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alistair23-linux/drivers/gpio/gpio-ws16c48.c
Thomas Gleixner 1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00

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// 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;
unsigned 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);
return !!(ws16c48gpio->io_state[port] & mask);
}
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;
outb(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;
outb(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 = inb(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);
const unsigned int gpio_reg_size = 8;
size_t i;
const size_t num_ports = chip->ngpio / gpio_reg_size;
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 < num_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(ws16c48gpio->base + i);
/* store acquired bits at respective bits array offset */
bits[word_index] |= (port_state << word_offset) & word_mask;
}
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;
outb(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 int i;
const unsigned int gpio_reg_size = 8;
unsigned int port;
unsigned int iomask;
unsigned int bitmask;
unsigned long flags;
/* set bits are evaluated a gpio register size at a time */
for (i = 0; i < chip->ngpio; i += gpio_reg_size) {
/* no more set bits in this mask word; skip to the next word */
if (!mask[BIT_WORD(i)]) {
i = (BIT_WORD(i) + 1) * BITS_PER_LONG - gpio_reg_size;
continue;
}
port = i / gpio_reg_size;
/* mask out GPIO configured for input */
iomask = mask[BIT_WORD(i)] & ~ws16c48gpio->io_state[port];
bitmask = iomask & bits[BIT_WORD(i)];
raw_spin_lock_irqsave(&ws16c48gpio->lock, flags);
/* update output state data and set device gpio register */
ws16c48gpio->out_state[port] &= ~iomask;
ws16c48gpio->out_state[port] |= bitmask;
outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port);
raw_spin_unlock_irqrestore(&ws16c48gpio->lock, flags);
/* prepare for next gpio register set */
mask[BIT_WORD(i)] >>= gpio_reg_size;
bits[BIT_WORD(i)] >>= gpio_reg_size;
}
}
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);
outb(0x80, ws16c48gpio->base + 7);
outb(port_state & ~mask, ws16c48gpio->base + 8 + port);
outb(port_state | mask, ws16c48gpio->base + 8 + port);
outb(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;
outb(0x80, ws16c48gpio->base + 7);
outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port);
outb(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;
outb(0x80, ws16c48gpio->base + 7);
outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port);
outb(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;
}
outb(0x40, ws16c48gpio->base + 7);
outb(ws16c48gpio->flow_mask >> (8*port), ws16c48gpio->base + 8 + port);
outb(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 = inb(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 = inb(ws16c48gpio->base + 8 + port);
for_each_set_bit(gpio, &int_id, 8)
generic_handle_irq(irq_find_mapping(
chip->irq.domain, gpio + 8*port));
}
int_pending = inb(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_probe(struct device *dev, unsigned int id)
{
struct ws16c48_gpio *ws16c48gpio;
const char *const name = dev_name(dev);
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->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;
ws16c48gpio->base = base[id];
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;
}
/* Disable IRQ by default */
outb(0x80, base[id] + 7);
outb(0, base[id] + 8);
outb(0, base[id] + 9);
outb(0, base[id] + 10);
outb(0xC0, base[id] + 7);
err = gpiochip_irqchip_add(&ws16c48gpio->chip, &ws16c48_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], 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");
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