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Message-ID: <33b29f7e-3e48-b85d-ccf9-93b1d67ac634@kernel.org>
Date: Sun, 22 Jan 2017 13:30:02 +0000
From: Jonathan Cameron <jic23@...nel.org>
To: Peter Rosin <peda@...ntia.se>, linux-kernel@...r.kernel.org
Cc: Wolfram Sang <wsa@...-dreams.de>, Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Hartmut Knaack <knaack.h@....de>,
Lars-Peter Clausen <lars@...afoo.de>,
Peter Meerwald-Stadler <pmeerw@...erw.net>,
Jonathan Corbet <corbet@....net>,
Andrew Morton <akpm@...ux-foundation.org>,
linux-i2c@...r.kernel.org, devicetree@...r.kernel.org,
linux-iio@...r.kernel.org, linux-doc@...r.kernel.org
Subject: Re: [PATCH v8 12/12] mux: support simplified bindings for single-user
gpio mux
On 18/01/17 15:57, Peter Rosin wrote:
> Allow bindings for a GPIO controlled mux to be specified in the
> mux consumer node.
>
> Signed-off-by: Peter Rosin <peda@...ntia.se>
Code is good as far as I am concerned. Only question is whether this
is worth the hassle given the normal bindings don't give that high
a burden in complexity!
I don't really care either way:)
> ---
> drivers/mux/Kconfig | 5 +----
> drivers/mux/mux-core.c | 23 +++++++++++++++++++++--
> drivers/mux/mux-gpio.c | 28 +++++++++++++++++++++-------
> drivers/mux/mux-gpio.h | 13 +++++++++++++
> 4 files changed, 56 insertions(+), 13 deletions(-)
> create mode 100644 drivers/mux/mux-gpio.h
>
> diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
> index d13fcf98958e..cd161c228537 100644
> --- a/drivers/mux/Kconfig
> +++ b/drivers/mux/Kconfig
> @@ -29,7 +29,7 @@ config MUX_ADG792A
> be called mux-adg792a.
>
> config MUX_GPIO
> - tristate "GPIO-controlled Multiplexer"
> + bool "GPIO-controlled Multiplexer"
> depends on OF && GPIOLIB
> help
> GPIO-controlled Multiplexer controller.
> @@ -39,7 +39,4 @@ config MUX_GPIO
> states. The GPIO pins can be connected (by the hardware) to several
> multiplexers, which in that case will be operated in parallel.
>
> - To compile the driver as a module, choose M here: the module will
> - be called mux-gpio.
> -
> endif
> diff --git a/drivers/mux/mux-core.c b/drivers/mux/mux-core.c
> index 16a61253d164..0caafd6f5a77 100644
> --- a/drivers/mux/mux-core.c
> +++ b/drivers/mux/mux-core.c
> @@ -21,6 +21,8 @@
> #include <linux/of_platform.h>
> #include <linux/slab.h>
>
> +#include "mux-gpio.h"
> +
> static struct class mux_class = {
> .name = "mux",
> .owner = THIS_MODULE,
> @@ -314,9 +316,26 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
> ret = of_parse_phandle_with_args(np,
> "mux-controls", "#mux-control-cells",
> index, &args);
> +
> +#ifdef CONFIG_MUX_GPIO
> + if (ret == -ENOENT && !mux_name) {
> + mux_chip = mux_gpio_alloc(dev);
> + if (!IS_ERR(mux_chip)) {
> + ret = devm_mux_chip_register(dev, mux_chip);
> + if (ret < 0)
> + return ERR_PTR(ret);
> + get_device(&mux_chip->dev);
> + return mux_chip->mux;
> + }
> +
> + ret = PTR_ERR(mux_chip);
> + }
> +#endif
> +
> if (ret) {
> - dev_err(dev, "%s: failed to get mux-control %s(%i)\n",
> - np->full_name, mux_name ?: "", index);
> + if (ret != -EPROBE_DEFER)
> + dev_err(dev, "%s: failed to get mux-control %s(%i)\n",
> + np->full_name, mux_name ?: "", index);
> return ERR_PTR(ret);
> }
>
> diff --git a/drivers/mux/mux-gpio.c b/drivers/mux/mux-gpio.c
> index 48ca4d6b4fc7..2ab8735e3415 100644
> --- a/drivers/mux/mux-gpio.c
> +++ b/drivers/mux/mux-gpio.c
> @@ -18,6 +18,8 @@
> #include <linux/platform_device.h>
> #include <linux/property.h>
>
> +#include "mux-gpio.h"
> +
> struct mux_gpio {
> struct gpio_descs *gpios;
> int *val;
> @@ -48,24 +50,21 @@ static const struct of_device_id mux_gpio_dt_ids[] = {
> };
> MODULE_DEVICE_TABLE(of, mux_gpio_dt_ids);
>
> -static int mux_gpio_probe(struct platform_device *pdev)
> +struct mux_chip *mux_gpio_alloc(struct device *dev)
> {
> - struct device *dev = &pdev->dev;
> - struct device_node *np = dev->of_node;
> struct mux_chip *mux_chip;
> struct mux_gpio *mux_gpio;
> int pins;
> - u32 idle_state;
> int ret;
>
> pins = gpiod_count(dev, "mux");
> if (pins < 0)
> - return pins;
> + return ERR_PTR(pins);
>
> mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio) +
> pins * sizeof(*mux_gpio->val));
> if (!mux_chip)
> - return -ENOMEM;
> + return ERR_PTR(-ENOMEM);
>
> mux_gpio = mux_chip_priv(mux_chip);
> mux_gpio->val = (int *)(mux_gpio + 1);
> @@ -76,11 +75,26 @@ static int mux_gpio_probe(struct platform_device *pdev)
> ret = PTR_ERR(mux_gpio->gpios);
> if (ret != -EPROBE_DEFER)
> dev_err(dev, "failed to get gpios\n");
> - return ret;
> + return ERR_PTR(ret);
> }
> WARN_ON(pins != mux_gpio->gpios->ndescs);
> mux_chip->mux->states = 1 << pins;
>
> + return mux_chip;
> +}
> +EXPORT_SYMBOL_GPL(mux_gpio_alloc);
> +
> +static int mux_gpio_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct mux_chip *mux_chip;
> + u32 idle_state;
> + int ret;
> +
> + mux_chip = mux_gpio_alloc(dev);
> + if (IS_ERR(mux_chip))
> + return PTR_ERR(mux_chip);
> +
> ret = device_property_read_u32(dev, "idle-state", &idle_state);
> if (ret >= 0) {
> if (idle_state >= mux_chip->mux->states) {
> diff --git a/drivers/mux/mux-gpio.h b/drivers/mux/mux-gpio.h
> new file mode 100644
> index 000000000000..fe3e8d0173aa
> --- /dev/null
> +++ b/drivers/mux/mux-gpio.h
> @@ -0,0 +1,13 @@
> +/*
> + * GPIO-controlled multiplexer driver interface
> + *
> + * Copyright (C) 2017 Axentia Technologies AB
> + *
> + * Author: Peter Rosin <peda@...ntia.se>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +struct mux_chip *mux_gpio_alloc(struct device *dev);
>
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