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 resource *area; 48 struct platdata_mtd_ram *pdata; 49 }; 50 51 /* to_platram_info() 52 * 53 * device private data to struct platram_info conversion 54 */ 55 56 static inline struct platram_info *to_platram_info(struct platform_device *dev) 57 { 58 return platform_get_drvdata(dev); 59 } 60 61 /* platram_setrw 62 * 63 * call the platform device's set rw/ro control 64 * 65 * to = 0 => read-only 66 * = 1 => read-write 67 */ 68 69 static inline void platram_setrw(struct platram_info *info, int to) 70 { 71 if (info->pdata == NULL) 72 return; 73 74 if (info->pdata->set_rw != NULL) 75 (info->pdata->set_rw)(info->dev, to); 76 } 77 78 /* platram_remove 79 * 80 * called to remove the device from the driver's control 81 */ 82 83 static int platram_remove(struct platform_device *pdev) 84 { 85 struct platram_info *info = to_platram_info(pdev); 86 87 dev_dbg(&pdev->dev, "removing device\n"); 88 89 if (info == NULL) 90 return 0; 91 92 if (info->mtd) { 93 mtd_device_unregister(info->mtd); 94 map_destroy(info->mtd); 95 } 96 97 /* ensure ram is left read-only */ 98 99 platram_setrw(info, PLATRAM_RO); 100 101 /* release resources */ 102 103 if (info->area) { 104 release_resource(info->area); 105 kfree(info->area); 106 } 107 108 if (info->map.virt != NULL) 109 iounmap(info->map.virt); 110 111 kfree(info); 112 113 return 0; 114 } 115 116 /* platram_probe 117 * 118 * called from device drive system when a device matching our 119 * driver is found. 120 */ 121 122 static int platram_probe(struct platform_device *pdev) 123 { 124 struct platdata_mtd_ram *pdata; 125 struct platram_info *info; 126 struct resource *res; 127 int err = 0; 128 129 dev_dbg(&pdev->dev, "probe entered\n"); 130 131 if (dev_get_platdata(&pdev->dev) == NULL) { 132 dev_err(&pdev->dev, "no platform data supplied\n"); 133 err = -ENOENT; 134 goto exit_error; 135 } 136 137 pdata = dev_get_platdata(&pdev->dev); 138 139 info = kzalloc(sizeof(*info), GFP_KERNEL); 140 if (info == NULL) { 141 dev_err(&pdev->dev, "no memory for flash info\n"); 142 err = -ENOMEM; 143 goto exit_error; 144 } 145 146 platform_set_drvdata(pdev, info); 147 148 info->dev = &pdev->dev; 149 info->pdata = pdata; 150 151 /* get the resource for the memory mapping */ 152 153 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 154 155 if (res == NULL) { 156 dev_err(&pdev->dev, "no memory resource specified\n"); 157 err = -ENOENT; 158 goto exit_free; 159 } 160 161 dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res, 162 (unsigned long long)res->start); 163 164 /* setup map parameters */ 165 166 info->map.phys = res->start; 167 info->map.size = resource_size(res); 168 info->map.name = pdata->mapname != NULL ? 169 (char *)pdata->mapname : (char *)pdev->name; 170 info->map.bankwidth = pdata->bankwidth; 171 172 /* register our usage of the memory area */ 173 174 info->area = request_mem_region(res->start, info->map.size, pdev->name); 175 if (info->area == NULL) { 176 dev_err(&pdev->dev, "failed to request memory region\n"); 177 err = -EIO; 178 goto exit_free; 179 } 180 181 /* remap the memory area */ 182 183 info->map.virt = ioremap(res->start, info->map.size); 184 dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); 185 186 if (info->map.virt == NULL) { 187 dev_err(&pdev->dev, "failed to ioremap() region\n"); 188 err = -EIO; 189 goto exit_free; 190 } 191 192 simple_map_init(&info->map); 193 194 dev_dbg(&pdev->dev, "initialised map, probing for mtd\n"); 195 196 /* probe for the right mtd map driver 197 * supplied by the platform_data struct */ 198 199 if (pdata->map_probes) { 200 const char * const *map_probes = pdata->map_probes; 201 202 for ( ; !info->mtd && *map_probes; map_probes++) 203 info->mtd = do_map_probe(*map_probes , &info->map); 204 } 205 /* fallback to map_ram */ 206 else 207 info->mtd = do_map_probe("map_ram", &info->map); 208 209 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 info->mtd->dev.parent = &pdev->dev; 217 218 platram_setrw(info, PLATRAM_RW); 219 220 /* check to see if there are any available partitions, or whether 221 * to add this device whole */ 222 223 err = mtd_device_parse_register(info->mtd, pdata->probes, NULL, 224 pdata->partitions, 225 pdata->nr_partitions); 226 if (!err) 227 dev_info(&pdev->dev, "registered mtd device\n"); 228 229 if (pdata->nr_partitions) { 230 /* add the whole device. */ 231 err = mtd_device_register(info->mtd, NULL, 0); 232 if (err) { 233 dev_err(&pdev->dev, 234 "failed to register the entire device\n"); 235 } 236 } 237 238 return err; 239 240 exit_free: 241 platram_remove(pdev); 242 exit_error: 243 return err; 244 } 245 246 /* device driver info */ 247 248 /* work with hotplug and coldplug */ 249 MODULE_ALIAS("platform:mtd-ram"); 250 251 static struct platform_driver platram_driver = { 252 .probe = platram_probe, 253 .remove = platram_remove, 254 .driver = { 255 .name = "mtd-ram", 256 .owner = THIS_MODULE, 257 }, 258 }; 259 260 module_platform_driver(platram_driver); 261 262 MODULE_LICENSE("GPL"); 263 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 264 MODULE_DESCRIPTION("MTD platform RAM map driver"); 265