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* [PATCH 0/2] Common struct clk implementation, v8
@ 2010-12-08  2:08 Jeremy Kerr
  2010-12-08  2:08 ` [PATCH 2/2] clk: Generic support for fixed-rate clocks Jeremy Kerr
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Jeremy Kerr @ 2010-12-08  2:08 UTC (permalink / raw)
  To: linux-arm-kernel; +Cc: linux-kernel

[apologies for the resend: missed this series description]

Hi all,

These patches are an attempt to allow platforms to share clock code. At
present, the definitions of 'struct clk' are local to platform code,
which makes allocating and initialising cross-platform clock sources
difficult, and makes it impossible to compile a single image containing
support for two ARM platforms with different struct clks.

The two patches are for the architecture-independent kernel code,
introducing the common clk infrastructure. The changelog for the first
patch includes details about the new clock definitions.

As requested by rmk, I've put together a small series of patches
illustrating the usage of the common struct clock on the ARM imx51
platform. These are available in my git tree:

 git://kernel.ubuntu.com/jk/dt/linux-2.6

in the clk-common-mx51 branch (clk-common..clk-common-mx51). There is
also a port  for versatile (clk-common-versatile) in this tree too.

The approach I've taken with the imx51 port is to temporarly duplicate
the platform-common clock code (ie, for all mxc-based boards) to enable
usage of the common struct clk on one machine (imx51), while leaving the
others as-is. For a proper platform-wide usage of the common struct clk,
we'd be better off doing the whole platform at once. However, mx51 is
the only mxc-based HW I have, hence the duplicated example port.

In the example port, the first change simply converts the mxc's struct
clk to a struct clk_mxc, using the new API.  The subsequent patches move
certain clocks to more specific data structures (eg clk_fixed and
clk_pll) where possible.

Ben Herrenschmidt is looking at using common struct clk code for powerpc
too, hence the kernel-wide approach.

Many thanks to the following for their input:
 * Ben Dooks <ben-linux@fluff.org>
 * Baruch Siach <baruch@tkos.co.il>
 * Russell King <linux@arm.linux.org.uk>
 * Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
 * Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
 * Vincent Guittot <vincent.guittot@linaro.org>

Russell - now that we've had a few platforms ported to the common clk
infrastructure, I believe it's ready to merge. If so, do you want this
in the patch tracker? Otherwise, let me know what needs changing.

Cheers,


Jeremy

--
v8:
 * add atomic clocks, and locking wrappers
 * expand comments on clk and clk_ops

v7:
 * change CLK_INIT to initialise clk->mutex statically

v6:
 * fixed up references to 'clk_operations' in the changelog

v5:
 * uninline main API, and share definitions with !USE_COMMON_STRUCT_CLK
 * add __clk_get
 * delay mutex init
 * kerneldoc for struct clk

v4:
 * use mutex for enable/disable locking
 * DEFINE_CLK -> INIT_CLK, and pass the clk name for mutex init
 * struct clk_operations -> struct clk_ops

v3:
 * do clock usage refcounting in common code
 * provide sample port

v2:
 * no longer ARM-specific
 * use clk_operations

---
Jeremy Kerr (2):
      Add a common struct clk
      clk: Generic support for fixed-rate clocks


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2010-12-13 12:42 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-12-08  2:08 [PATCH 0/2] Common struct clk implementation, v8 Jeremy Kerr
2010-12-08  2:08 ` [PATCH 2/2] clk: Generic support for fixed-rate clocks Jeremy Kerr
2010-12-13 12:14   ` Sascha Hauer
2010-12-13 12:35     ` Jeremy Kerr
2010-12-13 12:42       ` Sascha Hauer
2010-12-08  2:08 ` [PATCH 1/2] Add a common struct clk Jeremy Kerr
2010-12-08 10:33 ` [PATCH 0/2] Common struct clk implementation, v8 Uwe Kleine-König
2010-12-08 10:51   ` Jeremy Kerr

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