[PATCH v15 0/4] Input: add initial support for Goodix Berlin touchscreen IC

[Neil Armstrong]

These touchscreen ICs support SPI, I2C and I3C interface, up to
10 finger touch, stylus and gestures events.

This initial driver is derived from the Goodix goodix_ts_berlin
available at [1] and [2] and only supports the GT9916 IC
present on the Qualcomm SM8550/SM8650 MTP & QRD touch panel.

The current implementation only supports BerlinD, aka GT9916.

Support for advanced features like:
- Firmware & config update
- Stylus events
- Gestures events
- Previous revisions support (BerlinA or BerlinB)
is not included in current version.

The current support will work with currently flashed firmware
and config, and bail out if firmware or config aren't flashed yet.

[1] https://github.com/goodix/goodix_ts_berlin
[2] https://git.codelinaro.org/clo/la/platform/vendor/opensource/touch-drivers

Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
---
Changes in v15:
- Applied changes/cleanups/fixes provided by Dmitry:
  - Cleanup status/offsets defines, move in to structs
  - Remove packed attribute when not needed
  - Refactor touch data & header structs
  - Store event into goodix_berlin_core
  - simplify goodix_berlin_checksum_valid()
  - simplify goodix_berlin_convert_ic_info() with macro
  - simplify back-and-forth reads with goodix_berlin_get_remaining_contacts()
  - simplify goodix_berlin_touch_handler()
  - cleanup buffer handling comment
  - clear up status field in case of checksum error
- Link to v14: https://lore.kernel.org/r/20231221-topic-goodix-berlin-upstream-initial-v14-0-04459853b640@xxxxxxxxxx

Changes in v14:
- Rebased on next-20231221
- Fixed build on SPI/I2S drivers missing <linux/input.h> include
- Link to v13: https://lore.kernel.org/r/20231213-topic-goodix-berlin-upstream-initial-v13-0-5d7a26a5eaa2@xxxxxxxxxx

Changes in v13:
- Thanks to Dmitry's suggestion:
  - Move core defines and structs into goodix_berlin_core.c
  - Comments typos and rephrasings
  - Identation fixes
  - Refactor of goodix_berlin_power_on
  - goodix_berlin_get_ic_info move to __free(kfree) to avoid leaking
- Added comment explaining how data is retrieved in irq handler
- Link to v12: https://lore.kernel.org/r/20231209-topic-goodix-berlin-upstream-initial-v12-0-eaffaeb53fb5@xxxxxxxxxx

Changes in v12:
- Rebased on next-20231208
- Link to v11: https://lore.kernel.org/r/20231106-topic-goodix-berlin-upstream-initial-v11-0-5c47e9707c03@xxxxxxxxxx

Changes in v11:
- Fixes according to Jeff's review:
 - s/dev_info/dev_err/ in goodix_berlin_get_ic_info()
 - remove spurious return instead of goto in goodix_berlin_get_ic_info()
 - added back dropped msleep() in goodix_berlin_request_handle_reset()
- Link to v10: https://lore.kernel.org/r/20231023-topic-goodix-berlin-upstream-initial-v10-0-88eec2e51c0b@xxxxxxxxxx

Changes in v10:
- Fix according to Dmitry's review:
 - move goodix_berlin_get_ic_info() afe_data to heap
 - merge the goodix_berlin_parse_finger() loops and skip invalid fingers instead of returning
 - remove unwanted goodix_berlin_touch_handler() "static" for buffer
 - only call goodix_berlin_request_handle_reset() if gpio was provided
 - use "error = func(); if(error) return error;" instead of "return func()" when function handles multiple error cases
- Link to v9: https://lore.kernel.org/r/20231021-topic-goodix-berlin-upstream-initial-v9-0-13fb4e887156@xxxxxxxxxx

Changes in v9:
- Rebased on next-20231020 
- Link to v8: https://lore.kernel.org/r/20231003-topic-goodix-berlin-upstream-initial-v8-0-171606102ed6@xxxxxxxxxx

Changes in v8:
- Add missing bitfield.h include in core
- Link to v7: https://lore.kernel.org/r/20231002-topic-goodix-berlin-upstream-initial-v7-0-792fb91f5e88@xxxxxxxxxx

Changes in v7:
- rebased on v6.6-rc3
- Link to v6: https://lore.kernel.org/r/20230912-topic-goodix-berlin-upstream-initial-v6-0-b4ecfa49fb9d@xxxxxxxxxx

Changes in v6:
- rebased on v6.6-rc1
- changed commit message prefix to match the other Input commits
- Link to v5: https://lore.kernel.org/r/20230801-topic-goodix-berlin-upstream-initial-v5-0-079252935593@xxxxxxxxxx

Changes in v5:
- rebased on next-20230801
- Link to v4: https://lore.kernel.org/r/20230606-topic-goodix-berlin-upstream-initial-v4-0-0947c489be17@xxxxxxxxxx

Changes in v4:
- Core updates:
 - drop kconfig depends, deps will be handled by _SPI and _I2C
 - change power_on() error labels
 - print errors on all dev_err() prints
 - remove useless default variable initialization
 - switch irq touch checksum error to dev_err()
 - add Jeff's review tag
- I2C changes
 - change REGMAP_I2C Kconfig from depends to select
 - add Jeff's review tag
- SPI changes
 - add select REGMAP to Kconfig
 - added GOODIX_BERLIN_ prefix to defines
 - switched from ret to error
 - add Jeff's review tag
- Link to v3: https://lore.kernel.org/r/20230606-topic-goodix-berlin-upstream-initial-v3-0-f0577cead709@xxxxxxxxxx

Changes in v3:
- Another guge cleanups after Jeff's review:
 - appended goodix_berlin_ before all defines
 - removed some unused defines
 - removed retries on most of read functions, can be added back later
 - added __le to ic_info structures
 - reworked and simplified irq handling, dropped enum and ts_event structs
 - added struct for touch data
 - simplified and cleaned goodix_berlin_check_checksum & goodix_berlin_is_dummy_data
 - moved touch_data_addr to the end of the main code_data
 - reworked probe to get_irq last and right before setip input device
 - cleaned probe by removing the "cd->dev"
 - added short paragraph to justify new driver for berlin devices
 - defined all offsets & masks
- Added bindings review tag
- Link to v2: https://lore.kernel.org/r/20230606-topic-goodix-berlin-upstream-initial-v2-0-26bc8fe1e90e@xxxxxxxxxx

Changes in v2:
- Huge cleanups after Jeff's review:
 - switch to error instead of ret
 - drop dummy vendor/product ids
 - drop unused defined/enums
 - drop unused ic_info and only keep needes values
 - cleanup namings and use goodix_berlin_ everywhere
 - fix regulator setup
 - fix default variables value when assigned afterwars
 - removed indirections
 - dropped debugfs
 - cleaned input_dev setup
 - dropped _remove()
 - sync'ed i2c and spi drivers
- fixed yaml bindings
- Link to v1: https://lore.kernel.org/r/20230606-topic-goodix-berlin-upstream-initial-v1-0-4a0741b8aefd@xxxxxxxxxx

---
Neil Armstrong (4):
      dt-bindings: input: document Goodix Berlin Touchscreen IC
      Input: add core support for Goodix Berlin Touchscreen IC
      Input: goodix-berlin - add I2C support for Goodix Berlin Touchscreen IC
      Input: goodix-berlin - add SPI support for Goodix Berlin Touchscreen IC

 .../bindings/input/touchscreen/goodix,gt9916.yaml  |  95 +++
 drivers/input/touchscreen/Kconfig                  |  31 +
 drivers/input/touchscreen/Makefile                 |   3 +
 drivers/input/touchscreen/goodix_berlin.h          |  24 +
 drivers/input/touchscreen/goodix_berlin_core.c     | 755 +++++++++++++++++++++
 drivers/input/touchscreen/goodix_berlin_i2c.c      |  75 ++
 drivers/input/touchscreen/goodix_berlin_spi.c      | 178 +++++
 7 files changed, 1161 insertions(+)
---
base-commit: 596764183be8ebb13352b281a442a1f1151c9b06
change-id: 20230606-topic-goodix-berlin-upstream-initial-ba97e8ec8f4c

Best regards,
-- 
Neil Armstrong <neil.armstrong@xxxxxxxxxx>