drivers/mtd/maps/intel_vr_nor.c

   1 /*
   2  * drivers/mtd/maps/intel_vr_nor.c
   3  *
   4  * An MTD map driver for a NOR flash bank on the Expansion Bus of the Intel
   5  * Vermilion Range chipset.
   6  *
   7  * The Vermilion Range Expansion Bus supports four chip selects, each of which
   8  * has 64MiB of address space.  The 2nd BAR of the Expansion Bus PCI Device
   9  * is a 256MiB memory region containing the address spaces for all four of the
  10  * chip selects, with start addresses hardcoded on 64MiB boundaries.
  11  *
  12  * This map driver only supports NOR flash on chip select 0.  The buswidth
  13  * (either 8 bits or 16 bits) is determined by reading the Expansion Bus Timing
  14  * and Control Register for Chip Select 0 (EXP_TIMING_CS0).  This driver does
  15  * not modify the value in the EXP_TIMING_CS0 register except to enable writing
  16  * and disable boot acceleration.  The timing parameters in the register are
  17  * assumed to have been properly initialized by the BIOS.  The reset default
  18  * timing parameters are maximally conservative (slow), so access to the flash
  19  * will be slower than it should be if the BIOS has not initialized the timing
  20  * parameters.
  21  *
  22  * Author: Andy Lowe <alowe@mvista.com>
  23  *
  24  * 2006 (c) MontaVista Software, Inc. This file is licensed under
  25  * the terms of the GNU General Public License version 2. This program
  26  * is licensed "as is" without any warranty of any kind, whether express
  27  * or implied.
  28  */
  29
  30 #include <linux/module.h>
  31 #include <linux/kernel.h>
  32 #include <linux/slab.h>
  33 #include <linux/pci.h>
  34 #include <linux/mtd/mtd.h>
  35 #include <linux/mtd/map.h>
  36 #include <linux/mtd/partitions.h>
  37 #include <linux/mtd/cfi.h>
  38 #include <linux/mtd/flashchip.h>
  39
  40 #define DRV_NAME "vr_nor"
  41
  42 struct vr_nor_mtd {
  43         void __iomem *csr_base;
  44         struct map_info map;
  45         struct mtd_info *info;
  46         struct pci_dev *dev;
  47 };
  48
  49 /* Expansion Bus Configuration and Status Registers are in BAR 0 */
  50 #define EXP_CSR_MBAR 0
  51 /* Expansion Bus Memory Window is BAR 1 */
  52 #define EXP_WIN_MBAR 1
  53 /* Maximum address space for Chip Select 0 is 64MiB */
  54 #define CS0_SIZE 0x04000000
  55 /* Chip Select 0 is at offset 0 in the Memory Window */
  56 #define CS0_START 0x0
  57 /* Chip Select 0 Timing Register is at offset 0 in CSR */
  58 #define EXP_TIMING_CS0 0x00
  59 #define TIMING_CS_EN            (1 << 31)       /* Chip Select Enable */
  60 #define TIMING_BOOT_ACCEL_DIS   (1 <<  8)       /* Boot Acceleration Disable */
  61 #define TIMING_WR_EN            (1 <<  1)       /* Write Enable */
  62 #define TIMING_BYTE_EN          (1 <<  0)       /* 8-bit vs 16-bit bus */
  63 #define TIMING_MASK             0x3FFF0000
  64
  65 static void vr_nor_destroy_partitions(struct vr_nor_mtd *p)
  66 {
  67         mtd_device_unregister(p->info);
  68 }
  69
  70 static int vr_nor_init_partitions(struct vr_nor_mtd *p)
  71 {
  72         /* register the flash bank */
  73         /* partition the flash bank */
  74         return mtd_device_parse_register(p->info, NULL, NULL, NULL, 0);
  75 }
  76
  77 static void vr_nor_destroy_mtd_setup(struct vr_nor_mtd *p)
  78 {
  79         map_destroy(p->info);
  80 }
  81
  82 static int vr_nor_mtd_setup(struct vr_nor_mtd *p)
  83 {
  84         static const char * const probe_types[] =
  85             { "cfi_probe", "jedec_probe", NULL };
  86         const char * const *type;
  87
  88         for (type = probe_types; !p->info && *type; type++)
  89                 p->info = do_map_probe(*type, &p->map);
  90         if (!p->info)
  91                 return -ENODEV;
  92
  93         p->info->owner = THIS_MODULE;
  94
  95         return 0;
  96 }
  97
  98 static void vr_nor_destroy_maps(struct vr_nor_mtd *p)
  99 {
 100         unsigned int exp_timing_cs0;
 101
 102         /* write-protect the flash bank */
 103         exp_timing_cs0 = readl(p->csr_base + EXP_TIMING_CS0);
 104         exp_timing_cs0 &= ~TIMING_WR_EN;
 105         writel(exp_timing_cs0, p->csr_base + EXP_TIMING_CS0);
 106
 107         /* unmap the flash window */
 108         iounmap(p->map.virt);
 109
 110         /* unmap the csr window */
 111         iounmap(p->csr_base);
 112 }
 113
 114 /*
 115  * Initialize the map_info structure and map the flash.
 116  * Returns 0 on success, nonzero otherwise.
 117  */
 118 static int vr_nor_init_maps(struct vr_nor_mtd *p)
 119 {
 120         unsigned long csr_phys, csr_len;
 121         unsigned long win_phys, win_len;
 122         unsigned int exp_timing_cs0;
 123         int err;
 124
 125         csr_phys = pci_resource_start(p->dev, EXP_CSR_MBAR);
 126         csr_len = pci_resource_len(p->dev, EXP_CSR_MBAR);
 127         win_phys = pci_resource_start(p->dev, EXP_WIN_MBAR);
 128         win_len = pci_resource_len(p->dev, EXP_WIN_MBAR);
 129
 130         if (!csr_phys || !csr_len || !win_phys || !win_len)
 131                 return -ENODEV;
 132
 133         if (win_len < (CS0_START + CS0_SIZE))
 134                 return -ENXIO;
 135
 136         p->csr_base = ioremap_nocache(csr_phys, csr_len);
 137         if (!p->csr_base)
 138                 return -ENOMEM;
 139
 140         exp_timing_cs0 = readl(p->csr_base + EXP_TIMING_CS0);
 141         if (!(exp_timing_cs0 & TIMING_CS_EN)) {
 142                 dev_warn(&p->dev->dev, "Expansion Bus Chip Select 0 "
 143                        "is disabled.\n");
 144                 err = -ENODEV;
 145                 goto release;
 146         }
 147         if ((exp_timing_cs0 & TIMING_MASK) == TIMING_MASK) {
 148                 dev_warn(&p->dev->dev, "Expansion Bus Chip Select 0 "
 149                        "is configured for maximally slow access times.\n");
 150         }
 151         p->map.name = DRV_NAME;
 152         p->map.bankwidth = (exp_timing_cs0 & TIMING_BYTE_EN) ? 1 : 2;
 153         p->map.phys = win_phys + CS0_START;
 154         p->map.size = CS0_SIZE;
 155         p->map.virt = ioremap_nocache(p->map.phys, p->map.size);
 156         if (!p->map.virt) {
 157                 err = -ENOMEM;
 158                 goto release;
 159         }
 160         simple_map_init(&p->map);
 161
 162         /* Enable writes to flash bank */
 163         exp_timing_cs0 |= TIMING_BOOT_ACCEL_DIS | TIMING_WR_EN;
 164         writel(exp_timing_cs0, p->csr_base + EXP_TIMING_CS0);
 165
 166         return 0;
 167
 168       release:
 169         iounmap(p->csr_base);
 170         return err;
 171 }
 172
 173 static struct pci_device_id vr_nor_pci_ids[] = {
 174         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x500D)},
 175         {0,}
 176 };
 177
 178 static void vr_nor_pci_remove(struct pci_dev *dev)
 179 {
 180         struct vr_nor_mtd *p = pci_get_drvdata(dev);
 181
 182         vr_nor_destroy_partitions(p);
 183         vr_nor_destroy_mtd_setup(p);
 184         vr_nor_destroy_maps(p);
 185         kfree(p);
 186         pci_release_regions(dev);
 187         pci_disable_device(dev);
 188 }
 189
 190 static int vr_nor_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 191 {
 192         struct vr_nor_mtd *p = NULL;
 193         unsigned int exp_timing_cs0;
 194         int err;
 195
 196         err = pci_enable_device(dev);
 197         if (err)
 198                 goto out;
 199
 200         err = pci_request_regions(dev, DRV_NAME);
 201         if (err)
 202                 goto disable_dev;
 203
 204         p = kzalloc(sizeof(*p), GFP_KERNEL);
 205         err = -ENOMEM;
 206         if (!p)
 207                 goto release;
 208
 209         p->dev = dev;
 210
 211         err = vr_nor_init_maps(p);
 212         if (err)
 213                 goto release;
 214
 215         err = vr_nor_mtd_setup(p);
 216         if (err)
 217                 goto destroy_maps;
 218
 219         err = vr_nor_init_partitions(p);
 220         if (err)
 221                 goto destroy_mtd_setup;
 222
 223         pci_set_drvdata(dev, p);
 224
 225         return 0;
 226
 227       destroy_mtd_setup:
 228         map_destroy(p->info);
 229
 230       destroy_maps:
 231         /* write-protect the flash bank */
 232         exp_timing_cs0 = readl(p->csr_base + EXP_TIMING_CS0);
 233         exp_timing_cs0 &= ~TIMING_WR_EN;
 234         writel(exp_timing_cs0, p->csr_base + EXP_TIMING_CS0);
 235
 236         /* unmap the flash window */
 237         iounmap(p->map.virt);
 238
 239         /* unmap the csr window */
 240         iounmap(p->csr_base);
 241
 242       release:
 243         kfree(p);
 244         pci_release_regions(dev);
 245
 246       disable_dev:
 247         pci_disable_device(dev);
 248
 249       out:
 250         return err;
 251 }
 252
 253 static struct pci_driver vr_nor_pci_driver = {
 254         .name = DRV_NAME,
 255         .probe = vr_nor_pci_probe,
 256         .remove = vr_nor_pci_remove,
 257         .id_table = vr_nor_pci_ids,
 258 };
 259
 260 module_pci_driver(vr_nor_pci_driver);
 261
 262 MODULE_AUTHOR("Andy Lowe");
 263 MODULE_DESCRIPTION("MTD map driver for NOR flash on Intel Vermilion Range");
 264 MODULE_LICENSE("GPL");
 265 MODULE_DEVICE_TABLE(pci, vr_nor_pci_ids);