linux/drivers/gpio/gpio-adnp.c
Linus Walleij 0752e169ba gpio: adnp: switch to use irqchip helpers
This switches the ADNP GPIO driver to use the gpiolib
irqchip helpers. Also do some random refactoring to make it
look like most other GPIO drivers.

Cc: Roland Stigge <stigge@antcom.de>
Cc: Lars Poeschel <poeschel@lemonage.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-09-02 10:44:01 +02:00

562 lines
12 KiB
C

/*
* Copyright (C) 2011-2012 Avionic Design GmbH
*
* 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.
*/
#include <linux/gpio/driver.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#define GPIO_DDR(gpio) (0x00 << (gpio)->reg_shift)
#define GPIO_PLR(gpio) (0x01 << (gpio)->reg_shift)
#define GPIO_IER(gpio) (0x02 << (gpio)->reg_shift)
#define GPIO_ISR(gpio) (0x03 << (gpio)->reg_shift)
#define GPIO_PTR(gpio) (0x04 << (gpio)->reg_shift)
struct adnp {
struct i2c_client *client;
struct gpio_chip gpio;
unsigned int reg_shift;
struct mutex i2c_lock;
struct mutex irq_lock;
u8 *irq_enable;
u8 *irq_level;
u8 *irq_rise;
u8 *irq_fall;
u8 *irq_high;
u8 *irq_low;
};
static inline struct adnp *to_adnp(struct gpio_chip *chip)
{
return container_of(chip, struct adnp, gpio);
}
static int adnp_read(struct adnp *adnp, unsigned offset, uint8_t *value)
{
int err;
err = i2c_smbus_read_byte_data(adnp->client, offset);
if (err < 0) {
dev_err(adnp->gpio.dev, "%s failed: %d\n",
"i2c_smbus_read_byte_data()", err);
return err;
}
*value = err;
return 0;
}
static int adnp_write(struct adnp *adnp, unsigned offset, uint8_t value)
{
int err;
err = i2c_smbus_write_byte_data(adnp->client, offset, value);
if (err < 0) {
dev_err(adnp->gpio.dev, "%s failed: %d\n",
"i2c_smbus_write_byte_data()", err);
return err;
}
return 0;
}
static int adnp_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct adnp *adnp = to_adnp(chip);
unsigned int reg = offset >> adnp->reg_shift;
unsigned int pos = offset & 7;
u8 value;
int err;
err = adnp_read(adnp, GPIO_PLR(adnp) + reg, &value);
if (err < 0)
return err;
return (value & BIT(pos)) ? 1 : 0;
}
static void __adnp_gpio_set(struct adnp *adnp, unsigned offset, int value)
{
unsigned int reg = offset >> adnp->reg_shift;
unsigned int pos = offset & 7;
int err;
u8 val;
err = adnp_read(adnp, GPIO_PLR(adnp) + reg, &val);
if (err < 0)
return;
if (value)
val |= BIT(pos);
else
val &= ~BIT(pos);
adnp_write(adnp, GPIO_PLR(adnp) + reg, val);
}
static void adnp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct adnp *adnp = to_adnp(chip);
mutex_lock(&adnp->i2c_lock);
__adnp_gpio_set(adnp, offset, value);
mutex_unlock(&adnp->i2c_lock);
}
static int adnp_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct adnp *adnp = to_adnp(chip);
unsigned int reg = offset >> adnp->reg_shift;
unsigned int pos = offset & 7;
u8 value;
int err;
mutex_lock(&adnp->i2c_lock);
err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &value);
if (err < 0)
goto out;
value &= ~BIT(pos);
err = adnp_write(adnp, GPIO_DDR(adnp) + reg, value);
if (err < 0)
goto out;
err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &value);
if (err < 0)
goto out;
if (err & BIT(pos))
err = -EACCES;
err = 0;
out:
mutex_unlock(&adnp->i2c_lock);
return err;
}
static int adnp_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
struct adnp *adnp = to_adnp(chip);
unsigned int reg = offset >> adnp->reg_shift;
unsigned int pos = offset & 7;
int err;
u8 val;
mutex_lock(&adnp->i2c_lock);
err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &val);
if (err < 0)
goto out;
val |= BIT(pos);
err = adnp_write(adnp, GPIO_DDR(adnp) + reg, val);
if (err < 0)
goto out;
err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &val);
if (err < 0)
goto out;
if (!(val & BIT(pos))) {
err = -EPERM;
goto out;
}
__adnp_gpio_set(adnp, offset, value);
err = 0;
out:
mutex_unlock(&adnp->i2c_lock);
return err;
}
static void adnp_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
struct adnp *adnp = to_adnp(chip);
unsigned int num_regs = 1 << adnp->reg_shift, i, j;
int err;
for (i = 0; i < num_regs; i++) {
u8 ddr, plr, ier, isr;
mutex_lock(&adnp->i2c_lock);
err = adnp_read(adnp, GPIO_DDR(adnp) + i, &ddr);
if (err < 0) {
mutex_unlock(&adnp->i2c_lock);
return;
}
err = adnp_read(adnp, GPIO_PLR(adnp) + i, &plr);
if (err < 0) {
mutex_unlock(&adnp->i2c_lock);
return;
}
err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier);
if (err < 0) {
mutex_unlock(&adnp->i2c_lock);
return;
}
err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr);
if (err < 0) {
mutex_unlock(&adnp->i2c_lock);
return;
}
mutex_unlock(&adnp->i2c_lock);
for (j = 0; j < 8; j++) {
unsigned int bit = (i << adnp->reg_shift) + j;
const char *direction = "input ";
const char *level = "low ";
const char *interrupt = "disabled";
const char *pending = "";
if (ddr & BIT(j))
direction = "output";
if (plr & BIT(j))
level = "high";
if (ier & BIT(j))
interrupt = "enabled ";
if (isr & BIT(j))
pending = "pending";
seq_printf(s, "%2u: %s %s IRQ %s %s\n", bit,
direction, level, interrupt, pending);
}
}
}
static int adnp_gpio_setup(struct adnp *adnp, unsigned int num_gpios)
{
struct gpio_chip *chip = &adnp->gpio;
int err;
adnp->reg_shift = get_count_order(num_gpios) - 3;
chip->direction_input = adnp_gpio_direction_input;
chip->direction_output = adnp_gpio_direction_output;
chip->get = adnp_gpio_get;
chip->set = adnp_gpio_set;
chip->can_sleep = true;
if (IS_ENABLED(CONFIG_DEBUG_FS))
chip->dbg_show = adnp_gpio_dbg_show;
chip->base = -1;
chip->ngpio = num_gpios;
chip->label = adnp->client->name;
chip->dev = &adnp->client->dev;
chip->of_node = chip->dev->of_node;
chip->owner = THIS_MODULE;
err = gpiochip_add(chip);
if (err)
return err;
return 0;
}
static irqreturn_t adnp_irq(int irq, void *data)
{
struct adnp *adnp = data;
unsigned int num_regs, i;
num_regs = 1 << adnp->reg_shift;
for (i = 0; i < num_regs; i++) {
unsigned int base = i << adnp->reg_shift, bit;
u8 changed, level, isr, ier;
unsigned long pending;
int err;
mutex_lock(&adnp->i2c_lock);
err = adnp_read(adnp, GPIO_PLR(adnp) + i, &level);
if (err < 0) {
mutex_unlock(&adnp->i2c_lock);
continue;
}
err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr);
if (err < 0) {
mutex_unlock(&adnp->i2c_lock);
continue;
}
err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier);
if (err < 0) {
mutex_unlock(&adnp->i2c_lock);
continue;
}
mutex_unlock(&adnp->i2c_lock);
/* determine pins that changed levels */
changed = level ^ adnp->irq_level[i];
/* compute edge-triggered interrupts */
pending = changed & ((adnp->irq_fall[i] & ~level) |
(adnp->irq_rise[i] & level));
/* add in level-triggered interrupts */
pending |= (adnp->irq_high[i] & level) |
(adnp->irq_low[i] & ~level);
/* mask out non-pending and disabled interrupts */
pending &= isr & ier;
for_each_set_bit(bit, &pending, 8) {
unsigned int child_irq;
child_irq = irq_find_mapping(adnp->gpio.irqdomain,
base + bit);
handle_nested_irq(child_irq);
}
}
return IRQ_HANDLED;
}
static void adnp_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct adnp *adnp = to_adnp(gc);
unsigned int reg = d->hwirq >> adnp->reg_shift;
unsigned int pos = d->hwirq & 7;
adnp->irq_enable[reg] &= ~BIT(pos);
}
static void adnp_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct adnp *adnp = to_adnp(gc);
unsigned int reg = d->hwirq >> adnp->reg_shift;
unsigned int pos = d->hwirq & 7;
adnp->irq_enable[reg] |= BIT(pos);
}
static int adnp_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct adnp *adnp = to_adnp(gc);
unsigned int reg = d->hwirq >> adnp->reg_shift;
unsigned int pos = d->hwirq & 7;
if (type & IRQ_TYPE_EDGE_RISING)
adnp->irq_rise[reg] |= BIT(pos);
else
adnp->irq_rise[reg] &= ~BIT(pos);
if (type & IRQ_TYPE_EDGE_FALLING)
adnp->irq_fall[reg] |= BIT(pos);
else
adnp->irq_fall[reg] &= ~BIT(pos);
if (type & IRQ_TYPE_LEVEL_HIGH)
adnp->irq_high[reg] |= BIT(pos);
else
adnp->irq_high[reg] &= ~BIT(pos);
if (type & IRQ_TYPE_LEVEL_LOW)
adnp->irq_low[reg] |= BIT(pos);
else
adnp->irq_low[reg] &= ~BIT(pos);
return 0;
}
static void adnp_irq_bus_lock(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct adnp *adnp = to_adnp(gc);
mutex_lock(&adnp->irq_lock);
}
static void adnp_irq_bus_unlock(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct adnp *adnp = to_adnp(gc);
unsigned int num_regs = 1 << adnp->reg_shift, i;
mutex_lock(&adnp->i2c_lock);
for (i = 0; i < num_regs; i++)
adnp_write(adnp, GPIO_IER(adnp) + i, adnp->irq_enable[i]);
mutex_unlock(&adnp->i2c_lock);
mutex_unlock(&adnp->irq_lock);
}
static struct irq_chip adnp_irq_chip = {
.name = "gpio-adnp",
.irq_mask = adnp_irq_mask,
.irq_unmask = adnp_irq_unmask,
.irq_set_type = adnp_irq_set_type,
.irq_bus_lock = adnp_irq_bus_lock,
.irq_bus_sync_unlock = adnp_irq_bus_unlock,
};
static int adnp_irq_setup(struct adnp *adnp)
{
unsigned int num_regs = 1 << adnp->reg_shift, i;
struct gpio_chip *chip = &adnp->gpio;
int err;
mutex_init(&adnp->irq_lock);
/*
* Allocate memory to keep track of the current level and trigger
* modes of the interrupts. To avoid multiple allocations, a single
* large buffer is allocated and pointers are setup to point at the
* corresponding offsets. For consistency, the layout of the buffer
* is chosen to match the register layout of the hardware in that
* each segment contains the corresponding bits for all interrupts.
*/
adnp->irq_enable = devm_kzalloc(chip->dev, num_regs * 6, GFP_KERNEL);
if (!adnp->irq_enable)
return -ENOMEM;
adnp->irq_level = adnp->irq_enable + (num_regs * 1);
adnp->irq_rise = adnp->irq_enable + (num_regs * 2);
adnp->irq_fall = adnp->irq_enable + (num_regs * 3);
adnp->irq_high = adnp->irq_enable + (num_regs * 4);
adnp->irq_low = adnp->irq_enable + (num_regs * 5);
for (i = 0; i < num_regs; i++) {
/*
* Read the initial level of all pins to allow the emulation
* of edge triggered interrupts.
*/
err = adnp_read(adnp, GPIO_PLR(adnp) + i, &adnp->irq_level[i]);
if (err < 0)
return err;
/* disable all interrupts */
err = adnp_write(adnp, GPIO_IER(adnp) + i, 0);
if (err < 0)
return err;
adnp->irq_enable[i] = 0x00;
}
err = devm_request_threaded_irq(chip->dev, adnp->client->irq,
NULL, adnp_irq,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
dev_name(chip->dev), adnp);
if (err != 0) {
dev_err(chip->dev, "can't request IRQ#%d: %d\n",
adnp->client->irq, err);
return err;
}
err = gpiochip_irqchip_add(chip,
&adnp_irq_chip,
0,
handle_simple_irq,
IRQ_TYPE_NONE);
if (err) {
dev_err(chip->dev,
"could not connect irqchip to gpiochip\n");
return err;
}
return 0;
}
static int adnp_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device_node *np = client->dev.of_node;
struct adnp *adnp;
u32 num_gpios;
int err;
err = of_property_read_u32(np, "nr-gpios", &num_gpios);
if (err < 0)
return err;
client->irq = irq_of_parse_and_map(np, 0);
if (!client->irq)
return -EPROBE_DEFER;
adnp = devm_kzalloc(&client->dev, sizeof(*adnp), GFP_KERNEL);
if (!adnp)
return -ENOMEM;
mutex_init(&adnp->i2c_lock);
adnp->client = client;
err = adnp_gpio_setup(adnp, num_gpios);
if (err)
return err;
if (of_find_property(np, "interrupt-controller", NULL)) {
err = adnp_irq_setup(adnp);
if (err)
return err;
}
i2c_set_clientdata(client, adnp);
return 0;
}
static int adnp_i2c_remove(struct i2c_client *client)
{
struct adnp *adnp = i2c_get_clientdata(client);
gpiochip_remove(&adnp->gpio);
return 0;
}
static const struct i2c_device_id adnp_i2c_id[] = {
{ "gpio-adnp" },
{ },
};
MODULE_DEVICE_TABLE(i2c, adnp_i2c_id);
static const struct of_device_id adnp_of_match[] = {
{ .compatible = "ad,gpio-adnp", },
{ },
};
MODULE_DEVICE_TABLE(of, adnp_of_match);
static struct i2c_driver adnp_i2c_driver = {
.driver = {
.name = "gpio-adnp",
.owner = THIS_MODULE,
.of_match_table = adnp_of_match,
},
.probe = adnp_i2c_probe,
.remove = adnp_i2c_remove,
.id_table = adnp_i2c_id,
};
module_i2c_driver(adnp_i2c_driver);
MODULE_DESCRIPTION("Avionic Design N-bit GPIO expander");
MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_LICENSE("GPL");