summaryrefslogtreecommitdiff
path: root/drivers/gpio/pcf857x.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/gpio/pcf857x.c')
-rw-r--r--drivers/gpio/pcf857x.c369
1 files changed, 0 insertions, 369 deletions
diff --git a/drivers/gpio/pcf857x.c b/drivers/gpio/pcf857x.c
deleted file mode 100644
index 879b473aab5a..000000000000
--- a/drivers/gpio/pcf857x.c
+++ /dev/null
@@ -1,369 +0,0 @@
-/*
- * pcf857x - driver for pcf857x, pca857x, and pca967x I2C GPIO expanders
- *
- * Copyright (C) 2007 David Brownell
- *
- * 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; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/gpio.h>
-#include <linux/i2c.h>
-#include <linux/i2c/pcf857x.h>
-
-
-static const struct i2c_device_id pcf857x_id[] = {
- { "pcf8574", 8 },
- { "pcf8574a", 8 },
- { "pca8574", 8 },
- { "pca9670", 8 },
- { "pca9672", 8 },
- { "pca9674", 8 },
- { "pcf8575", 16 },
- { "pca8575", 16 },
- { "pca9671", 16 },
- { "pca9673", 16 },
- { "pca9675", 16 },
- { "max7328", 8 },
- { "max7329", 8 },
- { }
-};
-MODULE_DEVICE_TABLE(i2c, pcf857x_id);
-
-/*
- * The pcf857x, pca857x, and pca967x chips only expose one read and one
- * write register. Writing a "one" bit (to match the reset state) lets
- * that pin be used as an input; it's not an open-drain model, but acts
- * a bit like one. This is described as "quasi-bidirectional"; read the
- * chip documentation for details.
- *
- * Many other I2C GPIO expander chips (like the pca953x models) have
- * more complex register models and more conventional circuitry using
- * push/pull drivers. They often use the same 0x20..0x27 addresses as
- * pcf857x parts, making the "legacy" I2C driver model problematic.
- */
-struct pcf857x {
- struct gpio_chip chip;
- struct i2c_client *client;
- struct mutex lock; /* protect 'out' */
- unsigned out; /* software latch */
-};
-
-/*-------------------------------------------------------------------------*/
-
-/* Talk to 8-bit I/O expander */
-
-static int pcf857x_input8(struct gpio_chip *chip, unsigned offset)
-{
- struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
- int status;
-
- mutex_lock(&gpio->lock);
- gpio->out |= (1 << offset);
- status = i2c_smbus_write_byte(gpio->client, gpio->out);
- mutex_unlock(&gpio->lock);
-
- return status;
-}
-
-static int pcf857x_get8(struct gpio_chip *chip, unsigned offset)
-{
- struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
- s32 value;
-
- value = i2c_smbus_read_byte(gpio->client);
- return (value < 0) ? 0 : (value & (1 << offset));
-}
-
-static int pcf857x_output8(struct gpio_chip *chip, unsigned offset, int value)
-{
- struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
- unsigned bit = 1 << offset;
- int status;
-
- mutex_lock(&gpio->lock);
- if (value)
- gpio->out |= bit;
- else
- gpio->out &= ~bit;
- status = i2c_smbus_write_byte(gpio->client, gpio->out);
- mutex_unlock(&gpio->lock);
-
- return status;
-}
-
-static void pcf857x_set8(struct gpio_chip *chip, unsigned offset, int value)
-{
- pcf857x_output8(chip, offset, value);
-}
-
-/*-------------------------------------------------------------------------*/
-
-/* Talk to 16-bit I/O expander */
-
-static int i2c_write_le16(struct i2c_client *client, u16 word)
-{
- u8 buf[2] = { word & 0xff, word >> 8, };
- int status;
-
- status = i2c_master_send(client, buf, 2);
- return (status < 0) ? status : 0;
-}
-
-static int i2c_read_le16(struct i2c_client *client)
-{
- u8 buf[2];
- int status;
-
- status = i2c_master_recv(client, buf, 2);
- if (status < 0)
- return status;
- return (buf[1] << 8) | buf[0];
-}
-
-static int pcf857x_input16(struct gpio_chip *chip, unsigned offset)
-{
- struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
- int status;
-
- mutex_lock(&gpio->lock);
- gpio->out |= (1 << offset);
- status = i2c_write_le16(gpio->client, gpio->out);
- mutex_unlock(&gpio->lock);
-
- return status;
-}
-
-static int pcf857x_get16(struct gpio_chip *chip, unsigned offset)
-{
- struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
- int value;
-
- value = i2c_read_le16(gpio->client);
- return (value < 0) ? 0 : (value & (1 << offset));
-}
-
-static int pcf857x_output16(struct gpio_chip *chip, unsigned offset, int value)
-{
- struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
- unsigned bit = 1 << offset;
- int status;
-
- mutex_lock(&gpio->lock);
- if (value)
- gpio->out |= bit;
- else
- gpio->out &= ~bit;
- status = i2c_write_le16(gpio->client, gpio->out);
- mutex_unlock(&gpio->lock);
-
- return status;
-}
-
-static void pcf857x_set16(struct gpio_chip *chip, unsigned offset, int value)
-{
- pcf857x_output16(chip, offset, value);
-}
-
-/*-------------------------------------------------------------------------*/
-
-static int pcf857x_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
-{
- struct pcf857x_platform_data *pdata;
- struct pcf857x *gpio;
- int status;
-
- pdata = client->dev.platform_data;
- if (!pdata) {
- dev_dbg(&client->dev, "no platform data\n");
- }
-
- /* Allocate, initialize, and register this gpio_chip. */
- gpio = kzalloc(sizeof *gpio, GFP_KERNEL);
- if (!gpio)
- return -ENOMEM;
-
- mutex_init(&gpio->lock);
-
- gpio->chip.base = pdata ? pdata->gpio_base : -1;
- gpio->chip.can_sleep = 1;
- gpio->chip.dev = &client->dev;
- gpio->chip.owner = THIS_MODULE;
-
- /* NOTE: the OnSemi jlc1562b is also largely compatible with
- * these parts, notably for output. It has a low-resolution
- * DAC instead of pin change IRQs; and its inputs can be the
- * result of comparators.
- */
-
- /* 8574 addresses are 0x20..0x27; 8574a uses 0x38..0x3f;
- * 9670, 9672, 9764, and 9764a use quite a variety.
- *
- * NOTE: we don't distinguish here between *4 and *4a parts.
- */
- gpio->chip.ngpio = id->driver_data;
- if (gpio->chip.ngpio == 8) {
- gpio->chip.direction_input = pcf857x_input8;
- gpio->chip.get = pcf857x_get8;
- gpio->chip.direction_output = pcf857x_output8;
- gpio->chip.set = pcf857x_set8;
-
- if (!i2c_check_functionality(client->adapter,
- I2C_FUNC_SMBUS_BYTE))
- status = -EIO;
-
- /* fail if there's no chip present */
- else
- status = i2c_smbus_read_byte(client);
-
- /* '75/'75c addresses are 0x20..0x27, just like the '74;
- * the '75c doesn't have a current source pulling high.
- * 9671, 9673, and 9765 use quite a variety of addresses.
- *
- * NOTE: we don't distinguish here between '75 and '75c parts.
- */
- } else if (gpio->chip.ngpio == 16) {
- gpio->chip.direction_input = pcf857x_input16;
- gpio->chip.get = pcf857x_get16;
- gpio->chip.direction_output = pcf857x_output16;
- gpio->chip.set = pcf857x_set16;
-
- if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
- status = -EIO;
-
- /* fail if there's no chip present */
- else
- status = i2c_read_le16(client);
-
- } else {
- dev_dbg(&client->dev, "unsupported number of gpios\n");
- status = -EINVAL;
- }
-
- if (status < 0)
- goto fail;
-
- gpio->chip.label = client->name;
-
- gpio->client = client;
- i2c_set_clientdata(client, gpio);
-
- /* NOTE: these chips have strange "quasi-bidirectional" I/O pins.
- * We can't actually know whether a pin is configured (a) as output
- * and driving the signal low, or (b) as input and reporting a low
- * value ... without knowing the last value written since the chip
- * came out of reset (if any). We can't read the latched output.
- *
- * In short, the only reliable solution for setting up pin direction
- * is to do it explicitly. The setup() method can do that, but it
- * may cause transient glitching since it can't know the last value
- * written (some pins may need to be driven low).
- *
- * Using pdata->n_latch avoids that trouble. When left initialized
- * to zero, our software copy of the "latch" then matches the chip's
- * all-ones reset state. Otherwise it flags pins to be driven low.
- */
- gpio->out = pdata ? ~pdata->n_latch : ~0;
-
- status = gpiochip_add(&gpio->chip);
- if (status < 0)
- goto fail;
-
- /* NOTE: these chips can issue "some pin-changed" IRQs, which we
- * don't yet even try to use. Among other issues, the relevant
- * genirq state isn't available to modular drivers; and most irq
- * methods can't be called from sleeping contexts.
- */
-
- dev_info(&client->dev, "gpios %d..%d on a %s%s\n",
- gpio->chip.base,
- gpio->chip.base + gpio->chip.ngpio - 1,
- client->name,
- client->irq ? " (irq ignored)" : "");
-
- /* Let platform code set up the GPIOs and their users.
- * Now is the first time anyone could use them.
- */
- if (pdata && pdata->setup) {
- status = pdata->setup(client,
- gpio->chip.base, gpio->chip.ngpio,
- pdata->context);
- if (status < 0)
- dev_warn(&client->dev, "setup --> %d\n", status);
- }
-
- return 0;
-
-fail:
- dev_dbg(&client->dev, "probe error %d for '%s'\n",
- status, client->name);
- kfree(gpio);
- return status;
-}
-
-static int pcf857x_remove(struct i2c_client *client)
-{
- struct pcf857x_platform_data *pdata = client->dev.platform_data;
- struct pcf857x *gpio = i2c_get_clientdata(client);
- int status = 0;
-
- if (pdata && pdata->teardown) {
- status = pdata->teardown(client,
- gpio->chip.base, gpio->chip.ngpio,
- pdata->context);
- if (status < 0) {
- dev_err(&client->dev, "%s --> %d\n",
- "teardown", status);
- return status;
- }
- }
-
- status = gpiochip_remove(&gpio->chip);
- if (status == 0)
- kfree(gpio);
- else
- dev_err(&client->dev, "%s --> %d\n", "remove", status);
- return status;
-}
-
-static struct i2c_driver pcf857x_driver = {
- .driver = {
- .name = "pcf857x",
- .owner = THIS_MODULE,
- },
- .probe = pcf857x_probe,
- .remove = pcf857x_remove,
- .id_table = pcf857x_id,
-};
-
-static int __init pcf857x_init(void)
-{
- return i2c_add_driver(&pcf857x_driver);
-}
-/* register after i2c postcore initcall and before
- * subsys initcalls that may rely on these GPIOs
- */
-subsys_initcall(pcf857x_init);
-
-static void __exit pcf857x_exit(void)
-{
- i2c_del_driver(&pcf857x_driver);
-}
-module_exit(pcf857x_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("David Brownell");