Done by factoring out the generic routines from MAX7301 into MAX730X and
adding wrappers for MAX7300 (I2C) and MAX7301 (SPI).
Signed-off-by: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
Cc: Juergen Beisert <j.beisert@xxxxxxxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Anton Vorontsov <avorontsov@xxxxxxxxxxxxx>
Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Here is my current version which now allows to have one part as builtin and the
other as a module (discovered by Randy). Note that changes from V3 to V4 are
only built-tested (on x86 and x86-64) as I don't have access to the hardware
anymore. So, I think this should go to linux-next for another cycle.
Changes since V3:
* refactored into generic, i2c and spi part.
* no functional changes
Changes since V2:
* improve Kconfig logic. Main part depends now on I2C or SPI (Thanks again, Anton!).
Seperate busses are now 'default y' if a bus is present, so old defconfigs will
update automatically (it is also more convenient).
* use already present #defines instead of hardcoded values
* add some empty lines to make code more readable
Changes since V1:
* Use id_table for spi, too (Thanks to Anton for the hint!)
* removed some whitespace issues
* in driver init, remove first driver if registering the second fails
drivers/gpio/Kconfig | 13 ++-
drivers/gpio/Makefile | 2 +
drivers/gpio/max7300.c | 94 ++++++++++++++
drivers/gpio/max7301.c | 293 +++++--------------------------------------
drivers/gpio/max730x.c | 244 +++++++++++++++++++++++++++++++++++
include/linux/spi/max7301.h | 18 +++
6 files changed, 404 insertions(+), 260 deletions(-)
create mode 100644 drivers/gpio/max7300.c
create mode 100644 drivers/gpio/max730x.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 2ad0128..17f4206 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -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
@@ -201,8 +211,9 @@ 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"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 00a532c..c8ba441 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -6,6 +6,8 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o
obj-$(CONFIG_GPIO_ADP5520) += adp5520-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
diff --git a/drivers/gpio/max7300.c b/drivers/gpio/max7300.c
new file mode 100644
index 0000000..9d74eef
--- /dev/null
+++ b/drivers/gpio/max7300.c
@@ -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");
diff --git a/drivers/gpio/max7301.c b/drivers/gpio/max7301.c
index 480956f..965d9b1 100644
--- a/drivers/gpio/max7301.c
+++ b/drivers/gpio/max7301.c
@@ -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;
-
- pdata = spi->dev.platform_data;
- if (!pdata || !pdata->base) {
- dev_dbg(&spi->dev, "incorrect or missing platform data\n");
- return -EINVAL;
- }
+ int ret;
- /*
- * 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);
-
- dev_set_drvdata(&spi->dev, ts);
+ ts->read = max7301_spi_read;
+ ts->write = max7301_spi_write;
+ ts->dev = &spi->dev;
- /* 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");
diff --git a/drivers/gpio/max730x.c b/drivers/gpio/max730x.c
new file mode 100644
index 0000000..c9bced5
--- /dev/null
+++ b/drivers/gpio/max730x.c
@@ -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);
diff --git a/include/linux/spi/max7301.h b/include/linux/spi/max7301.h
index 6dfd83f..34af0a3 100644
--- a/include/linux/spi/max7301.h
+++ b/include/linux/spi/max7301.h
@@ -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
--
1.6.3.3
--
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