linux/drivers/gpio/gpio-siox.c
Uwe Kleine-König be8c8facc7 gpio: new driver to work with a 8x12 siox
This driver controls a SIOX device that provides 20 I/O lines. The first
twelve are fixed inputs, the remaining eight are outputs.

Acked-by: Gavin Schenk <g.schenk@eckelmann.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-09-28 09:30:42 +02:00

294 lines
6.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2015-2018 Pengutronix, Uwe Kleine-König <kernel@pengutronix.de>
*/
#include <linux/module.h>
#include <linux/siox.h>
#include <linux/gpio/driver.h>
#include <linux/of.h>
struct gpio_siox_ddata {
struct gpio_chip gchip;
struct irq_chip ichip;
struct mutex lock;
u8 setdata[1];
u8 getdata[3];
spinlock_t irqlock;
u32 irq_enable;
u32 irq_status;
u32 irq_type[20];
};
/*
* Note that this callback only sets the value that is clocked out in the next
* cycle.
*/
static int gpio_siox_set_data(struct siox_device *sdevice, u8 status, u8 buf[])
{
struct gpio_siox_ddata *ddata = dev_get_drvdata(&sdevice->dev);
mutex_lock(&ddata->lock);
buf[0] = ddata->setdata[0];
mutex_unlock(&ddata->lock);
return 0;
}
static int gpio_siox_get_data(struct siox_device *sdevice, const u8 buf[])
{
struct gpio_siox_ddata *ddata = dev_get_drvdata(&sdevice->dev);
size_t offset;
u32 trigger;
mutex_lock(&ddata->lock);
spin_lock_irq(&ddata->irqlock);
for (offset = 0; offset < 12; ++offset) {
unsigned int bitpos = 11 - offset;
unsigned int gpiolevel = buf[bitpos / 8] & (1 << bitpos % 8);
unsigned int prev_level =
ddata->getdata[bitpos / 8] & (1 << (bitpos % 8));
u32 irq_type = ddata->irq_type[offset];
if (gpiolevel) {
if ((irq_type & IRQ_TYPE_LEVEL_HIGH) ||
((irq_type & IRQ_TYPE_EDGE_RISING) && !prev_level))
ddata->irq_status |= 1 << offset;
} else {
if ((irq_type & IRQ_TYPE_LEVEL_LOW) ||
((irq_type & IRQ_TYPE_EDGE_FALLING) && prev_level))
ddata->irq_status |= 1 << offset;
}
}
trigger = ddata->irq_status & ddata->irq_enable;
spin_unlock_irq(&ddata->irqlock);
ddata->getdata[0] = buf[0];
ddata->getdata[1] = buf[1];
ddata->getdata[2] = buf[2];
mutex_unlock(&ddata->lock);
for (offset = 0; offset < 12; ++offset) {
if (trigger & (1 << offset)) {
struct irq_domain *irqdomain = ddata->gchip.irq.domain;
unsigned int irq = irq_find_mapping(irqdomain, offset);
/*
* Conceptually handle_nested_irq should call the flow
* handler of the irq chip. But it doesn't, so we have
* to clean the irq_status here.
*/
spin_lock_irq(&ddata->irqlock);
ddata->irq_status &= ~(1 << offset);
spin_unlock_irq(&ddata->irqlock);
handle_nested_irq(irq);
}
}
return 0;
}
static void gpio_siox_irq_ack(struct irq_data *d)
{
struct irq_chip *ic = irq_data_get_irq_chip(d);
struct gpio_siox_ddata *ddata =
container_of(ic, struct gpio_siox_ddata, ichip);
spin_lock_irq(&ddata->irqlock);
ddata->irq_status &= ~(1 << d->hwirq);
spin_unlock_irq(&ddata->irqlock);
}
static void gpio_siox_irq_mask(struct irq_data *d)
{
struct irq_chip *ic = irq_data_get_irq_chip(d);
struct gpio_siox_ddata *ddata =
container_of(ic, struct gpio_siox_ddata, ichip);
spin_lock_irq(&ddata->irqlock);
ddata->irq_enable &= ~(1 << d->hwirq);
spin_unlock_irq(&ddata->irqlock);
}
static void gpio_siox_irq_unmask(struct irq_data *d)
{
struct irq_chip *ic = irq_data_get_irq_chip(d);
struct gpio_siox_ddata *ddata =
container_of(ic, struct gpio_siox_ddata, ichip);
spin_lock_irq(&ddata->irqlock);
ddata->irq_enable |= 1 << d->hwirq;
spin_unlock_irq(&ddata->irqlock);
}
static int gpio_siox_irq_set_type(struct irq_data *d, u32 type)
{
struct irq_chip *ic = irq_data_get_irq_chip(d);
struct gpio_siox_ddata *ddata =
container_of(ic, struct gpio_siox_ddata, ichip);
spin_lock_irq(&ddata->irqlock);
ddata->irq_type[d->hwirq] = type;
spin_unlock_irq(&ddata->irqlock);
return 0;
}
static int gpio_siox_get(struct gpio_chip *chip, unsigned int offset)
{
struct gpio_siox_ddata *ddata =
container_of(chip, struct gpio_siox_ddata, gchip);
int ret;
mutex_lock(&ddata->lock);
if (offset >= 12) {
unsigned int bitpos = 19 - offset;
ret = ddata->setdata[0] & (1 << bitpos);
} else {
unsigned int bitpos = 11 - offset;
ret = ddata->getdata[bitpos / 8] & (1 << (bitpos % 8));
}
mutex_unlock(&ddata->lock);
return ret;
}
static void gpio_siox_set(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct gpio_siox_ddata *ddata =
container_of(chip, struct gpio_siox_ddata, gchip);
u8 mask = 1 << (19 - offset);
mutex_lock(&ddata->lock);
if (value)
ddata->setdata[0] |= mask;
else
ddata->setdata[0] &= ~mask;
mutex_unlock(&ddata->lock);
}
static int gpio_siox_direction_input(struct gpio_chip *chip,
unsigned int offset)
{
if (offset >= 12)
return -EINVAL;
return 0;
}
static int gpio_siox_direction_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
if (offset < 12)
return -EINVAL;
gpio_siox_set(chip, offset, value);
return 0;
}
static int gpio_siox_get_direction(struct gpio_chip *chip, unsigned int offset)
{
if (offset < 12)
return 1; /* input */
else
return 0; /* output */
}
static int gpio_siox_probe(struct siox_device *sdevice)
{
struct gpio_siox_ddata *ddata;
int ret;
ddata = devm_kzalloc(&sdevice->dev, sizeof(*ddata), GFP_KERNEL);
if (!ddata)
return -ENOMEM;
dev_set_drvdata(&sdevice->dev, ddata);
mutex_init(&ddata->lock);
spin_lock_init(&ddata->irqlock);
ddata->gchip.base = -1;
ddata->gchip.can_sleep = 1;
ddata->gchip.parent = &sdevice->dev;
ddata->gchip.owner = THIS_MODULE;
ddata->gchip.get = gpio_siox_get;
ddata->gchip.set = gpio_siox_set;
ddata->gchip.direction_input = gpio_siox_direction_input;
ddata->gchip.direction_output = gpio_siox_direction_output;
ddata->gchip.get_direction = gpio_siox_get_direction;
ddata->gchip.ngpio = 20;
ddata->ichip.name = "siox-gpio";
ddata->ichip.irq_ack = gpio_siox_irq_ack;
ddata->ichip.irq_mask = gpio_siox_irq_mask;
ddata->ichip.irq_unmask = gpio_siox_irq_unmask;
ddata->ichip.irq_set_type = gpio_siox_irq_set_type;
ret = gpiochip_add(&ddata->gchip);
if (ret) {
dev_err(&sdevice->dev,
"Failed to register gpio chip (%d)\n", ret);
goto err_gpiochip;
}
ret = gpiochip_irqchip_add(&ddata->gchip, &ddata->ichip,
0, handle_level_irq, IRQ_TYPE_EDGE_RISING);
if (ret) {
dev_err(&sdevice->dev,
"Failed to register irq chip (%d)\n", ret);
err_gpiochip:
gpiochip_remove(&ddata->gchip);
}
return ret;
}
static int gpio_siox_remove(struct siox_device *sdevice)
{
struct gpio_siox_ddata *ddata = dev_get_drvdata(&sdevice->dev);
gpiochip_remove(&ddata->gchip);
return 0;
}
static struct siox_driver gpio_siox_driver = {
.probe = gpio_siox_probe,
.remove = gpio_siox_remove,
.set_data = gpio_siox_set_data,
.get_data = gpio_siox_get_data,
.driver = {
.name = "gpio-siox",
},
};
static int __init gpio_siox_init(void)
{
return siox_driver_register(&gpio_siox_driver);
}
module_init(gpio_siox_init);
static void __exit gpio_siox_exit(void)
{
siox_driver_unregister(&gpio_siox_driver);
}
module_exit(gpio_siox_exit);
MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
MODULE_DESCRIPTION("SIOX gpio driver");
MODULE_LICENSE("GPL v2");