Commit 64d2f459 authored by Radu Rendec's avatar Radu Rendec Committed by Bartosz Golaszewski
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gpio: pcf857x: Implement get_multiple/set_multiple methods 



This change allows the GPIO core to read/change multiple pins in a
single driver call and subsequent I2C transfer. It helps a lot with
PCF857x devices, since their I2C protocol always reads/changes all
existing pins anyway. Therefore, when the GPIO client code does a bulk
operation on multiple pins, the driver makes a single I2C transfer.

Signed-off-by: default avatarRadu Rendec <radu.rendec@gmail.com>
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 17a5f49b

drivers/gpio/gpio-pcf857x.c

+29 −0
Original line number Diff line number Diff line
@@ -141,6 +141,21 @@ static int pcf857x_get(struct gpio_chip *chip, unsigned int offset) 
	return (value < 0) ? value : !!(value & (1 << offset));

}



static int pcf857x_get_multiple(struct gpio_chip *chip, unsigned long *mask,

				unsigned long *bits)

{

	struct pcf857x *gpio = gpiochip_get_data(chip);

	int value = gpio->read(gpio->client);



	if (value < 0)

		return value;



	*bits &= ~*mask;

	*bits |= value & *mask;



	return 0;

}



static int pcf857x_output(struct gpio_chip *chip, unsigned int offset, int value)

{

	struct pcf857x *gpio = gpiochip_get_data(chip);
@@ -163,6 +178,18 @@ static void pcf857x_set(struct gpio_chip *chip, unsigned int offset, int value) 
	pcf857x_output(chip, offset, value);

}



static void pcf857x_set_multiple(struct gpio_chip *chip, unsigned long *mask,

				 unsigned long *bits)

{

	struct pcf857x *gpio = gpiochip_get_data(chip);



	mutex_lock(&gpio->lock);

	gpio->out &= ~*mask;

	gpio->out |= *bits & *mask;

	gpio->write(gpio->client, gpio->out);

	mutex_unlock(&gpio->lock);

}



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



static irqreturn_t pcf857x_irq(int irq, void *data)
@@ -275,7 +302,9 @@ static int pcf857x_probe(struct i2c_client *client) 
	gpio->chip.parent		= &client->dev;

	gpio->chip.owner		= THIS_MODULE;

	gpio->chip.get			= pcf857x_get;

	gpio->chip.get_multiple		= pcf857x_get_multiple;

	gpio->chip.set			= pcf857x_set;

	gpio->chip.set_multiple		= pcf857x_set_multiple;

	gpio->chip.direction_input	= pcf857x_input;

	gpio->chip.direction_output	= pcf857x_output;

	gpio->chip.ngpio		= id->driver_data;