mtd/maps/sa1100-flash.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Flash memory access on SA11x0 based devices
0004  *
0005  * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
0006  */
0007 #include <linux/module.h>
0008 #include <linux/types.h>
0009 #include <linux/ioport.h>
0010 #include <linux/kernel.h>
0011 #include <linux/init.h>
0012 #include <linux/errno.h>
0013 #include <linux/slab.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/err.h>
0016 #include <linux/io.h>
0017
0018 #include <linux/mtd/mtd.h>
0019 #include <linux/mtd/map.h>
0020 #include <linux/mtd/partitions.h>
0021 #include <linux/mtd/concat.h>
0022
0023 #include <mach/hardware.h>
0024 #include <linux/sizes.h>
0025 #include <asm/mach/flash.h>
0026
0027 struct sa_subdev_info {
0028     char name[16];
0029     struct map_info map;
0030     struct mtd_info *mtd;
0031     struct flash_platform_data *plat;
0032 };
0033
0034 struct sa_info {
0035     struct mtd_info     *mtd;
0036     int         num_subdev;
0037     struct sa_subdev_info   subdev[];
0038 };
0039
0040 static DEFINE_SPINLOCK(sa1100_vpp_lock);
0041 static int sa1100_vpp_refcnt;
0042 static void sa1100_set_vpp(struct map_info *map, int on)
0043 {
0044     struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map);
0045     unsigned long flags;
0046
0047     spin_lock_irqsave(&sa1100_vpp_lock, flags);
0048     if (on) {
0049         if (++sa1100_vpp_refcnt == 1)   /* first nested 'on' */
0050             subdev->plat->set_vpp(1);
0051     } else {
0052         if (--sa1100_vpp_refcnt == 0)   /* last nested 'off' */
0053             subdev->plat->set_vpp(0);
0054     }
0055     spin_unlock_irqrestore(&sa1100_vpp_lock, flags);
0056 }
0057
0058 static void sa1100_destroy_subdev(struct sa_subdev_info *subdev)
0059 {
0060     if (subdev->mtd)
0061         map_destroy(subdev->mtd);
0062     if (subdev->map.virt)
0063         iounmap(subdev->map.virt);
0064     release_mem_region(subdev->map.phys, subdev->map.size);
0065 }
0066
0067 static int sa1100_probe_subdev(struct sa_subdev_info *subdev, struct resource *res)
0068 {
0069     unsigned long phys;
0070     unsigned int size;
0071     int ret;
0072
0073     phys = res->start;
0074     size = res->end - phys + 1;
0075
0076     /*
0077      * Retrieve the bankwidth from the MSC registers.
0078      * We currently only implement CS0 and CS1 here.
0079      */
0080     switch (phys) {
0081     default:
0082         printk(KERN_WARNING "SA1100 flash: unknown base address "
0083                "0x%08lx, assuming CS0\n", phys);
0084         fallthrough;
0085     case SA1100_CS0_PHYS:
0086         subdev->map.bankwidth = (MSC0 & MSC_RBW) ? 2 : 4;
0087         break;
0088
0089     case SA1100_CS1_PHYS:
0090         subdev->map.bankwidth = ((MSC0 >> 16) & MSC_RBW) ? 2 : 4;
0091         break;
0092     }
0093
0094     if (!request_mem_region(phys, size, subdev->name)) {
0095         ret = -EBUSY;
0096         goto out;
0097     }
0098
0099     if (subdev->plat->set_vpp)
0100         subdev->map.set_vpp = sa1100_set_vpp;
0101
0102     subdev->map.phys = phys;
0103     subdev->map.size = size;
0104     subdev->map.virt = ioremap(phys, size);
0105     if (!subdev->map.virt) {
0106         ret = -ENOMEM;
0107         goto err;
0108     }
0109
0110     simple_map_init(&subdev->map);
0111
0112     /*
0113      * Now let's probe for the actual flash.  Do it here since
0114      * specific machine settings might have been set above.
0115      */
0116     subdev->mtd = do_map_probe(subdev->plat->map_name, &subdev->map);
0117     if (subdev->mtd == NULL) {
0118         ret = -ENXIO;
0119         goto err;
0120     }
0121
0122     printk(KERN_INFO "SA1100 flash: CFI device at 0x%08lx, %uMiB, %d-bit\n",
0123         phys, (unsigned)(subdev->mtd->size >> 20),
0124         subdev->map.bankwidth * 8);
0125
0126     return 0;
0127
0128  err:
0129     sa1100_destroy_subdev(subdev);
0130  out:
0131     return ret;
0132 }
0133
0134 static void sa1100_destroy(struct sa_info *info, struct flash_platform_data *plat)
0135 {
0136     int i;
0137
0138     if (info->mtd) {
0139         mtd_device_unregister(info->mtd);
0140         if (info->mtd != info->subdev[0].mtd)
0141             mtd_concat_destroy(info->mtd);
0142     }
0143
0144     for (i = info->num_subdev - 1; i >= 0; i--)
0145         sa1100_destroy_subdev(&info->subdev[i]);
0146     kfree(info);
0147
0148     if (plat->exit)
0149         plat->exit();
0150 }
0151
0152 static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev,
0153                     struct flash_platform_data *plat)
0154 {
0155     struct sa_info *info;
0156     int nr, size, i, ret = 0;
0157
0158     /*
0159      * Count number of devices.
0160      */
0161     for (nr = 0; ; nr++)
0162         if (!platform_get_resource(pdev, IORESOURCE_MEM, nr))
0163             break;
0164
0165     if (nr == 0) {
0166         ret = -ENODEV;
0167         goto out;
0168     }
0169
0170     size = sizeof(struct sa_info) + sizeof(struct sa_subdev_info) * nr;
0171
0172     /*
0173      * Allocate the map_info structs in one go.
0174      */
0175     info = kzalloc(size, GFP_KERNEL);
0176     if (!info) {
0177         ret = -ENOMEM;
0178         goto out;
0179     }
0180
0181     if (plat->init) {
0182         ret = plat->init();
0183         if (ret)
0184             goto err;
0185     }
0186
0187     /*
0188      * Claim and then map the memory regions.
0189      */
0190     for (i = 0; i < nr; i++) {
0191         struct sa_subdev_info *subdev = &info->subdev[i];
0192         struct resource *res;
0193
0194         res = platform_get_resource(pdev, IORESOURCE_MEM, i);
0195         if (!res)
0196             break;
0197
0198         subdev->map.name = subdev->name;
0199         sprintf(subdev->name, "%s-%d", plat->name, i);
0200         subdev->plat = plat;
0201
0202         ret = sa1100_probe_subdev(subdev, res);
0203         if (ret)
0204             break;
0205     }
0206
0207     info->num_subdev = i;
0208
0209     /*
0210      * ENXIO is special.  It means we didn't find a chip when we probed.
0211      */
0212     if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0))
0213         goto err;
0214
0215     /*
0216      * If we found one device, don't bother with concat support.  If
0217      * we found multiple devices, use concat if we have it available,
0218      * otherwise fail.  Either way, it'll be called "sa1100".
0219      */
0220     if (info->num_subdev == 1) {
0221         strcpy(info->subdev[0].name, plat->name);
0222         info->mtd = info->subdev[0].mtd;
0223         ret = 0;
0224     } else if (info->num_subdev > 1) {
0225         struct mtd_info **cdev;
0226
0227         cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL);
0228         if (!cdev) {
0229             ret = -ENOMEM;
0230             goto err;
0231         }
0232
0233         /*
0234          * We detected multiple devices.  Concatenate them together.
0235          */
0236         for (i = 0; i < info->num_subdev; i++)
0237             cdev[i] = info->subdev[i].mtd;
0238
0239         info->mtd = mtd_concat_create(cdev, info->num_subdev,
0240                           plat->name);
0241         kfree(cdev);
0242         if (info->mtd == NULL) {
0243             ret = -ENXIO;
0244             goto err;
0245         }
0246     }
0247     info->mtd->dev.parent = &pdev->dev;
0248
0249     if (ret == 0)
0250         return info;
0251
0252  err:
0253     sa1100_destroy(info, plat);
0254  out:
0255     return ERR_PTR(ret);
0256 }
0257
0258 static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL };
0259
0260 static int sa1100_mtd_probe(struct platform_device *pdev)
0261 {
0262     struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
0263     struct sa_info *info;
0264     int err;
0265
0266     if (!plat)
0267         return -ENODEV;
0268
0269     info = sa1100_setup_mtd(pdev, plat);
0270     if (IS_ERR(info)) {
0271         err = PTR_ERR(info);
0272         goto out;
0273     }
0274
0275     /*
0276      * Partition selection stuff.
0277      */
0278     mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
0279                   plat->nr_parts);
0280
0281     platform_set_drvdata(pdev, info);
0282     err = 0;
0283
0284  out:
0285     return err;
0286 }
0287
0288 static int sa1100_mtd_remove(struct platform_device *pdev)
0289 {
0290     struct sa_info *info = platform_get_drvdata(pdev);
0291     struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
0292
0293     sa1100_destroy(info, plat);
0294
0295     return 0;
0296 }
0297
0298 static struct platform_driver sa1100_mtd_driver = {
0299     .probe      = sa1100_mtd_probe,
0300     .remove     = sa1100_mtd_remove,
0301     .driver     = {
0302         .name   = "sa1100-mtd",
0303     },
0304 };
0305
0306 module_platform_driver(sa1100_mtd_driver);
0307
0308 MODULE_AUTHOR("Nicolas Pitre");
0309 MODULE_DESCRIPTION("SA1100 CFI map driver");
0310 MODULE_LICENSE("GPL");
0311 MODULE_ALIAS("platform:sa1100-mtd");