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 at pengutronix.de>
---
Grant: As mentioned at ELCE10, I could pretty much respin this old approach I
tried roughly a year ago (just with archdata then). If the approach and docs
are good, I am fine with the patches entering via one of your trees.
Documentation/powerpc/dts-bindings/eeprom.txt | 28 ++++++++++++++++++++++
drivers/misc/eeprom/at24.c | 33 ++++++++++++++++++++-----
2 files changed, 53 insertions(+), 6 deletions(-)
create mode 100644 Documentation/powerpc/dts-bindings/eeprom.txt
diff --git a/Documentation/powerpc/dts-bindings/eeprom.txt b/Documentation/powerpc/dts-bindings/eeprom.txt
new file mode 100644
index 0000000..4342c10
--- /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 at 52 {
+ compatible = "atmel,24c32";
+ reg = <0x52>;
+ pagesize = <32>;
+};
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 559b0b3..aaf16cb 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 u32 *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 = *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)
--
1.7.2.3