diff options
author | Wolfram Sang <w.sang@pengutronix.de> | 2010-11-17 13:00:48 +0100 |
---|---|---|
committer | Grant Likely <grant.likely@secretlab.ca> | 2010-12-24 02:13:36 -0700 |
commit | 9ed030d728f3bd03b6e869357da02725afda19a7 (patch) | |
tree | 2dfe452c10e5562a817197d686e7bed61d946fe4 | |
parent | 194588604765ac803f98fb9d19a36f6b835f4620 (diff) |
misc/at24: parse device tree data
Information about the pagesize and read-only-status may also come from
the devicetree. Parse this data, too, and act accordingly. While we are
here, change the initialization printout a bit. write_max is useful to
know to detect performance bottlenecks, the rest is superfluous.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
-rw-r--r-- | Documentation/powerpc/dts-bindings/eeprom.txt | 28 | ||||
-rw-r--r-- | drivers/misc/eeprom/at24.c | 33 |
2 files changed, 55 insertions, 6 deletions
diff --git a/Documentation/powerpc/dts-bindings/eeprom.txt b/Documentation/powerpc/dts-bindings/eeprom.txt new file mode 100644 index 000000000000..4342c10de1bf --- /dev/null +++ b/Documentation/powerpc/dts-bindings/eeprom.txt @@ -0,0 +1,28 @@ +EEPROMs (I2C) + +Required properties: + + - compatible : should be "<manufacturer>,<type>" + If there is no specific driver for <manufacturer>, a generic + driver based on <type> is selected. Possible types are: + 24c00, 24c01, 24c02, 24c04, 24c08, 24c16, 24c32, 24c64, + 24c128, 24c256, 24c512, 24c1024, spd + + - reg : the I2C address of the EEPROM + +Optional properties: + + - pagesize : the length of the pagesize for writing. Please consult the + manual of your device, that value varies a lot. A wrong value + may result in data loss! If not specified, a safety value of + '1' is used which will be very slow. + + - read-only: this parameterless property disables writes to the eeprom + +Example: + +eeprom@52 { + compatible = "atmel,24c32"; + reg = <0x52>; + pagesize = <32>; +}; diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 559b0b3c16c3..3a53efc28821 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -20,6 +20,7 @@ #include <linux/log2.h> #include <linux/bitops.h> #include <linux/jiffies.h> +#include <linux/of.h> #include <linux/i2c.h> #include <linux/i2c/at24.h> @@ -457,6 +458,27 @@ static ssize_t at24_macc_write(struct memory_accessor *macc, const char *buf, /*-------------------------------------------------------------------------*/ +#ifdef CONFIG_OF +static void at24_get_ofdata(struct i2c_client *client, + struct at24_platform_data *chip) +{ + const __be32 *val; + struct device_node *node = client->dev.of_node; + + if (node) { + if (of_get_property(node, "read-only", NULL)) + chip->flags |= AT24_FLAG_READONLY; + val = of_get_property(node, "pagesize", NULL); + if (val) + chip->page_size = be32_to_cpup(val); + } +} +#else +static void at24_get_ofdata(struct i2c_client *client, + struct at24_platform_data *chip) +{ } +#endif /* CONFIG_OF */ + static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct at24_platform_data chip; @@ -485,6 +507,9 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) */ chip.page_size = 1; + /* update chipdata if OF is present */ + at24_get_ofdata(client, &chip); + chip.setup = NULL; chip.context = NULL; } @@ -597,19 +622,15 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) i2c_set_clientdata(client, at24); - dev_info(&client->dev, "%zu byte %s EEPROM %s\n", + dev_info(&client->dev, "%zu byte %s EEPROM, %s, %u bytes/write\n", at24->bin.size, client->name, - writable ? "(writable)" : "(read-only)"); + writable ? "writable" : "read-only", at24->write_max); if (use_smbus == I2C_SMBUS_WORD_DATA || use_smbus == I2C_SMBUS_BYTE_DATA) { dev_notice(&client->dev, "Falling back to %s reads, " "performance will suffer\n", use_smbus == I2C_SMBUS_WORD_DATA ? "word" : "byte"); } - dev_dbg(&client->dev, - "page_size %d, num_addresses %d, write_max %d, use_smbus %d\n", - chip.page_size, num_addresses, - at24->write_max, use_smbus); /* export data to kernel code */ if (chip.setup) |