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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-05 14:50:51 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-05 14:50:51 -0700 |
commit | 41844e36206be90cd4d962ea49b0abc3612a99d0 (patch) | |
tree | ce0b3a3403bc6abdb28f52779d0d7b57a51a5c86 /drivers/staging/greybus/timesync_platform.c | |
parent | 5691f0e9a3e7855832d5fd094801bf600347c2d0 (diff) | |
parent | fc1e2c8ea85e109acf09e74789e9b852f6eed251 (diff) | |
download | op-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.zip op-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.tar.gz |
Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging and IIO updates from Greg KH:
"Here is the big staging and IIO driver pull request for 4.9-rc1.
There are a lot of patches in here, the majority due to the
drivers/staging/greybus/ subsystem being merged in with full
development history that went back a few years, in order to preserve
the work that those developers did over time.
Lots and lots of tiny cleanups happened in the tree as well, due to
the Outreachy application process and lots of other developers showing
up for the first time to clean code up. Along with those changes, we
deleted a wireless driver, and added a raspberrypi driver (currently
marked broken), and lots of new iio drivers.
Overall the tree still shrunk with more lines removed than added,
about 10 thousand lines removed in total. Full details are in the very
long shortlog below.
All of this has been in the linux-next tree with no issues. There will
be some merge problems with other subsystem trees, but those are all
minor problems and shouldn't be hard to work out when they happen
(MAINTAINERS and some lustre build problems with the IB tree)"
And furter from me asking for clarification about greybus:
"Right now there is a phone from Motorola shipping with this code (a
slightly older version, but the same tree), so even though Ara is not
alive in the same form, the functionality is happening. We are working
with the developers of that phone to merge the newer stuff in with
their fork so they can use the upstream version in future versions of
their phone product line.
Toshiba has at least one chip shipping in their catalog that
needs/uses this protocol over a Unipro link, and rumor has it that
there might be more in the future.
There are also other users of the greybus protocols, there is a talk
next week at ELC that shows how it is being used across a network
connection to control a device, and previous ELC talks have showed the
protocol stack being used over USB to drive embedded Linux boards.
I've also talked to some people who are starting to work to add a host
controller driver to control arduinos as the greybus PHY protocols are
very useful to control a serial/i2c/spio/whatever device across a
random physical link, as it is a way to have a self-describing device
be attached to a host without needing manual configuration.
So yes, people are using it, and there is still the chance that it
will show up in a phone/laptop/tablet/whatever from Google in the
future as well, the tech isn't dead, even if the original large phone
project happens to be"
* tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits)
Staging: fbtft: Fix bug in fbtft-core
staging: rtl8188eu: fix double unlock error in rtw_resume_process()
staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro
staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro
staging:r8188eu: remove GEN_EVT_CODE macro
staging:r8188eu: remove GEN_CMD_CODE macro
staging:r8188eu: remove pkt_newalloc member of the recv_buf structure
staging:r8188eu: remove rtw_handle_dualmac declaration
staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros
staging:r8188eu: change rtl8188e_process_phy_info function argument type
Staging: fsl-mc: Remove blank lines
Staging: fsl-mc: Fix unaligned * in block comments
Staging: comedi: Align the * in block comments
Staging : ks7010 : Fix block comments warninig
Staging: vt6655: Remove explicit NULL comparison using Coccinelle
staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants
staging: rtl8188eu: core: rtw_xmit: Move constant of the right side
staging: dgnc: Fix lines longer than 80 characters
Staging: dgnc: constify attribute_group structures
Staging: most: hdm-dim2: constify attribute_group structures
...
Diffstat (limited to 'drivers/staging/greybus/timesync_platform.c')
-rw-r--r-- | drivers/staging/greybus/timesync_platform.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/staging/greybus/timesync_platform.c b/drivers/staging/greybus/timesync_platform.c new file mode 100644 index 0000000..113f3d6 --- /dev/null +++ b/drivers/staging/greybus/timesync_platform.c @@ -0,0 +1,82 @@ +/* + * TimeSync API driver. + * + * Copyright 2016 Google Inc. + * Copyright 2016 Linaro Ltd. + * + * Released under the GPLv2 only. + * + * This code reads directly from an ARMv7 memory-mapped timer that lives in + * MMIO space. Since this counter lives inside of MMIO space its shared between + * cores and that means we don't have to worry about issues like TSC on x86 + * where each time-stamp-counter (TSC) is local to a particular core. + * + * Register-level access code is based on + * drivers/clocksource/arm_arch_timer.c + */ +#include <linux/cpufreq.h> +#include <linux/of_platform.h> + +#include "greybus.h" +#include "arche_platform.h" + +#define DEFAULT_FRAMETIME_CLOCK_HZ 19200000 + +static u32 gb_timesync_clock_frequency; +int (*arche_platform_change_state_cb)(enum arche_platform_state state, + struct gb_timesync_svc *pdata); +EXPORT_SYMBOL_GPL(arche_platform_change_state_cb); + +u64 gb_timesync_platform_get_counter(void) +{ + return (u64)get_cycles(); +} + +u32 gb_timesync_platform_get_clock_rate(void) +{ + if (unlikely(!gb_timesync_clock_frequency)) { + gb_timesync_clock_frequency = cpufreq_get(0); + if (!gb_timesync_clock_frequency) + gb_timesync_clock_frequency = DEFAULT_FRAMETIME_CLOCK_HZ; + } + + return gb_timesync_clock_frequency; +} + +int gb_timesync_platform_lock_bus(struct gb_timesync_svc *pdata) +{ + return arche_platform_change_state_cb(ARCHE_PLATFORM_STATE_TIME_SYNC, + pdata); +} + +void gb_timesync_platform_unlock_bus(void) +{ + arche_platform_change_state_cb(ARCHE_PLATFORM_STATE_ACTIVE, NULL); +} + +static const struct of_device_id arch_timer_of_match[] = { + { .compatible = "google,greybus-frame-time-counter", }, + {}, +}; + +int __init gb_timesync_platform_init(void) +{ + struct device_node *np; + + np = of_find_matching_node(NULL, arch_timer_of_match); + if (!np) { + /* Tolerate not finding to allow BBB etc to continue */ + pr_warn("Unable to find a compatible ARMv7 timer\n"); + return 0; + } + + if (of_property_read_u32(np, "clock-frequency", + &gb_timesync_clock_frequency)) { + pr_err("Unable to find timer clock-frequency\n"); + return -ENODEV; + } + + return 0; +} + +void gb_timesync_platform_exit(void) {} |