[PATCH v2 01/14] i2c: Allow overriding dev_name through board_info

From: Hans de Goede
Date: Tue Aug 15 2017 - 16:05:35 EST


For devices not instantiated through ACPI the i2c-client's device-name
gets set to <busnr>-<addr> by default, e.g. "0-0022" this means that
the device-name is dependent on the order in which the i2c-busses are
enumerated.

In some cases having a predictable constant device-name is desirable,
for example on non device-tree platforms the link between a regulator
and its consumers is specified by the platform code by setting
regulator_init_data.consumers. This array identifies the regulator's
consumers by dev_name and supply(-name). Which requires a constant
dev_name.

This commit adds a dev_name field to i2c_board_info allowing
platform code to set a contstant dev_name so that the device can
be identified by its dev_name in other platform code.

Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/i2c/i2c-core-base.c | 10 ++++++++--
include/linux/i2c.h | 2 ++
2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 1d28454..22dc8ba 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -672,10 +672,16 @@ static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
}

static void i2c_dev_set_name(struct i2c_adapter *adap,
- struct i2c_client *client)
+ struct i2c_client *client,
+ struct i2c_board_info const *info)
{
struct acpi_device *adev = ACPI_COMPANION(&client->dev);

+ if (info && info->dev_name) {
+ dev_set_name(&client->dev, "i2c-%s", info->dev_name);
+ return;
+ }
+
if (adev) {
dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
return;
@@ -772,7 +778,7 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
client->dev.of_node = info->of_node;
client->dev.fwnode = info->fwnode;

- i2c_dev_set_name(adap, client);
+ i2c_dev_set_name(adap, client, info);

if (info->properties) {
status = device_add_properties(&client->dev, info->properties);
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 701ad26..d3655cf 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -310,6 +310,7 @@ static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
* @type: chip type, to initialize i2c_client.name
* @flags: to initialize i2c_client.flags
* @addr: stored in i2c_client.addr
+ * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
* @platform_data: stored in i2c_client.dev.platform_data
* @archdata: copied into i2c_client.dev.archdata
* @of_node: pointer to OpenFirmware device node
@@ -334,6 +335,7 @@ struct i2c_board_info {
char type[I2C_NAME_SIZE];
unsigned short flags;
unsigned short addr;
+ const char *dev_name;
void *platform_data;
struct dev_archdata *archdata;
struct device_node *of_node;
--
2.9.4