[mirror_ubuntu-jammy-kernel.git] / drivers / mux / gpio.c

// SPDX-License-Identifier: GPL-2.0
/*
 * GPIO-controlled multiplexer driver
 *
 * Copyright (C) 2017 Axentia Technologies AB
 *
 * Author: Peter Rosin <peda@axentia.se>
 */

#include <linux/bitmap.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mux/driver.h>
#include <linux/platform_device.h>
#include <linux/property.h>

struct mux_gpio {
	struct gpio_descs *gpios;
};

static int mux_gpio_set(struct mux_control *mux, int state)
{
	struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip);
	DECLARE_BITMAP(values, BITS_PER_TYPE(state));
	u32 value = state;

	bitmap_from_arr32(values, &value, BITS_PER_TYPE(value));

	gpiod_set_array_value_cansleep(mux_gpio->gpios->ndescs,
				       mux_gpio->gpios->desc,
				       mux_gpio->gpios->info, values);

	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 = "gpio-mux", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mux_gpio_dt_ids);

static int mux_gpio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct mux_chip *mux_chip;
	struct mux_gpio *mux_gpio;
	int pins;
	s32 idle_state;
	int ret;

	pins = gpiod_count(dev, "mux");
	if (pins < 0)
		return pins;

	mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio));
	if (IS_ERR(mux_chip))
		return PTR_ERR(mux_chip);

	mux_gpio = mux_chip_priv(mux_chip);
	mux_chip->ops = &mux_gpio_ops;

	mux_gpio->gpios = devm_gpiod_get_array(dev, "mux", GPIOD_OUT_LOW);
	if (IS_ERR(mux_gpio->gpios))
		return dev_err_probe(dev, PTR_ERR(mux_gpio->gpios),
				     "failed to get gpios\n");
	WARN_ON(pins != mux_gpio->gpios->ndescs);
	mux_chip->mux->states = BIT(pins);

	ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state);
	if (ret >= 0 && idle_state != MUX_IDLE_AS_IS) {
		if (idle_state < 0 || idle_state >= mux_chip->mux->states) {
			dev_err(dev, "invalid idle-state %u\n", idle_state);
			return -EINVAL;
		}

		mux_chip->mux->idle_state = idle_state;
	}

	ret = devm_mux_chip_register(dev, mux_chip);
	if (ret < 0)
		return ret;

	dev_info(dev, "%u-way mux-controller registered\n",
		 mux_chip->mux->states);

	return 0;
}

static struct platform_driver mux_gpio_driver = {
	.driver = {
		.name = "gpio-mux",
		.of_match_table	= mux_gpio_dt_ids,
	},
	.probe = mux_gpio_probe,
};
module_platform_driver(mux_gpio_driver);

MODULE_DESCRIPTION("GPIO-controlled multiplexer driver");
MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
0edff03d	1	// SPDX-License-Identifier: GPL-2.0
2c089f08 PR	2	/*
	3	* GPIO-controlled multiplexer driver
	4	*
	5	* Copyright (C) 2017 Axentia Technologies AB
	6	*
	7	* Author: Peter Rosin <peda@axentia.se>
2c089f08 PR	8	*/
2c089f08 PR	9
5c777233	10	#include <linux/bitmap.h>
2c089f08 PR	11	#include <linux/err.h>
2c089f08 PR	12	#include <linux/gpio/consumer.h>
7fef54e2	13	#include <linux/mod_devicetable.h>
2c089f08 PR	14	#include <linux/module.h>
2c089f08 PR	15	#include <linux/mux/driver.h>
2c089f08 PR	16	#include <linux/platform_device.h>
	17	#include <linux/property.h>
	18
	19	struct mux_gpio {
	20	struct gpio_descs *gpios;
2c089f08 PR	21	};
	22
	23	static int mux_gpio_set(struct mux_control *mux, int state)
	24	{
	25	struct mux_gpio *mux_gpio = mux_chip_priv(mux->chip);
b9762beb	26	DECLARE_BITMAP(values, BITS_PER_TYPE(state));
5c777233	27	u32 value = state;
2c089f08	28
5c777233	29	bitmap_from_arr32(values, &value, BITS_PER_TYPE(value));
2c089f08 PR	30
2c089f08 PR	31	gpiod_set_array_value_cansleep(mux_gpio->gpios->ndescs,
77588c14 JK	32	mux_gpio->gpios->desc,
77588c14 JK	33	mux_gpio->gpios->info, values);
2c089f08 PR	34
	35	return 0;
	36	}
	37
	38	static const struct mux_control_ops mux_gpio_ops = {
	39	.set = mux_gpio_set,
	40	};
	41
	42	static const struct of_device_id mux_gpio_dt_ids[] = {
	43	{ .compatible = "gpio-mux", },
	44	{ /* sentinel */ }
	45	};
	46	MODULE_DEVICE_TABLE(of, mux_gpio_dt_ids);
	47
	48	static int mux_gpio_probe(struct platform_device *pdev)
	49	{
	50	struct device *dev = &pdev->dev;
	51	struct mux_chip *mux_chip;
	52	struct mux_gpio *mux_gpio;
	53	int pins;
	54	s32 idle_state;
	55	int ret;
	56
	57	pins = gpiod_count(dev, "mux");
	58	if (pins < 0)
	59	return pins;
	60
b9762beb	61	mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_gpio));
2c089f08 PR	62	if (IS_ERR(mux_chip))
	63	return PTR_ERR(mux_chip);
	64
	65	mux_gpio = mux_chip_priv(mux_chip);
2c089f08 PR	66	mux_chip->ops = &mux_gpio_ops;
	67
	68	mux_gpio->gpios = devm_gpiod_get_array(dev, "mux", GPIOD_OUT_LOW);
38ab8614 AS	69	if (IS_ERR(mux_gpio->gpios))
	70	return dev_err_probe(dev, PTR_ERR(mux_gpio->gpios),
	71	"failed to get gpios\n");
2c089f08	72	WARN_ON(pins != mux_gpio->gpios->ndescs);
5c777233	73	mux_chip->mux->states = BIT(pins);
2c089f08 PR	74
	75	ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state);
	76	if (ret >= 0 && idle_state != MUX_IDLE_AS_IS) {
	77	if (idle_state < 0 \|\| idle_state >= mux_chip->mux->states) {
	78	dev_err(dev, "invalid idle-state %u\n", idle_state);
	79	return -EINVAL;
	80	}
	81
	82	mux_chip->mux->idle_state = idle_state;
	83	}
	84
	85	ret = devm_mux_chip_register(dev, mux_chip);
	86	if (ret < 0)
	87	return ret;
	88
	89	dev_info(dev, "%u-way mux-controller registered\n",
	90	mux_chip->mux->states);
	91
	92	return 0;
	93	}
	94
	95	static struct platform_driver mux_gpio_driver = {
	96	.driver = {
	97	.name = "gpio-mux",
7fef54e2	98	.of_match_table = mux_gpio_dt_ids,
2c089f08 PR	99	},
	100	.probe = mux_gpio_probe,
	101	};
	102	module_platform_driver(mux_gpio_driver);
	103
	104	MODULE_DESCRIPTION("GPIO-controlled multiplexer driver");
	105	MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
	106	MODULE_LICENSE("GPL v2");