|From:||Mike Turquette <firstname.lastname@example.org>|
|Subject:||[PATCH v2 0/4] [RFC] reentrancy in the common clk framework|
|Date:||Wed, 15 Aug 2012 16:43:30 -0700|
|Cc:||email@example.com, firstname.lastname@example.org, Mike Turquette <email@example.com>, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org|
The second version of the reentrancy/dvfs rfc differs from the original in that the former used per-clk mutexes and this version uses a global lock to protect access to a per-clk enum. The enum can be in one of two states, LOCKED or UNLOCKED. The second patch in the series introduces a new common clk rate-change notifier handler which implements typical dynamic voltage and frequency scaling logic. The third patch uses the aforementioned common dvfs rate-change notifier handler. Instead of implementing the dvfs logic directly (as in [1[) the driver simply registers a notifier handler using the common dvfs infrastructure. Potentially all cpufreq and devfreq users could use this to implement voltage scaling. The fourth patch demonstrates how it is possible to call top-level clk api's reentrantly. This example code switches parents of a mux clock and does prepare/disable directly, without using internal functions. A more interesting application of this might be to have clk_set_parent call clk_prepare_enable clk_disable_unprepare directly when reparenting. There are wide-ranging considerations to the common clk framework in this series; I know some of you will be in San Diego later this month and hopefully I'll get some good feedback there as well as on the list.  http://article.gmane.org/gmane.linux.kernel/1327866 Mike Turquette (4): clk: new locking scheme for reentrancy clk: notifier handler for dynamic voltage scaling cpufreq: omap: scale regulator from clk notifier omap3+: clk: dpll: call clk_prepare directly arch/arm/mach-omap2/dpll3xxx.c | 8 +- drivers/clk/Makefile | 3 +- drivers/clk/clk.c | 354 +++++++++++++++++++++++++++++++++++----- drivers/clk/dvfs.c | 116 +++++++++++++ drivers/cpufreq/omap-cpufreq.c | 85 +++------- include/linux/clk-private.h | 1 + include/linux/clk-provider.h | 4 +- include/linux/clk.h | 27 ++- 8 files changed, 488 insertions(+), 110 deletions(-) create mode 100644 drivers/clk/dvfs.c -- 184.108.40.206
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