[PATCH V3 3/3] ARM: clk-imx6q: Add missing lvds and anaclk clock to the clock tree
shawn.guo at freescale.com
Sun Aug 17 23:06:07 PDT 2014
On Mon, Aug 11, 2014 at 11:09:36AM +0800, Shengjiu Wang wrote:
> On Sat, Aug 09, 2014 at 09:58:42PM +0800, Shawn Guo wrote:
> > On Fri, Aug 08, 2014 at 03:02:49PM +0800, Shengjiu Wang wrote:
> > > @@ -176,8 +182,12 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
> > > * the "output_enable" bit as a gate, even though it's really just
> > > * enabling clock output.
> > > */
> > > - clk[IMX6QDL_CLK_LVDS1_GATE] = imx_clk_gate("lvds1_gate", "lvds1_sel", base + 0x160, 10);
> > > - clk[IMX6QDL_CLK_LVDS2_GATE] = imx_clk_gate("lvds2_gate", "lvds2_sel", base + 0x160, 11);
> > > + clk[IMX6QDL_CLK_LVDS1_GATE] = imx_clk_gate2("lvds1_gate", "lvds1_sel", base + 0x160, 10);
> > > + clk[IMX6QDL_CLK_LVDS2_GATE] = imx_clk_gate2("lvds2_gate", "lvds2_sel", base + 0x160, 11);
> > I do not think you can simply change to use imx_clk_gate2() here. It's
> > designed for those CCGR gate clocks, each of which is controlled by two
> > bits.
> > Shawn
> As Lucas Stach's suggestion, we need to do add some method for mutually exclusive clock,
> lvds1_gate with lvds1_in, lvds2_gate with lvds2_in. I add imx_clk_gate2_exclusive() function in clk-gate2.c.
> So I change imx_clk_gate() to imx_clk_gate2() here.
> As you said, this is not good solution.
It's not just a "not good" solution but wrong and broken one. The net
result of that is if you call clk_enable() on lvds1_gate, both bit 10
and 11 will be set.
> So I need your suggestion, how can I do?
I guess we will need a new clock type to handle such mutually exclusive
clocks, rather than patching clk-gate2.
> First, is it allowable that to add imx_clk_gate2_exclusive() function, is there a more better way?
Again, this is completely wrong.
> second, or should I change the clk-gate.c to add exclusive control?
If such mutually exclusive clocks are somehow common across different
clock controllers, we can propose to change clk-gate.c for handling
them. But I'm not sure this is a common case.
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