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author | William Breathitt Gray <vilhelm.gray@gmail.com> | 2018-03-22 08:59:48 -0400 |
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committer | Linus Walleij <linus.walleij@linaro.org> | 2018-03-26 10:24:06 +0200 |
commit | 810ebfc5efca9a05c57e5d2bad0f944b0f24267d (patch) | |
tree | 0f84044673fe3c7e99d9246e8ac5bec5b8cd3762 | |
parent | 15f59cfff92bcbbb67e1b7ebb4d10b845797bdeb (diff) | |
download | linux-stable-810ebfc5efca9a05c57e5d2bad0f944b0f24267d.tar.gz linux-stable-810ebfc5efca9a05c57e5d2bad0f944b0f24267d.tar.bz2 linux-stable-810ebfc5efca9a05c57e5d2bad0f944b0f24267d.zip |
gpio: pci-idio-16: Implement get_multiple callback
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.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r-- | drivers/gpio/gpio-pci-idio-16.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c index 57d1b7fbf07b..1948724d8c36 100644 --- a/drivers/gpio/gpio-pci-idio-16.c +++ b/drivers/gpio/gpio-pci-idio-16.c @@ -11,6 +11,7 @@ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. */ +#include <linux/bitmap.h> #include <linux/bitops.h> #include <linux/device.h> #include <linux/errno.h> @@ -103,6 +104,54 @@ 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); + 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[] = { + idio16gpio->reg->out0_7, idio16gpio->reg->out8_15, + idio16gpio->reg->in0_7, idio16gpio->reg->in8_15, + }; + + /* 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_state = ioread8(ports + i); + + /* store acquired bits at respective bits array offset */ + bits[word_index] |= port_state << word_offset; + } + + return 0; +} + static void idio_16_gpio_set(struct gpio_chip *chip, unsigned int offset, int value) { @@ -299,6 +348,7 @@ 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; |