MIPS: CI20: Add efuse driver for Ingenic JZ4780 and attach to DM9000 for stable MAC addresses

* fix a compiler warning/error (reported by Paul Cercueil <[email protected]>)
* remove clock-names from properties (suggested by Paul Cercueil <[email protected]>)

PATCH V7 2020-02-28 14:58:30:
* use devm_add_action_or_reset to unprepare clock in case of error (suggested by Paul Cercueil <[email protected]>)
* use already existing constants to check for overflow of rd_adj and rd_strobe
* remove clock-names from bindings example and DTS (suggested by Paul Cercueil <[email protected]>)
* addition for nemc driver to handle this correctly (contributed by Paul Cercueil <[email protected]>)
* make efuse a child node of nemc to avoid problems with overlapping
reg address ranges (suggested by Paul Cercueil <[email protected]>)

PATCH V6 2020-02-26 12:16:07:
* add dependency on CONFIG_OF and select REGMAP_MMIO (suggested by Paul Cercueil <[email protected]>)
* add clk_prepare_enable() (suggested by Paul Cercueil <[email protected]>)
* inline jz4780_efuse_read_32bytes() since it is only used once
* remove read optimization for full block (suggested by Paul Cercueil <[email protected]>)
* simplify calculations for rd_adj and rd_strobe (suggested by Paul Cercueil <[email protected]>)
* do calculations for rd_adj and rd_strobe in local variables
* fix overflow check (did allow for 5 bit values although register is 4 bit wide)
* fixes for yaml (sugested by Andreas Kemnade <[email protected]>)

PATCH V5 2020-02-22 11:25:35:
* no longer RFC but PATCH
* add yaml bindings (by Andreas Kemnade <[email protected]>)
* fixes to yaml (suggested by Rob Herring <[email protected]>)

RFC V4 2020-02-17 17:55:35:
* removed read_only for nvmem config because there is no write method
* Kconfig: replaced depends MACH_JZ4780 with MACH_INGENIC
* run through checkpatch and fixed issues
* made use of devm_nvram_register() and get rid of jz4780_efuse_remove() (suggested by Srinivas Kandagatla <[email protected]>)
* squashed previous patch 1/9 and 2/9 into single (regmap based) driver

RFC V3 2020-02-16 20:20:59:

This series is based on and a follow up for

https://lore.kernel.org/patchwork/cover/868157/

("[v2,0/2] Add efuse driver for Ingenic JZ4780 SoC")

Original authors were
PrasannaKumar Muralidharan <[email protected]> Mathieu Malaterre <[email protected]>

and there are additions / code improvements by
H. Nikolaus Schaller <[email protected]>
Paul Cercueil <[email protected]>

This setup works, if the dm9000 driver is compiled as a module.

Therefore it is all RFC level. It is also not completely checkpatched.

H. Nikolaus Schaller (1):
MIPS: DTS: CI20: make DM9000 Ethernet controller use NVMEM to find the
default MAC address

Paul Cercueil (1):
memory: jz4780_nemc: Only request IO memory the driver will use

PrasannaKumar Muralidharan (5):
nvmem: add driver for JZ4780 efuse
Bindings: nvmem: add bindings for JZ4780 efuse
Documentation: ABI: nvmem: add documentation for JZ4780 efuse ABI
nvmem: MAINTAINERS: add maintainer for JZ4780 efuse driver
MIPS: DTS: JZ4780: define node for JZ4780 efuse

 .../ABI/testing/sysfs-driver-jz4780-efuse     |  16 ++
 .../bindings/nvmem/ingenic,jz4780-efuse.yaml  |  45 ++++
 MAINTAINERS                                   |   5 +
 arch/mips/boot/dts/ingenic/ci20.dts           |   3 +
 arch/mips/boot/dts/ingenic/jz4780.dtsi        |  19 +-
 drivers/memory/jz4780-nemc.c                  |  15 +-
 drivers/nvmem/Kconfig                         |  12 +
 drivers/nvmem/Makefile                        |   2 +
 drivers/nvmem/jz4780-efuse.c                  | 239 ++++++++++++++++++
 9 files changed, 353 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-jz4780-efuse
 create mode 100644 Documentation/devicetree/bindings/nvmem/ingenic,jz4780-efuse.yaml
 create mode 100644 drivers/nvmem/jz4780-efuse.c

2.23.0