diff options
Diffstat (limited to 'drivers/gpio/gpio-ws16c48.c')
| -rw-r--r-- | drivers/gpio/gpio-ws16c48.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c index 746648244bf3..c7028eb0b8e1 100644 --- a/drivers/gpio/gpio-ws16c48.c +++ b/drivers/gpio/gpio-ws16c48.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> @@ -129,6 +130,51 @@ static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset) return !!(port_state & mask); } +static int ws16c48_gpio_get_multiple(struct gpio_chip *chip, + unsigned long *mask, unsigned long *bits) +{ + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned int gpio_reg_size = 8; + size_t i; + const size_t num_ports = chip->ngpio / gpio_reg_size; + 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; + + /* 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 < num_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 = inb(ws16c48gpio->base + i); + + /* store acquired bits at respective bits array offset */ + bits[word_index] |= port_state << word_offset; + } + + return 0; +} + static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); @@ -383,6 +429,7 @@ static int ws16c48_probe(struct device *dev, unsigned int id) ws16c48gpio->chip.direction_input = ws16c48_gpio_direction_input; ws16c48gpio->chip.direction_output = ws16c48_gpio_direction_output; ws16c48gpio->chip.get = ws16c48_gpio_get; + ws16c48gpio->chip.get_multiple = ws16c48_gpio_get_multiple; ws16c48gpio->chip.set = ws16c48_gpio_set; ws16c48gpio->chip.set_multiple = ws16c48_gpio_set_multiple; ws16c48gpio->base = base[id]; |