diff options
Diffstat (limited to 'drivers/gpio/gpio-pci-idio-16.c')
| -rw-r--r-- | drivers/gpio/gpio-pci-idio-16.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c new file mode 100644 index 000000000..71a13a394 --- /dev/null +++ b/drivers/gpio/gpio-pci-idio-16.c @@ -0,0 +1,381 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * GPIO driver for the ACCES PCI-IDIO-16 + * Copyright (C) 2017 William Breathitt Gray + */ +#include <linux/bitmap.h> +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/gpio/driver.h> +#include <linux/interrupt.h> +#include <linux/irqdesc.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +/** + * struct idio_16_gpio_reg - GPIO device registers structure + * @out0_7: Read: FET Drive Outputs 0-7 + * Write: FET Drive Outputs 0-7 + * @in0_7: Read: Isolated Inputs 0-7 + * Write: Clear Interrupt + * @irq_ctl: Read: Enable IRQ + * Write: Disable IRQ + * @filter_ctl: Read: Activate Input Filters 0-15 + * Write: Deactivate Input Filters 0-15 + * @out8_15: Read: FET Drive Outputs 8-15 + * Write: FET Drive Outputs 8-15 + * @in8_15: Read: Isolated Inputs 8-15 + * Write: Unused + * @irq_status: Read: Interrupt status + * Write: Unused + */ +struct idio_16_gpio_reg { + u8 out0_7; + u8 in0_7; + u8 irq_ctl; + u8 filter_ctl; + u8 out8_15; + u8 in8_15; + u8 irq_status; +}; + +/** + * struct idio_16_gpio - GPIO device private data structure + * @chip: instance of the gpio_chip + * @lock: synchronization lock to prevent I/O race conditions + * @reg: I/O address offset for the GPIO device registers + * @irq_mask: I/O bits affected by interrupts + */ +struct idio_16_gpio { + struct gpio_chip chip; + raw_spinlock_t lock; + struct idio_16_gpio_reg __iomem *reg; + unsigned long irq_mask; +}; + +static int idio_16_gpio_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + if (offset > 15) + return GPIO_LINE_DIRECTION_IN; + + return GPIO_LINE_DIRECTION_OUT; +} + +static int idio_16_gpio_direction_input(struct gpio_chip *chip, + unsigned int offset) +{ + return 0; +} + +static int idio_16_gpio_direction_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + chip->set(chip, offset, value); + return 0; +} + +static int idio_16_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); + unsigned long mask = BIT(offset); + + if (offset < 8) + return !!(ioread8(&idio16gpio->reg->out0_7) & mask); + + if (offset < 16) + return !!(ioread8(&idio16gpio->reg->out8_15) & (mask >> 8)); + + if (offset < 24) + return !!(ioread8(&idio16gpio->reg->in0_7) & (mask >> 16)); + + return !!(ioread8(&idio16gpio->reg->in8_15) & (mask >> 24)); +} + +static int idio_16_gpio_get_multiple(struct gpio_chip *chip, + unsigned long *mask, unsigned long *bits) +{ + struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); + unsigned long offset; + unsigned long gpio_mask; + void __iomem *ports[] = { + &idio16gpio->reg->out0_7, &idio16gpio->reg->out8_15, + &idio16gpio->reg->in0_7, &idio16gpio->reg->in8_15, + }; + void __iomem *port_addr; + unsigned long port_state; + + /* clear bits array to a clean slate */ + bitmap_zero(bits, chip->ngpio); + + for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) { + port_addr = ports[offset / 8]; + port_state = ioread8(port_addr) & gpio_mask; + + bitmap_set_value8(bits, port_state, offset); + } + + return 0; +} + +static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); + unsigned int mask = BIT(offset); + void __iomem *base; + unsigned long flags; + unsigned int out_state; + + if (offset > 15) + return; + + if (offset > 7) { + mask >>= 8; + base = &idio16gpio->reg->out8_15; + } else + base = &idio16gpio->reg->out0_7; + + raw_spin_lock_irqsave(&idio16gpio->lock, flags); + + if (value) + out_state = ioread8(base) | mask; + else + out_state = ioread8(base) & ~mask; + + iowrite8(out_state, base); + + raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); +} + +static void idio_16_gpio_set_multiple(struct gpio_chip *chip, + unsigned long *mask, unsigned long *bits) +{ + struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); + unsigned long offset; + unsigned long gpio_mask; + void __iomem *ports[] = { + &idio16gpio->reg->out0_7, &idio16gpio->reg->out8_15, + }; + size_t index; + void __iomem *port_addr; + unsigned long bitmask; + unsigned long flags; + unsigned long out_state; + + for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) { + index = offset / 8; + port_addr = ports[index]; + + bitmask = bitmap_get_value8(bits, offset) & gpio_mask; + + raw_spin_lock_irqsave(&idio16gpio->lock, flags); + + out_state = ioread8(port_addr) & ~gpio_mask; + out_state |= bitmask; + iowrite8(out_state, port_addr); + + raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); + } +} + +static void idio_16_irq_ack(struct irq_data *data) +{ +} + +static void idio_16_irq_mask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); + const unsigned long mask = BIT(irqd_to_hwirq(data)); + unsigned long flags; + + idio16gpio->irq_mask &= ~mask; + + if (!idio16gpio->irq_mask) { + raw_spin_lock_irqsave(&idio16gpio->lock, flags); + + iowrite8(0, &idio16gpio->reg->irq_ctl); + + raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); + } +} + +static void idio_16_irq_unmask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); + const unsigned long mask = BIT(irqd_to_hwirq(data)); + const unsigned long prev_irq_mask = idio16gpio->irq_mask; + unsigned long flags; + + idio16gpio->irq_mask |= mask; + + if (!prev_irq_mask) { + raw_spin_lock_irqsave(&idio16gpio->lock, flags); + + ioread8(&idio16gpio->reg->irq_ctl); + + raw_spin_unlock_irqrestore(&idio16gpio->lock, flags); + } +} + +static int idio_16_irq_set_type(struct irq_data *data, unsigned int flow_type) +{ + /* The only valid irq types are none and both-edges */ + if (flow_type != IRQ_TYPE_NONE && + (flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH) + return -EINVAL; + + return 0; +} + +static struct irq_chip idio_16_irqchip = { + .name = "pci-idio-16", + .irq_ack = idio_16_irq_ack, + .irq_mask = idio_16_irq_mask, + .irq_unmask = idio_16_irq_unmask, + .irq_set_type = idio_16_irq_set_type +}; + +static irqreturn_t idio_16_irq_handler(int irq, void *dev_id) +{ + struct idio_16_gpio *const idio16gpio = dev_id; + unsigned int irq_status; + struct gpio_chip *const chip = &idio16gpio->chip; + int gpio; + + raw_spin_lock(&idio16gpio->lock); + + irq_status = ioread8(&idio16gpio->reg->irq_status); + + raw_spin_unlock(&idio16gpio->lock); + + /* Make sure our device generated IRQ */ + if (!(irq_status & 0x3) || !(irq_status & 0x4)) + return IRQ_NONE; + + for_each_set_bit(gpio, &idio16gpio->irq_mask, chip->ngpio) + generic_handle_domain_irq(chip->irq.domain, gpio); + + raw_spin_lock(&idio16gpio->lock); + + /* Clear interrupt */ + iowrite8(0, &idio16gpio->reg->in0_7); + + raw_spin_unlock(&idio16gpio->lock); + + return IRQ_HANDLED; +} + +#define IDIO_16_NGPIO 32 +static const char *idio_16_names[IDIO_16_NGPIO] = { + "OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7", + "OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15", + "IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7", + "IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15" +}; + +static int idio_16_irq_init_hw(struct gpio_chip *gc) +{ + struct idio_16_gpio *const idio16gpio = gpiochip_get_data(gc); + + /* Disable IRQ by default and clear any pending interrupt */ + iowrite8(0, &idio16gpio->reg->irq_ctl); + iowrite8(0, &idio16gpio->reg->in0_7); + + return 0; +} + +static int idio_16_probe(struct pci_dev *pdev, const struct pci_device_id *id) +{ + struct device *const dev = &pdev->dev; + struct idio_16_gpio *idio16gpio; + int err; + const size_t pci_bar_index = 2; + const char *const name = pci_name(pdev); + struct gpio_irq_chip *girq; + + idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL); + if (!idio16gpio) + return -ENOMEM; + + err = pcim_enable_device(pdev); + if (err) { + dev_err(dev, "Failed to enable PCI device (%d)\n", err); + return err; + } + + err = pcim_iomap_regions(pdev, BIT(pci_bar_index), name); + if (err) { + dev_err(dev, "Unable to map PCI I/O addresses (%d)\n", err); + return err; + } + + idio16gpio->reg = pcim_iomap_table(pdev)[pci_bar_index]; + + /* Deactivate input filters */ + iowrite8(0, &idio16gpio->reg->filter_ctl); + + idio16gpio->chip.label = name; + idio16gpio->chip.parent = dev; + idio16gpio->chip.owner = THIS_MODULE; + idio16gpio->chip.base = -1; + idio16gpio->chip.ngpio = IDIO_16_NGPIO; + idio16gpio->chip.names = idio_16_names; + idio16gpio->chip.get_direction = idio_16_gpio_get_direction; + idio16gpio->chip.direction_input = idio_16_gpio_direction_input; + idio16gpio->chip.direction_output = idio_16_gpio_direction_output; + idio16gpio->chip.get = idio_16_gpio_get; + idio16gpio->chip.get_multiple = idio_16_gpio_get_multiple; + idio16gpio->chip.set = idio_16_gpio_set; + idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple; + + girq = &idio16gpio->chip.irq; + girq->chip = &idio_16_irqchip; + /* This will let us handle the parent IRQ in the driver */ + girq->parent_handler = NULL; + girq->num_parents = 0; + girq->parents = NULL; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_edge_irq; + girq->init_hw = idio_16_irq_init_hw; + + raw_spin_lock_init(&idio16gpio->lock); + + err = devm_gpiochip_add_data(dev, &idio16gpio->chip, idio16gpio); + if (err) { + dev_err(dev, "GPIO registering failed (%d)\n", err); + return err; + } + + err = devm_request_irq(dev, pdev->irq, idio_16_irq_handler, IRQF_SHARED, + name, idio16gpio); + if (err) { + dev_err(dev, "IRQ handler registering failed (%d)\n", err); + return err; + } + + return 0; +} + +static const struct pci_device_id idio_16_pci_dev_id[] = { + { PCI_DEVICE(0x494F, 0x0DC8) }, { 0 } +}; +MODULE_DEVICE_TABLE(pci, idio_16_pci_dev_id); + +static struct pci_driver idio_16_driver = { + .name = "pci-idio-16", + .id_table = idio_16_pci_dev_id, + .probe = idio_16_probe +}; + +module_pci_driver(idio_16_driver); + +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); +MODULE_DESCRIPTION("ACCES PCI-IDIO-16 GPIO driver"); +MODULE_LICENSE("GPL v2"); |