From patchwork Fri Sep 21 15:32:13 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxime Ripard X-Patchwork-Id: 1492061 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 872CE3FE65 for ; Fri, 21 Sep 2012 15:35:18 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TF5EG-0001iN-VO; Fri, 21 Sep 2012 15:33:21 +0000 Received: from mail.free-electrons.com ([88.190.12.23]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TF5Df-0001Z3-QX for linux-arm-kernel@lists.infradead.org; Fri, 21 Sep 2012 15:32:46 +0000 Received: by mail.free-electrons.com (Postfix, from userid 106) id 3B1D2E3; Fri, 21 Sep 2012 17:31:32 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.free-electrons.com X-Spam-Level: X-Spam-Status: No, score=-3.2 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 shortcircuit=no autolearn=ham version=3.3.1 Received: from localhost (gar31-2-82-226-185-134.fbx.proxad.net [82.226.185.134]) by mail.free-electrons.com (Postfix) with ESMTPSA id F2CD7143; Fri, 21 Sep 2012 17:31:11 +0200 (CEST) From: Maxime Ripard To: peter.korsgaard@barco.com, shawn.guo@linaro.org Subject: [PATCH 2/3] i2c: mux: Add dt support to i2c-mux-gpio driver Date: Fri, 21 Sep 2012 17:32:13 +0200 Message-Id: <1348241535-27754-3-git-send-email-maxime.ripard@free-electrons.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1348241535-27754-1-git-send-email-maxime.ripard@free-electrons.com> References: <1348241535-27754-1-git-send-email-maxime.ripard@free-electrons.com> X-Spam-Note: CRM114 invocation failed X-Spam-Score: -2.4 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.4 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -0.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: brian@crystalfontz.com, linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Allow the i2c-mux-gpio to be used by a device tree enabled device. The bindings are inspired by the one found in the i2c-mux-pinctrl driver. Signed-off-by: Maxime Ripard --- .../devicetree/bindings/i2c/i2c-mux-gpio.txt | 86 +++++++++++ drivers/i2c/muxes/i2c-mux-gpio.c | 158 +++++++++++++++----- 2 files changed, 208 insertions(+), 36 deletions(-) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt new file mode 100644 index 0000000..f2bd120 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-gpio.txt @@ -0,0 +1,86 @@ +GPIO-based I2C Bus Mux + +This binding describes an I2C bus multiplexer that uses GPIOs to +route the I2C signals. + + +-----+ +-----+ + | dev | | dev | + +------------------------+ +-----+ +-----+ + | SoC | | | + | /----|------+--------+ + | +---+ +------+ | child bus A, on GPIO value set to 0 + | |I2C|---| Mux | | + | +---+ +--+---+ | child bus B, on GPIO value set to 1 + | | \----|------+--------+--------+ + | +------+ | | | | | + | | GPIO |---+ | +-----+ +-----+ +-----+ + | +------+ | | dev | | dev | | dev | + +------------------------+ +-----+ +-----+ +-----+ + +Required properties: +- compatible: i2c-mux-gpio +- i2c-parent: The phandle of the I2C bus that this multiplexer's master-side + port is connected to. + +Also required are: + +- muxer-gpios: list of gpios to use to control the muxer + +* Standard I2C mux properties. See mux.txt in this directory. + +* I2C child bus nodes. See mux.txt in this directory. + +For each i2c child nodes, an I2C child bus will be created. They will +be numbered based on the reg property of each nodes. + +Whenever an access is made to a device on a child bus, the value set +in the revelant node's reg property will be outputed using the list of +GPIOs, the first in the list holding the most-significant value. + +If an idle state is defined, using the idle-state (optional) property, +whenever an access is not being made to a device on a child bus, the +idle value will be programmed into the GPIOs. + +If an idle state is not defined, the most recently used value will be +left programmed into hardware whenever no access is being made of a +device on a child bus. + +Example: + i2cmux { + compatible = "i2c-mux-gpio"; + #address-cells = <1>; + #size-cells = <0>; + muxer-gpios = <&gpio1 22 0 &gpio1 23 0>; + i2c-parent = <&i2c1>; + + i2c@0 { + reg = <0>; + #address-cells = <1>; + #size-cells = <0>; + }; + + i2c@1 { + reg = <1>; + #address-cells = <1>; + #size-cells = <0>; + }; + + i2c@2 { + reg = <2>; + #address-cells = <1>; + #size-cells = <0>; + }; + + i2c@3 { + reg = <3>; + #address-cells = <1>; + #size-cells = <0>; + + pca9555: pca9555@20 { + compatible = "nxp,pca9555"; + gpio-controller; + #gpio-cells = <2>; + reg = <0x20>; + }; + }; + }; diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c index fbc400b..108caaa 100644 --- a/drivers/i2c/muxes/i2c-mux-gpio.c +++ b/drivers/i2c/muxes/i2c-mux-gpio.c @@ -16,26 +16,28 @@ #include #include #include +#include +#include struct gpiomux { struct i2c_adapter *parent; struct i2c_adapter **adap; /* child busses */ - struct i2c_mux_gpio_platform_data data; + struct i2c_mux_gpio_platform_data *data; }; static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val) { int i; - for (i = 0; i < mux->data.n_gpios; i++) - gpio_set_value(mux->data.gpios[i], val & (1 << i)); + for (i = 0; i < mux->data->n_gpios; i++) + gpio_set_value(mux->data->gpios[i], val & (1 << i)); } static int i2c_mux_gpio_select(struct i2c_adapter *adap, void *data, u32 chan) { struct gpiomux *mux = data; - i2c_mux_gpio_set(mux, mux->data.values[chan]); + i2c_mux_gpio_set(mux, mux->data->values[chan]); return 0; } @@ -44,67 +46,146 @@ static int i2c_mux_gpio_deselect(struct i2c_adapter *adap, void *data, u32 chan) { struct gpiomux *mux = data; - i2c_mux_gpio_set(mux, mux->data.idle); + i2c_mux_gpio_set(mux, mux->data->idle); return 0; } +#ifdef CONFIG_OF +static int __devinit i2c_mux_gpio_probe_dt(struct gpiomux *mux, + struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct device_node *adapter_np, *child; + struct i2c_adapter *adapter; + unsigned *values, *gpios; + int i = 0; + + if (!np) + return 0; + + mux->data = devm_kzalloc(&pdev->dev, sizeof(*mux->data), + GFP_KERNEL); + if (!mux->data) { + dev_err(&pdev->dev, "Cannot allocate platform_data"); + return -ENOMEM; + } + + adapter_np = of_parse_phandle(np, "i2c-parent", 0); + if (!adapter_np) { + dev_err(&pdev->dev, "Cannot parse i2c-parent\n"); + return -ENODEV; + } + adapter = of_find_i2c_adapter_by_node(adapter_np); + if (!adapter) { + dev_err(&pdev->dev, "Cannot find parent bus\n"); + return -ENODEV; + } + mux->data->parent = i2c_adapter_id(adapter); + put_device(&adapter->dev); + + mux->data->n_values = of_get_child_count(np); + + values = devm_kzalloc(&pdev->dev, sizeof(*mux->data->values), GFP_KERNEL); + if (!values) { + dev_err(&pdev->dev, "Cannot allocate values array"); + return -ENOMEM; + } + + for_each_child_of_node(np, child) { + of_property_read_u32(child, "reg", values + i); + i++; + } + mux->data->values = values; + + if (of_property_read_u32(np, "idle-state", &mux->data->idle)) + mux->data->idle = I2C_MUX_GPIO_NO_IDLE; + + mux->data->n_gpios = of_gpio_named_count(np, "muxer-gpios"); + if (mux->data->n_gpios < 0) { + dev_err(&pdev->dev, "Missing muxer-gpios property in the DT.\n"); + return -EINVAL; + } + + gpios = devm_kzalloc(&pdev->dev, mux->data->n_gpios, GFP_KERNEL); + if (!gpios) { + dev_err(&pdev->dev, "Cannot allocate gpios array"); + return -ENOMEM; + } + + for (i = 0; i < mux->data->n_gpios; i++) + gpios[i] = of_get_named_gpio(np, "muxer-gpios", i); + + mux->data->gpios = gpios; + + return 0; +} +#else +static int __devinit i2c_mux_gpio_probe_dt(struct gpiomux *mux, + struct platform_device *pdev) +{ + return 0; +} +#endif + static int __devinit i2c_mux_gpio_probe(struct platform_device *pdev) { struct gpiomux *mux; - struct i2c_mux_gpio_platform_data *pdata; struct i2c_adapter *parent; int (*deselect) (struct i2c_adapter *, void *, u32); unsigned initial_state; int i, ret; - pdata = pdev->dev.platform_data; - if (!pdata) { - dev_err(&pdev->dev, "Missing platform data\n"); - return -ENODEV; + mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL); + if (!mux) { + dev_err(&pdev->dev, "Cannot allocate gpiomux structure"); + return -ENOMEM; } - parent = i2c_get_adapter(pdata->parent); + platform_set_drvdata(pdev, mux); + + mux->data = pdev->dev.platform_data; + if (!mux->data) { + ret = i2c_mux_gpio_probe_dt(mux, pdev); + if (ret < 0) + return ret; + } + + parent = i2c_get_adapter(mux->data->parent); if (!parent) { dev_err(&pdev->dev, "Parent adapter (%d) not found\n", - pdata->parent); + mux->data->parent); return -ENODEV; } - mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL); - if (!mux) { - ret = -ENOMEM; - goto alloc_failed; - } - mux->parent = parent; - mux->data = *pdata; mux->adap = devm_kzalloc(&pdev->dev, - sizeof(struct i2c_adapter *) * pdata->n_values, + sizeof(struct i2c_adapter *) * mux->data->n_values, GFP_KERNEL); if (!mux->adap) { + dev_err(&pdev->dev, "Cannot allocate i2c_adapter structure"); ret = -ENOMEM; goto alloc_failed; } - if (pdata->idle != I2C_MUX_GPIO_NO_IDLE) { - initial_state = pdata->idle; + if (mux->data->idle != I2C_MUX_GPIO_NO_IDLE) { + initial_state = mux->data->idle; deselect = i2c_mux_gpio_deselect; } else { - initial_state = pdata->values[0]; + initial_state = mux->data->values[0]; deselect = NULL; } - for (i = 0; i < pdata->n_gpios; i++) { - ret = gpio_request(pdata->gpios[i], "i2c-mux-gpio"); + for (i = 0; i < mux->data->n_gpios; i++) { + ret = gpio_request(mux->data->gpios[i], "i2c-mux-gpio"); if (ret) goto err_request_gpio; - gpio_direction_output(pdata->gpios[i], + gpio_direction_output(mux->data->gpios[i], initial_state & (1 << i)); } - for (i = 0; i < pdata->n_values; i++) { - u32 nr = pdata->base_nr ? (pdata->base_nr + i) : 0; + for (i = 0; i < mux->data->n_values; i++) { + u32 nr = mux->data->base_nr ? (mux->data->base_nr + i) : 0; mux->adap[i] = i2c_add_mux_adapter(parent, &pdev->dev, mux, nr, i, i2c_mux_gpio_select, deselect); @@ -116,19 +197,17 @@ static int __devinit i2c_mux_gpio_probe(struct platform_device *pdev) } dev_info(&pdev->dev, "%d port mux on %s adapter\n", - pdata->n_values, parent->name); - - platform_set_drvdata(pdev, mux); + mux->data->n_values, parent->name); return 0; add_adapter_failed: for (; i > 0; i--) i2c_del_mux_adapter(mux->adap[i - 1]); - i = pdata->n_gpios; + i = mux->data->n_gpios; err_request_gpio: for (; i > 0; i--) - gpio_free(pdata->gpios[i - 1]); + gpio_free(mux->data->gpios[i - 1]); alloc_failed: i2c_put_adapter(parent); @@ -140,11 +219,11 @@ static int __devexit i2c_mux_gpio_remove(struct platform_device *pdev) struct gpiomux *mux = platform_get_drvdata(pdev); int i; - for (i = 0; i < mux->data.n_values; i++) + for (i = 0; i < mux->data->n_values; i++) i2c_del_mux_adapter(mux->adap[i]); - for (i = 0; i < mux->data.n_gpios; i++) - gpio_free(mux->data.gpios[i]); + for (i = 0; i < mux->data->n_gpios; i++) + gpio_free(mux->data->gpios[i]); platform_set_drvdata(pdev, NULL); i2c_put_adapter(mux->parent); @@ -152,12 +231,19 @@ static int __devexit i2c_mux_gpio_remove(struct platform_device *pdev) return 0; } +static const struct of_device_id i2c_mux_gpio_of_match[] __devinitconst = { + { .compatible = "i2c-mux-gpio", }, + {}, +}; +MODULE_DEVICE_TABLE(of, i2c_mux_gpio_of_match); + static struct platform_driver i2c_mux_gpio_driver = { .probe = i2c_mux_gpio_probe, .remove = __devexit_p(i2c_mux_gpio_remove), .driver = { .owner = THIS_MODULE, .name = "i2c-mux-gpio", + .of_match_table = of_match_ptr(i2c_mux_gpio_of_match), }, };