w1: ds2760: add support for EEPROM read and write

In order to modify the DS2762's status registers and to add support for
sleep mode, there is need for functions to write the internal EEPROM.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Acked-by: Matt Reimer <mreimer@vpop.net>
Acked-by: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

drivers/w1/slaves/w1_ds2760.c

@@ -68,6 +68,34 @@ int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count)
 	return w1_ds2760_io(dev, buf, addr, count, 1);
 }
 
+static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
+{
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+	if (!dev)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->mutex);
+
+	if (w1_reset_select_slave(sl) == 0) {
+		w1_write_8(sl->master, cmd);
+		w1_write_8(sl->master, addr);
+	}
+
+	mutex_unlock(&sl->master->mutex);
+	return 0;
+}
+
+int w1_ds2760_store_eeprom(struct device *dev, int addr)
+{
+	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
+}
+
+int w1_ds2760_recall_eeprom(struct device *dev, int addr)
+{
+	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
+}
+
 static ssize_t w1_ds2760_read_bin(struct kobject *kobj,
 				  struct bin_attribute *bin_attr,
 				  char *buf, loff_t off, size_t count)
@@ -200,6 +228,8 @@ static void __exit w1_ds2760_exit(void)
 
 EXPORT_SYMBOL(w1_ds2760_read);
 EXPORT_SYMBOL(w1_ds2760_write);
+EXPORT_SYMBOL(w1_ds2760_store_eeprom);
+EXPORT_SYMBOL(w1_ds2760_recall_eeprom);
 
 module_init(w1_ds2760_init);
 module_exit(w1_ds2760_exit);

drivers/w1/slaves/w1_ds2760.h

@@ -46,5 +46,7 @@ extern int w1_ds2760_read(struct device *dev, char *buf, int addr,
 			  size_t count);
 extern int w1_ds2760_write(struct device *dev, char *buf, int addr,
 			   size_t count);
+extern int w1_ds2760_store_eeprom(struct device *dev, int addr);
+extern int w1_ds2760_recall_eeprom(struct device *dev, int addr);
 
 #endif /* !__w1_ds2760_h__ */