Commit Graph

31 Commits

Author SHA1 Message Date
Andy Shevchenko
c1ab111e62 clk: fractional-divider: Use bit operations consistently
Use BIT() where makes sense. This alings usage of bit operations
in the same pieces of code. Moreover, strictly speaking by the
letter of the C standard, left shift of 1 by 31 bits is UB (undefined
behaviour), switching to BIT() addresses that as well.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240303120732.240355-1-andy.shevchenko@gmail.com
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2024-03-08 17:07:11 -08:00
Andy Shevchenko
6e3f07f9df clk: fractional-divider: Move mask calculations out of lock
There is no need to calculate masks under the lock taken.
Move them out of it.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20240303121410.240761-1-andy.shevchenko@gmail.com
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2024-03-08 17:04:04 -08:00
Frank Oltmanns
2e9abc6ec1 clk: fractional-divider: Improve approximation when zero based and export
Consider the CLK_FRAC_DIVIDER_ZERO_BASED flag when finding the best
approximation for m and n. By doing so, increase the range of valid
values for the numerator and denominator by 1.

Furthermore, export the approximation function so that users of this
function can be compiled as modules.

Cc: A.s. Dong <aisheng.dong@nxp.com>
Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
Link: https://lore.kernel.org/r/20230617131041.18313-2-frank@oltmanns.dev
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2023-10-12 14:02:17 -07:00
Christophe JAILLET
141b3251c5 clk: Compute masks for fractional_divider clk when needed.
There is no real need to pre-compute mmask and nmask when handling
fractional_divider clk.

They can be computed when needed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/0fd6357242c974259c9e034c6e28a0391c480bf0.1680423909.git.christophe.jaillet@wanadoo.fr
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2023-04-05 12:09:26 -07:00
Andy Shevchenko
76c340e93f clk: fractional-divider: Regroup inclusions
For the better maintenance regroup inclusions as follows:
- split CCF related headers in its own group
- order groups from generic to particular
- sort each group alphabetically

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221122130732.48537-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-11-22 18:19:39 -08:00
Andy Shevchenko
ac49a19280 clk: fractional-divider: Show numerator and denominator in debugfs
It's very useful to see what are the values of the fractional divider.
For that, add respective debugfs files.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221122130732.48537-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-11-22 18:19:39 -08:00
Andy Shevchenko
7fffdb7773 clk: fractional-divider: Split out clk_fd_get_div() helper
Split out clk_fd_get_div() helper for the future use elsewhere.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221122130732.48537-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-11-22 18:19:38 -08:00
Tom Rix
7c55e8efd2 clk: cleanup comments
For spdx
Space instead of tab before spdx tag

Removed repeated works
the, to, two

Replacements
much much to a much
'to to' to 'to do'
aready to already
Comunications to Communications
freqency to frequency

Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20220222195153.3817625-1-trix@redhat.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2022-03-11 18:22:15 -08:00
Andy Shevchenko
e81b917a78 clk: fractional-divider: Document the arithmetics used behind the code
It appears that some code lines raise the question why they are needed
and how they are participated in the calculus of the resulting values.

Document this in a form of the top comment in the module file.

Reported-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210812170025.67074-4-andriy.shevchenko@linux.intel.com
[sboyd@kernel.org: Remove "die" as it isn't relevant]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2021-08-12 12:42:00 -07:00
Andy Shevchenko
82f53f9ee5 clk: fractional-divider: Introduce POWER_OF_TWO_PS flag
The newly introduced POWER_OF_TWO_PS flag, when set, makes the flow
to skip the assumption that the caller will use an additional 2^scale
prescaler to get the desired clock rate.

Reported-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210812170025.67074-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2021-08-12 12:42:00 -07:00
Andy Shevchenko
4e7cf74fa3 clk: fractional-divider: Export approximation algorithm to the CCF users
At least one user currently duplicates some functions that are provided
by fractional divider module. Let's export approximation algorithm and
replace the open-coded variant.

As a bonus the exported function will get better documentation in place.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20210812170025.67074-1-andriy.shevchenko@linux.intel.com
[sboyd@kernel.org: Add header guard because why not]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2021-08-12 12:41:47 -07:00
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
Stephen Boyd
0caf000817 Merge branch 'clk-ti' into clk-next
* clk-ti:
  clk: Remove CLK_IS_BASIC clk flag
  clk: ti: dra7: disable the RNG and TIMER12 clkctrl clocks on HS devices
  clk: ti: dra7x: prevent non-existing clkctrl clocks from registering
  ARM: omap2+: hwmod: drop CLK_IS_BASIC flag usage
  clk: ti: export the omap2_clk_is_hw_omap call
2019-05-07 11:46:02 -07:00
Stephen Boyd
90b6c5c73c clk: Remove CLK_IS_BASIC clk flag
This flag was historically used to indicate that a clk is a "basic" type
of clk like a mux, divider, gate, etc. This never turned out to be very
useful though because it was hard to cleanly split "basic" clks from
other clks in a system. This one flag was a way for type introspection
and it just didn't scale. If anything, it was used by the TI clk driver
to indicate that a clk_hw wasn't contained in the SoC specific clk
structure. We can get rid of this define now that TI is finding those
clks a different way.

Cc: Tero Kristo <t-kristo@ti.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: <linux-mips@vger.kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: <linux-pwm@vger.kernel.org>
Cc: <linux-amlogic@lists.infradead.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-26 10:40:49 -07:00
Jonas Gorski
5834fd75e6 clk: core: replace clk_{readl,writel} with {readl,writel}
Now that clk_{readl,writel} is just an alias for {readl,writel}, we can
switch all users of clk_* to use the accessors directly and remove the
helpers.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
[sboyd@kernel.org: Also convert renesas file so that this can be
compile independently]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-23 10:57:49 -07:00
Jonas Gorski
58a2b4c9bd clk: fractional-divider: add explicit big endian support
Add a clock specific flag to switch register accesses to big endian, to
allow runtime configuration of big endian fractional divider clocks.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-23 10:57:48 -07:00
Katsuhiro Suzuki
d13501a2be clk: fractional-divider: check parent rate only if flag is set
Custom approximation of fractional-divider may not need parent clock
rate checking. For example Rockchip SoCs work fine using grand parent
clock rate even if target rate is greater than parent.

This patch checks parent clock rate only if CLK_SET_RATE_PARENT flag
is set.

For detailed example, clock tree of Rockchip I2S audio hardware.
  - Clock rate of CPLL is 1.2GHz, GPLL is 491.52MHz.
  - i2s1_div is integer divider can divide N (N is 1~128).
    Input clock is CPLL or GPLL. Initial divider value is N = 1.
    Ex) PLL = CPLL, N = 10, i2s1_div output rate is
      CPLL / 10 = 1.2GHz / 10 = 120MHz
  - i2s1_frac is fractional divider can divide input to x/y, x and
    y are 16bit integer.

CPLL --> | selector | ---> i2s1_div -+--> | selector | --> I2S1 MCLK
GPLL --> |          | ,--------------'    |          |
                      `--> i2s1_frac ---> |          |

Clock mux system try to choose suitable one from i2s1_div and
i2s1_frac for master clock (MCLK) of I2S1.

Bad scenario as follows:
  - Try to set MCLK to 8.192MHz (32kHz audio replay)
    Candidate setting is
    - i2s1_div: GPLL / 60 = 8.192MHz
    i2s1_div candidate is exactly same as target clock rate, so mux
    choose this clock source. i2s1_div output rate is changed
    491.52MHz -> 8.192MHz

  - After that try to set to 11.2896MHz (44.1kHz audio replay)
    Candidate settings are
    - i2s1_div : CPLL / 107 = 11.214945MHz
    - i2s1_frac: i2s1_div   = 8.192MHz
      This is because clk_fd_round_rate() thinks target rate
      (11.2896MHz) is higher than parent rate (i2s1_div = 8.192MHz)
      and returns parent clock rate.

Above is current upstreamed behavior. Clock mux system choose
i2s1_div, but this clock rate is not acceptable for I2S driver, so
users cannot replay audio.

Expected behavior is:
  - Try to set master clock to 11.2896MHz (44.1kHz audio replay)
    Candidate settings are
    - i2s1_div : CPLL / 107          = 11.214945MHz
    - i2s1_frac: i2s1_div * 147/6400 = 11.2896MHz
                 Change i2s1_div to GPLL / 1 = 491.52MHz at same
                 time.

If apply this commit, clk_fd_round_rate() calls custom approximate
function of Rockchip even if target rate is higher than parent.
Custom function changes both grand parent (i2s1_div) and parent
(i2s_frac) settings at same time. Clock mux system can choose
i2s1_frac and audio works fine.

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
[sboyd@kernel.org: Make function into a macro instead]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-02-22 00:11:47 -08:00
Stephen Boyd
58c05c823b Merge branches 'clk-imx7ulp', 'clk-imx6-fixes', 'clk-imx-fixes', 'clk-imx8qxp' and 'clk-imx8mq' into clk-next
- NXP i.MX7ULP SoC clock support
 - Support for i.MX8QXP SoC clocks
 - Support for NXP i.MX8MQ clock controllers

* clk-imx7ulp:
  clk: imx: add imx7ulp clk driver
  clk: imx: implement new clk_hw based APIs
  clk: imx: make mux parent strings const
  dt-bindings: clock: add imx7ulp clock binding doc
  clk: imx: add imx7ulp composite clk support
  clk: imx: add pfdv2 support
  clk: imx: add pllv4 support
  clk: fractional-divider: add CLK_FRAC_DIVIDER_ZERO_BASED flag support
  clk: imx: add gatable clock divider support

* clk-imx6-fixes:
  clk: imx6q: handle ENET PLL bypass
  clk: imx6q: optionally get CCM inputs via standard clock handles
  clk: imx6q: reset exclusive gates on init

* clk-imx-fixes:
  clk: imx6q: add DCICx clocks gate
  clk: imx6sl: ensure MMDC CH0 handshake is bypassed
  clk: imx7d: remove UART1 clock setting

* clk-imx8qxp:
  clk: imx: add imx8qxp lpcg driver
  clk: imx: add lpcg clock support
  clk: imx: add imx8qxp clk driver
  clk: imx: add scu clock common part
  clk: imx: add configuration option for mmio clks
  dt-bindings: clock: add imx8qxp lpcg clock binding
  dt-bindings: clock: imx8qxp: add SCU clock IDs
  firmware: imx: add pm svc headfile
  dt-bindings: fsl: scu: update power domain binding
  firmware: imx: remove resource id enums
  dt-bindings: imx: add scu resource id headfile

* clk-imx8mq:
  clk: imx: Make the i.MX8MQ CCM clock driver CLK_IMX8MQ dependant
  clk: imx: remove redundant initialization of ret to zero
  clk: imx: Add SCCG PLL type
  clk: imx: Add fractional PLL output clock
  clk: imx: Add clock driver for i.MX8MQ CCM
  clk: imx: Add imx composite clock
  dt-bindings: Add binding for i.MX8MQ CCM
2018-12-14 13:34:47 -08:00
Stephen Boyd
e1bd55e5a5 clk: Tag basic clk types with SPDX
These are all GPL-2.0 files per the existing license text. Replace the
boiler plate with the tag.

Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-12-11 09:57:48 -08:00
A.s. Dong
e983da27f7 clk: fractional-divider: add CLK_FRAC_DIVIDER_ZERO_BASED flag support
Adding CLK_FRAC_DIVIDER_ZERO_BASED flag to indicate the numerator and
denominator value in register are start from 0.

This can be used to support frac dividers like below:
Divider output clock = Divider input clock x [(frac +1) / (div +1)]
where frac/div in register is:
000b - Divide by 1.
001b - Divide by 2.
010b - Divide by 3.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-12-03 11:31:24 -08:00
Elaine Zhang
ec52e46256 clk: fractional-divider: allow overriding of approximation
Fractional dividers may have special requirements concerning numerator
and denominator selection that differ from just getting the best
approximation.

For example on Rockchip socs the denominator must be at least 20 times
larger than the numerator to generate precise clock frequencies.

Therefore add the ability to provide custom approximation functions.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
2017-08-08 17:39:48 +02:00
Stephen Boyd
39b44cff4a clk: fractional-divider: Add hw based registration APIs
Add registration APIs in the clk fractional divider code to
return struct clk_hw pointers instead of struct clk pointers.
This way we hide the struct clk pointer from providers unless
they need to use consumer facing APIs.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-04-19 16:56:28 -07:00
Geliang Tang
5fd9c05c84 clk: move the common clock's to_clk_*(_hw) macros to clk-provider.h
to_clk_*(_hw) macros have been repeatedly defined in many places.
This patch moves all the to_clk_*(_hw) definitions in the common
clock framework to public header clk-provider.h, and drop the local
definitions.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-01-29 12:59:50 -08:00
Andy Shevchenko
0777591e71 clk: fractional-divider: switch to rational best approximation
This patch converts the code to use rational best approximation algorithm which
is much more precise.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-02 11:29:48 -07:00
Andy Shevchenko
934e2536b1 clk: fractional-divider: keep mwidth and nwidth internally
The patch adds mwidth and nwidth fields to the struct clk_fractional_divider
for further usage. While here, use GENMASK() instead of open coding this
functionality.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-02 11:29:46 -07:00
Andy Shevchenko
f7f087c262 clk: fractional-divider: rename prate -> parent_rate
Rename function parameter to be more explicit what it is for. This also makes
it in align with struct clk_ops.

There is no functional change.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-10-02 11:29:45 -07:00
Stephen Boyd
661e2180cf clk: basic-type: Silence warnings about lock imbalances
The basic clock types use conditional locking for the register
accessor spinlocks. Add __acquire() and __release() markings in
the right locations so that sparse isn't tripped up on the
conditional locking.

drivers/clk/clk-mux.c:68:12: warning: context imbalance in 'clk_mux_set_parent' - different lock contexts for basic block
drivers/clk/clk-divider.c:379:12: warning: context imbalance in 'clk_divider_set_rate' - different lock contexts for basic block
drivers/clk/clk-gate.c:71:9: warning: context imbalance in 'clk_gate_endisable' - different lock contexts for basic block
drivers/clk/clk-fractional-divider.c:36:9: warning: context imbalance in 'clk_fd_recalc_rate' - different lock contexts for basic block
drivers/clk/clk-fractional-divider.c:68:12: warning: context imbalance in 'clk_fd_set_rate' - different lock contexts for basic block

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-28 11:59:28 -07:00
Stephen Boyd
d122db7e86 clk: basic-types: Remove useless allocation failure printks
Printing an error on kmalloc() failures is unnecessary. Remove
the print and use *ptr in sizeof() for future-proof code.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-05-14 16:51:50 -07:00
Heikki Krogerus
6b54783620 clk: fractional-divider: support for divider bypassing
If the divider or multiplier values are 0 in the register, bypassing the
divider and returning the parent clock rate in clk_fd_recalc_rate().

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: fixed commitlog typo]
2015-03-12 12:18:47 -07:00
Heiko Stübner
feaefa0ea1 clk: fractional-divider: cast parent_rate to u64 before multiplying
On 32bit architectures, like ARM calculating the fractional rate will
do the multiplication before converting the value to u64 when it gets
assigned to ret, which can produce overflows.

The error in question happened with a parent_rate of 386MHz, m = 3000,
n = 60000, which resulted in a wrong rate value of 15812Hz.

Therefore cast parent_rate to u64 to make sure the multiplication
happens in a 64bit space and produces the correct 192MHz in the example.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-09-10 09:42:37 -07:00
Heikki Krogerus
e2d0e90fae clk: new basic clk type for fractional divider
Fractional divider clocks are fairly common. This adds basic
type for them.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-20 13:34:02 +02:00