Commit 5e969a40 authored by Thierry Reding's avatar Thierry Reding Committed by Linus Walleij

gpio: Add Avionic Design N-bit GPIO expander support

This commit adds a driver for the Avionic Design N-bit GPIO expander.
The expander provides a variable number of GPIO pins with interrupt
support.

Changes in v2:
- allow building the driver as a module
- assign of_node unconditionally
- use linear mapping IRQ domain
- properly cleanup IRQ domain
- add OF device table and annotate device tables
- emulate rising and falling edge triggers
- increase #gpio-cells to 2
- drop support for !OF
- use IS_ENABLED to conditionalize DEBUG_FS code

Changes in v3:
- make IRQ support runtime configurable (interrupt-controller property)
- drop interrupt-controller and #interrupt-cells from DT binding
- add inline to_adnp() function to wrap container_of() macro
- consistently use adnp as name for struct adnp variables
- remove irq_mask_cur and rename irq_mask to irq_enable
- fix a subtle deadlock in adnp_gpio_direction_output()
- remove dynamic allocations from debugfs code
- rename regs to num_regs to avoid confusion
- annotate non-trivial code with comments
- don't acquire mutex in adnp_gpio_get()
- assume NO_IRQ == 0

Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: linux-kernel@vger.kernel.org
Acked-by: default avatarRob Herring <rob.herring@calxeda.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent d724f1c9
Avionic Design N-bit GPIO expander bindings
Required properties:
- compatible: should be "ad,gpio-adnp"
- reg: The I2C slave address for this device.
- interrupt-parent: phandle of the parent interrupt controller.
- interrupts: Interrupt specifier for the controllers interrupt.
- #gpio-cells: Should be 2. The first cell is the GPIO number and the
second cell is used to specify optional parameters:
- bit 0: polarity (0: normal, 1: inverted)
- gpio-controller: Marks the device as a GPIO controller
- nr-gpios: The number of pins supported by the controller.
Example:
gpioext: gpio-controller@41 {
compatible = "ad,gpio-adnp";
reg = <0x41>;
interrupt-parent = <&gpio>;
interrupts = <160 1>;
gpio-controller;
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
nr-gpios = <64>;
};
...@@ -444,6 +444,17 @@ config GPIO_ADP5588_IRQ ...@@ -444,6 +444,17 @@ config GPIO_ADP5588_IRQ
Say yes here to enable the adp5588 to be used as an interrupt Say yes here to enable the adp5588 to be used as an interrupt
controller. It requires the driver to be built in the kernel. controller. It requires the driver to be built in the kernel.
config GPIO_ADNP
tristate "Avionic Design N-bit GPIO expander"
depends on I2C && OF
help
This option enables support for N GPIOs found on Avionic Design
I2C GPIO expanders. The register space will be extended by powers
of two, so the controller will need to accomodate for that. For
example: if a controller provides 48 pins, 6 registers will be
enough to represent all pins, but the driver will assume a
register layout for 64 pins (8 registers).
comment "PCI GPIO expanders:" comment "PCI GPIO expanders:"
config GPIO_CS5535 config GPIO_CS5535
......
...@@ -10,6 +10,7 @@ obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o ...@@ -10,6 +10,7 @@ obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o
obj-$(CONFIG_GPIO_74X164) += gpio-74x164.o obj-$(CONFIG_GPIO_74X164) += gpio-74x164.o
obj-$(CONFIG_GPIO_AB8500) += gpio-ab8500.o obj-$(CONFIG_GPIO_AB8500) += gpio-ab8500.o
obj-$(CONFIG_GPIO_ADNP) += gpio-adnp.o
obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o
obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o
obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o
......
/*
* 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.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.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 irq_domain *domain;
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;
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 = 1;
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;
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 virq;
virq = irq_find_mapping(adnp->domain, base + bit);
handle_nested_irq(virq);
}
}
return IRQ_HANDLED;
}
static int adnp_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct adnp *adnp = to_adnp(chip);
return irq_create_mapping(adnp->domain, offset);
}
static void adnp_irq_mask(struct irq_data *data)
{
struct adnp *adnp = irq_data_get_irq_chip_data(data);
unsigned int reg = data->hwirq >> adnp->reg_shift;
unsigned int pos = data->hwirq & 7;
adnp->irq_enable[reg] &= ~BIT(pos);
}
static void adnp_irq_unmask(struct irq_data *data)
{
struct adnp *adnp = irq_data_get_irq_chip_data(data);
unsigned int reg = data->hwirq >> adnp->reg_shift;
unsigned int pos = data->hwirq & 7;
adnp->irq_enable[reg] |= BIT(pos);
}
static int adnp_irq_set_type(struct irq_data *data, unsigned int type)
{
struct adnp *adnp = irq_data_get_irq_chip_data(data);
unsigned int reg = data->hwirq >> adnp->reg_shift;
unsigned int pos = data->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 *data)
{
struct adnp *adnp = irq_data_get_irq_chip_data(data);
mutex_lock(&adnp->irq_lock);
}
static void adnp_irq_bus_unlock(struct irq_data *data)
{
struct adnp *adnp = irq_data_get_irq_chip_data(data);
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_map(struct irq_domain *domain, unsigned int irq,
irq_hw_number_t hwirq)
{
irq_set_chip_data(irq, domain->host_data);
irq_set_chip(irq, &adnp_irq_chip);
irq_set_nested_thread(irq, true);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
irq_set_noprobe(irq);
#endif
return 0;
}
static const struct irq_domain_ops adnp_irq_domain_ops = {
.map = adnp_irq_map,
.xlate = irq_domain_xlate_twocell,
};
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;
}
adnp->domain = irq_domain_add_linear(chip->of_node, chip->ngpio,
&adnp_irq_domain_ops, adnp);
err = request_threaded_irq(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);
goto error;
}
chip->to_irq = adnp_gpio_to_irq;
return 0;
error:
irq_domain_remove(adnp->domain);
return err;
}
static void adnp_irq_teardown(struct adnp *adnp)
{
unsigned int irq, i;
free_irq(adnp->client->irq, adnp);
for (i = 0; i < adnp->gpio.ngpio; i++) {
irq = irq_find_mapping(adnp->domain, i);
if (irq > 0)
irq_dispose_mapping(irq);
}
irq_domain_remove(adnp->domain);
}
static __devinit 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 < 0)
return err;
if (of_find_property(np, "interrupt-controller", NULL)) {
err = adnp_irq_setup(adnp);
if (err < 0)
goto teardown;
}
err = gpiochip_add(&adnp->gpio);
if (err < 0)
goto teardown;
i2c_set_clientdata(client, adnp);
return 0;
teardown:
if (of_find_property(np, "interrupt-controller", NULL))
adnp_irq_teardown(adnp);
return err;
}
static __devexit int adnp_i2c_remove(struct i2c_client *client)
{
struct adnp *adnp = i2c_get_clientdata(client);
struct device_node *np = client->dev.of_node;
int err;
err = gpiochip_remove(&adnp->gpio);
if (err < 0) {
dev_err(&client->dev, "%s failed: %d\n", "gpiochip_remove()",
err);
return err;
}
if (of_find_property(np, "interrupt-controller", NULL))
adnp_irq_teardown(adnp);
return 0;
}
static const struct i2c_device_id adnp_i2c_id[] __devinitconst = {
{ "gpio-adnp" },
{ },
};
MODULE_DEVICE_TABLE(i2c, adnp_i2c_id);
static const struct of_device_id adnp_of_match[] __devinitconst = {
{ .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 = of_match_ptr(adnp_of_match),
},
.probe = adnp_i2c_probe,
.remove = __devexit_p(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");
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