[PATCH v3 0/3] Add RZ/G3L PWRRDY power sequencing support

From: Biju Das <[email protected]>

Hi All,

Some RZ SoCs (e.g. RZ/G3L) have a PWRRDY register that signals power
readiness for various IPs (USB, DSI, CSI, etc.) to their respective
controllers. This register is part of the SYSC IP. Add a dedicated
power sequencing driver to handle these signals.

This series adds that support:

- Patch 1 adds a pwrrdy_pwrseq flag to struct rz_sysc_soc_id_init_data,
  sets it for RZ/G3L, and has the SYSC driver register a
  "pwrseq-pwrrdy" auxiliary device when the flag is set, so a
  dedicated driver can bind to it and handle the sequencing.

- Patch 2 adds that dedicated driver, pwrseq-renesas-pwrrdy, which
  binds to the auxiliary device exposed by patch 1 and exposes
  usb-pwrrdy, dsi-pwrrdy, and csi-pwrrdy pwrseq targets, toggling the
  appropriate bits in the SYS_PWRRDY_N register via the parent SYSC
  driver's regmap.

- Patch 3 selects POWER_SEQUENCING_RENESAS_PWRRDY from
  SYSC_R9A08G046 so the new driver is built whenever RZ/G3L SYSC
  support is enabled.
  
This series is based on proposal for power sequence driver [1]
for USB PWRRDY signal and DSI PWRRDY signal[2].

v2->v3:
 * Updated commit description by dropping devm_add_action_or_reset().
 * Config now selects AUXILIARY_BUS to avoid compilation issues.
 * Dropped the cast in devm_auxiliary_device_create().
 * SYSC_RZ and POWER_SEQUENCING_RENESAS_PWRRDY config selects
   AUXILIARY_BUS to avoid compilation issues.
 * Added match for consumer device and added of_device.h header file.
 * Replaced regmap_update_bits()->regmap_assign_bits() and updated
   the function parameter of pwrseq_rzg3l_set_pwrrdy().
 * Simpilfied probe() return with PTR_ERR_OR_ZERO macro.
 * SYSC_R9A08G046 config selects POWER_SEQUENCING as 
   POWER_SEQUENCING_RENESAS_PWRRDY is defined inside an if
   POWER_SEQUENCING block in drivers/power/sequencing/Kconfig.
v1->v2:
 * Switched to devm_auxiliary_device_create().
 * Added regmap parameter to rz_sysc_pwrrdy_pwrseq_init(),so that regmap
   can be passed as platform data.
 * Added a comment in pwrseq_rzg3l_pwrrdy_match().
 * Dropped dev_get_regmap() from probe as regmap is now part of platform
   data.
 * Added a blank line before devm_pwrseq_device_register() in probe.
 * Dropped the error message devm_pwrseq_device_register() as probe prints
   failure message.
 * Dropped local variables dev and regmap from probe().
 
 [1] https://lore.kernel.org/all/[email protected]/#t
 [2] https://lore.kernel.org/all/[email protected]/T/#mb6f18d8fa9a194fc0a15db5f4938df420da7b6b5

Biju Das (3):
  soc: renesas: rz-sysc: Register auxiliary device for PWRRDY power
    sequencer
  power: sequencing: Add Renesas RZ/G3L Power Ready driver
  soc: renesas: Kconfig: Select POWER_SEQUENCING_RENESAS_PWRRDY for
    R9A08G046

 drivers/power/sequencing/Kconfig              |   9 ++
 drivers/power/sequencing/Makefile             |   1 +
 .../power/sequencing/pwrseq-renesas-pwrrdy.c  | 147 ++++++++++++++++++
 drivers/soc/renesas/Kconfig                   |   3 +
 drivers/soc/renesas/r9a08g046-sysc.c          |   1 +
 drivers/soc/renesas/rz-sysc.c                 |  21 +++
 drivers/soc/renesas/rz-sysc.h                 |   2 +
 7 files changed, 184 insertions(+)
 create mode 100644 drivers/power/sequencing/pwrseq-renesas-pwrrdy.c

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2.43.0