#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/mtd/mtd.h>
#include <linux/platform_device.h>
#include <linux/bcma/bcma.h>
#include "bcm47xxsflash.h"
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Serial flash driver for BCMA bus");
static const char * const probes[] = { "bcm47xxpart", NULL };
/**************************************************
* Various helpers
**************************************************/
static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode)
{
int i;
b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode);
for (i = 0; i < 1000; i++) {
if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) &
BCMA_CC_FLASHCTL_BUSY))
return;
cpu_relax();
}
pr_err("Control command failed (timeout)!\n");
}
static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout)
{
unsigned long deadline = jiffies + timeout;
do {
switch (b47s->type) {
case BCM47XXSFLASH_TYPE_ST:
bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR);
if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
SR_ST_WIP))
return 0;
break;
case BCM47XXSFLASH_TYPE_ATMEL:
bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS);
if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
SR_AT_READY)
return 0;
break;
}
cpu_relax();
udelay(1);
} while (!time_after_eq(jiffies, deadline));
pr_err("Timeout waiting for flash to be ready!\n");
return -EBUSY;
}
/**************************************************
* MTD ops
**************************************************/
static int bcm47xxsflash_erase(struct mtd_info *mtd, struct erase_info *erase)
{
struct bcm47xxsflash *b47s = mtd->priv;
int err;
switch (b47s->type) {
case BCM47XXSFLASH_TYPE_ST:
bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);
b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr);
/* Newer flashes have "sub-sectors" which can be erased
* independently with a new command: ST_SSE. The ST_SE command
* erases 64KB just as before.
*/
if (b47s->blocksize < (64 * 1024))
bcm47xxsflash_cmd(b47s, OPCODE_ST_SSE);
else
bcm47xxsflash_cmd(b47s, OPCODE_ST_SE);
break;
case BCM47XXSFLASH_TYPE_ATMEL:
b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr << 1);
bcm47xxsflash_cmd(b47s, OPCODE_AT_PAGE_ERASE);
break;
}
err = bcm47xxsflash_poll(b47s, HZ);
if (err)
erase->state = MTD_ERASE_FAILED;
else
erase->state = MTD_ERASE_DONE;
if (erase->callback)
erase->callback(erase);
return err;
}
static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
struct bcm47xxsflash *b47s = mtd->priv;
/* Check address range */
if ((from + len) > mtd->size)
return -EINVAL;
memcpy_fromio(buf, b47s->window + from, len);
*retlen = len;
return len;
}
static int bcm47xxsflash_write_st(struct mtd_info *mtd, u32 offset, size_t len,
const u_char *buf)
{
struct bcm47xxsflash *b47s = mtd->priv;
int written = 0;
/* Enable writes */
bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);
/* Write first byte */
b47s->cc_write(b47s, BCMA_CC_FLASHADDR, offset);
b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);
/* Program page */
if (b47s->bcma_cc->core->id.rev < 20) {
bcm47xxsflash_cmd(b47s, OPCODE_ST_PP);
return 1; /* 1B written */
}
/* Program page and set CSA (on newer chips we can continue writing) */
bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | OPCODE_ST_PP);
offset++;
len--;
written++;
while (len > 0) {
/* Page boundary, another function call is needed */
if ((offset & 0xFF) == 0)
break;
bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | *buf++);
offset++;
len--;
written++;
}
/* All done, drop CSA & poll */
b47s->cc_write(b47s, BCMA_CC_FLASHCTL, 0);
udelay(1);
if (bcm47xxsflash_poll(b47s, HZ / 10))
pr_err("Flash rejected dropping CSA\n");
return written;
}
static int bcm47xxsflash_write_at(struct mtd_info *mtd, u32 offset, size_t len,
const u_char *buf)
{
struct bcm47xxsflash *b47s = mtd->priv;
u32 mask = b47s->blocksize - 1;
u32 page = (offset & ~mask) << 1;
u32 byte = offset & mask;
int written = 0;
/* If we don't overwrite whole page, read it to the buffer first */
if (byte || (len < b47s->blocksize)) {
int err;
b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);
bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_LOAD);
/* 250 us for AT45DB321B */
err = bcm47xxsflash_poll(b47s, HZ / 1000);
if (err) {
pr_err("Timeout reading page 0x%X info buffer\n", page);
return err;
}
}
/* Change buffer content with our data */
while (len > 0) {
/* Page boundary, another function call is needed */
if (byte == b47s->blocksize)
break;
b47s->cc_write(b47s, BCMA_CC_FLASHADDR, byte++);
b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);
bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_WRITE);
len--;
written++;
}
/* Program page with the buffer content */
b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);
bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_PROGRAM);
return written;
}
static int bcm47xxsflash_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
struct bcm47xxsflash *b47s = mtd->priv;
int written;
/* Writing functions can return without writing all passed data, for
* example when the hardware is too old or when we git page boundary.
*/
while (len > 0) {
switch (b47s->type) {
case BCM47XXSFLASH_TYPE_ST:
written = bcm47xxsflash_write_st(mtd, to, len, buf);
break;
case BCM47XXSFLASH_TYPE_ATMEL:
written = bcm47xxsflash_write_at(mtd, to, len, buf);
break;
default:
BUG_ON(1);
}
if (written < 0) {
pr_err("Error writing at offset 0x%llX\n", to);
return written;
}
to += (loff_t)written;
len -= written;
*retlen += written;
buf += written;
}
return 0;
}
static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s,
struct device *dev)
{
struct mtd_info *mtd = &b47s->mtd;
mtd->priv = b47s;
mtd->dev.parent = dev;
mtd->name = "bcm47xxsflash";
mtd->type = MTD_NORFLASH;
mtd->flags = MTD_CAP_NORFLASH;
mtd->size = b47s->size;
mtd->erasesize = b47s->blocksize;
mtd->writesize = 1;
mtd->writebufsize = 1;
mtd->_erase = bcm47xxsflash_erase;
mtd->_read = bcm47xxsflash_read;
mtd->_write = bcm47xxsflash_write;
}
/**************************************************
* BCMA
**************************************************/
static int bcm47xxsflash_bcma_cc_read(struct bcm47xxsflash *b47s, u16 offset)
{
return bcma_cc_read32(b47s->bcma_cc, offset);
}
static void bcm47xxsflash_bcma_cc_write(struct bcm47xxsflash *b47s, u16 offset,
u32 value)
{
bcma_cc_write32(b47s->bcma_cc, offset, value);
}
static int bcm47xxsflash_bcma_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct bcma_sflash *sflash = dev_get_platdata(dev);
struct bcm47xxsflash *b47s;
struct resource *res;
int err;
b47s = devm_kzalloc(dev, sizeof(*b47s), GFP_KERNEL);
if (!b47s)
return -ENOMEM;
sflash->priv = b47s;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(dev, "invalid resource\n");
return -EINVAL;
}
if (!devm_request_mem_region(dev, res->start, resource_size(res),
res->name)) {
dev_err(dev, "can't request region for resource %pR\n", res);
return -EBUSY;
}
b47s->window = ioremap_cache(res->start, resource_size(res));
if (!b47s->window) {
dev_err(dev, "ioremap failed for resource %pR\n", res);
return -ENOMEM;
}
b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash);
b47s->cc_read = bcm47xxsflash_bcma_cc_read;
b47s->cc_write = bcm47xxsflash_bcma_cc_write;
switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) {
case BCMA_CC_FLASHT_STSER:
b47s->type = BCM47XXSFLASH_TYPE_ST;
break;
case BCMA_CC_FLASHT_ATSER:
b47s->type = BCM47XXSFLASH_TYPE_ATMEL;
break;
}
b47s->blocksize = sflash->blocksize;
b47s->numblocks = sflash->numblocks;
b47s->size = sflash->size;
bcm47xxsflash_fill_mtd(b47s, &pdev->dev);
err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0);
if (err) {
pr_err("Failed to register MTD device: %d\n", err);
iounmap(b47s->window);
return err;
}
if (bcm47xxsflash_poll(b47s, HZ / 10))
pr_warn("Serial flash busy\n");
return 0;
}
static int bcm47xxsflash_bcma_remove(struct platform_device *pdev)
{
struct bcma_sflash *sflash = dev_get_platdata(&pdev->dev);
struct bcm47xxsflash *b47s = sflash->priv;
mtd_device_unregister(&b47s->mtd);
iounmap(b47s->window);
return 0;
}
static struct platform_driver bcma_sflash_driver = {
.probe = bcm47xxsflash_bcma_probe,
.remove = bcm47xxsflash_bcma_remove,
.driver = {
.name = "bcma_sflash",
},
};
/**************************************************
* Init
**************************************************/
module_platform_driver(bcma_sflash_driver);
