From: Geert Uytterhoeven <geert@linux-m68k.org>
To: songjun.wu@linux.intel.com
Cc: Arnd Bergmann <arnd@arndb.de>,
Greg KH <gregkh@linuxfoundation.org>,
Hauke Mehrtens <hauke@hauke-m.de>,
hua.ma@linux.intel.com, yixin.zhu@linux.intel.com,
chuanhua.lei@linux.intel.com, qi-ming.wu@intel.com,
Linux MIPS Mailing List <linux-mips@linux-mips.org>,
linux-clk <linux-clk@vger.kernel.org>,
"open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Jiri Slaby <jslaby@suse.com>
Subject: Re: [PATCH v2 14/18] serial: intel: Add CCF support
Date: Mon, 6 Aug 2018 11:29:51 +0200 [thread overview]
Message-ID: <CAMuHMdUJ8-bveoHWOetjrHtq2HNPnf00PidQwJ-kZD2o86KLMw@mail.gmail.com> (raw)
In-Reply-To: <0ab8e6e7-3cc2-8e50-b1f3-99616437f527@linux.intel.com>
Hi Songjun,
On Mon, Aug 6, 2018 at 10:58 AM Wu, Songjun <songjun.wu@linux.intel.com> wrote:
> On 8/6/2018 3:20 PM, Geert Uytterhoeven wrote:
> > On Mon, Aug 6, 2018 at 9:15 AM Wu, Songjun <songjun.wu@linux.intel.com> wrote:
> >> On 8/5/2018 5:03 AM, Arnd Bergmann wrote:
> >>> On Sat, Aug 4, 2018 at 2:43 PM, Greg Kroah-Hartman
> >>> <gregkh@linuxfoundation.org> wrote:
> >>>> On Sat, Aug 04, 2018 at 12:54:22PM +0200, Hauke Mehrtens wrote:
> >>>>> On 08/03/2018 12:30 PM, Greg Kroah-Hartman wrote:
> >>>>>> On Fri, Aug 03, 2018 at 03:33:38PM +0800, Wu, Songjun wrote:
> >>>>> This patch makes it possible to use it with the legacy lantiq code and
> >>>>> also with the common clock framework. I see multiple options to fix this
> >>>>> problem.
> >>>>>
> >>>>> 1. The current approach to have it as a compile variant for a) legacy
> >>>>> lantiq arch code without common clock framework and b) support for SoCs
> >>>>> using the common clock framework.
> >>>>> 2. Convert the lantiq arch code to the common clock framework. This
> >>>>> would be a good approach, but it need some efforts.
> >>>>> 3. Remove the arch/mips/lantiq code. There are still users of this code.
> >>>>> 4. Use the old APIs also for the new xRX500 SoC, I do not like this
> >>>>> approach.
> >>>>> 5. Move lantiq_soc.h to somewhere in include/linux/ so it is globally
> >>>>> available and provide some better wrapper code.
> >>>> I don't really care what you do at this point in time, but you all
> >>>> should know better than the crazy #ifdef is not allowed to try to
> >>>> prevent/allow the inclusion of a .h file. Checkpatch might have even
> >>>> warned you about it, right?
> >>>>
> >>>> So do it correctly, odds are #5 is correct, as that makes it work like
> >>>> any other device in the kernel. You are not unique here.
> >>> The best approach here would clearly be 2. We don't want platform
> >>> specific header files for doing things that should be completely generic.
> >>>
> >>> Converting lantiq to the common-clk framework obviously requires
> >>> some work, but then again the whole arch/mips/lantiq/clk.c file
> >>> is fairly short and maybe not that hard to convert.
> >>>
> >>> >From looking at arch/mips/lantiq/xway/sysctrl.c, it appears that you
> >>> already use the clkdev lookup mechanism for some devices without
> >>> using COMMON_CLK, so I would assume that you can also use those
> >>> for the remaining clks, which would be much simpler. It registers
> >>> one anonymous clk there as
> >>>
> >>> clkdev_add_pmu("1e100c00.serial", NULL, 0, 0, PMU_ASC1);
> >>>
> >>> so why not add replace that with two named clocks and just use
> >>> the same names in the DT for the newer chip?
> >>>
> >>> Arnd
> >> We discussed internally and have another solution for this issue.
> >> Add one lantiq.h in the serial folder, and use "#ifdef preprocessor" in
> >> lantiq.h,
> >> also providing no-op stub functions in the #else case, then call those
> >> functions
> >> unconditionally from lantiq.c to avoid #ifdef in C file.
> >>
> >> To support CCF in legacy product is another topic, is not included in
> >> this patch.
> >>
> >> The implementation is as following:
> >> #ifdef CONFIG_LANTIQ
> >> #include <lantiq_soc.h>
> >> #else
> >> #define LTQ_EARLY_ASC 0
> >> #define CPHYSADDR(_val) 0
> >>
> >> static inline struct clk *clk_get_fpi(void)
> >> {
> >> return NULL;
> >> }
> >> #endif
> > Why not use clkdev_add(), as Arnd suggested?
> > That would be a 3-line patch without introducing a new header file and an ugly
> > #ifdef, which complicates compile coverage testing?
> >
> The reason we add a new head file is also for two macros(LTQ_EARLY_ASC
> and CPHYSADDR)
> used by legacy product. We need to provide the no-op stub for these two
> macro for new product.
No you don't. The line number should not be obtained by comparing the
resource address with a hardcoded base address.
Perhaps the override of port->line should just be removed, as IIRC, the serial
core has already filled in that field with the (next available) line number?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2018-08-06 9:30 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-03 3:02 [PATCH v2 00/18] MIPS: intel: add initial support for Intel MIPS SoCs Songjun Wu
2018-08-03 3:02 ` [PATCH v2 01/18] MIPS: intel: Add " Songjun Wu
2018-08-03 17:49 ` Paul Burton
2018-08-06 9:12 ` Hua Ma
2018-08-03 3:02 ` [PATCH v2 02/18] clk: intel: Add clock driver " Songjun Wu
2018-08-06 15:19 ` Rob Herring
2018-08-08 2:51 ` yixin zhu
2018-08-08 5:50 ` Stephen Boyd
2018-08-08 8:52 ` yixin zhu
2018-08-27 19:09 ` Stephen Boyd
2018-08-29 6:56 ` Zhu, Yi Xin
2018-08-31 17:10 ` Stephen Boyd
2018-09-03 10:47 ` Zhu, Yi Xin
2018-08-29 10:34 ` Zhu, Yi Xin
2018-08-31 17:13 ` Stephen Boyd
2018-09-03 10:52 ` Zhu, Yi Xin
2018-08-03 3:02 ` [PATCH v2 03/18] dt-bindings: clk: Add documentation of grx500 clock controller Songjun Wu
2018-08-06 15:18 ` Rob Herring
2018-08-08 3:08 ` yixin zhu
2018-08-08 14:54 ` Rob Herring
2018-08-03 3:02 ` [PATCH v2 04/18] MIPS: dts: Add initial support for Intel MIPS SoCs Songjun Wu
2018-08-04 11:11 ` Hauke Mehrtens
2018-08-06 9:20 ` Hua Ma
2018-08-03 3:02 ` [PATCH v2 05/18] dt-binding: MIPS: Add documentation of " Songjun Wu
2018-08-06 15:16 ` Rob Herring
2018-08-03 3:02 ` [PATCH v2 06/18] MIPS: dts: Change upper case to lower case Songjun Wu
2018-08-06 15:14 ` Rob Herring
2018-08-03 3:02 ` [PATCH v2 07/18] MIPS: dts: Add aliases node for lantiq danube serial Songjun Wu
2018-08-03 3:02 ` [PATCH v2 08/18] serial: intel: Get serial id from dts Songjun Wu
2018-08-03 5:43 ` Greg Kroah-Hartman
2018-08-06 9:32 ` Wu, Songjun
2018-08-07 7:33 ` Geert Uytterhoeven
2018-08-08 4:05 ` Wu, Songjun
2018-08-08 8:33 ` Geert Uytterhoeven
2018-08-10 8:13 ` Wu, Songjun
2018-08-03 3:02 ` [PATCH v2 09/18] serial: intel: Change ltq_w32_mask to asc_update_bits Songjun Wu
2018-08-03 3:02 ` [PATCH v2 10/18] MIPS: lantiq: Unselect SWAP_IO_SPACE when LANTIQ is selected Songjun Wu
2018-08-03 3:02 ` [PATCH v2 11/18] serial: intel: Use readl/writel instead of ltq_r32/ltq_w32 Songjun Wu
2018-08-03 3:02 ` [PATCH v2 12/18] serial: intel: Rename fpiclk to freqclk Songjun Wu
2018-08-03 3:02 ` [PATCH v2 13/18] serial: intel: Replace clk_enable/clk_disable with clk generic API Songjun Wu
2018-08-03 3:02 ` [PATCH v2 14/18] serial: intel: Add CCF support Songjun Wu
2018-08-03 5:56 ` Greg Kroah-Hartman
2018-08-03 7:33 ` Wu, Songjun
2018-08-03 10:30 ` Greg Kroah-Hartman
2018-08-04 10:54 ` Hauke Mehrtens
2018-08-04 12:43 ` Greg Kroah-Hartman
2018-08-04 21:03 ` Arnd Bergmann
2018-08-06 7:05 ` Wu, Songjun
2018-08-06 7:20 ` Geert Uytterhoeven
2018-08-06 8:58 ` Wu, Songjun
2018-08-06 9:29 ` Geert Uytterhoeven [this message]
2018-08-07 7:18 ` Wu, Songjun
2018-08-07 7:33 ` Geert Uytterhoeven
2018-08-03 3:02 ` [PATCH v2 15/18] serial: intel: Support more platform Songjun Wu
2018-08-03 5:57 ` Greg Kroah-Hartman
2018-08-03 7:21 ` Wu, Songjun
2018-08-05 8:37 ` Christoph Hellwig
2018-08-06 7:20 ` Wu, Songjun
2018-08-03 3:02 ` [PATCH v2 16/18] serial: intel: Reorder the head files Songjun Wu
2018-08-03 3:02 ` [PATCH v2 17/18] serial: intel: Change init_lqasc to static declaration Songjun Wu
2018-08-03 3:02 ` [PATCH v2 18/18] dt-bindings: serial: lantiq: Add optional properties for CCF Songjun Wu
2018-08-13 17:53 ` Rob Herring
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