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author | 2009-04-02 16:56:58 -0700 | |
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committer | 2009-04-02 19:04:50 -0700 | |
commit | 14dd1ff0f9e75dd4ae2f1ff8e48becb76d14f4ab (patch) | |
tree | a9e208f0c35c8e24ed0edb8a1bc5ca9a4dc9b585 /drivers/misc | |
parent | memory_accessor: implement the new memory_accessor interface for I2C EEPROM (diff) | |
download | linux-14dd1ff0f9e75dd4ae2f1ff8e48becb76d14f4ab.tar.gz linux-14dd1ff0f9e75dd4ae2f1ff8e48becb76d14f4ab.tar.bz2 linux-14dd1ff0f9e75dd4ae2f1ff8e48becb76d14f4ab.zip |
memory_accessor: implement the new memory_accessor interfaces for SPI EEPROMs
- 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@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/misc')
-rw-r--r-- | drivers/misc/eeprom/at25.c | 58 |
1 files changed, 44 insertions, 14 deletions
diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c index 290dbe99647a..6bc0dac5c1e8 100644 --- a/drivers/misc/eeprom/at25.c +++ b/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, struct bin_attribute *bin_attr, 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, char *buf, loff_t off, size_t count) 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, struct bin_attribute *bin_attr, 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 *spi) 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 *spi) 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 |