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 * $Id: plat-ram.c,v 1.7 2005/11/07 11:14:28 gleixner Exp $ 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 24 */ 25 26 #include <linux/module.h> 27 #include <linux/types.h> 28 #include <linux/init.h> 29 #include <linux/kernel.h> 30 #include <linux/string.h> 31 #include <linux/ioport.h> 32 #include <linux/device.h> 33 #include <linux/slab.h> 34 #include <linux/platform_device.h> 35 36 #include <linux/mtd/mtd.h> 37 #include <linux/mtd/map.h> 38 #include <linux/mtd/partitions.h> 39 #include <linux/mtd/plat-ram.h> 40 41 #include <asm/io.h> 42 43 /* private structure for each mtd platform ram device created */ 44 45 struct platram_info { 46 struct device *dev; 47 struct mtd_info *mtd; 48 struct map_info map; 49 struct mtd_partition *partitions; 50 bool free_partitions; 51 struct resource *area; 52 struct platdata_mtd_ram *pdata; 53 }; 54 55 /* to_platram_info() 56 * 57 * device private data to struct platram_info conversion 58 */ 59 60 static inline struct platram_info *to_platram_info(struct platform_device *dev) 61 { 62 return (struct platram_info *)platform_get_drvdata(dev); 63 } 64 65 /* platram_setrw 66 * 67 * call the platform device's set rw/ro control 68 * 69 * to = 0 => read-only 70 * = 1 => read-write 71 */ 72 73 static inline void platram_setrw(struct platram_info *info, int to) 74 { 75 if (info->pdata == NULL) 76 return; 77 78 if (info->pdata->set_rw != NULL) 79 (info->pdata->set_rw)(info->dev, to); 80 } 81 82 /* platram_remove 83 * 84 * called to remove the device from the driver's control 85 */ 86 87 static int platram_remove(struct platform_device *pdev) 88 { 89 struct platram_info *info = to_platram_info(pdev); 90 91 platform_set_drvdata(pdev, NULL); 92 93 dev_dbg(&pdev->dev, "removing device\n"); 94 95 if (info == NULL) 96 return 0; 97 98 if (info->mtd) { 99 #ifdef CONFIG_MTD_PARTITIONS 100 if (info->partitions) { 101 del_mtd_partitions(info->mtd); 102 if (info->free_partitions) 103 kfree(info->partitions); 104 } 105 #endif 106 del_mtd_device(info->mtd); 107 map_destroy(info->mtd); 108 } 109 110 /* ensure ram is left read-only */ 111 112 platram_setrw(info, PLATRAM_RO); 113 114 /* release resources */ 115 116 if (info->area) { 117 release_resource(info->area); 118 kfree(info->area); 119 } 120 121 if (info->map.virt != NULL) 122 iounmap(info->map.virt); 123 124 kfree(info); 125 126 return 0; 127 } 128 129 /* platram_probe 130 * 131 * called from device drive system when a device matching our 132 * driver is found. 133 */ 134 135 static int platram_probe(struct platform_device *pdev) 136 { 137 struct platdata_mtd_ram *pdata; 138 struct platram_info *info; 139 struct resource *res; 140 int err = 0; 141 142 dev_dbg(&pdev->dev, "probe entered\n"); 143 144 if (pdev->dev.platform_data == NULL) { 145 dev_err(&pdev->dev, "no platform data supplied\n"); 146 err = -ENOENT; 147 goto exit_error; 148 } 149 150 pdata = pdev->dev.platform_data; 151 152 info = kzalloc(sizeof(*info), GFP_KERNEL); 153 if (info == NULL) { 154 dev_err(&pdev->dev, "no memory for flash info\n"); 155 err = -ENOMEM; 156 goto exit_error; 157 } 158 159 platform_set_drvdata(pdev, info); 160 161 info->dev = &pdev->dev; 162 info->pdata = pdata; 163 164 /* get the resource for the memory mapping */ 165 166 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 167 168 if (res == NULL) { 169 dev_err(&pdev->dev, "no memory resource specified\n"); 170 err = -ENOENT; 171 goto exit_free; 172 } 173 174 dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res, 175 (unsigned long long)res->start); 176 177 /* setup map parameters */ 178 179 info->map.phys = res->start; 180 info->map.size = (res->end - res->start) + 1; 181 info->map.name = pdata->mapname != NULL ? 182 (char *)pdata->mapname : (char *)pdev->name; 183 info->map.bankwidth = pdata->bankwidth; 184 185 /* register our usage of the memory area */ 186 187 info->area = request_mem_region(res->start, info->map.size, pdev->name); 188 if (info->area == NULL) { 189 dev_err(&pdev->dev, "failed to request memory region\n"); 190 err = -EIO; 191 goto exit_free; 192 } 193 194 /* remap the memory area */ 195 196 info->map.virt = ioremap(res->start, info->map.size); 197 dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); 198 199 if (info->map.virt == NULL) { 200 dev_err(&pdev->dev, "failed to ioremap() region\n"); 201 err = -EIO; 202 goto exit_free; 203 } 204 205 simple_map_init(&info->map); 206 207 dev_dbg(&pdev->dev, "initialised map, probing for mtd\n"); 208 209 /* probe for the right mtd map driver 210 * supplied by the platform_data struct */ 211 212 if (pdata->map_probes != 0) { 213 const char **map_probes = pdata->map_probes; 214 215 for ( ; !info->mtd && *map_probes; map_probes++) 216 info->mtd = do_map_probe(*map_probes , &info->map); 217 } 218 /* fallback to map_ram */ 219 else 220 info->mtd = do_map_probe("map_ram", &info->map); 221 222 if (info->mtd == NULL) { 223 dev_err(&pdev->dev, "failed to probe for map_ram\n"); 224 err = -ENOMEM; 225 goto exit_free; 226 } 227 228 info->mtd->owner = THIS_MODULE; 229 230 platram_setrw(info, PLATRAM_RW); 231 232 /* check to see if there are any available partitions, or wether 233 * to add this device whole */ 234 235 #ifdef CONFIG_MTD_PARTITIONS 236 if (!pdata->nr_partitions) { 237 /* try to probe using the supplied probe type */ 238 if (pdata->probes) { 239 err = parse_mtd_partitions(info->mtd, pdata->probes, 240 &info->partitions, 0); 241 info->free_partitions = 1; 242 if (err > 0) 243 err = add_mtd_partitions(info->mtd, 244 info->partitions, err); 245 } 246 } 247 /* use the static mapping */ 248 else 249 err = add_mtd_partitions(info->mtd, pdata->partitions, 250 pdata->nr_partitions); 251 #endif /* CONFIG_MTD_PARTITIONS */ 252 253 if (add_mtd_device(info->mtd)) { 254 dev_err(&pdev->dev, "add_mtd_device() failed\n"); 255 err = -ENOMEM; 256 } 257 258 if (!err) 259 dev_info(&pdev->dev, "registered mtd device\n"); 260 261 return err; 262 263 exit_free: 264 platram_remove(pdev); 265 exit_error: 266 return err; 267 } 268 269 /* device driver info */ 270 271 /* work with hotplug and coldplug */ 272 MODULE_ALIAS("platform:mtd-ram"); 273 274 static struct platform_driver platram_driver = { 275 .probe = platram_probe, 276 .remove = platram_remove, 277 .driver = { 278 .name = "mtd-ram", 279 .owner = THIS_MODULE, 280 }, 281 }; 282 283 /* module init/exit */ 284 285 static int __init platram_init(void) 286 { 287 printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n"); 288 return platform_driver_register(&platram_driver); 289 } 290 291 static void __exit platram_exit(void) 292 { 293 platform_driver_unregister(&platram_driver); 294 } 295 296 module_init(platram_init); 297 module_exit(platram_exit); 298 299 MODULE_LICENSE("GPL"); 300 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 301 MODULE_DESCRIPTION("MTD platform RAM map driver"); 302