From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Agner Subject: [PATCH] i2c: imx: defer probe if bus recovery GPIOs are not ready Date: Mon, 26 Sep 2016 17:18:58 -0700 Message-ID: <20160927001858.11601-1-stefan@agner.ch> Return-path: Received: from mail.kmu-office.ch ([178.209.48.109]:39617 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755769AbcI0ATL (ORCPT ); Mon, 26 Sep 2016 20:19:11 -0400 Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: wsa@the-dreams.de Cc: leoyang.li@nxp.com, linux-i2c@vger.kernel.org, u.kleine-koenig@pengutronix.de, linux-kernel@vger.kernel.org, Stefan Agner 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 --- 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