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, 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 /* 171 * Allocate the map_info structs in one go. 172 */ 173 info = kzalloc(struct_size(info, subdev, nr), GFP_KERNEL); 174 if (!info) { 175 ret = -ENOMEM; 176 goto out; 177 } 178 179 if (plat->init) { 180 ret = plat->init(); 181 if (ret) 182 goto err; 183 } 184 185 /* 186 * Claim and then map the memory regions. 187 */ 188 for (i = 0; i < nr; i++) { 189 struct sa_subdev_info *subdev = &info->subdev[i]; 190 struct resource *res; 191 192 res = platform_get_resource(pdev, IORESOURCE_MEM, i); 193 if (!res) 194 break; 195 196 subdev->map.name = subdev->name; 197 sprintf(subdev->name, "%s-%d", plat->name, i); 198 subdev->plat = plat; 199 200 ret = sa1100_probe_subdev(subdev, res); 201 if (ret) 202 break; 203 } 204 205 info->num_subdev = i; 206 207 /* 208 * ENXIO is special. It means we didn't find a chip when we probed. 209 */ 210 if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0)) 211 goto err; 212 213 /* 214 * If we found one device, don't bother with concat support. If 215 * we found multiple devices, use concat if we have it available, 216 * otherwise fail. Either way, it'll be called "sa1100". 217 */ 218 if (info->num_subdev == 1) { 219 strcpy(info->subdev[0].name, plat->name); 220 info->mtd = info->subdev[0].mtd; 221 ret = 0; 222 } else if (info->num_subdev > 1) { 223 struct mtd_info **cdev; 224 225 cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL); 226 if (!cdev) { 227 ret = -ENOMEM; 228 goto err; 229 } 230 231 /* 232 * We detected multiple devices. Concatenate them together. 233 */ 234 for (i = 0; i < info->num_subdev; i++) 235 cdev[i] = info->subdev[i].mtd; 236 237 info->mtd = mtd_concat_create(cdev, info->num_subdev, 238 plat->name); 239 kfree(cdev); 240 if (info->mtd == NULL) { 241 ret = -ENXIO; 242 goto err; 243 } 244 } 245 info->mtd->dev.parent = &pdev->dev; 246 247 if (ret == 0) 248 return info; 249 250 err: 251 sa1100_destroy(info, plat); 252 out: 253 return ERR_PTR(ret); 254 } 255 256 static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL }; 257 258 static int sa1100_mtd_probe(struct platform_device *pdev) 259 { 260 struct flash_platform_data *plat = dev_get_platdata(&pdev->dev); 261 struct sa_info *info; 262 int err; 263 264 if (!plat) 265 return -ENODEV; 266 267 info = sa1100_setup_mtd(pdev, plat); 268 if (IS_ERR(info)) { 269 err = PTR_ERR(info); 270 goto out; 271 } 272 273 /* 274 * Partition selection stuff. 275 */ 276 mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts, 277 plat->nr_parts); 278 279 platform_set_drvdata(pdev, info); 280 err = 0; 281 282 out: 283 return err; 284 } 285 286 static void sa1100_mtd_remove(struct platform_device *pdev) 287 { 288 struct sa_info *info = platform_get_drvdata(pdev); 289 struct flash_platform_data *plat = dev_get_platdata(&pdev->dev); 290 291 sa1100_destroy(info, plat); 292 } 293 294 static struct platform_driver sa1100_mtd_driver = { 295 .probe = sa1100_mtd_probe, 296 .remove_new = sa1100_mtd_remove, 297 .driver = { 298 .name = "sa1100-mtd", 299 }, 300 }; 301 302 module_platform_driver(sa1100_mtd_driver); 303 304 MODULE_AUTHOR("Nicolas Pitre"); 305 MODULE_DESCRIPTION("SA1100 CFI map driver"); 306 MODULE_LICENSE("GPL"); 307 MODULE_ALIAS("platform:sa1100-mtd"); 308