1 /* drivers/mtd/maps/plat-ram.c 2 * 3 * (c) 2004-2005 Simtec Electronics 4 * http://www.simtec.co.uk/products/SWLINUX/ 5 * Ben Dooks <ben@simtec.co.uk> 6 * 7 * Generic platfrom device based RAM map 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 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22 */ 23 24 #include <linux/module.h> 25 #include <linux/types.h> 26 #include <linux/init.h> 27 #include <linux/kernel.h> 28 #include <linux/string.h> 29 #include <linux/ioport.h> 30 #include <linux/device.h> 31 #include <linux/slab.h> 32 #include <linux/platform_device.h> 33 34 #include <linux/mtd/mtd.h> 35 #include <linux/mtd/map.h> 36 #include <linux/mtd/partitions.h> 37 #include <linux/mtd/plat-ram.h> 38 39 #include <asm/io.h> 40 41 /* private structure for each mtd platform ram device created */ 42 43 struct platram_info { 44 struct device *dev; 45 struct mtd_info *mtd; 46 struct map_info map; 47 struct mtd_partition *partitions; 48 bool free_partitions; 49 struct resource *area; 50 struct platdata_mtd_ram *pdata; 51 }; 52 53 /* to_platram_info() 54 * 55 * device private data to struct platram_info conversion 56 */ 57 58 static inline struct platram_info *to_platram_info(struct platform_device *dev) 59 { 60 return (struct platram_info *)platform_get_drvdata(dev); 61 } 62 63 /* platram_setrw 64 * 65 * call the platform device's set rw/ro control 66 * 67 * to = 0 => read-only 68 * = 1 => read-write 69 */ 70 71 static inline void platram_setrw(struct platram_info *info, int to) 72 { 73 if (info->pdata == NULL) 74 return; 75 76 if (info->pdata->set_rw != NULL) 77 (info->pdata->set_rw)(info->dev, to); 78 } 79 80 /* platram_remove 81 * 82 * called to remove the device from the driver's control 83 */ 84 85 static int platram_remove(struct platform_device *pdev) 86 { 87 struct platram_info *info = to_platram_info(pdev); 88 89 platform_set_drvdata(pdev, NULL); 90 91 dev_dbg(&pdev->dev, "removing device\n"); 92 93 if (info == NULL) 94 return 0; 95 96 if (info->mtd) { 97 #ifdef CONFIG_MTD_PARTITIONS 98 if (info->partitions) { 99 del_mtd_partitions(info->mtd); 100 if (info->free_partitions) 101 kfree(info->partitions); 102 } 103 #endif 104 del_mtd_device(info->mtd); 105 map_destroy(info->mtd); 106 } 107 108 /* ensure ram is left read-only */ 109 110 platram_setrw(info, PLATRAM_RO); 111 112 /* release resources */ 113 114 if (info->area) { 115 release_resource(info->area); 116 kfree(info->area); 117 } 118 119 if (info->map.virt != NULL) 120 iounmap(info->map.virt); 121 122 kfree(info); 123 124 return 0; 125 } 126 127 /* platram_probe 128 * 129 * called from device drive system when a device matching our 130 * driver is found. 131 */ 132 133 static int platram_probe(struct platform_device *pdev) 134 { 135 struct platdata_mtd_ram *pdata; 136 struct platram_info *info; 137 struct resource *res; 138 int err = 0; 139 140 dev_dbg(&pdev->dev, "probe entered\n"); 141 142 if (pdev->dev.platform_data == NULL) { 143 dev_err(&pdev->dev, "no platform data supplied\n"); 144 err = -ENOENT; 145 goto exit_error; 146 } 147 148 pdata = pdev->dev.platform_data; 149 150 info = kzalloc(sizeof(*info), GFP_KERNEL); 151 if (info == NULL) { 152 dev_err(&pdev->dev, "no memory for flash info\n"); 153 err = -ENOMEM; 154 goto exit_error; 155 } 156 157 platform_set_drvdata(pdev, info); 158 159 info->dev = &pdev->dev; 160 info->pdata = pdata; 161 162 /* get the resource for the memory mapping */ 163 164 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 165 166 if (res == NULL) { 167 dev_err(&pdev->dev, "no memory resource specified\n"); 168 err = -ENOENT; 169 goto exit_free; 170 } 171 172 dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res, 173 (unsigned long long)res->start); 174 175 /* setup map parameters */ 176 177 info->map.phys = res->start; 178 info->map.size = resource_size(res); 179 info->map.name = pdata->mapname != NULL ? 180 (char *)pdata->mapname : (char *)pdev->name; 181 info->map.bankwidth = pdata->bankwidth; 182 183 /* register our usage of the memory area */ 184 185 info->area = request_mem_region(res->start, info->map.size, pdev->name); 186 if (info->area == NULL) { 187 dev_err(&pdev->dev, "failed to request memory region\n"); 188 err = -EIO; 189 goto exit_free; 190 } 191 192 /* remap the memory area */ 193 194 info->map.virt = ioremap(res->start, info->map.size); 195 dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); 196 197 if (info->map.virt == NULL) { 198 dev_err(&pdev->dev, "failed to ioremap() region\n"); 199 err = -EIO; 200 goto exit_free; 201 } 202 203 simple_map_init(&info->map); 204 205 dev_dbg(&pdev->dev, "initialised map, probing for mtd\n"); 206 207 /* probe for the right mtd map driver 208 * supplied by the platform_data struct */ 209 210 if (pdata->map_probes) { 211 const char **map_probes = pdata->map_probes; 212 213 for ( ; !info->mtd && *map_probes; map_probes++) 214 info->mtd = do_map_probe(*map_probes , &info->map); 215 } 216 /* fallback to map_ram */ 217 else 218 info->mtd = do_map_probe("map_ram", &info->map); 219 220 if (info->mtd == NULL) { 221 dev_err(&pdev->dev, "failed to probe for map_ram\n"); 222 err = -ENOMEM; 223 goto exit_free; 224 } 225 226 info->mtd->owner = THIS_MODULE; 227 info->mtd->dev.parent = &pdev->dev; 228 229 platram_setrw(info, PLATRAM_RW); 230 231 /* check to see if there are any available partitions, or wether 232 * to add this device whole */ 233 234 #ifdef CONFIG_MTD_PARTITIONS 235 if (!pdata->nr_partitions) { 236 /* try to probe using the supplied probe type */ 237 if (pdata->probes) { 238 err = parse_mtd_partitions(info->mtd, pdata->probes, 239 &info->partitions, 0); 240 info->free_partitions = 1; 241 if (err > 0) 242 err = add_mtd_partitions(info->mtd, 243 info->partitions, err); 244 } 245 } 246 /* use the static mapping */ 247 else 248 err = add_mtd_partitions(info->mtd, pdata->partitions, 249 pdata->nr_partitions); 250 #endif /* CONFIG_MTD_PARTITIONS */ 251 252 if (add_mtd_device(info->mtd)) { 253 dev_err(&pdev->dev, "add_mtd_device() failed\n"); 254 err = -ENOMEM; 255 } 256 257 if (!err) 258 dev_info(&pdev->dev, "registered mtd device\n"); 259 260 return err; 261 262 exit_free: 263 platram_remove(pdev); 264 exit_error: 265 return err; 266 } 267 268 /* device driver info */ 269 270 /* work with hotplug and coldplug */ 271 MODULE_ALIAS("platform:mtd-ram"); 272 273 static struct platform_driver platram_driver = { 274 .probe = platram_probe, 275 .remove = platram_remove, 276 .driver = { 277 .name = "mtd-ram", 278 .owner = THIS_MODULE, 279 }, 280 }; 281 282 /* module init/exit */ 283 284 static int __init platram_init(void) 285 { 286 printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n"); 287 return platform_driver_register(&platram_driver); 288 } 289 290 static void __exit platram_exit(void) 291 { 292 platform_driver_unregister(&platram_driver); 293 } 294 295 module_init(platram_init); 296 module_exit(platram_exit); 297 298 MODULE_LICENSE("GPL"); 299 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 300 MODULE_DESCRIPTION("MTD platform RAM map driver"); 301