Commit 2443c2e1 authored by Alban Bedel's avatar Alban Bedel Committed by Bartosz Golaszewski
Browse files

gpio: kempld: Add support for get/set multiple 



As the bus accesses are quiet slow with this device, supporting the
get/set multiple API can help with performences. The implementation
tries to keep the number of bus access to a minimum by checking
the mask to only read or write the needed bytes.

Signed-off-by: default avatarAlban Bedel <alban.bedel@lht.dlh.de>
Link: https://patch.msgid.link/20260311143120.2179347-4-alban.bedel@lht.dlh.de


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
parent 84cb463d

drivers/gpio/gpio-kempld.c

+60 −0
Original line number Diff line number Diff line
@@ -65,6 +65,33 @@ static int kempld_gpio_get(struct gpio_chip *chip, unsigned offset) 
	return !!kempld_gpio_get_bit(pld, KEMPLD_GPIO_LVL, offset);

}



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

				    unsigned long *bits)

{

	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);

	struct kempld_device_data *pld = gpio->pld;

	u8 reg = KEMPLD_GPIO_LVL;

	unsigned int shift;



	bits[0] &= ~mask[0];



	kempld_get_mutex(pld);



	/* Try to reduce to a single 8 bits access if possible */

	for (shift = 0; shift < gpio->chip.ngpio; shift += 8, reg++) {

		unsigned long msk = (mask[0] >> shift) & 0xff;



		if (!msk)

			continue;



		bits[0] |= (kempld_read8(pld, reg) & msk) << shift;

	}



	kempld_release_mutex(pld);



	return 0;

}



static int kempld_gpio_set(struct gpio_chip *chip, unsigned int offset,

			   int value)

{
@@ -78,6 +105,37 @@ static int kempld_gpio_set(struct gpio_chip *chip, unsigned int offset, 
	return 0;

}



static int kempld_gpio_set_multiple(struct gpio_chip *chip,

				    unsigned long *mask, unsigned long *bits)

{

	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);

	struct kempld_device_data *pld = gpio->pld;

	u8 reg = gpio->out_lvl_reg;

	unsigned int shift;



	kempld_get_mutex(pld);



	/* Try to reduce to a single 8 bits access if possible */

	for (shift = 0; shift < gpio->chip.ngpio; shift += 8, reg++) {

		u8 val, msk = mask[0] >> shift;



		if (!msk)

			continue;



		if (msk != 0xFF)

			val = kempld_read8(pld, reg) & ~msk;

		else

			val = 0;



		val |= (bits[0] >> shift) & msk;

		kempld_write8(pld, reg, val);

	}



	kempld_release_mutex(pld);



	return 0;

}



static int kempld_gpio_direction_input(struct gpio_chip *chip, unsigned offset)

{

	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
@@ -180,7 +238,9 @@ static int kempld_gpio_probe(struct platform_device *pdev) 
	chip->direction_output = kempld_gpio_direction_output;

	chip->get_direction = kempld_gpio_get_direction;

	chip->get = kempld_gpio_get;

	chip->get_multiple = kempld_gpio_get_multiple;

	chip->set = kempld_gpio_set;

	chip->set_multiple = kempld_gpio_set_multiple;

	chip->ngpio = kempld_gpio_pincount(pld);

	if (chip->ngpio == 0) {

		dev_err(dev, "No GPIO pins detected\n");