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 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 platform_device *dev) 60 { 61 return (struct platram_info *)platform_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 platform_device *pdev) 87 { 88 struct platram_info *info = to_platram_info(pdev); 89 90 platform_set_drvdata(pdev, NULL); 91 92 dev_dbg(&pdev->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 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 = (res->end - res->start) + 1; 179 info->map.name = pdata->mapname != NULL ? pdata->mapname : (char *)pdev->name; 180 info->map.bankwidth = pdata->bankwidth; 181 182 /* register our usage of the memory area */ 183 184 info->area = request_mem_region(res->start, info->map.size, pdev->name); 185 if (info->area == NULL) { 186 dev_err(&pdev->dev, "failed to request memory region\n"); 187 err = -EIO; 188 goto exit_free; 189 } 190 191 /* remap the memory area */ 192 193 info->map.virt = ioremap(res->start, info->map.size); 194 dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); 195 196 if (info->map.virt == NULL) { 197 dev_err(&pdev->dev, "failed to ioremap() region\n"); 198 err = -EIO; 199 goto exit_free; 200 } 201 202 simple_map_init(&info->map); 203 204 dev_dbg(&pdev->dev, "initialised map, probing for mtd\n"); 205 206 /* probe for the right mtd map driver */ 207 208 info->mtd = do_map_probe("map_ram" , &info->map); 209 if (info->mtd == NULL) { 210 dev_err(&pdev->dev, "failed to probe for map_ram\n"); 211 err = -ENOMEM; 212 goto exit_free; 213 } 214 215 info->mtd->owner = THIS_MODULE; 216 217 platram_setrw(info, PLATRAM_RW); 218 219 /* check to see if there are any available partitions, or wether 220 * to add this device whole */ 221 222 #ifdef CONFIG_MTD_PARTITIONS 223 if (pdata->nr_partitions > 0) { 224 const char **probes = { NULL }; 225 226 if (pdata->probes) 227 probes = (const char **)pdata->probes; 228 229 err = parse_mtd_partitions(info->mtd, probes, 230 &info->partitions, 0); 231 if (err > 0) { 232 err = add_mtd_partitions(info->mtd, info->partitions, 233 err); 234 } 235 } 236 #endif /* CONFIG_MTD_PARTITIONS */ 237 238 if (add_mtd_device(info->mtd)) { 239 dev_err(&pdev->dev, "add_mtd_device() failed\n"); 240 err = -ENOMEM; 241 } 242 243 dev_info(&pdev->dev, "registered mtd device\n"); 244 return err; 245 246 exit_free: 247 platram_remove(pdev); 248 exit_error: 249 return err; 250 } 251 252 /* device driver info */ 253 254 static struct platform_driver platram_driver = { 255 .probe = platram_probe, 256 .remove = platram_remove, 257 .driver = { 258 .name = "mtd-ram", 259 .owner = THIS_MODULE, 260 }, 261 }; 262 263 /* module init/exit */ 264 265 static int __init platram_init(void) 266 { 267 printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n"); 268 return platform_driver_register(&platram_driver); 269 } 270 271 static void __exit platram_exit(void) 272 { 273 platform_driver_unregister(&platram_driver); 274 } 275 276 module_init(platram_init); 277 module_exit(platram_exit); 278 279 MODULE_LICENSE("GPL"); 280 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 281 MODULE_DESCRIPTION("MTD platform RAM map driver"); 282