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gpio: pcie-idio-24: Implement get_multiple/set_multiple callbacks

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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: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
William Breathitt Gray 2018-03-22 09:00:00 -04:00 committed by Linus Walleij
parent 810ebfc5ef
commit ca37081595
1 changed files with 117 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

117
drivers/gpio/gpio-pcie-idio-24.c
View file

@ -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);