kernel/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/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/mtd/mtd.h>
  20 #include <linux/mtd/map.h>
  21 #include <linux/mtd/partitions.h>
  22 #include <linux/mtd/physmap.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/slab.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...) \
  33                 ({ static const 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 };
  45
  46 static void switch_to_flash(struct async_state *state)
  47 {
  48         local_irq_save(state->irq_flags);
  49
  50         gpio_set_value(state->enet_flash_pin, 0);
  51
  52         state->save_ambctl0 = bfin_read_EBIU_AMBCTL0();
  53         state->save_ambctl1 = bfin_read_EBIU_AMBCTL1();
  54         bfin_write_EBIU_AMBCTL0(state->flash_ambctl0);
  55         bfin_write_EBIU_AMBCTL1(state->flash_ambctl1);
  56         SSYNC();
  57 }
  58
  59 static void switch_back(struct async_state *state)
  60 {
  61         bfin_write_EBIU_AMBCTL0(state->save_ambctl0);
  62         bfin_write_EBIU_AMBCTL1(state->save_ambctl1);
  63         SSYNC();
  64
  65         gpio_set_value(state->enet_flash_pin, 1);
  66
  67         local_irq_restore(state->irq_flags);
  68 }
  69
  70 static map_word bfin_flash_read(struct map_info *map, unsigned long ofs)
  71 {
  72         struct async_state *state = (struct async_state *)map->map_priv_1;
  73         uint16_t word;
  74         map_word test;
  75
  76         switch_to_flash(state);
  77
  78         word = readw(map->virt + ofs);
  79
  80         switch_back(state);
  81
  82         test.x[0] = word;
  83         return test;
  84 }
  85
  86 static void bfin_flash_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
  87 {
  88         struct async_state *state = (struct async_state *)map->map_priv_1;
  89
  90         switch_to_flash(state);
  91
  92         memcpy(to, map->virt + from, len);
  93
  94         switch_back(state);
  95 }
  96
  97 static void bfin_flash_write(struct map_info *map, map_word d1, unsigned long ofs)
  98 {
  99         struct async_state *state = (struct async_state *)map->map_priv_1;
 100         uint16_t d;
 101
 102         d = d1.x[0];
 103
 104         switch_to_flash(state);
 105
 106         writew(d, map->virt + ofs);
 107         SSYNC();
 108
 109         switch_back(state);
 110 }
 111
 112 static void bfin_flash_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 113 {
 114         struct async_state *state = (struct async_state *)map->map_priv_1;
 115
 116         switch_to_flash(state);
 117
 118         memcpy(map->virt + to, from, len);
 119         SSYNC();
 120
 121         switch_back(state);
 122 }
 123
 124 static const char * const part_probe_types[] = {
 125         "cmdlinepart", "RedBoot", NULL };
 126
 127 static int bfin_flash_probe(struct platform_device *pdev)
 128 {
 129         struct physmap_flash_data *pdata = dev_get_platdata(&pdev->dev);
 130         struct resource *memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 131         struct resource *flash_ambctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 132         struct async_state *state;
 133
 134         state = kzalloc(sizeof(*state), GFP_KERNEL);
 135         if (!state)
 136                 return -ENOMEM;
 137
 138         state->map.name       = DRIVER_NAME;
 139         state->map.read       = bfin_flash_read;
 140         state->map.copy_from  = bfin_flash_copy_from;
 141         state->map.write      = bfin_flash_write;
 142         state->map.copy_to    = bfin_flash_copy_to;
 143         state->map.bankwidth  = pdata->width;
 144         state->map.size       = resource_size(memory);
 145         state->map.virt       = (void __iomem *)memory->start;
 146         state->map.phys       = memory->start;
 147         state->map.map_priv_1 = (unsigned long)state;
 148         state->enet_flash_pin = platform_get_irq(pdev, 0);
 149         state->flash_ambctl0  = flash_ambctl->start;
 150         state->flash_ambctl1  = flash_ambctl->end;
 151
 152         if (gpio_request(state->enet_flash_pin, DRIVER_NAME)) {
 153                 pr_devinit(KERN_ERR DRIVER_NAME ": Failed to request gpio %d\n", state->enet_flash_pin);
 154                 kfree(state);
 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                 gpio_free(state->enet_flash_pin);
 163                 kfree(state);
 164                 return -ENXIO;
 165         }
 166
 167         mtd_device_parse_register(state->mtd, part_probe_types, NULL,
 168                                   pdata->parts, pdata->nr_parts);
 169
 170         platform_set_drvdata(pdev, state);
 171
 172         return 0;
 173 }
 174
 175 static int bfin_flash_remove(struct platform_device *pdev)
 176 {
 177         struct async_state *state = platform_get_drvdata(pdev);
 178         gpio_free(state->enet_flash_pin);
 179         mtd_device_unregister(state->mtd);
 180         map_destroy(state->mtd);
 181         kfree(state);
 182         return 0;
 183 }
 184
 185 static struct platform_driver bfin_flash_driver = {
 186         .probe          = bfin_flash_probe,
 187         .remove         = bfin_flash_remove,
 188         .driver         = {
 189                 .name   = DRIVER_NAME,
 190         },
 191 };
 192
 193 module_platform_driver(bfin_flash_driver);
 194
 195 MODULE_LICENSE("GPL");
 196 MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");