| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * GPIO driver for the WinSystems WS16C48 |
| * Copyright (C) 2016 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/io.h> |
| #include <linux/ioport.h> |
| #include <linux/interrupt.h> |
| #include <linux/irqdesc.h> |
| #include <linux/isa.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/spinlock.h> |
| |
| #define WS16C48_EXTENT 16 |
| #define MAX_NUM_WS16C48 max_num_isa_dev(WS16C48_EXTENT) |
| |
| static unsigned int base[MAX_NUM_WS16C48]; |
| static unsigned int num_ws16c48; |
| module_param_hw_array(base, uint, ioport, &num_ws16c48, 0); |
| MODULE_PARM_DESC(base, "WinSystems WS16C48 base addresses"); |
| |
| static unsigned int irq[MAX_NUM_WS16C48]; |
| module_param_hw_array(irq, uint, irq, NULL, 0); |
| MODULE_PARM_DESC(irq, "WinSystems WS16C48 interrupt line numbers"); |
| |
| /** |
| * struct ws16c48_gpio - GPIO device private data structure |
| * @chip: instance of the gpio_chip |
| * @io_state: bit I/O state (whether bit is set to input or output) |
| * @out_state: output bits state |
| * @lock: synchronization lock to prevent I/O race conditions |
| * @irq_mask: I/O bits affected by interrupts |
| * @flow_mask: IRQ flow type mask for the respective I/O bits |
| * @base: base port address of the GPIO device |
| */ |
| struct ws16c48_gpio { |
| struct gpio_chip chip; |
| unsigned char io_state[6]; |
| unsigned char out_state[6]; |
| raw_spinlock_t lock; |
| unsigned long irq_mask; |
| unsigned long flow_mask; |
| void __iomem *base; |
| }; |
| |
| static int ws16c48_gpio_get_direction(struct gpio_chip *chip, unsigned offset) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned port = offset / 8; |
| const unsigned mask = BIT(offset % 8); |
| |
| if (ws16c48gpio->io_state[port] & mask) |
| return GPIO_LINE_DIRECTION_IN; |
| |
| return GPIO_LINE_DIRECTION_OUT; |
| } |
| |
| static int ws16c48_gpio_direction_input(struct gpio_chip *chip, unsigned offset) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned port = offset / 8; |
| const unsigned mask = BIT(offset % 8); |
| unsigned long flags; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| ws16c48gpio->io_state[port] |= mask; |
| ws16c48gpio->out_state[port] &= ~mask; |
| iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->base + port); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| |
| return 0; |
| } |
| |
| static int ws16c48_gpio_direction_output(struct gpio_chip *chip, |
| unsigned offset, int value) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned port = offset / 8; |
| const unsigned mask = BIT(offset % 8); |
| unsigned long flags; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| ws16c48gpio->io_state[port] &= ~mask; |
| if (value) |
| ws16c48gpio->out_state[port] |= mask; |
| else |
| ws16c48gpio->out_state[port] &= ~mask; |
| iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->base + port); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| |
| return 0; |
| } |
| |
| static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned port = offset / 8; |
| const unsigned mask = BIT(offset % 8); |
| unsigned long flags; |
| unsigned port_state; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| /* ensure that GPIO is set for input */ |
| if (!(ws16c48gpio->io_state[port] & mask)) { |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| return -EINVAL; |
| } |
| |
| port_state = ioread8(ws16c48gpio->base + port); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| |
| return !!(port_state & mask); |
| } |
| |
| static int ws16c48_gpio_get_multiple(struct gpio_chip *chip, |
| unsigned long *mask, unsigned long *bits) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| unsigned long offset; |
| unsigned long gpio_mask; |
| 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, chip->ngpio) { |
| port_addr = ws16c48gpio->base + offset / 8; |
| port_state = ioread8(port_addr) & gpio_mask; |
| |
| bitmap_set_value8(bits, port_state, offset); |
| } |
| |
| return 0; |
| } |
| |
| static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned port = offset / 8; |
| const unsigned mask = BIT(offset % 8); |
| unsigned long flags; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| /* ensure that GPIO is set for output */ |
| if (ws16c48gpio->io_state[port] & mask) { |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| return; |
| } |
| |
| if (value) |
| ws16c48gpio->out_state[port] |= mask; |
| else |
| ws16c48gpio->out_state[port] &= ~mask; |
| iowrite8(ws16c48gpio->out_state[port], ws16c48gpio->base + port); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| } |
| |
| static void ws16c48_gpio_set_multiple(struct gpio_chip *chip, |
| unsigned long *mask, unsigned long *bits) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| unsigned long offset; |
| unsigned long gpio_mask; |
| size_t index; |
| void __iomem *port_addr; |
| unsigned long bitmask; |
| unsigned long flags; |
| |
| for_each_set_clump8(offset, gpio_mask, mask, chip->ngpio) { |
| index = offset / 8; |
| port_addr = ws16c48gpio->base + index; |
| |
| /* mask out GPIO configured for input */ |
| gpio_mask &= ~ws16c48gpio->io_state[index]; |
| bitmask = bitmap_get_value8(bits, offset) & gpio_mask; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| /* update output state data and set device gpio register */ |
| ws16c48gpio->out_state[index] &= ~gpio_mask; |
| ws16c48gpio->out_state[index] |= bitmask; |
| iowrite8(ws16c48gpio->out_state[index], port_addr); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| } |
| } |
| |
| static void ws16c48_irq_ack(struct irq_data *data) |
| { |
| struct gpio_chip *chip = irq_data_get_irq_chip_data(data); |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned long offset = irqd_to_hwirq(data); |
| const unsigned port = offset / 8; |
| const unsigned mask = BIT(offset % 8); |
| unsigned long flags; |
| unsigned port_state; |
| |
| /* only the first 3 ports support interrupts */ |
| if (port > 2) |
| return; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| port_state = ws16c48gpio->irq_mask >> (8*port); |
| |
| iowrite8(0x80, ws16c48gpio->base + 7); |
| iowrite8(port_state & ~mask, ws16c48gpio->base + 8 + port); |
| iowrite8(port_state | mask, ws16c48gpio->base + 8 + port); |
| iowrite8(0xC0, ws16c48gpio->base + 7); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| } |
| |
| static void ws16c48_irq_mask(struct irq_data *data) |
| { |
| struct gpio_chip *chip = irq_data_get_irq_chip_data(data); |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned long offset = irqd_to_hwirq(data); |
| const unsigned long mask = BIT(offset); |
| const unsigned port = offset / 8; |
| unsigned long flags; |
| |
| /* only the first 3 ports support interrupts */ |
| if (port > 2) |
| return; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| ws16c48gpio->irq_mask &= ~mask; |
| |
| iowrite8(0x80, ws16c48gpio->base + 7); |
| iowrite8(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port); |
| iowrite8(0xC0, ws16c48gpio->base + 7); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| } |
| |
| static void ws16c48_irq_unmask(struct irq_data *data) |
| { |
| struct gpio_chip *chip = irq_data_get_irq_chip_data(data); |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned long offset = irqd_to_hwirq(data); |
| const unsigned long mask = BIT(offset); |
| const unsigned port = offset / 8; |
| unsigned long flags; |
| |
| /* only the first 3 ports support interrupts */ |
| if (port > 2) |
| return; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| ws16c48gpio->irq_mask |= mask; |
| |
| iowrite8(0x80, ws16c48gpio->base + 7); |
| iowrite8(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port); |
| iowrite8(0xC0, ws16c48gpio->base + 7); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| } |
| |
| static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type) |
| { |
| struct gpio_chip *chip = irq_data_get_irq_chip_data(data); |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); |
| const unsigned long offset = irqd_to_hwirq(data); |
| const unsigned long mask = BIT(offset); |
| const unsigned port = offset / 8; |
| unsigned long flags; |
| |
| /* only the first 3 ports support interrupts */ |
| if (port > 2) |
| return -EINVAL; |
| |
| raw_spin_lock_irqsave(&ws16c48gpio->lock, flags); |
| |
| switch (flow_type) { |
| case IRQ_TYPE_NONE: |
| break; |
| case IRQ_TYPE_EDGE_RISING: |
| ws16c48gpio->flow_mask |= mask; |
| break; |
| case IRQ_TYPE_EDGE_FALLING: |
| ws16c48gpio->flow_mask &= ~mask; |
| break; |
| default: |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| return -EINVAL; |
| } |
| |
| iowrite8(0x40, ws16c48gpio->base + 7); |
| iowrite8(ws16c48gpio->flow_mask >> (8*port), ws16c48gpio->base + 8 + port); |
| iowrite8(0xC0, ws16c48gpio->base + 7); |
| |
| raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags); |
| |
| return 0; |
| } |
| |
| static struct irq_chip ws16c48_irqchip = { |
| .name = "ws16c48", |
| .irq_ack = ws16c48_irq_ack, |
| .irq_mask = ws16c48_irq_mask, |
| .irq_unmask = ws16c48_irq_unmask, |
| .irq_set_type = ws16c48_irq_set_type |
| }; |
| |
| static irqreturn_t ws16c48_irq_handler(int irq, void *dev_id) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = dev_id; |
| struct gpio_chip *const chip = &ws16c48gpio->chip; |
| unsigned long int_pending; |
| unsigned long port; |
| unsigned long int_id; |
| unsigned long gpio; |
| |
| int_pending = ioread8(ws16c48gpio->base + 6) & 0x7; |
| if (!int_pending) |
| return IRQ_NONE; |
| |
| /* loop until all pending interrupts are handled */ |
| do { |
| for_each_set_bit(port, &int_pending, 3) { |
| int_id = ioread8(ws16c48gpio->base + 8 + port); |
| for_each_set_bit(gpio, &int_id, 8) |
| generic_handle_domain_irq(chip->irq.domain, |
| gpio + 8*port); |
| } |
| |
| int_pending = ioread8(ws16c48gpio->base + 6) & 0x7; |
| } while (int_pending); |
| |
| return IRQ_HANDLED; |
| } |
| |
| #define WS16C48_NGPIO 48 |
| static const char *ws16c48_names[WS16C48_NGPIO] = { |
| "Port 0 Bit 0", "Port 0 Bit 1", "Port 0 Bit 2", "Port 0 Bit 3", |
| "Port 0 Bit 4", "Port 0 Bit 5", "Port 0 Bit 6", "Port 0 Bit 7", |
| "Port 1 Bit 0", "Port 1 Bit 1", "Port 1 Bit 2", "Port 1 Bit 3", |
| "Port 1 Bit 4", "Port 1 Bit 5", "Port 1 Bit 6", "Port 1 Bit 7", |
| "Port 2 Bit 0", "Port 2 Bit 1", "Port 2 Bit 2", "Port 2 Bit 3", |
| "Port 2 Bit 4", "Port 2 Bit 5", "Port 2 Bit 6", "Port 2 Bit 7", |
| "Port 3 Bit 0", "Port 3 Bit 1", "Port 3 Bit 2", "Port 3 Bit 3", |
| "Port 3 Bit 4", "Port 3 Bit 5", "Port 3 Bit 6", "Port 3 Bit 7", |
| "Port 4 Bit 0", "Port 4 Bit 1", "Port 4 Bit 2", "Port 4 Bit 3", |
| "Port 4 Bit 4", "Port 4 Bit 5", "Port 4 Bit 6", "Port 4 Bit 7", |
| "Port 5 Bit 0", "Port 5 Bit 1", "Port 5 Bit 2", "Port 5 Bit 3", |
| "Port 5 Bit 4", "Port 5 Bit 5", "Port 5 Bit 6", "Port 5 Bit 7" |
| }; |
| |
| static int ws16c48_irq_init_hw(struct gpio_chip *gc) |
| { |
| struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(gc); |
| |
| /* Disable IRQ by default */ |
| iowrite8(0x80, ws16c48gpio->base + 7); |
| iowrite8(0, ws16c48gpio->base + 8); |
| iowrite8(0, ws16c48gpio->base + 9); |
| iowrite8(0, ws16c48gpio->base + 10); |
| iowrite8(0xC0, ws16c48gpio->base + 7); |
| |
| return 0; |
| } |
| |
| static int ws16c48_probe(struct device *dev, unsigned int id) |
| { |
| struct ws16c48_gpio *ws16c48gpio; |
| const char *const name = dev_name(dev); |
| struct gpio_irq_chip *girq; |
| int err; |
| |
| ws16c48gpio = devm_kzalloc(dev, sizeof(*ws16c48gpio), GFP_KERNEL); |
| if (!ws16c48gpio) |
| return -ENOMEM; |
| |
| if (!devm_request_region(dev, base[id], WS16C48_EXTENT, name)) { |
| dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", |
| base[id], base[id] + WS16C48_EXTENT); |
| return -EBUSY; |
| } |
| |
| ws16c48gpio->base = devm_ioport_map(dev, base[id], WS16C48_EXTENT); |
| if (!ws16c48gpio->base) |
| return -ENOMEM; |
| |
| ws16c48gpio->chip.label = name; |
| ws16c48gpio->chip.parent = dev; |
| ws16c48gpio->chip.owner = THIS_MODULE; |
| ws16c48gpio->chip.base = -1; |
| ws16c48gpio->chip.ngpio = WS16C48_NGPIO; |
| ws16c48gpio->chip.names = ws16c48_names; |
| ws16c48gpio->chip.get_direction = ws16c48_gpio_get_direction; |
| ws16c48gpio->chip.direction_input = ws16c48_gpio_direction_input; |
| ws16c48gpio->chip.direction_output = ws16c48_gpio_direction_output; |
| ws16c48gpio->chip.get = ws16c48_gpio_get; |
| ws16c48gpio->chip.get_multiple = ws16c48_gpio_get_multiple; |
| ws16c48gpio->chip.set = ws16c48_gpio_set; |
| ws16c48gpio->chip.set_multiple = ws16c48_gpio_set_multiple; |
| |
| girq = &ws16c48gpio->chip.irq; |
| girq->chip = &ws16c48_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 = ws16c48_irq_init_hw; |
| |
| raw_spin_lock_init(&ws16c48gpio->lock); |
| |
| err = devm_gpiochip_add_data(dev, &ws16c48gpio->chip, ws16c48gpio); |
| if (err) { |
| dev_err(dev, "GPIO registering failed (%d)\n", err); |
| return err; |
| } |
| |
| err = devm_request_irq(dev, irq[id], ws16c48_irq_handler, IRQF_SHARED, |
| name, ws16c48gpio); |
| if (err) { |
| dev_err(dev, "IRQ handler registering failed (%d)\n", err); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static struct isa_driver ws16c48_driver = { |
| .probe = ws16c48_probe, |
| .driver = { |
| .name = "ws16c48" |
| }, |
| }; |
| |
| module_isa_driver(ws16c48_driver, num_ws16c48); |
| |
| MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); |
| MODULE_DESCRIPTION("WinSystems WS16C48 GPIO driver"); |
| MODULE_LICENSE("GPL v2"); |