1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Flash memory access on SA11x0 based devices 4 * 5 * (C) 2000 Nicolas Pitre <nico@fluxnic.net> 6 */ 7 #include <linux/module.h> 8 #include <linux/types.h> 9 #include <linux/ioport.h> 10 #include <linux/kernel.h> 11 #include <linux/init.h> 12 #include <linux/errno.h> 13 #include <linux/slab.h> 14 #include <linux/platform_device.h> 15 #include <linux/err.h> 16 #include <linux/io.h> 17 18 #include <linux/mtd/mtd.h> 19 #include <linux/mtd/map.h> 20 #include <linux/mtd/partitions.h> 21 #include <linux/mtd/concat.h> 22 23 #include <mach/hardware.h> 24 #include <linux/sizes.h> 25 #include <asm/mach/flash.h> 26 27 struct sa_subdev_info { 28 char name[16]; 29 struct map_info map; 30 struct mtd_info *mtd; 31 struct flash_platform_data *plat; 32 }; 33 34 struct sa_info { 35 struct mtd_info *mtd; 36 int num_subdev; 37 struct sa_subdev_info subdev[]; 38 }; 39 40 static DEFINE_SPINLOCK(sa1100_vpp_lock); 41 static int sa1100_vpp_refcnt; 42 static void sa1100_set_vpp(struct map_info *map, int on) 43 { 44 struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map); 45 unsigned long flags; 46 47 spin_lock_irqsave(&sa1100_vpp_lock, flags); 48 if (on) { 49 if (++sa1100_vpp_refcnt == 1) /* first nested 'on' */ 50 subdev->plat->set_vpp(1); 51 } else { 52 if (--sa1100_vpp_refcnt == 0) /* last nested 'off' */ 53 subdev->plat->set_vpp(0); 54 } 55 spin_unlock_irqrestore(&sa1100_vpp_lock, flags); 56 } 57 58 static void sa1100_destroy_subdev(struct sa_subdev_info *subdev) 59 { 60 if (subdev->mtd) 61 map_destroy(subdev->mtd); 62 if (subdev->map.virt) 63 iounmap(subdev->map.virt); 64 release_mem_region(subdev->map.phys, subdev->map.size); 65 } 66 67 static int sa1100_probe_subdev(struct sa_subdev_info *subdev, struct resource *res) 68 { 69 unsigned long phys; 70 unsigned int size; 71 int ret; 72 73 phys = res->start; 74 size = res->end - phys + 1; 75 76 /* 77 * Retrieve the bankwidth from the MSC registers. 78 * We currently only implement CS0 and CS1 here. 79 */ 80 switch (phys) { 81 default: 82 printk(KERN_WARNING "SA1100 flash: unknown base address " 83 "0x%08lx, assuming CS0\n", phys); 84 fallthrough; 85 case SA1100_CS0_PHYS: 86 subdev->map.bankwidth = (MSC0 & MSC_RBW) ? 2 : 4; 87 break; 88 89 case SA1100_CS1_PHYS: 90 subdev->map.bankwidth = ((MSC0 >> 16) & MSC_RBW) ? 2 : 4; 91 break; 92 } 93 94 if (!request_mem_region(phys, size, subdev->name)) { 95 ret = -EBUSY; 96 goto out; 97 } 98 99 if (subdev->plat->set_vpp) 100 subdev->map.set_vpp = sa1100_set_vpp; 101 102 subdev->map.phys = phys; 103 subdev->map.size = size; 104 subdev->map.virt = ioremap(phys, size); 105 if (!subdev->map.virt) { 106 ret = -ENOMEM; 107 goto err; 108 } 109 110 simple_map_init(&subdev->map); 111 112 /* 113 * Now let's probe for the actual flash. Do it here since 114 * specific machine settings might have been set above. 115 */ 116 subdev->mtd = do_map_probe(subdev->plat->map_name, &subdev->map); 117 if (subdev->mtd == NULL) { 118 ret = -ENXIO; 119 goto err; 120 } 121 122 printk(KERN_INFO "SA1100 flash: CFI device at 0x%08lx, %uMiB, %d-bit\n", 123 phys, (unsigned)(subdev->mtd->size >> 20), 124 subdev->map.bankwidth * 8); 125 126 return 0; 127 128 err: 129 sa1100_destroy_subdev(subdev); 130 out: 131 return ret; 132 } 133 134 static void sa1100_destroy(struct sa_info *info, struct flash_platform_data *plat) 135 { 136 int i; 137 138 if (info->mtd) { 139 mtd_device_unregister(info->mtd); 140 if (info->mtd != info->subdev[0].mtd) 141 mtd_concat_destroy(info->mtd); 142 } 143 144 for (i = info->num_subdev - 1; i >= 0; i--) 145 sa1100_destroy_subdev(&info->subdev[i]); 146 kfree(info); 147 148 if (plat->exit) 149 plat->exit(); 150 } 151 152 static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev, 153 struct flash_platform_data *plat) 154 { 155 struct sa_info *info; 156 int nr, size, i, ret = 0; 157 158 /* 159 * Count number of devices. 160 */ 161 for (nr = 0; ; nr++) 162 if (!platform_get_resource(pdev, IORESOURCE_MEM, nr)) 163 break; 164 165 if (nr == 0) { 166 ret = -ENODEV; 167 goto out; 168 } 169 170 size = sizeof(struct sa_info) + sizeof(struct sa_subdev_info) * nr; 171 172 /* 173 * Allocate the map_info structs in one go. 174 */ 175 info = kzalloc(size, GFP_KERNEL); 176 if (!info) { 177 ret = -ENOMEM; 178 goto out; 179 } 180 181 if (plat->init) { 182 ret = plat->init(); 183 if (ret) 184 goto err; 185 } 186 187 /* 188 * Claim and then map the memory regions. 189 */ 190 for (i = 0; i < nr; i++) { 191 struct sa_subdev_info *subdev = &info->subdev[i]; 192 struct resource *res; 193 194 res = platform_get_resource(pdev, IORESOURCE_MEM, i); 195 if (!res) 196 break; 197 198 subdev->map.name = subdev->name; 199 sprintf(subdev->name, "%s-%d", plat->name, i); 200 subdev->plat = plat; 201 202 ret = sa1100_probe_subdev(subdev, res); 203 if (ret) 204 break; 205 } 206 207 info->num_subdev = i; 208 209 /* 210 * ENXIO is special. It means we didn't find a chip when we probed. 211 */ 212 if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0)) 213 goto err; 214 215 /* 216 * If we found one device, don't bother with concat support. If 217 * we found multiple devices, use concat if we have it available, 218 * otherwise fail. Either way, it'll be called "sa1100". 219 */ 220 if (info->num_subdev == 1) { 221 strcpy(info->subdev[0].name, plat->name); 222 info->mtd = info->subdev[0].mtd; 223 ret = 0; 224 } else if (info->num_subdev > 1) { 225 struct mtd_info **cdev; 226 227 cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL); 228 if (!cdev) { 229 ret = -ENOMEM; 230 goto err; 231 } 232 233 /* 234 * We detected multiple devices. Concatenate them together. 235 */ 236 for (i = 0; i < info->num_subdev; i++) 237 cdev[i] = info->subdev[i].mtd; 238 239 info->mtd = mtd_concat_create(cdev, info->num_subdev, 240 plat->name); 241 kfree(cdev); 242 if (info->mtd == NULL) { 243 ret = -ENXIO; 244 goto err; 245 } 246 } 247 info->mtd->dev.parent = &pdev->dev; 248 249 if (ret == 0) 250 return info; 251 252 err: 253 sa1100_destroy(info, plat); 254 out: 255 return ERR_PTR(ret); 256 } 257 258 static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL }; 259 260 static int sa1100_mtd_probe(struct platform_device *pdev) 261 { 262 struct flash_platform_data *plat = dev_get_platdata(&pdev->dev); 263 struct sa_info *info; 264 int err; 265 266 if (!plat) 267 return -ENODEV; 268 269 info = sa1100_setup_mtd(pdev, plat); 270 if (IS_ERR(info)) { 271 err = PTR_ERR(info); 272 goto out; 273 } 274 275 /* 276 * Partition selection stuff. 277 */ 278 mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts, 279 plat->nr_parts); 280 281 platform_set_drvdata(pdev, info); 282 err = 0; 283 284 out: 285 return err; 286 } 287 288 static int sa1100_mtd_remove(struct platform_device *pdev) 289 { 290 struct sa_info *info = platform_get_drvdata(pdev); 291 struct flash_platform_data *plat = dev_get_platdata(&pdev->dev); 292 293 sa1100_destroy(info, plat); 294 295 return 0; 296 } 297 298 static struct platform_driver sa1100_mtd_driver = { 299 .probe = sa1100_mtd_probe, 300 .remove = sa1100_mtd_remove, 301 .driver = { 302 .name = "sa1100-mtd", 303 }, 304 }; 305 306 module_platform_driver(sa1100_mtd_driver); 307 308 MODULE_AUTHOR("Nicolas Pitre"); 309 MODULE_DESCRIPTION("SA1100 CFI map driver"); 310 MODULE_LICENSE("GPL"); 311 MODULE_ALIAS("platform:sa1100-mtd"); 312