Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH 1/9] ARM i.MX51: Add ipu clock support | Date | Wed, 15 Dec 2010 16:40:03 +0100 |
| |
On Thursday 09 December 2010, Sascha Hauer wrote: > +static int clk_ipu_enable(struct clk *clk) > +{ > + u32 reg; > + > + _clk_ccgr_enable(clk); > + > + /* Enable handshake with IPU when certain clock rates are changed */ > + reg = __raw_readl(MXC_CCM_CCDR); > + reg &= ~MXC_CCM_CCDR_IPU_HS_MASK; > + __raw_writel(reg, MXC_CCM_CCDR); > + > + /* Enable handshake with IPU when LPM is entered */ > + reg = __raw_readl(MXC_CCM_CLPCR); > + reg &= ~MXC_CCM_CLPCR_BYPASS_IPU_LPM_HS; > + __raw_writel(reg, MXC_CCM_CLPCR); > + > + return 0; > +}
Why __raw_readl?
The regular accessor function for I/O registers is readl, which handles the access correctly with regard to atomicity, I/O ordering and byteorder.
Arnd
| |