Re: [PATCH v7 05/12] mux: support simplified bindings for single-user gpio mux

From: Peter Rosin
Date: Thu Jan 05 2017 - 11:22:04 EST


On 2017-01-04 13:16, Peter Rosin wrote:
> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
> ---
> drivers/mux/mux-core.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++--
> drivers/mux/mux-gpio.c | 56 ++--------------------------------
> include/linux/mux.h | 7 +++++
> 3 files changed, 89 insertions(+), 55 deletions(-)
>
> diff --git a/drivers/mux/mux-core.c b/drivers/mux/mux-core.c
> index 21da15a264ad..d887ae1c0e55 100644
> --- a/drivers/mux/mux-core.c
> +++ b/drivers/mux/mux-core.c
> @@ -15,6 +15,7 @@
> #include <linux/device.h>
> #include <linux/err.h>
> #include <linux/idr.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/module.h>
> #include <linux/mux.h>
> #include <linux/of.h>
> @@ -288,6 +289,63 @@ static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np)
> return dev ? to_mux_chip(dev) : NULL;
> }
>
> +#ifdef CONFIG_MUX_GPIO
> +
> +static int mux_gpio_set(struct mux_control *mux, int state)
> +{
> + struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip);
> + int i;
> +
> + for (i = 0; i < mux_gpio->gpios->ndescs; i++)
> + mux_gpio->val[i] = (state >> i) & 1;
> +
> + gpiod_set_array_value_cansleep(mux_gpio->gpios->ndescs,
> + mux_gpio->gpios->desc,
> + mux_gpio->val);
> +
> + return 0;
> +}
> +
> +static const struct mux_control_ops mux_gpio_ops = {
> + .set = mux_gpio_set,
> +};
> +
> +struct mux_chip *mux_gpio_alloc(struct device *dev)
> +{
> + struct mux_chip *mux_chip;
> + struct mux_gpio *mux_gpio;
> + int pins;
> + int ret;
> +
> + pins = gpiod_count(dev, "mux");
> + if (pins < 0)
> + return ERR_PTR(pins);
> +
> + mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio) +
> + pins * sizeof(*mux_gpio->val));
> + if (!mux_chip)
> + return ERR_PTR(-ENOMEM);
> +
> + mux_gpio = mux_chip_priv(mux_chip);
> + mux_gpio->val = (int *)(mux_gpio + 1);
> + mux_chip->ops = &mux_gpio_ops;
> +
> + mux_gpio->gpios = devm_gpiod_get_array(dev, "mux", GPIOD_OUT_LOW);
> + if (IS_ERR(mux_gpio->gpios)) {
> + ret = PTR_ERR(mux_gpio->gpios);
> + if (ret != -EPROBE_DEFER)
> + dev_err(dev, "failed to get gpios\n");
> + 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);
> +
> +#endif /* CONFIG_MUX_GPIO */
> +
> struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
> {
> struct device_node *np = dev->of_node;
> @@ -307,9 +365,28 @@ 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 && gpiod_count(dev, "mux") > 0) {
> + mux_chip = mux_gpio_alloc(dev);
> + if (!IS_ERR(mux_chip)) {
> + ret = devm_mux_chip_register(dev, mux_chip);
> + if (ret < 0) {
> + dev_err(dev, "failed to register mux-chip\n");
> + 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 76b52bc63470..8a7bfbc0c4bb 100644
> --- a/drivers/mux/mux-gpio.c
> +++ b/drivers/mux/mux-gpio.c
> @@ -11,37 +11,12 @@
> */
>
> #include <linux/err.h>
> -#include <linux/gpio/consumer.h>
> #include <linux/module.h>
> #include <linux/mux.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> #include <linux/property.h>

Instead of moving the mux-gpio guts from mux-gpio.c to mux-core.c, I
will instead make CONFIG_MUX_GPIO a bool option (no module possible)
and call it from the mux-core. That will be cleaner and less of a
break of abstractions in my opinion.

Cheers,
Peter

> -struct mux_gpio {
> - struct gpio_descs *gpios;
> - int *val;
> -};
> -
> -static int mux_gpio_set(struct mux_control *mux, int state)
> -{
> - struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip);
> - int i;
> -
> - for (i = 0; i < mux_gpio->gpios->ndescs; i++)
> - mux_gpio->val[i] = (state >> i) & 1;
> -
> - gpiod_set_array_value_cansleep(mux_gpio->gpios->ndescs,
> - mux_gpio->gpios->desc,
> - mux_gpio->val);
> -
> - return 0;
> -}
> -
> -static const struct mux_control_ops mux_gpio_ops = {
> - .set = mux_gpio_set,
> -};
> -
> static const struct of_device_id mux_gpio_dt_ids[] = {
> { .compatible = "mux-gpio", },
> { /* sentinel */ }
> @@ -51,38 +26,13 @@ MODULE_DEVICE_TABLE(of, mux_gpio_dt_ids);
> static int mux_gpio_probe(struct platform_device *pdev)
> {
> 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;
>
> - if (!np)
> - return -ENODEV;
> -
> - pins = gpiod_count(dev, "mux");
> - if (pins < 0)
> - return pins;
> -
> - mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio) +
> - pins * sizeof(*mux_gpio->val));
> - if (!mux_chip)
> - return -ENOMEM;
> -
> - mux_gpio = mux_chip_priv(mux_chip);
> - mux_gpio->val = (int *)(mux_gpio + 1);
> - mux_chip->ops = &mux_gpio_ops;
> -
> - mux_gpio->gpios = devm_gpiod_get_array(dev, "mux", GPIOD_OUT_LOW);
> - if (IS_ERR(mux_gpio->gpios)) {
> - ret = PTR_ERR(mux_gpio->gpios);
> - if (ret != -EPROBE_DEFER)
> - dev_err(dev, "failed to get gpios\n");
> - return ret;
> - }
> - WARN_ON(pins != mux_gpio->gpios->ndescs);
> - mux_chip->mux->states = 1 << pins;
> + 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) {
> diff --git a/include/linux/mux.h b/include/linux/mux.h
> index 3b9439927f11..3bfee23cfb8c 100644
> --- a/include/linux/mux.h
> +++ b/include/linux/mux.h
> @@ -241,4 +241,11 @@ struct mux_control *devm_mux_control_get(struct device *dev,
> */
> void devm_mux_control_put(struct device *dev, struct mux_control *mux);
>
> +struct mux_gpio {
> + struct gpio_descs *gpios;
> + int *val;
> +};
> +
> +struct mux_chip *mux_gpio_alloc(struct device *dev);
> +
> #endif /* _LINUX_MUX_H */
>