- 根目录:
- drivers
- gpio
- gpio-pca953x.c
/*
* PCA953x 4/8/16 bit I/O ports
*
* Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
* Copyright (C) 2007 Marvell International Ltd.
*
* Derived from drivers/i2c/chips/pca9539.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/i2c.h>
#include <linux/i2c/pca953x.h>
#include <linux/slab.h>
#ifdef CONFIG_OF_GPIO
#include <linux/of_platform.h>
#endif
#define PCA953X_INPUT 0
#define PCA953X_OUTPUT 1
#define PCA953X_INVERT 2
#define PCA953X_DIRECTION 3
#define PCA957X_IN 0
#define PCA957X_INVRT 1
#define PCA957X_BKEN 2
#define PCA957X_PUPD 3
#define PCA957X_CFG 4
#define PCA957X_OUT 5
#define PCA957X_MSK 6
#define PCA957X_INTS 7
#define PCA_GPIO_MASK 0x00FF
#define PCA_INT 0x0100
#define PCA953X_TYPE 0x1000
#define PCA957X_TYPE 0x2000
static const struct i2c_device_id pca953x_id[] = {
{ "pca9534", 8 | PCA953X_TYPE | PCA_INT, },
{ "pca9535", 16 | PCA953X_TYPE | PCA_INT, },
{ "pca9536", 4 | PCA953X_TYPE, },
{ "pca9537", 4 | PCA953X_TYPE | PCA_INT, },
{ "pca9538", 8 | PCA953X_TYPE | PCA_INT, },
{ "pca9539", 16 | PCA953X_TYPE | PCA_INT, },
{ "pca9554", 8 | PCA953X_TYPE | PCA_INT, },
{ "pca9555", 16 | PCA953X_TYPE | PCA_INT, },
{ "pca9556", 8 | PCA953X_TYPE, },
{ "pca9557", 8 | PCA953X_TYPE, },
{ "pca9574", 8 | PCA957X_TYPE | PCA_INT, },
{ "pca9575", 16 | PCA957X_TYPE | PCA_INT, },
{ "max7310", 8 | PCA953X_TYPE, },
{ "max7312", 16 | PCA953X_TYPE | PCA_INT, },
{ "max7313", 16 | PCA953X_TYPE | PCA_INT, },
{ "max7315", 8 | PCA953X_TYPE | PCA_INT, },
{ "pca6107", 8 | PCA953X_TYPE | PCA_INT, },
{ "tca6408", 8 | PCA953X_TYPE | PCA_INT, },
{ "tca6416", 16 | PCA953X_TYPE | PCA_INT, },
/* NYET: { "tca6424", 24, }, */
{ }
};
MODULE_DEVICE_TABLE(i2c, pca953x_id);
struct pca953x_chip {
unsigned gpio_start;
uint16_t reg_output;
uint16_t reg_direction;
struct mutex i2c_lock;
#ifdef CONFIG_GPIO_PCA953X_IRQ
struct mutex irq_lock;
uint16_t irq_mask;
uint16_t irq_stat;
uint16_t irq_trig_raise;
uint16_t irq_trig_fall;
int irq_base;
#endif
struct i2c_client *client;
struct gpio_chip gpio_chip;
const char *const *names;
int chip_type;
};
static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
{
int ret = 0;
if (chip->gpio_chip.ngpio <= 8)
ret = i2c_smbus_write_byte_data(chip->client, reg, val);
else {
switch (chip->chip_type) {
case PCA953X_TYPE:
ret = i2c_smbus_write_word_data(chip->client,
reg << 1, val);
break;
case PCA957X_TYPE:
ret = i2c_smbus_write_byte_data(chip->client, reg << 1,
val & 0xff);
if (ret < 0)
break;
ret = i2c_smbus_write_byte_data(chip->client,
(reg << 1) + 1,
(val & 0xff00) >> 8);
break;
}
}
if (ret < 0) {
dev_err(&chip->client->dev, "failed writing register\n");
return ret;
}
return 0;
}
static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val)
{
int ret;
if (chip->gpio_chip.ngpio <= 8)
ret = i2c_smbus_read_byte_data(chip->client, reg);
else
ret = i2c_smbus_read_word_data(chip->client, reg << 1);
if (ret < 0) {
dev_err(&chip->client->dev, "failed reading register\n");
return ret;
}
*val = (uint16_t)ret;
return 0;
}
static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
uint16_t reg_val;
int ret, offset = 0;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
mutex_lock(&chip->i2c_lock);
reg_val = chip->reg_direction | (1u << off);
switch (chip->chip_type) {
case PCA953X_TYPE:
offset = PCA953X_DIRECTION;
break;
case PCA957X_TYPE:
offset = PCA957X_CFG;
break;
}
ret = pca953x_write_reg(chip, offset, reg_val);
if (ret)
goto exit;
chip->reg_direction = reg_val;
ret = 0;
exit:
mutex_unlock(&chip->i2c_lock);
return ret;
}
static int pca953x_gpio_direction_output(struct gpio_chip *gc,
unsigned off, int val)
{
struct pca953x_chip *chip;
uint16_t reg_val;
int ret, offset = 0;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
mutex_lock(&chip->i2c_lock);
/* set output level */
if (val)
reg_val = chip->reg_output | (1u << off);
else
reg_val = chip->reg_output & ~(1u << off);
switch (chip->chip_type) {
case PCA953X_TYPE:
offset = PCA953X_OUTPUT;
break;
case PCA957X_TYPE:
offset = PCA957X_OUT;
break;
}
ret = pca953x_write_reg(chip, offset, reg_val);
if (ret)
goto exit;
chip->reg_output = reg_val;
/* then direction */
reg_val = chip->reg_direction & ~(1u << off);
switch (chip->chip_type) {
case PCA953X_TYPE:
offset = PCA953X_DIRECTION;
break;
case PCA957X_TYPE:
offset = PCA957X_CFG;
break;
}
ret = pca953x_write_reg(chip, offset, reg_val);
if (ret)
goto exit;
chip->reg_direction = reg_val;
ret = 0;
exit:
mutex_unlock(&chip->i2c_lock);
return ret;
}
static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
uint16_t reg_val;
int ret, offset = 0;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
mutex_lock(&chip->i2c_lock);
switch (chip->chip_type) {
case PCA953X_TYPE:
offset = PCA953X_INPUT;
break;
case PCA957X_TYPE:
offset = PCA957X_IN;
break;
}
ret = pca953x_read_reg(chip, offset, ®_val);
mutex_unlock(&chip->i2c_lock);
if (ret < 0) {
/* NOTE: diagnostic already emitted; that's all we should
* do unless gpio_*_value_cansleep() calls become different
* from their nonsleeping siblings (and report faults).
*/
return 0;
}
return (reg_val & (1u << off)) ? 1 : 0;
}
static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
struct pca953x_chip *chip;
uint16_t reg_val;
int ret, offset = 0;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
mutex_lock(&chip->i2c_lock);
if (val)
reg_val = chip->reg_output | (1u << off);
else
reg_val = chip->reg_output & ~(1u << off);
switch (chip->chip_type) {
case PCA953X_TYPE:
offset = PCA953X_OUTPUT;
break;
case PCA957X_TYPE:
offset = PCA957X_OUT;
break;
}
ret = pca953x_write_reg(chip, offset, reg_val);
if (ret)
goto exit;
chip->reg_output = reg_val;
exit:
mutex_unlock(&chip->i2c_lock);
}
static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
{
struct gpio_chip *gc;
gc = &chip->gpio_chip;
gc->direction_input = pca953x_gpio_direction_input;
gc->direction_output = pca953x_gpio_direction_output;
gc->get = pca953x_gpio_get_value;
gc->set = pca953x_gpio_set_value;
gc->can_sleep = 1;
gc->base = chip->gpio_start;
gc->ngpio = gpios;
gc->label = chip->client->name;
gc->dev = &chip->client->dev;
gc->owner = THIS_MODULE;
gc->names = chip->names;
}
#ifdef CONFIG_GPIO_PCA953X_IRQ
static int pca953x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
{
struct pca953x_chip *chip;
chip = container_of(gc, struct pca953x_chip, gpio_chip);
return chip->irq_base + off;
}
static void pca953x_irq_mask(struct irq_data *d)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
chip->irq_mask &= ~(1 << (d->irq - chip->irq_base));
}
static void pca953x_irq_unmask(struct irq_data *d)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
chip->irq_mask |= 1 << (d->irq - chip->irq_base);
}
static void pca953x_irq_bus_lock(struct irq_data *d)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
mutex_lock(&chip->irq_lock);
}
static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
uint16_t new_irqs;
uint16_t level;
/* Look for any newly setup interrupt */
new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
new_irqs &= ~chip->reg_direction;
while (new_irqs) {
level = __ffs(new_irqs);
pca953x_gpio_direction_input(&chip->gpio_chip, level);
new_irqs &= ~(1 << level);
}
mutex_unlock(&chip->irq_lock);
}
static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
{
struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
uint16_t level = d->irq - chip->irq_base;
uint16_t mask = 1 << level;
if (!(type & IRQ_TYPE_EDGE_BOTH)) {
dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
d->irq, type);
return -EINVAL;
}
if (type & IRQ_TYPE_EDGE_FALLING)
chip->irq_trig_fall |= mask;
else
chip->irq_trig_fall &= ~mask;
if (type & IRQ_TYPE_EDGE_RISING)
chip->irq_trig_raise |= mask;
else
chip->irq_trig_raise &= ~mask;
return 0;
}
static struct irq_chip pca953x_irq_chip = {
.name = "pca953x",
.irq_mask = pca953x_irq_mask,
.irq_unmask = pca953x_irq_unmask,
.irq_bus_lock = pca953x_irq_bus_lock,
.irq_bus_sync_unlock = pca953x_irq_bus_sync_unlock,
.irq_set_type = pca953x_irq_set_type,
};
static uint16_t pca953x_irq_pending(struct pca953x_chip *chip)
{
uint16_t cur_stat;
uint16_t old_stat;
uint16_t pending;
uint16_t trigger;
int ret, offset = 0;
switch (chip->chip_type) {
case PCA953X_TYPE:
offset = PCA953X_INPUT;
break;
case PCA957X_TYPE:
offset = PCA957X_IN;
break;
}
ret = pca953x_read_reg(chip, offset, &cur_stat);
if (ret)
return 0;
/* Remove output pins from the equation */
cur_stat &= chip->reg_direction;
old_stat = chip->irq_stat;
trigger = (cur_stat ^ old_stat) & chip->irq_mask;
if (!trigger)
return 0;
chip->irq_stat = cur_stat;
pending = (old_stat & chip->irq_trig_fall) |
(cur_stat & chip->irq_trig_raise);
pending &= trigger;
return pending;
}
static irqreturn_t pca953x_irq_handler(int irq, void *devid)
{
struct pca953x_chip *chip = devid;
uint16_t pending;
uint16_t level;
pending = pca953x_irq_pending(chip);
if (!pending)
return IRQ_HANDLED;
do {
level = __ffs(pending);
handle_nested_irq(level + chip->irq_base);
pending &= ~(1 << level);
} while (pending);
return IRQ_HANDLED;
}
static int pca953x_irq_setup(struct pca953x_chip *chip,
const struct i2c_device_id *id,
int irq_base)
{
struct i2c_client *client = chip->client;
int ret, offset = 0;
if (irq_base != -1
&& (id->driver_data & PCA_INT)) {
int lvl;
switch (chip->chip_type) {
case PCA953X_TYPE:
offset = PCA953X_INPUT;
break;
case PCA957X_TYPE:
offset = PCA957X_IN;
break;
}
ret = pca953x_read_reg(chip, offset, &chip->irq_stat);
if (ret)
goto out_failed;
/*
* There is no way to know which GPIO line generated the
* interrupt. We have to rely on the previous read for
* this purpose.
*/
chip->irq_stat &= chip->reg_direction;
mutex_init(&chip->irq_lock);
chip->irq_base = irq_alloc_descs(-1, irq_base, chip->gpio_chip.ngpio, -1);
if (chip->irq_base < 0)
goto out_failed;
for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
int irq = lvl + chip->irq_base;
irq_clear_status_flags(irq, IRQ_NOREQUEST);
irq_set_chip_data(irq, chip);
irq_set_chip(irq, &pca953x_irq_chip);
irq_set_nested_thread(irq, true);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
irq_set_noprobe(irq);
#endif
}
ret = request_threaded_irq(client->irq,
NULL,
pca953x_irq_handler,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
dev_name(&client->dev), chip);
if (ret) {
dev_err(&client->dev, "failed to request irq %d\n",
client->irq);
goto out_failed;
}
chip->gpio_chip.to_irq = pca953x_gpio_to_irq;
}
return 0;
out_failed:
chip->irq_base = -1;
return ret;
}
static void pca953x_irq_teardown(struct pca953x_chip *chip)
{
if (chip->irq_base != -1) {
irq_free_descs(chip->irq_base, chip->gpio_chip.ngpio);
free_irq(chip->client->irq, chip);
}
}
#else /* CONFIG_GPIO_PCA953X_IRQ */
static int pca953x_irq_setup(struct pca953x_chip *chip,
const struct i2c_device_id *id,
int irq_base)
{
struct i2c_client *client = chip->client;
if (irq_base != -1 && (id->driver_data & PCA_INT))
dev_warn(&client->dev, "interrupt support not compiled in\n");
return 0;
}
static void pca953x_irq_teardown(struct pca953x_chip *chip)
{
}
#endif
/*
* Handlers for alternative sources of platform_data
*/
#ifdef CONFIG_OF_GPIO
/*
* Translate OpenFirmware node properties into platform_data
* WARNING: This is DEPRECATED and will be removed eventually!
*/
static void
pca953x_get_alt_pdata(struct i2c_client *client, int *gpio_base, int *invert)
{
struct device_node *node;
const __be32 *val;
int size;
node = client->dev.of_node;
if (node == NULL)
return;
*gpio_base = -1;
val = of_get_property(node, "linux,gpio-base", &size);
WARN(val, "%s: device-tree property 'linux,gpio-base' is deprecated!", __func__);
if (val) {
if (size != sizeof(*val))
dev_warn(&client->dev, "%s: wrong linux,gpio-base\n",
node->full_name);
else
*gpio_base = be32_to_cpup(val);
}
val = of_get_property(node, "polarity", NULL);
WARN(val, "%s: device-tree property 'polarity' is deprecated!", __func__);
if (val)
*invert = *val;
}
#else
static void
pca953x_get_alt_pdata(struct i2c_client *client, int *gpio_base, int *invert)
{
*gpio_base = -1;
}
#endif
static int __devinit device_pca953x_init(struct pca953x_chip *chip, int invert)
{
int ret;
ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
if (ret)
goto out;
ret = pca953x_read_reg(chip, PCA953X_DIRECTION,
&chip->reg_direction);
if (ret)
goto out;
/* set platform specific polarity inversion */
ret = pca953x_write_reg(chip, PCA953X_INVERT, invert);
out:
return ret;
}
static int __devinit device_pca957x_init(struct pca953x_chip *chip, int invert)
{
int ret;
uint16_t val = 0;
/* Let every port in proper state, that could save power */
pca953x_write_reg(chip, PCA957X_PUPD, 0x0);
pca953x_write_reg(chip, PCA957X_CFG, 0xffff);
pca953x_write_reg(chip, PCA957X_OUT, 0x0);
ret = pca953x_read_reg(chip, PCA957X_IN, &val);
if (ret)
goto out;
ret = pca953x_read_reg(chip, PCA957X_OUT, &chip->reg_output);
if (ret)
goto out;
ret = pca953x_read_reg(chip, PCA957X_CFG, &chip->reg_direction);
if (ret)
goto out;
/* set platform specific polarity inversion */
pca953x_write_reg(chip, PCA957X_INVRT, invert);
/* To enable register 6, 7 to controll pull up and pull down */
pca953x_write_reg(chip, PCA957X_BKEN, 0x202);
return 0;
out:
return ret;
}
static int __devinit pca953x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pca953x_platform_data *pdata;
struct pca953x_chip *chip;
int irq_base=0, invert=0;
int ret;
chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
if (chip == NULL)
return -ENOMEM;
pdata = client->dev.platform_data;
if (pdata) {
irq_base = pdata->irq_base;
chip->gpio_start = pdata->gpio_base;
invert = pdata->invert;
chip->names = pdata->names;
} else {
pca953x_get_alt_pdata(client, &chip->gpio_start, &invert);
#ifdef CONFIG_OF_GPIO
/* If I2C node has no interrupts property, disable GPIO interrupts */
if (of_find_property(client->dev.of_node, "interrupts", NULL) == NULL)
irq_base = -1;
#endif
}
chip->client = client;
chip->chip_type = id->driver_data & (PCA953X_TYPE | PCA957X_TYPE);
mutex_init(&chip->i2c_lock);
/* initialize cached registers from their original values.
* we can't share this chip with another i2c master.
*/
pca953x_setup_gpio(chip, id->driver_data & PCA_GPIO_MASK);
if (chip->chip_type == PCA953X_TYPE)
ret = device_pca953x_init(chip, invert);
else
ret = device_pca957x_init(chip, invert);
if (ret)
goto out_failed;
ret = pca953x_irq_setup(chip, id, irq_base);
if (ret)
goto out_failed;
ret = gpiochip_add(&chip->gpio_chip);
if (ret)
goto out_failed_irq;
if (pdata && pdata->setup) {
ret = pdata->setup(client, chip->gpio_chip.base,
chip->gpio_chip.ngpio, pdata->context);
if (ret < 0)
dev_warn(&client->dev, "setup failed, %d\n", ret);
}
i2c_set_clientdata(client, chip);
return 0;
out_failed_irq:
pca953x_irq_teardown(chip);
out_failed:
kfree(chip);
return ret;
}
static int pca953x_remove(struct i2c_client *client)
{
struct pca953x_platform_data *pdata = client->dev.platform_data;
struct pca953x_chip *chip = i2c_get_clientdata(client);
int ret = 0;
if (pdata && pdata->teardown) {
ret = pdata->teardown(client, chip->gpio_chip.base,
chip->gpio_chip.ngpio, pdata->context);
if (ret < 0) {
dev_err(&client->dev, "%s failed, %d\n",
"teardown", ret);
return ret;
}
}
ret = gpiochip_remove(&chip->gpio_chip);
if (ret) {
dev_err(&client->dev, "%s failed, %d\n",
"gpiochip_remove()", ret);
return ret;
}
pca953x_irq_teardown(chip);
kfree(chip);
return 0;
}
static struct i2c_driver pca953x_driver = {
.driver = {
.name = "pca953x",
},
.probe = pca953x_probe,
.remove = pca953x_remove,
.id_table = pca953x_id,
};
static int __init pca953x_init(void)
{
return i2c_add_driver(&pca953x_driver);
}
/* register after i2c postcore initcall and before
* subsys initcalls that may rely on these GPIOs
*/
subsys_initcall(pca953x_init);
static void __exit pca953x_exit(void)
{
i2c_del_driver(&pca953x_driver);
}
module_exit(pca953x_exit);
MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
MODULE_LICENSE("GPL");