From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
To: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Jason Cooper <jason@lakedaemon.net>,
Grant Likely <grant.likely@secretlab.ca>,
Rob Herring <rob.herring@calxeda.com>,
Rob Landley <rob@landley.net>,
Russell King <linux@arm.linux.org.uk>,
Lior Amsalem <alior@marvell.com>, Andrew Lunn <andrew@lunn.ch>,
Gregory CLEMENT <gregory.clement@free-electrons.com>,
Ben Dooks <ben.dooks@codethink.co.uk>,
devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Stephen Warren <swarren@wwwdotorg.org>
Subject: Re: [PATCH 01/11] pinctrl: mvebu: pinctrl driver core
Date: Mon, 20 Aug 2012 14:51:48 +0200 [thread overview]
Message-ID: <20120820145148.47a69ba4@skate> (raw)
In-Reply-To: <CABJ1b_TCF=Jfb0uuoh-M87n6faezj4OqZ4S_nJLA0yKga2-ioQ@mail.gmail.com>
Hello,
Le Mon, 20 Aug 2012 11:46:14 +0200,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> a écrit :
> >> +uart1: serial@12100 {
> >> + compatible = "ns16550a";
> >> + reg = <0x12100 0x100>;
> >> + reg-shift = <2>;
> >> + interrupts = <7>;
> >> + clock-frequency = <166666667>;
> >
> > It's got nothing to do with this patch, but getting a clock frequency
> > out of the DT instead of getting it from the clk_get_rate(clk) and
> > the clock tree seems absurd... (But maybe this platform does not
> > even have a clk implementation?)
>
> It's of_serial's implementation. I patched that once for getting
> frequency out of "clocks" property but then I got busy with
> porting mach-dove and pinctrl.. Marvell SoCs do have a clk
> implementation and as soon as of_serial can handle "clocks"
> property it will be used for sure. I can remove "clock-frequency"
> from the example anyway as it is not really part of pinctrl
> binding documentation.
We are also working on using the clk framework for the 370/XP support
(my colleague Grégory in Cc has started working on this last week), and
we also want to be able to get the serial clock-frequency from the clk
framework instead of an explicit value in the DT node. But that's a
separate topic :)
> > Is it possible to use devm_* managed devm_kzalloc() for this map
> > so you don't need to free it explicitly?
> >
> > (Maybe not, just checking.)
>
> Hmm, I guess not as I thought I've read not to use devm_kfree when
> you allocate _and_ free stuff on runtime without removing the device
> itself, right?
It is also my understanding that devm_*() functions should be used to
allocate things that should persist until the device is removed. But I
might be wrong here.
> >> +struct mvebu_mpp_ctrl {
> >> + const char *name;
> >> + u8 pid;
> >> + u8 npins;
> >
> > So, there will never be > 256 pins on a Marvell platform?
>
> Well, with all current platforms we are well below 100. I guess
> 256 max (muxable) pins will be enough.
Agreed, and this structure is completely internal to the kernel, so we
can easily change it in the future if needed.
> >> + * struct mvebu_mpp_ctrl_setting - describe a mpp ctrl setting
> >> + * @val: ctrl setting value
> >
> > It is not obvious to me what this means, it it possible to elaborate
> > on how this member is defined and used?
>
> Well, I see if I can clarify the description but wrt the datasheet it
> _should_ be quite obvious.
I think the setting/function/group/control terminology would benefit
from an explanation, as it isn't very easy to figure out what all these
words mean in the context of the pinctrl-mvebu driver.
> In some internal review with Andrew I also added a spinlock to
> mvebu_pinconf_get/_set that will protect all calls to generic and specific
> _get/_set register accesses. Moreover, I replaced clk_get_sys in pinctrl-dove
> with the devm_ counterpart and removed the explicit clk_put.
Yes, I had seen this discussion, but I am not sure it is needed: it
seems the pinctrl core calls all the pinconf_set/pinconf_get methods
with the pinctrl_mutex held. When I wrote an initial pinctrl driver for
370/XP I had the same question as Andrew and my conclusion was that the
locking done by the pinctrl subsystem core was sufficient.
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
next prev parent reply other threads:[~2012-08-20 12:52 UTC|newest]
Thread overview: 136+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-11 12:56 [PATCH 00/11] pinctrl: mvebu: pinctrl driver Sebastian Hesselbarth
2012-08-11 12:56 ` [PATCH 01/11] pinctrl: mvebu: pinctrl driver core Sebastian Hesselbarth
2012-08-20 9:09 ` Linus Walleij
2012-08-20 9:46 ` Sebastian Hesselbarth
2012-08-20 12:51 ` Thomas Petazzoni [this message]
2012-08-20 14:18 ` Linus Walleij
2012-08-20 14:51 ` Sebastian Hesselbarth
2012-08-25 8:22 ` Andrew Lunn
2012-08-20 14:11 ` Linus Walleij
2012-08-11 12:56 ` [PATCH 02/11] pinctrl: mvebu: dove pinctrl driver Sebastian Hesselbarth
2012-08-20 13:43 ` Linus Walleij
2012-08-20 14:43 ` Sebastian Hesselbarh
2012-08-20 17:16 ` Thomas Petazzoni
2012-08-11 12:56 ` [PATCH 03/11] pinctrl: mvebu: kirkwood " Sebastian Hesselbarth
2012-08-20 13:49 ` Linus Walleij
2012-08-27 13:43 ` Ben Dooks
2012-08-27 19:19 ` Sebastian Hesselbarth
2012-08-27 20:02 ` Stephen Warren
2012-08-11 12:56 ` [PATCH 04/11] pinctrl: mvebu: add pinctrl driver for Armada 370 Sebastian Hesselbarth
2012-08-20 14:25 ` Linus Walleij
2012-08-20 16:48 ` Sebastian Hesselbarth
2012-08-20 17:36 ` Thomas Petazzoni
2012-08-20 18:01 ` Sebastian Hesselbarth
2012-08-20 18:51 ` Thomas Petazzoni
2012-08-21 7:12 ` Gregory CLEMENT
2012-08-11 12:56 ` [PATCH 05/11] pinctrl: mvebu: add pinctrl driver for Armada XP Sebastian Hesselbarth
2012-08-20 14:26 ` Linus Walleij
2012-08-11 12:56 ` [PATCH 06/11] ARM: mvebu: add pinctrl device in DT for Armada 370/XP SoCs Sebastian Hesselbarth
2012-08-20 14:27 ` Linus Walleij
2012-08-11 12:56 ` [PATCH 07/11] ARM: mvebu: Add pinctrl support to Armada XP SoCs Sebastian Hesselbarth
2012-08-20 14:27 ` Linus Walleij
2012-08-11 12:56 ` [PATCH 08/11] ARM: mvebu: Add pinctrl support to Armada 370 SoC Sebastian Hesselbarth
2012-08-20 14:28 ` Linus Walleij
2012-08-11 12:56 ` [PATCH 09/11] ARM: mvebu: adjust Armada XP evaluation board DTS Sebastian Hesselbarth
2012-08-20 14:28 ` Linus Walleij
2012-08-11 12:56 ` [PATCH 10/11] arm: mvebu: enable PINCTRL usage Sebastian Hesselbarth
2012-08-20 14:29 ` Linus Walleij
2012-08-11 12:56 ` [PATCH 11/11] arm: mvebu: add pinctrl support in defconfig Sebastian Hesselbarth
2012-08-20 14:31 ` Linus Walleij
2012-08-20 14:54 ` Sebastian Hesselbarth
2012-08-20 17:37 ` Thomas Petazzoni
2012-08-20 8:12 ` [PATCH 00/11] pinctrl: mvebu: pinctrl driver Linus Walleij
2012-08-22 8:22 ` [PATCH v2 0/9] " Sebastian Hesselbarth
2012-08-22 8:22 ` [PATCH v2 1/9] pinctrl: mvebu: pinctrl driver core Sebastian Hesselbarth
2012-08-22 20:43 ` Stephen Warren
2012-08-23 9:45 ` Sebastian Hesselbarth
2012-08-23 17:54 ` Stephen Warren
2012-08-23 20:31 ` Sebastian Hesselbarth
2012-08-23 21:26 ` Stephen Warren
2012-08-23 23:01 ` Sebastian Hesselbarth
2012-08-24 3:34 ` Stephen Warren
2012-08-25 15:53 ` Sebastian Hesselbarth
2012-08-27 4:33 ` Stephen Warren
2012-09-02 7:30 ` Linus Walleij
2012-09-02 8:27 ` Sebastian Hesselbarth
2012-09-03 9:32 ` Linus Walleij
2012-09-03 19:47 ` Jason Cooper
2012-09-09 19:56 ` Jason Cooper
2012-08-22 8:22 ` [PATCH v2 2/9] pinctrl: mvebu: dove pinctrl driver Sebastian Hesselbarth
2012-08-22 8:22 ` [PATCH v2 3/9] pinctrl: mvebu: kirkwood " Sebastian Hesselbarth
2012-08-22 8:22 ` [PATCH v2 4/9] pinctrl: mvebu: add pinctrl driver for Armada 370 Sebastian Hesselbarth
2012-08-22 8:22 ` [PATCH v2 5/9] pinctrl: mvebu: add pinctrl driver for Armada XP Sebastian Hesselbarth
2012-08-22 8:22 ` [PATCH v2 6/9] ARM: mvebu: add pinctrl device in DT for Armada 370/XP SoCs Sebastian Hesselbarth
2012-08-22 8:22 ` [PATCH v2 7/9] ARM: mvebu: Add pinctrl support to Armada XP SoCs Sebastian Hesselbarth
2012-08-22 20:45 ` Stephen Warren
2012-08-22 8:22 ` [PATCH v2 8/9] ARM: mvebu: Add pinctrl support to Armada 370 SoC Sebastian Hesselbarth
2012-08-22 20:46 ` Stephen Warren
2012-08-22 8:22 ` [PATCH v2 9/9] ARM: mvebu: adjust Armada XP evaluation board DTS Sebastian Hesselbarth
2012-09-10 8:39 ` [PATCH v3 0/9] pinctrl: mvebu: pinctrl driver Sebastian Hesselbarth
2012-09-10 8:39 ` [PATCH v3 1/9] pinctrl: mvebu: pinctrl driver core Sebastian Hesselbarth
2012-09-10 15:39 ` Linus Walleij
2012-09-11 14:44 ` Thomas Petazzoni
2012-09-11 22:17 ` Stephen Warren
2012-09-12 6:04 ` Linus Walleij
2012-09-12 6:54 ` Thomas Petazzoni
2012-09-12 15:50 ` Linus Walleij
2012-09-12 16:01 ` Thomas Petazzoni
2012-09-12 16:17 ` Linus Walleij
2012-09-12 21:10 ` Stephen Warren
2012-09-10 8:39 ` [PATCH v3 2/9] pinctrl: mvebu: dove pinctrl driver Sebastian Hesselbarth
2012-09-10 15:40 ` Linus Walleij
2012-09-11 22:18 ` Stephen Warren
2012-09-10 8:39 ` [PATCH v3 3/9] pinctrl: mvebu: kirkwood " Sebastian Hesselbarth
2012-09-10 15:42 ` Linus Walleij
2012-09-10 8:39 ` [PATCH v3 4/9] pinctrl: mvebu: add pinctrl driver for Armada 370 Sebastian Hesselbarth
2012-09-10 15:43 ` Linus Walleij
2012-09-10 8:39 ` [PATCH v3 5/9] pinctrl: mvebu: add pinctrl driver for Armada XP Sebastian Hesselbarth
2012-09-10 15:43 ` Linus Walleij
2012-09-10 8:39 ` [PATCH v3 6/9] ARM: mvebu: add pinctrl device in DT for Armada 370/XP SoCs Sebastian Hesselbarth
2012-09-11 22:23 ` Stephen Warren
2012-09-12 6:56 ` Thomas Petazzoni
2012-09-12 20:57 ` Stephen Warren
2012-09-10 8:39 ` [PATCH v3 7/9] ARM: mvebu: Add pinctrl support to Armada XP SoCs Sebastian Hesselbarth
2012-09-10 8:39 ` [PATCH v3 8/9] ARM: mvebu: Add pinctrl support to Armada 370 SoC Sebastian Hesselbarth
2012-09-10 8:39 ` [PATCH v3 9/9] ARM: mvebu: adjust Armada XP evaluation board DTS Sebastian Hesselbarth
2012-09-10 15:45 ` [PATCH v3 0/9] pinctrl: mvebu: pinctrl driver Linus Walleij
2012-09-10 15:57 ` Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 00/10] " Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 01/10] pinctrl: mvebu: pinctrl driver core Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 02/10] pinctrl: mvebu: dove pinctrl driver Sebastian Hesselbarth
2013-06-18 11:36 ` Russell King - ARM Linux
2013-06-18 12:01 ` Sebastian Hesselbarth
2013-06-18 15:02 ` Linus Walleij
2013-06-18 15:11 ` Russell King - ARM Linux
2013-06-18 15:23 ` Linus Walleij
2013-06-18 18:33 ` Mark Brown
2012-09-13 15:41 ` [PATCH v4 03/10] pinctrl: mvebu: kirkwood " Sebastian Hesselbarth
2012-09-16 7:46 ` Andrew Lunn
2012-09-16 9:09 ` Sebastian Hesselbarth
2012-09-17 8:45 ` Linus Walleij
2012-09-20 15:30 ` Arnd Bergmann
2012-09-20 18:34 ` Andrew Lunn
2012-09-20 19:28 ` Linus Walleij
2012-09-20 19:36 ` Thomas Petazzoni
2012-09-20 19:51 ` Andrew Lunn
2012-09-21 10:56 ` Ben Dooks
2012-09-21 18:14 ` Linus Walleij
2012-09-16 12:40 ` Jason Cooper
2012-09-17 1:55 ` Nicolas Pitre
2012-09-17 6:36 ` Sebastian Hesselbarth
2012-09-17 8:32 ` Andrew Lunn
2012-09-18 18:59 ` Andrew Lunn
2012-09-13 15:41 ` [PATCH v4 04/10] pinctrl: mvebu: add pinctrl driver for Armada 370 Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 05/10] pinctrl: mvebu: add pinctrl driver for Armada XP Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 06/10] ARM: mvebu: Add pinctrl support to Armada XP SoCs Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 07/10] ARM: mvebu: Add pinctrl support to Armada 370 SoC Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 08/10] ARM: mvebu: adjust Armada XP evaluation board DTS Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 09/10] arm: mvebu: split Kconfig options for Armada 370 and XP Sebastian Hesselbarth
2012-09-13 15:41 ` [PATCH v4 10/10] arm: mvebu: select the pinctrl drivers for Armada 370 and Armada XP platforms Sebastian Hesselbarth
2012-09-13 15:48 ` [PATCH v4 00/10] pinctrl: mvebu: pinctrl driver Thomas Petazzoni
2012-09-14 16:41 ` Stephen Warren
2012-09-20 8:13 ` [PATCH 00/11] " Linus Walleij
2012-09-20 8:17 ` Sebastian Hesselbarth
2012-09-20 9:04 ` Thomas Petazzoni
2012-09-20 10:02 ` Andrew Lunn
2012-09-20 10:32 ` Thomas Petazzoni
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