i2c: Set default I2C bus number

This patch allows using i2c commands (e.g. "i2c probe", "i2c md", etc)
without the need to first select the bus number with e.g. "i2c dev 0".

This is the "i2c" command behavior similar to the one from pre DM, where
by default bus 0 was immediately accessible.

Signed-off-by: Lukasz Majewski <lukma@denx.de>

1 files changed, 10 insertions, 0 deletions

diff --git a/cmd/i2c.c b/cmd/i2c.c
index 473153fbd4..3dd7c6ba4d 100644
--- a/cmd/i2c.c
+++ b/cmd/i2c.c
@@ -151,6 +151,16 @@ static int cmd_i2c_set_bus_num(unsigned int busnum)
 
 static int i2c_get_cur_bus(struct udevice **busp)
 {
+#ifdef CONFIG_I2C_SET_DEFAULT_BUS_NUM
+	if (!i2c_cur_bus) {
+		if (cmd_i2c_set_bus_num(CONFIG_I2C_DEFAULT_BUS_NUMBER)) {
+			printf("Default I2C bus %d not found\n",
+			       CONFIG_I2C_DEFAULT_BUS_NUMBER);
+			return -ENODEV;
+		}
+	}
+#endif
+
 	if (!i2c_cur_bus) {
 		puts("No I2C bus selected\n");
 		return -ENODEV;