summaryrefslogtreecommitdiffstats
path: root/Documentation/mips/ingenic-tcu.rst
diff options
context:
space:
mode:
authorCosta Shulyupin <costa.shul@redhat.com>2023-07-25 06:38:03 +0200
committerJonathan Corbet <corbet@lwn.net>2023-08-18 19:03:52 +0200
commitec62a746b65363f6078fb1eefc7faffe1a4cdc38 (patch)
treef942f375b8ea431c3e7e0bf297b2e7a4685f295b /Documentation/mips/ingenic-tcu.rst
parentdocs: move loongarch under arch (diff)
downloadlinux-ec62a746b65363f6078fb1eefc7faffe1a4cdc38.tar.xz
linux-ec62a746b65363f6078fb1eefc7faffe1a4cdc38.zip
docs: move mips under arch
and fix all in-tree references. Architecture-specific documentation is being moved into Documentation/arch/ as a way of cleaning up the top-level documentation directory and making the docs hierarchy more closely match the source hierarchy. Signed-off-by: Costa Shulyupin <costa.shul@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20230725043835.2249678-1-costa.shul@redhat.com
Diffstat (limited to 'Documentation/mips/ingenic-tcu.rst')
-rw-r--r--Documentation/mips/ingenic-tcu.rst71
1 files changed, 0 insertions, 71 deletions
diff --git a/Documentation/mips/ingenic-tcu.rst b/Documentation/mips/ingenic-tcu.rst
deleted file mode 100644
index 2ce4cb1314dc..000000000000
--- a/Documentation/mips/ingenic-tcu.rst
+++ /dev/null
@@ -1,71 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0
-
-===============================================
-Ingenic JZ47xx SoCs Timer/Counter Unit hardware
-===============================================
-
-The Timer/Counter Unit (TCU) in Ingenic JZ47xx SoCs is a multi-function
-hardware block. It features up to eight channels, that can be used as
-counters, timers, or PWM.
-
-- JZ4725B, JZ4750, JZ4755 only have six TCU channels. The other SoCs all
- have eight channels.
-
-- JZ4725B introduced a separate channel, called Operating System Timer
- (OST). It is a 32-bit programmable timer. On JZ4760B and above, it is
- 64-bit.
-
-- Each one of the TCU channels has its own clock, which can be reparented to three
- different clocks (pclk, ext, rtc), gated, and reclocked, through their TCSR register.
-
- - The watchdog and OST hardware blocks also feature a TCSR register with the same
- format in their register space.
- - The TCU registers used to gate/ungate can also gate/ungate the watchdog and
- OST clocks.
-
-- Each TCU channel works in one of two modes:
-
- - mode TCU1: channels cannot work in sleep mode, but are easier to
- operate.
- - mode TCU2: channels can work in sleep mode, but the operation is a bit
- more complicated than with TCU1 channels.
-
-- The mode of each TCU channel depends on the SoC used:
-
- - On the oldest SoCs (up to JZ4740), all of the eight channels operate in
- TCU1 mode.
- - On JZ4725B, channel 5 operates as TCU2, the others operate as TCU1.
- - On newest SoCs (JZ4750 and above), channels 1-2 operate as TCU2, the
- others operate as TCU1.
-
-- Each channel can generate an interrupt. Some channels share an interrupt
- line, some don't, and this changes between SoC versions:
-
- - on older SoCs (JZ4740 and below), channel 0 and channel 1 have their
- own interrupt line; channels 2-7 share the last interrupt line.
- - On JZ4725B, channel 0 has its own interrupt; channels 1-5 share one
- interrupt line; the OST uses the last interrupt line.
- - on newer SoCs (JZ4750 and above), channel 5 has its own interrupt;
- channels 0-4 and (if eight channels) 6-7 all share one interrupt line;
- the OST uses the last interrupt line.
-
-Implementation
-==============
-
-The functionalities of the TCU hardware are spread across multiple drivers:
-
-=========== =====
-clocks drivers/clk/ingenic/tcu.c
-interrupts drivers/irqchip/irq-ingenic-tcu.c
-timers drivers/clocksource/ingenic-timer.c
-OST drivers/clocksource/ingenic-ost.c
-PWM drivers/pwm/pwm-jz4740.c
-watchdog drivers/watchdog/jz4740_wdt.c
-=========== =====
-
-Because various functionalities of the TCU that belong to different drivers
-and frameworks can be controlled from the same registers, all of these
-drivers access their registers through the same regmap.
-
-For more information regarding the devicetree bindings of the TCU drivers,
-have a look at Documentation/devicetree/bindings/timer/ingenic,tcu.yaml.