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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-22 09:30:30 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-22 09:30:30 -0700 |
commit | 5c6bd5de3c2e5bc8a17451e281ed2613375a7fd5 (patch) | |
tree | ec6af5a1dfddef30f92da4a2742bf3da04b520f9 /Documentation/mips | |
parent | f7c3bf8fa7e5a8e45f4a8e82be6466157854b59b (diff) | |
parent | 05d013a0366d50f4f0dbebf8c1b22b42020bf49a (diff) | |
download | linux-5c6bd5de3c2e5bc8a17451e281ed2613375a7fd5.tar.gz linux-5c6bd5de3c2e5bc8a17451e281ed2613375a7fd5.tar.bz2 linux-5c6bd5de3c2e5bc8a17451e281ed2613375a7fd5.zip |
Merge tag 'mips_5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
Pull MIPS updates from Paul Burton:
"Main MIPS changes:
- boot_mem_map is removed, providing a nice cleanup made possible by
the recent removal of bootmem.
- Some fixes to atomics, in general providing compiler barriers for
smp_mb__{before,after}_atomic plus fixes specific to Loongson CPUs
or MIPS32 systems using cmpxchg64().
- Conversion to the new generic VDSO infrastructure courtesy of
Vincenzo Frascino.
- Removal of undefined behavior in set_io_port_base(), fixing the
behavior of some MIPS kernel configurations when built with recent
clang versions.
- Initial MIPS32 huge page support, functional on at least Ingenic
SoCs.
- pte_special() is now supported for some configurations, allowing
among other things generic fast GUP to be used.
- Miscellaneous fixes & cleanups.
And platform specific changes:
- Major improvements to Ingenic SoC support from Paul Cercueil,
mostly enabled by the inclusion of the new TCU (timer-counter unit)
drivers he's spent a very patient year or so working on. Plus some
fixes for X1000 SoCs from Zhou Yanjie.
- Netgear R6200 v1 systems are now supported by the bcm47xx platform.
- DT updates for BMIPS, Lantiq & Microsemi Ocelot systems"
* tag 'mips_5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (89 commits)
MIPS: Detect bad _PFN_SHIFT values
MIPS: Disable pte_special() for MIPS32 with RiXi
MIPS: ralink: deactivate PCI support for SOC_MT7621
mips: compat: vdso: Use legacy syscalls as fallback
MIPS: Drop Loongson _CACHE_* definitions
MIPS: tlbex: Remove cpu_has_local_ebase
MIPS: tlbex: Simplify r3k check
MIPS: Select R3k-style TLB in Kconfig
MIPS: PCI: refactor ioc3 special handling
mips: remove ioremap_cachable
mips/atomic: Fix smp_mb__{before,after}_atomic()
mips/atomic: Fix loongson_llsc_mb() wreckage
mips/atomic: Fix cmpxchg64 barriers
MIPS: Octeon: remove duplicated include from dma-octeon.c
firmware: bcm47xx_nvram: Allow COMPILE_TEST
firmware: bcm47xx_nvram: Correct size_t printf format
MIPS: Treat Loongson Extensions as ASEs
MIPS: Remove dev_err() usage after platform_get_irq()
MIPS: dts: mscc: describe the PTP ready interrupt
MIPS: dts: mscc: describe the PTP register range
...
Diffstat (limited to 'Documentation/mips')
-rw-r--r-- | Documentation/mips/index.rst | 9 | ||||
-rw-r--r-- | Documentation/mips/ingenic-tcu.rst | 71 |
2 files changed, 77 insertions, 3 deletions
diff --git a/Documentation/mips/index.rst b/Documentation/mips/index.rst index fd9023c8a89f..a93c2f65884c 100644 --- a/Documentation/mips/index.rst +++ b/Documentation/mips/index.rst @@ -1,11 +1,14 @@ .. SPDX-License-Identifier: GPL-2.0 -================= -MIPS architecture -================= +=========================== +MIPS-specific Documentation +=========================== .. toctree:: :maxdepth: 2 + :numbered: + + ingenic-tcu au1xxx_ide diff --git a/Documentation/mips/ingenic-tcu.rst b/Documentation/mips/ingenic-tcu.rst new file mode 100644 index 000000000000..c4ef4c45aade --- /dev/null +++ b/Documentation/mips/ingenic-tcu.rst @@ -0,0 +1,71 @@ +.. 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 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/mfd/ingenic,tcu.txt. |