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[80.98.18.187]) by smtp.gmail.com with ESMTPSA id e134sm17336478wma.31.2017.10.05.04.03.45 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 05 Oct 2017 04:03:45 -0700 (PDT) From: Linus Walleij To: Wolfram Sang , linux-i2c@vger.kernel.org Cc: Linus Walleij Subject: [PATCH 7/7 v3] i2c: gpio: Add support for named gpios in DT Date: Thu, 5 Oct 2017 13:03:10 +0200 Message-Id: <20171005110310.5900-8-linus.walleij@linaro.org> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20171005110310.5900-1-linus.walleij@linaro.org> References: <20171005110310.5900-1-linus.walleij@linaro.org> Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org This adds support for using the "sda" and "scl" GPIOs in device tree instead of anonymously using index 0 and 1 of the "gpios" property. We add a helper function to retrieve the GPIO descriptors and some explicit error handling since the probe may have to be deferred. At least this happened to me when moving to using named "sda" and "scl" lines (all of a sudden this started to probe before the GPIO driver) so we need to gracefully defer probe when we ge -ENOENT in the error pointer. Suggested-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Signed-off-by: Linus Walleij --- ChangeLog v2->v3: - Switched using %d to print error code rather than %ld This is pretty much a rewrite of Geerts patch on top of my own changes to support descriptors. --- drivers/i2c/busses/i2c-gpio.c | 59 +++++++++++++++++++++++++++++++------------ 1 file changed, 43 insertions(+), 16 deletions(-) diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c index a702e493275c..d80ea6ce91bb 100644 --- a/drivers/i2c/busses/i2c-gpio.c +++ b/drivers/i2c/busses/i2c-gpio.c @@ -82,6 +82,42 @@ static void of_i2c_gpio_get_props(struct device_node *np, of_property_read_bool(np, "i2c-gpio,scl-output-only"); } +static struct gpio_desc *i2c_gpio_get_desc(struct device *dev, + const char *con_id, + unsigned int index, + enum gpiod_flags gflags) +{ + struct gpio_desc *retdesc; + int ret; + + retdesc = devm_gpiod_get(dev, con_id, gflags); + if (!IS_ERR(retdesc)) { + dev_dbg(dev, "got GPIO from name %s\n", con_id); + return retdesc; + } + + retdesc = devm_gpiod_get_index(dev, NULL, index, gflags); + if (!IS_ERR(retdesc)) { + dev_dbg(dev, "got GPIO from index %u\n", index); + return retdesc; + } + + ret = PTR_ERR(retdesc); + + /* FIXME: hack in the old code, is this really necessary? */ + if (ret == -EINVAL) + retdesc = ERR_PTR(-EPROBE_DEFER); + + /* This happens if the GPIO driver is not yet probed, let's defer */ + if (ret == -ENOENT) + retdesc = ERR_PTR(-EPROBE_DEFER); + + if (ret != -EPROBE_DEFER) + dev_err(dev, "error trying to get descriptor: %d\n", ret); + + return retdesc; +} + static int i2c_gpio_probe(struct platform_device *pdev) { struct i2c_gpio_private_data *priv; @@ -124,14 +160,10 @@ static int i2c_gpio_probe(struct platform_device *pdev) gflags = GPIOD_OUT_HIGH; else gflags = GPIOD_OUT_HIGH_OPEN_DRAIN; - priv->sda = devm_gpiod_get_index(dev, NULL, 0, gflags); - if (IS_ERR(priv->sda)) { - ret = PTR_ERR(priv->sda); - /* FIXME: hack in the old code, is this really necessary? */ - if (ret == -EINVAL) - ret = -EPROBE_DEFER; - return ret; - } + priv->sda = i2c_gpio_get_desc(dev, "sda", 0, gflags); + if (IS_ERR(priv->sda)) + return PTR_ERR(priv->sda); + /* * If the SCL line is marked from platform data or device tree as * "open drain" it means something outside of our control is making @@ -143,14 +175,9 @@ static int i2c_gpio_probe(struct platform_device *pdev) gflags = GPIOD_OUT_LOW; else gflags = GPIOD_OUT_LOW_OPEN_DRAIN; - priv->scl = devm_gpiod_get_index(dev, NULL, 1, gflags); - if (IS_ERR(priv->scl)) { - ret = PTR_ERR(priv->scl); - /* FIXME: hack in the old code, is this really necessary? */ - if (ret == -EINVAL) - ret = -EPROBE_DEFER; - return ret; - } + priv->scl = i2c_gpio_get_desc(dev, "scl", 1, gflags); + if (IS_ERR(priv->scl)) + return PTR_ERR(priv->scl); bit_data->setsda = i2c_gpio_setsda_val; bit_data->setscl = i2c_gpio_setscl_val;