From f72b10713cf5a9f6a425bdbd8da093cb02990d4d Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Thu, 22 Mar 2018 09:00:31 -0400 Subject: gpio: 104-idi-48: Implement get_multiple callback The ACCES I/O 104-IDI-48 series of devices provides 48 optically-isolated inputs accessed via six 8-bit ports. Since eight input lines are acquired on a single port input read, the 104-IDI-48 GPIO driver may improve multiple input reads by utilizing a get_multiple callback. This patch implements the idi_48_gpio_get_multiple function which serves as the respective get_multiple callback. Signed-off-by: William Breathitt Gray Signed-off-by: Linus Walleij --- drivers/gpio/gpio-104-idi-48.c | 47 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) (limited to 'drivers/gpio/gpio-104-idi-48.c') diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c index add859d59766..f35632609379 100644 --- a/drivers/gpio/gpio-104-idi-48.c +++ b/drivers/gpio/gpio-104-idi-48.c @@ -14,6 +14,7 @@ * This driver supports the following ACCES devices: 104-IDI-48A, * 104-IDI-48AC, 104-IDI-48B, and 104-IDI-48BC. */ +#include #include #include #include @@ -88,6 +89,51 @@ static int idi_48_gpio_get(struct gpio_chip *chip, unsigned offset) return 0; } +static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask, + unsigned long *bits) +{ + struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip); + size_t i; + const size_t ports[] = { 0, 1, 2, 4, 5, 6 }; + 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; + + /* 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 = inb(idi48gpio->base + ports[i]); + + /* store acquired bits at respective bits array offset */ + bits[word_index] |= port_state << word_offset; + } + + return 0; +} + static void idi_48_irq_ack(struct irq_data *data) { } @@ -256,6 +302,7 @@ static int idi_48_probe(struct device *dev, unsigned int id) idi48gpio->chip.get_direction = idi_48_gpio_get_direction; idi48gpio->chip.direction_input = idi_48_gpio_direction_input; idi48gpio->chip.get = idi_48_gpio_get; + idi48gpio->chip.get_multiple = idi_48_gpio_get_multiple; idi48gpio->base = base[id]; raw_spin_lock_init(&idi48gpio->lock); -- cgit v1.2.3-55-g7522