u-boot/drivers/mtd/spi/ramtron.c

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/*
* (C) Copyright 2010
* Reinhard Meyer, EMK Elektronik, reinhard.meyer@emk-elektronik.de
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* Note: RAMTRON SPI FRAMs are ferroelectric, nonvolatile RAMs
* with an interface identical to SPI flash devices.
* However since they behave like RAM there are no delays or
* busy polls required. They can sustain read or write at the
* allowed SPI bus speed, which can be 40 MHz for some devices.
*
* Unfortunately some RAMTRON devices do not have a means of
* identifying them. They will leave the SO line undriven when
* the READ-ID command is issued. It is therefore mandatory
* that the MISO line has a proper pull-up, so that READ-ID
* will return a row of 0xff. This 0xff pseudo-id will cause
* probes by all vendor specific functions that are designed
* to handle it. If the MISO line is not pulled up, READ-ID
* could return any random noise, even mimicking another
* device.
*
* We use CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
* to define which device will be assumed after a simple status
* register verify. This method is prone to false positive
* detection and should therefore be the last to be tried.
* Enter it in the last position in the table in spi_flash.c!
*
* The define CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC both activates
* compilation of the special handler and defines the device
* to assume.
*/
#include <common.h>
#include <malloc.h>
#include <spi_flash.h>
#include "spi_flash_internal.h"
/* RAMTRON commands common to all devices */
#define CMD_RAMTRON_WREN 0x06 /* Write Enable */
#define CMD_RAMTRON_WRDI 0x04 /* Write Disable */
#define CMD_RAMTRON_RDSR 0x05 /* Read Status Register */
#define CMD_RAMTRON_WRSR 0x01 /* Write Status Register */
#define CMD_RAMTRON_READ 0x03 /* Read Data Bytes */
#define CMD_RAMTRON_WRITE 0x02 /* Write Data Bytes */
/* not all have those: */
#define CMD_RAMTRON_FSTRD 0x0b /* Fast Read (for compatibility - not used here) */
#define CMD_RAMTRON_SLEEP 0xb9 /* Enter Sleep Mode */
#define CMD_RAMTRON_RDID 0x9f /* Read ID */
#define CMD_RAMTRON_SNR 0xc3 /* Read Serial Number */
/*
* Properties of supported FRAMs
* Note: speed is currently not used because we have no method to deliver that
* value to the upper layers
*/
struct ramtron_spi_fram_params {
u32 size; /* size in bytes */
u8 addr_len; /* number of address bytes */
u8 merge_cmd; /* some address bits are in the command byte */
u8 id1; /* device ID 1 (family, density) */
u8 id2; /* device ID 2 (sub, rev, rsvd) */
u32 speed; /* max. SPI clock in Hz */
const char *name; /* name for display and/or matching */
};
struct ramtron_spi_fram {
struct spi_flash flash;
const struct ramtron_spi_fram_params *params;
};
static inline struct ramtron_spi_fram *to_ramtron_spi_fram(struct spi_flash
*flash)
{
return container_of(flash, struct ramtron_spi_fram, flash);
}
/*
* table describing supported FRAM chips:
* chips without RDID command must have the values 0xff for id1 and id2
*/
static const struct ramtron_spi_fram_params ramtron_spi_fram_table[] = {
{
.size = 32*1024,
.addr_len = 2,
.merge_cmd = 0,
.id1 = 0x22,
.id2 = 0x00,
.speed = 40000000,
.name = "FM25V02",
},
{
.size = 32*1024,
.addr_len = 2,
.merge_cmd = 0,
.id1 = 0x22,
.id2 = 0x01,
.speed = 40000000,
.name = "FM25VN02",
},
{
.size = 64*1024,
.addr_len = 2,
.merge_cmd = 0,
.id1 = 0x23,
.id2 = 0x00,
.speed = 40000000,
.name = "FM25V05",
},
{
.size = 64*1024,
.addr_len = 2,
.merge_cmd = 0,
.id1 = 0x23,
.id2 = 0x01,
.speed = 40000000,
.name = "FM25VN05",
},
{
.size = 128*1024,
.addr_len = 3,
.merge_cmd = 0,
.id1 = 0x24,
.id2 = 0x00,
.speed = 40000000,
.name = "FM25V10",
},
{
.size = 128*1024,
.addr_len = 3,
.merge_cmd = 0,
.id1 = 0x24,
.id2 = 0x01,
.speed = 40000000,
.name = "FM25VN10",
},
#ifdef CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
{
.size = 256*1024,
.addr_len = 3,
.merge_cmd = 0,
.id1 = 0xff,
.id2 = 0xff,
.speed = 40000000,
.name = "FM25H20",
},
#endif
};
static int ramtron_common(struct spi_flash *flash,
u32 offset, size_t len, void *buf, u8 command)
{
struct ramtron_spi_fram *sn = to_ramtron_spi_fram(flash);
u8 cmd[4];
int cmd_len;
int ret;
if (sn->params->addr_len == 3 && sn->params->merge_cmd == 0) {
cmd[0] = command;
cmd[1] = offset >> 16;
cmd[2] = offset >> 8;
cmd[3] = offset;
cmd_len = 4;
} else if (sn->params->addr_len == 2 && sn->params->merge_cmd == 0) {
cmd[0] = command;
cmd[1] = offset >> 8;
cmd[2] = offset;
cmd_len = 3;
} else {
printf("SF: unsupported addr_len or merge_cmd\n");
return -1;
}
/* claim the bus */
ret = spi_claim_bus(flash->spi);
if (ret) {
debug("SF: Unable to claim SPI bus\n");
return ret;
}
if (command == CMD_RAMTRON_WRITE) {
/* send WREN */
ret = spi_flash_cmd_write_enable(flash);
if (ret < 0) {
debug("SF: Enabling Write failed\n");
goto releasebus;
}
}
/* do the transaction */
if (command == CMD_RAMTRON_WRITE)
ret = spi_flash_cmd_write(flash->spi, cmd, cmd_len, buf, len);
else
ret = spi_flash_cmd_read(flash->spi, cmd, cmd_len, buf, len);
if (ret < 0)
debug("SF: Transaction failed\n");
releasebus:
/* release the bus */
spi_release_bus(flash->spi);
return ret;
}
static int ramtron_read(struct spi_flash *flash,
u32 offset, size_t len, void *buf)
{
return ramtron_common(flash, offset, len, buf,
CMD_RAMTRON_READ);
}
static int ramtron_write(struct spi_flash *flash,
u32 offset, size_t len, const void *buf)
{
return ramtron_common(flash, offset, len, (void *)buf,
CMD_RAMTRON_WRITE);
}
static int ramtron_erase(struct spi_flash *flash, u32 offset, size_t len)
{
debug("SF: Erase of RAMTRON FRAMs is pointless\n");
return -1;
}
/*
* nore: we are called here with idcode pointing to the first non-0x7f byte
* already!
*/
struct spi_flash *spi_fram_probe_ramtron(struct spi_slave *spi, u8 *idcode)
{
const struct ramtron_spi_fram_params *params;
struct ramtron_spi_fram *sn;
unsigned int i;
#ifdef CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
int ret;
u8 sr;
#endif
/* NOTE: the bus has been claimed before this function is called! */
switch (idcode[0]) {
case 0xc2:
/* JEDEC conformant RAMTRON id */
for (i = 0; i < ARRAY_SIZE(ramtron_spi_fram_table); i++) {
params = &ramtron_spi_fram_table[i];
if (idcode[1] == params->id1 && idcode[2] == params->id2)
goto found;
}
break;
#ifdef CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC
case 0xff:
/*
* probably open MISO line, pulled up.
* We COULD have a non JEDEC conformant FRAM here,
* read the status register to verify
*/
ret = spi_flash_cmd(spi, CMD_RAMTRON_RDSR, &sr, 1);
if (ret)
return NULL;
/* Bits 5,4,0 are fixed 0 for all devices */
if ((sr & 0x31) != 0x00)
return NULL;
/* now find the device */
for (i = 0; i < ARRAY_SIZE(ramtron_spi_fram_table); i++) {
params = &ramtron_spi_fram_table[i];
if (!strcmp(params->name, CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC))
goto found;
}
debug("SF: Unsupported non-JEDEC RAMTRON device "
CONFIG_SPI_FRAM_RAMTRON_NON_JEDEC "\n");
break;
#endif
default:
break;
}
/* arriving here means no method has found a device we can handle */
debug("SF/ramtron: unsupported device id0=%02x id1=%02x id2=%02x\n",
idcode[0], idcode[1], idcode[2]);
return NULL;
found:
sn = malloc(sizeof(*sn));
if (!sn) {
debug("SF: Failed to allocate memory\n");
return NULL;
}
sn->params = params;
sn->flash.spi = spi;
sn->flash.name = params->name;
sn->flash.write = ramtron_write;
sn->flash.read = ramtron_read;
sn->flash.erase = ramtron_erase;
sn->flash.size = params->size;
return &sn->flash;
}