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Release 4.14 drivers/gpio/gpio-104-dio-48e.c

Directory: drivers/gpio
/*
 * GPIO driver for the ACCES 104-DIO-48E series
 * Copyright (C) 2016 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-DIO-48E and
 * 104-DIO-24E.
 */
#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 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];
module_param_hw_array(irq, uint, irq, NULL, 0);
MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");

/**
 * struct dio48e_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
 * @control:    Control registers state
 * @lock:       synchronization lock to prevent I/O race conditions
 * @base:       base port address of the GPIO device
 * @irq_mask:   I/O bits affected by interrupts
 */

struct dio48e_gpio {
	
struct gpio_chip chip;
	
unsigned char io_state[6];
	
unsigned char out_state[6];
	
unsigned char control[2];
	
raw_spinlock_t lock;
	
unsigned base;
	
unsigned char irq_mask;
};


static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned offset) { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned port = offset / 8; const unsigned mask = BIT(offset % 8); return !!(dio48egpio->io_state[port] & mask); }

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static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned io_port = offset / 8; const unsigned int control_port = io_port / 3; const unsigned control_addr = dio48egpio->base + 3 + control_port*4; unsigned long flags; unsigned control; raw_spin_lock_irqsave(&dio48egpio->lock, flags); /* Check if configuring Port C */ if (io_port == 2 || io_port == 5) { /* Port C can be configured by nibble */ if (offset % 8 > 3) { dio48egpio->io_state[io_port] |= 0xF0; dio48egpio->control[control_port] |= BIT(3); } else { dio48egpio->io_state[io_port] |= 0x0F; dio48egpio->control[control_port] |= BIT(0); } } else { dio48egpio->io_state[io_port] |= 0xFF; if (io_port == 0 || io_port == 3) dio48egpio->control[control_port] |= BIT(4); else dio48egpio->control[control_port] |= BIT(1); } control = BIT(7) | dio48egpio->control[control_port]; outb(control, control_addr); control &= ~BIT(7); outb(control, control_addr); raw_spin_unlock_irqrestore(&dio48egpio->lock, flags); return 0; }

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static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned offset, int value) { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned io_port = offset / 8; const unsigned int control_port = io_port / 3; const unsigned mask = BIT(offset % 8); const unsigned control_addr = dio48egpio->base + 3 + control_port*4; const unsigned out_port = (io_port > 2) ? io_port + 1 : io_port; unsigned long flags; unsigned control; raw_spin_lock_irqsave(&dio48egpio->lock, flags); /* Check if configuring Port C */ if (io_port == 2 || io_port == 5) { /* Port C can be configured by nibble */ if (offset % 8 > 3) { dio48egpio->io_state[io_port] &= 0x0F; dio48egpio->control[control_port] &= ~BIT(3); } else { dio48egpio->io_state[io_port] &= 0xF0; dio48egpio->control[control_port] &= ~BIT(0); } } else { dio48egpio->io_state[io_port] &= 0x00; if (io_port == 0 || io_port == 3) dio48egpio->control[control_port] &= ~BIT(4); else dio48egpio->control[control_port] &= ~BIT(1); } if (value) dio48egpio->out_state[io_port] |= mask; else dio48egpio->out_state[io_port] &= ~mask; control = BIT(7) | dio48egpio->control[control_port]; outb(control, control_addr); outb(dio48egpio->out_state[io_port], dio48egpio->base + out_port); control &= ~BIT(7); outb(control, control_addr); raw_spin_unlock_irqrestore(&dio48egpio->lock, flags); return 0; }

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static int dio48e_gpio_get(struct gpio_chip *chip, unsigned offset) { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned port = offset / 8; const unsigned mask = BIT(offset % 8); const unsigned in_port = (port > 2) ? port + 1 : port; unsigned long flags; unsigned port_state; raw_spin_lock_irqsave(&dio48egpio->lock, flags); /* ensure that GPIO is set for input */ if (!(dio48egpio->io_state[port] & mask)) { raw_spin_unlock_irqrestore(&dio48egpio->lock, flags); return -EINVAL; } port_state = inb(dio48egpio->base + in_port); raw_spin_unlock_irqrestore(&dio48egpio->lock, flags); return !!(port_state & mask); }

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static void dio48e_gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip); const unsigned port = offset / 8; const unsigned mask = BIT(offset % 8); const unsigned out_port = (port > 2) ? port + 1 : port; unsigned long flags; raw_spin_lock_irqsave(&dio48egpio->lock, flags); if (value) dio48egpio->out_state[port] |= mask; else dio48egpio->out_state[port] &= ~mask; outb(dio48egpio->out_state[port], dio48egpio->base + out_port); raw_spin_unlock_irqrestore(&dio48egpio->lock, flags); }

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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); unsigned int i; const unsigned int gpio_reg_size = 8; unsigned int port; unsigned int out_port; 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; out_port = (port > 2) ? port + 1 : port; bitmask = mask[BIT_WORD(i)] & bits[BIT_WORD(i)]; raw_spin_lock_irqsave(&dio48egpio->lock, flags); /* update output state data and set device gpio register */ dio48egpio->out_state[port] &= ~mask[BIT_WORD(i)]; dio48egpio->out_state[port] |= bitmask; outb(dio48egpio->out_state[port], dio48egpio->base + out_port); raw_spin_unlock_irqrestore(&dio48egpio->lock, flags); /* prepare for next gpio register set */ mask[BIT_WORD(i)] >>= gpio_reg_size; bits[BIT_WORD(i)] >>= gpio_reg_size; } }

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static void dio48e_irq_ack(struct irq_data *data) { }

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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); if (!dio48egpio->irq_mask) /* disable interrupts */ inb(dio48egpio->base + 0xB); raw_spin_unlock_irqrestore(&dio48egpio->lock, flags); }

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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 */ outb(0x00, dio48egpio->base + 0xF); outb(0x00, dio48egpio->base + 0xB); } if (offset == 19) dio48egpio->irq_mask |= BIT(0); else dio48egpio->irq_mask |= BIT(1); raw_spin_unlock_irqrestore(&dio48egpio->lock, flags); }

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static int dio48e_irq_set_type(struct irq_data *data, unsigned 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; }

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static 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 };
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_irq(irq_find_mapping(chip->irqdomain, 19 + gpio*24)); raw_spin_lock(&dio48egpio->lock); outb(0x00, dio48egpio->base + 0xF); raw_spin_unlock(&dio48egpio->lock); return IRQ_HANDLED; }

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#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_probe(struct device *dev, unsigned int id) { struct dio48e_gpio *dio48egpio; const char *const name = dev_name(dev); 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->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.set = dio48e_gpio_set; dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple; dio48egpio->base = base[id]; raw_spin_lock_init(&dio48egpio->lock); err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio); if (err) { dev_err(dev, "GPIO registering failed (%d)\n", err); return err; } /* initialize all GPIO as output */ outb(0x80, base[id] + 3); outb(0x00, base[id]); outb(0x00, base[id] + 1); outb(0x00, base[id] + 2); outb(0x00, base[id] + 3); outb(0x80, base[id] + 7); outb(0x00, base[id] + 4); outb(0x00, base[id] + 5); outb(0x00, base[id] + 6); outb(0x00, base[id] + 7); /* disable IRQ by default */ inb(base[id] + 0xB); err = gpiochip_irqchip_add(&dio48egpio->chip, &dio48e_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], dio48e_irq_handler, 0, name, dio48egpio); if (err) { dev_err(dev, "IRQ handler registering failed (%d)\n", err); return err; } return 0; }

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static struct isa_driver dio48e_driver = { .probe = dio48e_probe, .driver = { .name = "104-dio-48e" }, }; module_isa_driver(dio48e_driver, num_dio48e); 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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Directory: drivers/gpio
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