On Thu, May 28, 2020 at 12:33:10PM +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 i2c/for-next (5.7-rc4): > base-commit: 2a41d0f91443 Merge branch 'i2c/for-5.8' into i2c/for-next > > Note new vendor prefix for Baikal-T1 System I2C device is 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. > > Link: https://lore.kernel.org/linux-i2c/20200526215528.16417-1-Sergey.Semin@baikalelectronics.ru/ > Changelog v4: > - Rebase on top of the i2c/for-next branch. > - Use PTR_ERR_OR_ZERO() helper in the bt1_i2c_request_regs() and > in the dw_i2c_plat_request_regs() methods. > - Discard devm_platform_get_and_ioremap_resource() utilization. > - Discard patch "scripts/dtc: check: Add 10bit/slave i2c reg flags > support" since it must be merged in to the dtc upstream repository. > > Link: https://lore.kernel.org/linux-i2c/20200527120111.5781-1-Sergey.Semin@baikalelectronics.ru > Changelog v5: > - Replace or-assignment with just assignment operator when getting > the quirk flags. > - Keep alphabetical order of the include statements. > - Discard explicit u16-type cast in the dw_reg_write_word() method. > > Link: https://lore.kernel.org/linux-i2c/20200527153046.6172-1-Sergey.Semin@baikalelectronics.ru > Changelog v6: > - Add commas after the last member of the regmap_config instances > initializers. > - Replace the "linux,slave-24c02" compatible string with "atmel,24c02" one > so the DT example would be perceived as a normal DW I2C master mode. > > Signed-off-by: Serge Semin > Cc: Alexey Malahov > Cc: Maxim Kaurkin > Cc: Pavel Parkhomenko > Cc: Ramil Zaripov > Cc: Ekaterina Skachko > Cc: Vadim Vlasov > Cc: Alexey Kolotnikov > Cc: Thomas Bogendoerfer > Cc: Andy Shevchenko > Cc: Mika Westerberg > Cc: Rob Herring > 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 (11): > dt-bindings: i2c: Convert DW I2C binding to DT schema > dt-bindings: i2c: Convert DW I2C slave to the DW I2C master 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 > Applied to for-next, thanks!