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/kernel.h> 27 #include <linux/string.h> 28 #include <linux/ioport.h> 29 #include <linux/device.h> 30 #include <linux/slab.h> 31 #include <linux/platform_device.h> 32 33 #include <linux/mtd/mtd.h> 34 #include <linux/mtd/map.h> 35 #include <linux/mtd/partitions.h> 36 #include <linux/mtd/plat-ram.h> 37 38 #include <asm/io.h> 39 40 /* private structure for each mtd platform ram device created */ 41 42 struct platram_info { 43 struct device *dev; 44 struct mtd_info *mtd; 45 struct map_info map; 46 struct platdata_mtd_ram *pdata; 47 }; 48 49 /* to_platram_info() 50 * 51 * device private data to struct platram_info conversion 52 */ 53 54 static inline struct platram_info *to_platram_info(struct platform_device *dev) 55 { 56 return platform_get_drvdata(dev); 57 } 58 59 /* platram_setrw 60 * 61 * call the platform device's set rw/ro control 62 * 63 * to = 0 => read-only 64 * = 1 => read-write 65 */ 66 67 static inline void platram_setrw(struct platram_info *info, int to) 68 { 69 if (info->pdata == NULL) 70 return; 71 72 if (info->pdata->set_rw != NULL) 73 (info->pdata->set_rw)(info->dev, to); 74 } 75 76 /* platram_remove 77 * 78 * called to remove the device from the driver's control 79 */ 80 81 static int platram_remove(struct platform_device *pdev) 82 { 83 struct platram_info *info = to_platram_info(pdev); 84 85 dev_dbg(&pdev->dev, "removing device\n"); 86 87 if (info == NULL) 88 return 0; 89 90 if (info->mtd) { 91 mtd_device_unregister(info->mtd); 92 map_destroy(info->mtd); 93 } 94 95 /* ensure ram is left read-only */ 96 97 platram_setrw(info, PLATRAM_RO); 98 99 kfree(info); 100 101 return 0; 102 } 103 104 /* platram_probe 105 * 106 * called from device drive system when a device matching our 107 * driver is found. 108 */ 109 110 static int platram_probe(struct platform_device *pdev) 111 { 112 struct platdata_mtd_ram *pdata; 113 struct platram_info *info; 114 struct resource *res; 115 int err = 0; 116 117 dev_dbg(&pdev->dev, "probe entered\n"); 118 119 if (dev_get_platdata(&pdev->dev) == NULL) { 120 dev_err(&pdev->dev, "no platform data supplied\n"); 121 err = -ENOENT; 122 goto exit_error; 123 } 124 125 pdata = dev_get_platdata(&pdev->dev); 126 127 info = kzalloc(sizeof(*info), GFP_KERNEL); 128 if (info == NULL) { 129 err = -ENOMEM; 130 goto exit_error; 131 } 132 133 platform_set_drvdata(pdev, info); 134 135 info->dev = &pdev->dev; 136 info->pdata = pdata; 137 138 /* get the resource for the memory mapping */ 139 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 140 info->map.virt = devm_ioremap_resource(&pdev->dev, res); 141 if (IS_ERR(info->map.virt)) { 142 err = PTR_ERR(info->map.virt); 143 dev_err(&pdev->dev, "failed to ioremap() region\n"); 144 goto exit_free; 145 } 146 147 dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res, 148 (unsigned long long)res->start); 149 150 /* setup map parameters */ 151 152 info->map.phys = res->start; 153 info->map.size = resource_size(res); 154 info->map.name = pdata->mapname != NULL ? 155 (char *)pdata->mapname : (char *)pdev->name; 156 info->map.bankwidth = pdata->bankwidth; 157 158 dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); 159 160 simple_map_init(&info->map); 161 162 dev_dbg(&pdev->dev, "initialised map, probing for mtd\n"); 163 164 /* probe for the right mtd map driver 165 * supplied by the platform_data struct */ 166 167 if (pdata->map_probes) { 168 const char * const *map_probes = pdata->map_probes; 169 170 for ( ; !info->mtd && *map_probes; map_probes++) 171 info->mtd = do_map_probe(*map_probes , &info->map); 172 } 173 /* fallback to map_ram */ 174 else 175 info->mtd = do_map_probe("map_ram", &info->map); 176 177 if (info->mtd == NULL) { 178 dev_err(&pdev->dev, "failed to probe for map_ram\n"); 179 err = -ENOMEM; 180 goto exit_free; 181 } 182 183 info->mtd->dev.parent = &pdev->dev; 184 185 platram_setrw(info, PLATRAM_RW); 186 187 /* check to see if there are any available partitions, or whether 188 * to add this device whole */ 189 190 err = mtd_device_parse_register(info->mtd, pdata->probes, NULL, 191 pdata->partitions, 192 pdata->nr_partitions); 193 if (!err) 194 dev_info(&pdev->dev, "registered mtd device\n"); 195 196 if (pdata->nr_partitions) { 197 /* add the whole device. */ 198 err = mtd_device_register(info->mtd, NULL, 0); 199 if (err) { 200 dev_err(&pdev->dev, 201 "failed to register the entire device\n"); 202 } 203 } 204 205 return err; 206 207 exit_free: 208 platram_remove(pdev); 209 exit_error: 210 return err; 211 } 212 213 /* device driver info */ 214 215 /* work with hotplug and coldplug */ 216 MODULE_ALIAS("platform:mtd-ram"); 217 218 static struct platform_driver platram_driver = { 219 .probe = platram_probe, 220 .remove = platram_remove, 221 .driver = { 222 .name = "mtd-ram", 223 }, 224 }; 225 226 module_platform_driver(platram_driver); 227 228 MODULE_LICENSE("GPL"); 229 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); 230 MODULE_DESCRIPTION("MTD platform RAM map driver"); 231