| Message ID | 20200526215528.16417-1-Sergey.Semin@baikalelectronics.ru (mailing list archive) |
|---|---|
| Headers | show |
| Series | i2c: designeware: Add Baikal-T1 System I2C support | expand |
On Wed, May 27, 2020 at 12:55:16AM +0300, Serge Semin wrote: > Jarkko, Wolfram, the merge window is upon us, please review/merge in/whatever > the patchset. > > Initially this has been a small patchset which embedded the Baikal-T1 > System I2C support into the DW APB I2C driver as is by using a simplest > way. After a short discussion with Andy we decided to implement what he > suggested (introduce regmap-based accessors and create a glue driver) and > even more than that to provide some cleanups of the code. So here is what > this patchset consists of. > > First of all we've found out that current implementation of scripts/dtc > didn't support i2c dt nodes with 10bit and slave flags set in the > reg property. You'll see an error if you try to dt_binding_check it. > So the very first patch fixes the problem by adding these flags support > into the check_i2c_bus_reg() method. > > Traditionally we converted the plain text-based DT binding to the DT schema > and added Baikal-T1 System I2C device support there. This required to mark > the reg property redundant for Baikal-T1 I2C since its reg-space is > indirectly accessed by means of the System Controller cmd/read/write > registers. > > Then as Andy suggested we replaced the Synopsys DW APB I2C common driver > registers IO accessors into the regmap API methods. This doesn't change > the code logic much, though in two places we managed to replace some bulky > peaces of code with a ready-to-use regmap methods. > > Additionally before adding the glue layer API we initiated a set of cleanups: > - Define components of the multi-object drivers (like i2c-designware-core.o > and i2c-designware-paltform.o) with using `-y` suffixed makefile > variables instead of `-objs` suffixed one. This is encouraged by > Documentation/kbuild/makefiles.rst text since `-objs` is supposed to be used > to build host programs. > - Make DW I2C slave driver depended on the DW I2C core code instead of the > platform one, which it really is. > - Move Intel Baytrail semaphore feature to the platform if-clause of the > kernel config. > > After this we finally can introduce the glue layer API for the DW APB I2C > platform driver. So there are three methods exported from the driver: > i2c_dw_plat_setup(), i2c_dw_plat_clear(), &i2c_dw_plat_dev_pm_ops to > setup, cleanup and add PM operations to the glue driven I2C device. Before > setting the platform DW I2C device up the glue probe code is supposed to > create an instance of DW I2C device generic object and pre-initialize > its `struct device` pointer together with optional platform-specific > flags. In addition to that we converted the MSCC Ocelot SoC I2C specific > code into the glue layer seeing it's really too specific and, which is more > important, isn't that complicated so we could unpin it without much of > worrying to break something. > > Meanwhile we discovered that MODEL_CHERRYTRAIL and MODEL_MASK actually > were no longer used in the code. MODEL_MSCC flag has been discarded since > the MSCC Ocelot I2C code conversion to the glue driver. So now we can get > rid of all the MODEL-specific flags. > > Finally we introduced a glue driver with Baikal-T1 System I2C device > support. The driver probe tries to find a syscon regmap, creates the DW > APB I2C regmap based on it and passes it further to the DW I2C device > descriptor. Then it does normal DW APB I2C platform setup by calling a > generic setup method. Cleanup is straightforward. It's just calling a > generic DW APB I2C clean method. > > This patchset is rebased and tested on the mainline Linux kernel 5.6-rc4: > base-commit: 0e698dfa2822 ("Linux 5.7-rc4") > tag: v5.7-rc4 > > Note new vendor prefix for Baikal-T1 System I2C device will be added in > the framework of the next patchset: > https://lkml.org/lkml/2020/5/6/1047 > scripts/dtc: check: Add 10bit/slave i2c reg flags support Hmm... I don't see this patch.
Jarkko, Wolfram, the merge window is upon us, please review/merge in/whatever the patchset. Initially this has been a small patchset which embedded the Baikal-T1 System I2C support into the DW APB I2C driver as is by using a simplest way. After a short discussion with Andy we decided to implement what he suggested (introduce regmap-based accessors and create a glue driver) and even more than that to provide some cleanups of the code. So here is what this patchset consists of. First of all we've found out that current implementation of scripts/dtc didn't support i2c dt nodes with 10bit and slave flags set in the reg property. You'll see an error if you try to dt_binding_check it. So the very first patch fixes the problem by adding these flags support into the check_i2c_bus_reg() method. Traditionally we converted the plain text-based DT binding to the DT schema and added Baikal-T1 System I2C device support there. This required to mark the reg property redundant for Baikal-T1 I2C since its reg-space is indirectly accessed by means of the System Controller cmd/read/write registers. Then as Andy suggested we replaced the Synopsys DW APB I2C common driver registers IO accessors into the regmap API methods. This doesn't change the code logic much, though in two places we managed to replace some bulky peaces of code with a ready-to-use regmap methods. Additionally before adding the glue layer API we initiated a set of cleanups: - Define components of the multi-object drivers (like i2c-designware-core.o and i2c-designware-paltform.o) with using `-y` suffixed makefile variables instead of `-objs` suffixed one. This is encouraged by Documentation/kbuild/makefiles.rst text since `-objs` is supposed to be used to build host programs. - Make DW I2C slave driver depended on the DW I2C core code instead of the platform one, which it really is. - Move Intel Baytrail semaphore feature to the platform if-clause of the kernel config. After this we finally can introduce the glue layer API for the DW APB I2C platform driver. So there are three methods exported from the driver: i2c_dw_plat_setup(), i2c_dw_plat_clear(), &i2c_dw_plat_dev_pm_ops to setup, cleanup and add PM operations to the glue driven I2C device. Before setting the platform DW I2C device up the glue probe code is supposed to create an instance of DW I2C device generic object and pre-initialize its `struct device` pointer together with optional platform-specific flags. In addition to that we converted the MSCC Ocelot SoC I2C specific code into the glue layer seeing it's really too specific and, which is more important, isn't that complicated so we could unpin it without much of worrying to break something. Meanwhile we discovered that MODEL_CHERRYTRAIL and MODEL_MASK actually were no longer used in the code. MODEL_MSCC flag has been discarded since the MSCC Ocelot I2C code conversion to the glue driver. So now we can get rid of all the MODEL-specific flags. Finally we introduced a glue driver with Baikal-T1 System I2C device support. The driver probe tries to find a syscon regmap, creates the DW APB I2C regmap based on it and passes it further to the DW I2C device descriptor. Then it does normal DW APB I2C platform setup by calling a generic setup method. Cleanup is straightforward. It's just calling a generic DW APB I2C clean method. This patchset is rebased and tested on the mainline Linux kernel 5.6-rc4: base-commit: 0e698dfa2822 ("Linux 5.7-rc4") tag: v5.7-rc4 Note new vendor prefix for Baikal-T1 System I2C device will be added in the framework of the next patchset: https://lkml.org/lkml/2020/5/6/1047 Changelog v2: - Fix the SoB tags. - Use a shorter summary describing the bindings convertion patch. - Patch "i2c: designware: Detect the FIFO size in the common code" has been acked by Jarkko and applied by Wolfram to for-next so drop it from the set. - Patch "i2c: designware: Discard i2c_dw_read_comp_param() function" has been acked by Jarkko and applied by Wolfram to for-next so drop it from the set. - Make sure that "mscc,ocelot-i2c" compatible node may have up to two registers space defined in the DT node, while normal DW I2C controller will have only one registers space. - Add "mscc,ocelot-i2c" DT schema example to test the previous fix. - Declare "unevaluatedProperties" property instead of "additionalProperties" one in the DT schema. - Due to the previous fix we can now discard the dummy boolean properties declaration, since the proper type evaluation will be performed by the generic i2c-controller.yaml schema. - Refactor the DW I2C APB driver related series to address the Andies notes. - Convert DW APB I2C driver to using regmap instead of handwritten accessors. - Use `-y` to build multi-object DW APB drivers. - Fix DW APB I2C slave code dependency. It should depend on I2C_DESIGNWARE_CORE instead I2C_DESIGNWARE_PLATFORM. - Move Baytrail semaphore config to the platform if-clause. - Introduce a glue-layer platform driver API. - Unpin Microsemi Ocelot I2C code into a glue driver. - Remove MODEL_CHERRYTRAIL and MODEL_MASK as no longer needed. - Add support for custom regmap passed from glue driver. - Add Baikal-T1 System I2C support in a dedicated glue layer driver. Link: https://lore.kernel.org/linux-i2c/20200510095019.20981-1-Sergey.Semin@baikalelectronics.ru/ Changelog v3: - Move fixes and less invasive patches to the head of the series. - Add patch "dt-bindings: i2c: Discard i2c-slave flag from the DW I2C example" since Rob says the flag can be discarded until dtc is fixed. - Add patch "i2c: designware: Retrieve quirk flags as early as possible" as a first preparation before adding Baikal-T1 System I2C support. - Add patch "i2c: designware: Move reg-space remapping into a dedicated function" as a second preparation before adding Baikal-T1 System I2C support. - Add patch "i2c: designware: Add Baikal-T1 System I2C support", which integrates the Baikal-T1 I2C support into the DW I2C platform driver. - Get back the reg property being mandatory even if it's Baikal-T1 System I2C DT node. Rob says it has to be in the DT node if there is a dedicated registers range in the System Controller registers space. - Replace if-endif clause around the I2C_DESIGNWARE_BAYTRAIL config with "depends on" operator. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru> Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru> Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru> Cc: Ekaterina Skachko <Ekaterina.Skachko@baikalelectronics.ru> Cc: Vadim Vlasov <V.Vlasov@baikalelectronics.ru> Cc: Alexey Kolotnikov <Alexey.Kolotnikov@baikalelectronics.ru> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: linux-mips@vger.kernel.org Cc: linux-i2c@vger.kernel.org Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Serge Semin (12): scripts/dtc: check: Add 10bit/slave i2c reg flags support dt-bindings: i2c: Convert DW I2C binding to DT schema dt-bindings: i2c: Discard i2c-slave flag from the DW I2C example dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller i2c: designware: Use `-y` to build multi-object modules i2c: designware: slave: Set DW I2C core module dependency i2c: designware: Add Baytrail sem config DW I2C platform dependency i2c: designware: Discard Cherry Trail model flag i2c: designware: Convert driver to using regmap API i2c: designware: Retrieve quirk flags as early as possible i2c: designware: Move reg-space remapping into a dedicated function i2c: designware: Add Baikal-T1 System I2C support .../bindings/i2c/i2c-designware.txt | 73 ------- .../bindings/i2c/snps,designware-i2c.yaml | 156 +++++++++++++++ drivers/i2c/busses/Kconfig | 31 +-- drivers/i2c/busses/Makefile | 17 +- drivers/i2c/busses/i2c-designware-common.c | 178 +++++++++++++----- drivers/i2c/busses/i2c-designware-core.h | 24 +-- drivers/i2c/busses/i2c-designware-master.c | 125 ++++++------ drivers/i2c/busses/i2c-designware-pcidrv.c | 1 - drivers/i2c/busses/i2c-designware-platdrv.c | 102 +++++++++- drivers/i2c/busses/i2c-designware-slave.c | 77 ++++---- scripts/dtc/checks.c | 13 +- 11 files changed, 532 insertions(+), 265 deletions(-) delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-designware.txt create mode 100644 Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml