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 platform 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 mtd_device_unregister(info->mtd); 98 if (info->partitions) { 99 if (info->free_partitions) 100 kfree(info->partitions); 101 } 102 map_destroy(info->mtd); 103 } 104 105 /* ensure ram is left read-only */ 106 107 platram_setrw(info, PLATRAM_RO); 108 109 /* release resources */ 110 111 if (info->area) { 112 release_resource(info->area); 113 kfree(info->area); 114 } 115 116 if (info->map.virt != NULL) 117 iounmap(info->map.virt); 118 119 kfree(info); 120 121 return 0; 122 } 123 124 /* platram_probe 125 * 126 * called from device drive system when a device matching our 127 * driver is found. 128 */ 129 130 static int platram_probe(struct platform_device *pdev) 131 { 132 struct platdata_mtd_ram *pdata; 133 struct platram_info *info; 134 struct resource *res; 135 int err = 0; 136 137 dev_dbg(&pdev->dev, "probe entered\n"); 138 139 if (pdev->dev.platform_data == NULL) { 140 dev_err(&pdev->dev, "no platform data supplied\n"); 141 err = -ENOENT; 142 goto exit_error; 143 } 144 145 pdata = pdev->dev.platform_data; 146 147 info = kzalloc(sizeof(*info), GFP_KERNEL); 148 if (info == NULL) { 149 dev_err(&pdev->dev, "no memory for flash info\n"); 150 err = -ENOMEM; 151 goto exit_error; 152 } 153 154 platform_set_drvdata(pdev, info); 155 156 info->dev = &pdev->dev; 157 info->pdata = pdata; 158 159 /* get the resource for the memory mapping */ 160 161 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 162 163 if (res == NULL) { 164 dev_err(&pdev->dev, "no memory resource specified\n"); 165 err = -ENOENT; 166 goto exit_free; 167 } 168 169 dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res, 170 (unsigned long long)res->start); 171 172 /* setup map parameters */ 173 174 info->map.phys = res->start; 175 info->map.size = resource_size(res); 176 info->map.name = pdata->mapname != NULL ? 177 (char *)pdata->mapname : (char *)pdev->name; 178 info->map.bankwidth = pdata->bankwidth; 179 180 /* register our usage of the memory area */ 181 182 info->area = request_mem_region(res->start, info->map.size, pdev->name); 183 if (info->area == NULL) { 184 dev_err(&pdev->dev, "failed to request memory region\n"); 185 err = -EIO; 186 goto exit_free; 187 } 188 189 /* remap the memory area */ 190 191 info->map.virt = ioremap(res->start, info->map.size); 192 dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); 193 194 if (info->map.virt == NULL) { 195 dev_err(&pdev->dev, "failed to ioremap() region\n"); 196 err = -EIO; 197 goto exit_free; 198 } 199 200 simple_map_init(&info->map); 201 202 dev_dbg(&pdev->dev, "initialised map, probing for mtd\n"); 203 204 /* probe for the right mtd map driver 205 * supplied by the platform_data struct */ 206 207 if (pdata->map_probes) { 208 const char **map_probes = pdata->map_probes; 209 210 for ( ; !info->mtd && *map_probes; map_probes++) 211 info->mtd = do_map_probe(*map_probes , &info->map); 212 } 213 /* fallback to map_ram */ 214 else 215 info->mtd = do_map_probe("map_ram", &info->map); 216 217 if (info->mtd == NULL) { 218 dev_err(&pdev->dev, "failed to probe for map_ram\n"); 219 err = -ENOMEM; 220 goto exit_free; 221 } 222 223 info->mtd->owner = THIS_MODULE; 224 info->mtd->dev.parent = &pdev->dev; 225 226 platram_setrw(info, PLATRAM_RW); 227 228 /* check to see if there are any available partitions, or wether 229 * to add this device whole */ 230 231 if (!pdata->nr_partitions) { 232 /* try to probe using the supplied probe type */ 233 if (pdata->probes) { 234 err = parse_mtd_partitions(info->mtd, pdata->probes, 235 &info->partitions, 0); 236 info->free_partitions = 1; 237 if (err > 0) 238 err = mtd_device_register(info->mtd, 239 info->partitions, err); 240 } 241 } 242 /* use the static mapping */ 243 else 244 err = mtd_device_register(info->mtd, pdata->partitions, 245 pdata->nr_partitions); 246 if (!err) 247 dev_info(&pdev->dev, "registered mtd device\n"); 248 249 /* add the whole device. */ 250 err = mtd_device_register(info->mtd, NULL, 0); 251 if (err) 252 dev_err(&pdev->dev, "failed to register the entire device\n"); 253 254 return err; 255 256 exit_free: 257 platram_remove(pdev); 258 exit_error: 259 return err; 260 } 261 262 /* device driver info */ 263 264 /* work with hotplug and coldplug */ 265 MODULE_ALIAS("platform:mtd-ram"); 266 267 static struct platform_driver platram_driver = { 268 .probe = platram_probe, 269 .remove = platram_remove, 270 .driver = { 271 .name = "mtd-ram", 272 .owner = THIS_MODULE, 273 }, 274 }; 275 276 /* module init/exit */ 277 278 static int __init platram_init(void) 279 { 280 printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n"); 281 return platform_driver_register(&platram_driver); 282 } 283 284 static void __exit platram_exit(void) 285 { 286 platform_driver_unregister(&platram_driver); 287 } 288 289 module_init(platram_init); 290 module_exit(platram_exit); 291 292 MODULE_LICENSE("GPL"); 293 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 294 MODULE_DESCRIPTION("MTD platform RAM map driver"); 295