diff options
Diffstat (limited to 'drivers/gpio/gpio-sifive.c')
| -rw-r--r-- | drivers/gpio/gpio-sifive.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-sifive.c b/drivers/gpio/gpio-sifive.c new file mode 100644 index 0000000000..8decd9b5d2 --- /dev/null +++ b/drivers/gpio/gpio-sifive.c @@ -0,0 +1,274 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 SiFive + */ + +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/gpio/driver.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/regmap.h> + +#define SIFIVE_GPIO_INPUT_VAL 0x00 +#define SIFIVE_GPIO_INPUT_EN 0x04 +#define SIFIVE_GPIO_OUTPUT_EN 0x08 +#define SIFIVE_GPIO_OUTPUT_VAL 0x0C +#define SIFIVE_GPIO_RISE_IE 0x18 +#define SIFIVE_GPIO_RISE_IP 0x1C +#define SIFIVE_GPIO_FALL_IE 0x20 +#define SIFIVE_GPIO_FALL_IP 0x24 +#define SIFIVE_GPIO_HIGH_IE 0x28 +#define SIFIVE_GPIO_HIGH_IP 0x2C +#define SIFIVE_GPIO_LOW_IE 0x30 +#define SIFIVE_GPIO_LOW_IP 0x34 +#define SIFIVE_GPIO_OUTPUT_XOR 0x40 + +#define SIFIVE_GPIO_MAX 32 + +struct sifive_gpio { + void __iomem *base; + struct gpio_chip gc; + struct regmap *regs; + unsigned long irq_state; + unsigned int trigger[SIFIVE_GPIO_MAX]; + unsigned int irq_number[SIFIVE_GPIO_MAX]; +}; + +static void sifive_gpio_set_ie(struct sifive_gpio *chip, unsigned int offset) +{ + unsigned long flags; + unsigned int trigger; + + raw_spin_lock_irqsave(&chip->gc.bgpio_lock, flags); + trigger = (chip->irq_state & BIT(offset)) ? chip->trigger[offset] : 0; + regmap_update_bits(chip->regs, SIFIVE_GPIO_RISE_IE, BIT(offset), + (trigger & IRQ_TYPE_EDGE_RISING) ? BIT(offset) : 0); + regmap_update_bits(chip->regs, SIFIVE_GPIO_FALL_IE, BIT(offset), + (trigger & IRQ_TYPE_EDGE_FALLING) ? BIT(offset) : 0); + regmap_update_bits(chip->regs, SIFIVE_GPIO_HIGH_IE, BIT(offset), + (trigger & IRQ_TYPE_LEVEL_HIGH) ? BIT(offset) : 0); + regmap_update_bits(chip->regs, SIFIVE_GPIO_LOW_IE, BIT(offset), + (trigger & IRQ_TYPE_LEVEL_LOW) ? BIT(offset) : 0); + raw_spin_unlock_irqrestore(&chip->gc.bgpio_lock, flags); +} + +static int sifive_gpio_irq_set_type(struct irq_data *d, unsigned int trigger) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct sifive_gpio *chip = gpiochip_get_data(gc); + int offset = irqd_to_hwirq(d); + + if (offset < 0 || offset >= gc->ngpio) + return -EINVAL; + + chip->trigger[offset] = trigger; + sifive_gpio_set_ie(chip, offset); + return 0; +} + +static void sifive_gpio_irq_enable(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct sifive_gpio *chip = gpiochip_get_data(gc); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + int offset = hwirq % SIFIVE_GPIO_MAX; + u32 bit = BIT(offset); + unsigned long flags; + + gpiochip_enable_irq(gc, hwirq); + irq_chip_enable_parent(d); + + /* Switch to input */ + gc->direction_input(gc, offset); + + raw_spin_lock_irqsave(&gc->bgpio_lock, flags); + /* Clear any sticky pending interrupts */ + regmap_write(chip->regs, SIFIVE_GPIO_RISE_IP, bit); + regmap_write(chip->regs, SIFIVE_GPIO_FALL_IP, bit); + regmap_write(chip->regs, SIFIVE_GPIO_HIGH_IP, bit); + regmap_write(chip->regs, SIFIVE_GPIO_LOW_IP, bit); + raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags); + + /* Enable interrupts */ + assign_bit(offset, &chip->irq_state, 1); + sifive_gpio_set_ie(chip, offset); +} + +static void sifive_gpio_irq_disable(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct sifive_gpio *chip = gpiochip_get_data(gc); + irq_hw_number_t hwirq = irqd_to_hwirq(d); + int offset = hwirq % SIFIVE_GPIO_MAX; + + assign_bit(offset, &chip->irq_state, 0); + sifive_gpio_set_ie(chip, offset); + irq_chip_disable_parent(d); + gpiochip_disable_irq(gc, hwirq); +} + +static void sifive_gpio_irq_eoi(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct sifive_gpio *chip = gpiochip_get_data(gc); + int offset = irqd_to_hwirq(d) % SIFIVE_GPIO_MAX; + u32 bit = BIT(offset); + unsigned long flags; + + raw_spin_lock_irqsave(&gc->bgpio_lock, flags); + /* Clear all pending interrupts */ + regmap_write(chip->regs, SIFIVE_GPIO_RISE_IP, bit); + regmap_write(chip->regs, SIFIVE_GPIO_FALL_IP, bit); + regmap_write(chip->regs, SIFIVE_GPIO_HIGH_IP, bit); + regmap_write(chip->regs, SIFIVE_GPIO_LOW_IP, bit); + raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags); + + irq_chip_eoi_parent(d); +} + +static int sifive_gpio_irq_set_affinity(struct irq_data *data, + const struct cpumask *dest, + bool force) +{ + if (data->parent_data) + return irq_chip_set_affinity_parent(data, dest, force); + + return -EINVAL; +} + +static const struct irq_chip sifive_gpio_irqchip = { + .name = "sifive-gpio", + .irq_set_type = sifive_gpio_irq_set_type, + .irq_mask = irq_chip_mask_parent, + .irq_unmask = irq_chip_unmask_parent, + .irq_enable = sifive_gpio_irq_enable, + .irq_disable = sifive_gpio_irq_disable, + .irq_eoi = sifive_gpio_irq_eoi, + .irq_set_affinity = sifive_gpio_irq_set_affinity, + .irq_set_wake = irq_chip_set_wake_parent, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + +static int sifive_gpio_child_to_parent_hwirq(struct gpio_chip *gc, + unsigned int child, + unsigned int child_type, + unsigned int *parent, + unsigned int *parent_type) +{ + struct sifive_gpio *chip = gpiochip_get_data(gc); + struct irq_data *d = irq_get_irq_data(chip->irq_number[child]); + + *parent_type = IRQ_TYPE_NONE; + *parent = irqd_to_hwirq(d); + + return 0; +} + +static const struct regmap_config sifive_gpio_regmap_config = { + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .fast_io = true, + .disable_locking = true, +}; + +static int sifive_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct irq_domain *parent; + struct gpio_irq_chip *girq; + struct sifive_gpio *chip; + int ret, ngpio; + + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(chip->base)) { + dev_err(dev, "failed to allocate device memory\n"); + return PTR_ERR(chip->base); + } + + chip->regs = devm_regmap_init_mmio(dev, chip->base, + &sifive_gpio_regmap_config); + if (IS_ERR(chip->regs)) + return PTR_ERR(chip->regs); + + for (ngpio = 0; ngpio < SIFIVE_GPIO_MAX; ngpio++) { + ret = platform_get_irq_optional(pdev, ngpio); + if (ret < 0) + break; + chip->irq_number[ngpio] = ret; + } + if (!ngpio) { + dev_err(dev, "no IRQ found\n"); + return -ENODEV; + } + + /* + * The check above ensures at least one parent IRQ is valid. + * Assume all parent IRQs belong to the same domain. + */ + parent = irq_get_irq_data(chip->irq_number[0])->domain; + + ret = bgpio_init(&chip->gc, dev, 4, + chip->base + SIFIVE_GPIO_INPUT_VAL, + chip->base + SIFIVE_GPIO_OUTPUT_VAL, + NULL, + chip->base + SIFIVE_GPIO_OUTPUT_EN, + chip->base + SIFIVE_GPIO_INPUT_EN, + BGPIOF_READ_OUTPUT_REG_SET); + if (ret) { + dev_err(dev, "unable to init generic GPIO\n"); + return ret; + } + + /* Disable all GPIO interrupts before enabling parent interrupts */ + regmap_write(chip->regs, SIFIVE_GPIO_RISE_IE, 0); + regmap_write(chip->regs, SIFIVE_GPIO_FALL_IE, 0); + regmap_write(chip->regs, SIFIVE_GPIO_HIGH_IE, 0); + regmap_write(chip->regs, SIFIVE_GPIO_LOW_IE, 0); + chip->irq_state = 0; + + chip->gc.base = -1; + chip->gc.ngpio = ngpio; + chip->gc.label = dev_name(dev); + chip->gc.parent = dev; + chip->gc.owner = THIS_MODULE; + girq = &chip->gc.irq; + gpio_irq_chip_set_chip(girq, &sifive_gpio_irqchip); + girq->fwnode = dev_fwnode(dev); + girq->parent_domain = parent; + girq->child_to_parent_hwirq = sifive_gpio_child_to_parent_hwirq; + girq->handler = handle_bad_irq; + girq->default_type = IRQ_TYPE_NONE; + + platform_set_drvdata(pdev, chip); + return gpiochip_add_data(&chip->gc, chip); +} + +static const struct of_device_id sifive_gpio_match[] = { + { .compatible = "sifive,gpio0" }, + { .compatible = "sifive,fu540-c000-gpio" }, + { }, +}; + +static struct platform_driver sifive_gpio_driver = { + .probe = sifive_gpio_probe, + .driver = { + .name = "sifive_gpio", + .of_match_table = sifive_gpio_match, + }, +}; +module_platform_driver(sifive_gpio_driver) + +MODULE_AUTHOR("Yash Shah <yash.shah@sifive.com>"); +MODULE_DESCRIPTION("SiFive GPIO driver"); +MODULE_LICENSE("GPL"); |