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authorBartosz Golaszewski <bgolaszewski@baylibre.com>2016-06-06 10:48:54 +0200
committerWolfram Sang <wsa@the-dreams.de>2016-07-17 19:58:00 +0200
commit0b813658c11532be90cbf5f579a8ba45a8cc9dbf (patch)
treeb4212c97c25ac933d73a29474cdf8add87ba9c89 /drivers/misc
parent818d0220d857cc92cb37600758c5b47c3df3782b (diff)
eeprom: at24: add support for at24mac series
Add a new read function to the at24 driver allowing to retrieve the factory-programmed mac address embedded in chips from the at24mac family. These chips can be instantiated similarily to the at24cs family, except that there's no way of having access to both the serial number and the mac address at the same time - the user must instantiate either an at24cs or at24mac device as both special memory areas are accessible on the same slave address. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/eeprom/at24.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 3b27ff14876c..04e91e331fc5 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -139,6 +139,10 @@ static const struct i2c_device_id at24_ids[] = {
{ "24c02", AT24_DEVICE_MAGIC(2048 / 8, 0) },
{ "24cs02", AT24_DEVICE_MAGIC(16,
AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
+ { "24mac402", AT24_DEVICE_MAGIC(48 / 8,
+ AT24_FLAG_MAC | AT24_FLAG_READONLY) },
+ { "24mac602", AT24_DEVICE_MAGIC(64 / 8,
+ AT24_FLAG_MAC | AT24_FLAG_READONLY) },
/* spd is a 24c02 in memory DIMMs */
{ "spd", AT24_DEVICE_MAGIC(2048 / 8,
AT24_FLAG_READONLY | AT24_FLAG_IRUGO) },
@@ -347,6 +351,36 @@ static ssize_t at24_eeprom_read_serial(struct at24_data *at24, char *buf,
return -ETIMEDOUT;
}
+static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf,
+ unsigned int offset, size_t count)
+{
+ unsigned long timeout, read_time;
+ struct i2c_client *client;
+ struct i2c_msg msg[2];
+ u8 addrbuf[2];
+ int status;
+
+ client = at24_translate_offset(at24, &offset);
+
+ memset(msg, 0, sizeof(msg));
+ msg[0].addr = client->addr;
+ msg[0].buf = addrbuf;
+ addrbuf[0] = 0x90 + offset;
+ msg[0].len = 1;
+ msg[1].addr = client->addr;
+ msg[1].flags = I2C_M_RD;
+ msg[1].buf = buf;
+ msg[1].len = count;
+
+ loop_until_timeout(timeout, read_time) {
+ status = i2c_transfer(client->adapter, msg, 2);
+ if (status == 2)
+ return count;
+ }
+
+ return -ETIMEDOUT;
+}
+
/*
* Note that if the hardware write-protect pin is pulled high, the whole
* chip is normally write protected. But there are plenty of product
@@ -648,8 +682,16 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
at24->chip = chip;
at24->num_addresses = num_addresses;
+ if ((chip.flags & AT24_FLAG_SERIAL) && (chip.flags & AT24_FLAG_MAC)) {
+ dev_err(&client->dev,
+ "invalid device data - cannot have both AT24_FLAG_SERIAL & AT24_FLAG_MAC.");
+ return -EINVAL;
+ }
+
if (chip.flags & AT24_FLAG_SERIAL) {
at24->read_func = at24_eeprom_read_serial;
+ } else if (chip.flags & AT24_FLAG_MAC) {
+ at24->read_func = at24_eeprom_read_mac;
} else {
at24->read_func = at24->use_smbus ? at24_eeprom_read_smbus
: at24_eeprom_read_i2c;