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25 Commits

Author SHA1 Message Date
Colin Ian King
d036466330 clk: intel: remove redundant initialization of variable rate64 
The variable rate64 is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lkml.kernel.org/r/20200528221219.535804-1-colin.king@canonical.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
 2020-05-28 16:00:33 -07:00
Rahul Tanwar
d058fd9e89 clk: intel: Add CGU clock driver for a new SoC 
Clock Generation Unit(CGU) is a new clock controller IP of a forthcoming
Intel network processor SoC named Lightning Mountain(LGM). It provides
programming interfaces to control & configure all CPU & peripheral clocks.
Add common clock framework based clock controller driver for CGU.

Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Link: https://lkml.kernel.org/r/42a4f71847714df482bacffdcd84341a4052800b.1587102634.git.rahul.tanwar@linux.intel.com
[sboyd@kernel.org: Kill init function to alloc and cleanup newline]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
 2020-05-26 19:58:52 -07:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 
Based on 2 normalized pattern(s):

  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

  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 #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2019-06-19 17:09:55 +02:00
Thomas Gleixner
2025cf9e19 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 263 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2019-06-05 17:36:37 +02:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig 
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 2019-05-21 10:50:46 +02:00
Stephen Boyd
62e59c4e69 clk: Remove io.h from clk-provider.h 
Now that we've gotten rid of clk_readl() we can remove io.h from the
clk-provider header and push out the io.h include to any code that isn't
already including the io.h header but using things like readl/writel,
etc.

Found with this grep:

  git grep -l clk-provider.h | grep '.c$' | xargs git grep -L 'linux/io.h' | \
  	xargs git grep -l \
	-e '\<__iowrite32_copy\>' --or \
	-e '\<__ioread32_copy\>' --or \
	-e '\<__iowrite64_copy\>' --or \
	-e '\<ioremap_page_range\>' --or \
	-e '\<ioremap_huge_init\>' --or \
	-e '\<arch_ioremap_pud_supported\>' --or \
	-e '\<arch_ioremap_pmd_supported\>' --or \
	-e '\<devm_ioport_map\>' --or \
	-e '\<devm_ioport_unmap\>' --or \
	-e '\<IOMEM_ERR_PTR\>' --or \
	-e '\<devm_ioremap\>' --or \
	-e '\<devm_ioremap_nocache\>' --or \
	-e '\<devm_ioremap_wc\>' --or \
	-e '\<devm_iounmap\>' --or \
	-e '\<devm_ioremap_release\>' --or \
	-e '\<devm_memremap\>' --or \
	-e '\<devm_memunmap\>' --or \
	-e '\<__devm_memremap_pages\>' --or \
	-e '\<pci_remap_cfgspace\>' --or \
	-e '\<arch_has_dev_port\>' --or \
	-e '\<arch_phys_wc_add\>' --or \
	-e '\<arch_phys_wc_del\>' --or \
	-e '\<memremap\>' --or \
	-e '\<memunmap\>' --or \
	-e '\<arch_io_reserve_memtype_wc\>' --or \
	-e '\<arch_io_free_memtype_wc\>' --or \
	-e '\<__io_aw\>' --or \
	-e '\<__io_pbw\>' --or \
	-e '\<__io_paw\>' --or \
	-e '\<__io_pbr\>' --or \
	-e '\<__io_par\>' --or \
	-e '\<__raw_readb\>' --or \
	-e '\<__raw_readw\>' --or \
	-e '\<__raw_readl\>' --or \
	-e '\<__raw_readq\>' --or \
	-e '\<__raw_writeb\>' --or \
	-e '\<__raw_writew\>' --or \
	-e '\<__raw_writel\>' --or \
	-e '\<__raw_writeq\>' --or \
	-e '\<readb\>' --or \
	-e '\<readw\>' --or \
	-e '\<readl\>' --or \
	-e '\<readq\>' --or \
	-e '\<writeb\>' --or \
	-e '\<writew\>' --or \
	-e '\<writel\>' --or \
	-e '\<writeq\>' --or \
	-e '\<readb_relaxed\>' --or \
	-e '\<readw_relaxed\>' --or \
	-e '\<readl_relaxed\>' --or \
	-e '\<readq_relaxed\>' --or \
	-e '\<writeb_relaxed\>' --or \
	-e '\<writew_relaxed\>' --or \
	-e '\<writel_relaxed\>' --or \
	-e '\<writeq_relaxed\>' --or \
	-e '\<readsb\>' --or \
	-e '\<readsw\>' --or \
	-e '\<readsl\>' --or \
	-e '\<readsq\>' --or \
	-e '\<writesb\>' --or \
	-e '\<writesw\>' --or \
	-e '\<writesl\>' --or \
	-e '\<writesq\>' --or \
	-e '\<inb\>' --or \
	-e '\<inw\>' --or \
	-e '\<inl\>' --or \
	-e '\<outb\>' --or \
	-e '\<outw\>' --or \
	-e '\<outl\>' --or \
	-e '\<inb_p\>' --or \
	-e '\<inw_p\>' --or \
	-e '\<inl_p\>' --or \
	-e '\<outb_p\>' --or \
	-e '\<outw_p\>' --or \
	-e '\<outl_p\>' --or \
	-e '\<insb\>' --or \
	-e '\<insw\>' --or \
	-e '\<insl\>' --or \
	-e '\<outsb\>' --or \
	-e '\<outsw\>' --or \
	-e '\<outsl\>' --or \
	-e '\<insb_p\>' --or \
	-e '\<insw_p\>' --or \
	-e '\<insl_p\>' --or \
	-e '\<outsb_p\>' --or \
	-e '\<outsw_p\>' --or \
	-e '\<outsl_p\>' --or \
	-e '\<ioread8\>' --or \
	-e '\<ioread16\>' --or \
	-e '\<ioread32\>' --or \
	-e '\<ioread64\>' --or \
	-e '\<iowrite8\>' --or \
	-e '\<iowrite16\>' --or \
	-e '\<iowrite32\>' --or \
	-e '\<iowrite64\>' --or \
	-e '\<ioread16be\>' --or \
	-e '\<ioread32be\>' --or \
	-e '\<ioread64be\>' --or \
	-e '\<iowrite16be\>' --or \
	-e '\<iowrite32be\>' --or \
	-e '\<iowrite64be\>' --or \
	-e '\<ioread8_rep\>' --or \
	-e '\<ioread16_rep\>' --or \
	-e '\<ioread32_rep\>' --or \
	-e '\<ioread64_rep\>' --or \
	-e '\<iowrite8_rep\>' --or \
	-e '\<iowrite16_rep\>' --or \
	-e '\<iowrite32_rep\>' --or \
	-e '\<iowrite64_rep\>' --or \
	-e '\<__io_virt\>' --or \
	-e '\<pci_iounmap\>' --or \
	-e '\<virt_to_phys\>' --or \
	-e '\<phys_to_virt\>' --or \
	-e '\<ioremap_uc\>' --or \
	-e '\<ioremap\>' --or \
	-e '\<__ioremap\>' --or \
	-e '\<iounmap\>' --or \
	-e '\<ioremap\>' --or \
	-e '\<ioremap_nocache\>' --or \
	-e '\<ioremap_uc\>' --or \
	-e '\<ioremap_wc\>' --or \
	-e '\<ioremap_wc\>' --or \
	-e '\<ioremap_wt\>' --or \
	-e '\<ioport_map\>' --or \
	-e '\<ioport_unmap\>' --or \
	-e '\<ioport_map\>' --or \
	-e '\<ioport_unmap\>' --or \
	-e '\<xlate_dev_kmem_ptr\>' --or \
	-e '\<xlate_dev_mem_ptr\>' --or \
	-e '\<unxlate_dev_mem_ptr\>' --or \
	-e '\<virt_to_bus\>' --or \
	-e '\<bus_to_virt\>' --or \
	-e '\<memset_io\>' --or \
	-e '\<memcpy_fromio\>' --or \
	-e '\<memcpy_toio\>'

I also reordered a couple includes when they weren't alphabetical and
removed clk.h from kona, replacing it with clk-provider.h because
that driver doesn't use clk consumer APIs.

Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Acked-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: John Crispin <john@phrozen.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
 2019-05-15 13:21:37 -07:00
David Müller
7c2e071300 clk: x86: Add system specific quirk to mark clocks as critical 
Since commit 648e921888 ("clk: x86: Stop marking clocks as
CLK_IS_CRITICAL"), the pmc_plt_clocks of the Bay Trail SoC are
unconditionally gated off. Unfortunately this will break systems where these
clocks are used for external purposes beyond the kernel's knowledge. Fix it
by implementing a system specific quirk to mark the necessary pmc_plt_clks as
critical.

Fixes: 648e921888 ("clk: x86: Stop marking clocks as CLK_IS_CRITICAL")
Signed-off-by: David Müller <dave.mueller@gmx.ch>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
 2019-04-10 15:54:12 -07:00
Stephen Boyd
75f486c015 Merge branches 'clk-qcom-msm8998', 'clk-fractional-parent', 'clk-x86-mv' and 'clk-SA-fixes' into clk-next 
- Updates for qcom MSM8998 GCC clks
 - qcom MSM8998 RPM managed clks
 - Random static analysis fixes for clk drivers

* clk-qcom-msm8998:
  clk: qcom: Make common clk_hw registrations
  clk: qcom: smd: Add support for MSM8998 rpm clocks
  clk: qcom: Skip halt checks on gcc_usb3_phy_pipe_clk for 8998
  clk: qcom: Add missing freq for usb30_master_clk on 8998
  clk: qcom: Add CLK_SET_RATE_PARENT for 8998 branch clocks

* clk-fractional-parent:
  clk: fractional-divider: check parent rate only if flag is set

* clk-x86-mv:
  clk: x86: Move clk-lpss.h to platform_data/x86

* clk-SA-fixes:
  clk: mediatek: fix platform_no_drv_owner.cocci warnings
  clk: tegra: dfll: Fix debugfs_simple_attr.cocci warnings
  clk: qoriq: Improve an error message
 2019-03-08 10:29:15 -08:00
Andy Shevchenko
a9443a6328 clk: x86: Move clk-lpss.h to platform_data/x86 
clk-lpss.h is solely x86 related header. Move it to correct folder.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
 2019-02-22 00:14:31 -08:00
Matti Vaittinen
d3236214e7 clk: clk-st: avoid clkdev lookup leak at remove 
Use devm based clkdev lookup registration to avoid leaking lookup
structures.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
 2019-02-06 10:35:04 -08:00
Hans de Goede
648e921888 clk: x86: Stop marking clocks as CLK_IS_CRITICAL 
Commit d31fd43c0f ("clk: x86: Do not gate clocks enabled by the
firmware"), which added the code to mark clocks as CLK_IS_CRITICAL, causes
all unclaimed PMC clocks on Cherry Trail devices to be on all the time,
resulting on the device not being able to reach S0i3 when suspended.

The reason for this commit is that on some Bay Trail / Cherry Trail devices
the r8169 ethernet controller uses pmc_plt_clk_4. Now that the clk-pmc-atom
driver exports an "ether_clk" alias for pmc_plt_clk_4 and the r8169 driver
has been modified to get and enable this clock (if present) the marking of
the clocks as CLK_IS_CRITICAL is no longer necessary.

This commit removes the CLK_IS_CRITICAL marking, fixing Cherry Trail
devices not being able to reach S0i3 greatly decreasing their battery
drain when suspended.

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=193891#c102
Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=196861
Cc: Johannes Stezenbach <js@sig21.net>
Cc: Carlo Caione <carlo@endlessm.com>
Reported-by: Johannes Stezenbach <js@sig21.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-09-17 18:47:58 -07:00
Hans de Goede
b1e3454d39 clk: x86: add "ether_clk" alias for Bay Trail / Cherry Trail 
Commit d31fd43c0f ("clk: x86: Do not gate clocks enabled by the
firmware") causes all unclaimed PMC clocks on Cherry Trail devices to be on
all the time, resulting on the device not being able to reach S0i2 or S0i3
when suspended.

The reason for this commit is that on some Bay Trail / Cherry Trail devices
the ethernet controller uses pmc_plt_clk_4. This commit adds an "ether_clk"
alias, so that the relevant ethernet drivers can try to (optionally) use
this, without needing X86 specific code / hacks, thus fixing ethernet on
these devices without breaking S0i3 support.

This commit uses clkdev_hw_create() to create the alias, mirroring the code
for the already existing "mclk" alias for pmc_plt_clk_3.

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=193891#c102
Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=196861
Cc: Johannes Stezenbach <js@sig21.net>
Cc: Carlo Caione <carlo@endlessm.com>
Reported-by: Johannes Stezenbach <js@sig21.net>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2018-09-17 18:47:58 -07:00
Akshu Agrawal
bded6c03e3 clk: x86: Set default parent to 48Mhz 
System clk provided in ST soc can be set to:
48Mhz, non-spread
25Mhz, spread
To get accurate rate, we need it to set it at non-spread
option which is 48Mhz.

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Fixes: 421bf6a1f0 ("clk: x86: Add ST oscout platform clock")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
 2018-08-30 14:47:41 -07:00
Akshu Agrawal
421bf6a1f0 clk: x86: Add ST oscout platform clock 
Stoney SoC provides oscout clock. This clock can support 25Mhz and
48Mhz of frequency.
The clock is available for general system use.

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 2018-05-17 12:44:06 +02:00
Carlo Caione
d31fd43c0f clk: x86: Do not gate clocks enabled by the firmware 
Read the enable register to determine if the clock is already in use by
the firmware. In this case avoid gating the clock.

Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Darren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: Carlo Caione <carlo@endlessm.com>
Fixes: 282a4e4ce5 ("platform/x86: Enable Atom PMC platform clocks")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
 2017-07-18 16:23:13 -07:00
Dan Carpenter
0119dc6132 clk: x86: pmc-atom: Checking for IS_ERR() instead of NULL 
clkdev_hw_create() returns NULLs on error, it doesn't return error
pointers.

Fixes: 41ee7caf59 ("clk: x86: add "mclk" alias for Baytrail/Cherrytrail")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
 2017-05-01 11:13:25 -07:00
Pierre-Louis Bossart
41ee7caf59 clk: x86: add "mclk" alias for Baytrail/Cherrytrail 
Due to timing requirements, TI and Conexant manage the audio
reference clock from their ASoC codec drivers using the "mclk"
string. This patch adds another lookup for the "pmc_plt_clk_3"
clock to avoid Intel-specific tests in those codec drivers and
use code as-is.

To avoid a leak, clk_add_alias() is not used in this patch.
Instead the lookup is created manually as part of the .probe()
step and dropped in the .remove() step.

"pmc_plt_clk_3" is used exclusively for audio on all known
Baytrail/CherryTrail designs and is e.g. routed on the MCLK
(pin 26) of the MinnowBoardMAX Turbot LSE connector.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
 2017-04-19 09:52:32 -07:00
Irina Tirdea
1141d9d081 clk: x86: Add Atom PMC platform clocks 
The BayTrail and CherryTrail platforms provide platform clocks
through their Power Management Controller (PMC).

The SoC supports up to 6 clocks (PMC_PLT_CLK[0..5]) with a
frequency of either 19.2 MHz (PLL) or 25 MHz (XTAL) for BayTrail
and a frequency of 19.2 MHz (XTAL) for CherryTrail. These clocks
are available for general system use, where appropriate, and each
have Control & Frequency register fields associated with them.

Port from legacy by Pierre Bossart, integration in clock framework
by Irina Tirdea

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
 2017-01-26 16:20:46 -08:00
Stephen Boyd
4106684e11 clk: x86: Remove clkdev.h and clk.h includes 
This driver is a clk provider and not a clk consumer, so remove
the clk.h include. Also, drop clkdev.h because there's not clkdev
usage here either.

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
 2016-03-03 11:27:26 -08:00
Stephen Boyd
553b485817 clk: x86: Remove CLK_IS_ROOT 
This flag is a no-op now. Remove usage of the flag.

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
 2016-03-03 11:27:18 -08:00
Wolfram Sang
e030f980b3 clk: x86: drop owner assignment from platform_drivers 
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
 2014-10-20 16:20:23 +02:00
Mika Westerberg
f627217064 ACPI / LPSS: add support for Intel BayTrail 
Intel BayTrail has almost the same Low Power Subsystem than Lynxpoint with
few differences. Peripherals are clocked with different speeds (typically
lower) and the clock is not always gated. To support this we add
possibility to share a common fixed rate clock and make clock gating
optional.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 2013-06-19 01:08:47 +02:00
Rafael J. Wysocki
b59cc200ac ACPI / LPSS: register clock device for Lynxpoint DMA properly 
The DMA controller in Lynxpoint is enumerated as a regular ACPI device now. To
work properly it is using the LPSS root clock as a functional clock. That's why
we have to register the clock device accordingly to the ACPI ID of the DMA
controller. The acpi_lpss.c module is responsible to do the job.

This patch also removes hardcoded name of the DMA device in clk-lpt.c and the
name of the root clock in acpi_lpss.c.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
 2013-05-14 10:23:58 +05:30
Rafael J. Wysocki
f58b082aed ACPI / scan: Add special handler for Intel Lynxpoint LPSS devices 
Devices on the Intel Lynxpoint Low Power Subsystem (LPSS) have some
common features that aren't shared with any other platform devices,
including the clock and LTR (Latency Tolerance Reporting) registers.
It is better to handle those features in common code than to bother
device drivers with doing that (I/O functionality-wise the LPSS
devices are generally compatible with other devices that don't
have those special registers and may be handled by the same drivers).

The clock registers of the LPSS devices are now taken care of by
the special clk-x86-lpss driver, but the MMIO mappings used for
accessing those registers can also be used for accessing the LTR
registers on those devices (LTR support for the Lynxpoint LPSS is
going to be added by a subsequent patch).  Thus it is convenient
to add a special ACPI scan handler for the Lynxpoint LPSS devices
that will create the MMIO mappings for accessing the clock (and
LTR in the future) registers and will register the LPSS devices'
clocks, so the clk-x86-lpss driver will only need to take care of
the main Lynxpoint LPSS clock.

Introduce a special ACPI scan handler for Intel Lynxpoint LPSS
devices as described above.  This also reduces overhead related to
browsing the ACPI namespace in search of the LPSS devices before the
registration of their clocks, removes some LPSS-specific (and
somewhat ugly) code from acpi_platform.c and shrinks the overall code
size slightly.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
 2013-03-21 22:44:38 +01:00
Mika Westerberg
701190fd74 clk: x86: add support for Lynxpoint LPSS clocks 
Intel Lynxpoint Low Power Subsystem hosts peripherals like UART, I2C and
SPI controllers. For most of these there is a configuration register that
allows software to enable and disable the functional clock. Disabling the
clock while the peripheral is not used saves power.

In order to take advantage of this we add a new clock gate of type
lpss_gate that just re-uses the ordinary clk_gate but in addition is able
to enumerate the base address register of the device using ACPI.

We then create a clock tree that models the Lynxpoint LPSS clocks using
these gates and fixed clocks so that we can pass clock rate to the drivers
as well.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 2013-01-23 21:14:22 +01:00