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 1.3 2005/03/19 22:41:27 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 struct resource *area; 51 struct platdata_mtd_ram *pdata; 52 }; 53 54 /* to_platram_info() 55 * 56 * device private data to struct platram_info conversion 57 */ 58 59 static inline struct platram_info *to_platram_info(struct device *dev) 60 { 61 return (struct platram_info *)dev_get_drvdata(dev); 62 } 63 64 /* platram_setrw 65 * 66 * call the platform device's set rw/ro control 67 * 68 * to = 0 => read-only 69 * = 1 => read-write 70 */ 71 72 static inline void platram_setrw(struct platram_info *info, int to) 73 { 74 if (info->pdata == NULL) 75 return; 76 77 if (info->pdata->set_rw != NULL) 78 (info->pdata->set_rw)(info->dev, to); 79 } 80 81 /* platram_remove 82 * 83 * called to remove the device from the driver's control 84 */ 85 86 static int platram_remove(struct device *dev) 87 { 88 struct platram_info *info = to_platram_info(dev); 89 90 dev_set_drvdata(dev, NULL); 91 92 dev_dbg(dev, "removing device\n"); 93 94 if (info == NULL) 95 return 0; 96 97 if (info->mtd) { 98 #ifdef CONFIG_MTD_PARTITIONS 99 if (info->partitions) { 100 del_mtd_partitions(info->mtd); 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 device *dev) 134 { 135 struct platform_device *pd = to_platform_device(dev); 136 struct platdata_mtd_ram *pdata; 137 struct platram_info *info; 138 struct resource *res; 139 int err = 0; 140 141 dev_dbg(dev, "probe entered\n"); 142 143 if (dev->platform_data == NULL) { 144 dev_err(dev, "no platform data supplied\n"); 145 err = -ENOENT; 146 goto exit_error; 147 } 148 149 pdata = dev->platform_data; 150 151 info = kmalloc(sizeof(*info), GFP_KERNEL); 152 if (info == NULL) { 153 dev_err(dev, "no memory for flash info\n"); 154 err = -ENOMEM; 155 goto exit_error; 156 } 157 158 memset(info, 0, sizeof(*info)); 159 dev_set_drvdata(dev, info); 160 161 info->dev = dev; 162 info->pdata = pdata; 163 164 /* get the resource for the memory mapping */ 165 166 res = platform_get_resource(pd, IORESOURCE_MEM, 0); 167 168 if (res == NULL) { 169 dev_err(dev, "no memory resource specified\n"); 170 err = -ENOENT; 171 goto exit_free; 172 } 173 174 dev_dbg(dev, "got platform resource %p (0x%lx)\n", res, res->start); 175 176 /* setup map parameters */ 177 178 info->map.phys = res->start; 179 info->map.size = (res->end - res->start) + 1; 180 info->map.name = pdata->mapname != NULL ? pdata->mapname : pd->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, pd->name); 186 if (info->area == NULL) { 187 dev_err(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(dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); 196 197 if (info->map.virt == NULL) { 198 dev_err(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(dev, "initialised map, probing for mtd\n"); 206 207 /* probe for the right mtd map driver */ 208 209 info->mtd = do_map_probe("map_ram" , &info->map); 210 if (info->mtd == NULL) { 211 dev_err(dev, "failed to probe for map_ram\n"); 212 err = -ENOMEM; 213 goto exit_free; 214 } 215 216 info->mtd->owner = THIS_MODULE; 217 218 platram_setrw(info, PLATRAM_RW); 219 220 /* check to see if there are any available partitions, or wether 221 * to add this device whole */ 222 223 #ifdef CONFIG_MTD_PARTITIONS 224 if (pdata->nr_partitions > 0) { 225 const char **probes = { NULL }; 226 227 if (pdata->probes) 228 probes = (const char **)pdata->probes; 229 230 err = parse_mtd_partitions(info->mtd, probes, 231 &info->partitions, 0); 232 if (err > 0) { 233 err = add_mtd_partitions(info->mtd, info->partitions, 234 err); 235 } 236 } 237 #endif /* CONFIG_MTD_PARTITIONS */ 238 239 if (add_mtd_device(info->mtd)) { 240 dev_err(dev, "add_mtd_device() failed\n"); 241 err = -ENOMEM; 242 } 243 244 dev_info(dev, "registered mtd device\n"); 245 return err; 246 247 exit_free: 248 platram_remove(dev); 249 exit_error: 250 return err; 251 } 252 253 /* device driver info */ 254 255 static struct device_driver platram_driver = { 256 .name = "mtd-ram", 257 .bus = &platform_bus_type, 258 .probe = platram_probe, 259 .remove = platram_remove, 260 }; 261 262 /* module init/exit */ 263 264 static int __init platram_init(void) 265 { 266 printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n"); 267 return driver_register(&platram_driver); 268 } 269 270 static void __exit platram_exit(void) 271 { 272 driver_unregister(&platram_driver); 273 } 274 275 module_init(platram_init); 276 module_exit(platram_exit); 277 278 MODULE_LICENSE("GPL"); 279 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 280 MODULE_DESCRIPTION("MTD platform RAM map driver"); 281