target/linux/lantiq/patches-2.6.32/0004-MIPS-Lantiq-Add-NOR-flash-support.patch

   1 From cd0d53b24ca744295d2cdf69bb2b659571091b75 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Tue, 12 Apr 2011 18:10:01 +0200
   4 Subject: [PATCH 04/13] MIPS: Lantiq: Add NOR flash support
   5
   6 This patch adds the driver/map for NOR devices attached to the SoC via the
   7 External Bus Unit (EBU).
   8
   9 Signed-off-by: John Crispin <blogic@openwrt.org>
  10 Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
  11 Cc: David Woodhouse <dwmw2@infradead.org>
  12 Cc: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>
  13 Cc: linux-mips@linux-mips.org
  14 Cc: linux-mtd@lists.infradead.org
  15 Acked-by: Artem Bityutskiy <dedekind1@gmail.com>
  16 Patchwork: https://patchwork.linux-mips.org/patch/2285/
  17 Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
  18 ---
  19  drivers/mtd/maps/Kconfig        |    7 +
  20  drivers/mtd/maps/Makefile       |    1 +
  21  drivers/mtd/maps/lantiq-flash.c |  251 +++++++++++++++++++++++++++++++++++++++
  22  3 files changed, 259 insertions(+), 0 deletions(-)
  23  create mode 100644 drivers/mtd/maps/lantiq-flash.c
  24
  25 --- a/drivers/mtd/maps/Kconfig
  26 +++ b/drivers/mtd/maps/Kconfig
  27 @@ -259,6 +259,13 @@
  28         help
  29           Flash memory access on AMD Alchemy Pb/Db/RDK Reference Boards
  30
  31 +config MTD_LANTIQ
  32 +       tristate "Lantiq SoC NOR support"
  33 +       depends on LANTIQ
  34 +       select MTD_PARTITIONS
  35 +       help
  36 +         Support for NOR flash attached to the Lantiq SoC's External Bus Unit.
  37 +
  38  config MTD_DILNETPC
  39         tristate "CFI Flash device mapped on DIL/Net PC"
  40         depends on X86 && MTD_CONCAT && MTD_PARTITIONS && MTD_CFI_INTELEXT && BROKEN
  41 --- a/drivers/mtd/maps/Makefile
  42 +++ b/drivers/mtd/maps/Makefile
  43 @@ -61,3 +61,4 @@
  44  obj-$(CONFIG_MTD_RBTX4939)     += rbtx4939-flash.o
  45  obj-$(CONFIG_MTD_VMU)          += vmu-flash.o
  46  obj-$(CONFIG_MTD_GPIO_ADDR)    += gpio-addr-flash.o
  47 +obj-$(CONFIG_MTD_LANTIQ)       += lantiq-flash.o
  48 --- /dev/null
  49 +++ b/drivers/mtd/maps/lantiq-flash.c
  50 @@ -0,0 +1,251 @@
  51 +/*
  52 + *  This program is free software; you can redistribute it and/or modify it
  53 + *  under the terms of the GNU General Public License version 2 as published
  54 + *  by the Free Software Foundation.
  55 + *
  56 + *  Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
  57 + *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
  58 + */
  59 +
  60 +#include <linux/module.h>
  61 +#include <linux/types.h>
  62 +#include <linux/kernel.h>
  63 +#include <linux/io.h>
  64 +#include <linux/slab.h>
  65 +#include <linux/init.h>
  66 +#include <linux/mtd/mtd.h>
  67 +#include <linux/mtd/map.h>
  68 +#include <linux/mtd/partitions.h>
  69 +#include <linux/mtd/cfi.h>
  70 +#include <linux/platform_device.h>
  71 +#include <linux/mtd/physmap.h>
  72 +
  73 +#include <lantiq_soc.h>
  74 +#include <lantiq_platform.h>
  75 +
  76 +/*
  77 + * The NOR flash is connected to the same external bus unit (EBU) as PCI.
  78 + * To make PCI work we need to enable the endianness swapping for the address
  79 + * written to the EBU. This endianness swapping works for PCI correctly but
  80 + * fails for attached NOR devices. To workaround this we need to use a complex
  81 + * map. The workaround involves swapping all addresses whilst probing the chip.
  82 + * Once probing is complete we stop swapping the addresses but swizzle the
  83 + * unlock addresses to ensure that access to the NOR device works correctly.
  84 + */
  85 +
  86 +enum {
  87 +       LTQ_NOR_PROBING,
  88 +       LTQ_NOR_NORMAL
  89 +};
  90 +
  91 +struct ltq_mtd {
  92 +       struct resource *res;
  93 +       struct mtd_info *mtd;
  94 +       struct map_info *map;
  95 +};
  96 +
  97 +static char ltq_map_name[] = "ltq_nor";
  98 +
  99 +static map_word
 100 +ltq_read16(struct map_info *map, unsigned long adr)
 101 +{
 102 +       unsigned long flags;
 103 +       map_word temp;
 104 +
 105 +       if (map->map_priv_1 == LTQ_NOR_PROBING)
 106 +               adr ^= 2;
 107 +       spin_lock_irqsave(&ebu_lock, flags);
 108 +       temp.x[0] = *(u16 *)(map->virt + adr);
 109 +       spin_unlock_irqrestore(&ebu_lock, flags);
 110 +       return temp;
 111 +}
 112 +
 113 +static void
 114 +ltq_write16(struct map_info *map, map_word d, unsigned long adr)
 115 +{
 116 +       unsigned long flags;
 117 +
 118 +       if (map->map_priv_1 == LTQ_NOR_PROBING)
 119 +               adr ^= 2;
 120 +       spin_lock_irqsave(&ebu_lock, flags);
 121 +       *(u16 *)(map->virt + adr) = d.x[0];
 122 +       spin_unlock_irqrestore(&ebu_lock, flags);
 123 +}
 124 +
 125 +/*
 126 + * The following 2 functions copy data between iomem and a cached memory
 127 + * section. As memcpy() makes use of pre-fetching we cannot use it here.
 128 + * The normal alternative of using memcpy_{to,from}io also makes use of
 129 + * memcpy() on MIPS so it is not applicable either. We are therefore stuck
 130 + * with having to use our own loop.
 131 + */
 132 +static void
 133 +ltq_copy_from(struct map_info *map, void *to,
 134 +       unsigned long from, ssize_t len)
 135 +{
 136 +       unsigned char *f = (unsigned char *)map->virt + from;
 137 +       unsigned char *t = (unsigned char *)to;
 138 +       unsigned long flags;
 139 +
 140 +       spin_lock_irqsave(&ebu_lock, flags);
 141 +       while (len--)
 142 +               *t++ = *f++;
 143 +       spin_unlock_irqrestore(&ebu_lock, flags);
 144 +}
 145 +
 146 +static void
 147 +ltq_copy_to(struct map_info *map, unsigned long to,
 148 +       const void *from, ssize_t len)
 149 +{
 150 +       unsigned char *f = (unsigned char *)from;
 151 +       unsigned char *t = (unsigned char *)map->virt + to;
 152 +       unsigned long flags;
 153 +
 154 +       spin_lock_irqsave(&ebu_lock, flags);
 155 +       while (len--)
 156 +               *t++ = *f++;
 157 +       spin_unlock_irqrestore(&ebu_lock, flags);
 158 +}
 159 +
 160 +static const char const *part_probe_types[] = { "cmdlinepart", NULL };
 161 +
 162 +static int __init
 163 +ltq_mtd_probe(struct platform_device *pdev)
 164 +{
 165 +       struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev);
 166 +       struct ltq_mtd *ltq_mtd;
 167 +       struct mtd_partition *parts;
 168 +       struct resource *res;
 169 +       int nr_parts = 0;
 170 +       struct cfi_private *cfi;
 171 +       int err;
 172 +
 173 +       ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
 174 +       platform_set_drvdata(pdev, ltq_mtd);
 175 +
 176 +       ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 177 +       if (!ltq_mtd->res) {
 178 +               dev_err(&pdev->dev, "failed to get memory resource");
 179 +               err = -ENOENT;
 180 +               goto err_out;
 181 +       }
 182 +
 183 +       res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start,
 184 +               resource_size(ltq_mtd->res), dev_name(&pdev->dev));
 185 +       if (!ltq_mtd->res) {
 186 +               dev_err(&pdev->dev, "failed to request mem resource");
 187 +               err = -EBUSY;
 188 +               goto err_out;
 189 +       }
 190 +
 191 +       ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
 192 +       ltq_mtd->map->phys = res->start;
 193 +       ltq_mtd->map->size = resource_size(res);
 194 +       ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev,
 195 +                               ltq_mtd->map->phys, ltq_mtd->map->size);
 196 +       if (!ltq_mtd->map->virt) {
 197 +               dev_err(&pdev->dev, "failed to ioremap!\n");
 198 +               err = -ENOMEM;
 199 +               goto err_free;
 200 +       }
 201 +
 202 +       ltq_mtd->map->name = ltq_map_name;
 203 +       ltq_mtd->map->bankwidth = 2;
 204 +       ltq_mtd->map->read = ltq_read16;
 205 +       ltq_mtd->map->write = ltq_write16;
 206 +       ltq_mtd->map->copy_from = ltq_copy_from;
 207 +       ltq_mtd->map->copy_to = ltq_copy_to;
 208 +
 209 +       ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
 210 +       ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
 211 +       ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
 212 +
 213 +       if (!ltq_mtd->mtd) {
 214 +               dev_err(&pdev->dev, "probing failed\n");
 215 +               err = -ENXIO;
 216 +               goto err_unmap;
 217 +       }
 218 +
 219 +       ltq_mtd->mtd->owner = THIS_MODULE;
 220 +
 221 +       cfi = ltq_mtd->map->fldrv_priv;
 222 +       cfi->addr_unlock1 ^= 1;
 223 +       cfi->addr_unlock2 ^= 1;
 224 +
 225 +       nr_parts = parse_mtd_partitions(ltq_mtd->mtd,
 226 +                               part_probe_types, &parts, 0);
 227 +       if (nr_parts > 0) {
 228 +               dev_info(&pdev->dev,
 229 +                       "using %d partitions from cmdline", nr_parts);
 230 +       } else {
 231 +               nr_parts = ltq_mtd_data->nr_parts;
 232 +               parts = ltq_mtd_data->parts;
 233 +       }
 234 +
 235 +       err = add_mtd_partitions(ltq_mtd->mtd, parts, nr_parts);
 236 +       if (err) {
 237 +               dev_err(&pdev->dev, "failed to add partitions\n");
 238 +               goto err_destroy;
 239 +       }
 240 +
 241 +       return 0;
 242 +
 243 +err_destroy:
 244 +       map_destroy(ltq_mtd->mtd);
 245 +err_unmap:
 246 +       iounmap(ltq_mtd->map->virt);
 247 +err_free:
 248 +       kfree(ltq_mtd->map);
 249 +err_out:
 250 +       kfree(ltq_mtd);
 251 +       return err;
 252 +}
 253 +
 254 +static int __devexit
 255 +ltq_mtd_remove(struct platform_device *pdev)
 256 +{
 257 +       struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
 258 +
 259 +       if (ltq_mtd) {
 260 +               if (ltq_mtd->mtd) {
 261 +                       del_mtd_partitions(ltq_mtd->mtd);
 262 +                       map_destroy(ltq_mtd->mtd);
 263 +               }
 264 +               if (ltq_mtd->map->virt)
 265 +                       iounmap(ltq_mtd->map->virt);
 266 +               kfree(ltq_mtd->map);
 267 +               kfree(ltq_mtd);
 268 +       }
 269 +       return 0;
 270 +}
 271 +
 272 +static struct platform_driver ltq_mtd_driver = {
 273 +       .remove = __devexit_p(ltq_mtd_remove),
 274 +       .driver = {
 275 +               .name = "ltq_nor",
 276 +               .owner = THIS_MODULE,
 277 +       },
 278 +};
 279 +
 280 +static int __init
 281 +init_ltq_mtd(void)
 282 +{
 283 +       int ret = platform_driver_probe(&ltq_mtd_driver, ltq_mtd_probe);
 284 +
 285 +       if (ret)
 286 +               pr_err("ltq_nor: error registering platform driver");
 287 +       return ret;
 288 +}
 289 +
 290 +static void __exit
 291 +exit_ltq_mtd(void)
 292 +{
 293 +       platform_driver_unregister(&ltq_mtd_driver);
 294 +}
 295 +
 296 +module_init(init_ltq_mtd);
 297 +module_exit(exit_ltq_mtd);
 298 +
 299 +MODULE_LICENSE("GPL");
 300 +MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
 301 +MODULE_DESCRIPTION("Lantiq SoC NOR");