Add GPIO support for the Analog Devices AD7768 and AD7768-4
simultaneous sampling ADCs.
Datasheet:
https://www.analog.com/media/en/technical-documentation/data-sheets/ad7768-ad7768-4.pdf
**Device Overview:**
The AD7768 and AD7768-4 provide five on-chip GPIO pins controlled
through registers shared with the parent IIO device. The GPIO driver is
registered as an auxiliary driver and shares the parent's regmap and
runtime power-management state.
**Features Implemented:**
- Use regmap_test_bits() for single-bit gpio-regmap value and direction
reads.
- Add optional runtime PM support to gpio-regmap.
- Expose the five AD7768 GPIO pins through gpio-regmap.
- Read output GPIO values from the output-latch register while retaining
input-state reads for input pins.
- Reserve GPIO4 when it is used to select the crystal or LVDS master
clock source.
**Patch Summary:**
1. Use regmap_test_bits() for single-bit gpio-regmap reads.
2. Add optional runtime PM support to gpio-regmap.
3. Add the AD7768 GPIO auxiliary driver.
**Testing:**
The complete AD7768 driver was compiled and tested on the
EVAL-AD7768FMCZ using a Zedboard with a mainline kernel.
**Base:**
This series is based on the GPIO subsystem's gpio/for-next branch,
commit a2cfc48fee416f0ea78e7dc38acbf2ce072574cc
Signed-off-by: Janani Sunil <janani.sunil@analog.com>
---
Changes in v8:
- Associate the GPIO chip with the AD7768 firmware node and use it for
clock-source property lookup.
- Link to v7: https://lore.kernel.org/r/20260908-ad7768-gpio-v7-0-52ee6ef18a1e@analog.com
Changes in v7:
- Replace bitmap_clear() with __clear_bit() and use bitops.h.
- Initialize the parent device pointer at declaration.
- Link to v6: https://lore.kernel.org/r/20260903-ad7768-gpio-v6-0-4254ef6c9b38@analog.com
Changes in v6:
- Split the GPIO patches from the main AD7768 IIO series.
- Rebase onto gpio/for-next commit
a2cfc48fee416f0ea78e7dc38acbf2ce072574cc.
- Adapt the gpio-regmap callbacks to the operation argument present in
gpio/for-next.
- Align the gpio-regmap runtime-PM member layout with review feedback.
- Move GPIO valid-mask handling into the GPIO driver and reserve GPIO4
there when it is used for crystal or LVDS clock selection.
- Link to v5: https://lore.kernel.org/r/20260828-ad7768-driver-v5-0-e33ca6f841a2@analog.com
---
Janani Sunil (3):
gpio: regmap: Use regmap_test_bits() for single bit reads
gpio: regmap: Add optional runtime PM support
gpio: ad7768: Add AD7768 GPIO auxiliary driver
drivers/gpio/Kconfig | 12 +++++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-ad7768.c | 121 ++++++++++++++++++++++++++++++++++++++++++++
drivers/gpio/gpio-regmap.c | 98 +++++++++++++++++++++++++++++------
include/linux/gpio/regmap.h | 2 +
5 files changed, 219 insertions(+), 15 deletions(-)
---
base-commit: a2cfc48fee416f0ea78e7dc38acbf2ce072574cc
change-id: 20260903-ad7768-gpio-4a19153b1470
Best regards,
--
Janani Sunil <janani.sunil@analog.com>