[PATCH v3 5/5] OMAP: I2C: Convert i2c driver to use PM runtime api's
Russell King - ARM Linux
linux at arm.linux.org.uk
Tue Sep 28 03:48:40 EDT 2010
On Tue, Sep 28, 2010 at 12:29:01PM +0530, Nayak, Rajendra wrote:
> <snip>...
> > > >
> > > > static int omap_i2c_init(struct omap_i2c_dev *dev)
> > > > @@ -356,6 +333,7 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
> > > > unsigned long fclk_rate = 12000000;
> > > > unsigned long timeout;
> > > > unsigned long internal_clk = 0;
> > > > + struct clk *fclk;
> > > >
> > > > if (dev->rev >= OMAP_I2C_REV_2) {
> > > > /* Disable I2C controller before soft reset */
> > > > @@ -414,7 +392,8 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
> > > > * always returns 12MHz for the functional clock, we can
> > > > * do this bit unconditionally.
> > > > */
> > > > - fclk_rate = clk_get_rate(dev->fclk);
> > > > + fclk = clk_get(dev->dev, "fck");
> > > > + fclk_rate = clk_get_rate(fclk);
> > > >
> > > > /* TRM for 5912 says the I2C clock must be prescaled to be
> > > > * between 7 - 12 MHz. The XOR input clock is typically
> > > > @@ -443,7 +422,8 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
> > > > internal_clk = 9600;
> > > > else
> > > > internal_clk = 4000;
> > > > - fclk_rate = clk_get_rate(dev->fclk) / 1000;
> > > > + fclk = clk_get(dev->dev, "fck");
> > > > + fclk_rate = clk_get_rate(fclk) / 1000;
> > >
> > > You don't put the clk after getting it and using it once?
> >
> > clk_get needs an equivalent clk_put and not clk_get_rate. clk_get_rate
> > is used to merely know the existing rate of the clock.
>
> Sorry, I guess you did mean the clk_get above the clk_get_rate does not have
> an equivalent clk_put.
> I could put a clk_put for readability, but a clk_put on OMAP actually does map
> to an empty function.
> See arch/arm/plat-omap/include/plat/clkdev.h
> clk_get merely returns a pointer to the clk struct and does not do any usecounting,
> hence a clk_put does not do anything.
That's no reason to avoid using it.
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