summaryrefslogtreecommitdiff
path: root/drivers/clk/meson/clk-mpll.c
AgeCommit message (Collapse)Author
2019-12-23clk: let init callback return an error codeJerome Brunet
If the init callback is allowed to request resources, it needs a return value to report the outcome of such a request. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://lkml.kernel.org/r/20190924123954.31561-3-jbrunet@baylibre.com Reviewed-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-05-20clk: meson: mpll: add init callback and regsJerome Brunet
Until now (gx and axg), the mpll setting on boot (whatever the bootloader) was good enough to generate a clean fractional division. It is not the case on the g12a. While moving away from the vendor u-boot, it was noticed the fractional part of the divider was no longer applied. Like on the pll, some magic settings need to applied on the mpll register. This change adds the ability to do that on the mpll driver. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
2019-05-20clk: meson: mpll: properly handle spread spectrumJerome Brunet
The bit 'SSEN' available on some MPLL DSS outputs is not related to the fractional part of the divider but to the function called 'Spread Spectrum'. This function might be used to solve EM issues by adding a jitter on clock signal. This widens the signal spectrum and weakens the peaks in it. While spread spectrum might be useful for some application, it is problematic for others, such as audio. This patch introduce a new flag to the MPLL driver to enable (or not) the spread spectrum function. Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored") Tested-by: Martin Blumenstingl<martin.blumenstingl@googlemail.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
2019-02-02clk: meson: rework and clean drivers dependenciesJerome Brunet
Initially, the meson clock directory only hosted 2 controllers drivers, for meson8 and gxbb. At the time, both used the same set of clock drivers so managing the dependencies was not a big concern. Since this ancient time, entropy did its job, controllers with different requirement and specific clock drivers have been added. Unfortunately, we did not do a great job at managing the dependencies between the controllers and the different clock drivers. Some drivers, such as clk-phase or vid-pll-div, are compiled even if they are useless on the target (meson8). As we are adding new controllers, we need to be able to pick a driver w/o pulling the whole thing. The patch aims to clean things up by: * providing a dedicated CONFIG_ for each clock drivers * allowing clock drivers to be compiled as a modules, if possible * stating explicitly which drivers are required by each controller. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Link: https://lkml.kernel.org/r/20190201125841.26785-5-jbrunet@baylibre.com
2018-05-21clk: meson: mpll: add round closest supportJerome Brunet
Allow the mpll driver to round the requested rate up if CLK_MESON_MPLL_ROUND_CLOSEST is set and it provides a rate closer to the requested rate. Acked-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Martin Blumenstingl<martin.blumenstingl@googlemail.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
2018-05-18clk: meson: use SPDX license identifiers consistentlyJerome Brunet
Replace every license notices in drivers/clk/meson by SPDX license identifiers, as described in license-rules.rst Acked-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
2018-03-13clk: meson: split divider and gate part of mpllJerome Brunet
The mpll clock is a kind of fractional divider which can gate. When the RW operation have been added, enable/disable ops have been mistakenly inserted in this driver. These ops are essentially a poor copy/paste of the generic gate ops. This change removes the gate ops from the mpll driver and inserts a generic gate clock on each mpll divider, simplifying the mpll driver and reducing code duplication. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
2018-03-13clk: meson: migrate mplls clocks to clk_regmapJerome Brunet
Rework meson mpll driver to use clk_regmap and move meson8b, gxbb and axg clocks using meson_clk_mpll to clk_regmap Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
2018-02-12clk: meson: add axg misc bit to the mpll driverJerome Brunet
On axg, the rate of the mpll is stuck as if sdm value was 4 and could not change (expect for mpll2 strangely). Looking at the vendor kernel, it turns out a new magic bit from the undocumented HHI_PLL_TOP_MISC register is required. Setting this bit solves the problem and the mpll rates are back to normal Fixes: 78b4af312f91 ("clk: meson-axg: add clock controller drivers") Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
2017-12-23clk: meson: mpll: use 64-bit maths in params_from_rateMartin Blumenstingl
"rem * SDM_DEN" can easily overflow on the 32-bit Meson8 and Meson8b SoCs if the "remainder" (after the division operation) is greater than 262143Hz. This is likely to happen since the input clock for the MPLLs on Meson8 and Meson8b is "fixed_pll", which is running at a rate of 2550MHz. One example where this was observed to be problematic was the Ethernet clock calculation (which takes MPLL2 as input). When requesting a rate of 125MHz there is a remainder of 2500000Hz. The resulting MPLL2 rate before this patch was 127488329Hz. The resulting MPLL2 rate after this patch is 124999103Hz. Commit b609338b26f5 ("clk: meson: mpll: use 64bit math in rate_from_params") already fixed a similar issue in rate_from_params. Fixes: 007e6e5c5f01d3 ("clk: meson: mpll: add rw operation") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
2017-08-01clk: meson: mpll: fix mpll0 fractional part ignoredJerome Brunet
mpll0 clock is special compared to the other mplls. It needs another bit (ssen) to be set to activate the fractional part the mpll divider Fixes: 007e6e5c5f01 ("clk: meson: mpll: add rw operation") Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
2017-04-07clk: meson: mpll: use 64bit math in rate_from_paramsMartin Blumenstingl
On Meson8b the MPLL parent clock (fixed_pll) has a rate of 2550MHz. Multiplying this with SDM_DEN results in a value greater than 32bits. This is not a problem on the 64bit Meson GX SoCs, but it may result in undefined behavior on the older 32bit Meson8b SoC. While rate_from_params was only introduced recently to make the math reusable from _round_rate and _recalc_rate the original bug exists much longer. Fixes: 1c50da4f27 ("clk: meson: add mpll support") Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> [as discussed on the ml, use DIV_ROUND_UP_ULL] Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
2017-04-07clk: meson: mpll: fix division by zero in rate_from_paramsMartin Blumenstingl
According to the public datasheet all register bits in HHI_MPLL_CNTL7, HHI_MPLL_CNTL8 and HHI_MPLL_CNTL9 default to zero. On all GX SoCs these seem to be initialized by the bootloader to some default value. However, on my Meson8 board they are not initialized, leading to a division by zero in rate_from_params as the math is: (parent_rate * SDM_DEN) / ((SDM_DEN * 0) + 0) According to the datasheet, the minimum n2 value is 4. The rate provided by the clock when n2 is less than this minimum is unpredictable. In such case, we report an error. Although the rate_from_params function was only introduced recently the original bug has been there for much longer. It was only exposed recently when the MPLL clocks were added to the Meson8b clock driver. Fixes: 1c50da4f27 ("clk: meson: add mpll support") Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
2017-03-27clk: meson: mpll: correct N2 maximum valueJerome Brunet
Gxbb datasheet says N2 maximum value is 127 but the register field is 9 bits wide, the maximum value should 511. Test shows value greater than 127, all the way to 511, works well Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Michael Turquette <mturquette@baylibre.com> Link: lkml.kernel.org/r/20170309104154.28295-9-jbrunet@baylibre.com
2017-03-27clk: meson: mpll: add rw operationJerome Brunet
This patch adds new callbacks to the meson-mpll driver to control and set the pll rate. For this, we also need to add the enable bit and sdm enable bit. The corresponding parameters are added to mpll data structure. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Michael Turquette <mturquette@baylibre.com> Link: lkml.kernel.org/r/20170309104154.28295-6-jbrunet@baylibre.com
2016-06-22clk: meson: add mpll supportMichael Turquette
MPLLs are adjustable rate clocks derived from PLLs. On both Meson8b and GXBB they appear to be only derived from fixed_pll. Add support for these clock types so that they can be added to their respective drivers. Tested-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Michael Turquette <mturquette@baylibre.com>