[PATCH v6 0/2] add mcf54415 DAC driver

[Angelo Dureghello]

This patchset adds a minimalistic DAC driver for the NXP mcf54415/6/7/8
builtin DACs.

Currently the driver enables the raw write only. Feature as dma, sync, or
format are not supoprted for this version.

Additional options suppoerted by the DAC module will be added to the driver
later on, as needed.

The same patchset prepares the m68k/coldfire architecture to support
the driver.

Below some basic tests done on stmark2 mcf54415-based board, voltage check
on DAC0 and DAC1:

~ # cd /sys/bus/iio/devices/iio:device0/
/sys/bus/iio/devices/iio:device0 # ls
name               out_voltage_scale  uevent
out_voltage_raw    subsystem
/sys/bus/iio/devices/iio:device0 # cat name
mcf54415
/sys/bus/iio/devices/iio:device0 # echo 4095 > out_voltage_raw 
/sys/bus/iio/devices/iio:device0 # echo 2048 > out_voltage_raw 
/sys/bus/iio/devices/iio:device0 # echo 4096 > out_voltage_raw 
sh: write error: Invalid argument
/sys/bus/iio/devices/iio:device0 # cat out_voltage_raw 
2048
/sys/bus/iio/devices/iio:device0 # 

Same behavior for /sys/bus/iio/devices/iio:device1.

Generated a sine wave by shell script, sine shape is good.

is actually in progress:

Note: this patchset depends on mew mcf_read/mcf_write implementation that
Link: https://lore.kernel.org/linux-m68k/209d0653-6386-4b64-9e15-e358f84453ab@app.fastmail.com/T/#t
Link: https://lore.kernel.org/linux-m68k/20260506142644.3234270-2-gerg@kernel.org/
---
Changes in v6:
- Removed patches 1 to 8, already pushed in m68knommu for-next by
  Greg Ungerer <gerg at linux-m68k.org>
- keeping changelog in each single patch, where any
- Link to v5: https://patch.msgid.link/20260610-wip-stmark2-dac-v5-0-b76b83366d5c@baylibre.com

Changes in v5:
- keeping changelog in each single patch, where any
- Link to v4: https://patch.msgid.link/20260531-wip-stmark2-dac-v4-0-7e65ab4215dd@baylibre.com

Changes in v4:
- keeping changelog in each single patch, where any
- Link to v3: https://patch.msgid.link/20260522-wip-stmark2-dac-v3-0-16be0ad35a67@baylibre.com

Changes in v3:
- keeping changelog in each single patch, where any
- Link to v2: https://patch.msgid.link/20260513-wip-stmark2-dac-v2-0-fcdae50cf51a@baylibre.com

Changes in v2:
- keeping changelog in each single patch, where any
- Link to v1: https://patch.msgid.link/20260504-wip-stmark2-dac-v1-0-874c36a4910d@baylibre.com

To: Jonathan Cameron <jic23 at kernel.org>
To: David Lechner <dlechner at baylibre.com>
To: Nuno Sá <nuno.sa at analog.com>
To: Andy Shevchenko <andy at kernel.org>
To: Geert Uytterhoeven <geert at linux-m68k.org>
To: Maxime Coquelin <mcoquelin.stm32 at gmail.com>
To: Alexandre Torgue <alexandre.torgue at foss.st.com>
Cc: linux-kernel at vger.kernel.org
Cc: linux-iio at vger.kernel.org
Cc: linux-m68k at lists.linux-m68k.org
Cc: linux-stm32 at st-md-mailman.stormreply.com
Cc: linux-arm-kernel at lists.infradead.org

---
Angelo Dureghello (2):
      iio: dac: add mcf54415 DAC
      m68k: defconfig: update stmark2 defconfig

 arch/m68k/configs/stmark2_defconfig |   2 +
 drivers/iio/dac/Kconfig             |  11 +++
 drivers/iio/dac/Makefile            |   1 +
 drivers/iio/dac/mcf54415_dac.c      | 183 ++++++++++++++++++++++++++++++++++++
 4 files changed, 197 insertions(+)
---
base-commit: d43c76b1fd85cf6f9a53145ed397d10e76f99213
change-id: 20260430-wip-stmark2-dac-7060f49dd94f

Best regards,
--  
Angelo Dureghello <adureghello at baylibre.com>