENSE("GPL");217MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");218MODULE_DESCRIPTION("MTD platform RAM map driver");219