The ACCES I/O PCI-IDIO-16 series of devices provides 16
optically-isolated digital inputs accessed via two 8-bit ports. Since
eight input lines are acquired on a single port input read, the
PCI-IDIO-16 GPIO driver may improve multiple input reads by utilizing a
get_multiple callback. This patch implements the
idio_16_gpio_get_multiple function which serves as the respective
get_multiple callback.
Signed-off-by: William Breathitt Gray <vilhelm.g...@gmail.com>
---
drivers/gpio/gpio-pci-idio-16.c | 48 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c
index 57d1b7fbf07b..8c5ec301c7ff 100644
--- a/drivers/gpio/gpio-pci-idio-16.c
+++ b/drivers/gpio/gpio-pci-idio-16.c
@@ -103,6 +103,53 @@ static int idio_16_gpio_get(struct gpio_chip *chip,
unsigned int offset)
return !!(ioread8(&idio16gpio->reg->in8_15) & (mask >> 24));
}
+static int idio_16_gpio_get_multiple(struct gpio_chip *chip,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip);
+ unsigned int i;
+ const unsigned int gpio_reg_size = 8;
+ unsigned int bit_word_offset;
+ unsigned int bits_mask;
+ const unsigned long reg_mask = GENMASK(gpio_reg_size, 0);
+ unsigned long port_state;
+
+ /* clear bits array to a clean slate */
+ for (i = 0; i < chip->ngpio; i += BITS_PER_LONG)
+ bits[i / BITS_PER_LONG] = 0;
+
+ /* get bits are evaluated a gpio register size at a time */
+ for (i = 0; i < chip->ngpio; i += gpio_reg_size) {
+ bit_word_offset = i % BITS_PER_LONG;
+ bits_mask = mask[BIT_WORD(i)] & (reg_mask << bit_word_offset);
+ if (!bits_mask) {
+ /* no get bits in this register so skip to next one */
+ continue;
+ }
+
+ /* read bits from current gpio register */
+ switch (i / gpio_reg_size) {
+ case 0:
+ port_state = ioread8(&idio16gpio->reg->out0_7);
+ break;
+ case 1:
+ port_state = ioread8(&idio16gpio->reg->out8_15);
+ break;
+ case 2:
+ port_state = ioread8(&idio16gpio->reg->in0_7);
+ break;
+ case 3:
+ port_state = ioread8(&idio16gpio->reg->in8_15);
+ break;
+ }
+
+ /* store acquired bits */
+ bits[BIT_WORD(i)] |= port_state << bit_word_offset;
+ }
+
+ return 0;
+}
+
static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
@@ -299,6 +346,7 @@ static int idio_16_probe(struct pci_dev *pdev, const struct
pci_device_id *id)
idio16gpio->chip.direction_input = idio_16_gpio_direction_input;
idio16gpio->chip.direction_output = idio_16_gpio_direction_output;
idio16gpio->chip.get = idio_16_gpio_get;
+ idio16gpio->chip.get_multiple = idio_16_gpio_get_multiple;
idio16gpio->chip.set = idio_16_gpio_set;
idio16gpio->chip.set_multiple = idio_16_gpio_set_multiple;
--
2.16.2
