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