> -Original Message-
> From: Stefan Agner [mailto:ste...@agner.ch]
> Sent: Monday, September 26, 2016 7:19 PM
> To: w...@the-dreams.de
> Cc: Leo Li ; linux-...@vger.kernel.org; u.kleine-
> koe...@pengutronix.de; linux-kernel@vger.kernel.org; Stefan Agner
>
> Subject: [PATCH] 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
Acked-by: Li Yang
> ---
> This is an actual issue on NXP Vybrid devices on which the GPIO
> driver gets loaded rather later.
>
> --
> Stefan
>
> drivers/i2c/busses/i2c-imx.c | 11 +++
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> 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 @@ 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;
> }
> --
> 2.10.0
