diff options
Diffstat (limited to 'drivers/gpio/gpio-104-idi-48.c')
| -rw-r--r-- | drivers/gpio/gpio-104-idi-48.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c new file mode 100644 index 000000000..2c9738adb --- /dev/null +++ b/drivers/gpio/gpio-104-idi-48.c @@ -0,0 +1,348 @@ +/* + * GPIO driver for the ACCES 104-IDI-48 family + * Copyright (C) 2015 William Breathitt Gray + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * This driver supports the following ACCES devices: 104-IDI-48A, + * 104-IDI-48AC, 104-IDI-48B, and 104-IDI-48BC. + */ +#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 IDI_48_EXTENT 8 +#define MAX_NUM_IDI_48 max_num_isa_dev(IDI_48_EXTENT) + +static unsigned int base[MAX_NUM_IDI_48]; +static unsigned int num_idi_48; +module_param_hw_array(base, uint, ioport, &num_idi_48, 0); +MODULE_PARM_DESC(base, "ACCES 104-IDI-48 base addresses"); + +static unsigned int irq[MAX_NUM_IDI_48]; +module_param_hw_array(irq, uint, irq, NULL, 0); +MODULE_PARM_DESC(irq, "ACCES 104-IDI-48 interrupt line numbers"); + +/** + * struct idi_48_gpio - GPIO device private data structure + * @chip: instance of the gpio_chip + * @lock: synchronization lock to prevent I/O race conditions + * @ack_lock: synchronization lock to prevent IRQ handler race conditions + * @irq_mask: input bits affected by interrupts + * @base: base port address of the GPIO device + * @cos_enb: Change-Of-State IRQ enable boundaries mask + */ +struct idi_48_gpio { + struct gpio_chip chip; + raw_spinlock_t lock; + spinlock_t ack_lock; + unsigned char irq_mask[6]; + unsigned base; + unsigned char cos_enb; +}; + +static int idi_48_gpio_get_direction(struct gpio_chip *chip, unsigned offset) +{ + return 1; +} + +static int idi_48_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + return 0; +} + +static int idi_48_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip); + unsigned i; + const unsigned register_offset[6] = { 0, 1, 2, 4, 5, 6 }; + unsigned base_offset; + unsigned mask; + + for (i = 0; i < 48; i += 8) + if (offset < i + 8) { + base_offset = register_offset[i / 8]; + mask = BIT(offset - i); + + return !!(inb(idi48gpio->base + base_offset) & mask); + } + + /* The following line should never execute since offset < 48 */ + return 0; +} + +static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask, + unsigned long *bits) +{ + struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip); + size_t i; + static const size_t ports[] = { 0, 1, 2, 4, 5, 6 }; + const unsigned int gpio_reg_size = 8; + unsigned int bits_offset; + size_t word_index; + unsigned int word_offset; + unsigned long word_mask; + const unsigned long port_mask = GENMASK(gpio_reg_size - 1, 0); + unsigned long port_state; + + /* clear bits array to a clean slate */ + bitmap_zero(bits, chip->ngpio); + + /* get bits are evaluated a gpio port register at a time */ + for (i = 0; i < ARRAY_SIZE(ports); i++) { + /* gpio offset in bits array */ + bits_offset = i * gpio_reg_size; + + /* word index for bits array */ + word_index = BIT_WORD(bits_offset); + + /* gpio offset within current word of bits array */ + word_offset = bits_offset % BITS_PER_LONG; + + /* mask of get bits for current gpio within current word */ + word_mask = mask[word_index] & (port_mask << word_offset); + if (!word_mask) { + /* no get bits in this port so skip to next one */ + continue; + } + + /* read bits from current gpio port */ + port_state = inb(idi48gpio->base + ports[i]); + + /* store acquired bits at respective bits array offset */ + bits[word_index] |= port_state << word_offset; + } + + return 0; +} + +static void idi_48_irq_ack(struct irq_data *data) +{ +} + +static void idi_48_irq_mask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip); + const unsigned offset = irqd_to_hwirq(data); + unsigned i; + unsigned mask; + unsigned boundary; + unsigned long flags; + + for (i = 0; i < 48; i += 8) + if (offset < i + 8) { + mask = BIT(offset - i); + boundary = i / 8; + + idi48gpio->irq_mask[boundary] &= ~mask; + + if (!idi48gpio->irq_mask[boundary]) { + idi48gpio->cos_enb &= ~BIT(boundary); + + raw_spin_lock_irqsave(&idi48gpio->lock, flags); + + outb(idi48gpio->cos_enb, idi48gpio->base + 7); + + raw_spin_unlock_irqrestore(&idi48gpio->lock, + flags); + } + + return; + } +} + +static void idi_48_irq_unmask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip); + const unsigned offset = irqd_to_hwirq(data); + unsigned i; + unsigned mask; + unsigned boundary; + unsigned prev_irq_mask; + unsigned long flags; + + for (i = 0; i < 48; i += 8) + if (offset < i + 8) { + mask = BIT(offset - i); + boundary = i / 8; + prev_irq_mask = idi48gpio->irq_mask[boundary]; + + idi48gpio->irq_mask[boundary] |= mask; + + if (!prev_irq_mask) { + idi48gpio->cos_enb |= BIT(boundary); + + raw_spin_lock_irqsave(&idi48gpio->lock, flags); + + outb(idi48gpio->cos_enb, idi48gpio->base + 7); + + raw_spin_unlock_irqrestore(&idi48gpio->lock, + flags); + } + + return; + } +} + +static int idi_48_irq_set_type(struct irq_data *data, unsigned 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 idi_48_irqchip = { + .name = "104-idi-48", + .irq_ack = idi_48_irq_ack, + .irq_mask = idi_48_irq_mask, + .irq_unmask = idi_48_irq_unmask, + .irq_set_type = idi_48_irq_set_type +}; + +static irqreturn_t idi_48_irq_handler(int irq, void *dev_id) +{ + struct idi_48_gpio *const idi48gpio = dev_id; + unsigned long cos_status; + unsigned long boundary; + unsigned long irq_mask; + unsigned long bit_num; + unsigned long gpio; + struct gpio_chip *const chip = &idi48gpio->chip; + + spin_lock(&idi48gpio->ack_lock); + + raw_spin_lock(&idi48gpio->lock); + + cos_status = inb(idi48gpio->base + 7); + + raw_spin_unlock(&idi48gpio->lock); + + /* IRQ Status (bit 6) is active low (0 = IRQ generated by device) */ + if (cos_status & BIT(6)) { + spin_unlock(&idi48gpio->ack_lock); + return IRQ_NONE; + } + + /* Bit 0-5 indicate which Change-Of-State boundary triggered the IRQ */ + cos_status &= 0x3F; + + for_each_set_bit(boundary, &cos_status, 6) { + irq_mask = idi48gpio->irq_mask[boundary]; + + for_each_set_bit(bit_num, &irq_mask, 8) { + gpio = bit_num + boundary * 8; + + generic_handle_irq(irq_find_mapping(chip->irq.domain, + gpio)); + } + } + + spin_unlock(&idi48gpio->ack_lock); + + return IRQ_HANDLED; +} + +#define IDI48_NGPIO 48 +static const char *idi48_names[IDI48_NGPIO] = { + "Bit 0 A", "Bit 1 A", "Bit 2 A", "Bit 3 A", "Bit 4 A", "Bit 5 A", + "Bit 6 A", "Bit 7 A", "Bit 8 A", "Bit 9 A", "Bit 10 A", "Bit 11 A", + "Bit 12 A", "Bit 13 A", "Bit 14 A", "Bit 15 A", "Bit 16 A", "Bit 17 A", + "Bit 18 A", "Bit 19 A", "Bit 20 A", "Bit 21 A", "Bit 22 A", "Bit 23 A", + "Bit 0 B", "Bit 1 B", "Bit 2 B", "Bit 3 B", "Bit 4 B", "Bit 5 B", + "Bit 6 B", "Bit 7 B", "Bit 8 B", "Bit 9 B", "Bit 10 B", "Bit 11 B", + "Bit 12 B", "Bit 13 B", "Bit 14 B", "Bit 15 B", "Bit 16 B", "Bit 17 B", + "Bit 18 B", "Bit 19 B", "Bit 20 B", "Bit 21 B", "Bit 22 B", "Bit 23 B" +}; + +static int idi_48_probe(struct device *dev, unsigned int id) +{ + struct idi_48_gpio *idi48gpio; + const char *const name = dev_name(dev); + int err; + + idi48gpio = devm_kzalloc(dev, sizeof(*idi48gpio), GFP_KERNEL); + if (!idi48gpio) + return -ENOMEM; + + if (!devm_request_region(dev, base[id], IDI_48_EXTENT, name)) { + dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", + base[id], base[id] + IDI_48_EXTENT); + return -EBUSY; + } + + idi48gpio->chip.label = name; + idi48gpio->chip.parent = dev; + idi48gpio->chip.owner = THIS_MODULE; + idi48gpio->chip.base = -1; + idi48gpio->chip.ngpio = IDI48_NGPIO; + idi48gpio->chip.names = idi48_names; + idi48gpio->chip.get_direction = idi_48_gpio_get_direction; + idi48gpio->chip.direction_input = idi_48_gpio_direction_input; + idi48gpio->chip.get = idi_48_gpio_get; + idi48gpio->chip.get_multiple = idi_48_gpio_get_multiple; + idi48gpio->base = base[id]; + + raw_spin_lock_init(&idi48gpio->lock); + spin_lock_init(&idi48gpio->ack_lock); + + err = devm_gpiochip_add_data(dev, &idi48gpio->chip, idi48gpio); + if (err) { + dev_err(dev, "GPIO registering failed (%d)\n", err); + return err; + } + + /* Disable IRQ by default */ + outb(0, base[id] + 7); + inb(base[id] + 7); + + err = gpiochip_irqchip_add(&idi48gpio->chip, &idi_48_irqchip, 0, + handle_edge_irq, IRQ_TYPE_NONE); + if (err) { + dev_err(dev, "Could not add irqchip (%d)\n", err); + return err; + } + + err = devm_request_irq(dev, irq[id], idi_48_irq_handler, IRQF_SHARED, + name, idi48gpio); + if (err) { + dev_err(dev, "IRQ handler registering failed (%d)\n", err); + return err; + } + + return 0; +} + +static struct isa_driver idi_48_driver = { + .probe = idi_48_probe, + .driver = { + .name = "104-idi-48" + }, +}; +module_isa_driver(idi_48_driver, num_idi_48); + +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); +MODULE_DESCRIPTION("ACCES 104-IDI-48 GPIO driver"); +MODULE_LICENSE("GPL v2"); |