drivers/mtd/maps/bfin-async-flash.c

   1 /*
   2  * drivers/mtd/maps/bfin-async-flash.c
   3  *
   4  * Handle the case where flash memory and ethernet mac/phy are
   5  * mapped onto the same async bank.  The BF533-STAMP does this
   6  * for example.  All board-specific configuration goes in your
   7  * board resources file.
   8  *
   9  * Copyright 2000 Nicolas Pitre <nico@fluxnic.net>
  10  * Copyright 2005-2008 Analog Devices Inc.
  11  *
  12  * Enter bugs at http://blackfin.uclinux.org/
  13  *
  14  * Licensed under the GPL-2 or later.
  15  */
  16
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/mtd/mtd.h>
  21 #include <linux/mtd/map.h>
  22 #include <linux/mtd/partitions.h>
  23 #include <linux/mtd/physmap.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/slab.h>
  26 #include <linux/types.h>
  27
  28 #include <asm/blackfin.h>
  29 #include <linux/gpio.h>
  30 #include <linux/io.h>
  31 #include <asm/unaligned.h>
  32
  33 #define pr_devinit(fmt, args...) ({ static const __devinitconst char __fmt[] = fmt; printk(__fmt, ## args); })
  34
  35 #define DRIVER_NAME "bfin-async-flash"
  36
  37 struct async_state {
  38         struct mtd_info *mtd;
  39         struct map_info map;
  40         int enet_flash_pin;
  41         uint32_t flash_ambctl0, flash_ambctl1;
  42         uint32_t save_ambctl0, save_ambctl1;
  43         unsigned long irq_flags;
  44 #ifdef CONFIG_MTD_PARTITIONS
  45         struct mtd_partition *parts;
  46 #endif
  47 };
  48
  49 static void switch_to_flash(struct async_state *state)
  50 {
  51         local_irq_save(state->irq_flags);
  52
  53         gpio_set_value(state->enet_flash_pin, 0);
  54
  55         state->save_ambctl0 = bfin_read_EBIU_AMBCTL0();
  56         state->save_ambctl1 = bfin_read_EBIU_AMBCTL1();
  57         bfin_write_EBIU_AMBCTL0(state->flash_ambctl0);
  58         bfin_write_EBIU_AMBCTL1(state->flash_ambctl1);
  59         SSYNC();
  60 }
  61
  62 static void switch_back(struct async_state *state)
  63 {
  64         bfin_write_EBIU_AMBCTL0(state->save_ambctl0);
  65         bfin_write_EBIU_AMBCTL1(state->save_ambctl1);
  66         SSYNC();
  67
  68         gpio_set_value(state->enet_flash_pin, 1);
  69
  70         local_irq_restore(state->irq_flags);
  71 }
  72
  73 static map_word bfin_flash_read(struct map_info *map, unsigned long ofs)
  74 {
  75         struct async_state *state = (struct async_state *)map->map_priv_1;
  76         uint16_t word;
  77         map_word test;
  78
  79         switch_to_flash(state);
  80
  81         word = readw(map->virt + ofs);
  82
  83         switch_back(state);
  84
  85         test.x[0] = word;
  86         return test;
  87 }
  88
  89 static void bfin_flash_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
  90 {
  91         struct async_state *state = (struct async_state *)map->map_priv_1;
  92
  93         switch_to_flash(state);
  94
  95         memcpy(to, map->virt + from, len);
  96
  97         switch_back(state);
  98 }
  99
 100 static void bfin_flash_write(struct map_info *map, map_word d1, unsigned long ofs)
 101 {
 102         struct async_state *state = (struct async_state *)map->map_priv_1;
 103         uint16_t d;
 104
 105         d = d1.x[0];
 106
 107         switch_to_flash(state);
 108
 109         writew(d, map->virt + ofs);
 110         SSYNC();
 111
 112         switch_back(state);
 113 }
 114
 115 static void bfin_flash_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 116 {
 117         struct async_state *state = (struct async_state *)map->map_priv_1;
 118
 119         switch_to_flash(state);
 120
 121         memcpy(map->virt + to, from, len);
 122         SSYNC();
 123
 124         switch_back(state);
 125 }
 126
 127 #ifdef CONFIG_MTD_PARTITIONS
 128 static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
 129 #endif
 130
 131 static int __devinit bfin_flash_probe(struct platform_device *pdev)
 132 {
 133         int ret;
 134         struct physmap_flash_data *pdata = pdev->dev.platform_data;
 135         struct resource *memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 136         struct resource *flash_ambctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 137         struct async_state *state;
 138
 139         state = kzalloc(sizeof(*state), GFP_KERNEL);
 140         if (!state)
 141                 return -ENOMEM;
 142
 143         state->map.name       = DRIVER_NAME;
 144         state->map.read       = bfin_flash_read;
 145         state->map.copy_from  = bfin_flash_copy_from;
 146         state->map.write      = bfin_flash_write;
 147         state->map.copy_to    = bfin_flash_copy_to;
 148         state->map.bankwidth  = pdata->width;
 149         state->map.size       = memory->end - memory->start + 1;
 150         state->map.virt       = (void __iomem *)memory->start;
 151         state->map.phys       = memory->start;
 152         state->map.map_priv_1 = (unsigned long)state;
 153         state->enet_flash_pin = platform_get_irq(pdev, 0);
 154         state->flash_ambctl0  = flash_ambctl->start;
 155         state->flash_ambctl1  = flash_ambctl->end;
 156
 157         if (gpio_request(state->enet_flash_pin, DRIVER_NAME)) {
 158                 pr_devinit(KERN_ERR DRIVER_NAME ": Failed to request gpio %d\n", state->enet_flash_pin);
 159                 kfree(state);
 160                 return -EBUSY;
 161         }
 162         gpio_direction_output(state->enet_flash_pin, 1);
 163
 164         pr_devinit(KERN_NOTICE DRIVER_NAME ": probing %d-bit flash bus\n", state->map.bankwidth * 8);
 165         state->mtd = do_map_probe(memory->name, &state->map);
 166         if (!state->mtd) {
 167                 gpio_free(state->enet_flash_pin);
 168                 kfree(state);
 169                 return -ENXIO;
 170         }
 171
 172 #ifdef CONFIG_MTD_PARTITIONS
 173         ret = parse_mtd_partitions(state->mtd, part_probe_types, &pdata->parts, 0);
 174         if (ret > 0) {
 175                 pr_devinit(KERN_NOTICE DRIVER_NAME ": Using commandline partition definition\n");
 176                 add_mtd_partitions(state->mtd, pdata->parts, ret);
 177                 state->parts = pdata->parts;
 178
 179         } else if (pdata->nr_parts) {
 180                 pr_devinit(KERN_NOTICE DRIVER_NAME ": Using board partition definition\n");
 181                 add_mtd_partitions(state->mtd, pdata->parts, pdata->nr_parts);
 182
 183         } else
 184 #endif
 185         {
 186                 pr_devinit(KERN_NOTICE DRIVER_NAME ": no partition info available, registering whole flash at once\n");
 187                 add_mtd_device(state->mtd);
 188         }
 189
 190         platform_set_drvdata(pdev, state);
 191
 192         return 0;
 193 }
 194
 195 static int __devexit bfin_flash_remove(struct platform_device *pdev)
 196 {
 197         struct async_state *state = platform_get_drvdata(pdev);
 198         gpio_free(state->enet_flash_pin);
 199 #ifdef CONFIG_MTD_PARTITIONS
 200         del_mtd_partitions(state->mtd);
 201         kfree(state->parts);
 202 #endif
 203         map_destroy(state->mtd);
 204         kfree(state);
 205         return 0;
 206 }
 207
 208 static struct platform_driver bfin_flash_driver = {
 209         .probe          = bfin_flash_probe,
 210         .remove         = __devexit_p(bfin_flash_remove),
 211         .driver         = {
 212                 .name   = DRIVER_NAME,
 213         },
 214 };
 215
 216 static int __init bfin_flash_init(void)
 217 {
 218         return platform_driver_register(&bfin_flash_driver);
 219 }
 220 module_init(bfin_flash_init);
 221
 222 static void __exit bfin_flash_exit(void)
 223 {
 224         platform_driver_unregister(&bfin_flash_driver);
 225 }
 226 module_exit(bfin_flash_exit);
 227
 228 MODULE_LICENSE("GPL");
 229 MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");