drivers/mtd/maps/sun_uflash.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* sun_uflash.c - Driver for user-programmable flash on
   3  *                Sun Microsystems SME boardsets.
   4  *
   5  * This driver does NOT provide access to the OBP-flash for
   6  * safety reasons-- use <linux>/drivers/sbus/char/flash.c instead.
   7  *
   8  * Copyright (c) 2001 Eric Brower (ebrower@usa.net)
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/fs.h>
  14 #include <linux/errno.h>
  15 #include <linux/ioport.h>
  16 #include <linux/of.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19 #include <asm/prom.h>
  20 #include <linux/uaccess.h>
  21 #include <asm/io.h>
  22
  23 #include <linux/mtd/mtd.h>
  24 #include <linux/mtd/map.h>
  25
  26 #define UFLASH_OBPNAME  "flashprom"
  27 #define DRIVER_NAME     "sun_uflash"
  28 #define PFX             DRIVER_NAME ": "
  29
  30 #define UFLASH_WINDOW_SIZE      0x200000
  31 #define UFLASH_BUSWIDTH         1                       /* EBus is 8-bit */
  32
  33 MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
  34 MODULE_DESCRIPTION("User-programmable flash device on Sun Microsystems boardsets");
  35 MODULE_LICENSE("GPL");
  36 MODULE_VERSION("2.1");
  37
  38 struct uflash_dev {
  39         const char              *name;  /* device name */
  40         struct map_info         map;    /* mtd map info */
  41         struct mtd_info         *mtd;   /* mtd info */
  42 };
  43
  44 struct map_info uflash_map_templ = {
  45         .name =         "SUNW,???-????",
  46         .size =         UFLASH_WINDOW_SIZE,
  47         .bankwidth =    UFLASH_BUSWIDTH,
  48 };
  49
  50 static int uflash_devinit(struct platform_device *op, struct device_node *dp)
  51 {
  52         struct uflash_dev *up;
  53
  54         if (op->resource[1].flags) {
  55                 /* Non-CFI userflash device-- once I find one we
  56                  * can work on supporting it.
  57                  */
  58                 printk(KERN_ERR PFX "Unsupported device at %pOF, 0x%llx\n",
  59                        dp, (unsigned long long)op->resource[0].start);
  60
  61                 return -ENODEV;
  62         }
  63
  64         up = kzalloc(sizeof(struct uflash_dev), GFP_KERNEL);
  65         if (!up)
  66                 return -ENOMEM;
  67
  68         /* copy defaults and tweak parameters */
  69         memcpy(&up->map, &uflash_map_templ, sizeof(uflash_map_templ));
  70
  71         up->map.size = resource_size(&op->resource[0]);
  72
  73         up->name = of_get_property(dp, "model", NULL);
  74         if (up->name && 0 < strlen(up->name))
  75                 up->map.name = up->name;
  76
  77         up->map.phys = op->resource[0].start;
  78
  79         up->map.virt = of_ioremap(&op->resource[0], 0, up->map.size,
  80                                   DRIVER_NAME);
  81         if (!up->map.virt) {
  82                 printk(KERN_ERR PFX "Failed to map device.\n");
  83                 kfree(up);
  84
  85                 return -EINVAL;
  86         }
  87
  88         simple_map_init(&up->map);
  89
  90         /* MTD registration */
  91         up->mtd = do_map_probe("cfi_probe", &up->map);
  92         if (!up->mtd) {
  93                 of_iounmap(&op->resource[0], up->map.virt, up->map.size);
  94                 kfree(up);
  95
  96                 return -ENXIO;
  97         }
  98
  99         up->mtd->owner = THIS_MODULE;
 100
 101         mtd_device_register(up->mtd, NULL, 0);
 102
 103         dev_set_drvdata(&op->dev, up);
 104
 105         return 0;
 106 }
 107
 108 static int uflash_probe(struct platform_device *op)
 109 {
 110         struct device_node *dp = op->dev.of_node;
 111
 112         /* Flashprom must have the "user" property in order to
 113          * be used by this driver.
 114          */
 115         if (!of_property_read_bool(dp, "user"))
 116                 return -ENODEV;
 117
 118         return uflash_devinit(op, dp);
 119 }
 120
 121 static void uflash_remove(struct platform_device *op)
 122 {
 123         struct uflash_dev *up = dev_get_drvdata(&op->dev);
 124
 125         if (up->mtd) {
 126                 mtd_device_unregister(up->mtd);
 127                 map_destroy(up->mtd);
 128         }
 129         if (up->map.virt) {
 130                 of_iounmap(&op->resource[0], up->map.virt, up->map.size);
 131                 up->map.virt = NULL;
 132         }
 133
 134         kfree(up);
 135 }
 136
 137 static const struct of_device_id uflash_match[] = {
 138         {
 139                 .name = UFLASH_OBPNAME,
 140         },
 141         {},
 142 };
 143
 144 MODULE_DEVICE_TABLE(of, uflash_match);
 145
 146 static struct platform_driver uflash_driver = {
 147         .driver = {
 148                 .name = DRIVER_NAME,
 149                 .of_match_table = uflash_match,
 150         },
 151         .probe          = uflash_probe,
 152         .remove         = uflash_remove,
 153 };
 154
 155 module_platform_driver(uflash_driver);