OpenCloudOS-Kernel/drivers/mtd/maps/intel_vr_nor.c

266 lines
6.8 KiB
C

/*
* drivers/mtd/maps/intel_vr_nor.c
*
* An MTD map driver for a NOR flash bank on the Expansion Bus of the Intel
* Vermilion Range chipset.
*
* The Vermilion Range Expansion Bus supports four chip selects, each of which
* has 64MiB of address space. The 2nd BAR of the Expansion Bus PCI Device
* is a 256MiB memory region containing the address spaces for all four of the
* chip selects, with start addresses hardcoded on 64MiB boundaries.
*
* This map driver only supports NOR flash on chip select 0. The buswidth
* (either 8 bits or 16 bits) is determined by reading the Expansion Bus Timing
* and Control Register for Chip Select 0 (EXP_TIMING_CS0). This driver does
* not modify the value in the EXP_TIMING_CS0 register except to enable writing
* and disable boot acceleration. The timing parameters in the register are
* assumed to have been properly initialized by the BIOS. The reset default
* timing parameters are maximally conservative (slow), so access to the flash
* will be slower than it should be if the BIOS has not initialized the timing
* parameters.
*
* Author: Andy Lowe <alowe@mvista.com>
*
* 2006 (c) MontaVista Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/cfi.h>
#include <linux/mtd/flashchip.h>
#define DRV_NAME "vr_nor"
struct vr_nor_mtd {
void __iomem *csr_base;
struct map_info map;
struct mtd_info *info;
struct pci_dev *dev;
};
/* Expansion Bus Configuration and Status Registers are in BAR 0 */
#define EXP_CSR_MBAR 0
/* Expansion Bus Memory Window is BAR 1 */
#define EXP_WIN_MBAR 1
/* Maximum address space for Chip Select 0 is 64MiB */
#define CS0_SIZE 0x04000000
/* Chip Select 0 is at offset 0 in the Memory Window */
#define CS0_START 0x0
/* Chip Select 0 Timing Register is at offset 0 in CSR */
#define EXP_TIMING_CS0 0x00
#define TIMING_CS_EN (1 << 31) /* Chip Select Enable */
#define TIMING_BOOT_ACCEL_DIS (1 << 8) /* Boot Acceleration Disable */
#define TIMING_WR_EN (1 << 1) /* Write Enable */
#define TIMING_BYTE_EN (1 << 0) /* 8-bit vs 16-bit bus */
#define TIMING_MASK 0x3FFF0000
static void vr_nor_destroy_partitions(struct vr_nor_mtd *p)
{
mtd_device_unregister(p->info);
}
static int vr_nor_init_partitions(struct vr_nor_mtd *p)
{
/* register the flash bank */
/* partition the flash bank */
return mtd_device_parse_register(p->info, NULL, NULL, NULL, 0);
}
static void vr_nor_destroy_mtd_setup(struct vr_nor_mtd *p)
{
map_destroy(p->info);
}
static int vr_nor_mtd_setup(struct vr_nor_mtd *p)
{
static const char * const probe_types[] =
{ "cfi_probe", "jedec_probe", NULL };
const char * const *type;
for (type = probe_types; !p->info && *type; type++)
p->info = do_map_probe(*type, &p->map);
if (!p->info)
return -ENODEV;
p->info->dev.parent = &p->dev->dev;
return 0;
}
static void vr_nor_destroy_maps(struct vr_nor_mtd *p)
{
unsigned int exp_timing_cs0;
/* write-protect the flash bank */
exp_timing_cs0 = readl(p->csr_base + EXP_TIMING_CS0);
exp_timing_cs0 &= ~TIMING_WR_EN;
writel(exp_timing_cs0, p->csr_base + EXP_TIMING_CS0);
/* unmap the flash window */
iounmap(p->map.virt);
/* unmap the csr window */
iounmap(p->csr_base);
}
/*
* Initialize the map_info structure and map the flash.
* Returns 0 on success, nonzero otherwise.
*/
static int vr_nor_init_maps(struct vr_nor_mtd *p)
{
unsigned long csr_phys, csr_len;
unsigned long win_phys, win_len;
unsigned int exp_timing_cs0;
int err;
csr_phys = pci_resource_start(p->dev, EXP_CSR_MBAR);
csr_len = pci_resource_len(p->dev, EXP_CSR_MBAR);
win_phys = pci_resource_start(p->dev, EXP_WIN_MBAR);
win_len = pci_resource_len(p->dev, EXP_WIN_MBAR);
if (!csr_phys || !csr_len || !win_phys || !win_len)
return -ENODEV;
if (win_len < (CS0_START + CS0_SIZE))
return -ENXIO;
p->csr_base = ioremap_nocache(csr_phys, csr_len);
if (!p->csr_base)
return -ENOMEM;
exp_timing_cs0 = readl(p->csr_base + EXP_TIMING_CS0);
if (!(exp_timing_cs0 & TIMING_CS_EN)) {
dev_warn(&p->dev->dev, "Expansion Bus Chip Select 0 "
"is disabled.\n");
err = -ENODEV;
goto release;
}
if ((exp_timing_cs0 & TIMING_MASK) == TIMING_MASK) {
dev_warn(&p->dev->dev, "Expansion Bus Chip Select 0 "
"is configured for maximally slow access times.\n");
}
p->map.name = DRV_NAME;
p->map.bankwidth = (exp_timing_cs0 & TIMING_BYTE_EN) ? 1 : 2;
p->map.phys = win_phys + CS0_START;
p->map.size = CS0_SIZE;
p->map.virt = ioremap_nocache(p->map.phys, p->map.size);
if (!p->map.virt) {
err = -ENOMEM;
goto release;
}
simple_map_init(&p->map);
/* Enable writes to flash bank */
exp_timing_cs0 |= TIMING_BOOT_ACCEL_DIS | TIMING_WR_EN;
writel(exp_timing_cs0, p->csr_base + EXP_TIMING_CS0);
return 0;
release:
iounmap(p->csr_base);
return err;
}
static const struct pci_device_id vr_nor_pci_ids[] = {
{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x500D)},
{0,}
};
static void vr_nor_pci_remove(struct pci_dev *dev)
{
struct vr_nor_mtd *p = pci_get_drvdata(dev);
vr_nor_destroy_partitions(p);
vr_nor_destroy_mtd_setup(p);
vr_nor_destroy_maps(p);
kfree(p);
pci_release_regions(dev);
pci_disable_device(dev);
}
static int vr_nor_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
struct vr_nor_mtd *p = NULL;
unsigned int exp_timing_cs0;
int err;
err = pci_enable_device(dev);
if (err)
goto out;
err = pci_request_regions(dev, DRV_NAME);
if (err)
goto disable_dev;
p = kzalloc(sizeof(*p), GFP_KERNEL);
err = -ENOMEM;
if (!p)
goto release;
p->dev = dev;
err = vr_nor_init_maps(p);
if (err)
goto release;
err = vr_nor_mtd_setup(p);
if (err)
goto destroy_maps;
err = vr_nor_init_partitions(p);
if (err)
goto destroy_mtd_setup;
pci_set_drvdata(dev, p);
return 0;
destroy_mtd_setup:
map_destroy(p->info);
destroy_maps:
/* write-protect the flash bank */
exp_timing_cs0 = readl(p->csr_base + EXP_TIMING_CS0);
exp_timing_cs0 &= ~TIMING_WR_EN;
writel(exp_timing_cs0, p->csr_base + EXP_TIMING_CS0);
/* unmap the flash window */
iounmap(p->map.virt);
/* unmap the csr window */
iounmap(p->csr_base);
release:
kfree(p);
pci_release_regions(dev);
disable_dev:
pci_disable_device(dev);
out:
return err;
}
static struct pci_driver vr_nor_pci_driver = {
.name = DRV_NAME,
.probe = vr_nor_pci_probe,
.remove = vr_nor_pci_remove,
.id_table = vr_nor_pci_ids,
};
module_pci_driver(vr_nor_pci_driver);
MODULE_AUTHOR("Andy Lowe");
MODULE_DESCRIPTION("MTD map driver for NOR flash on Intel Vermilion Range");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, vr_nor_pci_ids);