The patch titled
memory_accessor: implement the new memory_accessor interfaces for SPI EEPROMs
has been added to the -mm tree. Its filename is
memory_accessor-implement-the-new-memory_accessor-interfaces-for-spi-eeproms.patch
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------------------------------------------------------
Subject: memory_accessor: implement the new memory_accessor interfaces for SPI EEPROMs
From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
- Define new setup() hook to export the accessor
- Implement accessor methods
Moves some error checking out of the sysfs interface code into the layer
below it, which is now shared by both sysfs and memory access code.
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
Cc: Jean Delvare <khali@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/misc/eeprom/at25.c | 58 ++++++++++++++++++++++++++---------
include/linux/spi/eeprom.h | 6 +++
2 files changed, 50 insertions(+), 14 deletions(-)
diff -puN drivers/misc/eeprom/at25.c~memory_accessor-implement-the-new-memory_accessor-interfaces-for-spi-eeproms drivers/misc/eeprom/at25.c
--- a/drivers/misc/eeprom/at25.c~memory_accessor-implement-the-new-memory_accessor-interfaces-for-spi-eeproms
+++ a/drivers/misc/eeprom/at25.c
@@ -30,6 +30,7 @@
struct at25_data {
struct spi_device *spi;
+ struct memory_accessor mem;
struct mutex lock;
struct spi_eeprom chip;
struct bin_attribute bin;
@@ -75,6 +76,13 @@ at25_ee_read(
struct spi_transfer t[2];
struct spi_message m;
+ if (unlikely(offset >= at25->bin.size))
+ return 0;
+ if ((offset + count) > at25->bin.size)
+ count = at25->bin.size - offset;
+ if (unlikely(!count))
+ return count;
+
cp = command;
*cp++ = AT25_READ;
@@ -127,13 +135,6 @@ at25_bin_read(struct kobject *kobj, stru
dev = container_of(kobj, struct device, kobj);
at25 = dev_get_drvdata(dev);
- if (unlikely(off >= at25->bin.size))
- return 0;
- if ((off + count) > at25->bin.size)
- count = at25->bin.size - off;
- if (unlikely(!count))
- return count;
-
return at25_ee_read(at25, buf, off, count);
}
@@ -146,6 +147,13 @@ at25_ee_write(struct at25_data *at25, ch
unsigned buf_size;
u8 *bounce;
+ if (unlikely(off >= at25->bin.size))
+ return -EFBIG;
+ if ((off + count) > at25->bin.size)
+ count = at25->bin.size - off;
+ if (unlikely(!count))
+ return count;
+
/* Temp buffer starts with command and address */
buf_size = at25->chip.page_size;
if (buf_size > io_limit)
@@ -253,18 +261,31 @@ at25_bin_write(struct kobject *kobj, str
dev = container_of(kobj, struct device, kobj);
at25 = dev_get_drvdata(dev);
- if (unlikely(off >= at25->bin.size))
- return -EFBIG;
- if ((off + count) > at25->bin.size)
- count = at25->bin.size - off;
- if (unlikely(!count))
- return count;
-
return at25_ee_write(at25, buf, off, count);
}
/*-------------------------------------------------------------------------*/
+/* Let in-kernel code access the eeprom data. */
+
+static ssize_t at25_mem_read(struct memory_accessor *mem, char *buf,
+ off_t offset, size_t count)
+{
+ struct at25_data *at25 = container_of(mem, struct at25_data, mem);
+
+ return at25_ee_read(at25, buf, offset, count);
+}
+
+static ssize_t at25_mem_write(struct memory_accessor *mem, char *buf,
+ off_t offset, size_t count)
+{
+ struct at25_data *at25 = container_of(mem, struct at25_data, mem);
+
+ return at25_ee_write(at25, buf, offset, count);
+}
+
+/*-------------------------------------------------------------------------*/
+
static int at25_probe(struct spi_device *spi)
{
struct at25_data *at25 = NULL;
@@ -317,6 +338,10 @@ static int at25_probe(struct spi_device
at25->addrlen = addrlen;
/* Export the EEPROM bytes through sysfs, since that's convenient.
+ * And maybe to other kernel code; it might hold a board's Ethernet
+ * address, or board-specific calibration data generated on the
+ * manufacturing floor.
+ *
* Default to root-only access to the data; EEPROMs often hold data
* that's sensitive for read and/or write, like ethernet addresses,
* security codes, board-specific manufacturing calibrations, etc.
@@ -324,17 +349,22 @@ static int at25_probe(struct spi_device
at25->bin.attr.name = "eeprom";
at25->bin.attr.mode = S_IRUSR;
at25->bin.read = at25_bin_read;
+ at25->mem.read = at25_mem_read;
at25->bin.size = at25->chip.byte_len;
if (!(chip->flags & EE_READONLY)) {
at25->bin.write = at25_bin_write;
at25->bin.attr.mode |= S_IWUSR;
+ at25->mem.write = at25_mem_write;
}
err = sysfs_create_bin_file(&spi->dev.kobj, &at25->bin);
if (err)
goto fail;
+ if (chip->setup)
+ chip->setup(&at25->mem, chip->context);
+
dev_info(&spi->dev, "%Zd %s %s eeprom%s, pagesize %u\n",
(at25->bin.size < 1024)
? at25->bin.size
diff -puN include/linux/spi/eeprom.h~memory_accessor-implement-the-new-memory_accessor-interfaces-for-spi-eeproms include/linux/spi/eeprom.h
--- a/include/linux/spi/eeprom.h~memory_accessor-implement-the-new-memory_accessor-interfaces-for-spi-eeproms
+++ a/include/linux/spi/eeprom.h
@@ -1,6 +1,8 @@
#ifndef __LINUX_SPI_EEPROM_H
#define __LINUX_SPI_EEPROM_H
+#include <linux/memory.h>
+
/*
* Put one of these structures in platform_data for SPI EEPROMS handled
* by the "at25" driver. On SPI, most EEPROMS understand the same core
@@ -17,6 +19,10 @@ struct spi_eeprom {
#define EE_ADDR2 0x0002 /* 16 bit addrs */
#define EE_ADDR3 0x0004 /* 24 bit addrs */
#define EE_READONLY 0x0008 /* disallow writes */
+
+ /* for exporting this chip's data to other kernel code */
+ void (*setup)(struct memory_accessor *mem, void *context);
+ void *context;
};
#endif /* __LINUX_SPI_EEPROM_H */
_
Patches currently in -mm which might be from dbrownell@xxxxxxxxxxxxxxxxxxxxx are
origin.patch
linux-next.patch
memory_accessor-new-interface-for-reading-writing-persistent-memory.patch
memory_accessor-implement-the-new-memory_accessor-interface-for-i2c-eeprom.patch
memory_accessor-implement-the-new-memory_accessor-interfaces-for-spi-eeproms.patch
blackfin-spi-driver-fix-erroneous-spi-clock-divisor-calculation.patch
blackfin-spi-driver-remove-useless-asm-cplbinith.patch
blackfin-spi-driver-use-len_in_bytes-when-we-care-about-the-number-of-bytes-transferred.patch
blackfin-spi-driver-pass-dma-overflow-error-to-the-higher-level.patch
blackfin-spi-driver-unify-duplicated-code-in-dma-read-write-paths.patch
blackfin-spi-driver-drop-bogus-cast-and-touchup-dma-label.patch
blackfin-spi-driver-get-dma-working-for-spi-flashes.patch
blackfin-spi-driver-fix-bug-spi-controller-driver-does-not-assert-deassert-cs-correctly.patch
blackfin-spi-driver-fix-bug-correct-usage-of-struct-spi_transfercs_change.patch
spi-limit-reaches-1-tested-0.patch
rtc-ds1307-true-smbus-compatibility.patch
gpio-gpio_requestfree-now-required-feature-removal.patch
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