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[83.54.30.67]) by smtp.gmail.com with ESMTPSA id l7sm28032530wrn.11.2021.02.16.05.36.18 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 16 Feb 2021 05:36:18 -0800 (PST) From: Sergio Paracuellos To: sboyd@kernel.org Cc: robh+dt@kernel.org, john@phrozen.org, tsbogend@alpha.franken.de, gregkh@linuxfoundation.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-mips@vger.kernel.org, devel@driverdev.osuosl.org, neil@brown.name, linux-kernel@vger.kernel.org Subject: [PATCH v6 0/6] MIPS: ralink: add CPU clock detection and clock driver for MT7621 Date: Tue, 16 Feb 2021 14:36:11 +0100 Message-Id: <20210216133617.22333-1-sergio.paracuellos@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org This patchset ports CPU clock detection for MT7621 from OpenWrt and adds a complete clock plan for the mt7621 SOC. The documentation for this SOC only talks about two registers regarding to the clocks: * SYSC_REG_CPLL_CLKCFG0 - provides some information about boostrapped refclock. PLL and dividers used for CPU and some sort of BUS (AHB?). * SYSC_REG_CPLL_CLKCFG1 - a banch of gates to enable/disable clocks for all or some ip cores. Registers needed for this driver to work are in two already mapped areas in its platform's device tree. These are 'sysc' and 'memc' nodes. Most of other drivers just make use of platform operations defined in 'asm/mach-ralink/ralink_regs.h' but this can be avoided declaring this two nodes to be accesible through syscon. Since these are the only two needed control interfaces for this clock driver that seems to be the correct thing to do. No documentation about a probably existent set of dividers for each ip core is included in the datasheets. So we cannot make anything better, AFAICT. Looking into driver code, and some openWRT patched there are another frequences which are used in some drivers (uart, sd...). According to all of this information the clock plan for this SoC is set as follows: - Main top clock "xtal" from where all the rest of the world is derived. - CPU clock "cpu" derived from "xtal" frequencies and a bunch of register reads and predividers. - BUS clock "bus" derived from "cpu" and with (cpu / 4) MHz. - Fixed clocks from "xtal": * "50m": 50 MHz. * "125m": 125 MHz. * "150m": 150 MHz. * "250m": 250 MHz. * "270m": 270 MHz. We also have a buch of gate clocks with their parents: - "hsdma": "150m" - "fe": "250m" - "sp_divtx": "270m" - "timer": "50m" - "pcm": "270m" - "pio": "50m" - "gdma": "bus" - "nand": "125m" - "i2c": "50m" - "i2s": "270m" - "spi": "bus" - "uart1": "50m" - "uart2": "50m" - "uart3": "50m" - "eth": "50m" - "pcie0": "125m" - "pcie1": "125m" - "pcie2": "125m" - "crypto": "250m" - "shxc": "50m" There was a previous attempt of doing this here[0] but the author (Chuanhong Guo) did not wanted to make assumptions of a clock plan for the platform that time. It seems that now he has a better idea of how the clocks are dispossed for this SoC so he share code[1] where some frequencies and clock parents for the gates are coded from a real mediatek private clock plan. I do really want this to be upstreamed so according to the comments in previous attempt[0] from Oleksij Rempel and the frequencies in code[1] I have tried to do this by myself. All of this patches have been tested in a GNUBee PC1 resulting in a working platform. Changes in v6: - Rewrite bindings to properly access the registers needed for the driver making use of syscon for two different areas: 'sysc' and 'memc'. With this changes architecture dependent include 'asm/mach-ralink/ralink_regs.h' is not needed anymore because we access this two syscons using a phandle through kernel's regmap APIs. Explanation of this two areas is in [2]. - Add new 'mt7621_clk_priv' struct to store there pointers to regmap handlers to be able to use regmap operations from normal clock api functions. Add this pointer in 'mt7621_clk' and 'mt7621_clk_gate' before register its related clocks to make things work. - Add Greg's Acked-by in patches 5 and 6. - Rebase this series on the top of linux-next tag 'next-20210215'. v5 RESEND notes: - I am resending this as I was told to do that. - Please, take into account Rob's comments to DT node patch and my reply with explanation about how are the current device tree nodes for this architecture being used in [2]. Changes in v5: - Avoid the use of syscon. All drivers of this platform are just using platform operations defined in 'asm/mach-ralink/ralink_regs.h'. We also need them for some PLL registers that are not in the sys control area. Hence, since we must use this dependency avoid to define clock driver as a child of the sysc node in the device tree and follow current platform code style. - Update bindings documentation to don't refer the syscon and make remove 'clock-output-names' property from required ones. - Use 'asm/mach-ralink/ralink_regs.h' platform read and write operations instead of regmap from the syscon node. - Remove 'mt7621_clk_provider' and directly declare 'clk_hw_onecell_data' pointer in 'mt7621_clk_init' and pass from there into different register functions. Remove pointers to 'mt7621_clk_provider' in the rest fo structs used in this driver. - Remove MHZ macro and just pass values directly in hertzs. - Avoid 'CLK_IGNORE_UNUSED' flag for gates and add a new function called 'mt7621_prepare_enable_clocks' to prepare all of them to make clocks referenced and don't affect current driver code. - Remove COMPILE_TEST from Kconfig because of the use of especific arch stuff. - Fix commit message where a typo for "frequencies" word was present. - Make use of parent_clk_data in 'CLK_BASE' macro. - Remove MODULE_* macros from code since this is not a module. - Remove not needed includes. - Hardcode "xtal" as parent in FIXED macro. - Change 'else if' clause into 'if' clause since a return statement was being used in 'mt7621_xtal_recalc_rate'. NOTES: - Driver is still being declared using 'CLK_OF_DECLARE' for all the clocks. I have explored the possibility to make some of them available afterwards using 'CLK_OF_DECLARE_DRIVER' for top clocks and the rest using a platform driver. The resulting code was uglier since we only want to use the same device tree node and the top clocks must be copied again for the new platform register stuff to properly have a good hierarchy. New globals needs to be introduced and in this particular case I don't really see the benefits of doing in this way. I am totally ok to have all the clocks registered at early stage since from other drivers perspective we only really need to enable gates. So, I prefer to have them in that way if it is not a real problem, of course. Changes in v4: - Add Acked-by from Rob Herring for binding headers (PATCH 1/6). - Convert bindings to not use syscon phandle and declare clock as a child of the syscon node. Update device tree and binding doc accordly. - Make use of 'syscon_node_to_regmap' in driver code instead of get this using the phandle function. - Properly unregister clocks for the error path of the function 'mt7621_clk_init'. - Include ARRAY_SIZE of fixed clocks in the 'count' to kzalloc of 'clk_data'. - Add new patch changing invalid vendor 'mtk' in favour of 'mediatek' which is the one listed in 'vendor-prefixes.yaml'. Update mt7621 code accordly. I have added this patch inside this series because clk binding is referring syscon node and the string for that node was with not listed vendor. Hence update and have all of this correct in the same series. Changes in v3: - Fix compilation warnings reported by kernel test robot because of ignoring return values of 'of_clk_hw_register' in functions 'mt7621_register_top_clocks' and 'mt7621_gate_ops_init'. - Fix dts file and binding documentation 'clock-output-names'. Changes in v2: - Remove the following patches: * dt: bindings: add mt7621-pll device tree binding documentation. * MIPS: ralink: add clock device providing cpu/ahb/apb clock for mt7621. - Move all relevant clock code to 'drivers/clk/ralink/clk-mt7621.c' and unify there previous 'mt7621-pll' and 'mt7621-clk' into a unique driver and binding 'mt7621-clk'. - Driver is not a platform driver anymore and now make use of 'CLK_OF_DECLARE' because we need clocks available in 'plat_time_init' before setting up the timer for the GIC. - Use new fixed clocks as parents for different gates and deriving from 'xtal' using frequencies in[1]. - Adapt dts file and bindings header and documentation for new changes. - Change MAINTAINERS file to only contains clk-mt7621.c code and mediatek,mt7621-clk.yaml file. [0]: https://www.lkml.org/lkml/2019/7/23/1044 [1]: https://github.com/981213/linux/commit/2eca1f045e4c3db18c941135464c0d7422ad8133 [2]: https://lkml.org/lkml/2020/12/20/47 Sergio Paracuellos (6): dt-bindings: clock: add dt binding header for mt7621 clocks dt: bindings: add mt7621-clk device tree binding documentation clk: ralink: add clock driver for mt7621 SoC staging: mt7621-dts: make use of new 'mt7621-clk' staging: mt7621-dts: use valid vendor 'mediatek' instead of invalid 'mtk' MAINTAINERS: add MT7621 CLOCK maintainer .../bindings/clock/mediatek,mt7621-clk.yaml | 66 +++ MAINTAINERS | 6 + arch/mips/ralink/mt7621.c | 6 +- drivers/clk/Kconfig | 1 + drivers/clk/Makefile | 1 + drivers/clk/ralink/Kconfig | 14 + drivers/clk/ralink/Makefile | 2 + drivers/clk/ralink/clk-mt7621.c | 459 ++++++++++++++++++ drivers/staging/mt7621-dts/gbpc1.dts | 11 - drivers/staging/mt7621-dts/mt7621.dtsi | 87 ++-- include/dt-bindings/clock/mt7621-clk.h | 41 ++ 11 files changed, 635 insertions(+), 59 deletions(-) create mode 100644 Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml create mode 100644 drivers/clk/ralink/Kconfig create mode 100644 drivers/clk/ralink/Makefile create mode 100644 drivers/clk/ralink/clk-mt7621.c create mode 100644 include/dt-bindings/clock/mt7621-clk.h