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 1.2 2005/03/14 20:33:19 bjd 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 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 struct resource *area; 49 struct platdata_mtd_ram *pdata; 50 }; 51 52 /* to_platram_info() 53 * 54 * device private data to struct platram_info conversion 55 */ 56 57 static inline struct platram_info *to_platram_info(struct device *dev) 58 { 59 return (struct platram_info *)dev_get_drvdata(dev); 60 } 61 62 /* platram_setrw 63 * 64 * call the platform device's set rw/ro control 65 * 66 * to = 0 => read-only 67 * = 1 => read-write 68 */ 69 70 static inline void platram_setrw(struct platram_info *info, int to) 71 { 72 if (info->pdata == NULL) 73 return; 74 75 if (info->pdata->set_rw != NULL) 76 (info->pdata->set_rw)(info->dev, to); 77 } 78 79 /* platram_remove 80 * 81 * called to remove the device from the driver's control 82 */ 83 84 static int platram_remove(struct device *dev) 85 { 86 struct platram_info *info = to_platram_info(dev); 87 88 dev_set_drvdata(dev, NULL); 89 90 dev_dbg(dev, "removing device\n"); 91 92 if (info == NULL) 93 return 0; 94 95 if (info->mtd) { 96 #ifdef CONFIG_MTD_PARTITIONS 97 if (info->partitions) { 98 del_mtd_partitions(info->mtd); 99 kfree(info->partitions); 100 } 101 #endif 102 del_mtd_device(info->mtd); 103 map_destroy(info->mtd); 104 } 105 106 /* ensure ram is left read-only */ 107 108 platram_setrw(info, PLATRAM_RO); 109 110 /* release resources */ 111 112 if (info->area) { 113 release_resource(info->area); 114 kfree(info->area); 115 } 116 117 if (info->map.virt != NULL) 118 iounmap(info->map.virt); 119 120 kfree(info); 121 122 return 0; 123 } 124 125 /* platram_probe 126 * 127 * called from device drive system when a device matching our 128 * driver is found. 129 */ 130 131 static int platram_probe(struct device *dev) 132 { 133 struct platform_device *pd = to_platform_device(dev); 134 struct platdata_mtd_ram *pdata; 135 struct platram_info *info; 136 struct resource *res; 137 int err = 0; 138 139 dev_dbg(dev, "probe entered\n"); 140 141 if (dev->platform_data == NULL) { 142 dev_err(dev, "no platform data supplied\n"); 143 err = -ENOENT; 144 goto exit_error; 145 } 146 147 pdata = dev->platform_data; 148 149 info = kmalloc(sizeof(*info), GFP_KERNEL); 150 if (info == NULL) { 151 dev_err(dev, "no memory for flash info\n"); 152 err = -ENOMEM; 153 goto exit_error; 154 } 155 156 memzero(info, sizeof(*info)); 157 dev_set_drvdata(dev, info); 158 159 info->dev = dev; 160 info->pdata = pdata; 161 162 /* get the resource for the memory mapping */ 163 164 res = platform_get_resource(pd, IORESOURCE_MEM, 0); 165 166 if (res == NULL) { 167 dev_err(dev, "no memory resource specified\n"); 168 err = -ENOENT; 169 goto exit_free; 170 } 171 172 dev_dbg(dev, "got platform resource %p (0x%lx)\n", res, res->start); 173 174 /* setup map parameters */ 175 176 info->map.phys = res->start; 177 info->map.size = (res->end - res->start) + 1; 178 info->map.name = pdata->mapname != NULL ? pdata->mapname : pd->name; 179 info->map.bankwidth = pdata->bankwidth; 180 181 /* register our usage of the memory area */ 182 183 info->area = request_mem_region(res->start, info->map.size, pd->name); 184 if (info->area == NULL) { 185 dev_err(dev, "failed to request memory region\n"); 186 err = -EIO; 187 goto exit_free; 188 } 189 190 /* remap the memory area */ 191 192 info->map.virt = ioremap(res->start, info->map.size); 193 dev_dbg(dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); 194 195 if (info->map.virt == NULL) { 196 dev_err(dev, "failed to ioremap() region\n"); 197 err = -EIO; 198 goto exit_free; 199 } 200 201 simple_map_init(&info->map); 202 203 dev_dbg(dev, "initialised map, probing for mtd\n"); 204 205 /* probe for the right mtd map driver */ 206 207 info->mtd = do_map_probe("map_ram" , &info->map); 208 if (info->mtd == NULL) { 209 dev_err(dev, "failed to probe for map_ram\n"); 210 err = -ENOMEM; 211 goto exit_free; 212 } 213 214 info->mtd->owner = THIS_MODULE; 215 216 platram_setrw(info, PLATRAM_RW); 217 218 /* check to see if there are any available partitions, or wether 219 * to add this device whole */ 220 221 #ifdef CONFIG_MTD_PARTITIONS 222 if (pdata->nr_partitions > 0) { 223 const char **probes = { NULL }; 224 225 if (pdata->probes) 226 probes = (const char **)pdata->probes; 227 228 err = parse_mtd_partitions(info->mtd, probes, 229 &info->partitions, 0); 230 if (err > 0) { 231 err = add_mtd_partitions(info->mtd, info->partitions, 232 err); 233 } 234 } 235 #endif /* CONFIG_MTD_PARTITIONS */ 236 237 if (add_mtd_device(info->mtd)) { 238 dev_err(dev, "add_mtd_device() failed\n"); 239 err = -ENOMEM; 240 } 241 242 dev_info(dev, "registered mtd device\n"); 243 return err; 244 245 exit_free: 246 platram_remove(dev); 247 exit_error: 248 return err; 249 } 250 251 /* device driver info */ 252 253 static struct device_driver platram_driver = { 254 .name = "mtd-ram", 255 .bus = &platform_bus_type, 256 .probe = platram_probe, 257 .remove = platram_remove, 258 }; 259 260 /* module init/exit */ 261 262 static int __init platram_init(void) 263 { 264 printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n"); 265 return driver_register(&platram_driver); 266 } 267 268 static void __exit platram_exit(void) 269 { 270 driver_unregister(&platram_driver); 271 } 272 273 module_init(platram_init); 274 module_exit(platram_exit); 275 276 MODULE_LICENSE("GPL"); 277 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 278 MODULE_DESCRIPTION("MTD platform RAM map driver"); 279