The patch titled
SPI: EEPROM learns about 8 and 24 bit addressing
has been removed from the -mm tree. Its filename was
spi-eeprom-learns-about-8-and-24-bit-addressing.patch
This patch was dropped because it was folded into spi-eeprom-driver.patch
------------------------------------------------------
Subject: SPI: EEPROM learns about 8 and 24 bit addressing
From: "Tuppa, Walter" <walter.tuppa@xxxxxxxxxxx>
Since I have EEPROMs on SPI with different address sizing, I made some
changes to your at25.c to support them. Works perfectly. (Also includes a
small bugfix for the "what size address" test.)
Signed-off-by: Walter Tuppa <walter.tuppa@xxxxxxxxxxx>
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/spi/at25.c | 78 +++++++++++++++++++++++++++++--------------
1 file changed, 54 insertions(+), 24 deletions(-)
diff -puN drivers/spi/at25.c~spi-eeprom-learns-about-8-and-24-bit-addressing drivers/spi/at25.c
--- a/drivers/spi/at25.c~spi-eeprom-learns-about-8-and-24-bit-addressing
+++ a/drivers/spi/at25.c
@@ -26,6 +26,7 @@ struct at25_data {
struct mutex lock;
struct spi_eeprom chip;
struct bin_attribute bin;
+ unsigned addrlen;
};
#define AT25_WREN 0x06 /* latch the write enable */
@@ -42,6 +43,8 @@ struct at25_data {
#define AT25_SR_WPEN 0x80 /* writeprotect enable */
+#define EE_MAXADDRLEN 3 /* 24 bit addresses, up to 2 MBytes */
+
/* Specs often allow 5 msec for a page write, sometimes 20 msec;
* it's important to recover from write timeouts.
*/
@@ -59,21 +62,31 @@ at25_ee_read(
size_t count
)
{
- u8 command[3];
+ u8 command[EE_MAXADDRLEN + 1];
+ u8 *cp;
ssize_t status;
struct spi_transfer t[2];
struct spi_message m;
- /* 16-bit address is written MSB first */
- command[0] = AT25_READ;
- command[1] = (u8) (offset >> 8);
- command[2] = (u8) (offset >> 0);
+ cp = command;
+ *cp++ = AT25_READ;
+
+ /* 8/16/24-bit address is written MSB first */
+ switch (at25->addrlen) {
+ default: /* case 3 */
+ *cp++ = offset >> 16;
+ case 2:
+ *cp++ = offset >> 8;
+ case 1:
+ case 0: /* can't happen: for better codegen */
+ *cp++ = offset >> 0;
+ }
spi_message_init(&m);
memset(t, 0, sizeof t);
t[0].tx_buf = command;
- t[0].len = 3;
+ t[0].len = at25->addrlen + 1;
spi_message_add_tail(&t[0], &m);
t[1].rx_buf = buf;
@@ -129,7 +142,7 @@ at25_ee_write(struct at25_data *at25, ch
buf_size = at25->chip.page_size;
if (buf_size > io_limit)
buf_size = io_limit;
- bounce = kmalloc(buf_size + 3, GFP_KERNEL);
+ bounce = kmalloc(buf_size + at25->addrlen + 1, GFP_KERNEL);
if (!bounce)
return -ENOMEM;
@@ -142,28 +155,37 @@ at25_ee_write(struct at25_data *at25, ch
unsigned long timeout, retries;
unsigned segment;
unsigned offset = (unsigned) off;
+ u8 *cp = bounce + 1;
- bounce[3] = AT25_WREN;
- status = spi_write(at25->spi, bounce + 3, 1);
+ *cp = AT25_WREN;
+ status = spi_write(at25->spi, cp, 1);
if (status < 0) {
dev_dbg(&at25->spi->dev, "WREN --> %d\n",
(int) status);
break;
}
- /* 16-bit address is written MSB first */
- bounce[1] = (u8)(offset >> 8);
- bounce[2] = (u8)(offset >> 0);
+ /* 8/16/24-bit address is written MSB first */
+ switch (at25->addrlen) {
+ default: /* case 3 */
+ *cp++ = offset >> 16;
+ case 2:
+ *cp++ = offset >> 8;
+ case 1:
+ case 0: /* can't happen: for better codegen */
+ *cp++ = offset >> 0;
+ }
/* Write as much of a page as we can */
segment = buf_size - (offset % buf_size);
if (segment > count)
segment = count;
- memcpy(&bounce[3], buf, segment);
- status = spi_write(at25->spi, bounce, segment + 3);
+ memcpy(cp, buf, segment);
+ status = spi_write(at25->spi, bounce,
+ segment + at25->addrlen + 1);
dev_dbg(&at25->spi->dev,
- "write %u bytes at %u --> %d\n",
- segment, offset, (int) status);
+ "write %u bytes at %u --> %d\n",
+ segment, offset, (int) status);
if (status < 0)
break;
@@ -240,6 +262,7 @@ static int at25_probe(struct spi_device
const struct spi_eeprom *chip;
int err;
int sr;
+ int addrlen;
/* Chip description */
chip = spi->dev.platform_data;
@@ -249,12 +272,14 @@ static int at25_probe(struct spi_device
goto fail;
}
- /* For now we only support 16 bit addressing, for
- * chips from 512 bytes to 64 Kbytes (4-512 Kbits).
- *
- * REVISIT some chips use 8 or 24 bit addressing
- */
- if (!chip->flags & EE_ADDR2) {
+ /* For now we only support 8/16/24 bit addressing */
+ if (chip->flags & EE_ADDR1)
+ addrlen = 1;
+ else if (chip->flags & EE_ADDR2)
+ addrlen = 2;
+ else if (chip->flags & EE_ADDR3)
+ addrlen = 3;
+ else {
dev_dbg(&spi->dev, "unsupported address type\n");
err = -EINVAL;
goto fail;
@@ -280,6 +305,7 @@ static int at25_probe(struct spi_device
at25->chip = *chip;
at25->spi = spi_dev_get(spi);
dev_set_drvdata(&spi->dev, at25);
+ at25->addrlen = addrlen;
/* Export the EEPROM bytes through sysfs, since that's convenient.
* Default to root-only access to the data; EEPROMs often hold data
@@ -301,8 +327,12 @@ static int at25_probe(struct spi_device
if (err)
goto fail;
- dev_info(&spi->dev, "%Zd KByte %s eeprom%s, pagesize %u\n",
- at25->bin.size / 1024, at25->chip.name,
+ dev_info(&spi->dev, "%Zd %s %s eeprom%s, pagesize %u\n",
+ (at25->bin.size < 1024)
+ ? at25->bin.size
+ : (at25->bin.size / 1024),
+ (at25->bin.size < 1024) ? "Byte" : "KByte",
+ at25->chip.name,
(chip->flags & EE_READONLY) ? " (readonly)" : "",
at25->chip.page_size);
return 0;
_
Patches currently in -mm which might be from walter.tuppa@xxxxxxxxxxx are
spi-eeprom-driver.patch
spi-eeprom-learns-about-8-and-24-bit-addressing.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
