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Commit ca370815 authored by William Breathitt Gray's avatar William Breathitt Gray Committed by Linus Walleij
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gpio: pcie-idio-24: Implement get_multiple/set_multiple callbacks 



The ACCES I/O PCIe-IDIO-24 series of devices provides 24
optically-isolated digital I/O accessed via six 8-bit ports. Since eight
input lines are acquired on a single port input read -- and similarly
eight output lines are set on a single port output write -- the
PCIe-IDIO-24 GPIO driver may improve multiple I/O reads/writes by
utilizing a get_multiple/set_multiple callbacks. This patch implements
the idio_24_gpio_get_multiple function which serves as the respective
get_multiple callback, and implements the idio_24_gpio_set_multiple
function which serves as the respective set_multiple callback.

Signed-off-by: default avatarWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 810ebfc5

drivers/gpio/gpio-pcie-idio-24.c

+117 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
 * This driver supports the following ACCES devices: PCIe-IDIO-24,

 * PCIe-IDI-24, PCIe-IDO-24, and PCIe-IDIO-12.

 */

#include <linux/bitmap.h>

#include <linux/bitops.h>

#include <linux/device.h>

#include <linux/errno.h>
@@ -193,6 +194,61 @@ static int idio_24_gpio_get(struct gpio_chip *chip, unsigned int offset) 
	return !!(ioread8(&idio24gpio->reg->ttl_in0_7) & offset_mask);

}



static int idio_24_gpio_get_multiple(struct gpio_chip *chip,

	unsigned long *mask, unsigned long *bits)

{

	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);

	size_t i;

	const unsigned int gpio_reg_size = 8;

	unsigned int bits_offset;

	size_t word_index;

	unsigned int word_offset;

	unsigned long word_mask;

	const unsigned long port_mask = GENMASK(gpio_reg_size - 1, 0);

	unsigned long port_state;

	u8 __iomem ports[] = {

		idio24gpio->reg->out0_7, idio24gpio->reg->out8_15,

		idio24gpio->reg->out16_23, idio24gpio->reg->in0_7,

		idio24gpio->reg->in8_15, idio24gpio->reg->in16_23,

	};

	const unsigned long out_mode_mask = BIT(1);



	/* clear bits array to a clean slate */

	bitmap_zero(bits, chip->ngpio);



	/* get bits are evaluated a gpio port register at a time */

	for (i = 0; i < ARRAY_SIZE(ports); i++) {

		/* gpio offset in bits array */

		bits_offset = i * gpio_reg_size;



		/* word index for bits array */

		word_index = BIT_WORD(bits_offset);



		/* gpio offset within current word of bits array */

		word_offset = bits_offset % BITS_PER_LONG;



		/* mask of get bits for current gpio within current word */

		word_mask = mask[word_index] & (port_mask << word_offset);

		if (!word_mask) {

			/* no get bits in this port so skip to next one */

			continue;

		}



		/* read bits from current gpio port (port 6 is TTL GPIO) */

		if (i < 6)

			port_state = ioread8(ports + i);

		else if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)

			port_state = ioread8(&idio24gpio->reg->ttl_out0_7);

		else

			port_state = ioread8(&idio24gpio->reg->ttl_in0_7);



		/* store acquired bits at respective bits array offset */

		bits[word_index] |= port_state << word_offset;

	}



	return 0;

}



static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,

	int value)

{
@@ -234,6 +290,65 @@ static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset, 
	raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);

}



static void idio_24_gpio_set_multiple(struct gpio_chip *chip,

	unsigned long *mask, unsigned long *bits)

{

	struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);

	size_t i;

	unsigned long bits_offset;

	unsigned long gpio_mask;

	const unsigned int gpio_reg_size = 8;

	const unsigned long port_mask = GENMASK(gpio_reg_size, 0);

	unsigned long flags;

	unsigned int out_state;

	u8 __iomem ports[] = {

		idio24gpio->reg->out0_7, idio24gpio->reg->out8_15,

		idio24gpio->reg->out16_23

	};

	const unsigned long out_mode_mask = BIT(1);

	const unsigned int ttl_offset = 48;

	const size_t ttl_i = BIT_WORD(ttl_offset);

	const unsigned int word_offset = ttl_offset % BITS_PER_LONG;

	const unsigned long ttl_mask = (mask[ttl_i] >> word_offset) & port_mask;

	const unsigned long ttl_bits = (bits[ttl_i] >> word_offset) & ttl_mask;



	/* set bits are processed a gpio port register at a time */

	for (i = 0; i < ARRAY_SIZE(ports); i++) {

		/* gpio offset in bits array */

		bits_offset = i * gpio_reg_size;



		/* check if any set bits for current port */

		gpio_mask = (*mask >> bits_offset) & port_mask;

		if (!gpio_mask) {

			/* no set bits for this port so move on to next port */

			continue;

		}



		raw_spin_lock_irqsave(&idio24gpio->lock, flags);



		/* process output lines */

		out_state = ioread8(ports + i) & ~gpio_mask;

		out_state |= (*bits >> bits_offset) & gpio_mask;

		iowrite8(out_state, ports + i);



		raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);

	}



	/* check if setting TTL lines and if they are in output mode */

	if (!ttl_mask || !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask))

		return;



	/* handle TTL output */

	raw_spin_lock_irqsave(&idio24gpio->lock, flags);



	/* process output lines */

	out_state = ioread8(&idio24gpio->reg->ttl_out0_7) & ~ttl_mask;

	out_state |= ttl_bits;

	iowrite8(out_state, &idio24gpio->reg->ttl_out0_7);



	raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);

}



static void idio_24_irq_ack(struct irq_data *data)

{

}
@@ -397,7 +512,9 @@ static int idio_24_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	idio24gpio->chip.direction_input = idio_24_gpio_direction_input;

	idio24gpio->chip.direction_output = idio_24_gpio_direction_output;

	idio24gpio->chip.get = idio_24_gpio_get;

	idio24gpio->chip.get_multiple = idio_24_gpio_get_multiple;

	idio24gpio->chip.set = idio_24_gpio_set;

	idio24gpio->chip.set_multiple = idio_24_gpio_set_multiple;



	raw_spin_lock_init(&idio24gpio->lock);