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