diff options
| -rw-r--r-- | drivers/misc/eeprom/at25.c | 58 | ||||
| -rw-r--r-- | include/linux/spi/eeprom.h | 6 |
2 files changed, 50 insertions, 14 deletions
diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c index 290dbe9..6bc0dac 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 diff --git a/include/linux/spi/eeprom.h b/include/linux/spi/eeprom.h index 1085212..306e7b1 100644 --- a/include/linux/spi/eeprom.h +++ b/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 */ |
