The at24 driver is now capable of reading the serial number from at24cs
EEPROM chips. Export the serial number through sysfs.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
drivers/misc/eeprom/at24.c | 44 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 40 insertions(+), 4 deletions(-)
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 4d4a793..0eded22 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -64,6 +64,7 @@ struct at24_data {
*/
struct mutex lock;
struct bin_attribute bin;
+ struct bin_attribute *bin_serial;
u8 *writebuf;
unsigned write_max;
@@ -102,6 +103,7 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
#define AT24_BITMASK(x) (BIT(x) - 1)
+#define AT24CS_SERIAL_SIZE 16
#define AT24CS_SERIAL_ADDR(addr) (addr + 0x08)
/* create non-zero magic value for given eeprom parameters */
@@ -156,10 +158,8 @@ static struct i2c_client *at24_translate_offset(struct at24_data *at24,
return at24->client[i];
}
-static int __attribute__((unused)) at24cs_eeprom_serial_read(
- struct at24_data *at24,
- char *buf, unsigned offset,
- size_t count)
+static int at24cs_eeprom_serial_read(struct at24_data *at24, char *buf,
+ unsigned offset, size_t count)
{
unsigned long timeout, read_time;
struct i2c_client *client;
@@ -221,6 +221,16 @@ static int __attribute__((unused)) at24cs_eeprom_serial_read(
return -ETIMEDOUT;
}
+static ssize_t at24cs_bin_serial_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *attr,
+ char *buf, loff_t off, size_t count)
+{
+ struct at24_data *at24;
+
+ at24 = dev_get_drvdata(container_of(kobj, struct device, kobj));
+ return at24cs_eeprom_serial_read(at24, buf, off, count);
+}
+
static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf,
unsigned offset, size_t count)
{
@@ -637,6 +647,30 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
at24->bin.read = at24_bin_read;
at24->bin.size = chip.byte_len;
+ if (at24->chip.flags & AT24_FLAG_SERIAL) {
+ /*
+ * For EEPROMs containing the serial number export an
+ * additional file allowing allowing convenvient access
+ * to it from user-space.
+ */
+ at24->bin_serial = devm_kzalloc(&client->dev,
+ sizeof(struct bin_attribute),
+ GFP_KERNEL);
+ if (!at24->bin_serial)
+ return -ENOMEM;
+
+ sysfs_bin_attr_init(at24->bin_serial);
+ at24->bin_serial->attr.name = "serial";
+ at24->bin_serial->attr.mode = S_IRUSR;
+ at24->bin_serial->read = at24cs_bin_serial_read;
+ at24->bin_serial->size = AT24CS_SERIAL_SIZE;
+
+ err = sysfs_create_bin_file(&client->dev.kobj,
+ at24->bin_serial);
+ if (err)
+ goto err_clients;
+ }
+
at24->macc.read = at24_macc_read;
writable = !(chip.flags & AT24_FLAG_READONLY);
@@ -736,6 +770,8 @@ static int at24_remove(struct i2c_client *client)
at24 = i2c_get_clientdata(client);
sysfs_remove_bin_file(&client->dev.kobj, &at24->bin);
+ if (at24->bin_serial)
+ sysfs_remove_bin_file(&client->dev.kobj, at24->bin_serial);
for (i = 1; i < at24->num_addresses; i++)
i2c_unregister_device(at24->client[i]);
--
2.1.4
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