[PATCH 4/4] eeprom: at24: reserve EEPROM names which have an alias

[Sascha Hauer]

An EEPROM which doesn't have an alias will be registered as "eeprom0".
When another EEPROM is probed which has "eeprom0" as alias it will fail
to probe due to -EEXIST. Use of_alias_get_highest_id() to reserve
namespace for EEPROMs with aliases.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/eeprom/at24.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/eeprom/at24.c b/drivers/eeprom/at24.c
index 667d111b349d6941c757da3c6eb46ad7f2bb422e..5dc19800970093fa8c95f36d58d47d8c1db6dcdc 100644
--- a/drivers/eeprom/at24.c
+++ b/drivers/eeprom/at24.c
@@ -369,7 +369,7 @@ static int at24_probe(struct device *dev)
 	struct at24_platform_data chip;
 	bool writable;
 	struct at24_data *at24;
-	int err;
+	int devid, err;
 	unsigned i, num_addresses;
 	const char *devname;
 	const char *alias;
@@ -423,10 +423,14 @@ static int at24_probe(struct device *dev)
 	at24->num_addresses = num_addresses;
 
 	alias = of_alias_get(dev->of_node);
-	if (alias)
+	if (alias) {
 		devname = alias;
-	else
+		devid = NVMEM_DEVID_NONE;
+	} else {
 		devname = "eeprom";
+		devid = get_free_deviceid_from(devname,
+					       of_alias_get_highest_id(devname) + 1);
+	}
 
 	writable = !(chip.flags & AT24_FLAG_READONLY);
 
@@ -481,7 +485,7 @@ static int at24_probe(struct device *dev)
 	at24->nvmem_config.stride = 1;
 	at24->nvmem_config.word_size = 1;
 	at24->nvmem_config.size = chip.byte_len;
-	at24->nvmem_config.id = alias ? NVMEM_DEVID_NONE : NVMEM_DEVID_AUTO;
+	at24->nvmem_config.id = devid;
 
 	at24->nvmem = nvmem_register(&at24->nvmem_config);
 	err = PTR_ERR_OR_ZERO(at24->nvmem);

-- 
2.47.3