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

drivers/i2c/busses/i2c-imx.c

@@ -1009,10 +1009,13 @@ static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,
 	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;
 	}