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...) \
  34                 ({ static const char __fmt[] = fmt; printk(__fmt, ## args); })
  35
  36 #define DRIVER_NAME "bfin-async-flash"
  37
  38 struct async_state {
  39         struct mtd_info *mtd;
  40         struct map_info map;
  41         int enet_flash_pin;
  42         uint32_t flash_ambctl0, flash_ambctl1;
  43         uint32_t save_ambctl0, save_ambctl1;
  44         unsigned long irq_flags;
  45 };
  46
  47 static void switch_to_flash(struct async_state *state)
  48 {
  49         local_irq_save(state->irq_flags);
  50
  51         gpio_set_value(state->enet_flash_pin, 0);
  52
  53         state->save_ambctl0 = bfin_read_EBIU_AMBCTL0();
  54         state->save_ambctl1 = bfin_read_EBIU_AMBCTL1();
  55         bfin_write_EBIU_AMBCTL0(state->flash_ambctl0);
  56         bfin_write_EBIU_AMBCTL1(state->flash_ambctl1);
  57         SSYNC();
  58 }
  59
  60 static void switch_back(struct async_state *state)
  61 {
  62         bfin_write_EBIU_AMBCTL0(state->save_ambctl0);
  63         bfin_write_EBIU_AMBCTL1(state->save_ambctl1);
  64         SSYNC();
  65
  66         gpio_set_value(state->enet_flash_pin, 1);
  67
  68         local_irq_restore(state->irq_flags);
  69 }
  70
  71 static map_word bfin_flash_read(struct map_info *map, unsigned long ofs)
  72 {
  73         struct async_state *state = (struct async_state *)map->map_priv_1;
  74         uint16_t word;
  75         map_word test;
  76
  77         switch_to_flash(state);
  78
  79         word = readw(map->virt + ofs);
  80
  81         switch_back(state);
  82
  83         test.x[0] = word;
  84         return test;
  85 }
  86
  87 static void bfin_flash_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
  88 {
  89         struct async_state *state = (struct async_state *)map->map_priv_1;
  90
  91         switch_to_flash(state);
  92
  93         memcpy(to, map->virt + from, len);
  94
  95         switch_back(state);
  96 }
  97
  98 static void bfin_flash_write(struct map_info *map, map_word d1, unsigned long ofs)
  99 {
 100         struct async_state *state = (struct async_state *)map->map_priv_1;
 101         uint16_t d;
 102
 103         d = d1.x[0];
 104
 105         switch_to_flash(state);
 106
 107         writew(d, map->virt + ofs);
 108         SSYNC();
 109
 110         switch_back(state);
 111 }
 112
 113 static void bfin_flash_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
 114 {
 115         struct async_state *state = (struct async_state *)map->map_priv_1;
 116
 117         switch_to_flash(state);
 118
 119         memcpy(map->virt + to, from, len);
 120         SSYNC();
 121
 122         switch_back(state);
 123 }
 124
 125 static const char * const part_probe_types[] = {
 126         "cmdlinepart", "RedBoot", NULL };
 127
 128 static int bfin_flash_probe(struct platform_device *pdev)
 129 {
 130         int ret;
 131         struct physmap_flash_data *pdata = dev_get_platdata(&pdev->dev);
 132         struct resource *memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 133         struct resource *flash_ambctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 134         struct async_state *state;
 135
 136         state = kzalloc(sizeof(*state), GFP_KERNEL);
 137         if (!state)
 138                 return -ENOMEM;
 139
 140         state->map.name       = DRIVER_NAME;
 141         state->map.read       = bfin_flash_read;
 142         state->map.copy_from  = bfin_flash_copy_from;
 143         state->map.write      = bfin_flash_write;
 144         state->map.copy_to    = bfin_flash_copy_to;
 145         state->map.bankwidth  = pdata->width;
 146         state->map.size       = resource_size(memory);
 147         state->map.virt       = (void __iomem *)memory->start;
 148         state->map.phys       = memory->start;
 149         state->map.map_priv_1 = (unsigned long)state;
 150         state->enet_flash_pin = platform_get_irq(pdev, 0);
 151         state->flash_ambctl0  = flash_ambctl->start;
 152         state->flash_ambctl1  = flash_ambctl->end;
 153
 154         if (gpio_request(state->enet_flash_pin, DRIVER_NAME)) {
 155                 pr_devinit(KERN_ERR DRIVER_NAME ": Failed to request gpio %d\n", state->enet_flash_pin);
 156                 kfree(state);
 157                 return -EBUSY;
 158         }
 159         gpio_direction_output(state->enet_flash_pin, 1);
 160
 161         pr_devinit(KERN_NOTICE DRIVER_NAME ": probing %d-bit flash bus\n", state->map.bankwidth * 8);
 162         state->mtd = do_map_probe(memory->name, &state->map);
 163         if (!state->mtd) {
 164                 gpio_free(state->enet_flash_pin);
 165                 kfree(state);
 166                 return -ENXIO;
 167         }
 168
 169         mtd_device_parse_register(state->mtd, part_probe_types, NULL,
 170                                   pdata->parts, pdata->nr_parts);
 171
 172         platform_set_drvdata(pdev, state);
 173
 174         return 0;
 175 }
 176
 177 static int bfin_flash_remove(struct platform_device *pdev)
 178 {
 179         struct async_state *state = platform_get_drvdata(pdev);
 180         gpio_free(state->enet_flash_pin);
 181         mtd_device_unregister(state->mtd);
 182         map_destroy(state->mtd);
 183         kfree(state);
 184         return 0;
 185 }
 186
 187 static struct platform_driver bfin_flash_driver = {
 188         .probe          = bfin_flash_probe,
 189         .remove         = bfin_flash_remove,
 190         .driver         = {
 191                 .name   = DRIVER_NAME,
 192         },
 193 };
 194
 195 module_platform_driver(bfin_flash_driver);
 196
 197 MODULE_LICENSE("GPL");
 198 MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");