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gpio: add driver for MAX7300 I2C GPIO extender

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Add the MAX7300-I2C variant of the MAX7301-SPI version.  Both chips share
the same core logic, so the generic part of the in-kernel SPI-driver is
refactored into a generic part.  The I2C and SPI specific funtions are
then wrapped into seperate drivers picking up the generic part.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Juergen Beisert <j.beisert@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Wolfram Sang 2010-03-05 13:44:33 -08:00 committed by Linus Torvalds
parent 5a98c04d78
commit e952805d2d
6 changed files with 404 additions and 260 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/gpio/Kconfig
View File

@ -65,6 +65,9 @@ config GPIO_SYSFS
# put expanders in the right section, in alphabetical order
config GPIO_MAX730X
tristate
comment "Memory mapped GPIO expanders:"
config GPIO_PL061
@ -87,6 +90,13 @@ config GPIO_VR41XX
comment "I2C GPIO expanders:"
config GPIO_MAX7300
tristate "Maxim MAX7300 GPIO expander"
depends on I2C
select GPIO_MAX730X
help
GPIO driver for Maxim MAX7301 I2C-based GPIO expander.
config GPIO_MAX732X
tristate "MAX7319, MAX7320-7327 I2C Port Expanders"
depends on I2C
@ -226,8 +236,9 @@ comment "SPI GPIO expanders:"
config GPIO_MAX7301
tristate "Maxim MAX7301 GPIO expander"
depends on SPI_MASTER
select GPIO_MAX730X
help
gpio driver for Maxim MAX7301 SPI GPIO expander.
GPIO driver for Maxim MAX7301 SPI-based GPIO expander.
config GPIO_MCP23S08
tristate "Microchip MCP23S08 I/O expander"

2
drivers/gpio/Makefile
View File

@ -7,6 +7,8 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o
obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o
obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o
obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o
obj-$(CONFIG_GPIO_MAX730X) += max730x.o
obj-$(CONFIG_GPIO_MAX7300) += max7300.o
obj-$(CONFIG_GPIO_MAX7301) += max7301.o
obj-$(CONFIG_GPIO_MAX732X) += max732x.o
obj-$(CONFIG_GPIO_MC33880) += mc33880.o

94
drivers/gpio/max7300.c Normal file
View File

@ -0,0 +1,94 @@
/*
* drivers/gpio/max7300.c
*
* Copyright (C) 2009 Wolfram Sang, Pengutronix
*
* 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.
*
* Check max730x.c for further details.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/i2c.h>
#include <linux/spi/max7301.h>
static int max7300_i2c_write(struct device *dev, unsigned int reg,
unsigned int val)
{
struct i2c_client *client = to_i2c_client(dev);
return i2c_smbus_write_byte_data(client, reg, val);
}
static int max7300_i2c_read(struct device *dev, unsigned int reg)
{
struct i2c_client *client = to_i2c_client(dev);
return i2c_smbus_read_byte_data(client, reg);
}
static int __devinit max7300_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct max7301 *ts;
int ret;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_BYTE_DATA))
return -EIO;
ts = kzalloc(sizeof(struct max7301), GFP_KERNEL);
if (!ts)
return -ENOMEM;
ts->read = max7300_i2c_read;
ts->write = max7300_i2c_write;
ts->dev = &client->dev;
ret = __max730x_probe(ts);
if (ret)
kfree(ts);
return ret;
}
static int __devexit max7300_remove(struct i2c_client *client)
{
return __max730x_remove(&client->dev);
}
static const struct i2c_device_id max7300_id[] = {
{ "max7300", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, max7300_id);
static struct i2c_driver max7300_driver = {
.driver = {
.name = "max7300",
.owner = THIS_MODULE,
},
.probe = max7300_probe,
.remove = __devexit_p(max7300_remove),
.id_table = max7300_id,
};
static int __init max7300_init(void)
{
return i2c_add_driver(&max7300_driver);
}
subsys_initcall(max7300_init);
static void __exit max7300_exit(void)
{
i2c_del_driver(&max7300_driver);
}
module_exit(max7300_exit);
MODULE_AUTHOR("Wolfram Sang");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MAX7300 GPIO-Expander");

293
drivers/gpio/max7301.c
View File

@ -1,98 +1,41 @@
/**
/*
* drivers/gpio/max7301.c
*
* Copyright (C) 2006 Juergen Beisert, Pengutronix
* Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix
* Copyright (C) 2009 Wolfram Sang, Pengutronix
*
* 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.
*
* The Maxim's MAX7301 device is an SPI driven GPIO expander. There are
* 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more
* details
* Note:
* - DIN must be stable at the rising edge of clock.
* - when writing:
* - always clock in 16 clocks at once
* - at DIN: D15 first, D0 last
* - D0..D7 = databyte, D8..D14 = commandbyte
* - D15 = low -> write command
* - when reading
* - always clock in 16 clocks at once
* - at DIN: D15 first, D0 last
* - D0..D7 = dummy, D8..D14 = register address
* - D15 = high -> read command
* - raise CS and assert it again
* - always clock in 16 clocks at once
* - at DOUT: D15 first, D0 last
* - D0..D7 contains the data from the first cycle
*
* The driver exports a standard gpiochip interface
* Check max730x.c for further details.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/spi/spi.h>
#include <linux/spi/max7301.h>
#include <linux/gpio.h>
#define DRIVER_NAME "max7301"
/*
* Pin configurations, see MAX7301 datasheet page 6
*/
#define PIN_CONFIG_MASK 0x03
#define PIN_CONFIG_IN_PULLUP 0x03
#define PIN_CONFIG_IN_WO_PULLUP 0x02
#define PIN_CONFIG_OUT 0x01
#define PIN_NUMBER 28
/*
* Some registers must be read back to modify.
* To save time we cache them here in memory
*/
struct max7301 {
struct mutex lock;
u8 port_config[8]; /* field 0 is unused */
u32 out_level; /* cached output levels */
struct gpio_chip chip;
struct spi_device *spi;
};
/**
* max7301_write - Write a new register content
* @spi: The SPI device
* @reg: Register offset
* @val: Value to write
*
* A write to the MAX7301 means one message with one transfer
*
* Returns 0 if successful or a negative value on error
*/
static int max7301_write(struct spi_device *spi, unsigned int reg, unsigned int val)
/* A write to the MAX7301 means one message with one transfer */
static int max7301_spi_write(struct device *dev, unsigned int reg,
unsigned int val)
{
struct spi_device *spi = to_spi_device(dev);
u16 word = ((reg & 0x7F) << 8) | (val & 0xFF);
return spi_write(spi, (const u8 *)&word, sizeof(word));
}
/**
* max7301_read - Read back register content
* @spi: The SPI device
* @reg: Register offset
*
* A read from the MAX7301 means two transfers; here, one message each
*
* Returns positive 8 bit value from device if successful or a
* negative value on error
*/
static int max7301_read(struct spi_device *spi, unsigned int reg)
/* A read from the MAX7301 means two transfers; here, one message each */
static int max7301_spi_read(struct device *dev, unsigned int reg)
{
int ret;
u16 word;
struct spi_device *spi = to_spi_device(dev);
word = 0x8000 | (reg << 8);
ret = spi_write(spi, (const u8 *)&word, sizeof(word));
@ -108,125 +51,13 @@ static int max7301_read(struct spi_device *spi, unsigned int reg)
return word & 0xff;
}
static int max7301_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct max7301 *ts = container_of(chip, struct max7301, chip);
u8 *config;
int ret;
/* First 4 pins are unused in the controller */
offset += 4;
config = &ts->port_config[offset >> 2];
mutex_lock(&ts->lock);
/* Standard GPIO API doesn't support pull-ups, has to be extended.
* Hard-coding no pollup for now. */
*config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3));
ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config);
mutex_unlock(&ts->lock);
return ret;
}
static int __max7301_set(struct max7301 *ts, unsigned offset, int value)
{
if (value) {
ts->out_level |= 1 << offset;
return max7301_write(ts->spi, 0x20 + offset, 0x01);
} else {
ts->out_level &= ~(1 << offset);
return max7301_write(ts->spi, 0x20 + offset, 0x00);
}
}
static int max7301_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
struct max7301 *ts = container_of(chip, struct max7301, chip);
u8 *config;
int ret;
/* First 4 pins are unused in the controller */
offset += 4;
config = &ts->port_config[offset >> 2];
mutex_lock(&ts->lock);
*config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3));
ret = __max7301_set(ts, offset, value);
if (!ret)
ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config);
mutex_unlock(&ts->lock);
return ret;
}
static int max7301_get(struct gpio_chip *chip, unsigned offset)
{
struct max7301 *ts = container_of(chip, struct max7301, chip);
int config, level = -EINVAL;
/* First 4 pins are unused in the controller */
offset += 4;
mutex_lock(&ts->lock);
config = (ts->port_config[offset >> 2] >> ((offset & 3) * 2)) & 3;
switch (config) {
case 1:
/* Output: return cached level */
level = !!(ts->out_level & (1 << offset));
break;
case 2:
case 3:
/* Input: read out */
level = max7301_read(ts->spi, 0x20 + offset) & 0x01;
}
mutex_unlock(&ts->lock);
return level;
}
static void max7301_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct max7301 *ts = container_of(chip, struct max7301, chip);
/* First 4 pins are unused in the controller */
offset += 4;
mutex_lock(&ts->lock);
__max7301_set(ts, offset, value);
mutex_unlock(&ts->lock);
}
static int __devinit max7301_probe(struct spi_device *spi)
{
struct max7301 *ts;
struct max7301_platform_data *pdata;
int i, ret;
int ret;
pdata = spi->dev.platform_data;
if (!pdata || !pdata->base) {
dev_dbg(&spi->dev, "incorrect or missing platform data\n");
return -EINVAL;
}
/*
* bits_per_word cannot be configured in platform data
*/
/* bits_per_word cannot be configured in platform data */
spi->bits_per_word = 16;
ret = spi_setup(spi);
if (ret < 0)
return ret;
@ -235,90 +66,35 @@ static int __devinit max7301_probe(struct spi_device *spi)
if (!ts)
return -ENOMEM;
mutex_init(&ts->lock);
ts->read = max7301_spi_read;
ts->write = max7301_spi_write;
ts->dev = &spi->dev;
dev_set_drvdata(&spi->dev, ts);
/* Power up the chip and disable IRQ output */
max7301_write(spi, 0x04, 0x01);
ts->spi = spi;
ts->chip.label = DRIVER_NAME,
ts->chip.direction_input = max7301_direction_input;
ts->chip.get = max7301_get;
ts->chip.direction_output = max7301_direction_output;
ts->chip.set = max7301_set;
ts->chip.base = pdata->base;
ts->chip.ngpio = PIN_NUMBER;
ts->chip.can_sleep = 1;
ts->chip.dev = &spi->dev;
ts->chip.owner = THIS_MODULE;
/*
* tristate all pins in hardware and cache the
* register values for later use.
*/
for (i = 1; i < 8; i++) {
int j;
/* 0xAA means input with internal pullup disabled */
max7301_write(spi, 0x08 + i, 0xAA);
ts->port_config[i] = 0xAA;
for (j = 0; j < 4; j++) {
int offset = (i - 1) * 4 + j;
ret = max7301_direction_input(&ts->chip, offset);
if (ret)
goto exit_destroy;
}
}
ret = gpiochip_add(&ts->chip);
ret = __max730x_probe(ts);
if (ret)
goto exit_destroy;
return ret;
exit_destroy:
dev_set_drvdata(&spi->dev, NULL);
mutex_destroy(&ts->lock);
kfree(ts);
kfree(ts);
return ret;
}
static int __devexit max7301_remove(struct spi_device *spi)
{
struct max7301 *ts;
int ret;
ts = dev_get_drvdata(&spi->dev);
if (ts == NULL)
return -ENODEV;
dev_set_drvdata(&spi->dev, NULL);
/* Power down the chip and disable IRQ output */
max7301_write(spi, 0x04, 0x00);
ret = gpiochip_remove(&ts->chip);
if (!ret) {
mutex_destroy(&ts->lock);
kfree(ts);
} else
dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
ret);
return ret;
return __max730x_remove(&spi->dev);
}
static const struct spi_device_id max7301_id[] = {
{ "max7301", 0 },
{ }
};
MODULE_DEVICE_TABLE(spi, max7301_id);
static struct spi_driver max7301_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
.name = "max7301",
.owner = THIS_MODULE,
},
.probe = max7301_probe,
.remove = __devexit_p(max7301_remove),
.probe = max7301_probe,
.remove = __devexit_p(max7301_remove),
.id_table = max7301_id,
};
static int __init max7301_init(void)
@ -336,7 +112,6 @@ static void __exit max7301_exit(void)
}
module_exit(max7301_exit);
MODULE_AUTHOR("Juergen Beisert");
MODULE_AUTHOR("Juergen Beisert, Wolfram Sang");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MAX7301 SPI based GPIO-Expander");
MODULE_ALIAS("spi:" DRIVER_NAME);
MODULE_DESCRIPTION("MAX7301 GPIO-Expander");

244
drivers/gpio/max730x.c Normal file
View File

@ -0,0 +1,244 @@
/**
* drivers/gpio/max7301.c
*
* Copyright (C) 2006 Juergen Beisert, Pengutronix
* Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix
* Copyright (C) 2009 Wolfram Sang, Pengutronix
*
* 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.
*
* The Maxim MAX7300/1 device is an I2C/SPI driven GPIO expander. There are
* 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more
* details
* Note:
* - DIN must be stable at the rising edge of clock.
* - when writing:
* - always clock in 16 clocks at once
* - at DIN: D15 first, D0 last
* - D0..D7 = databyte, D8..D14 = commandbyte
* - D15 = low -> write command
* - when reading
* - always clock in 16 clocks at once
* - at DIN: D15 first, D0 last
* - D0..D7 = dummy, D8..D14 = register address
* - D15 = high -> read command
* - raise CS and assert it again
* - always clock in 16 clocks at once
* - at DOUT: D15 first, D0 last
* - D0..D7 contains the data from the first cycle
*
* The driver exports a standard gpiochip interface
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/spi/max7301.h>
#include <linux/gpio.h>
/*
* Pin configurations, see MAX7301 datasheet page 6
*/
#define PIN_CONFIG_MASK 0x03
#define PIN_CONFIG_IN_PULLUP 0x03
#define PIN_CONFIG_IN_WO_PULLUP 0x02
#define PIN_CONFIG_OUT 0x01
#define PIN_NUMBER 28
static int max7301_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct max7301 *ts = container_of(chip, struct max7301, chip);
u8 *config;
u8 offset_bits;
int ret;
/* First 4 pins are unused in the controller */
offset += 4;
offset_bits = (offset & 3) << 1;
config = &ts->port_config[offset >> 2];
mutex_lock(&ts->lock);
/* Standard GPIO API doesn't support pull-ups, has to be extended.
* Hard-coding no pollup for now. */
*config = (*config & ~(PIN_CONFIG_MASK << offset_bits))
| (PIN_CONFIG_IN_WO_PULLUP << offset_bits);
ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);
mutex_unlock(&ts->lock);
return ret;
}
static int __max7301_set(struct max7301 *ts, unsigned offset, int value)
{
if (value) {
ts->out_level |= 1 << offset;
return ts->write(ts->dev, 0x20 + offset, 0x01);
} else {
ts->out_level &= ~(1 << offset);
return ts->write(ts->dev, 0x20 + offset, 0x00);
}
}
static int max7301_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
struct max7301 *ts = container_of(chip, struct max7301, chip);
u8 *config;
u8 offset_bits;
int ret;
/* First 4 pins are unused in the controller */
offset += 4;
offset_bits = (offset & 3) << 1;
config = &ts->port_config[offset >> 2];
mutex_lock(&ts->lock);
*config = (*config & ~(PIN_CONFIG_MASK << offset_bits))
| (PIN_CONFIG_OUT << offset_bits);
ret = __max7301_set(ts, offset, value);
if (!ret)
ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);
mutex_unlock(&ts->lock);
return ret;
}
static int max7301_get(struct gpio_chip *chip, unsigned offset)
{
struct max7301 *ts = container_of(chip, struct max7301, chip);
int config, level = -EINVAL;
/* First 4 pins are unused in the controller */
offset += 4;
mutex_lock(&ts->lock);
config = (ts->port_config[offset >> 2] >> ((offset & 3) << 1))
& PIN_CONFIG_MASK;
switch (config) {
case PIN_CONFIG_OUT:
/* Output: return cached level */
level = !!(ts->out_level & (1 << offset));
break;
case PIN_CONFIG_IN_WO_PULLUP:
case PIN_CONFIG_IN_PULLUP:
/* Input: read out */
level = ts->read(ts->dev, 0x20 + offset) & 0x01;
}
mutex_unlock(&ts->lock);
return level;
}
static void max7301_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct max7301 *ts = container_of(chip, struct max7301, chip);
/* First 4 pins are unused in the controller */
offset += 4;
mutex_lock(&ts->lock);
__max7301_set(ts, offset, value);
mutex_unlock(&ts->lock);
}
int __devinit __max730x_probe(struct max7301 *ts)
{
struct device *dev = ts->dev;
struct max7301_platform_data *pdata;
int i, ret;
pdata = dev->platform_data;
if (!pdata || !pdata->base) {
dev_err(dev, "incorrect or missing platform data\n");
return -EINVAL;
}
mutex_init(&ts->lock);
dev_set_drvdata(dev, ts);
/* Power up the chip and disable IRQ output */
ts->write(dev, 0x04, 0x01);
ts->chip.label = dev->driver->name;
ts->chip.direction_input = max7301_direction_input;
ts->chip.get = max7301_get;
ts->chip.direction_output = max7301_direction_output;
ts->chip.set = max7301_set;
ts->chip.base = pdata->base;
ts->chip.ngpio = PIN_NUMBER;
ts->chip.can_sleep = 1;
ts->chip.dev = dev;
ts->chip.owner = THIS_MODULE;
/*
* tristate all pins in hardware and cache the
* register values for later use.
*/
for (i = 1; i < 8; i++) {
int j;
/* 0xAA means input with internal pullup disabled */
ts->write(dev, 0x08 + i, 0xAA);
ts->port_config[i] = 0xAA;
for (j = 0; j < 4; j++) {
int offset = (i - 1) * 4 + j;
ret = max7301_direction_input(&ts->chip, offset);
if (ret)
goto exit_destroy;
}
}
ret = gpiochip_add(&ts->chip);
if (ret)
goto exit_destroy;
return ret;
exit_destroy:
dev_set_drvdata(dev, NULL);
mutex_destroy(&ts->lock);
return ret;
}
EXPORT_SYMBOL_GPL(__max730x_probe);
int __devexit __max730x_remove(struct device *dev)
{
struct max7301 *ts = dev_get_drvdata(dev);
int ret;
if (ts == NULL)
return -ENODEV;
dev_set_drvdata(dev, NULL);
/* Power down the chip and disable IRQ output */
ts->write(dev, 0x04, 0x00);
ret = gpiochip_remove(&ts->chip);
if (!ret) {
mutex_destroy(&ts->lock);
kfree(ts);
} else
dev_err(dev, "Failed to remove GPIO controller: %d\n", ret);
return ret;
}
EXPORT_SYMBOL_GPL(__max730x_remove);

18
include/linux/spi/max7301.h
View File

@ -1,9 +1,27 @@
#ifndef LINUX_SPI_MAX7301_H
#define LINUX_SPI_MAX7301_H
#include <linux/gpio.h>
/*
* Some registers must be read back to modify.
* To save time we cache them here in memory
*/
struct max7301 {
struct mutex lock;
u8 port_config[8]; /* field 0 is unused */
u32 out_level; /* cached output levels */
struct gpio_chip chip;
struct device *dev;
int (*write)(struct device *dev, unsigned int reg, unsigned int val);
int (*read)(struct device *dev, unsigned int reg);
};
struct max7301_platform_data {
/* number assigned to the first GPIO */
unsigned base;
};
extern int __max730x_remove(struct device *dev);
extern int __max730x_probe(struct max7301 *ts);
#endif