linux/Documentation
Christophe Roullier 929107d3d2 dt-bindings: net: dwmac: Document STM32 property st,ext-phyclk
The Linux kernel dwmac-stm32 driver currently supports three DT
properties used to configure whether PHY clock are generated by
the MAC or supplied to the MAC from the PHY.

Originally there were two properties, st,eth-clk-sel and
st,eth-ref-clk-sel, each used to configure MAC clocking in
different bus mode and for different MAC clock frequency.
Since it is possible to determine the MAC 'eth-ck' clock
frequency from the clock subsystem and PHY bus mode from
the 'phy-mode' property, two disparate DT properties are
no longer required to configure MAC clocking.

Linux kernel commit 1bb694e208 ("net: ethernet: stmmac: simplify phy modes management for stm32")
introduced a third, unified, property st,ext-phyclk. This property
covers both use cases of st,eth-clk-sel and st,eth-ref-clk-sel DT
properties, as well as a new use case for 25 MHz clock generated
by the MAC.

The third property st,ext-phyclk is so far undocumented,
document it.

Below table summarizes the clock requirement and clock sources for
supported PHY interface modes.
 __________________________________________________________________________
|PHY_MODE | Normal | PHY wo crystal|   PHY wo crystal   |No 125Mhz from PHY|
|         |        |      25MHz    |        50MHz       |                  |

---------------------------------------------------------------------------
|  MII    |    -   |     eth-ck    |        n/a         |       n/a        |
|         |        | st,ext-phyclk |                    |                  |

---------------------------------------------------------------------------
|  GMII   |    -   |     eth-ck    |        n/a         |       n/a        |
|         |        | st,ext-phyclk |                    |                  |

---------------------------------------------------------------------------
| RGMII   |    -   |     eth-ck    |        n/a         |      eth-ck      |
|         |        | st,ext-phyclk |                    | st,eth-clk-sel or|
|         |        |               |                    | st,ext-phyclk    |

---------------------------------------------------------------------------
| RMII    |    -   |     eth-ck    |      eth-ck        |       n/a        |
|         |        | st,ext-phyclk | st,eth-ref-clk-sel |                  |
|         |        |               | or st,ext-phyclk   |                  |

---------------------------------------------------------------------------

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Christophe Roullier <christophe.roullier@foss.st.com>
Link: https://lore.kernel.org/r/20240328185337.332703-2-christophe.roullier@foss.st.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 15:42:11 -07:00
..
ABI Char/Misc and other driver subsystem updates for 6.9-rc1 2024-03-21 13:21:31 -07:00
accel
accounting
admin-guide A handful of late-arriving documentation fixes and enhancements. 2024-03-20 09:36:46 -07:00
arch A set of x86 fixes: 2024-03-24 11:13:56 -07:00
block
bpf bpf, docs: Rename legacy conformance group to packet 2024-03-04 14:31:06 +01:00
cdrom
core-api workqueue: Changes for v6.9 2024-03-11 12:50:42 -07:00
cpu-freq
crypto
dev-tools - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames 2024-03-14 17:43:30 -07:00
devicetree dt-bindings: net: dwmac: Document STM32 property st,ext-phyclk 2024-03-29 15:42:11 -07:00
doc-guide docs: drop the version constraints for sphinx and dependencies 2024-03-03 08:17:20 -07:00
driver-api TTY/Serial driver update for 6.9-rc1 2024-03-21 12:44:10 -07:00
fault-injection
fb
features
filesystems f2fs update for 6.9-rc1 2024-03-18 11:26:00 -07:00
firmware-guide More ACPI updates for 6.9-rc1 2024-03-19 11:15:14 -07:00
firmware_class
fpga
gpu
hid
hwmon hwmon: (aspeed-g6-pwm-tacho): Support for ASPEED g6 PWM/Fan tach 2024-03-07 10:50:16 -08:00
i2c Documentation: i2c: Document that client auto-detection is a legacy mechanism 2024-03-07 09:42:09 +01:00
iio
images
infiniband
input
isdn
kbuild kconfig: remove named choice support 2024-03-10 13:29:48 +09:00
kernel-hacking
leds
litmus-tests
livepatch
locking
maintainer
mhi
misc-devices
mm net: remove gfp_mask from napi_alloc_skb() 2024-03-28 18:30:40 -07:00
netlabel
netlink doc/netlink/specs: Add vlan attr in rt_link spec 2024-03-28 18:07:08 -07:00
networking dns_resolver: correct module name in dns resolver documentation 2024-03-26 10:15:36 +01:00
nvdimm
nvme
PCI
pcmcia
peci
power Documentation: power: Fix typo in suspend and interrupts doc 2024-03-13 20:51:11 +01:00
process A handful of late-arriving documentation fixes and enhancements. 2024-03-20 09:36:46 -07:00
RCU A moderatly busy cycle for development this time around. 2024-03-12 15:18:34 -07:00
rust arm64 updates for 6.9: 2024-03-14 15:35:42 -07:00
scheduler A single update for the documentation of the base_slice_ns tunable to 2024-03-24 11:11:05 -07:00
scsi
security
sound
sphinx docs: drop the version constraints for sphinx and dependencies 2024-03-03 08:17:20 -07:00
sphinx-static
spi spi: docs: spidev: fix echo command format 2024-03-19 18:37:55 +00:00
staging
target
tee
timers
tools tools/rtla: Add -U/--user-load option to timerlat 2024-03-20 05:39:06 +01:00
trace tracing/user_events: Document multi-format flag 2024-03-18 10:13:16 -04:00
translations net: remove gfp_mask from napi_alloc_skb() 2024-03-28 18:30:40 -07:00
usb
userspace-api media updates for v6.9-rc1 2024-03-15 11:36:54 -07:00
virt S390: 2024-03-15 13:03:13 -07:00
w1
watchdog
wmi
.gitignore
atomic_bitops.txt
atomic_t.txt
Changes
CodingStyle
conf.py compiler_types: add Endianness-dependent __counted_by_{le,be} 2024-03-28 18:50:47 -07:00
docutils.conf
dontdiff
index.rst A moderatly busy cycle for development this time around. 2024-03-12 15:18:34 -07:00
Kconfig
Makefile docs: Makefile: Add dependency to $(YNL_INDEX) for targets other than htmldocs 2024-03-05 11:06:43 -07:00
memory-barriers.txt
SubmittingPatches
subsystem-apis.rst