linux/drivers/gpio/gpio-pcie-idio-24.c

565 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* GPIO driver for the ACCES PCIe-IDIO-24 family
* Copyright (C) 2018 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: PCIe-IDIO-24,
* PCIe-IDI-24, PCIe-IDO-24, and PCIe-IDIO-12.
*/
#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_24_gpio_reg - GPIO device registers structure
* @out0_7: Read: FET Outputs 0-7
* Write: FET Outputs 0-7
* @out8_15: Read: FET Outputs 8-15
* Write: FET Outputs 8-15
* @out16_23: Read: FET Outputs 16-23
* Write: FET Outputs 16-23
* @ttl_out0_7: Read: TTL/CMOS Outputs 0-7
* Write: TTL/CMOS Outputs 0-7
* @in0_7: Read: Isolated Inputs 0-7
* Write: Reserved
* @in8_15: Read: Isolated Inputs 8-15
* Write: Reserved
* @in16_23: Read: Isolated Inputs 16-23
* Write: Reserved
* @ttl_in0_7: Read: TTL/CMOS Inputs 0-7
* Write: Reserved
* @cos0_7: Read: COS Status Inputs 0-7
* Write: COS Clear Inputs 0-7
* @cos8_15: Read: COS Status Inputs 8-15
* Write: COS Clear Inputs 8-15
* @cos16_23: Read: COS Status Inputs 16-23
* Write: COS Clear Inputs 16-23
* @cos_ttl0_7: Read: COS Status TTL/CMOS 0-7
* Write: COS Clear TTL/CMOS 0-7
* @ctl: Read: Control Register
* Write: Control Register
* @reserved: Read: Reserved
* Write: Reserved
* @cos_enable: Read: COS Enable
* Write: COS Enable
* @soft_reset: Read: IRQ Output Pin Status
* Write: Software Board Reset
*/
struct idio_24_gpio_reg {
u8 out0_7;
u8 out8_15;
u8 out16_23;
u8 ttl_out0_7;
u8 in0_7;
u8 in8_15;
u8 in16_23;
u8 ttl_in0_7;
u8 cos0_7;
u8 cos8_15;
u8 cos16_23;
u8 cos_ttl0_7;
u8 ctl;
u8 reserved;
u8 cos_enable;
u8 soft_reset;
};
/**
* struct idio_24_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_24_gpio {
struct gpio_chip chip;
raw_spinlock_t lock;
struct idio_24_gpio_reg __iomem *reg;
unsigned long irq_mask;
};
static int idio_24_gpio_get_direction(struct gpio_chip *chip,
unsigned int offset)
{
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
const unsigned long out_mode_mask = BIT(1);
/* FET Outputs */
if (offset < 24)
return 0;
/* Isolated Inputs */
if (offset < 48)
return 1;
/* TTL/CMOS I/O */
/* OUT MODE = 1 when TTL/CMOS Output Mode is set */
return !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask);
}
static int idio_24_gpio_direction_input(struct gpio_chip *chip,
unsigned int offset)
{
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
unsigned long flags;
unsigned int ctl_state;
const unsigned long out_mode_mask = BIT(1);
/* TTL/CMOS I/O */
if (offset > 47) {
raw_spin_lock_irqsave(&idio24gpio->lock, flags);
/* Clear TTL/CMOS Output Mode */
ctl_state = ioread8(&idio24gpio->reg->ctl) & ~out_mode_mask;
iowrite8(ctl_state, &idio24gpio->reg->ctl);
raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
}
return 0;
}
static int idio_24_gpio_direction_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
unsigned long flags;
unsigned int ctl_state;
const unsigned long out_mode_mask = BIT(1);
/* TTL/CMOS I/O */
if (offset > 47) {
raw_spin_lock_irqsave(&idio24gpio->lock, flags);
/* Set TTL/CMOS Output Mode */
ctl_state = ioread8(&idio24gpio->reg->ctl) | out_mode_mask;
iowrite8(ctl_state, &idio24gpio->reg->ctl);
raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
}
chip->set(chip, offset, value);
return 0;
}
static int idio_24_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
const unsigned long offset_mask = BIT(offset % 8);
const unsigned long out_mode_mask = BIT(1);
/* FET Outputs */
if (offset < 8)
return !!(ioread8(&idio24gpio->reg->out0_7) & offset_mask);
if (offset < 16)
return !!(ioread8(&idio24gpio->reg->out8_15) & offset_mask);
if (offset < 24)
return !!(ioread8(&idio24gpio->reg->out16_23) & offset_mask);
/* Isolated Inputs */
if (offset < 32)
return !!(ioread8(&idio24gpio->reg->in0_7) & offset_mask);
if (offset < 40)
return !!(ioread8(&idio24gpio->reg->in8_15) & offset_mask);
if (offset < 48)
return !!(ioread8(&idio24gpio->reg->in16_23) & offset_mask);
/* TTL/CMOS Outputs */
if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)
return !!(ioread8(&idio24gpio->reg->ttl_out0_7) & offset_mask);
/* TTL/CMOS Inputs */
return !!(ioread8(&idio24gpio->reg->ttl_in0_7) & offset_mask);
}
static int idio_24_gpio_get_multiple(struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
size_t i;
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;
void __iomem *ports[] = {
&idio24gpio->reg->out0_7, &idio24gpio->reg->out8_15,
&idio24gpio->reg->out16_23, &idio24gpio->reg->in0_7,
&idio24gpio->reg->in8_15, &idio24gpio->reg->in16_23,
};
const unsigned long out_mode_mask = BIT(1);
/* 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) + 1; 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 6 is TTL GPIO) */
if (i < 6)
port_state = ioread8(ports[i]);
else if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)
port_state = ioread8(&idio24gpio->reg->ttl_out0_7);
else
port_state = ioread8(&idio24gpio->reg->ttl_in0_7);
/* store acquired bits at respective bits array offset */
bits[word_index] |= port_state << word_offset;
}
return 0;
}
static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
const unsigned long out_mode_mask = BIT(1);
void __iomem *base;
const unsigned int mask = BIT(offset % 8);
unsigned long flags;
unsigned int out_state;
/* Isolated Inputs */
if (offset > 23 && offset < 48)
return;
/* TTL/CMOS Inputs */
if (offset > 47 && !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask))
return;
/* TTL/CMOS Outputs */
if (offset > 47)
base = &idio24gpio->reg->ttl_out0_7;
/* FET Outputs */
else if (offset > 15)
base = &idio24gpio->reg->out16_23;
else if (offset > 7)
base = &idio24gpio->reg->out8_15;
else
base = &idio24gpio->reg->out0_7;
raw_spin_lock_irqsave(&idio24gpio->lock, flags);
if (value)
out_state = ioread8(base) | mask;
else
out_state = ioread8(base) & ~mask;
iowrite8(out_state, base);
raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
}
static void idio_24_gpio_set_multiple(struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
size_t i;
unsigned long bits_offset;
unsigned long gpio_mask;
const unsigned int gpio_reg_size = 8;
const unsigned long port_mask = GENMASK(gpio_reg_size, 0);
unsigned long flags;
unsigned int out_state;
void __iomem *ports[] = {
&idio24gpio->reg->out0_7, &idio24gpio->reg->out8_15,
&idio24gpio->reg->out16_23
};
const unsigned long out_mode_mask = BIT(1);
const unsigned int ttl_offset = 48;
const size_t ttl_i = BIT_WORD(ttl_offset);
const unsigned int word_offset = ttl_offset % BITS_PER_LONG;
const unsigned long ttl_mask = (mask[ttl_i] >> word_offset) & port_mask;
const unsigned long ttl_bits = (bits[ttl_i] >> word_offset) & ttl_mask;
/* set bits are processed 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;
/* check if any set bits for current port */
gpio_mask = (*mask >> bits_offset) & port_mask;
if (!gpio_mask) {
/* no set bits for this port so move on to next port */
continue;
}
raw_spin_lock_irqsave(&idio24gpio->lock, flags);
/* process output lines */
out_state = ioread8(ports[i]) & ~gpio_mask;
out_state |= (*bits >> bits_offset) & gpio_mask;
iowrite8(out_state, ports[i]);
raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
}
/* check if setting TTL lines and if they are in output mode */
if (!ttl_mask || !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask))
return;
/* handle TTL output */
raw_spin_lock_irqsave(&idio24gpio->lock, flags);
/* process output lines */
out_state = ioread8(&idio24gpio->reg->ttl_out0_7) & ~ttl_mask;
out_state |= ttl_bits;
iowrite8(out_state, &idio24gpio->reg->ttl_out0_7);
raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
}
static void idio_24_irq_ack(struct irq_data *data)
{
}
static void idio_24_irq_mask(struct irq_data *data)
{
struct gpio_chip *const chip = irq_data_get_irq_chip_data(data);
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
unsigned long flags;
const unsigned long bit_offset = irqd_to_hwirq(data) - 24;
unsigned char new_irq_mask;
const unsigned long bank_offset = bit_offset/8 * 8;
unsigned char cos_enable_state;
raw_spin_lock_irqsave(&idio24gpio->lock, flags);
idio24gpio->irq_mask &= BIT(bit_offset);
new_irq_mask = idio24gpio->irq_mask >> bank_offset;
if (!new_irq_mask) {
cos_enable_state = ioread8(&idio24gpio->reg->cos_enable);
/* Disable Rising Edge detection */
cos_enable_state &= ~BIT(bank_offset);
/* Disable Falling Edge detection */
cos_enable_state &= ~BIT(bank_offset + 4);
iowrite8(cos_enable_state, &idio24gpio->reg->cos_enable);
}
raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
}
static void idio_24_irq_unmask(struct irq_data *data)
{
struct gpio_chip *const chip = irq_data_get_irq_chip_data(data);
struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
unsigned long flags;
unsigned char prev_irq_mask;
const unsigned long bit_offset = irqd_to_hwirq(data) - 24;
const unsigned long bank_offset = bit_offset/8 * 8;
unsigned char cos_enable_state;
raw_spin_lock_irqsave(&idio24gpio->lock, flags);
prev_irq_mask = idio24gpio->irq_mask >> bank_offset;
idio24gpio->irq_mask |= BIT(bit_offset);
if (!prev_irq_mask) {
cos_enable_state = ioread8(&idio24gpio->reg->cos_enable);
/* Enable Rising Edge detection */
cos_enable_state |= BIT(bank_offset);
/* Enable Falling Edge detection */
cos_enable_state |= BIT(bank_offset + 4);
iowrite8(cos_enable_state, &idio24gpio->reg->cos_enable);
}
raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
}
static int idio_24_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_24_irqchip = {
.name = "pcie-idio-24",
.irq_ack = idio_24_irq_ack,
.irq_mask = idio_24_irq_mask,
.irq_unmask = idio_24_irq_unmask,
.irq_set_type = idio_24_irq_set_type
};
static irqreturn_t idio_24_irq_handler(int irq, void *dev_id)
{
struct idio_24_gpio *const idio24gpio = dev_id;
unsigned long irq_status;
struct gpio_chip *const chip = &idio24gpio->chip;
unsigned long irq_mask;
int gpio;
raw_spin_lock(&idio24gpio->lock);
/* Read Change-Of-State status */
irq_status = ioread32(&idio24gpio->reg->cos0_7);
raw_spin_unlock(&idio24gpio->lock);
/* Make sure our device generated IRQ */
if (!irq_status)
return IRQ_NONE;
/* Handle only unmasked IRQ */
irq_mask = idio24gpio->irq_mask & irq_status;
for_each_set_bit(gpio, &irq_mask, chip->ngpio - 24)
generic_handle_irq(irq_find_mapping(chip->irq.domain,
gpio + 24));
raw_spin_lock(&idio24gpio->lock);
/* Clear Change-Of-State status */
iowrite32(irq_status, &idio24gpio->reg->cos0_7);
raw_spin_unlock(&idio24gpio->lock);
return IRQ_HANDLED;
}
#define IDIO_24_NGPIO 56
static const char *idio_24_names[IDIO_24_NGPIO] = {
"OUT0", "OUT1", "OUT2", "OUT3", "OUT4", "OUT5", "OUT6", "OUT7",
"OUT8", "OUT9", "OUT10", "OUT11", "OUT12", "OUT13", "OUT14", "OUT15",
"OUT16", "OUT17", "OUT18", "OUT19", "OUT20", "OUT21", "OUT22", "OUT23",
"IIN0", "IIN1", "IIN2", "IIN3", "IIN4", "IIN5", "IIN6", "IIN7",
"IIN8", "IIN9", "IIN10", "IIN11", "IIN12", "IIN13", "IIN14", "IIN15",
"IIN16", "IIN17", "IIN18", "IIN19", "IIN20", "IIN21", "IIN22", "IIN23",
"TTL0", "TTL1", "TTL2", "TTL3", "TTL4", "TTL5", "TTL6", "TTL7"
};
static int idio_24_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
struct device *const dev = &pdev->dev;
struct idio_24_gpio *idio24gpio;
int err;
const size_t pci_bar_index = 2;
const char *const name = pci_name(pdev);
idio24gpio = devm_kzalloc(dev, sizeof(*idio24gpio), GFP_KERNEL);
if (!idio24gpio)
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;
}
idio24gpio->reg = pcim_iomap_table(pdev)[pci_bar_index];
idio24gpio->chip.label = name;
idio24gpio->chip.parent = dev;
idio24gpio->chip.owner = THIS_MODULE;
idio24gpio->chip.base = -1;
idio24gpio->chip.ngpio = IDIO_24_NGPIO;
idio24gpio->chip.names = idio_24_names;
idio24gpio->chip.get_direction = idio_24_gpio_get_direction;
idio24gpio->chip.direction_input = idio_24_gpio_direction_input;
idio24gpio->chip.direction_output = idio_24_gpio_direction_output;
idio24gpio->chip.get = idio_24_gpio_get;
idio24gpio->chip.get_multiple = idio_24_gpio_get_multiple;
idio24gpio->chip.set = idio_24_gpio_set;
idio24gpio->chip.set_multiple = idio_24_gpio_set_multiple;
raw_spin_lock_init(&idio24gpio->lock);
/* Software board reset */
iowrite8(0, &idio24gpio->reg->soft_reset);
err = devm_gpiochip_add_data(dev, &idio24gpio->chip, idio24gpio);
if (err) {
dev_err(dev, "GPIO registering failed (%d)\n", err);
return err;
}
err = gpiochip_irqchip_add(&idio24gpio->chip, &idio_24_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, pdev->irq, idio_24_irq_handler, IRQF_SHARED,
name, idio24gpio);
if (err) {
dev_err(dev, "IRQ handler registering failed (%d)\n", err);
return err;
}
return 0;
}
static const struct pci_device_id idio_24_pci_dev_id[] = {
{ PCI_DEVICE(0x494F, 0x0FD0) }, { PCI_DEVICE(0x494F, 0x0BD0) },
{ PCI_DEVICE(0x494F, 0x07D0) }, { PCI_DEVICE(0x494F, 0x0FC0) },
{ 0 }
};
MODULE_DEVICE_TABLE(pci, idio_24_pci_dev_id);
static struct pci_driver idio_24_driver = {
.name = "pcie-idio-24",
.id_table = idio_24_pci_dev_id,
.probe = idio_24_probe
};
module_pci_driver(idio_24_driver);
MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
MODULE_DESCRIPTION("ACCES PCIe-IDIO-24 GPIO driver");
MODULE_LICENSE("GPL v2");