Changes in v2:
- Add missing bitmap.h header includes
- Fix typographical error in symbol name for word_mask
- Remove const qualifier for ports array
This patchset implements get_multiple callbacks for the PC104 GPIO
drivers as well as the PCI-IDIO-16 and PCIe-IDIO-24 GPIO drivers. These
devices all acquire the multiple input lines with a single read, so
utilizing the get_multiple callback can provide improvement for those
users who regularly access multiple input lines.
While developing this patchset I noticed many of these devices make use
of Intel 8255 compatible interfaces for their I/O. I may write a generic
8255 GPIO driver in the future to reduce some of the redundant code I
see pop among the drivers for these devices.
William Breathitt Gray (8):
iio: stx104: Implement get_multiple callback
gpio: 104-idio-16: Implement get_multiple callback
gpio: pci-idio-16: Implement get_multiple callback
gpio: pcie-idio-24: Implement get_multiple/set_multiple callbacks
gpio: 104-dio-48e: Implement get_multiple callback
gpio: 104-idi-48: Implement get_multiple callback
gpio: gpio-mm: Implement get_multiple callback
gpio: ws16c48: Implement get_multiple callback
drivers/gpio/gpio-104-dio-48e.c | 47 ++++++++++++++++
drivers/gpio/gpio-104-idi-48.c | 47 ++++++++++++++++
drivers/gpio/gpio-104-idio-16.c | 15 +++++
drivers/gpio/gpio-gpio-mm.c | 47 ++++++++++++++++
drivers/gpio/gpio-pci-idio-16.c | 50 +++++++++++++++++
drivers/gpio/gpio-pcie-idio-24.c | 117 +++++++++++++++++++++++++++++++++++++++
drivers/gpio/gpio-ws16c48.c | 47 ++++++++++++++++
drivers/iio/adc/stx104.c | 11 ++++
8 files changed, 381 insertions(+)
--
2.16.2
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 <[email protected]>
---
drivers/gpio/gpio-104-idio-16.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
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];
--
2.16.2
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 <[email protected]>
---
drivers/gpio/gpio-pci-idio-16.c | 50 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
diff --git a/drivers/gpio/gpio-pci-idio-16.c b/drivers/gpio/gpio-pci-idio-16.c
index 57d1b7fbf07b..f273cf776cac 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, 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;
--
2.16.2
The Apex Embedded Systems STX104 series of devices provides 4 TTL
compatible lines of inputs accessed via a single 4-bit port. Since four
input lines are acquired on a single port input read, the STX104 GPIO
driver may improve multiple input reads by utilizing a get_multiple
callback. This patch implements the stx104_gpio_get_multiple function
which serves as the respective get_multiple callback.
Cc: Jonathan Cameron <[email protected]>
Cc: Hartmut Knaack <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Cc: Peter Meerwald-Stadler <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
---
drivers/iio/adc/stx104.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/iio/adc/stx104.c b/drivers/iio/adc/stx104.c
index 17b021f33180..0662ca199eb0 100644
--- a/drivers/iio/adc/stx104.c
+++ b/drivers/iio/adc/stx104.c
@@ -233,6 +233,16 @@ static int stx104_gpio_get(struct gpio_chip *chip, unsigned int offset)
return !!(inb(stx104gpio->base) & BIT(offset));
}
+static int stx104_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+ unsigned long *bits)
+{
+ struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip);
+
+ *bits = inb(stx104gpio->base);
+
+ return 0;
+}
+
static void stx104_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
@@ -342,6 +352,7 @@ static int stx104_probe(struct device *dev, unsigned int id)
stx104gpio->chip.direction_input = stx104_gpio_direction_input;
stx104gpio->chip.direction_output = stx104_gpio_direction_output;
stx104gpio->chip.get = stx104_gpio_get;
+ stx104gpio->chip.get_multiple = stx104_gpio_get_multiple;
stx104gpio->chip.set = stx104_gpio_set;
stx104gpio->chip.set_multiple = stx104_gpio_set_multiple;
stx104gpio->base = base[id] + 3;
--
2.16.2
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 <[email protected]>
---
drivers/gpio/gpio-pcie-idio-24.c | 117 +++++++++++++++++++++++++++++++++++++++
1 file changed, 117 insertions(+)
diff --git a/drivers/gpio/gpio-pcie-idio-24.c b/drivers/gpio/gpio-pcie-idio-24.c
index f666e2e69074..412aca253c76 100644
--- a/drivers/gpio/gpio-pcie-idio-24.c
+++ b/drivers/gpio/gpio-pcie-idio-24.c
@@ -15,6 +15,7 @@
* This driver supports the following ACCES devices: PCIe-IDIO-24,
* PCIe-IDI-24, PCIe-IDO-24, and PCIe-IDIO-12.
*/
+#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/errno.h>
@@ -193,6 +194,61 @@ static int idio_24_gpio_get(struct gpio_chip *chip, unsigned int offset)
return !!(ioread8(&idio24gpio->reg->ttl_in0_7) & offset_mask);
}
+static int idio_24_gpio_get_multiple(struct gpio_chip *chip,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct idio_24_gpio *const idio24gpio = 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, 0);
+ unsigned long port_state;
+ u8 __iomem ports[] = {
+ idio24gpio->reg->out0_7, idio24gpio->reg->out8_15,
+ idio24gpio->reg->out16_23, idio24gpio->reg->in0_7,
+ idio24gpio->reg->in8_15, idio24gpio->reg->in16_23
+ };
+ const unsigned long out_mode_mask = BIT(1);
+
+ /* 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 6 is TTL GPIO) */
+ if (i < 6)
+ port_state = ioread8(ports + i);
+ else if (ioread8(&idio24gpio->reg->ctl) & out_mode_mask)
+ port_state = ioread8(&idio24gpio->reg->ttl_out0_7);
+ else
+ port_state = ioread8(&idio24gpio->reg->ttl_in0_7);
+
+ /* store acquired bits at respective bits array offset */
+ bits[word_index] |= port_state << word_offset;
+ }
+
+ return 0;
+}
+
static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
@@ -234,6 +290,65 @@ static void idio_24_gpio_set(struct gpio_chip *chip, unsigned int offset,
raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
}
+static void idio_24_gpio_set_multiple(struct gpio_chip *chip,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct idio_24_gpio *const idio24gpio = gpiochip_get_data(chip);
+ size_t i;
+ unsigned long bits_offset;
+ unsigned long gpio_mask;
+ const unsigned int gpio_reg_size = 8;
+ const unsigned long port_mask = GENMASK(gpio_reg_size, 0);
+ unsigned long flags;
+ unsigned int out_state;
+ u8 __iomem ports[] = {
+ idio24gpio->reg->out0_7, idio24gpio->reg->out8_15,
+ idio24gpio->reg->out16_23
+ };
+ const unsigned long out_mode_mask = BIT(1);
+ const unsigned int ttl_offset = 48;
+ const size_t ttl_i = BIT_WORD(ttl_offset);
+ const unsigned int word_offset = ttl_offset % BITS_PER_LONG;
+ const unsigned long ttl_mask = (mask[ttl_i] >> word_offset) & port_mask;
+ const unsigned long ttl_bits = (bits[ttl_i] >> word_offset) & ttl_mask;
+
+ /* set bits are processed 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;
+
+ /* check if any set bits for current port */
+ gpio_mask = (*mask >> bits_offset) & port_mask;
+ if (!gpio_mask) {
+ /* no set bits for this port so move on to next port */
+ continue;
+ }
+
+ raw_spin_lock_irqsave(&idio24gpio->lock, flags);
+
+ /* process output lines */
+ out_state = ioread8(ports + i) & ~gpio_mask;
+ out_state |= (*bits >> bits_offset) & gpio_mask;
+ iowrite8(out_state, ports + i);
+
+ raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+ }
+
+ /* check if setting TTL lines and if they are in output mode */
+ if (!ttl_mask || !(ioread8(&idio24gpio->reg->ctl) & out_mode_mask))
+ return;
+
+ /* handle TTL output */
+ raw_spin_lock_irqsave(&idio24gpio->lock, flags);
+
+ /* process output lines */
+ out_state = ioread8(&idio24gpio->reg->ttl_out0_7) & ~ttl_mask;
+ out_state |= ttl_bits;
+ iowrite8(out_state, &idio24gpio->reg->ttl_out0_7);
+
+ raw_spin_unlock_irqrestore(&idio24gpio->lock, flags);
+}
+
static void idio_24_irq_ack(struct irq_data *data)
{
}
@@ -397,7 +512,9 @@ static int idio_24_probe(struct pci_dev *pdev, const struct pci_device_id *id)
idio24gpio->chip.direction_input = idio_24_gpio_direction_input;
idio24gpio->chip.direction_output = idio_24_gpio_direction_output;
idio24gpio->chip.get = idio_24_gpio_get;
+ idio24gpio->chip.get_multiple = idio_24_gpio_get_multiple;
idio24gpio->chip.set = idio_24_gpio_set;
+ idio24gpio->chip.set_multiple = idio_24_gpio_set_multiple;
raw_spin_lock_init(&idio24gpio->lock);
--
2.16.2
The ACCES I/O 104-DIO-48E series of devices contain two Programmable
Peripheral Interface (PPI) chips of type 82C55, which each feature three
8-bit ports of I/O. Since eight input lines are acquired on a single
port input read, the 104-DIO-48E GPIO driver may improve multiple input
reads by utilizing a get_multiple callback. This patch implements the
dio48e_gpio_get_multiple function which serves as the respective
get_multiple callback.
Signed-off-by: William Breathitt Gray <[email protected]>
---
drivers/gpio/gpio-104-dio-48e.c | 47 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
index bab3b94c5cbc..7d43c77364db 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -14,6 +14,7 @@
* This driver supports the following ACCES devices: 104-DIO-48E and
* 104-DIO-24E.
*/
+#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/errno.h>
@@ -182,6 +183,51 @@ static int dio48e_gpio_get(struct gpio_chip *chip, unsigned offset)
return !!(port_state & mask);
}
+static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+ unsigned long *bits)
+{
+ struct dio48e_gpio *const dio48egpio = 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, 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(dio48egpio->base + ports[i]);
+
+ /* store acquired bits at respective bits array offset */
+ bits[word_index] |= port_state << word_offset;
+ }
+
+ return 0;
+}
+
static void dio48e_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
@@ -384,6 +430,7 @@ static int dio48e_probe(struct device *dev, unsigned int id)
dio48egpio->chip.direction_input = dio48e_gpio_direction_input;
dio48egpio->chip.direction_output = dio48e_gpio_direction_output;
dio48egpio->chip.get = dio48e_gpio_get;
+ dio48egpio->chip.get_multiple = dio48e_gpio_get_multiple;
dio48egpio->chip.set = dio48e_gpio_set;
dio48egpio->chip.set_multiple = dio48e_gpio_set_multiple;
dio48egpio->base = base[id];
--
2.16.2
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 <[email protected]>
---
drivers/gpio/gpio-104-idi-48.c | 47 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
index add859d59766..2c230415eeba 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 <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/errno.h>
@@ -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, 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);
--
2.16.2
The Diamond Systems GPIO-MM series of devices contain two 82C55A
devices, which each feature three 8-bit ports of I/O. Since eight input
lines are acquired on a single port input read, the GPIO-MM GPIO driver
may improve multiple input reads by utilizing a get_multiple callback.
This patch implements the gpiomm_gpio_get_multiple function which serves
as the respective get_multiple callback.
Signed-off-by: William Breathitt Gray <[email protected]>
---
drivers/gpio/gpio-gpio-mm.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c
index 11ade5b288f8..94b86fca65ba 100644
--- a/drivers/gpio/gpio-gpio-mm.c
+++ b/drivers/gpio/gpio-gpio-mm.c
@@ -14,6 +14,7 @@
* This driver supports the following Diamond Systems devices: GPIO-MM and
* GPIO-MM-12.
*/
+#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/errno.h>
@@ -171,6 +172,51 @@ static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset)
return !!(port_state & mask);
}
+static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+ unsigned long *bits)
+{
+ struct gpiomm_gpio *const gpiommgpio = 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, 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(gpiommgpio->base + ports[i]);
+
+ /* store acquired bits at respective bits array offset */
+ bits[word_index] |= port_state << word_offset;
+ }
+
+ return 0;
+}
+
static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
@@ -268,6 +314,7 @@ static int gpiomm_probe(struct device *dev, unsigned int id)
gpiommgpio->chip.direction_input = gpiomm_gpio_direction_input;
gpiommgpio->chip.direction_output = gpiomm_gpio_direction_output;
gpiommgpio->chip.get = gpiomm_gpio_get;
+ gpiommgpio->chip.get_multiple = gpiomm_gpio_get_multiple;
gpiommgpio->chip.set = gpiomm_gpio_set;
gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple;
gpiommgpio->base = base[id];
--
2.16.2
The WinSystems WS16C48 device provides 48 lines of digital I/O accessed
via six 8-bit ports. Since eight input lines are acquired on a single
port input read, the WS16C48 GPIO driver may improve multiple input
reads by utilizing a get_multiple callback. This patch implements the
ws16c48_gpio_get_multiple function which serves as the respective
get_multiple callback.
Signed-off-by: William Breathitt Gray <[email protected]>
---
drivers/gpio/gpio-ws16c48.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c
index 746648244bf3..10525367aa6f 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, 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];
--
2.16.2
On Sat, 17 Mar 2018 11:49:56 -0400
William Breathitt Gray <[email protected]> wrote:
> The Apex Embedded Systems STX104 series of devices provides 4 TTL
> compatible lines of inputs accessed via a single 4-bit port. Since four
> input lines are acquired on a single port input read, the STX104 GPIO
> driver may improve multiple input reads by utilizing a get_multiple
> callback. This patch implements the stx104_gpio_get_multiple function
> which serves as the respective get_multiple callback.
>
> Cc: Jonathan Cameron <[email protected]>
> Cc: Hartmut Knaack <[email protected]>
> Cc: Lars-Peter Clausen <[email protected]>
> Cc: Peter Meerwald-Stadler <[email protected]>
> Signed-off-by: William Breathitt Gray <[email protected]>
This one is simple so applied to the togreg branch of iio.git and pushed
out as testing for the autobuilders to play with it.
Thanks,
Jonathan
> ---
> drivers/iio/adc/stx104.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/iio/adc/stx104.c b/drivers/iio/adc/stx104.c
> index 17b021f33180..0662ca199eb0 100644
> --- a/drivers/iio/adc/stx104.c
> +++ b/drivers/iio/adc/stx104.c
> @@ -233,6 +233,16 @@ static int stx104_gpio_get(struct gpio_chip *chip, unsigned int offset)
> return !!(inb(stx104gpio->base) & BIT(offset));
> }
>
> +static int stx104_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
> + unsigned long *bits)
> +{
> + struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip);
> +
> + *bits = inb(stx104gpio->base);
> +
> + return 0;
> +}
> +
> static void stx104_gpio_set(struct gpio_chip *chip, unsigned int offset,
> int value)
> {
> @@ -342,6 +352,7 @@ static int stx104_probe(struct device *dev, unsigned int id)
> stx104gpio->chip.direction_input = stx104_gpio_direction_input;
> stx104gpio->chip.direction_output = stx104_gpio_direction_output;
> stx104gpio->chip.get = stx104_gpio_get;
> + stx104gpio->chip.get_multiple = stx104_gpio_get_multiple;
> stx104gpio->chip.set = stx104_gpio_set;
> stx104gpio->chip.set_multiple = stx104_gpio_set_multiple;
> stx104gpio->base = base[id] + 3;
On Sat, Mar 17, 2018 at 5:49 PM, William Breathitt Gray
<[email protected]> wrote:
> The Apex Embedded Systems STX104 series of devices provides 4 TTL
> compatible lines of inputs accessed via a single 4-bit port. Since four
> input lines are acquired on a single port input read, the STX104 GPIO
> driver may improve multiple input reads by utilizing a get_multiple
> callback. This patch implements the stx104_gpio_get_multiple function
> which serves as the respective get_multiple callback.
> +static int stx104_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
> + unsigned long *bits)
> +{
> + struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip);
> +
> + *bits = inb(stx104gpio->base);
I think on LE and BE if will give you different results.
> +
> + return 0;
> +}
--
With Best Regards,
Andy Shevchenko
On Sat, Mar 17, 2018 at 08:51:07PM +0200, Andy Shevchenko wrote:
>On Sat, Mar 17, 2018 at 5:49 PM, William Breathitt Gray
><[email protected]> wrote:
>> The Apex Embedded Systems STX104 series of devices provides 4 TTL
>> compatible lines of inputs accessed via a single 4-bit port. Since four
>> input lines are acquired on a single port input read, the STX104 GPIO
>> driver may improve multiple input reads by utilizing a get_multiple
>> callback. This patch implements the stx104_gpio_get_multiple function
>> which serves as the respective get_multiple callback.
>
>> +static int stx104_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
>> + unsigned long *bits)
>> +{
>> + struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip);
>> +
>
>> + *bits = inb(stx104gpio->base);
>
>I think on LE and BE if will give you different results.
That may be true for a memcpy operation, but in this case I'm relying on
the standard C evaluation rules. I expect we should be fine with the
returned byte assigned to an unsigned long, since it'll be evaluated by
its value rather than memory representation.
William Breathitt Gray
>
>> +
>> + return 0;
>> +}
>
>
>
>--
>With Best Regards,
>Andy Shevchenko
On Sat, Mar 17, 2018 at 5:50 PM, William Breathitt Gray
<[email protected]> 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
>
--
With Best Regards,
Andy Shevchenko
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
><[email protected]> 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
On Sat, Mar 17, 2018 at 5:50 PM, William Breathitt Gray
<[email protected]> wrote:
> 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.
> +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, 0);
gpio_reg_size - 1?
Though I would prefer not to have that variable at all, just use 8 or
7 respectively.
> + unsigned long port_state;
> + u8 __iomem ports[] = {
> + idio16gpio->reg->out0_7, idio16gpio->reg->out8_15,
> + idio16gpio->reg->in0_7, idio16gpio->reg->in8_15
I would leave comma even here.
> + };
> + /* 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;
> + }
I would propose to do other way around, i.e.
read all ports to the bitmap array and call bitmap_and() after.
Further optimization can be something like introduction of generic
bitmap_copy_uXX_off(unsigned long *dst, u8 src, unsigned int offset);
It can be done using macros, though it's another story not quite
related to the topic.
> +}
--
With Best Regards,
Andy Shevchenko
On Wed, Mar 21, 2018 at 07:45:29PM +0200, Andy Shevchenko wrote:
>On Sat, Mar 17, 2018 at 5:50 PM, William Breathitt Gray
><[email protected]> wrote:
>> 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.
>
>> +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, 0);
>
>gpio_reg_size - 1?
Oops, looks like I made an off-by-one error here so I'll make sure to
fix that up.
>Though I would prefer not to have that variable at all, just use 8 or
>7 respectively.
This device is simple enough that throughout this function I could
inline gpio_reg_size and port_mask to 8 and 0xFF respectively, but I
would like to keep the code generic enough for reuse in other drivers.
In addition, I believe the variable names help keep the intention of the
code clear, so I'll stick with dedicated const variables for now if
there are no other objections.
>
>> + unsigned long port_state;
>
>> + u8 __iomem ports[] = {
>> + idio16gpio->reg->out0_7, idio16gpio->reg->out8_15,
>
>> + idio16gpio->reg->in0_7, idio16gpio->reg->in8_15
>
>I would leave comma even here.
Will do.
>
>> + };
>
>> + /* 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;
>> + }
>
>I would propose to do other way around, i.e.
>read all ports to the bitmap array and call bitmap_and() after.
>
>Further optimization can be something like introduction of generic
>
>bitmap_copy_uXX_off(unsigned long *dst, u8 src, unsigned int offset);
>
>It can be done using macros, though it's another story not quite
>related to the topic.
Port I/O is significantly more costly to perform than the bitmask
evaluations for each port. Despite the increased complexity of the loop
logic, I believe the latency improvements of skipping unnecessary I/O
port reads are worth the trouble.
I do like the idea of a bitmap_copy_uXX_off macro as that could be quite
useful in general. Even if not for this particular patchset, I would be
interested in seeing that functionality added to the bitmap API. Perhaps
I might implement it as a standlone patch when I have some free time.
William Breathitt Gray
>
>> +}
>
>--
>With Best Regards,
>Andy Shevchenko