From mboxrd@z Thu Jan 1 00:00:00 1970 From: joe@perches.com (Joe Perches) Date: Wed, 18 Sep 2013 16:02:41 -0700 Subject: [PATCH v2] clk: si570: Add a driver for SI570 oscillators In-Reply-To: <1379544219-23579-1-git-send-email-soren.brinkmann@xilinx.com> References: <1379544219-23579-1-git-send-email-soren.brinkmann@xilinx.com> Message-ID: <1379545361.1787.87.camel@joe-AO722> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 2013-09-18 at 15:43 -0700, Soren Brinkmann wrote: > Add a driver for SILabs 570, 571, 598, 599 programmable oscillators. > The devices generate low-jitter clock signals and are reprogrammable via > an I2C interface. [] > v2: [] > - use 10000 as MIN and MAX value in usleep_range [] > diff --git a/drivers/clk/clk-si570.c b/drivers/clk/clk-si570.c [] > +static int si570_set_frequency(struct clk_si570 *data, unsigned long frequency) > +{ [] > + /* Applying a new frequency can take up to 10ms */ > + usleep_range(10000, 10000); Generally it's nicer to have an actual range for usleep_range. Is there a bit you could periodically poll to see if the new frequency has been set or is stable so that a 10ms delay isn't always used?