diff options
Diffstat (limited to 'drivers/gpio/gpio-siox.c')
| -rw-r--r-- | drivers/gpio/gpio-siox.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-siox.c b/drivers/gpio/gpio-siox.c new file mode 100644 index 0000000000..051bc99bdf --- /dev/null +++ b/drivers/gpio/gpio-siox.c @@ -0,0 +1,270 @@ +// 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 mutex lock; + u8 setdata[1]; + u8 getdata[3]; + + raw_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); + + raw_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; + + raw_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. + */ + raw_spin_lock_irq(&ddata->irqlock); + ddata->irq_status &= ~(1 << offset); + raw_spin_unlock_irq(&ddata->irqlock); + + handle_nested_irq(irq); + } + } + + return 0; +} + +static void gpio_siox_irq_ack(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gpio_siox_ddata *ddata = gpiochip_get_data(gc); + + raw_spin_lock(&ddata->irqlock); + ddata->irq_status &= ~(1 << d->hwirq); + raw_spin_unlock(&ddata->irqlock); +} + +static void gpio_siox_irq_mask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gpio_siox_ddata *ddata = gpiochip_get_data(gc); + + raw_spin_lock(&ddata->irqlock); + ddata->irq_enable &= ~(1 << d->hwirq); + raw_spin_unlock(&ddata->irqlock); + gpiochip_disable_irq(gc, irqd_to_hwirq(d)); +} + +static void gpio_siox_irq_unmask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gpio_siox_ddata *ddata = gpiochip_get_data(gc); + + gpiochip_enable_irq(gc, irqd_to_hwirq(d)); + raw_spin_lock(&ddata->irqlock); + ddata->irq_enable |= 1 << d->hwirq; + raw_spin_unlock(&ddata->irqlock); +} + +static int gpio_siox_irq_set_type(struct irq_data *d, u32 type) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct gpio_siox_ddata *ddata = gpiochip_get_data(gc); + + raw_spin_lock(&ddata->irqlock); + ddata->irq_type[d->hwirq] = type; + raw_spin_unlock(&ddata->irqlock); + + return 0; +} + +static int gpio_siox_get(struct gpio_chip *chip, unsigned int offset) +{ + struct gpio_siox_ddata *ddata = gpiochip_get_data(chip); + 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 = gpiochip_get_data(chip); + 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 GPIO_LINE_DIRECTION_IN; + else + return GPIO_LINE_DIRECTION_OUT; +} + +static const struct irq_chip gpio_siox_irq_chip = { + .name = "siox-gpio", + .irq_ack = gpio_siox_irq_ack, + .irq_mask = gpio_siox_irq_mask, + .irq_unmask = gpio_siox_irq_unmask, + .irq_set_type = gpio_siox_irq_set_type, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + +static int gpio_siox_probe(struct siox_device *sdevice) +{ + struct gpio_siox_ddata *ddata; + struct gpio_irq_chip *girq; + struct device *dev = &sdevice->dev; + struct gpio_chip *gc; + int ret; + + ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL); + if (!ddata) + return -ENOMEM; + + dev_set_drvdata(dev, ddata); + + mutex_init(&ddata->lock); + raw_spin_lock_init(&ddata->irqlock); + + gc = &ddata->gchip; + gc->base = -1; + gc->can_sleep = 1; + gc->parent = dev; + gc->owner = THIS_MODULE; + gc->get = gpio_siox_get; + gc->set = gpio_siox_set; + gc->direction_input = gpio_siox_direction_input; + gc->direction_output = gpio_siox_direction_output; + gc->get_direction = gpio_siox_get_direction; + gc->ngpio = 20; + + girq = &gc->irq; + gpio_irq_chip_set_chip(girq, &gpio_siox_irq_chip); + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_level_irq; + girq->threaded = true; + + ret = devm_gpiochip_add_data(dev, gc, ddata); + if (ret) + dev_err(dev, "Failed to register gpio chip (%d)\n", ret); + + return ret; +} + +static struct siox_driver gpio_siox_driver = { + .probe = gpio_siox_probe, + .set_data = gpio_siox_set_data, + .get_data = gpio_siox_get_data, + .driver = { + .name = "gpio-siox", + }, +}; +module_siox_driver(gpio_siox_driver); + +MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>"); +MODULE_DESCRIPTION("SIOX gpio driver"); +MODULE_LICENSE("GPL v2"); |