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gpio: pcf857x: share 8/16 bit access functions
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This patch adds 8/16 bit write/read functions,
and shared gpio input/output/set/get functions.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Kuninori Morimoto authored and Linus Walleij committed Jul 12, 2012
1 parent da03d74 commit 0c65ddd
Showing 1 changed file with 31 additions and 62 deletions.
93 changes: 31 additions & 62 deletions drivers/gpio/gpio-pcf857x.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -61,61 +61,28 @@ struct pcf857x {
struct i2c_client *client;
struct mutex lock; /* protect 'out' */
unsigned out; /* software latch */

int (*write)(struct i2c_client *client, unsigned data);
int (*read)(struct i2c_client *client);
};

/*-------------------------------------------------------------------------*/

/* 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)
static int i2c_write_le8(struct i2c_client *client, unsigned data)
{
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;
return i2c_smbus_write_byte(client, data);
}

static void pcf857x_set8(struct gpio_chip *chip, unsigned offset, int value)
static int i2c_read_le8(struct i2c_client *client)
{
pcf857x_output8(chip, offset, value);
return (int)i2c_smbus_read_byte(client);
}

/*-------------------------------------------------------------------------*/

/* Talk to 16-bit I/O expander */

static int i2c_write_le16(struct i2c_client *client, u16 word)
static int i2c_write_le16(struct i2c_client *client, unsigned word)
{
u8 buf[2] = { word & 0xff, word >> 8, };
int status;
Expand All @@ -135,29 +102,31 @@ static int i2c_read_le16(struct i2c_client *client)
return (buf[1] << 8) | buf[0];
}

static int pcf857x_input16(struct gpio_chip *chip, unsigned offset)
/*-------------------------------------------------------------------------*/

static int pcf857x_input(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);
status = gpio->write(gpio->client, gpio->out);
mutex_unlock(&gpio->lock);

return status;
}

static int pcf857x_get16(struct gpio_chip *chip, unsigned offset)
static int pcf857x_get(struct gpio_chip *chip, unsigned offset)
{
struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
int value;

value = i2c_read_le16(gpio->client);
value = gpio->read(gpio->client);
return (value < 0) ? 0 : (value & (1 << offset));
}

static int pcf857x_output16(struct gpio_chip *chip, unsigned offset, int value)
static int pcf857x_output(struct gpio_chip *chip, unsigned offset, int value)
{
struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
unsigned bit = 1 << offset;
Expand All @@ -168,15 +137,15 @@ static int pcf857x_output16(struct gpio_chip *chip, unsigned offset, int value)
gpio->out |= bit;
else
gpio->out &= ~bit;
status = i2c_write_le16(gpio->client, gpio->out);
status = gpio->write(gpio->client, gpio->out);
mutex_unlock(&gpio->lock);

return status;
}

static void pcf857x_set16(struct gpio_chip *chip, unsigned offset, int value)
static void pcf857x_set(struct gpio_chip *chip, unsigned offset, int value)
{
pcf857x_output16(chip, offset, value);
pcf857x_output(chip, offset, value);
}

/*-------------------------------------------------------------------------*/
Expand All @@ -200,10 +169,15 @@ static int pcf857x_probe(struct i2c_client *client,

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;
gpio->chip.base = pdata ? pdata->gpio_base : -1;
gpio->chip.can_sleep = 1;
gpio->chip.dev = &client->dev;
gpio->chip.owner = THIS_MODULE;
gpio->chip.get = pcf857x_get;
gpio->chip.set = pcf857x_set;
gpio->chip.direction_input = pcf857x_input;
gpio->chip.direction_output = pcf857x_output;
gpio->chip.ngpio = id->driver_data;

/* NOTE: the OnSemi jlc1562b is also largely compatible with
* these parts, notably for output. It has a low-resolution
Expand All @@ -216,12 +190,9 @@ static int pcf857x_probe(struct i2c_client *client,
*
* 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;
gpio->write = i2c_write_le8;
gpio->read = i2c_read_le8;

if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_BYTE))
Expand All @@ -238,10 +209,8 @@ static int pcf857x_probe(struct i2c_client *client,
* 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;
gpio->write = i2c_write_le16;
gpio->read = i2c_read_le16;

if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
status = -EIO;
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