diff options
Diffstat (limited to 'target/linux/generic-2.6')
| -rw-r--r-- | target/linux/generic-2.6/patches-2.6.27/450-i2c_at24_add_kernel_interface_read_write.patch | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/target/linux/generic-2.6/patches-2.6.27/450-i2c_at24_add_kernel_interface_read_write.patch b/target/linux/generic-2.6/patches-2.6.27/450-i2c_at24_add_kernel_interface_read_write.patch new file mode 100644 index 0000000000..36a3e69125 --- /dev/null +++ b/target/linux/generic-2.6/patches-2.6.27/450-i2c_at24_add_kernel_interface_read_write.patch @@ -0,0 +1,134 @@ +Subject: [PATCH 2/3] I2C: at24: add kernel interface for reading/writing EEPROM +Date: Monday 25 August 2008 +From: Kevin Hilman <khilman@deeprootsystems.com> +To: davinci-linux-open-source@linux.davincidsp.com + +This patch adds an interface by which other kernel code can read/write +detected EEPROM. + +The platform code registers a 'setup' callback with the +at24_platform_data. When the at24 driver detects an EEPROM, it fills +out the read and write functions of at24_iface and calls the setup +callback. The platform code can then use the read/write functions in +the at24_iface struct for reading and writing the EEPROM. + +Original idea, review and updates by David Brownell <david-b@pacbell.net> + +Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> +--- + drivers/i2c/chips/at24.c | 42 +++++++++++++++++++++++++++++++++++------- + include/linux/i2c/at24.h | 10 ++++++++++ + 2 files changed, 45 insertions(+), 7 deletions(-) + +--- a/drivers/i2c/chips/at24.c ++++ b/drivers/i2c/chips/at24.c +@@ -53,6 +53,7 @@ + + struct at24_data { + struct at24_platform_data chip; ++ struct at24_iface iface; + bool use_smbus; + + /* +@@ -264,13 +265,6 @@ static ssize_t at24_bin_read(struct kobj + + + /* +- * REVISIT: export at24_bin{read,write}() to let other kernel code use +- * eeprom data. For example, it might hold a board's Ethernet address, or +- * board-specific calibration data generated on the manufacturing floor. +- */ +- +- +-/* + * Note that if the hardware write-protect pin is pulled high, the whole + * chip is normally write protected. But there are plenty of product + * variants here, including OTP fuses and partial chip protect. +@@ -386,6 +380,30 @@ static ssize_t at24_bin_write(struct kob + + /*-------------------------------------------------------------------------*/ + ++/* ++ * This lets other kernel code access the eeprom data. For example, it ++ * might hold a board's Ethernet address, or board-specific calibration ++ * data generated on the manufacturing floor. ++ */ ++ ++static ssize_t at24_iface_read(struct at24_iface *iface, char *buf, ++ off_t offset, size_t count) ++{ ++ struct at24_data *at24 = container_of(iface, struct at24_data, iface); ++ ++ return at24_eeprom_read(at24, buf, offset, count); ++} ++ ++static ssize_t at24_iface_write(struct at24_iface *iface, char *buf, ++ off_t offset, size_t count) ++{ ++ struct at24_data *at24 = container_of(iface, struct at24_data, iface); ++ ++ return at24_eeprom_write(at24, buf, offset, count); ++} ++ ++/*-------------------------------------------------------------------------*/ ++ + static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) + { + struct at24_platform_data chip; +@@ -413,6 +431,9 @@ static int at24_probe(struct i2c_client + * is recommended anyhow. + */ + chip.page_size = 1; ++ ++ chip.setup = NULL; ++ chip.context = NULL; + } + + if (!is_power_of_2(chip.byte_len)) +@@ -449,6 +470,9 @@ static int at24_probe(struct i2c_client + goto err_out; + } + ++ at24->iface.read = at24_iface_read; ++ at24->iface.write = at24_iface_write; ++ + mutex_init(&at24->lock); + at24->use_smbus = use_smbus; + at24->chip = chip; +@@ -521,6 +545,10 @@ static int at24_probe(struct i2c_client + at24->write_max, + use_smbus ? ", use_smbus" : ""); + ++ /* export data to kernel code */ ++ if (chip.setup) ++ chip.setup(&at24->iface, chip.context); ++ + return 0; + + err_clients: +--- a/include/linux/i2c/at24.h ++++ b/include/linux/i2c/at24.h +@@ -15,6 +15,13 @@ + * is bigger than what the chip actually supports! + */ + ++struct at24_iface { ++ ssize_t (*read)(struct at24_iface *, char *buf, off_t offset, ++ size_t count); ++ ssize_t (*write)(struct at24_iface *, char *buf, off_t offset, ++ size_t count); ++}; ++ + struct at24_platform_data { + u32 byte_len; /* size (sum of all addr) */ + u16 page_size; /* for writes */ +@@ -23,6 +30,9 @@ struct at24_platform_data { + #define AT24_FLAG_READONLY 0x40 /* sysfs-entry will be read-only */ + #define AT24_FLAG_IRUGO 0x20 /* sysfs-entry will be world-readable */ + #define AT24_FLAG_TAKE8ADDR 0x10 /* take always 8 addresses (24c00) */ ++ ++ int (*setup)(struct at24_iface *, void *context); ++ void *context; + }; + + #endif /* _LINUX_AT24_H */ |