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// SPDX-License-Identifier: GPL-2.0-only
/*
* GPIO driver for the ACCES 104-DIO-48E series
* Copyright (C) 2016 William Breathitt Gray
*
* This driver supports the following ACCES devices: 104-DIO-48E and
* 104-DIO-24E.
*/
#include <linux/bits.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>
#include <linux/types.h>
#include "gpio-i8255.h"
MODULE_IMPORT_NS(I8255);
#define DIO48E_EXTENT 16
#define MAX_NUM_DIO48E max_num_isa_dev(DIO48E_EXTENT)
static unsigned int base[MAX_NUM_DIO48E];
static unsigned int num_dio48e;
module_param_hw_array(base, uint, ioport, &num_dio48e, 0);
MODULE_PARM_DESC(base, "ACCES 104-DIO-48E base addresses");
static unsigned int irq[MAX_NUM_DIO48E];
static unsigned int num_irq;
module_param_hw_array(irq, uint, irq, &num_irq, 0);
MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
#define DIO48E_NUM_PPI 2
/**
* struct dio48e_reg - device register structure
* @ppi: Programmable Peripheral Interface groups
* @enable_buffer: Enable/Disable Buffer groups
* @unused1: Unused
* @enable_interrupt: Write: Enable Interrupt
* Read: Disable Interrupt
* @unused2: Unused
* @enable_counter: Write: Enable Counter/Timer Addressing
* Read: Disable Counter/Timer Addressing
* @unused3: Unused
* @clear_interrupt: Clear Interrupt
*/
struct dio48e_reg {
struct i8255 ppi[DIO48E_NUM_PPI];
u8 enable_buffer[DIO48E_NUM_PPI];
u8 unused1;
u8 enable_interrupt;
u8 unused2;
u8 enable_counter;
u8 unused3;
u8 clear_interrupt;
};
/**
* struct dio48e_gpio - GPIO device private data structure
* @chip: instance of the gpio_chip
* @ppi_state: PPI device states
* @lock: synchronization lock to prevent I/O race conditions
* @reg: I/O address offset for the device registers
* @irq_mask: I/O bits affected by interrupts
*/
struct dio48e_gpio {
struct gpio_chip chip;
struct i8255_state ppi_state[DIO48E_NUM_PPI];
raw_spinlock_t lock;
struct dio48e_reg __iomem *reg;
unsigned char irq_mask;
};
static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
if (i8255_get_direction(dio48egpio->ppi_state, offset))
return GPIO_LINE_DIRECTION_IN;
return GPIO_LINE_DIRECTION_OUT;
}
static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
i8255_direction_input(dio48egpio->reg->ppi, dio48egpio->ppi_state,
offset);
return 0;
}
static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
i8255_direction_output(dio48egpio->reg->ppi, dio48egpio->ppi_state,
offset, value);
return 0;
}
static int dio48e_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
return i8255_get(dio48egpio->reg->ppi, offset);
}
static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
unsigned long *bits)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
i8255_get_multiple(dio48egpio->reg->ppi, mask, bits, chip->ngpio);
return 0;
}
static void dio48e_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
i8255_set(dio48egpio->reg->ppi, dio48egpio->ppi_state, offset, value);
}
static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
i8255_set_multiple(dio48egpio->reg->ppi, dio48egpio->ppi_state, mask,
bits, chip->ngpio);
}
static void dio48e_irq_ack(struct irq_data *data)
{
}
static void dio48e_irq_mask(struct irq_data *data)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
const unsigned long offset = irqd_to_hwirq(data);
unsigned long flags;
/* only bit 3 on each respective Port C supports interrupts */
if (offset != 19 && offset != 43)
return;
raw_spin_lock_irqsave(&dio48egpio->lock, flags);
if (offset == 19)
dio48egpio->irq_mask &= ~BIT(0);
else
dio48egpio->irq_mask &= ~BIT(1);
gpiochip_disable_irq(chip, offset);
if (!dio48egpio->irq_mask)
/* disable interrupts */
ioread8(&dio48egpio->reg->enable_interrupt);
raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
}
static void dio48e_irq_unmask(struct irq_data *data)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
const unsigned long offset = irqd_to_hwirq(data);
unsigned long flags;
/* only bit 3 on each respective Port C supports interrupts */
if (offset != 19 && offset != 43)
return;
raw_spin_lock_irqsave(&dio48egpio->lock, flags);
if (!dio48egpio->irq_mask) {
/* enable interrupts */
iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
iowrite8(0x00, &dio48egpio->reg->enable_interrupt);
}
gpiochip_enable_irq(chip, offset);
if (offset == 19)
dio48egpio->irq_mask |= BIT(0);
else
dio48egpio->irq_mask |= BIT(1);
raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
}
static int dio48e_irq_set_type(struct irq_data *data, unsigned int flow_type)
{
const unsigned long offset = irqd_to_hwirq(data);
/* only bit 3 on each respective Port C supports interrupts */
if (offset != 19 && offset != 43)
return -EINVAL;
if (flow_type != IRQ_TYPE_NONE && flow_type != IRQ_TYPE_EDGE_RISING)
return -EINVAL;
return 0;
}
static const struct irq_chip dio48e_irqchip = {
.name = "104-dio-48e",
.irq_ack = dio48e_irq_ack,
.irq_mask = dio48e_irq_mask,
.irq_unmask = dio48e_irq_unmask,
.irq_set_type = dio48e_irq_set_type,
.flags = IRQCHIP_IMMUTABLE,
GPIOCHIP_IRQ_RESOURCE_HELPERS,
};
static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
{
struct dio48e_gpio *const dio48egpio = dev_id;
struct gpio_chip *const chip = &dio48egpio->chip;
const unsigned long irq_mask = dio48egpio->irq_mask;
unsigned long gpio;
for_each_set_bit(gpio, &irq_mask, 2)
generic_handle_domain_irq(chip->irq.domain,
19 + gpio*24);
raw_spin_lock(&dio48egpio->lock);
iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
raw_spin_unlock(&dio48egpio->lock);
return IRQ_HANDLED;
}
#define DIO48E_NGPIO 48
static const char *dio48e_names[DIO48E_NGPIO] = {
"PPI Group 0 Port A 0", "PPI Group 0 Port A 1", "PPI Group 0 Port A 2",
"PPI Group 0 Port A 3", "PPI Group 0 Port A 4", "PPI Group 0 Port A 5",
"PPI Group 0 Port A 6", "PPI Group 0 Port A 7", "PPI Group 0 Port B 0",
"PPI Group 0 Port B 1", "PPI Group 0 Port B 2", "PPI Group 0 Port B 3",
"PPI Group 0 Port B 4", "PPI Group 0 Port B 5", "PPI Group 0 Port B 6",
"PPI Group 0 Port B 7", "PPI Group 0 Port C 0", "PPI Group 0 Port C 1",
"PPI Group 0 Port C 2", "PPI Group 0 Port C 3", "PPI Group 0 Port C 4",
"PPI Group 0 Port C 5", "PPI Group 0 Port C 6", "PPI Group 0 Port C 7",
"PPI Group 1 Port A 0", "PPI Group 1 Port A 1", "PPI Group 1 Port A 2",
"PPI Group 1 Port A 3", "PPI Group 1 Port A 4", "PPI Group 1 Port A 5",
"PPI Group 1 Port A 6", "PPI Group 1 Port A 7", "PPI Group 1 Port B 0",
"PPI Group 1 Port B 1", "PPI Group 1 Port B 2", "PPI Group 1 Port B 3",
"PPI Group 1 Port B 4", "PPI Group 1 Port B 5", "PPI Group 1 Port B 6",
"PPI Group 1 Port B 7", "PPI Group 1 Port C 0", "PPI Group 1 Port C 1",
"PPI Group 1 Port C 2", "PPI Group 1 Port C 3", "PPI Group 1 Port C 4",
"PPI Group 1 Port C 5", "PPI Group 1 Port C 6", "PPI Group 1 Port C 7"
};
static int dio48e_irq_init_hw(struct gpio_chip *gc)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(gc);
/* Disable IRQ by default */
ioread8(&dio48egpio->reg->enable_interrupt);
return 0;
}
static void dio48e_init_ppi(struct i8255 __iomem *const ppi,
struct i8255_state *const ppi_state)
{
const unsigned long ngpio = 24;
const unsigned long mask = GENMASK(ngpio - 1, 0);
const unsigned long bits = 0;
unsigned long i;
/* Initialize all GPIO to output 0 */
for (i = 0; i < DIO48E_NUM_PPI; i++) {
i8255_mode0_output(&ppi[i]);
i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio);
}
}
static int dio48e_probe(struct device *dev, unsigned int id)
{
struct dio48e_gpio *dio48egpio;
const char *const name = dev_name(dev);
struct gpio_irq_chip *girq;
int err;
dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
if (!dio48egpio)
return -ENOMEM;
if (!devm_request_region(dev, base[id], DIO48E_EXTENT, name)) {
dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
base[id], base[id] + DIO48E_EXTENT);
return -EBUSY;
}
dio48egpio->reg = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
if (!dio48egpio->reg)
return -ENOMEM;
dio48egpio->chip.label = name;
dio48egpio->chip.parent = dev;
dio48egpio->chip.owner = THIS_MODULE;
dio48egpio->chip.base = -1;
dio48egpio->chip.ngpio = DIO48E_NGPIO;
dio48egpio->chip.names = dio48e_names;
dio48egpio->chip.get_direction = dio48e_gpio_get_direction;
dio48egpio->chip.direction_input = dio48e_gpio_direction_input;
dio48egpio->chip.direction_output = dio48e_gpio_direction_output;
dio48egpio->chip.get = dio48e_gpio_get;
dio48egpio->chip.get_multiple = dio48e_gpio_get_multiple;
dio48egpio->chip.set = dio48e_gpio_set;
dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
girq = &dio48egpio->chip.irq;
gpio_irq_chip_set_chip(girq, &dio48e_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 = dio48e_irq_init_hw;
raw_spin_lock_init(&dio48egpio->lock);
i8255_state_init(dio48egpio->ppi_state, DIO48E_NUM_PPI);
dio48e_init_ppi(dio48egpio->reg->ppi, dio48egpio->ppi_state);
err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
if (err) {
dev_err(dev, "GPIO registering failed (%d)\n", err);
return err;
}
err = devm_request_irq(dev, irq[id], dio48e_irq_handler, 0, name,
dio48egpio);
if (err) {
dev_err(dev, "IRQ handler registering failed (%d)\n", err);
return err;
}
return 0;
}
static struct isa_driver dio48e_driver = {
.probe = dio48e_probe,
.driver = {
.name = "104-dio-48e"
},
};
module_isa_driver_with_irq(dio48e_driver, num_dio48e, num_irq);
MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
MODULE_DESCRIPTION("ACCES 104-DIO-48E GPIO driver");
MODULE_LICENSE("GPL v2");
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