diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 08:57:16 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 08:57:16 -0700 |
commit | 4dc4226f994db264c844a5fcf556935c66f963a5 (patch) | |
tree | 981bf2cb0005c3de8383d749942640d88cb852f2 /drivers/clk | |
parent | d6b92c2c373e0beefa8048c1448992cd5cda6e07 (diff) | |
parent | 2e30baad228624e3868714af6ecab967c4445d4a (diff) |
Merge tag 'pm+acpi-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm into next
Pull ACPI and power management updates from Rafael Wysocki:
"ACPICA is the leader this time (63 commits), followed by cpufreq (28
commits), devfreq (15 commits), system suspend/hibernation (12
commits), ACPI video and ACPI device enumeration (10 commits each).
We have no major new features this time, but there are a few
significant changes of how things work. The most visible one will
probably be that we are now going to create platform devices rather
than PNP devices by default for ACPI device objects with _HID. That
was long overdue and will be really necessary to be able to use the
same drivers for the same hardware blocks on ACPI and DT-based systems
going forward. We're not expecting fallout from this one (as usual),
but it's something to watch nevertheless.
The second change having a chance to be visible is that ACPI video
will now default to using native backlight rather than the ACPI
backlight interface which should generally help systems with broken
Win8 BIOSes. We're hoping that all problems with the native backlight
handling that we had previously have been addressed and we are in a
good enough shape to flip the default, but this change should be easy
enough to revert if need be.
In addition to that, the system suspend core has a new mechanism to
allow runtime-suspended devices to stay suspended throughout system
suspend/resume transitions if some extra conditions are met
(generally, they are related to coordination within device hierarchy).
However, enabling this feature requires cooperation from the bus type
layer and for now it has only been implemented for the ACPI PM domain
(used by ACPI-enumerated platform devices mostly today).
Also, the acpidump utility that was previously shipped as a separate
tool will now be provided by the upstream ACPICA along with the rest
of ACPICA code, which will allow it to be more up to date and better
supported, and we have one new cpuidle driver (ARM clps711x).
The rest is improvements related to certain specific use cases,
cleanups and fixes all over the place.
Specifics:
- ACPICA update to upstream version 20140424. That includes a number
of fixes and improvements related to things like GPE handling,
table loading, headers, memory mapping and unmapping, DSDT/SSDT
overriding, and the Unload() operator. The acpidump utility from
upstream ACPICA is included too. From Bob Moore, Lv Zheng, David
Box, David Binderman, and Colin Ian King.
- Fixes and cleanups related to ACPI video and backlight interfaces
from Hans de Goede. That includes blacklist entries for some new
machines and using native backlight by default.
- ACPI device enumeration changes to create platform devices rather
than PNP devices for ACPI device objects with _HID by default. PNP
devices will still be created for the ACPI device object with
device IDs corresponding to real PNP devices, so that change should
not break things left and right, and we're expecting to see more
and more ACPI-enumerated platform devices in the future. From
Zhang Rui and Rafael J Wysocki.
- Updates for the ACPI LPSS (Low-Power Subsystem) driver allowing it
to handle system suspend/resume on Asus T100 correctly. From
Heikki Krogerus and Rafael J Wysocki.
- PM core update introducing a mechanism to allow runtime-suspended
devices to stay suspended over system suspend/resume transitions if
certain additional conditions related to coordination within device
hierarchy are met. Related PM documentation update and ACPI PM
domain support for the new feature. From Rafael J Wysocki.
- Fixes and improvements related to the "freeze" sleep state. They
affect several places including cpuidle, PM core, ACPI core, and
the ACPI battery driver. From Rafael J Wysocki and Zhang Rui.
- Miscellaneous fixes and updates of the ACPI core from Aaron Lu,
Bjørn Mork, Hanjun Guo, Lan Tianyu, and Rafael J Wysocki.
- Fixes and cleanups for the ACPI processor and ACPI PAD (Processor
Aggregator Device) drivers from Baoquan He, Manuel Schölling, Tony
Camuso, and Toshi Kani.
- System suspend/resume optimization in the ACPI battery driver from
Lan Tianyu.
- OPP (Operating Performance Points) subsystem updates from Chander
Kashyap, Mark Brown, and Nishanth Menon.
- cpufreq core fixes, updates and cleanups from Srivatsa S Bhat,
Stratos Karafotis, and Viresh Kumar.
- Updates, fixes and cleanups for the Tegra, powernow-k8, imx6q,
s5pv210, nforce2, and powernv cpufreq drivers from Brian Norris,
Jingoo Han, Paul Bolle, Philipp Zabel, Stratos Karafotis, and
Viresh Kumar.
- intel_pstate driver fixes and cleanups from Dirk Brandewie, Doug
Smythies, and Stratos Karafotis.
- Enabling the big.LITTLE cpufreq driver on arm64 from Mark Brown.
- Fix for the cpuidle menu governor from Chander Kashyap.
- New ARM clps711x cpuidle driver from Alexander Shiyan.
- Hibernate core fixes and cleanups from Chen Gang, Dan Carpenter,
Fabian Frederick, Pali Rohár, and Sebastian Capella.
- Intel RAPL (Running Average Power Limit) driver updates from Jacob
Pan.
- PNP subsystem updates from Bjorn Helgaas and Fabian Frederick.
- devfreq core updates from Chanwoo Choi and Paul Bolle.
- devfreq updates for exynos4 and exynos5 from Chanwoo Choi and
Bartlomiej Zolnierkiewicz.
- turbostat tool fix from Jean Delvare.
- cpupower tool updates from Prarit Bhargava, Ramkumar Ramachandra
and Thomas Renninger.
- New ACPI ec_access.c tool for poking at the EC in a safe way from
Thomas Renninger"
* tag 'pm+acpi-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (187 commits)
ACPICA: Namespace: Remove _PRP method support.
intel_pstate: Improve initial busy calculation
intel_pstate: add sample time scaling
intel_pstate: Correct rounding in busy calculation
intel_pstate: Remove C0 tracking
PM / hibernate: fixed typo in comment
ACPI: Fix x86 regression related to early mapping size limitation
ACPICA: Tables: Add mechanism to control early table checksum verification.
ACPI / scan: use platform bus type by default for _HID enumeration
ACPI / scan: always register ACPI LPSS scan handler
ACPI / scan: always register memory hotplug scan handler
ACPI / scan: always register container scan handler
ACPI / scan: Change the meaning of missing .attach() in scan handlers
ACPI / scan: introduce platform_id device PNP type flag
ACPI / scan: drop unsupported serial IDs from PNP ACPI scan handler ID list
ACPI / scan: drop IDs that do not comply with the ACPI PNP ID rule
ACPI / PNP: use device ID list for PNPACPI device enumeration
ACPI / scan: .match() callback for ACPI scan handlers
ACPI / battery: wakeup the system only when necessary
power_supply: allow power supply devices registered w/o wakeup source
...
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/Makefile | 1 | ||||
-rw-r--r-- | drivers/clk/clk-fractional-divider.c | 135 |
2 files changed, 136 insertions, 0 deletions
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 17d7f13d19a5..50b2a7ebd747 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_COMMON_CLK) += clk-fixed-rate.o obj-$(CONFIG_COMMON_CLK) += clk-gate.o obj-$(CONFIG_COMMON_CLK) += clk-mux.o obj-$(CONFIG_COMMON_CLK) += clk-composite.o +obj-$(CONFIG_COMMON_CLK) += clk-fractional-divider.o # hardware specific clock types # please keep this section sorted lexicographically by file/directory path name diff --git a/drivers/clk/clk-fractional-divider.c b/drivers/clk/clk-fractional-divider.c new file mode 100644 index 000000000000..ede685ca0d20 --- /dev/null +++ b/drivers/clk/clk-fractional-divider.c @@ -0,0 +1,135 @@ +/* + * Copyright (C) 2014 Intel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Adjustable fractional divider clock implementation. + * Output rate = (m / n) * parent_rate. + */ + +#include <linux/clk-provider.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/gcd.h> + +#define to_clk_fd(_hw) container_of(_hw, struct clk_fractional_divider, hw) + +static unsigned long clk_fd_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_fractional_divider *fd = to_clk_fd(hw); + unsigned long flags = 0; + u32 val, m, n; + u64 ret; + + if (fd->lock) + spin_lock_irqsave(fd->lock, flags); + + val = clk_readl(fd->reg); + + if (fd->lock) + spin_unlock_irqrestore(fd->lock, flags); + + m = (val & fd->mmask) >> fd->mshift; + n = (val & fd->nmask) >> fd->nshift; + + ret = parent_rate * m; + do_div(ret, n); + + return ret; +} + +static long clk_fd_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct clk_fractional_divider *fd = to_clk_fd(hw); + unsigned maxn = (fd->nmask >> fd->nshift) + 1; + unsigned div; + + if (!rate || rate >= *prate) + return *prate; + + div = gcd(*prate, rate); + + while ((*prate / div) > maxn) { + div <<= 1; + rate <<= 1; + } + + return rate; +} + +static int clk_fd_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_fractional_divider *fd = to_clk_fd(hw); + unsigned long flags = 0; + unsigned long div; + unsigned n, m; + u32 val; + + div = gcd(parent_rate, rate); + m = rate / div; + n = parent_rate / div; + + if (fd->lock) + spin_lock_irqsave(fd->lock, flags); + + val = clk_readl(fd->reg); + val &= ~(fd->mmask | fd->nmask); + val |= (m << fd->mshift) | (n << fd->nshift); + clk_writel(val, fd->reg); + + if (fd->lock) + spin_unlock_irqrestore(fd->lock, flags); + + return 0; +} + +const struct clk_ops clk_fractional_divider_ops = { + .recalc_rate = clk_fd_recalc_rate, + .round_rate = clk_fd_round_rate, + .set_rate = clk_fd_set_rate, +}; +EXPORT_SYMBOL_GPL(clk_fractional_divider_ops); + +struct clk *clk_register_fractional_divider(struct device *dev, + const char *name, const char *parent_name, unsigned long flags, + void __iomem *reg, u8 mshift, u8 mwidth, u8 nshift, u8 nwidth, + u8 clk_divider_flags, spinlock_t *lock) +{ + struct clk_fractional_divider *fd; + struct clk_init_data init; + struct clk *clk; + + fd = kzalloc(sizeof(*fd), GFP_KERNEL); + if (!fd) { + dev_err(dev, "could not allocate fractional divider clk\n"); + return ERR_PTR(-ENOMEM); + } + + init.name = name; + init.ops = &clk_fractional_divider_ops; + init.flags = flags | CLK_IS_BASIC; + init.parent_names = parent_name ? &parent_name : NULL; + init.num_parents = parent_name ? 1 : 0; + + fd->reg = reg; + fd->mshift = mshift; + fd->mmask = (BIT(mwidth) - 1) << mshift; + fd->nshift = nshift; + fd->nmask = (BIT(nwidth) - 1) << nshift; + fd->flags = clk_divider_flags; + fd->lock = lock; + fd->hw.init = &init; + + clk = clk_register(dev, &fd->hw); + if (IS_ERR(clk)) + kfree(fd); + + return clk; +} +EXPORT_SYMBOL_GPL(clk_register_fractional_divider); |