| Message ID | 486eb9bad0440ed305a78d9fc990728cbeb7d43e.1521301345.git.vilhelm.gray@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Mar 17, 2018 at 5:50 PM, William Breathitt Gray <vilhelm.gray@gmail.com> wrote: > The ACCES I/O 104-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 > 104-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. > +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); > + > + *bits = 0; > + if (*mask & 0xFF0000) GENMASK(23, 16) ? > + *bits |= (unsigned long)inb(idio16gpio->base + 1) << 16; Do you need casting? > + if (*mask & 0xFF000000) GENMASK(31, 24) ? Alternative (and for above): (*mask >> 24) & 0xff (*mask >> 16) & 0xff > + *bits |= (unsigned long)inb(idio16gpio->base + 5) << 24; Do you need casting? > + > + return 0; > +} > + > static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value) > { > struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); > @@ -244,6 +258,7 @@ static int idio_16_probe(struct device *dev, unsigned int 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; > idio16gpio->base = base[id]; > -- > 2.16.2 >
On Wed, Mar 21, 2018 at 05:32:03PM +0200, Andy Shevchenko wrote: >On Sat, Mar 17, 2018 at 5:50 PM, William Breathitt Gray ><vilhelm.gray@gmail.com> wrote: >> The ACCES I/O 104-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 >> 104-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. > >> +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); >> + >> + *bits = 0; > >> + if (*mask & 0xFF0000) > >GENMASK(23, 16) ? > >> + *bits |= (unsigned long)inb(idio16gpio->base + 1) << 16; > >Do you need casting? > >> + if (*mask & 0xFF000000) > >GENMASK(31, 24) ? > >Alternative (and for above): > >(*mask >> 24) & 0xff > >(*mask >> 16) & 0xff That's a good suggestion since GENMASK would be useful in making it clear which bits we are actually checking; the literal bitmasks such as 0xFF000000 can be difficult to read at a glance. I'll incorporate GENMASK into a version 4 release of this patch. > > >> + *bits |= (unsigned long)inb(idio16gpio->base + 5) << 24; > >Do you need casting? The inb function returns a u8, which is typically a typedef of an unsigned char. Since u8 only guaranteed a range of 8 bits, we require a cast to unsigned long to guarantee that the left shifted value stays intact as a 32-bit unsigned value rather than wrap around an 8-bit unsigned range. William Breathitt Gray > >> + >> + return 0; >> +} >> + >> static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value) >> { >> struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); >> @@ -244,6 +258,7 @@ static int idio_16_probe(struct device *dev, unsigned int 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; >> idio16gpio->base = base[id]; >> -- >> 2.16.2 >> > > > >-- >With Best Regards, >Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpio/gpio-104-idio-16.c b/drivers/gpio/gpio-104-idio-16.c index 2f16638a0589..5de5819e5156 100644 --- a/drivers/gpio/gpio-104-idio-16.c +++ b/drivers/gpio/gpio-104-idio-16.c @@ -90,6 +90,20 @@ static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset) return !!(inb(idio16gpio->base + 5) & (mask>>8)); } +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); + + *bits = 0; + if (*mask & 0xFF0000) + *bits |= (unsigned long)inb(idio16gpio->base + 1) << 16; + if (*mask & 0xFF000000) + *bits |= (unsigned long)inb(idio16gpio->base + 5) << 24; + + return 0; +} + static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct idio_16_gpio *const idio16gpio = gpiochip_get_data(chip); @@ -244,6 +258,7 @@ static int idio_16_probe(struct device *dev, unsigned int 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; idio16gpio->base = base[id];
The ACCES I/O 104-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 104-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> --- drivers/gpio/gpio-104-idio-16.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)