i2c: imx: defer probe if bus recovery GPIOs are not ready

Some SoC might load the GPIO driver after the I2C driver and
using the I2C bus recovery mechanism via GPIOs. In this case
it is crucial to defer probing if the GPIO request functions
do so, otherwise the I2C driver gets loaded without recovery
mechanisms enabled.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 592a8f2..47fc1f1 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -1009,10 +1009,13 @@
 	rinfo->sda_gpio = of_get_named_gpio(pdev->dev.of_node, "sda-gpios", 0);
 	rinfo->scl_gpio = of_get_named_gpio(pdev->dev.of_node, "scl-gpios", 0);
 
-	if (!gpio_is_valid(rinfo->sda_gpio) ||
-	    !gpio_is_valid(rinfo->scl_gpio) ||
-	    IS_ERR(i2c_imx->pinctrl_pins_default) ||
-	    IS_ERR(i2c_imx->pinctrl_pins_gpio)) {
+	if (rinfo->sda_gpio == -EPROBE_DEFER ||
+	    rinfo->scl_gpio == -EPROBE_DEFER) {
+		return -EPROBE_DEFER;
+	} else if (!gpio_is_valid(rinfo->sda_gpio) ||
+		   !gpio_is_valid(rinfo->scl_gpio) ||
+		   IS_ERR(i2c_imx->pinctrl_pins_default) ||
+		   IS_ERR(i2c_imx->pinctrl_pins_gpio)) {
 		dev_dbg(&pdev->dev, "recovery information incomplete\n");
 		return 0;
 	}