[linux-block.git] / drivers / gpio / gpio-dln2.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for the Diolan DLN-2 USB-GPIO adapter
 *
 * Copyright (c) 2014 Intel Corporation
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/irqdomain.h>
#include <linux/irq.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/mfd/dln2.h>

#define DLN2_GPIO_ID			0x01

#define DLN2_GPIO_GET_PIN_COUNT		DLN2_CMD(0x01, DLN2_GPIO_ID)
#define DLN2_GPIO_SET_DEBOUNCE		DLN2_CMD(0x04, DLN2_GPIO_ID)
#define DLN2_GPIO_GET_DEBOUNCE		DLN2_CMD(0x05, DLN2_GPIO_ID)
#define DLN2_GPIO_PORT_GET_VAL		DLN2_CMD(0x06, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_GET_VAL		DLN2_CMD(0x0B, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_SET_OUT_VAL	DLN2_CMD(0x0C, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_GET_OUT_VAL	DLN2_CMD(0x0D, DLN2_GPIO_ID)
#define DLN2_GPIO_CONDITION_MET_EV	DLN2_CMD(0x0F, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_ENABLE		DLN2_CMD(0x10, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_DISABLE		DLN2_CMD(0x11, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_SET_DIRECTION	DLN2_CMD(0x13, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_GET_DIRECTION	DLN2_CMD(0x14, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_SET_EVENT_CFG	DLN2_CMD(0x1E, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_GET_EVENT_CFG	DLN2_CMD(0x1F, DLN2_GPIO_ID)

#define DLN2_GPIO_EVENT_NONE		0
#define DLN2_GPIO_EVENT_CHANGE		1
#define DLN2_GPIO_EVENT_LVL_HIGH	2
#define DLN2_GPIO_EVENT_LVL_LOW		3
#define DLN2_GPIO_EVENT_CHANGE_RISING	0x11
#define DLN2_GPIO_EVENT_CHANGE_FALLING  0x21
#define DLN2_GPIO_EVENT_MASK		0x0F

#define DLN2_GPIO_MAX_PINS 32

struct dln2_gpio {
	struct platform_device *pdev;
	struct gpio_chip gpio;

	/*
	 * Cache pin direction to save us one transfer, since the hardware has
	 * separate commands to read the in and out values.
	 */
	DECLARE_BITMAP(output_enabled, DLN2_GPIO_MAX_PINS);

	/* active IRQs - not synced to hardware */
	DECLARE_BITMAP(unmasked_irqs, DLN2_GPIO_MAX_PINS);
	/* active IRQS - synced to hardware */
	DECLARE_BITMAP(enabled_irqs, DLN2_GPIO_MAX_PINS);
	int irq_type[DLN2_GPIO_MAX_PINS];
	struct mutex irq_lock;
};

struct dln2_gpio_pin {
	__le16 pin;
};

struct dln2_gpio_pin_val {
	__le16 pin __packed;
	u8 value;
};

static int dln2_gpio_get_pin_count(struct platform_device *pdev)
{
	int ret;
	__le16 count;
	int len = sizeof(count);

	ret = dln2_transfer_rx(pdev, DLN2_GPIO_GET_PIN_COUNT, &count, &len);
	if (ret < 0)
		return ret;
	if (len < sizeof(count))
		return -EPROTO;

	return le16_to_cpu(count);
}

static int dln2_gpio_pin_cmd(struct dln2_gpio *dln2, int cmd, unsigned pin)
{
	struct dln2_gpio_pin req = {
		.pin = cpu_to_le16(pin),
	};

	return dln2_transfer_tx(dln2->pdev, cmd, &req, sizeof(req));
}

static int dln2_gpio_pin_val(struct dln2_gpio *dln2, int cmd, unsigned int pin)
{
	int ret;
	struct dln2_gpio_pin req = {
		.pin = cpu_to_le16(pin),
	};
	struct dln2_gpio_pin_val rsp;
	int len = sizeof(rsp);

	ret = dln2_transfer(dln2->pdev, cmd, &req, sizeof(req), &rsp, &len);
	if (ret < 0)
		return ret;
	if (len < sizeof(rsp) || req.pin != rsp.pin)
		return -EPROTO;

	return rsp.value;
}

static int dln2_gpio_pin_get_in_val(struct dln2_gpio *dln2, unsigned int pin)
{
	int ret;

	ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_VAL, pin);
	if (ret < 0)
		return ret;
	return !!ret;
}

static int dln2_gpio_pin_get_out_val(struct dln2_gpio *dln2, unsigned int pin)
{
	int ret;

	ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_OUT_VAL, pin);
	if (ret < 0)
		return ret;
	return !!ret;
}

static int dln2_gpio_pin_set_out_val(struct dln2_gpio *dln2,
				     unsigned int pin, int value)
{
	struct dln2_gpio_pin_val req = {
		.pin = cpu_to_le16(pin),
		.value = value,
	};

	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_OUT_VAL, &req,
				sizeof(req));
}

#define DLN2_GPIO_DIRECTION_IN		0
#define DLN2_GPIO_DIRECTION_OUT		1

static int dln2_gpio_request(struct gpio_chip *chip, unsigned offset)
{
	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	struct dln2_gpio_pin req = {
		.pin = cpu_to_le16(offset),
	};
	struct dln2_gpio_pin_val rsp;
	int len = sizeof(rsp);
	int ret;

	ret = dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_ENABLE, offset);
	if (ret < 0)
		return ret;

	/* cache the pin direction */
	ret = dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_GET_DIRECTION,
			    &req, sizeof(req), &rsp, &len);
	if (ret < 0)
		return ret;
	if (len < sizeof(rsp) || req.pin != rsp.pin) {
		ret = -EPROTO;
		goto out_disable;
	}

	switch (rsp.value) {
	case DLN2_GPIO_DIRECTION_IN:
		clear_bit(offset, dln2->output_enabled);
		return 0;
	case DLN2_GPIO_DIRECTION_OUT:
		set_bit(offset, dln2->output_enabled);
		return 0;
	default:
		ret = -EPROTO;
		goto out_disable;
	}

out_disable:
	dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
	return ret;
}

static void dln2_gpio_free(struct gpio_chip *chip, unsigned offset)
{
	struct dln2_gpio *dln2 = gpiochip_get_data(chip);

	dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
}

static int dln2_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
	struct dln2_gpio *dln2 = gpiochip_get_data(chip);

	if (test_bit(offset, dln2->output_enabled))
		return GPIO_LINE_DIRECTION_OUT;

	return GPIO_LINE_DIRECTION_IN;
}

static int dln2_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	int dir;

	dir = dln2_gpio_get_direction(chip, offset);
	if (dir < 0)
		return dir;

	if (dir == GPIO_LINE_DIRECTION_IN)
		return dln2_gpio_pin_get_in_val(dln2, offset);

	return dln2_gpio_pin_get_out_val(dln2, offset);
}

static int dln2_gpio_set(struct gpio_chip *chip, unsigned int offset,
			 int value)
{
	struct dln2_gpio *dln2 = gpiochip_get_data(chip);

	return dln2_gpio_pin_set_out_val(dln2, offset, value);
}

static int dln2_gpio_set_direction(struct gpio_chip *chip, unsigned offset,
				   unsigned dir)
{
	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	struct dln2_gpio_pin_val req = {
		.pin = cpu_to_le16(offset),
		.value = dir,
	};
	int ret;

	ret = dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_DIRECTION,
			       &req, sizeof(req));
	if (ret < 0)
		return ret;

	if (dir == DLN2_GPIO_DIRECTION_OUT)
		set_bit(offset, dln2->output_enabled);
	else
		clear_bit(offset, dln2->output_enabled);

	return ret;
}

static int dln2_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_IN);
}

static int dln2_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
				      int value)
{
	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	int ret;

	ret = dln2_gpio_pin_set_out_val(dln2, offset, value);
	if (ret < 0)
		return ret;

	return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_OUT);
}

static int dln2_gpio_set_config(struct gpio_chip *chip, unsigned offset,
				unsigned long config)
{
	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	__le32 duration;

	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
		return -ENOTSUPP;

	duration = cpu_to_le32(pinconf_to_config_argument(config));
	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_SET_DEBOUNCE,
				&duration, sizeof(duration));
}

static int dln2_gpio_set_event_cfg(struct dln2_gpio *dln2, unsigned pin,
				   unsigned type, unsigned period)
{
	struct {
		__le16 pin;
		u8 type;
		__le16 period;
	} __packed req = {
		.pin = cpu_to_le16(pin),
		.type = type,
		.period = cpu_to_le16(period),
	};

	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_EVENT_CFG,
				&req, sizeof(req));
}

static void dln2_irq_unmask(struct irq_data *irqd)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	int pin = irqd_to_hwirq(irqd);

	gpiochip_enable_irq(gc, pin);
	set_bit(pin, dln2->unmasked_irqs);
}

static void dln2_irq_mask(struct irq_data *irqd)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	int pin = irqd_to_hwirq(irqd);

	clear_bit(pin, dln2->unmasked_irqs);
	gpiochip_disable_irq(gc, pin);
}

static int dln2_irq_set_type(struct irq_data *irqd, unsigned type)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	int pin = irqd_to_hwirq(irqd);

	switch (type) {
	case IRQ_TYPE_LEVEL_HIGH:
		dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_HIGH;
		break;
	case IRQ_TYPE_LEVEL_LOW:
		dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_LOW;
		break;
	case IRQ_TYPE_EDGE_BOTH:
		dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE;
		break;
	case IRQ_TYPE_EDGE_RISING:
		dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_RISING;
		break;
	case IRQ_TYPE_EDGE_FALLING:
		dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_FALLING;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static void dln2_irq_bus_lock(struct irq_data *irqd)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct dln2_gpio *dln2 = gpiochip_get_data(gc);

	mutex_lock(&dln2->irq_lock);
}

static void dln2_irq_bus_unlock(struct irq_data *irqd)
{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	int pin = irqd_to_hwirq(irqd);
	int enabled, unmasked;
	unsigned type;
	int ret;

	enabled = test_bit(pin, dln2->enabled_irqs);
	unmasked = test_bit(pin, dln2->unmasked_irqs);

	if (enabled != unmasked) {
		if (unmasked) {
			type = dln2->irq_type[pin] & DLN2_GPIO_EVENT_MASK;
			set_bit(pin, dln2->enabled_irqs);
		} else {
			type = DLN2_GPIO_EVENT_NONE;
			clear_bit(pin, dln2->enabled_irqs);
		}

		ret = dln2_gpio_set_event_cfg(dln2, pin, type, 0);
		if (ret)
			dev_err(dln2->gpio.parent, "failed to set event\n");
	}

	mutex_unlock(&dln2->irq_lock);
}

static const struct irq_chip dln2_irqchip = {
	.name = "dln2-irq",
	.irq_mask = dln2_irq_mask,
	.irq_unmask = dln2_irq_unmask,
	.irq_set_type = dln2_irq_set_type,
	.irq_bus_lock = dln2_irq_bus_lock,
	.irq_bus_sync_unlock = dln2_irq_bus_unlock,
	.flags = IRQCHIP_IMMUTABLE,
	GPIOCHIP_IRQ_RESOURCE_HELPERS,
};

static void dln2_gpio_event(struct platform_device *pdev, u16 echo,
			    const void *data, int len)
{
	int pin, ret;

	const struct {
		__le16 count;
		__u8 type;
		__le16 pin;
		__u8 value;
	} __packed *event = data;
	struct dln2_gpio *dln2 = platform_get_drvdata(pdev);

	if (len < sizeof(*event)) {
		dev_err(dln2->gpio.parent, "short event message\n");
		return;
	}

	pin = le16_to_cpu(event->pin);
	if (pin >= dln2->gpio.ngpio) {
		dev_err(dln2->gpio.parent, "out of bounds pin %d\n", pin);
		return;
	}

	switch (dln2->irq_type[pin]) {
	case DLN2_GPIO_EVENT_CHANGE_RISING:
		if (!event->value)
			return;
		break;
	case DLN2_GPIO_EVENT_CHANGE_FALLING:
		if (event->value)
			return;
		break;
	}

	ret = generic_handle_domain_irq(dln2->gpio.irq.domain, pin);
	if (unlikely(ret))
		dev_err(dln2->gpio.parent, "pin %d not mapped to IRQ\n", pin);
}

static int dln2_gpio_probe(struct platform_device *pdev)
{
	struct dln2_gpio *dln2;
	struct device *dev = &pdev->dev;
	struct gpio_irq_chip *girq;
	int pins;
	int ret;

	pins = dln2_gpio_get_pin_count(pdev);
	if (pins < 0) {
		dev_err(dev, "failed to get pin count: %d\n", pins);
		return pins;
	}
	if (pins > DLN2_GPIO_MAX_PINS) {
		pins = DLN2_GPIO_MAX_PINS;
		dev_warn(dev, "clamping pins to %d\n", DLN2_GPIO_MAX_PINS);
	}

	dln2 = devm_kzalloc(&pdev->dev, sizeof(*dln2), GFP_KERNEL);
	if (!dln2)
		return -ENOMEM;

	mutex_init(&dln2->irq_lock);

	dln2->pdev = pdev;

	dln2->gpio.label = "dln2";
	dln2->gpio.parent = dev;
	dln2->gpio.owner = THIS_MODULE;
	dln2->gpio.base = -1;
	dln2->gpio.ngpio = pins;
	dln2->gpio.can_sleep = true;
	dln2->gpio.set_rv = dln2_gpio_set;
	dln2->gpio.get = dln2_gpio_get;
	dln2->gpio.request = dln2_gpio_request;
	dln2->gpio.free = dln2_gpio_free;
	dln2->gpio.get_direction = dln2_gpio_get_direction;
	dln2->gpio.direction_input = dln2_gpio_direction_input;
	dln2->gpio.direction_output = dln2_gpio_direction_output;
	dln2->gpio.set_config = dln2_gpio_set_config;

	girq = &dln2->gpio.irq;
	gpio_irq_chip_set_chip(girq, &dln2_irqchip);
	/* The event comes from the outside so no parent handler */
	girq->parent_handler = NULL;
	girq->num_parents = 0;
	girq->parents = NULL;
	girq->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_simple_irq;

	platform_set_drvdata(pdev, dln2);

	ret = devm_gpiochip_add_data(dev, &dln2->gpio, dln2);
	if (ret < 0) {
		dev_err(dev, "failed to add gpio chip: %d\n", ret);
		return ret;
	}

	ret = dln2_register_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV,
				     dln2_gpio_event);
	if (ret) {
		dev_err(dev, "failed to register event cb: %d\n", ret);
		return ret;
	}

	return 0;
}

static void dln2_gpio_remove(struct platform_device *pdev)
{
	dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV);
}

static struct platform_driver dln2_gpio_driver = {
	.driver.name	= "dln2-gpio",
	.probe		= dln2_gpio_probe,
	.remove		= dln2_gpio_remove,
};

module_platform_driver(dln2_gpio_driver);

MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com");
MODULE_DESCRIPTION("Driver for the Diolan DLN2 GPIO interface");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:dln2-gpio");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* Driver for the Diolan DLN-2 USB-GPIO adapter
	4	*
	5	* Copyright (c) 2014 Intel Corporation
	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	10	#include <linux/slab.h>
	11	#include <linux/types.h>
	12	#include <linux/irqdomain.h>
	13	#include <linux/irq.h>
	14	#include <linux/irqchip/chained_irq.h>
	15	#include <linux/gpio/driver.h>
	16	#include <linux/platform_device.h>
	17	#include <linux/mfd/dln2.h>
	18
	19	#define DLN2_GPIO_ID 0x01
	20
	21	#define DLN2_GPIO_GET_PIN_COUNT DLN2_CMD(0x01, DLN2_GPIO_ID)
	22	#define DLN2_GPIO_SET_DEBOUNCE DLN2_CMD(0x04, DLN2_GPIO_ID)
	23	#define DLN2_GPIO_GET_DEBOUNCE DLN2_CMD(0x05, DLN2_GPIO_ID)
	24	#define DLN2_GPIO_PORT_GET_VAL DLN2_CMD(0x06, DLN2_GPIO_ID)
	25	#define DLN2_GPIO_PIN_GET_VAL DLN2_CMD(0x0B, DLN2_GPIO_ID)
	26	#define DLN2_GPIO_PIN_SET_OUT_VAL DLN2_CMD(0x0C, DLN2_GPIO_ID)
	27	#define DLN2_GPIO_PIN_GET_OUT_VAL DLN2_CMD(0x0D, DLN2_GPIO_ID)
	28	#define DLN2_GPIO_CONDITION_MET_EV DLN2_CMD(0x0F, DLN2_GPIO_ID)
	29	#define DLN2_GPIO_PIN_ENABLE DLN2_CMD(0x10, DLN2_GPIO_ID)
	30	#define DLN2_GPIO_PIN_DISABLE DLN2_CMD(0x11, DLN2_GPIO_ID)
	31	#define DLN2_GPIO_PIN_SET_DIRECTION DLN2_CMD(0x13, DLN2_GPIO_ID)
	32	#define DLN2_GPIO_PIN_GET_DIRECTION DLN2_CMD(0x14, DLN2_GPIO_ID)
	33	#define DLN2_GPIO_PIN_SET_EVENT_CFG DLN2_CMD(0x1E, DLN2_GPIO_ID)
	34	#define DLN2_GPIO_PIN_GET_EVENT_CFG DLN2_CMD(0x1F, DLN2_GPIO_ID)
	35
	36	#define DLN2_GPIO_EVENT_NONE 0
	37	#define DLN2_GPIO_EVENT_CHANGE 1
	38	#define DLN2_GPIO_EVENT_LVL_HIGH 2
	39	#define DLN2_GPIO_EVENT_LVL_LOW 3
	40	#define DLN2_GPIO_EVENT_CHANGE_RISING 0x11
	41	#define DLN2_GPIO_EVENT_CHANGE_FALLING 0x21
	42	#define DLN2_GPIO_EVENT_MASK 0x0F
	43
	44	#define DLN2_GPIO_MAX_PINS 32
	45
	46	struct dln2_gpio {
	47	struct platform_device *pdev;
	48	struct gpio_chip gpio;
	49
	50	/*
	51	* Cache pin direction to save us one transfer, since the hardware has
	52	* separate commands to read the in and out values.
	53	*/
	54	DECLARE_BITMAP(output_enabled, DLN2_GPIO_MAX_PINS);
	55
	56	/* active IRQs - not synced to hardware */
	57	DECLARE_BITMAP(unmasked_irqs, DLN2_GPIO_MAX_PINS);
	58	/* active IRQS - synced to hardware */
	59	DECLARE_BITMAP(enabled_irqs, DLN2_GPIO_MAX_PINS);
	60	int irq_type[DLN2_GPIO_MAX_PINS];
	61	struct mutex irq_lock;
	62	};
	63
	64	struct dln2_gpio_pin {
	65	__le16 pin;
	66	};
	67
	68	struct dln2_gpio_pin_val {
	69	__le16 pin __packed;
	70	u8 value;
	71	};
	72
	73	static int dln2_gpio_get_pin_count(struct platform_device *pdev)
	74	{
	75	int ret;
	76	__le16 count;
	77	int len = sizeof(count);
	78
	79	ret = dln2_transfer_rx(pdev, DLN2_GPIO_GET_PIN_COUNT, &count, &len);
	80	if (ret < 0)
	81	return ret;
	82	if (len < sizeof(count))
	83	return -EPROTO;
	84
	85	return le16_to_cpu(count);
	86	}
	87
	88	static int dln2_gpio_pin_cmd(struct dln2_gpio *dln2, int cmd, unsigned pin)
	89	{
	90	struct dln2_gpio_pin req = {
	91	.pin = cpu_to_le16(pin),
	92	};
	93
	94	return dln2_transfer_tx(dln2->pdev, cmd, &req, sizeof(req));
	95	}
	96
	97	static int dln2_gpio_pin_val(struct dln2_gpio *dln2, int cmd, unsigned int pin)
	98	{
	99	int ret;
	100	struct dln2_gpio_pin req = {
	101	.pin = cpu_to_le16(pin),
	102	};
	103	struct dln2_gpio_pin_val rsp;
	104	int len = sizeof(rsp);
	105
	106	ret = dln2_transfer(dln2->pdev, cmd, &req, sizeof(req), &rsp, &len);
	107	if (ret < 0)
	108	return ret;
	109	if (len < sizeof(rsp) \|\| req.pin != rsp.pin)
	110	return -EPROTO;
	111
	112	return rsp.value;
	113	}
	114
	115	static int dln2_gpio_pin_get_in_val(struct dln2_gpio *dln2, unsigned int pin)
	116	{
	117	int ret;
	118
	119	ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_VAL, pin);
	120	if (ret < 0)
	121	return ret;
	122	return !!ret;
	123	}
	124
	125	static int dln2_gpio_pin_get_out_val(struct dln2_gpio *dln2, unsigned int pin)
	126	{
	127	int ret;
	128
	129	ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_OUT_VAL, pin);
	130	if (ret < 0)
	131	return ret;
	132	return !!ret;
	133	}
	134
	135	static int dln2_gpio_pin_set_out_val(struct dln2_gpio *dln2,
	136	unsigned int pin, int value)
	137	{
	138	struct dln2_gpio_pin_val req = {
	139	.pin = cpu_to_le16(pin),
	140	.value = value,
	141	};
	142
	143	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_OUT_VAL, &req,
	144	sizeof(req));
	145	}
	146
	147	#define DLN2_GPIO_DIRECTION_IN 0
	148	#define DLN2_GPIO_DIRECTION_OUT 1
	149
	150	static int dln2_gpio_request(struct gpio_chip *chip, unsigned offset)
	151	{
	152	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	153	struct dln2_gpio_pin req = {
	154	.pin = cpu_to_le16(offset),
	155	};
	156	struct dln2_gpio_pin_val rsp;
	157	int len = sizeof(rsp);
	158	int ret;
	159
	160	ret = dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_ENABLE, offset);
	161	if (ret < 0)
	162	return ret;
	163
	164	/* cache the pin direction */
	165	ret = dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_GET_DIRECTION,
	166	&req, sizeof(req), &rsp, &len);
	167	if (ret < 0)
	168	return ret;
	169	if (len < sizeof(rsp) \|\| req.pin != rsp.pin) {
	170	ret = -EPROTO;
	171	goto out_disable;
	172	}
	173
	174	switch (rsp.value) {
	175	case DLN2_GPIO_DIRECTION_IN:
	176	clear_bit(offset, dln2->output_enabled);
	177	return 0;
	178	case DLN2_GPIO_DIRECTION_OUT:
	179	set_bit(offset, dln2->output_enabled);
	180	return 0;
	181	default:
	182	ret = -EPROTO;
	183	goto out_disable;
	184	}
	185
	186	out_disable:
	187	dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
	188	return ret;
	189	}
	190
	191	static void dln2_gpio_free(struct gpio_chip *chip, unsigned offset)
	192	{
	193	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	194
	195	dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
	196	}
	197
	198	static int dln2_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
	199	{
	200	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	201
	202	if (test_bit(offset, dln2->output_enabled))
	203	return GPIO_LINE_DIRECTION_OUT;
	204
	205	return GPIO_LINE_DIRECTION_IN;
	206	}
	207
	208	static int dln2_gpio_get(struct gpio_chip *chip, unsigned int offset)
	209	{
	210	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	211	int dir;
	212
	213	dir = dln2_gpio_get_direction(chip, offset);
	214	if (dir < 0)
	215	return dir;
	216
	217	if (dir == GPIO_LINE_DIRECTION_IN)
	218	return dln2_gpio_pin_get_in_val(dln2, offset);
	219
	220	return dln2_gpio_pin_get_out_val(dln2, offset);
	221	}
	222
	223	static int dln2_gpio_set(struct gpio_chip *chip, unsigned int offset,
	224	int value)
	225	{
	226	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	227
	228	return dln2_gpio_pin_set_out_val(dln2, offset, value);
	229	}
	230
	231	static int dln2_gpio_set_direction(struct gpio_chip *chip, unsigned offset,
	232	unsigned dir)
	233	{
	234	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	235	struct dln2_gpio_pin_val req = {
	236	.pin = cpu_to_le16(offset),
	237	.value = dir,
	238	};
	239	int ret;
	240
	241	ret = dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_DIRECTION,
	242	&req, sizeof(req));
	243	if (ret < 0)
	244	return ret;
	245
	246	if (dir == DLN2_GPIO_DIRECTION_OUT)
	247	set_bit(offset, dln2->output_enabled);
	248	else
	249	clear_bit(offset, dln2->output_enabled);
	250
	251	return ret;
	252	}
	253
	254	static int dln2_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
	255	{
	256	return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_IN);
	257	}
	258
	259	static int dln2_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
	260	int value)
	261	{
	262	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	263	int ret;
	264
	265	ret = dln2_gpio_pin_set_out_val(dln2, offset, value);
	266	if (ret < 0)
	267	return ret;
	268
	269	return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_OUT);
	270	}
	271
	272	static int dln2_gpio_set_config(struct gpio_chip *chip, unsigned offset,
	273	unsigned long config)
	274	{
	275	struct dln2_gpio *dln2 = gpiochip_get_data(chip);
	276	__le32 duration;
	277
	278	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
	279	return -ENOTSUPP;
	280
	281	duration = cpu_to_le32(pinconf_to_config_argument(config));
	282	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_SET_DEBOUNCE,
	283	&duration, sizeof(duration));
	284	}
	285
	286	static int dln2_gpio_set_event_cfg(struct dln2_gpio *dln2, unsigned pin,
	287	unsigned type, unsigned period)
	288	{
	289	struct {
	290	__le16 pin;
	291	u8 type;
	292	__le16 period;
	293	} __packed req = {
	294	.pin = cpu_to_le16(pin),
	295	.type = type,
	296	.period = cpu_to_le16(period),
	297	};
	298
	299	return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_EVENT_CFG,
	300	&req, sizeof(req));
	301	}
	302
	303	static void dln2_irq_unmask(struct irq_data *irqd)
	304	{
	305	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	306	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	307	int pin = irqd_to_hwirq(irqd);
	308
	309	gpiochip_enable_irq(gc, pin);
	310	set_bit(pin, dln2->unmasked_irqs);
	311	}
	312
	313	static void dln2_irq_mask(struct irq_data *irqd)
	314	{
	315	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	316	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	317	int pin = irqd_to_hwirq(irqd);
	318
	319	clear_bit(pin, dln2->unmasked_irqs);
	320	gpiochip_disable_irq(gc, pin);
	321	}
	322
	323	static int dln2_irq_set_type(struct irq_data *irqd, unsigned type)
	324	{
	325	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	326	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	327	int pin = irqd_to_hwirq(irqd);
	328
	329	switch (type) {
	330	case IRQ_TYPE_LEVEL_HIGH:
	331	dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_HIGH;
	332	break;
	333	case IRQ_TYPE_LEVEL_LOW:
	334	dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_LOW;
	335	break;
	336	case IRQ_TYPE_EDGE_BOTH:
	337	dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE;
	338	break;
	339	case IRQ_TYPE_EDGE_RISING:
	340	dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_RISING;
	341	break;
	342	case IRQ_TYPE_EDGE_FALLING:
	343	dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_FALLING;
	344	break;
	345	default:
	346	return -EINVAL;
	347	}
	348
	349	return 0;
	350	}
	351
	352	static void dln2_irq_bus_lock(struct irq_data *irqd)
	353	{
	354	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	355	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	356
	357	mutex_lock(&dln2->irq_lock);
	358	}
	359
	360	static void dln2_irq_bus_unlock(struct irq_data *irqd)
	361	{
	362	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
	363	struct dln2_gpio *dln2 = gpiochip_get_data(gc);
	364	int pin = irqd_to_hwirq(irqd);
	365	int enabled, unmasked;
	366	unsigned type;
	367	int ret;
	368
	369	enabled = test_bit(pin, dln2->enabled_irqs);
	370	unmasked = test_bit(pin, dln2->unmasked_irqs);
	371
	372	if (enabled != unmasked) {
	373	if (unmasked) {
	374	type = dln2->irq_type[pin] & DLN2_GPIO_EVENT_MASK;
	375	set_bit(pin, dln2->enabled_irqs);
	376	} else {
	377	type = DLN2_GPIO_EVENT_NONE;
	378	clear_bit(pin, dln2->enabled_irqs);
	379	}
	380
	381	ret = dln2_gpio_set_event_cfg(dln2, pin, type, 0);
	382	if (ret)
	383	dev_err(dln2->gpio.parent, "failed to set event\n");
	384	}
	385
	386	mutex_unlock(&dln2->irq_lock);
	387	}
	388
	389	static const struct irq_chip dln2_irqchip = {
	390	.name = "dln2-irq",
	391	.irq_mask = dln2_irq_mask,
	392	.irq_unmask = dln2_irq_unmask,
	393	.irq_set_type = dln2_irq_set_type,
	394	.irq_bus_lock = dln2_irq_bus_lock,
	395	.irq_bus_sync_unlock = dln2_irq_bus_unlock,
	396	.flags = IRQCHIP_IMMUTABLE,
	397	GPIOCHIP_IRQ_RESOURCE_HELPERS,
	398	};
	399
	400	static void dln2_gpio_event(struct platform_device *pdev, u16 echo,
	401	const void *data, int len)
	402	{
	403	int pin, ret;
	404
	405	const struct {
	406	__le16 count;
	407	__u8 type;
	408	__le16 pin;
	409	__u8 value;
	410	} __packed *event = data;
	411	struct dln2_gpio *dln2 = platform_get_drvdata(pdev);
	412
	413	if (len < sizeof(*event)) {
	414	dev_err(dln2->gpio.parent, "short event message\n");
	415	return;
	416	}
	417
	418	pin = le16_to_cpu(event->pin);
	419	if (pin >= dln2->gpio.ngpio) {
	420	dev_err(dln2->gpio.parent, "out of bounds pin %d\n", pin);
	421	return;
	422	}
	423
	424	switch (dln2->irq_type[pin]) {
	425	case DLN2_GPIO_EVENT_CHANGE_RISING:
	426	if (!event->value)
	427	return;
	428	break;
	429	case DLN2_GPIO_EVENT_CHANGE_FALLING:
	430	if (event->value)
	431	return;
	432	break;
	433	}
	434
	435	ret = generic_handle_domain_irq(dln2->gpio.irq.domain, pin);
	436	if (unlikely(ret))
	437	dev_err(dln2->gpio.parent, "pin %d not mapped to IRQ\n", pin);
	438	}
	439
	440	static int dln2_gpio_probe(struct platform_device *pdev)
	441	{
	442	struct dln2_gpio *dln2;
	443	struct device *dev = &pdev->dev;
	444	struct gpio_irq_chip *girq;
	445	int pins;
	446	int ret;
	447
	448	pins = dln2_gpio_get_pin_count(pdev);
	449	if (pins < 0) {
	450	dev_err(dev, "failed to get pin count: %d\n", pins);
	451	return pins;
	452	}
	453	if (pins > DLN2_GPIO_MAX_PINS) {
	454	pins = DLN2_GPIO_MAX_PINS;
	455	dev_warn(dev, "clamping pins to %d\n", DLN2_GPIO_MAX_PINS);
	456	}
	457
	458	dln2 = devm_kzalloc(&pdev->dev, sizeof(*dln2), GFP_KERNEL);
	459	if (!dln2)
	460	return -ENOMEM;
	461
	462	mutex_init(&dln2->irq_lock);
	463
	464	dln2->pdev = pdev;
	465
	466	dln2->gpio.label = "dln2";
	467	dln2->gpio.parent = dev;
	468	dln2->gpio.owner = THIS_MODULE;
	469	dln2->gpio.base = -1;
	470	dln2->gpio.ngpio = pins;
	471	dln2->gpio.can_sleep = true;
	472	dln2->gpio.set_rv = dln2_gpio_set;
	473	dln2->gpio.get = dln2_gpio_get;
	474	dln2->gpio.request = dln2_gpio_request;
	475	dln2->gpio.free = dln2_gpio_free;
	476	dln2->gpio.get_direction = dln2_gpio_get_direction;
	477	dln2->gpio.direction_input = dln2_gpio_direction_input;
	478	dln2->gpio.direction_output = dln2_gpio_direction_output;
	479	dln2->gpio.set_config = dln2_gpio_set_config;
	480
	481	girq = &dln2->gpio.irq;
	482	gpio_irq_chip_set_chip(girq, &dln2_irqchip);
	483	/* The event comes from the outside so no parent handler */
	484	girq->parent_handler = NULL;
	485	girq->num_parents = 0;
	486	girq->parents = NULL;
	487	girq->default_type = IRQ_TYPE_NONE;
	488	girq->handler = handle_simple_irq;
	489
	490	platform_set_drvdata(pdev, dln2);
	491
	492	ret = devm_gpiochip_add_data(dev, &dln2->gpio, dln2);
	493	if (ret < 0) {
	494	dev_err(dev, "failed to add gpio chip: %d\n", ret);
	495	return ret;
	496	}
	497
	498	ret = dln2_register_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV,
	499	dln2_gpio_event);
	500	if (ret) {
	501	dev_err(dev, "failed to register event cb: %d\n", ret);
	502	return ret;
	503	}
	504
	505	return 0;
	506	}
	507
	508	static void dln2_gpio_remove(struct platform_device *pdev)
	509	{
	510	dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV);
	511	}
	512
	513	static struct platform_driver dln2_gpio_driver = {
	514	.driver.name = "dln2-gpio",
	515	.probe = dln2_gpio_probe,
	516	.remove = dln2_gpio_remove,
	517	};
	518
	519	module_platform_driver(dln2_gpio_driver);
	520
	521	MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com");
	522	MODULE_DESCRIPTION("Driver for the Diolan DLN2 GPIO interface");
	523	MODULE_LICENSE("GPL v2");
	524	MODULE_ALIAS("platform:dln2-gpio");