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William Breathitt Graylinusw
William Breathitt Gray
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linusw
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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: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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‎drivers/gpio/gpio-pcie-idio-24.c

Lines changed: 117 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -15,6 +15,7 @@
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* This driver supports the following ACCES devices: PCIe-IDIO-24,
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* PCIe-IDI-24, PCIe-IDO-24, and PCIe-IDIO-12.
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*/
18+
#include <linux/bitmap.h>
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#include <linux/bitops.h>
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#include <linux/device.h>
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#include <linux/errno.h>
@@ -193,6 +194,61 @@ static int idio_24_gpio_get(struct gpio_chip *chip, unsigned int offset)
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return !!(ioread8(&idio24gpio->reg->ttl_in0_7) & offset_mask);
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}
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static int idio_24_gpio_get_multiple(struct gpio_chip *chip,
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unsigned long *mask, unsigned long *bits)
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{
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struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
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size_t i;
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const unsigned int gpio_reg_size = 8;
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unsigned int bits_offset;
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size_t word_index;
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unsigned int word_offset;
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unsigned long word_mask;
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const unsigned long port_mask = GENMASK(gpio_reg_size - 1, 0);
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unsigned long port_state;
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u8 __iomem ports[] = {
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idio24gpio->reg->out0_7, idio24gpio->reg->out8_15,
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idio24gpio->reg->out16_23, idio24gpio->reg->in0_7,
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idio24gpio->reg->in8_15, idio24gpio->reg->in16_23,
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};
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const unsigned long out_mode_mask = BIT(1);
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/* clear bits array to a clean slate */
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bitmap_zero(bits, chip->ngpio);
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/* get bits are evaluated a gpio port register at a time */
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for (i = 0; i < ARRAY_SIZE(ports); i++) {
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/* gpio offset in bits array */
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bits_offset = i * gpio_reg_size;
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/* word index for bits array */
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word_index = BIT_WORD(bits_offset);
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/* gpio offset within current word of bits array */
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word_offset = bits_offset % BITS_PER_LONG;
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/* mask of get bits for current gpio within current word */
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word_mask = mask[word_index] & (port_mask << word_offset);
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if (!word_mask) {
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/* no get bits in this port so skip to next one */
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continue;
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}
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/* read bits from current gpio port (port 6 is TTL GPIO) */
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if (i < 6)
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port_state = ioread8(ports + i);
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else if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)
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port_state = ioread8(&idio24gpio->reg->ttl_out0_7);
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else
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port_state = ioread8(&idio24gpio->reg->ttl_in0_7);
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/* store acquired bits at respective bits array offset */
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bits[word_index] |= port_state << word_offset;
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}
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return 0;
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}
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static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,
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int value)
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{
@@ -234,6 +290,65 @@ static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,
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raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
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}
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static void idio_24_gpio_set_multiple(struct gpio_chip *chip,
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unsigned long *mask, unsigned long *bits)
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{
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struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
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size_t i;
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unsigned long bits_offset;
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unsigned long gpio_mask;
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const unsigned int gpio_reg_size = 8;
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const unsigned long port_mask = GENMASK(gpio_reg_size, 0);
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unsigned long flags;
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unsigned int out_state;
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u8 __iomem ports[] = {
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idio24gpio->reg->out0_7, idio24gpio->reg->out8_15,
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idio24gpio->reg->out16_23
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};
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const unsigned long out_mode_mask = BIT(1);
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const unsigned int ttl_offset = 48;
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const size_t ttl_i = BIT_WORD(ttl_offset);
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const unsigned int word_offset = ttl_offset % BITS_PER_LONG;
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const unsigned long ttl_mask = (mask[ttl_i] >> word_offset) & port_mask;
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const unsigned long ttl_bits = (bits[ttl_i] >> word_offset) & ttl_mask;
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/* set bits are processed a gpio port register at a time */
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for (i = 0; i < ARRAY_SIZE(ports); i++) {
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/* gpio offset in bits array */
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bits_offset = i * gpio_reg_size;
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/* check if any set bits for current port */
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gpio_mask = (*mask >> bits_offset) & port_mask;
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if (!gpio_mask) {
323+
/* no set bits for this port so move on to next port */
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continue;
325+
}
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raw_spin_lock_irqsave(&idio24gpio->lock, flags);
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/* process output lines */
330+
out_state = ioread8(ports + i) & ~gpio_mask;
331+
out_state |= (*bits >> bits_offset) & gpio_mask;
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iowrite8(out_state, ports + i);
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raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
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}
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/* check if setting TTL lines and if they are in output mode */
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if (!ttl_mask || !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask))
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return;
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341+
/* handle TTL output */
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raw_spin_lock_irqsave(&idio24gpio->lock, flags);
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/* process output lines */
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out_state = ioread8(&idio24gpio->reg->ttl_out0_7) & ~ttl_mask;
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out_state |= ttl_bits;
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iowrite8(out_state, &idio24gpio->reg->ttl_out0_7);
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raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
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}
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237352
static void idio_24_irq_ack(struct irq_data *data)
238353
{
239354
}
@@ -397,7 +512,9 @@ static int idio_24_probe(struct pci_dev *pdev, const struct pci_device_id *id)
397512
idio24gpio->chip.direction_input = idio_24_gpio_direction_input;
398513
idio24gpio->chip.direction_output = idio_24_gpio_direction_output;
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idio24gpio->chip.get = idio_24_gpio_get;
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idio24gpio->chip.get_multiple = idio_24_gpio_get_multiple;
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idio24gpio->chip.set = idio_24_gpio_set;
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idio24gpio->chip.set_multiple = idio_24_gpio_set_multiple;
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402519
raw_spin_lock_init(&idio24gpio->lock);
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